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Sample records for oxygen-enriched combustion air

  1. Combustion Of Porous Graphite Particles In Oxygen Enriched Air

    NASA Technical Reports Server (NTRS)

    Delisle, Andrew J.; Miller, Fletcher J.; Chelliah, Harsha K.

    2003-01-01

    Combustion of solid fuel particles has many important applications, including power generation and space propulsion systems. The current models available for describing the combustion process of these particles, especially porous solid particles, include various simplifying approximations. One of the most limiting approximations is the lumping of the physical properties of the porous fuel with the heterogeneous chemical reaction rate constants [1]. The primary objective of the present work is to develop a rigorous modeling approach that could decouple such physical and chemical effects from the global heterogeneous reaction rates. For the purpose of validating this model, experiments with porous graphite particles of varying sizes and porosity are being performed under normal and micro gravity.

  2. Experimental and kinetic modeling of oxygen-enriched air combustion of municipal solid waste.

    PubMed

    Liu, Guo Hui; Ma, Xiao Qian; Yu, Zhaosheng

    2009-02-01

    The characteristics of oxygen-enriched air combustion of raw municipal solid waste (MSW) were studied by thermogravimetric analysis. Experiments on oxidative pyrolysis of MSW were carried out under different atmospheres (N(2), N(2):O(2)=7:3, N(2):O(2)=5:5, N(2):O(2)=4:6, and N(2):O(2)=2:8) at 30 degrees C/min. Two distinct peaks of weight loss were obtained according to the derivative thermogravimetric curves; one of them is centered on 305 degrees C with about 40% weight loss, and the second is centered on 420 degrees C with about 20% weight loss. Effects of oxygen concentration on the decomposition process and char combustion were analyzed, and then the process of oxygen-enriched air combustion of MSW was divided into four steps. Kinetic parameters were observed by direct non-linear regressions. According to the obtained data, the apparent activation energy and reaction order decreases along with the combustion process, while that of char combustion increases as oxygen concentration increases. PMID:18691862

  3. Study of using oxygen-enriched combustion air for locomotive diesel engines

    SciTech Connect

    Poola, R.B.; Sekar, R.; Assanis, D.N.; Cataldi, G.R.

    1996-10-01

    A thermodynamic simulation is used to study effects of O2-enriched intake air on performance and NO emissions of a locomotive diesel engine. Parasitic power of the air separation membrane required to supply the O2-enriched air is also estimated. For a given constraint on peak cylinder pressure, gross and net power output of an engine operating under different levels of O2 enrichment are compared with those obtained when a high-boost turbocharged engine is used. A 4% increase in peak cylinder pressure can result in 13% increase in net engine power when intake air with 28 vol% O2 is used and fuel injection timing retarded by 4 degrees. When the engine is turbocharged to a higher inlet boost, the same increase in peak cylinder pressure can result in only 4% improvement in power. If part of the higher exhaust enthalpies from the O2 enrichment is recovered, the power requirements of the air separator membrane can be met. O2 enrichment with its higher combustion temperatures reduces emissions of particulates and visible smoke but increases NO emissions (by up to 3 times at 26% O2 content). Therefore, exhaust gas after-treatment and heat recovery would be required if the full potential of O2 enrichment for improving the performance of locomotive diesel engines is to be realized.

  4. REDUCTION OF NOx EMISSION FROM COAL COMBUSTION THROUGH OXYGEN ENRICHMENT

    SciTech Connect

    Western Research Institute

    2006-07-01

    BOC Process Gas Solutions and Western Research Institute (WRI) conducted a pilot-scale test program to evaluate the impact of oxygen enrichment on the emissions characteristics of pulverized coal. The combustion test facility (CTF) at WRI was used to assess the viability of the technique and determine the quantities of oxygen required for NOx reduction from coal fired boiler. In addition to the experimental work, a series of Computational Fluid Dynamics (CFD) simulations were made of the CTF under comparable conditions. A series of oxygen enrichment test was performed using the CTF. In these tests, oxygen was injected into one of the following streams: (1) the primary air (PA), (2) the secondary air (SA), and (3) the combined primary and secondary air. Emission data were collected from all tests, and compared with the corresponding data from the baseline cases. A key test parameter was the burner stoichiometry ratio. A series of CFD simulation models were devised to mimic the initial experiments in which secondary air was enriched with oxygen. The results from these models were compared against the experimental data. Experimental evidence indicated that oxygen enrichment does appear to be able to reduce NOx levels from coal combustion, especially when operated at low over fire air (OFA) levels. The reductions observed however are significantly smaller than that reported by others (7-8% vs. 25-50%), questioning the economic viability of the technique. This technique may find favor with fuels that are difficult to burn or stabilize at high OFA and produce excessive LOI. While CFD simulation appears to predict NO amounts in the correct order of magnitude and the correct trend with staging, it is sensitive to thermal conditions and an accurate thermal prediction is essential. Furthermore, without development, Fluent's fuel-NO model cannot account for a solution sensitive fuel-N distribution between volatiles and char and thus cannot predict the trends seen in the

  5. Final report on the project entitled: Highly Preheated Combustion Air System with/without Oxygen Enrichment for Metal Processing Furnaces

    SciTech Connect

    Arvind Atreya

    2007-02-16

    This work develops and demonstrates a laboratory-scale high temperature natural gas furnace that can operate with/without oxygen enrichment to significantly improve energy efficiency and reduce emissions. The laboratory-scale is 5ft in diameter & 8ft tall. This furnace was constructed and tested. This report demonstrates the efficiency and pollutant prevention capabilities of this test furnace. The project also developed optical detection technology to control the furnace output.

  6. Utilization of oxygen-enriched air in diesel engines: Fundamental considerations

    SciTech Connect

    Lahiri, D.; Mehta, P.S.; Poola, R.B.; Sekar, R.

    1997-09-01

    Utilization of oxygen-enriched air in diesel engines holds potential for low exhaust smoke and particulate emissions. The majority of the oxygen-enriched-air combustion-related studies so far are experimental in nature, where the observed results are understood on an overall basis. This paper deals with the fundamental considerations associated with the oxygen-enriched air-fuel combustion process to enhance understanding of the concept. The increase in adiabatic flame temperature, the composition of exhaust gases at equilibrium, and also the changes in thermodynamic and transport properties due to oxygen-enrichment of standard intake air are computed. The effects of oxygen-enrichment on fuel evaporation rate, ignition delay, and premixed burnt fraction are also evaluated. Appropriate changes in the ignition delay correlation to reflect the effects of oxygen-enrichment are proposed. The notion of oxygen-enrichment of standard intake air as being akin to leaning of the fuel-air mixture is refuted on the basis of the fundamentally different requirements for the oxygen-enriched combustion process.

  7. An oxygen enrichment attachment for use with humidified air

    PubMed Central

    Jebson, P.; Dewar, J.; White, J.

    1974-01-01

    Jebson, P., Dewar, J., and White, J. (1974).Thorax, 29, 371-376. An oxygen enrichment attachment for use with humidified air. An oxygen enrichment attachment is described which fulfils the basic requirements for intubated patients. Using values for tidal volume and inspiratory time found in the type of patients for whom the attachment is intended, a range of mean inspired oxygen concentration has been given for 2, 4, 6, 8, and 10 1/min oxygen flow. Images PMID:4850557

  8. Oxygen-enriched air for MHD power plants

    NASA Technical Reports Server (NTRS)

    Ebeling, R. W., Jr.; Cutting, J. C.; Burkhart, J. A.

    1979-01-01

    Cryogenic air-separation process cycle variations and compression schemes are examined. They are designed to minimize net system power required to supply pressurized, oxygen-enriched air to the combustor of an MHD power plant with a coal input of 2000 MWt. Power requirements and capital costs for oxygen production and enriched air compression for enrichment levels from 13 to 50% are determined. The results are presented as curves from which total compression power requirements can be estimated for any desired enrichment level at any delivery pressure. It is found that oxygen enrichment and recuperative heating of MHD combustor air to 1400 F yields near-term power plant efficiencies in excess of 45%. A minimum power compression system requires 167 MW to supply 330 lb of oxygen per second and costs roughly 100 million dollars. Preliminary studies show MHD/steam power plants to be competitive with plants using high-temperature air preheaters burning gas.

  9. Oxygen enriched combustion system performance study. Phase 2: 100 percent oxygen enriched combustion in regenerative glass melters, Final report

    SciTech Connect

    Tuson, G.B.; Kobayashi, H.; Campbell, M.J.

    1994-08-01

    The field test project described in this report was conducted to evaluate the energy and environmental performance of 100% oxygen enriched combustion (100% OEC) in regenerative glass melters. Additional objectives were to determine other impacts of 100% OEC on melter operation and glass quality, and to verify on a commercial scale that an on-site Pressure Swing Adsorption oxygen plant can reliably supply oxygen for glass melting with low electrical power consumption. The tests constituted Phase 2 of a cooperative project between the United States Department of Energy, and Praxair, Inc. Phase 1 of the project involved market and technical feasibility assessments of oxygen enriched combustion for a range of high temperature industrial heating applications. An assessment of oxygen supply options for these applications was also performed during Phase 1, which included performance evaluation of a pilot scale 1 ton per day PSA oxygen plant. Two regenerative container glass melters were converted to 100% OEC operation and served as host sites for Phase 2. A 75 ton per day end-fired melter at Carr-Lowrey Glass Company in Baltimore, Maryland, was temporarily converted to 100% OEC in mid- 1990. A 350 tpd cross-fired melter at Gallo Glass Company in Modesto, California was rebuilt for permanent commercial operation with 100% OEC in mid-1991. Initially, both of these melters were supplied with oxygen from liquid storage. Subsequently, in late 1992, a Pressure Swing Adsorption oxygen plant was installed at Gallo to supply oxygen for 100% OEC glass melting. The particular PSA plant design used at Gallo achieves maximum efficiency by cycling the adsorbent beds between pressurized and evacuated states, and is therefore referred to as a Vacuum/Pressure Swing Adsorption (VPSA) plant.

  10. Diesel cogeneration plant using oxygen enriched air and emulsified fuels

    SciTech Connect

    Marciniak, T.J.; Cole, R.L.; Sekar, R.R.; Stodolsky, F. ); Eustis, J.N. )

    1990-01-01

    The investigation of oxygen-enriched combustion of alternative fuels in diesel engines at Argonne National Laboratory (ANL) is based on information gathered from two previous Department of Energy programs. The first was the slow-speed diesel engine program which used fuels such as coal-water slurry and coal derived liquid fuels in a slow speed diesel engine. The second was the development of membrane oxygen separation equipment. The results of these programs indicated that using the new membrane oxygen enrichment technology with medium- and high-speed diesel engines would do two things. First, oxygen enrichment could reduce some emissions from stationary diesel engines, particularly smoke, particulates and hydrocarbons while significantly increasing power output. The second, was that it might be possible to use less expensive liquid fuels such as No. 4, No. 6 and residual oil emulsified with water in medium- to high-speed diesel engines. The water would (1) help to eliminate the undesirable increase in nitrogen oxide production when enriched oxygen is used, and (2) by reducing the viscosity of the heavier liquid fuels, make them easier to use in smaller industrial cogeneration applications. This program consists of four steps: preliminary feasibility study, exploratory experiments, system development, and demonstration and commercialization of an industrial cogeneration system. 3 refs., 13 figs.

  11. Method and apparatus for reducing cold-phase emissions by utilizing oxygen-enriched intake air

    DOEpatents

    Poola, Ramesh B.; Sekar, Ramanujam R.; Stork, Kevin C.

    1997-01-01

    An oxygen-enriched air intake control system for an internal combustion engine includes air directing apparatus to control the air flow into the intake of the engine. During normal operation of the engine, ambient air flowing from an air filter of the engine flows through the air directing apparatus into the intake of the engine. In order to decrease the amount of carbon monoxide (CO) and hydrocarbon (HC) emissions that tend to be produced by the engine during a short period of time after the engine is started, the air directing apparatus diverts for a short period of time following the start up of the engine at least a portion of the ambient air from the air filter through a secondary path. The secondary path includes a selectively permeable membrane through which the diverted portion of the ambient air flows. The selectively permeable membrane separates nitrogen and oxygen from the diverted air so that oxygen enriched air containing from about 23% to 25% oxygen by volume is supplied to the intake of the engine.

  12. Experimental study on improving cement quality with oxygen- enriched combustion technology

    NASA Astrophysics Data System (ADS)

    Liu, Y. Q.; Zhang, A. M.; Qing, S.; Li, F. S.; Yang, S. P.; Yang, Z. F.

    2015-12-01

    With the intensification of the global energy crisis, the production cost of enterprises is continuously increasing because of the rising fuel prices and high requirements for environmental protection. As result, energy savings and environmental protection are vital considerations for a variety of enterprises. As a practical energy-saving technology, oxygen- enriched combustion has played a major role in energy saving and emissions reduction as its application in industrial furnaces has been popularized in recent years. This experiment was conducted in a cement rotary kiln with a capacity of 4000 t/d in a factory in China. Based on measured data in the oxygen-enriched combustion experiment, we determined the patterns of variation in the main parameters of the cement rotary kiln under oxygen-enriched production conditions. The results provide important theoretical and practical base for the cement building materials industry in energy saving and emissions reduction.

  13. The balance model of oxygen enrichment of atmospheric air

    NASA Astrophysics Data System (ADS)

    Popov, Alexander

    2013-04-01

    The study of turnover of carbon and oxygen is an important line of scientific investigation. This line takes on special significance in conditions of soil degradation, which leads to the excess content of carbon dioxide and, as result, decrease of oxygen in the atmosphere. The aim of this article is a statement the balance model of oxygen enrichment of atmospheric air (ratio O/C) depending on consumption and assimilation by plants of dissolved organic matter (DOM) and the value of the oxidation-reduction potential (Eh). Basis of model was the following: green vascular plants are facultative heterotrophic organisms with symbiotic digestion and nutrition. According to the trophology viewpoint, the plant consumption of organic compounds broadens greatly a notion about the plant nutrition and ways of its regulation. In particular, beside the main known cycle of carbon: plant - litter - humus - carbon dioxide - plant, there is the second carbon cycle (turnover of organic compounds): plant - litter - humus - DOM - plant. The biogeochemical meaning of consumption of organic compounds by plants is that plants build the structural and functional blocks of biological macromolecules in their bodies. It provides receiving of a certain "energy payoff" by plants, which leads to increase of plant biomass by both an inclusion of allochthonous organic molecules in plant tissues, and positive effect of organic compounds on plant metabolic processes. One more of powerful ecological consequence of a heterotrophic nutrition of green plants is oxygen enrichment of atmospheric air. As the organic molecules in the second biological cycle of carbon are built in plants without considerable chemical change, the atmospheric air is enriched on that amount of oxygen, which would be required on oxidation of the organic molecules absorbed by plants, in result. It was accepted that: plant-soil system was climax, the plant community was grassy, initial contents of carbon in phytomass was accepted

  14. Application of oxygen-enriched combustion for locomotive diesel engines. Phase 1

    SciTech Connect

    Poola, R.B.; Sekar, R.R.; Assanis, D.N.

    1996-09-01

    A thermodynamic simulation is used to study the effects of oxygen-enriched intake air on the performance and nitrogen oxide (NO) emissions of a locomotive diesel engine. The parasitic power of the air separation membrane required to supply the oxygen-enriched air is also estimated. For a given constraint on peak cylinder pressure, the gross and net power outputs of an engine operating under different levels of oxygen enrichment are compared with those obtained when a high-boost turbocharged engine is used. A 4% increase in peak cylinder pressure can result in an increase in net engine power of approximately 13% when intake air with an oxygen content of 28% by volume is used and fuel injection timing is retarded by 4 degrees. When the engine is turbocharged to a higher inlet boost, the same increase in peak cylinder pressure improves power by only 4%. If part of the significantly higher exhaust enthalpies available as a result of oxygen enrichment are recovered, the power requirements of the air separator membrane can be met, resulting in substantial net power improvements. Oxygen enrichment reduces particulate and visible smoke emissions but increases NO emissions. However, a combination of retarded fuel injection timing and post-treatment of exhaust gases may be adequate to meet the locomotive diesel engine NO{sub x} standards. Exhaust gas after-treatment and heat recovery would be required to realize the full potential of oxygen enrichment. Economic analysis shows that oxygen-enrichment technology is economically feasible and provides high returns on investment. The study also indicates the strong influence of membrane parasitic requirements and exhaust energy recovery on economic benefits. To obtain an economic advantage while using a membrane with higher parasitic power requirements, it is necessary to recover a part of the exhaust energy.

  15. Sooting Limits Of Diffusion Flames With Oxygen-Enriched Air And Diluted Fuel

    NASA Technical Reports Server (NTRS)

    Sunderland, P. B.; Urban, D. L.; Stocker, D. P.; Chao, B. H.; Axelbaum, R. L.

    2003-01-01

    Oxygen-enhanced combustion permits certain benefits and flexibility that are not otherwise available in the design of practical combustors, as discussed by Baukal. The cost of pure and enriched oxygen has declined to the point that oxygen-enhanced combustion is preferable to combustion in air for many applications. Carbon sequestration is greatly facilitated by oxygen enrichment because nitrogen can be eliminated from the product stream. For example, when natural gas (or natural gas diluted with CO2) is burned in pure oxygen, the only significant products are water and CO2. Oxygen-enhanced combustion also has important implications for soot formation, as explored in this work. We propose that soot inception in nonpremixed flames requires a region where C/O ratio, temperature, and residence time are above certain critical values. Soot does not form at low temperatures, with the threshold in nonpremixed flames ranging from about 1250-1650 K, a temperature referred to here as the critical temperature for soot inception, Tc. Soot inception also can be suppressed when residence time is short (equivalently, when the strain rate in counterflow flames is high). Soot induction times of 0.8-15 ms were reported by Tesner and Shurupov for acetylene/nitrogen mixtures at 1473 K. Burner stabilized spherical microgravity flames are employed in this work for two main reasons. First, this configuration offers unrestricted control over convection direction. Second, in steady state these flames are strain-free and thus can yield intrinsic sooting limits in diffusion flames, similar to the way past work in premixed flames has provided intrinsic values of C/O ratio associated with soot inception limits.

  16. Simulation and experiment for oxygen-enriched combustion engine using liquid oxygen to solidify CO2

    NASA Astrophysics Data System (ADS)

    Liu, Yongfeng; Jia, Xiaoshe; Pei, Pucheng; Lu, Yong; Yi, Li; Shi, Yan

    2016-01-01

    For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation (EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.

  17. The effects of oxygen-enriched intake air on FFV exhaust emissions using M85

    SciTech Connect

    Poola, R.B.; Sekar, R.; Ng, H.K.; Baudino, J.H.; Colucci, C.P.

    1996-05-01

    This paper presents results of emission tests of a flexible fuel vehicle (FFV) powered by an SI engine, fueled by M85 (methanol), and supplied with oxygen-enriched intake air containing 21, 23, and 25 vol% O2. Engine-out total hydrocarbons (THCs) and unburned methanol were considerably reduced in the entire FTP cycle when the O2 content of the intake air was either 23 or 25%. However, CO emissions did not vary much, and NOx emissions were higher. HCHO emissions were reduced by 53% in bag 1, 84% in bag 2, and 59% in bag 3 of the FTP cycle with 25% oxygen-enriched intake air. During cold-phase FTP,reductions of 42% in THCs, 40% in unburned methanol, 60% in nonmethane hydrocarbons, and 45% in nonmethane organic gases (NMOGs) were observed with 25% enriched air; NO{sub x} emissions increased by 78%. Converter-out emissions were also reduced with enriched air but to a lesser degree. FFVs operating on M85 that use 25% enriched air during only the initial 127 s of cold-phase FTP or that use 23 or 25% enriched air during only cold-phase FTP can meet the reactivity-adjusted NMOG, CO, NO{sub x}, and HCHO emission standards of the transitional low-emission vehicle.

  18. Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine

    SciTech Connect

    Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J.

    1991-11-01

    The performance of a single-cylinder, direct-injection diesel engine was measured with intake oxygen levels of up to 35% and fuel water contents of up to 20%. Because a previous study indicated that the use of a less-expensive fuel would be more economical, two series of tests with No. 4 diesel fuel and No. 2 diesel fuel were conducted. To control the emissions of nitrogen oxides (NO{sub x}), water was introduced into the combustion process in the form of water-emulsified fuel, or the fuel injection timing was retarded. In the first series of tests, compressed oxygen was used; in the second series of tests, a hollow-tube membrane was used. Steady-state engine performance and emissions data were obtained. Test results indicated a large increase in engine power density, a slight improvement in thermal efficiency, and significant reductions in smoke and particulate-matter emissions. Although NO{sub x} emissions increased, they could be controlled by introducing water and retarding the injection timing. The results further indicated that thermal efficiency is slightly increased when moderately water-emulsified fuels are used, because a greater portion of the fuel energy is released earlier in the combustion process. Oxygen-enriched air reduced the ignition delay and caused the heat-release rate and cumulative heat-release rates to change measurably. Even at higher oxygen levels, NO{sub x} emissions decreased rapidly when the timing was retarded, and the amount of smoke and the level of particulate-matter emissions did not significantly increase. The single-cylinder engine tests confirmed the results of an earlier technical assessment and further indicated a need for a low-pressure-drop membrane specifically designed for oxygen enrichment. Extension data set indexed separately. 14 refs.

  19. Synthesis of silicalite-poly(furfuryl alcohol) composite membranes for oxygen enrichment from air

    PubMed Central

    2011-01-01

    Silicalite-poly(furfuryl alcohol) [PFA] composite membranes were prepared by solution casting of silicalite-furfuryl alcohol [FA] suspension on a porous polysulfone substrate and subsequent in situ polymerization of FA. X-ray diffraction, nitrogen sorption, thermogravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to characterize silicalite nanocrystals and silicalite-PFA composite membranes. The silicalite-PFA composite membrane with 20 wt.% silicalite loading exhibits good oxygen/nitrogen selectivity (4.15) and high oxygen permeability (1,132.6 Barrers) at 50°C. Silicalite-PFA composite membranes are promising for the production of oxygen-enriched air for various applications. PMID:22209012

  20. Oxygen enrichment of room air to improve well-being and productivity at high altitude.

    PubMed

    West, J B

    1999-01-01

    Increasingly, commercial activities, such as mines, and scientific facilities, such as telescopes, are being placed at very high altitudes, up to 5,000 m. Frequently workers commute to these locations from much lower altitudes, or even from sea level. In addition, large numbers of people permanently live and work at high altitudes. The hypoxia of high altitude impairs sleep quality, mental performance, productivity, and general well-being. Recently it has become feasible to raise the oxygen concentration of room air by injecting oxygen into the air conditioning. This is remarkably effective at reducing the equivalent altitude. For example, increasing the oxygen concentration by 1% (e.g., from 21% to 22%) reduces the equivalent altitude by about 300 m. In other words, a room at an altitude of 4,500 m containing 26% oxygen is effectively at an altitude of 3,000 m. Oxygen enrichment has now been tested in several studies and shown to improve sleep quality and cognitive function. The fire hazard is less than in air at sea level. This innovative technique promises to improve productivity and well-being at high altitude. PMID:10441257

  1. Characterization of single coal particle combustion within oxygen-enriched environments using high-speed OH-PLIF

    NASA Astrophysics Data System (ADS)

    Köser, J.; Becker, L. G.; Vorobiev, N.; Schiemann, M.; Scherer, V.; Böhm, B.; Dreizler, A.

    2015-12-01

    This work presents first-of-its-kind high-speed planar laser-induced fluorescence measurements of the hydroxyl radical in the boundary layer of single coal particles. Experiments were performed in a laminar flow reactor providing an oxygen-enriched exhaust gas environment at elevated temperatures. Single coal particles in a sieve fraction of 90-125 µm and a significant amount of volatiles (36 wt%) were injected along the burner's centerline. Coherent anti-Stokes Raman spectroscopy measurements were taken to characterize the gas-phase temperature. Time-resolved imaging of the OH distribution at 10 kHz allowed identifying reaction and post-flame zones and gave access to the temporal evolution of burning coal particles. During volatile combustion, a symmetric diffusion flame was observed around the particle starting from a distance of ~150 µm from the particle surface. For subsequent char combustion, this distance decreased and the highest OH signals appeared close to the particle surface.

  2. Development of Nanofiller-Modulated Polymeric Oxygen Enrichment Membranes for Reduction of Nitrogen Oxides in Coal Combustion

    SciTech Connect

    Jianzhong Lou; Shamsuddin Ilias

    2010-12-31

    North Carolina A&T State University in Greensboro, North Carolina, has undertaken this project to develop the knowledge and the material to improve the oxygen-enrichment polymer membrane, in order to provide high-grade oxygen-enriched streams for coal combustion and gasification applications. Both experimental and theoretical approaches were used in this project. The membranes evaluated thus far include single-walled carbon nano-tube, nano-fumed silica polydimethylsiloxane (PDMS), and zeolite-modulated polyimide membranes. To document the nanofiller-modulated polymer, molecular dynamics simulations have been conducted to calculate the theoretical oxygen molecular diffusion coefficient and nitrogen molecular coefficient inside single-walled carbon nano-tube PDMS membranes, in order to predict the effect of the nano-tubes on the gas-separation permeability. The team has performed permeation and diffusion experiments using polymers with nano-silica particles, nano-tubes, and zeolites as fillers; studied the influence of nano-fillers on the self diffusion, free volume, glass transition, oxygen diffusion and solubility, and perm-selectivity of oxygen in polymer membranes; developed molecular models of single-walled carbon nano-tube and nano-fumed silica PDMS membranes, and zeolites-modulated polyimide membranes. This project partially supported three graduate students (two finished degrees and one transferred to other institution). This project has resulted in two journal publications and additional publications will be prepared in the near future.

  3. Carbon dioxide remediation via oxygen-enriched combustion using dense ceramic membranes

    DOEpatents

    Balachandran, Uthamalingam; Bose, Arun C.; McIlvried, Howard G.

    2001-01-01

    A method of combusting pulverized coal by mixing the pulverized coal and an oxidant gas to provide a pulverized coal-oxidant gas mixture and contacting the pulverized coal-oxidant gas mixture with a flame sufficiently hot to combust the mixture. An oxygen-containing gas is passed in contact with a dense ceramic membrane of metal oxide material having electron conductivity and oxygen ion conductivity that is gas-impervious until the oxygen concentration on one side of the membrane is not less than about 30% by volume. An oxidant gas with an oxygen concentration of not less than about 30% by volume and a CO.sub.2 concentration of not less than about 30% by volume and pulverized coal is contacted with a flame sufficiently hot to combust the mixture to produce heat and a flue gas. One dense ceramic membrane disclosed is selected from the group consisting of materials having formulae SrCo.sub.0.8 Fe.sub.0.2 O.sub.x, SrCo.sub.0.5 FeO.sub.x and La.sub.0.2 Sr.sub.0.8 Co.sub.0.4 Fe.sub.0.6 O.sub.x.

  4. Demonstration of oxygen-enriched air staging at Owens-Brockway Glass Containers. Technical progress report, August 1, 1995--July 31, 1996

    SciTech Connect

    Rue, D.; Abbasi, H.

    1996-11-01

    The objective of the program is to demonstrate the use of a previously developed combustion modification technology to reduce NO, emissions from sideport regenerative container glass melters. This technology, known as oxygen-enriched air staging (OEAS), has been demonstrated, and is now being commercialized, for endport container glass furnaces. A 17-month development program has been established with specific objectives to: (1) acquire baseline operating data on the host sideport furnace in Vernon, California, (2) evaluate secondary oxidant injection strategies based on earlier endport furnace results and through modeling of a single port pair, (3) retrofit and test one port pair (the test furnace has six port pairs) with a flexible OEAS system, and select the optimal system configuration, (4) use the results from tests with one port pair to design, retrofit, and test OEAS on the entire furnace (six port pairs), and (5) analyze test results, prepare report, and finalize the business plan to commercialize OEAS for sideport furnaces. The host furnace for testing in this program is an Owens-Brockway 6-port pair sideport furnace in Vernon, California producing 325-ton/d of amber container glass. The baseline NO{sub x} level of this optimized furnace is about 4.0 lb/ton of glass. An anticipated NO{sub x}, reduction of 50% will lower the NO{sub x} production level to below 2 lb/ton. Secondary oxidant staging techniques being considered include oxygen-enriched ambient air staging (OEAS) and oxygen staging (OS).

  5. Demonstration of oxygen-enriched air staging at Owens-Brockway glass containers. Quarterly technical progress report, November 1, 1996--January 31, 1997

    SciTech Connect

    Rue, D.; Abbasi, H.

    1997-03-01

    The objective of the program is to demonstrate the use of a previously developed combustion modification technology to reduce NO, emissions from sideport regenerative container glass melters. This technology, known as oxygen-enriched air staging (OEAS), has been demonstrated, and is now being commercialized, for endport container glass furnaces. A 17-month development program has been established with specific objectives to: (1) acquire baseline operating data on the host sideport furnace in Vernon, California, (2) evaluate secondary oxidant injection strategies based on earlier endport furnace results and through modeling of a single port pair, (3) retrofit and test one port pair (the test furnace has six port pairs) with a flexible OEAS system, and select the optimal system configuration, (4) use the results from tests with one port pair to design, retrofit, and test OEAS on the entire furnace (six port pairs), and (5) analyze test results, prepare report, and finalize the business plan to commercialize OEAS for sideport furnaces. The host furnace for testing in this program is an Owens-Brockway 6-port pair sideport furnace in Vernon, California producing 325-ton/d of amber container glass. The baseline NO{sub x} level of this optimized furnace is about 4.0 lb/ton of glass. An anticipated NO{sub x}, reduction of 50% will lower the NO{sub x} production level to below 2 lb/ton. Secondary oxidant staging techniques being considered include oxygen-enriched ambient air staging (OEAS) and oxygen staging (OS).

  6. Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine. Volume 1, Concept evaluation

    SciTech Connect

    Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J.

    1991-11-01

    The performance of a single-cylinder, direct-injection diesel engine was measured with intake oxygen levels of up to 35% and fuel water contents of up to 20%. Because a previous study indicated that the use of a less-expensive fuel would be more economical, two series of tests with No. 4 diesel fuel and No. 2 diesel fuel were conducted. To control the emissions of nitrogen oxides (NO{sub x}), water was introduced into the combustion process in the form of water-emulsified fuel, or the fuel injection timing was retarded. In the first series of tests, compressed oxygen was used; in the second series of tests, a hollow-tube membrane was used. Steady-state engine performance and emissions data were obtained. Test results indicated a large increase in engine power density, a slight improvement in thermal efficiency, and significant reductions in smoke and particulate-matter emissions. Although NO{sub x} emissions increased, they could be controlled by introducing water and retarding the injection timing. The results further indicated that thermal efficiency is slightly increased when moderately water-emulsified fuels are used, because a greater portion of the fuel energy is released earlier in the combustion process. Oxygen-enriched air reduced the ignition delay and caused the heat-release rate and cumulative heat-release rates to change measurably. Even at higher oxygen levels, NO{sub x} emissions decreased rapidly when the timing was retarded, and the amount of smoke and the level of particulate-matter emissions did not significantly increase. The single-cylinder engine tests confirmed the results of an earlier technical assessment and further indicated a need for a low-pressure-drop membrane specifically designed for oxygen enrichment. Extension data set indexed separately. 14 refs.

  7. High cell density cultivation of Pseudomonas putida KT2440 using glucose without the need for oxygen enriched air supply.

    PubMed

    Davis, Reeta; Duane, Gearoid; Kenny, Shane T; Cerrone, Federico; Guzik, Maciej W; Babu, Ramesh P; Casey, Eoin; O'Connor, Kevin E

    2015-04-01

    High Cell Density (HCD) cultivation of bacteria is essential for the majority of industrial processes to achieve high volumetric productivity (g L(-1) h(-1) ) of a bioproduct of interest. This study developed a fed batch bioprocess using glucose as sole carbon and energy source for the HCD of the well described biocatalyst Pseudomonas putida KT2440 without the supply of oxygen enriched air. Growth kinetics data from batch fermentations were used for building a bioprocess model and designing feeding strategies. An exponential followed by linearly increasing feeding strategy of glucose was found to be effective in maintaining biomass productivity while also delaying the onset of dissolved oxygen (supplied via compressed air) limitation. A final cell dry weight (CDW) of 102 g L(-1) was achieved in 33 h with a biomass productivity of 3.1 g L(-1) h(-1) which are the highest ever reported values for P. putida strains using glucose without the supply of pure oxygen or oxygen enriched air. The usefulness of the biomass as a biocatalyst was demonstrated through the production of the biodegradable polymer polyhydroxyalkanoate (PHA). When nonanoic acid (NA) was supplied to the glucose grown cells of P. putida KT2440, it accumulated 32% of CDW as PHA in 11 h (2.85 g L(-1) h(-1) ) resulting in a total of 0.56 kg of PHA in 18 L with a yield of 0.56 g PHA g NA(-1) . PMID:25311981

  8. MHD performance calculations with oxygen enrichment

    NASA Technical Reports Server (NTRS)

    Pian, C. C. P.; Staiger, P. J.; Seikel, G. R.

    1979-01-01

    The impact of oxygen enrichment of the combustion air on the generator and overall plant performance was studied for the ECAS-scale MHD/steam plants. A channel optimization technique is described and the results of generator performance calculations using this technique are presented. Performance maps were generated to assess the impact of various generator parameters. Directly and separately preheated plant performance with varying O2 enrichment was calculated. The optimal level of enrichment was a function of plant type and preheat temperature. The sensitivity of overall plant performance to critical channel assumptions and oxygen plant performance characteristics was also examined.

  9. Demonstration of cost-effective NO{sub x} reduction on a regenerative sideport glass furnace using oxygen-enriched air staging

    SciTech Connect

    Mohr, P.; Neff, D.; Rue, D.

    1996-12-31

    The Gas Research Institute (GRI), the U.S. Department of Energy (DOE), and the Southern California Gas Company (SoCal) have joined with the development team of the Institute of Gas Technology (IGT), Combustion Tec, Inc. (CTI), and Air Products and Chemicals, Inc. (APCI) and provided support for extension of the oxygen-enriched air staging (OEAS) NO{sub x} control technology to natural gas-fired sideport regenerative glass melters. In previous demonstrations, the OEAS technology has successfully reduced NO{sub x} emissions by more than 50% on natural gas-fired endport regenerative glass melters without any adverse impacts on furnace performance or glass quality. In the current program, Owens-Brockway (OB) provided operations expertise and a 6 port pair, sideport furnace for field evaluation tests of OEAS. Background and initial test results for a single port pair and the complete furnace are presented along with CFD modeling results for OEAS on a single port pair of the sideport furnace. Modeling results confirm the capacity of OEAS to provide significant NO{sub x} reduction and CO burnout while maintaining or increasing thermal efficiency and furnace production rate.

  10. Novel Membranes and Processes for Oxygen Enrichment

    SciTech Connect

    Lin, Haiqing

    2011-11-15

    The overall goal of this project is to develop a membrane process that produces air containing 25-35% oxygen, at a cost of $25-40/ton of equivalent pure oxygen (EPO2). Oxygen-enriched air at such a low cost will allow existing air-fueled furnaces to be converted economically to oxygen-enriched furnaces, which in turn will improve the economic and energy efficiency of combustion processes significantly, and reduce the cost of CO{sub 2} capture and sequestration from flue gases throughout the U.S. manufacturing industries. During the 12-month Concept Definition project: We identified a series of perfluoropolymers (PFPs) with promising oxygen/nitrogen separation properties, which were successfully made into thin film composite membranes. The membranes showed oxygen permeance as high as 1,200 gpu and oxygen/nitrogen selectivity of 3.0, and the permeance and selectivity were stable over the time period tested (60 days). We successfully scaled up the production of high-flux PFP-based membranes, using MTR's commercial coaters. Two bench-scale spiral-wound modules with countercurrent designs were made and parametric tests were performed to understand the effect of feed flow rate and pressure, permeate pressure and sweep flow rate on the membrane module separation properties. At various operating conditions that modeled potential industrial operating conditions, the module separation properties were similar to the pure-gas separation properties in the membrane stamps. We also identified and synthesized new polymers [including polymers of intrinsic microporosity (PIMs) and polyimides] with higher oxygen/nitrogen selectivity (3.5-5.0) than the PFPs, and made these polymers into thin film composite membranes. However, these membranes were susceptible to severe aging; pure-gas permeance decreased nearly six-fold within two weeks, making them impractical for industrial applications of oxygen enrichment. We tested the effect of oxygen-enriched air on NO{sub x} emissions using a

  11. Efficiency evaluation of oxygen enrichment in energy conversion processes

    SciTech Connect

    Bomelburg, H.J.

    1983-12-01

    The extent to which energy conversion efficiencies can be increased by using oxygen or oxygen-enriched air for combustion was studied. Combustion of most fuels with oxygen instead of air was found to have five advantages: increases combustion temperature and efficiency, improves heat transfer at high temperatures, reduces nitrous oxide emissions, permits a high ration of exhaust gas recirculation and allows combustion of certain materials not combustible in air. The same advantages, although to a lesser degree, are apparent with oxygen-enriched air. The cost-effectiveness of the process must necessarily be improved by about 10% when using oxygen instead of air before such use could become justifiable on purely economic terms. Although such a modest increase appears to be attainable in real situations, this study ascertained that it is not possible to generally assess the economic gains. Rather, each case requires its own evaluation. For certain processes industry has already proven that the use of oxygen leads to more efficient plant operation. Several ideas for essentially new applications are described. Specifically, when oxygen is used with exhaust gas recirculation in external or internal combustion engines. It appears also that the advantages of pulse combustion can be amplified further if oxygen is used. When burning wet fuels with oxygen, direct steam generation becomes possible. Oxygen combustion could also improve processes for in situ gasification of coals, oil shales, peats, and other wet fuels. Enhanced oil recovery by fire flooding methods might also become more effective if oxygen is used. The cold energy contained in liquid oxygen can be substantially recovered in the low end of certain thermodynamic cycles. Further efforts to develop certain schemes for using oxygen for combustion appear to be justified from both the technical and economic viewpoints.

  12. Variable oxygen/nitrogen enriched intake air system for internal combustion engine applications

    DOEpatents

    Poola, Ramesh B.; Sekar, Ramanujam R.; Cole, Roger L.

    1997-01-01

    An air supply control system for selectively supplying ambient air, oxygen enriched air and nitrogen enriched air to an intake of an internal combustion engine includes an air mixing chamber that is in fluid communication with the air intake. At least a portion of the ambient air flowing to the mixing chamber is selectively diverted through a secondary path that includes a selectively permeable air separating membrane device due a differential pressure established across the air separating membrane. The permeable membrane device separates a portion of the nitrogen in the ambient air so that oxygen enriched air (permeate) and nitrogen enriched air (retentate) are produced. The oxygen enriched air and the nitrogen enriched air can be selectively supplied to the mixing chamber or expelled to atmosphere. Alternatively, a portion of the nitrogen enriched air can be supplied through another control valve to a monatomic-nitrogen plasma generator device so that atomic nitrogen produced from the nitrogen enriched air can be then injected into the exhaust of the engine. The oxygen enriched air or the nitrogen enriched air becomes mixed with the ambient air in the mixing chamber and then the mixed air is supplied to the intake of the engine. As a result, the air being supplied to the intake of the engine can be regulated with respect to the concentration of oxygen and/or nitrogen.

  13. Test Operation of Oxygen-Enriched Incinerator for Wastes From Nuclear Fuel Fabrication Facility

    SciTech Connect

    Kim, J.-G.; Yang, H.cC.; Park, G.-I.; Kim, I.-T.; Kim, J.-K.

    2002-02-26

    The oxygen-enriched combustion concept, which can minimize off-gas production, has been applied to the incineration of combustible uranium-containing wastes from a nuclear fuel fabrication facility. A simulation for oxygen combustion shows the off-gas production can be reduced by a factor of 6.7 theoretically, compared with conventional air combustion. The laboratory-scale oxygen enriched incineration (OEI) process with a thermal capacity of 350 MJ/h is composed of an oxygen feeding and control system, a combustion chamber, a quencher, a ceramic filter, an induced draft fan, a condenser, a stack, an off-gas recycle path, and a measurement and control system. Test burning with cleaning paper and office paper in this OEI process shows that the thermal capacity is about 320 MJ/h, 90 % of design value and the off-gas reduces by a factor of 3.5, compared with air combustion. The CO concentration for oxygen combustion is lower than that of air combustion, while the O2 concentration in off-gas is kept above 25 vol % for a simple incineration process without any grate. The NOx concentration in an off-gas stream does not reduce significantly due to air incoming by leakage, and the volume and weight reduction factors are not changed significantly, which suggests a need for an improvement in sealing.

  14. Waste to energy operability enhancement under waste uncertainty via oxygen enrichment.

    PubMed

    Tsiliyannis, Christos Aristeides

    2014-08-19

    Waste to energy (WTE) performance is evaluated by maximization of electrical energy production and throughput, while maintaining low operational costs and complying with emission limits. Uncertainty in the quantities, composition and heating values of received wastes, pose severe operability problems and impair performance and emissions. The present work demonstrates and quantifies the possibility of improving WTE efficiency under feedstock uncertainty via oxygen enrichment of the combustion air. Acting essentially as a nitrogen depletion mechanism, oxygen enrichment has reverse effects compared to excess air (EA); synergistic use provides extended capabilities for performance improvement, without impairing final emissions, while satisfying capacity constraints. Increased oxygen enrichment is required at higher EA to maintain temperature. Lower charging rates of rich wastes (plastics, paper, etc.) or diminishing heating values, require higher oxygen enrichment or lower EA. The opposite holds for lower charging rates of poor wastes (biodegradables, biosludge, inerts, etc.) or rising heating values. The results establish the possibility of nominal designs to respond to feedstock variations and may be useful for low range excess air operation (low cost) or adiabatic operation (high EA, combustor temperature controlled by large fluegas volumes). The vector formulation facilitates digital coding for applications featuring multiple waste mixture variability. A 700000 tpa WTE facility in Athens, now under public-private-partnership contract tender is investigated. PMID:25036380

  15. Oxygen-enriched diesel engine performance: A comparison of analytical and experimental results

    SciTech Connect

    Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. ); Assanis, D.N. ); Schaus, J.E. )

    1990-01-01

    Use of oxygen-enriched combustion air in diesel engines can lead to significant improvements in power density, as well as reductions in particulate emissions, but at the expense of higher NO{sub x} emissions. Oxygen enrichment would also lead to lower ignition delays and the opportunity to burn lower grade fuels. Analytical and experimental studies are being conducted in parallel to establish the optimal combination of oxygen level and diesel fuel properties. In this paper, cylinder pressure data acquired on a single-cylinder engine are used to generate heat release rates for operation under various oxygen contents. These derived heat release rates are in turn used to improve the combustion correlation -- and thus the prediction capability -- of the simulation code. It is shown that simulated and measured cylinder pressures and other performance parameters are in good agreement. The improved simulation can provide sufficiently accurate predictions of trends and magnitudes to be useful in parametric studies assessing the effects of oxygen enrichment and water injection on diesel engine performance. Measured ignition delays, NO{sub x} emissions, and particulate emissions are also compared with previously published data. The measured ignition delays are slightly lower than previously reported. Particulate emissions measured in this series of tests are significantly lower than previously reported. 14 refs., 10 figs., 1 tab.

  16. Taguchi methods applied to oxygen-enriched diesel engine experiments

    SciTech Connect

    Marr, W.W.; Sekar, R.R.; Cole, R.L.; Marciniak, T.J. ); Longman, D.E. )

    1992-01-01

    This paper describes a test series conducted on a six-cylinder diesel engine to study the impacts of controlled factors (i.e., oxygen content of the combustion air, water content of the fuel, fuel rate, and fuel-injection timing) on engine emissions using Taguchi methods. Three levels of each factor were used in the tests. Only the main effects of the factors were examined; no attempt was made to analyze the interactions among the factors. It was found that, as in the case of the single-cylinder engine tests, oxygen in the combustion air was very effective in reducing particulate and smoke emissions. Increases in NO[sub x] due to the oxygen enrichment observed in the single-cylinder tests also occurred in the present six-cylinder tests. Water in the emulsified fuel was found to be much less effective in decreasing NO[sub x] emissions for the six-cylinder engine than it was for the single-cylinder engine.

  17. Taguchi methods applied to oxygen-enriched diesel engine experiments

    SciTech Connect

    Marr, W.W.; Sekar, R.R.; Cole, R.L.; Marciniak, T.J.; Longman, D.E.

    1992-12-01

    This paper describes a test series conducted on a six-cylinder diesel engine to study the impacts of controlled factors (i.e., oxygen content of the combustion air, water content of the fuel, fuel rate, and fuel-injection timing) on engine emissions using Taguchi methods. Three levels of each factor were used in the tests. Only the main effects of the factors were examined; no attempt was made to analyze the interactions among the factors. It was found that, as in the case of the single-cylinder engine tests, oxygen in the combustion air was very effective in reducing particulate and smoke emissions. Increases in NO{sub x} due to the oxygen enrichment observed in the single-cylinder tests also occurred in the present six-cylinder tests. Water in the emulsified fuel was found to be much less effective in decreasing NO{sub x} emissions for the six-cylinder engine than it was for the single-cylinder engine.

  18. An oxygen enrichment device for lowlanders ascending to high altitude

    PubMed Central

    2013-01-01

    Background When ascending to the high altitude, people living in low altitude areas will suffer from acute mountain sickness. The aim of this study is to test the hypothesis that whether an oxygen concentration membrane can be made and used to construct a new portable oxygen enrichment device for individuals in acute exposure to the high altitude. Methods The membrane was fabricated using vinylsiloxane rubber, polyphenylene oxide hydrogen silicone polymers, chloroplatinic acid and isopropyl alcohol. The membrane was assembled in a frame and the performance was tested in terms of concentration of oxygen, flow rate of oxygen enriched air, pressure ratio across the membrane and ambient temperature. Furthermore, the oxygen concentration device was constructed using the membrane, a DC fan, vacuum pump and gas buffer. A nonrandomized preliminary field test was conducted, in which eight healthy male subjects were flown to Tibet (Lhasa, 3,700 m). First, subjects wore the oxygen enrichment device and performed an incremental exercise on cycle ergometer. The test included heart rate (HR), saturation of peripheral oxygen (SpO2) and physical work capacity (PWC). Then, after a rest period of 4 hours, the experimental protocol was repeated without oxygen enrichment device. Results The testing showed that the membrane could increase the oxygen concentration by up to 30%. Simulation test indicated that although the performance of the oxygen enrichment device decreased with altitudes, the oxygen concentration could still maintain 28% with flow rate of enriched air 110 cm3/s at 5000 m. The field test showed that higher SpO2, lower HR, and better PWC (measured by the PWC-170) were observed from all the subjects using oxygen enrichment device compared with non-using (P < 0.01). Conclusions We concluded that the new portable oxygen enrichment device would be effective in improving exercise performance when ascending to the high altitude. PMID:24103365

  19. Diesel engine experiments with oxygen enrichment, water addition and lower-grade fuel

    SciTech Connect

    Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. ); Schaus, J.E. )

    1990-01-01

    The concept of oxygen enriched air applied to reciprocating engines is getting renewed attention in the context of the progress made in the enrichment methods and the tougher emissions regulations imposed on diesel and gasoline engines. An experimental project was completed in which a direct injection diesel engine was tested with intake oxygen levels of 21% -- 35%. Since an earlier study indicated that it is necessary to use a cheaper fuel to make the concept economically attractive, a less refined fuel was included in the test series. Since a major objection to the use of oxygen enriched combustion air had been the increase in NO{sub x} emissions, a method must be found to reduce NO{sub x}. Introduction of water into the engine combustion process was included in the tests for this purpose. Fuel emulsification with water was the means used here even though other methods could also be used. The teat data indicated a large increase in engine power density, slight improvement in thermal efficiency, significant reductions in smoke and particulate emissions and NO{sub x} emissions controllable with the addition of water. 15 refs., 10 figs., 2 tabs.

  20. AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

    EPA Science Inventory

    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

  1. Demonstration of oxygen-enriched air staging at Owens-Brockway glass containers. Final technical report for the period April 1, 1995--February 28, 1997

    SciTech Connect

    Rue, D.; Abbasi, H.

    1997-10-01

    The overall objective of this program was to demonstrate the use of a previously developed combustion modification technology to reduce NO{sub x} emissions from sideport regenerative container glass melters. Specific objectives were to: acquire baseline operating data on the host sideport furnace, evaluate secondary oxidant injection strategies based on earlier endport furnace results and through modeling of a single port pair, retrofit and test one port pair (the test furnace has six port pairs) with a flexible OEAS system, and select the optimal system configuration, use the results from tests with one port pair to design, retrofit, and test OEAS on the entire furnace (six port pairs), and analyze test results, prepare report, and finalize the business plan to commercialize OEAS for sideport furnaces.

  2. Demonstration of oxygen-enriched air staging at Owens-Brockway glass containers. Quarterly report. Feb. 1, 1996--Apr. 30, 1996

    SciTech Connect

    1996-07-01

    Objective is to demonstrate use of a previously developed combustion modification technology to reduce NO{sub x} emissions from sideport regenerative container glass melters. Host furnace is an Owens- Brockway 6-port pair sideport furnace in Vernon CA producing 325- ton/d of amber container glass. Baseline NO{sub x} level is 4.0 lb/ton glass; an anticipated NO{sub x} reduction of 50% would lower this to below 2 lb/ton. With the OEAS operating on only one of the 6 ports, an overall NO{sub x} reduction of 8-10% was obtained, suggesting that an overall furnance NO{sub x} reduction of 50% can be achieved.

  3. Evaluation of oxygen-enrichment system for alternative fuel vehicles

    SciTech Connect

    Poola, R.B.; Sekar, R.R.; Ng, H.K.

    1995-12-01

    This report presents results on the reduction in exhaust emissions achieved by using oxygen-enriched intake air on a flexible fuel vehicle (FFV) that used Indolene and M85 as test fuels. The standard federal test procedure (FTP) and the US Environmental Protection Agency`s (EPA`s) off-cycle (REP05) test were followed. The report also provides a review of literature on the oxygen membrane device and design considerations. It presents information on the sources and contributions of cold-phase emissions to the overall exhaust emissions from light-duty vehicles (LDVs) and on the various emission standards and present-day control technologies under consideration. The effects of oxygen-enriched intake air on FTP and off-cycle emissions are discussed on the basis of test results. Conclusions are drawn from the results and discussion, and different approaches for the practical application of this technology in LDVs are recommended.

  4. Bus application of oxygen-enrichment technology and diesel-electric hybrid systems

    SciTech Connect

    Sekar, R.R.; Marr, W.W.

    1993-10-01

    The amendments to the Clean Air Act (CAA) mandate very strict limits on particulate, smoke, and other emissions from city buses. The use of alternative fuels, such as compressed natural gas (CNG) or methanol, can help transit operators, such as the Chicago Transit Authority (CTA), meet the mandated limits. However, the capital investment needed to convert the fueling infrastructure and buses is large, as is the expense of training personnel. If a {open_quotes}clean diesel{close_quotes} bus can be implemented with the help of oxygen-enrichment technology or a diesel-electric hybrid system, this large investment could be postponed for many years. The Regional Transportation Authority (RTA) initiated this project to evaluate the possibility of applying these technologies to CTA buses. Argonne National Laboratory (ANL) conducted a limited number of engine tests and computer analyses and concluded that both concepts are practical and will help in a {open_quotes}clean diesel{close_quotes} bus that can meet the mandated limits of the CAA amendments. The oxygen enrichment of combustion air depends on the availability of a compact and economical membrane separator. Because the technology for this critical component is still under development, it is recommended that an actual bus demonstration be delayed until prototype membranes are available. The hybrid propulsion system is ready for the demonstration phase, and it is recommended that the CTA and RTA commence planning for a bus demonstration.

  5. A new test method for the assessment of the arc tracking properties of wire insulation in air, oxygen enriched atmospheres and vacuum

    NASA Technical Reports Server (NTRS)

    Koenig, Dieter

    1994-01-01

    Development of a new test method suitable for the assessment of the resistance of aerospace cables to arc tracking for different specific environmental and network conditions of spacecraft is given in view-graph format. The equipment can be easily adapted for tests at different realistic electrical network conditions incorporating circuit protection and the test system works equally well whatever the test atmosphere. Test results confirm that pure Kapton insulated wire has bad arcing characteristics and ETFE insulated wire is considerably better in air. For certain wires, arc tracking effects are increased at higher oxygen concentrations and significantly increased under vacuum. All tests on different cable insulation materials and in different environments, including enriched oxygen atmospheres, resulted in a more or less rapid extinguishing of all high temperature effects at the beginning of the post-test phase. In no case was a self-maintained fire initiated by the arc.

  6. Fire extinguishment in oxygen enriched atmospheres

    NASA Technical Reports Server (NTRS)

    Robertson, A. F.; Rappaport, M. W.

    1973-01-01

    Current state-of-the-art of fire suppression and extinguishment techniques in oxygen enriched atmosphere is reviewed. Four classes of extinguishment action are considered: cooling, separation of reactants, dilution or removal of fuel, and use of chemically reactive agents. Current practice seems to show preference for very fast acting water spray applications to all interior surfaces of earth-based chambers. In space, reliance has been placed on fire prevention methods through the removal of ignition sources and use of nonflammable materials. Recommendations are made for further work related to fire suppression and extinguishment in oxygen enriched atmospheres, and an extensive bibliography is appended.

  7. Gas turbine combustion chamber with air scoops

    SciTech Connect

    Mumford, S.E.; Smed, J.P.

    1989-12-19

    This patent describes a gas turbine combustion chamber. It comprises: means for admission of fuel to the upstream end thereof and discharge of hot gases from the downstream end thereof, and a combustion chamber wall, having an outer surface, with apertures therethrough, and air scoops provided through the apertures to direct air into the combustion chamber.

  8. Oxygen-enriched coincineration of MSW and sewage sludge: Final report

    SciTech Connect

    1994-01-01

    Federal regulations banning ocean dumping of sewage sludge coupled with stricter regulations on the disposal of sewage sludge in landfills have forced municipalities, especially those in the northeast United States, to consider alternate methods for disposal of this solid waste. Coincineration of municipal solid waste (MSW) and sludge has proven to be economically attractive for both Europe and Japan, but has not yet proven to be a viable sludge disposal technology in the United States because of a history of operational problems in existing facilities. The most prevalent problem in coincinerating MSW and a dewatered sewage sludge (15 to 25% solids) is incomplete sludge combustion. Incomplete sludge combustion is primarily a function of sludge particle size, occurring when the surface of the sludge particle dries and hardens, while the inner mass is unaffected. This phenomenon is commonly referred to in the industry as the {open_quotes}hamburger effect.{close_quotes} In an effort to promote technology development in this area, Air Products and Chemicals, Inc. teamed with the US Department of Energy (DOE) through the National Renewable Energy Laboratory (NREL) to evaluate a new process being developed for the disposal of a dewatered sewage sludge, {open_quotes}Oxygen-Enriched Coincineration of MSW and Sewage Sludge.{close_quotes} This report provides a comprehensive summary of the pilot demonstration test program for oxygen-enriched coincineration of MSW and sewage sludge. This report describes the pilot test facility, instrumentation, and methods of data collection and data analyses; describes how the tests were executed; and discusses the test results. Recommendations for the future development of this technology in the current marketplace are also provided.

  9. Properties of air and combustion products of fuel with air

    NASA Technical Reports Server (NTRS)

    Poferl, D. J.; Svehla, R. A.

    1975-01-01

    Thermodynamic and transport properties have been calculated for air, the combustion products of natural gas and air, and combustion products of ASTM-A-1 jet fuel and air. Properties calculated include: ratio of specific heats, molecular weight, viscosity, specific heat, thermal conductivity, Prandtl number, and enthalpy.

  10. Turbulent Methane-Air Combustion

    NASA Technical Reports Server (NTRS)

    Yaboah, Yaw D.; Njokwe, Anny; James, LaShanda

    1996-01-01

    This study is aimed at enhancing the understanding of turbulent premixed methane-air combustion. Such understanding is essential since: (1) many industries are now pursuing lighter hydrocarbon alternative fuels and the use of premixed flames to reduce pollutant emissions, and (2) the characteristic dimensions and flow rates of most industrial combustors are often large for flows to be turbulent. The specific objectives of the study are: (1) to establish the effects of process variables (e.g., flow rate, fuel/air ratio, chlorinated hydro-carbons, and pressure) on the emissions and flow structure (velocity distribution, streamlines, vorticity and flame shape), and (2) to develop a mechanistic model to explain the observed trends. This includes the acquisition of Dantec FlowMap Particle Image Velocimeter. The design and fabrication of the premixed burner has also been completed. The study is now at the stage of testing of equipment and analytical instruments. The presentation will give details on the tasks completed and on the current and future plans. The project is progressing well and all activities are on schedule. The outlook for the success of the project is bright.

  11. Dissolution of oxygen-enriched Zircaloy-2

    NASA Astrophysics Data System (ADS)

    Oskarsson, M.; Ahlberg, E.; Pettersson, K.

    2001-10-01

    When metal is removed from oxidised Zircaloy specimens in order to study the morphology of the oxide at the metal-oxide interface needle-like features are frequently observed. Since similar features are not observed in cross-section TEM examinations it has been questioned whether or not the needles are a result of the dissolution process. In particular it has been proposed that reprecipitation of oxide may take place when the metal is enriched with oxygen. In the present work oxygen-enriched Zircaloy has been dissolved and the resulting structures examined. The results indicate that the needles are in fact artefacts of the specimen preparation procedure. However, there are no significant differences between oxygen-enriched and normal Zircaloy below an oxide layer grown in steam at about 400 °C. In view of the differences between the needle structure observed after metal removal with bromine or by electropolishing and removal by HF-HNO 3 pickling solution it is speculated that the needles consist of a hydrous zirconium oxide which is unstable in the pickling solution.

  12. Low NOx combustion using cogenerated oxygen and nitrogen streams

    DOEpatents

    Kobayashi, Hisashi; Bool, Lawrence E.; Snyder, William J.

    2009-02-03

    Combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.

  13. Combustion air can become a problem

    SciTech Connect

    Not Available

    1982-01-01

    Improper air combustion in a well-sealed house can result in an inadequate supply of oxygen and dangerous or fatal carbon monoxide levels. An opening for outside combustion air can prevent ''air starvation'' and if properly located and sized, can save energy by improving the furnace efficiency. This opening will also keep cold outside air from entering when the furnace is not in use, and prevent a blockage when in use, if properly designed. Possible indicators of inadequate combustion air in oil-fueled homes are: chimney smoke is black-colored, fuel smell in house, soot accumulation, popping, banging, or late ignition in the furnace. In natural gas-fueled homes: excessive moisture collecting on windows and walls, frequent headaches, burning feeling in nose and eyes. (JMT)

  14. A simplified method for determining heat of combustion of natural gas

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Chegini, Hoshang; Mall, Gerald H.

    1987-01-01

    A simplified technique for determination of the heat of combustion of natural gas has been developed. It is a variation of the previously developed technique wherein the carrier air, in which the test sample was burnt, was oxygen enriched to adjust the mole fraction of oxygen in the combustion product gases up to that in the carrier air. The new technique eliminates the need for oxygen enrichment of the experimental mixtures and natural gas samples and has been found to predict their heats of combustion to an uncertainty of the order of 1 percent.

  15. Combustion engine. [for air pollution control

    NASA Technical Reports Server (NTRS)

    Houseman, J. (Inventor)

    1977-01-01

    An arrangement for an internal combustion engine is provided in which one or more of the cylinders of the engine are used for generating hydrogen rich gases from hydrocarbon fuels, which gases are then mixed with air and injected into the remaining cylinders to be used as fuel. When heavy load conditions are encountered, hydrocarbon fuel may be mixed with the hydrogen rich gases and air and the mixture is then injected into the remaining cylinders as fuel.

  16. NOX CONTROL BY COMBUSTION MODIFICATION (AIR POLLUTION TECHNOLOGY BRANCH, AIR POLLUTION PREVENTION AND CONTROL DIVISION, NRMRL)

    EPA Science Inventory

    NRMRL's Air Pollution Prevention and Control Division's Air Pollution Technology Branch has performed research and developed technologies for NOx reduction via combustion modification. Techniques such as low-excess air firing, staged combustion, flue gas recirculation, low NOx bu...

  17. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air...

  18. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air...

  19. The optimization air separation plants for combined cycle MHD-power plant applications

    NASA Technical Reports Server (NTRS)

    Juhasz, A. J.; Springmann, H.; Greenberg, R.

    1980-01-01

    Some of the design approaches being employed during a current supported study directed at developing an improved air separation process for the production of oxygen enriched air for magnetohydrodynamics (MHD) combustion are outlined. The ultimate objective is to arrive at conceptual designs of air separation plants, optimized for minimum specific power consumption and capital investment costs, for integration with MHD combined cycle power plants.

  20. Supplemental air valve for internal combustion engine

    SciTech Connect

    Pankow, C.W.

    1987-12-29

    A valve for attachment in the PCV system of an internal combustion engine for regulating the admission of supplemental air to the crank case blow-by return, comprising: (a) a valve body defining a bore, the body having an inlet and an outlet connection defining a passageway through the valve for the blow-by return, the body further defining a port for air; (b) a valve member reciprocal within the bore having a piston member dividing at least a portion of the bore into two pressure chambers, the pressure chambers having means for connection of each to a source of engine vacuum; (c) the valve member being shiftable from and open position permitting air to enter through the port to the passageway and having a closed position blocking admission of air through the port to the passageway; and (d) resilient means normally urging the valve body to the closed position, the resilient means being selectively adjustable to provide a predetermined biasing force whereby the piston is shiftable to the open position in response to changes in engine vacuum to admit supplemental air to the engine.

  1. Development of materials screening tests for oxygen-enriched environments

    NASA Technical Reports Server (NTRS)

    Johnston, R. L.; Pippen, D. L.

    1971-01-01

    The criteria governing materials to be used in an oxygen enriched atmosphere and tests to determine suitability for fireproof considerations in spacecraft design are discussed. The nine tests applied to materials before acceptance in spacecraft construction are presented. The application of the standard tests to determine ranking of materials is included.

  2. Multi-stage combustion using nitrogen-enriched air

    DOEpatents

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14

    Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

  3. Emission Controls Using Different Temperatures of Combustion Air

    PubMed Central

    Holubčík, Michal; Papučík, Štefan

    2014-01-01

    The effort of many manufacturers of heat sources is to achieve the maximum efficiency of energy transformation chemically bound in the fuel to heat. Therefore, it is necessary to streamline the combustion process and minimize the formation of emission during combustion. The paper presents an analysis of the combustion air temperature to the heat performance and emission parameters of burning biomass. In the second part of the paper the impact of different dendromass on formation of emissions in small heat source is evaluated. The measured results show that the regulation of the temperature of the combustion air has an effect on concentration of emissions from the combustion of biomass. PMID:24971376

  4. Air quality effects of residential wood combustion

    SciTech Connect

    Cannon, J.A.

    1984-09-01

    In the mid 1970s the air quality in Missoula, Montana began to deteriorate due to pollution from wood-burning stoves. By 1980, 12,000 households were heating their homes with wood to some degree. Consequently, particulate concentrations rose sharply, with concentrations of over 500 ..mu..g/m/sup 3/ on many days. Because of health concerns, the Montana Department of Health and Environmental Sciences carried out an air pollution study. According to the data studied, airborne particulates appeared to be impairing the pulmonary function of children and older individuals with obstructive pulmonary disease. The correlation between human health effects and wood stove emissions was even more serious because of the size of the particulates; i.e., less than ten microns in diameter. A number of communities across the country have instituted voluntary and/or mandatory restrictions on local wood-burning. EPA has been involved in a number of activities that support the efforts of any community that thinks it has a potential air quality problem caused by residential wood combustion. The agency has also funded research on mutagenic and carcinogenic effects of wood smoke emission on mamallian cells and rodents.

  5. Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C; Hibbard, Robert R

    1957-01-01

    Basic combustion research is collected, collated, and interpreted as it applies to flight propulsion. The following fundamental processes are treated in separate chapters: atomization and evaporation of liquid fuels, flow and mixing processes in combustion chambers, ignition and flammability of hydrocarbon fuels, laminar flame propagation, turbulent flames, flame stabilization, diffusion flames, oscillations in combustors, and smoke and coke formation in the combustion of hydrocarbon-air mixtures. Theoretical background, basic experimental data, and practical significance to flight propulsion are presented.

  6. AIR EMISSIONS FROM COMBUSTION OF SOLVENT REFINED COAL

    EPA Science Inventory

    The report gives details of a Solvent Refined Coal (SRC) combustion test at Georgia Power Company's Plant Mitchell, March, May, and June 1977. Flue gas samples were collected for modified EPA Level 1 analysis; analytical results are reported. Air emissions from the combustion of ...

  7. 77 FR 60341 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... Source Performance Standards for Stationary Internal Combustion Engines'' (77 FR 33812). The June 7, 2012... Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion... Emission Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines...

  8. Combustion Safety for Appliances Using Indoor Air (Fact Sheet)

    SciTech Connect

    Not Available

    2014-05-01

    This measure guideline covers how to assess and carry out the combustion safety procedures for appliances and heating equipment that uses indoor air for combustion in low-rise residential buildings. Only appliances installed in the living space, or in an area freely communicating with the living space, vented alone or in tandem with another appliance are considered here. A separate measure guideline addresses combustion appliances located either within the living space in enclosed closets or side rooms or outside the living space in an adjacent area like an attic or garage that use outdoor air for combustion. This document is for inspectors, auditors, and technicians working in homes where energy upgrades are being conducted whether or not air infiltration control is included in the package of measures being applied. In the indoor combustion air case, guidelines summarized here are based on language provided in several of the codes to establish minimum requirements for the space using simplified prescriptive measures. In addition, building performance testing procedures are provided by testing agencies. The codes in combination with the test procedures offer comprehensive combustion safety coverage to address safety concerns, allowing inexperienced residential energy retrofit inspectors to effectively address combustion safety issues and allow energy retrofits to proceed.

  9. Dependence the amount of combustion air and its redistribution to primary and secondary combustion air and his depending on the boiler

    NASA Astrophysics Data System (ADS)

    Papučík, Štefan; Lenhard, Richard; Kaduchová, Katarína; Jandačka, Jozef; Koloničný, Jan; Horák, Jiří

    2014-08-01

    The production of solid pollutants is affected by several influences. The amount of combustion air and its redistribution to primary and secondary combustion air. The experimental device, what which has been examined the amount of the combustion air on the production of the solid pollutants, methods of measurement, measurements results and analysis of the results obtained will be described in the papers.

  10. Fuel-Air Mixing and Combustion in Scramjets

    NASA Technical Reports Server (NTRS)

    Drummond, J. P.; Diskin, Glenn S.; Cutler, A. D.

    2002-01-01

    Activities in the area of scramjet fuel-air mixing and combustion associated with the Research and Technology Organization Working Group on Technologies for Propelled Hypersonic Flight are described. Work discussed in this paper has centered on the design of two basic experiments for studying the mixing and combustion of fuel and air in a scramjet. Simulations were conducted to aid in the design of these experiments. The experimental models were then constructed, and data were collected in the laboratory. Comparison of the data from a coaxial jet mixing experiment and a supersonic combustor experiment with a combustor code were then made and described. This work was conducted by NATO to validate combustion codes currently employed in scramjet design and to aid in the development of improved turbulence and combustion models employed by the codes.

  11. What is Air? A Standard Model for Combustion Simulations

    SciTech Connect

    Cloutman, L D

    2001-08-01

    Most combustion devices utilize air as the oxidizer. Thus, reactive flow simulations of these devices require the specification of the composition of air as part of the physicochemical input. A mixture of only oxygen and nitrogen often is used, although in reality air is a more complex mixture of somewhat variable composition. We summarize some useful parameters describing a standard model of dry air. Then we consider modifications to include water vapor for creating the desired level of humidity. The ''minor'' constituents of air, especially argon and water vapor, can affect the composition by as much as about 5 percent in the mole fractions.

  12. Closed loop air cooling system for combustion turbines

    DOEpatents

    Huber, D.J.; Briesch, M.S.

    1998-07-21

    Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor and delivered to passages internal to one or more of a combustor and turbine hot parts. The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts. 1 fig.

  13. Closed loop air cooling system for combustion turbines

    DOEpatents

    Huber, David John; Briesch, Michael Scot

    1998-01-01

    Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor and delivered to passages internal to one or more of a combustor and turbine hot parts. The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts.

  14. EMISIONES AL AIRE DE LA COMBUSTION DE LLANTAS USADAS (SPANISH VERSION)

    EPA Science Inventory

    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

  15. Combustion performance evaluation of air staging of palm oil blends.

    PubMed

    Mohd Jaafar, Mohammad Nazri; Eldrainy, Yehia A; Mat Ali, Muhammad Faiser; Wan Omar, W Z; Mohd Hizam, Mohd Faizi Arif

    2012-02-21

    The problems of global warming and the unstable price of petroleum oils have led to a race to develop environmentally friendly biofuels, such as palm oil or ethanol derived from corn and sugar cane. Biofuels are a potential replacement for fossil fuel, since they are renewable and environmentally friendly. This paper evaluates the combustion performance and emission characteristics of Refined, Bleached, and Deodorized Palm Oil (RBDPO)/diesel blends B5, B10, B15, B20, and B25 by volume, using an industrial oil burner with and without secondary air. Wall temperature profiles along the combustion chamber axis were measured using a series of thermocouples fitted axially on the combustion chamber wall, and emissions released were measured using a gas analyzer. The results show that RBDPO blend B25 produced the maximum emission reduction of 56.9% of CO, 74.7% of NOx, 68.5% of SO(2), and 77.5% of UHC compared to petroleum diesel, while air staging (secondary air) in most cases reduces the emissions further. However, increasing concentrations of RBDPO in the blends also reduced the energy released from the combustion. The maximum wall temperature reduction was 62.7% for B25 at the exit of the combustion chamber. PMID:22296110

  16. Indoor air quality environmental information handbook: Combustion sources

    SciTech Connect

    Not Available

    1990-06-01

    This environmental information handbook was prepared to assist both the non-technical reader (i.e., homeowner) and technical persons (such as researchers, policy analysts, and builders/designers) in understanding the current state of knowledge regarding combustion sources of indoor air pollution. Quantitative and descriptive data addressing the emissions, indoor concentrations, factors influencing indoor concentrations, and health effects of combustion-generated pollutants are provided. In addition, a review of the models, controls, and standards applicable to indoor air pollution from combustion sources is presented. The emphasis is on the residential environment. The data presented here have been compiled from government and privately-funded research results, conference proceedings, technical journals, and recent publications. It is intended to provide the technical reader with a comprehensive overview and reference source on the major indoor air quality aspects relating to indoor combustion activities, including tobacco smoking. In addition, techniques for determining potential concentrations of pollutants in residential settings are presented. This is an update of a 1985 study documenting the state of knowledge of combustion-generated pollutants in the indoor environment. 191 refs., 51 figs., 71 tabs.

  17. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HOUSING AND URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Heating, Cooling and...: (1) An integral vent system listed or certified as part of the appliance. (2) A venting system... appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air...

  18. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Venting, ventilation and combustion air. 3280.710 Section 3280.710 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN...

  19. 75 FR 80761 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ... Reciprocating Internal Combustion Engines AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of... air pollutants for reciprocating internal combustion engines and requesting public comment on one.... List of Subjects in 40 CFR Part 63 Administrative practice and procedure, Air pollution...

  20. Air supply system for an internal combustion engine

    SciTech Connect

    Eftink, A.J.

    1991-03-12

    This patent describes a reciprocating piston internal combustion engine having a crankshaft and at least two cylinders, each cylinder having a displacement volume V{sub 1}, the improved means for supplying air to each cylinder. It comprises: a rotary, trochoidal chamber air pump defining at least one pair of pumping chambers, the number of pumping chambers being equal to the number of cylinders in the engine; air intake conduits connecting each pumping chamber to one cylinder of the engine; a rotor rotatable in each pair of pumping chambers, the rotor having three faces such that passage of a face of the rotor through a pumping chamber forces air in the pumping chamber into the associated air intake conduit and, consequently, into the engine cylinder; and means interconnecting the rotor and the crankshaft so as to rotate the rotor approximately one revolution for every three revolutions of the crankshaft.

  1. Confined combustion of TNT explosion products in air

    SciTech Connect

    Chandler, J; Ferguson, R E; Forbes, J; Kuhl, A L; Oppenheim, A K; Spektor, R

    1998-08-31

    Effects of turbulent combustion induced by explosion of a 0.8 kg cylindrical charge of TNT in a 17 m3 chamber filled with air, are investigated. The detonation wave in the charge transforms the solid explosive (C7H5N3O6) to gaseous products, rich (~20% each) in carbon dust and carbon monoxide. The detonation pressure (~210 kb) thereby engendered causes the products to expand rapidly, driving a blast wave into the surrounding air. The interface between the products and air, being essentially unstable as a consequence of strong acceleration to which it is subjected within the blast wave, evolves into a turbulent mixing layer-a process enhanced by shock reflections from the walls. Under such circumstances rapid combustion takes place where the expanded detonation products play the role of fuel. Its dynamic effect is manifested by the experimental measurement of ~3 bar pressure increase in the chamber, in contrast to ~1bar attained by a corresponding TNT explosion in nitrogen. The experiments were modeled as a turbulent combustion in an unmixed system at infinite Reynolds, Peclet and DamkGhler numbers. The CFD solution was obtained by a high-order Godunov scheme using an AMR (Adaptive Mesh Refinement) to trace the turbulent mixing on the computational grid in as much detail as possible. The evolution of the mass fraction of fuel consumed by combustion thus determined exhibited the properties of an exponential decay following a sharp initiation. The results reveal all the dynamic features of the exothermic process of combustion controlled by fluid mechanic transport in a highly turbulent field, in contrast to those elucidated by the conventional reaction-diffusion model.

  2. Flammability and sensitivity of materials in oxygen-enriched atmospheres

    SciTech Connect

    Stoltzfus, J.M.; Benz, F.J.; Stradling, J.S. )

    1989-01-01

    This book presents five papers on development and evaluation of test methods. It addresses the ignition and combustion of nonmetallic and metallic materials. Analysis and testing of oxygen systems are included.

  3. Particulate emissions from combustion of biomass in conventional combustion (air) and oxy-combustion conditions

    NASA Astrophysics Data System (ADS)

    Ruscio, Amanda Deanne

    Oxy-fuel combustion is a viable technology for new and existing coal-fired power plants, as it facilitates carbon capture and thereby, can reduce carbon dioxide emissions. The use of biomass as an energy source is another popular strategy to reduce carbon dioxide emissions as they are considered nearly carbon dioxide neutral. If the use of biomass is combined with oxy-fuel combustion, negative net emissions of carbon dioxide are possible. This work examined the particulate emissions from combustion of pulverized biomass residues burning in either conventional or oxy-fuel environments. Combustion of three biomasses (olive residue, corn residue, and torrefied pine sawdust) occurred in a laboratory-scale laminar-flow drop tube furnace (DTF) heated to 1400 K. The O2 mole fraction was increased from 20% to 60% in N2 environments while a range of 30% to 60% O2 mole fractions were used in CO2 environments to represent plausible dry oxy-fuel combustion conditions. Submicron particulate matter (PM1) emission yields of all three fuels were typically lower in O2/CO2 environments than in O2/N2 environments. When the oxygen mole fraction was increased, the PM1 yields typically increased. The mass fractions of submicron particulate matter (PM1/PM18) collected from biomass combustion were higher than those of coal combustion. PM 1 constituted approximately 50 wt% of the collected ash particles in PM18 in each environment, whereas the corresponding submicron emissions from coal constituted approximately 20 wt%. Changing the background gas had little effect on the chemical composition of the PM1 particles. Unlike the submicron particles collected from coal which contained high amounts of silicon and aluminum, high amounts of alkalis (potassium, calcium, and sodium) and chlorine were the major elements observed in PM1 from the biomasses. In addition, phosphorous and sulfur also existed in high amounts in PM1 of corn residue. Super-micron particles (PM1-18) yields exhibited no clear

  4. Combustion gas properties. 2: Natural gas fuel and dry air

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Jones, R. E.; Trout, A. M.; Mcbride, B. J.

    1985-01-01

    A series of computations has been made to produce the equilibrium temperature and gas composition for natural gas fuel and dry air. The computed tables and figures provide combustion gas property data for pressures from 0.5 to 50 atmospheres and equivalence ratios from 0 to 2.0. Only samples tables and figures are provided in this report. The complete set of tables and figures is provided on four microfiche films supplied with this report.

  5. Large-Eddy Simulations of Fuel-Air Mixing and Combustion in an Internal Combustion Engine

    NASA Astrophysics Data System (ADS)

    Sone, Kazuo; Menon, Suresh

    2000-11-01

    Past studies of internal combustion (IC) engine steady-state flow field have employed the well-known KIVA code for steady-state predictions. However, it is also well known that this code is incapable of accurately capturing the impact of unsteady fuel-air mixing on the combustion process. Here, the latest KIVA-3V code has been modified to carry out large-eddy simulations (LES). In particular, the RANS k-e model has been replaced by a subgrid kinetic energy model and a fourth-order ENO scheme has been implemented to increase the accuracy of the discretization of the advection term. Finally, a subgrid model to simulate the small-scale turbulent mixing, combustion and heat release is implemented for reacting flows. Simulations using the new version of KIVA3V denoted here as KIVALES of temporal mixing layers and flows past rearward facing step demonstrate the improved accuracy of the LES model. Accuracy of the prediction is demonstrated by comparing with DNS, LES and experimental results obtained in the past. Finally, the new code is employed to simulate fuel-air mixing and combustion in a typical IC engine. Comparison with predictions using the conventional KIVA is used to demonstrate the ability of the new code.

  6. Air intake side secondary air supply system for an internal combustion engine

    SciTech Connect

    Kobayashi, H.; Tomobe, N.

    1987-03-10

    This patent describes an air intake side secondary air supply system for an internal combustion engine having a choke valve and a throttle valve in an intake air passage. The system is adapted to supply an air intake side secondary air into an intake air passage downstream of the throttle valve by a control valve and in response to an operating condition of the engine during a cold operation of the engine. The improvement described here comprises means for detecting a no-load operating state of the engine during the cold operation of the engine in which the choke valve is actuated to close the intake air passage, and means for stopping a supply of the air intake side secondary air upon detection of the non-load operating state so as to enrich an air-fuel mixture supplied to the engine.

  7. Experimental and theoretical analysis results for high temperature air combustion

    SciTech Connect

    Tanigawa, Tadashi; Morita, Mitsunobu

    1998-07-01

    With Japan's preparation of its Action program to prevent global warming in 1990 and the holding of the United National Conference on Environment and Development (the Earth Summit) in 1992 as a backdrop, reflecting the global effort to protect the environment, a high performance industrial furnace development project was launched in 1993 by the New Energy and Industrial Technology Development Organization (NEDO). This project focuses on the development of a combustion technology which uses air that is preheated to extremely high temperatures (above 1,000 C), heretofore considered impossible. Not only can this technology reduce carbon dioxide emission, thought to cause the greenhouse effect, by over 30%, but it can also reduce nitrogen oxide emission by nearly half. This new technology makes use of the recently-developed high-cycle regenerative heat exchanger, for preheating the furnace air supply. This exchanger preheats air to above 1,000 C, much higher than for conventional furnaces, and then this air is injected with fuel. R and D data have shown that CO{sub 2} and NO{sub x} emissions can be reduced markedly. However, the theoretical analysis is yet to be made, thereby hampering efforts to have this advanced technology become widely adopted. This project accumulated new data related to uniform temperature distribution, high energy heat transfer and low NO{sub x} as common characteristics of high temperature air combustion.

  8. Fuel-Air Mixing and Combustion in Scramjets. Chapter 6

    NASA Technical Reports Server (NTRS)

    Drummond, J. Philip; Diskin, Glenn S.; Cutler, Andrew D.

    2006-01-01

    At flight speeds, the residence time for atmospheric air ingested into a scramjet inlet and exiting from the engine nozzle is on the order of a millisecond. Therefore, fuel injected into the air must efficiently mix within tens of microseconds and react to release its energy in the combustor. The overall combustion process should be mixing controlled to provide a stable operating environment; in reality, however, combustion in the upstream portion of the combustor, particularly at higher Mach numbers, is kinetically controlled where ignition delay times are on the same order as the fluid scale. Both mixing and combustion time scales must be considered in a detailed study of mixing and reaction in a scramjet to understand the flow processes and to ultimately achieve a successful design. Although the geometric configuration of a scramjet is relatively simple compared to a turbomachinery design, the flow physics associated with the simultaneous injection of fuel from multiple injector configurations, and the mixing and combustion of that fuel downstream of the injectors is still quite complex. For this reason, many researchers have considered the more tractable problem of a spatially developing, primarily supersonic, chemically reacting mixing layer or jet that relaxes only the complexities introduced by engine geometry. All of the difficulties introduced by the fluid mechanics, combustion chemistry, and interactions between these phenomena can be retained in the reacting mixing layer, making it an ideal problem for the detailed study of supersonic reacting flow in a scramjet. With a good understanding of the physics of the scramjet internal flowfield, the designer can then return to the actual scramjet geometry with this knowledge and apply engineering design tools that more properly account for the complex physics. This approach will guide the discussion in the remainder of this section.

  9. Simultaneous identification of multi-combustion-intermediates of alkanol-air flames by femtosecond filament excitation for combustion sensing

    PubMed Central

    Li, Helong; Chu, Wei; Xu, Huailiang; Cheng, Ya; Chin, See-Leang; Yamanouchi, Kaoru; Sun, Hong-Bo

    2016-01-01

    Laser filamentation produced by the propagation of intense laser pulses in flames is opening up new possibility in application to combustion diagnostics that can provide useful information on understanding combustion processes, enhancing combustion efficiency and reducing pollutant products. Here we present simultaneous identification of multiple combustion intermediates by femtosecond filament excitation for five alkanol-air flames fueled by methanol, ethanol, n-propanol, n-butanol, and n-pentanol. We experimentally demonstrate that the intensities of filament-induced photoemission signals from the combustion intermediates C, C2, CH, CN increase with the increasing number of carbons in the fuel molecules, and the signal ratios between the intermediates (CH/C, CH/C2, CN/C, CH/C2, CN/CH) are different for different alkanol combustion flames. Our observation provides a way for sensing multiple combustion components by femtosecond filament excitation in various combustion conditions that strongly depend on the fuel species. PMID:27250021

  10. Simultaneous identification of multi-combustion-intermediates of alkanol-air flames by femtosecond filament excitation for combustion sensing.

    PubMed

    Li, Helong; Chu, Wei; Xu, Huailiang; Cheng, Ya; Chin, See-Leang; Yamanouchi, Kaoru; Sun, Hong-Bo

    2016-01-01

    Laser filamentation produced by the propagation of intense laser pulses in flames is opening up new possibility in application to combustion diagnostics that can provide useful information on understanding combustion processes, enhancing combustion efficiency and reducing pollutant products. Here we present simultaneous identification of multiple combustion intermediates by femtosecond filament excitation for five alkanol-air flames fueled by methanol, ethanol, n-propanol, n-butanol, and n-pentanol. We experimentally demonstrate that the intensities of filament-induced photoemission signals from the combustion intermediates C, C2, CH, CN increase with the increasing number of carbons in the fuel molecules, and the signal ratios between the intermediates (CH/C, CH/C2, CN/C, CH/C2, CN/CH) are different for different alkanol combustion flames. Our observation provides a way for sensing multiple combustion components by femtosecond filament excitation in various combustion conditions that strongly depend on the fuel species. PMID:27250021

  11. Simultaneous identification of multi-combustion-intermediates of alkanol-air flames by femtosecond filament excitation for combustion sensing

    NASA Astrophysics Data System (ADS)

    Li, Helong; Chu, Wei; Xu, Huailiang; Cheng, Ya; Chin, See-Leang; Yamanouchi, Kaoru; Sun, Hong-Bo

    2016-06-01

    Laser filamentation produced by the propagation of intense laser pulses in flames is opening up new possibility in application to combustion diagnostics that can provide useful information on understanding combustion processes, enhancing combustion efficiency and reducing pollutant products. Here we present simultaneous identification of multiple combustion intermediates by femtosecond filament excitation for five alkanol-air flames fueled by methanol, ethanol, n-propanol, n-butanol, and n-pentanol. We experimentally demonstrate that the intensities of filament-induced photoemission signals from the combustion intermediates C, C2, CH, CN increase with the increasing number of carbons in the fuel molecules, and the signal ratios between the intermediates (CH/C, CH/C2, CN/C, CH/C2, CN/CH) are different for different alkanol combustion flames. Our observation provides a way for sensing multiple combustion components by femtosecond filament excitation in various combustion conditions that strongly depend on the fuel species.

  12. Air flow management in an internal combustion engine through the use of electronically controlled air jets

    SciTech Connect

    Swain, M.R.

    1988-12-27

    This patent describes a means for producing an air/fuel mixture in the valve pocket and means for directing the air/fuel mixture past the intake valve into the combustion chamber, the improvement comprising a device for generating a swirling flow of the air/fuel mixture in the combustion chamber to thereby obtain greater combustion stability. The device has a nozzle positioned within the valve pocket and directed at an acute angle toward the intake valve comprising at least one opening for receiving air, connected to a first pathway, and at least one opening for expelling air, connected, to a second pathway joined to the first pathway and extending to the expulsion opening. The device also includes a means for controlling the flow of air through the pathway and out the expulsion opening comprising: (i) a stopper having sides complementary in shape to the pair of opposed arcuate walls movable from an open position allowing air through the pathway to a closed position, wherein the sides of the stopper are in a sealed relationship with the opposed arcaute sides of the junction thereby preventing the flow of air through the second pathway and out of the expulsion opening; and (ii) an electronic computer which determines the size and duration of the pathway opening.

  13. Inhibiting the combustion of air-acetylene mixtures

    NASA Astrophysics Data System (ADS)

    Kopylov, S. N.; Gubina, T. V.

    2016-01-01

    The effect propane, methane, and a mixture of 18 vol % C3H6-40 vol % C3H8-42 vol % C4H10 have on the combustion of air-acetylene mixtures is investigated experimentally. The upper concentration limit of flame propagation, maximum explosion pressure, and maximum rate of rise of explosion pressure are determined. It is found that propane and a mixture of 18 vol % C3H6-40 vol % C3H8-42 vol % C4H10 are strong inhibitors of combustion of acetylene in its concentration ranges of 2-8 vol %. The inhibition effect becomes weaker as the acetylene content in the mixture increases. It disappears completely at C2H2 concentrations exceeding 15 vol %. The above experimental findings are explained using the proposed scheme of acetylene oxidation.

  14. Species measurements in a hypersonic, hydrogen-air, combustion wake

    NASA Technical Reports Server (NTRS)

    Skinner, K. A.; Stalker, R. J.

    1995-01-01

    A continuously sampling, time-of-flight mass spectrometer has been used to measure relative species concentrations in a two-dimensional, hydrogen-air combustion wake at mainstream Mach numbers exceeding 5. The experiments, which were conducted in a free piston shock tunnel, yielded distributions of hydrogen, oxygen, nitrogen, water and nitric oxide at stagnation enthalpies ranging from 5.6 MJ kg(exp -1) to 1.2 MJ kg(exp -1) and at a distance of approximately 100 times the thickness of the initial hydrogen jet. The amount of hydrogen that was mixed in stoichiometric proportions was approximately independent of the stagnation enthalpy, in spite of the fact that the proportion of hydrogen in the wake increased with stagnation enthalpy. Roughly 50 percent of the mixed hydrogen underwent combustion at the highest enthalpy. The proportion of hydrogen reacting to water could be approximately predicted using reaction rates based on mainstream temperatures.

  15. Species measurements in a hypersonic, hydrogen-air, combustion wake

    SciTech Connect

    Skinner, K.A.; Stalker, R.J.

    1996-09-01

    A continuously sampling, time-of-flight mass spectrometer has been used to measure relative species concentrations in a two-dimensional, hydrogen-air combustion wake at mainstream Mach numbers exceeding 5. The experiments, in a free piston shock tunnel, yielded distributions of hydrogen, oxygen, nitrogen, water, and nitric oxide at stagnation enthalpies ranging from 5.6 MJ/kg to 12.2 MJ/kg and at a distance of approximately 100s times the thickness of the initial hydrogen jet. The amount of hydrogen mixed in stoichiometric proportions was approximately independent of the stagnation enthalpy, despite the fact that the proportion of hydrogen in the wake was increased with stagnation enthalpy. Roughly 50% of the mixed hydrogen underwent combustion at the highest enthalpy. The proportion of hydrogen reacting to water could be approximately predicted using reaction rates based on mainstream temperatures.

  16. Optimization of Microwave Roasting for Dechlorination of CuCl Residue under Oxygen-Enriched Condition

    NASA Astrophysics Data System (ADS)

    Zhanyong, Guo; Shaohua, Ju; Jinhui, Peng; Libo, Zhang; Ting, Lei

    2016-02-01

    The clean utilization of the residue containing chloride, such as zinc oxide dust and CuCl residue, produced from zinc hydrometallurgy is very important for the recycle of valuable metals. In this paper, a new technology for dechlorination of the CuCl residue through thermal treatment with application of microwave and oxygen-enriched air roasting is brought out. And the response surface methodology (RSM) based on five-level, three-variable and central composite design (CCD) was used to optimize the operation parameters for increasing the dechlorination efficiency. The effects of temperature, roasting time and oxygen consumption on the dechlorination efficiency were studied and the optimal process conditions were identified. In addition, X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectroscopy were used to characterize the dechlorination process under the optimum condition. The results showed that the experimental data were fitted to a second-order polynomial equation. The optimized process conditions are identified to be a roasting temperature of 451°, heating duration of 114 min and oxygen consumption of 2.4 times the theoretical oxygen demand. A dechlorination efficiency of 96.4% could be achieved at the optimal process conditions.

  17. RESEARCH AREA -- MUNICIPAL WASTE COMBUSTION (AIR POLLUTION TECHNOLOGY BRANCH, AIR POLLUTION PREVENTION AND CONTROL DIVISION, NRMRL)

    EPA Science Inventory

    The municipal waste combustion (MWC) program supports the development of revised rules for air pollutant emissions from the MWC source category. Basic research is performed on MWC pollutant formation and control mechanisms for acid gas, trace organic, and trace metal emissions. T...

  18. Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

    PubMed

    Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

    2016-05-01

    Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. PMID:26894568

  19. Combustion and gasification characteristics of pulverized coal using high-temperature air

    SciTech Connect

    Hanaoka, R.; Nakamura, M.; Kiga, T.; Kosaka, H.; Iwahashi, T.; Yoshikawa, K.; Sakai, M.; Muramatsu, K.; Mochida, S.

    1998-07-01

    In order to confirm performance of high-temperature-air combusting of pulverized coal, laboratory-scale combustion and gasification tests of coal were conducted changing air temperature and oxygen concentration in the air. Theses were conducted in a drop tube furnace of 200mm in inside diameter and 2,000mm in length. The furnace was heated by ceramic heater up to 1,300 C. A high-temperature air preheater utilizing the HRS (High Cycle Regenerative Combustion System) was used to obtain high-temperature combustion air. As the results, NOx emission was reduced when pulverized coal was fired with high-temperature-air. On the other hand, by lower oxygen concentration in combustion air diluted by nitrogen, NOx emission slightly decreased while became higher under staging condition.

  20. Future Directions of Supersonic Combustion Research: Air Force/NASA Workshop on Supersonic Combustion

    NASA Technical Reports Server (NTRS)

    Tishkoff, Julian M.; Drummond, J. Philip; Edwards, Tim; Nejad, Abdollah S.

    1997-01-01

    The Air Force Office of Scientific Research, the Air Force Wright Laboratory Aero Propulsion and Power Directorate, and the NASA Langley Research Center held a joint supersonic combustion workshop on 14-16 May 1996. The intent of this meeting was to: (1) examine the current state-of-the-art in hydrocarbon and/or hydrogen fueled scramjet research; (2) define the future direction and needs of basic research in support of scramjet technology; and (3) when appropriate, help transition basic research findings to solve the needs of developmental engineering programs in the area of supersonic combustion and fuels. A series of topical sessions were planned. Opening presentations were designed to focus and encourage group discussion and scientific exchange. The last half-day of the workshop was set aside for group discussion of the issues that were raised during the meeting for defining future research opportunities and directions. The following text attempts to summarize the discussions that took place at the workshop.

  1. New Compressor Added to Glenn's 450- psig Combustion Air System

    NASA Technical Reports Server (NTRS)

    Swan, Jeffrey A.

    2000-01-01

    In September 1999, the Central Process Systems Engineering Branch and the Maintenance and the Central Process Systems Operations Branch, released for service a new high pressure compressor to supplement the 450-psig Combustion Air System at the NASA Glenn Research Center at Lewis Field. The new compressor, designated C-18, is located in Glenn s Central Air Equipment Building and is remotely operated from the Central Control Building. C-18 can provide 40 pounds per second (pps) of airflow at pressure to our research customers. This capability augments our existing system capacity (compressors C 4 at 38 pps and C-5 at 32 pps), which is generated from Glenn's Engine Research Building. The C-18 compressor was originally part of Glenn's 21-Inch Hypersonic Tunnel, which was transferred from the Jet Propulsion Laboratory to Glenn in the mid-1980's. With the investment of construction of facilities funding, the compressor was modified, new mechanical and electrical support equipment were purchased, and the unit was installed in the basement of the Central Air Equipment Building. After several weeks of checkout and troubleshooting, the new compressor was ready for long-term, reliable operations. With a total of 110 pps in airflow now available, Glenn is well positioned to support the high-pressure air test requirements of our research customers.

  2. Considerations of Air Flow in Combustion Chambers of High-Speed Compression-Ignition Engines

    NASA Technical Reports Server (NTRS)

    Spanogle, J A; Moore, C S

    1932-01-01

    The air flow in combustion chambers is divided into three fundamental classes - induced, forced, and residual. A generalized resume is given of the present status of air flow investigations and of the work done at this and other laboratories to determine the direction and velocity of air movement in auxiliary and integral combustion chambers. The effects of air flow on engine performance are mentioned to show that although air flow improves the combustion efficiency, considerable induction, friction, and thermal losses must be guarded against.

  3. Effect of air-staging on anthracite combustion and NOx formation

    SciTech Connect

    Weidong Fan; Zhengchun Lin; Youyi Li; Jinguo Kuang; Mingchuan Zhang

    2009-01-15

    Experiments were carried out in a multipath air inlet one-dimensional furnace to assess NOx emission characteristics of the staged combustion of anthracite coal. These experiments allowed us to study the impact of pulverized coal fineness and burnout air position on emission under both deep and shallow air-staged combustion conditions. We also studied the impact of char-nitrogen release on both the burning-out process of the pulverized coal and the corresponding carbon content in fly ash. We found that air-staged combustion affects a pronounced reduction in NOx emissions from the combustion of anthracite coal. The more the air is staged, the more NOx emission is reduced. In shallow air-staged combustion (f{sub M} = 0.85), the fineness of the pulverized coal strongly influences emissions, and finer coals result in lower emissions. Meanwhile, the burnout air position has only a weak effect. In the deep air-staged combustion (f{sub M} = 0.6), the effect of coal fineness is smaller, and the burnout air position has a stronger effect. When the primary combustion air is stable, NOx emissions increase with increasing burnout air. This proves that, in the burnout zone, coal char is responsible for the discharge of fuel-nitrogen that is oxidized to NOx. The measurement of secondary air staging in a burnout zone can help inhibit the oxidization of NO caused by nitrogen release. Air-staged combustion has little effect on the burnout of anthracite coal, which proves to be suitable for air-staged combustion. 31 refs., 11 figs., 1 tab.

  4. Atmospheric pressure fluctuations and oxygen enrichment in waste tanks

    SciTech Connect

    Kurzeja, R.J.; Weber, A.H.

    1993-07-01

    During In-Tank Precipitation (ITP) processing radiolytic decomposition of tetraphenylborate and water can produce benzene and hydrogen, which, given sufficiently high oxygen concentrations, can deflagrate. To prevent accumulations of benzene and hydrogen and avoid deflagration, continuous nitrogen purging is maintained. If the nitrogen purging is interrupted by, for example, a power failure, outside air will begin to seep into the tank through vent holes and cracks. Eventually a flammable mixture of benzene, hydrogen, and oxygen will occur (deflagration). However, this process is slow under steady-state conditions (constant pressure) and mechanisms to increase the exchange rate with the outside atmosphere must be considered. The most important mechanism of this kind is from atmospheric pressure fluctuations in which an increase in atmospheric pressure forces air into the tank which then mixes with the hydrogen-benzene mixture. The subsequent decrease in atmospheric pressure causes venting from the tank of the mixture -- the net effect being an increase in the tank`s oxygen concentration. Thus, enrichment occurs when the atmospheric pressure increases but not when the pressure decreases. Moreover, this natural atmospheric {open_quotes}pumping{close_quotes} is only important if the pressure fluctuations take place on a time scale longer than the characteristic mixing time scale (CMT) of the tank. If pressure fluctuations have a significantly higher frequency than the CMT, outside air will be forced into the tank and then out again before any significant mixing can occur. The CMT is not known for certain, but is estimated to be between 8 and 24 hours. The purpose of this report is to analyze yearly pressure fluctuations for a five year period to determine their statistical properties over 8 and 24-hour periods. The analysis also includes a special breakdown into summer and winter seasons and an analysis of 15-minute data from the SRTC Climatology Site.

  5. Investigation of Ignition and Combustion Processes of Diesel Engines Operating with Turbulence and Air-storage Chambers

    NASA Technical Reports Server (NTRS)

    Petersen, Hans

    1938-01-01

    The flame photographs obtained with combustion-chamber models of engines operating respectively, with turbulence chamber and air-storage chambers or cells, provide an insight into the air and fuel movements that take place before and during combustion in the combustion chamber. The relation between air velocity, start of injection, and time of combustion was determined for the combustion process employing a turbulence chamber.

  6. The effect of intraoral suction on oxygen-enriched surgical environments: a mechanism for reducing the risk of surgical fires.

    PubMed

    VanCleave, Andrea M; Jones, James E; McGlothlin, James D; Saxen, Mark A; Sanders, Brian J; Vinson, LaQuia A

    2014-01-01

    In this study, a mechanical model was applied in order to replicate potential surgical fire conditions in an oxygen-enriched environment with and without high-volume suction typical for dental surgical applications. During 41 trials, 3 combustion events were measured: an audible pop, a visible flash of light, and full ignition. In at least 11 of 21 trials without suction, all 3 conditions were observed, sometimes with an extent of fire that required early termination of the experimental trial. By contrast, in 18 of 20 with-suction trials, ignition did not occur at all, and in the 2 cases where ignition did occur, the fire was qualitatively a much smaller, candle-like flame. Statistically comparing these 3 combustion events in the no-suction versus with-suction trials, ignition (P = .0005), audible pop (P = .0211), and flash (P = .0092) were all significantly more likely in the no-suction condition. These results suggest a possible significant and new element to be added to existing surgical fire safety protocols toward making surgical fires the "never-events" they should be. PMID:25517551

  7. Late - Cycle Injection of Air/Oxygen - Enriched Air for Diesel Exhaust Emissions Control

    SciTech Connect

    Mather, Daniel

    2000-08-20

    Reduce the ''Engine Out'' particulates using the ''In Cylinder'' technique of late cycle auxiliary gas injection (AGI). Reduce the ''Engine Out'' NOx by combining AGI with optimization of fuel injection parameters. Maintain or Improve the Fuel Efficiency.

  8. Adaptation of Combustion Principles to Aircraft Propulsion. Volume I; Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C (Editor); Hibbard, Robert R (Editor)

    1955-01-01

    The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.

  9. Thermodynamic, transport, and flow properties of gaseous products resulting from combustion of methane-air-oxygen

    NASA Technical Reports Server (NTRS)

    Klich, G. F.

    1976-01-01

    Results of calculations to determine thermodynamic, transport, and flow properties of combustion product gases are presented. The product gases are those resulting from combustion of methane-air-oxygen and methane-oxygen mixtures. The oxygen content of products resulting from the combustion of methane-air-oxygen mixtures was similiar to that of air; however, the oxygen contained in products of methane-oxygen combustion ranged from 20 percent by volume to zero for stoichiometric combustion. Calculations were made for products of reactant mixtures with fuel percentages, by mass, of 7.5 to 20. Results are presented for specific mixtures for a range of pressures varying from 0.0001 to 1,000 atm and for temperatures ranging from 200 to 3,800 K.

  10. An experimental study on high temperature and low oxygen air combustion

    NASA Astrophysics Data System (ADS)

    Kim, W. B.; Chung, D. H.; Yang, J. B.; Noh, D. S.

    2000-06-01

    High temperature preheated and diluted air combustion has been confirmed as the technology, mainly applied to industrial furnaces and kilns, to realize higher thermal efficiency and lower emissions. The purpose of this study was to investigate fundamental aspects of the above-mentioned combustion experimentally and to compare with those in ordinary hydrocarbon combustion with room temperature air. The test items were exhaust gas components of CO, NOx, flame shape and radical components of CH, OH and C2, which were measured with gas analyser, camera and ICCD(Intensified Charged - Coupled Device) camera. Many phenomena as results appeared in combustion with the oxidizer, low oxygen concentration and extremely high temperature air, such as expansion of the flammable limits, increased flame propagation speed, it looked so strange as compared with those in existing combustion technology. We confirmed that such extraordinary phenomena were believable through the hot-test experiment.

  11. Mechanism of influence water vapor on combustion characteristics of propane-air mixture

    NASA Astrophysics Data System (ADS)

    Larionov, V. M.; Mitrofanov, G. A.; Sachovskii, A. V.; Kozar, N. K.

    2016-01-01

    The article discusses the results of an experimental study of the effect of water vapor at the flame temperature. Propane-butane mixture with air is burning on a modified Bunsen burner. Steam temperature was varied from 180 to 260 degrees. Combustion parameters changed by steam temperature and its proportion in the mixture with the fuel. The fuel-air mixture is burned in the excess air ratio of 0.1. It has been established that the injection of steam changes the characteristics of combustion fuel-air mixture and increase the combustion temperature. The concentration of CO in the combustion products is substantially reduced. Raising the temperature in the combustion zone is associated with increased enthalpy of the fuel by the added steam enthalpy. Reducing the concentration of CO is caused by decrease in the average temperature in the combustion zone by applying steam. Concentration of active hydrogen radicals and oxygen increases in the combustion zone. That has a positive effect on the process of combustion.

  12. 77 FR 37361 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-21

    ....gov/fdsys/pkg/FR-2012-06-07/pdf/2012-13193.pdf and also in the docket identified below. The public... Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion... proposed rule, ``National Emission Standards for Hazardous Air Pollutants for Reciprocating...

  13. Environmentally sound thermal energy extraction from coal and wastes using high temperature air combustion technology

    SciTech Connect

    Yoshikawa, Kunio

    1999-07-01

    High temperature air combustion is one of promising ways of burning relatively low BTU gas obtained from gasification of low grade coal or wastes. In this report, the author proposes a new power generation system coupled with high temperature air gasification of coal/wastes and high temperature air combustion of the syngas from coal/wastes. This system is realized by employing Multi-staged Enthalpy Extraction Technology (MEET). The basic idea of the MEET system is that coal or wastes are gasified with high temperature air of about 1,000 C, then the generated syngas is cooled in a heat recovery boiler to be cleaned-up in a gas cleanup system (desulfurization, desalinization and dust removal). Part of thermal energy contained in this cleaned-up syngas is used for high temperature air preheating, and the complete combustion of the fuel gas is done using also high temperature air for driving gas turbines or steam generation in a boiler.

  14. Afterburner for combustion of starved-air combustor fuel gas containing suspended solid fuel and fly ash

    SciTech Connect

    Fitch, R.E.; Tucker, G.H.

    1982-06-01

    An afterburner for use as a secondary combustion chamber in a starved-air combustor system to further combust any combustible material in the combustion gas and entrained solid particle material discharge from the combustion chamber of the starved-air combustor system. The afterburner is lined with refractory and includes a diverter plate positioned transversely to the incoming flow of combustion gases. The afterburner is divided into a plurality of reaction zones, each of which has an associated reaction air supply. The diverter plate imparts a cyclonic flow to the combustion gas which is enhanced by air injected in the combustion zones. The temperature of the gas discharged from the afterburner is monitored and the flow of reaction air controlled responsive to changes in discharge gas temperature from a predetermined temperature.

  15. Experimental investigation of wood combustion in a fixed bed with hot air

    SciTech Connect

    Markovic, Miladin Bramer, Eddy A.; Brem, Gerrit

    2014-01-15

    Highlights: • Upward combustion is a new combustion concept with ignition by hot primary air. • Upward combustion has three stages: short drying, rapid devolatilization and char combustion. • Variation of fuel moisture and inert content have little influence on the combustion. • Experimental comparison between conventional and upward combustion is presented. - Abstract: Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignition occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T > 220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1 m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of

  16. Two-dimensional distribution of flame fluctuation during highly preheated air combustion

    SciTech Connect

    Kitagawa, Kuniyuki; Konishi, Noriyuki; Arai, Norio; Gupta, A.K.

    1998-07-01

    The effect of highly preheated combustion air on the spatial distributions of flame fluctuations and temperature is presented here. Several propane flames, produced with the cross-flow diffusion of gas into highly preheated combustion air having controlled oxygen content, have been examined here by an array of thermocouples and a spectrovideo camera consisting of a monochromator and a high speed UV video camera. Spontaneous emission signal of flames produced from the regenerative combustion system was passed through the monochromator to construct a spectroscopically resolved image. The time resolved images were observed by the high speed UV video camera. Fast Fourier transform (FFT) was then applied to each image, at each pixel location of the detector in the video camera. This provided frequency-domain spectra, which then also allowed one to reconstruct the two-dimensional distribution of flame fluctuation. The results show that lame fluctuations in the high temperature combustion region are significantly lower with highly preheated combustion air. The two-dimensional profiles of the flame vibrational temperature, based on modified two-line method of two C{sub 2} bands, indicate that dilution of the preheated air drastically reduces the temperature gradient. The two-dimensional profiles of temperature as well as their fluctuations were measured by a thermocouple array at 24 points in the combustion chamber. The results indicated tendencies similar to those obtained spectroscopically, i.e., a drastic decrease in the flame fluctuations with highly preheated combustion air. The thermal field uniformity with high temperature combustion air was found to be improved even at low oxygen concentrations in the air.

  17. Measure Guideline: Combustion Safety for Natural Draft Appliances Using Indoor Air

    SciTech Connect

    Brand, L.

    2014-04-01

    This measure guideline covers how to assess and carry out the combustion safety procedures for appliances and heating equipment that uses indoor air for combustion in low-rise residential buildings. Only appliances installed in the living space, or in an area freely communicating with the living space, vented alone or in tandem with another appliance are considered here. A separate measure guideline addresses combustion appliances located either within the living space in enclosed closets or side rooms or outside the living space in an adjacent area like an attic or garage that use outdoor air for combustion. This document is for inspectors, auditors, and technicians working in homes where energy upgrades are being conducted whether or not air infiltration control is included in the package of measures being applied. In the indoor combustion air case, guidelines summarized here are based on language provided in several of the codes to establish minimum requirements for the space using simplified prescriptive measures. In addition, building performance testing procedures are provided by testing agencies. The codes in combination with the test procedures offer comprehensive combustion safety coverage to address safety concerns, allowing inexperienced residential energy retrofit inspectors to effectively address combustion safety issues and allow energy retrofits to proceed.

  18. Use of fluidic oscillator to measure fuel-air ratios of combustion gases

    NASA Technical Reports Server (NTRS)

    Riddlebaugh, S. M.

    1974-01-01

    A fluidic oscillator was investigated for use in measuring fuel-air ratios in hydrocarbon combustion processes. The oscillator was operated with dry exhaust gas from an experimental combustor burning ASTM A-1 fuel. Tests were conducted with fuel-air ratios between 0.015 and 0.031. Fuel-air ratios determined by oscillator frequency were within 0.001 of the values computed from separate flow measurements of the air and fuel.

  19. Test methods for determining the suitability of metal alloys for use in oxygen-enriched environments

    NASA Technical Reports Server (NTRS)

    Stoltzfus, Joel M.; Gunaji, Mohan V.

    1991-01-01

    Materials are more flammable in oxygen rich environments than in air. When the structural elements of a system containing oxygen ignite and burn, the results are often catastrophic, causing loss of equipment and perhaps even human lives. Therefore, selection of the proper metallic and non-metallic materials for use in oxygen systems is extremely important. While test methods for the selection of non-metallic materials have been available for years, test methods for the selection of alloys have not been available until recently. Presented here are several test methods that were developed recently at NASA's White Sands Test Facility (WSTF) to study the ignition and combustion of alloys, including the supersonic and subsonic speed particle impact tests, the frictional heating and coefficient of friction tests, and the promoted combustion test. These test methods are available for commercial use.

  20. The characteristics of high temperature air combustion and its practical application to high performance industrial furnace

    SciTech Connect

    Sugiyama, Shunichi; Suzukawa, Yutaka; Hino, Yoshimichi

    1999-07-01

    An experimental regenerative continuous slab reheat furnace was used for the data acquisition of high temperature air combustion. Obtainable preheated air temperature, gas temperature distribution of combustion field, NOx concentration in waste gas, heating pattern, furnace height etc were studied for this purpose. Main results were (1) preheated air temperature close to furnace temperature can be obtained, (2) gas temperature distribution is relatively uniform in main combustion field, (3) NOx concentration in waste gas is significantly reduced, (4) there exists the appropriate combustion capacity of a burner for every furnace width, (5) the optimum furnace height for regenerative continuous slab reheat furnace from the thermal efficiency point of view is lower than the convention one by about 0.5m.

  1. Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

    NASA Technical Reports Server (NTRS)

    Schnauffer, Kurt

    1932-01-01

    The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression ratio and kind of fuel on combustion velocity may be determined. Besides the determination of the influence of the above factors on combustion velocity, the degree of turbulence may also be determined. As a unit of reference in estimating the degree of turbulence, the intake velocity of the charge is chosen.

  2. Waste combustion as a source of ambient air polybrominated diphenylesters (PBDEs)

    EPA Science Inventory

    The first comprehensive set of U.S. data on PBDE concentrations from waste combustion, with more than 40 BDE congeners reported, was compared to ambient air levels of bromodiphenylethers in the U.S. Concentrations of PBDEs were determined in the raw, pre-air pollution control sys...

  3. Combustion of Gaseous Fuels with High Temperature Air in Normal- and Micro-gravity Conditions

    NASA Technical Reports Server (NTRS)

    Wang, Y.; Gupta, A. K.

    2001-01-01

    The objective of this study is determine the effect of air preheat temperature on flame characteristics in normal and microgravity conditions. We have obtained qualitative (global flame features) and some quantitative information on the features of flames using high temperature combustion air under normal gravity conditions with propane and methane as the fuels. This data will be compared with the data under microgravity conditions. The specific focus under normal gravity conditions has been on determining the global flame features as well as the spatial distribution of OH, CH, and C2 from flames using high temperature combustion air at different equivalence ratio.

  4. Development of high temperature air combustion technology in pulverized fossil fuel fired boilers

    SciTech Connect

    Hai Zhang; Guangxi Yue; Junfu Lu; Zhen Jia; Jiangxiong Mao; Toshiro Fujimori; Toshiyuki Suko; Takashi Kiga

    2007-07-01

    High temperature air combustion (HTAC) is a promising technology for energy saving, flame stability enhancement and NOx emission reduction. In a conventional HTAC system, the combustion air is highly preheated by using the recuperative or regenerative heat exchangers. However, such a preheating process is difficult to implement for pulverized fossil fuel fired boilers. In this paper, an alternative approach is proposed. In the proposed HTAC system, a special burner, named PRP burner is introduced to fulfill the preheating process. The PRP burner has a preheating chamber with one end connected with the primary air and the other end opened to the furnace. Inside the chamber, gas recirculation is effectively established such that hot flue gases in the furnace can be introduced. Combustible mixture instead of combustion air is highly preheated by the PRP burner. A series of experiments have been conducted in an industrial scale test facility, burning low volatile petroleum coke and an anthracite coal. Stable combustion was established for burning pure petroleum coke and anthracite coal, respectively. Inside the preheating chamber, the combustible mixture was rapidly heated up to a high temperature level close to that of the hot secondary air used in the conventional HTAC system. The rapid heating of the combustible mixture in the chamber facilitates pyrolysis, volatile matter release processes for the fuel particles, suppressing ignition delay and enhancing combustion stability. Moreover, compared with the results measured in the same facility but with a conventional low NOx burner, NOx concentration at the furnace exit was at the same level when petroleum coke was burnt and 50% less when anthracite was burnt. Practicability of the HTAC technology using the proposed approach was confirmed for efficiently and cleanly burning fossil fuels. 16 refs., 10 figs., 1 tab.

  5. Burning of CP Titanium (Grade 2) in Oxygen-Enriched Atmospheres

    NASA Technical Reports Server (NTRS)

    Stoltzfus, Joel M.; Jeffers, Nathan; Gallus, Timothy D.

    2012-01-01

    The flammability in oxygen-enriched atmospheres of commercially pure (CP) titanium rods as a function of diameter and test gas pressure was determined. Test samples of varying diameters were ignited at the bottom and burned upward in 70% O2/balance N2 and in 99.5+% O2 at various pressures. The burning rate of each ignited sample was determined by observing the apparent regression rate of the melting interface (RRMI) of the burning samples. The burning rate or RRMI increased with decreasing test sample diameter and with increasing test gas pressure and oxygen concentration

  6. Development of fire resistant electronic configurations for use in oxygen enriched environments

    NASA Technical Reports Server (NTRS)

    Smith, F. J.

    1975-01-01

    Design concepts for electronic black boxes and modules were tested in oxygen enriched atmospheres, and it was found that various types of sealed configurations would generally eliminate any flammability hazard. The type of configuration and its construction was found to be of more importance in the elimination of flammability hazards in electronic configurations than the types of materials utilized in them. The design concepts developed for fire hazard free electronic configurations for use in manned space programs are applicable for the design of electronic hardware for any use or environment.

  7. Flammability and sensitivity of materials in oxygen-enriched atmospheres; Proceedings of the Fourth International Symposium, Las Cruces, NM, Apr. 11-13, 1989. Volume 4

    NASA Technical Reports Server (NTRS)

    Stoltzfus, Joel M. (Editor); Benz, Frank J. (Editor); Stradling, Jack S. (Editor)

    1989-01-01

    The present volume discusses the ignition of nonmetallic materials by the impact of high-pressure oxygen, the promoted combustion of nine structural metals in high-pressure gaseous oxygen, the oxygen sensitivity/compatibility ranking of several materials by different test methods, the ignition behavior of silicon greases in oxygen atmospheres, fire spread rates along cylindrical metal rods in high-pressure oxygen, and the design of an ignition-resistant, high pressure/temperature oxygen valve. Also discussed are the promoted ignition of oxygen regulators, the ignition of PTFE-lined flexible hoses by rapid pressurization with oxygen, evolving nonswelling elastomers for high-pressure oxygen environments, the evaluation of systems for oxygen service through the use of the quantitative fault-tree analysis, and oxygen-enriched fires during surgery of the head and neck.

  8. Characteristics of Gaseous Diffusion Flames with High Temperature Combustion Air in Microgravity

    NASA Technical Reports Server (NTRS)

    Ghaderi, M.; Gupta, A. K.

    2003-01-01

    The characteristics of gaseous diffusion flames have been obtained using high temperature combustion air under microgravity conditions. The time resolved flame images under free fall microgravity conditions were obtained from the video images obtained. The tests results reported here were conducted using propane as the fuel and about 1000 C combustion air. The burner included a 0.686 mm diameter central fuel jet injected into the surrounding high temperature combustion air. The fuel jet exit Reynolds number was 63. Several measurements were taken at different air preheats and fuel jet exit Reynolds number. The resulting hybrid color flame was found to be blue at the base of the flame followed by a yellow color flame. The length and width of flame during the entire free fall conditions has been examined. Also the relative flame length and width for blue and yellow portion of the flame has been examined under microgravity conditions. The results show that the flame length decreases and width increases with high air preheats in microgravity condition. In microgravity conditions the flame length is larger with normal temperature combustion air than high temperature air.

  9. The effect of protein oxidation on hydration and water-binding in pork packaged in an oxygen-enriched atmosphere.

    PubMed

    Delles, Rebecca M; Xiong, Youling L

    2014-06-01

    This study investigated the in situ oxidative process of myofibrillar proteins in boneless pork loin chops (Longissimus lumborum) packaged in an oxygen-enriched atmosphere (HiOx: 80% O2/20% CO2), an air-permeable polyvinylchloride (PVC) overwrap, or a partial vacuum (VP) throughout display at 2°C for up to 14, 7, and 21days, respectively. Samples stored in HiOx were susceptible to lipid (TBARS) and protein (carbonyls, sulfhydryls, and aggregation) oxidation, while samples in PVC and VP showed lesser oxidative changes. Water-holding capacity of raw muscle decreased (P<0.05) when stored in HiOx but not in PVC and VP. Upon salt and phosphate brine marination, HiOx and PVC muscle samples had improved hydration capacity during display compared with non-stored control, but display generally decreased hydration of VP samples. The result was in agreement with myofibril structural changes. Despite the enhanced hydration, HiOx muscle was least capable of withholding moisture upon cooking. PMID:24583326

  10. Numerical Investigation of Hydrogen and Kerosene Combustion in Supersonic Air Streams

    NASA Technical Reports Server (NTRS)

    Taha, A. A.; Tiwari, S. N.; Mohieldin, T. O.

    1999-01-01

    The effect of mixing schemes on the combustion of both gaseous hydrogen and liquid kerosene is investigated. Injecting pilot gaseous hydrogen parallel to the supersonic incoming air tends to maintain the stabilization of the main liquid kerosene, which is normally injected. Also the maximum kerosene equivalence ratio that can maintain stable flame can be increased by increasing the pilot energy level. The wedge flame holding contributes to an increased kerosene combustion efficiency by the generation of shock-jet interaction.

  11. Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

    DOEpatents

    Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

    2002-01-01

    A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

  12. Application of Oxygen-Enriched Aeration in the Production of Bacitracin by Bacillus licheniformis

    PubMed Central

    Flickinger, M. C.; Perlman, D.

    1979-01-01

    The physiological effects of controlling the dissolved oxygen tension at 0.01, 0.02, and 0.05 atm by the use of oxygen-enriched aeration were investigated during growth and bacitracin production by Bacillus licheniformis ATCC 10716. Up to a 2.35-fold increase in the final antibiotic yield and a 4-fold increase in the rate of bacitracin synthesis were observed in response to O2-enriched aeration. The increase in antibiotic production was accompanied by increased respiratory activity and an increase in the specific productivity of the culture from 1.3 to 3.6 g of antibiotic per g of cell mass produced. Oxygen enrichment of the aeration decreased medium carbohydrate uptake and the maximum specific growth rate of B. licheniformis from 0.6 h−1 to as low as 0.15 h−1, depending upon the level of enrichment and the conditions of oxygen transfer rate (impeller speed). The response of this culture to O2 enrichment suggests that this method of controlling the dissolved oxygen tension for antibiotic-producing cultures may simulate conditions that would occur if the carbon source were fed slowly, as is often employed to optimize antibiotic production. Analysis of the biologically active bacitracins produced by B. licheniformis ATCC 10716 suggested that the ratio of biologically active peptides was not changed by O2 enrichment, nor were any new biologically active compounds formed. Images PMID:34361

  13. Investigation into Oxygen-Enriched Bottom-Blown Stibnite and Direct Reduction

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Luo, Honglin; Qing, Wenqing; Zheng, Yongxing; Yang, Kang; Han, Junwei

    2014-08-01

    The direct oxidation of stibnite (Sb2S3) using a gas mixture of nitrogen-oxygen was investigated in a pilot plant. Steady-state pilot operation of 5 and 10 t/d was normally observed during the pilot test of 100 days, and a cleaning experiment of high-antimony molten slag from oxygen-enriched bottom-blown was tested by direct reduction in a laboratory-scale electric furnace. Autogenous smelting was achieved without adding any other fuel, which guaranteed the feasibility and advantage of oxygen-enriched bottom-blown stibnite. Through analysis and calculation, the sulfur dioxide concentration in offgas was more than 8 pct, which meets the requirement for the preparation of sulfuric acid. In the reduction experiment, the effects of added CaO, the ratio of coal ( ω = actual weight of coal/theoretical weight of coal), and the slag type on the reduction procedure were considered. The residual slag obtained after reduction averaged less than 1 g/ton Au and less than 1 wt pct Sb. The metal phase contained iron less than 3 wt pct, and the recoveries of Au in the metal phase were more than 98 pct. This process shows significant environmental and economic benefits compared with previous processes.

  14. Air-fuel ratio control system for an internal combustion engine

    SciTech Connect

    Nishimura, T.; Suzuki, M.

    1981-09-29

    The air-fuel ratio for an internal combustion engine is controlled at the three stages: (A) when the engine temperature is lower than a first predetermined value, the air-fuel ratio is controlled only by a choke valve, (B) when the engine is at a temperature of the first predetermined value to a second predetermined value, the air-fuel ratio is controlled according to the output signals of engine temperature detecting means, and (C) when the engine temperature is higher than the second predetermined value, the air-fuel ratio is controlled according to the signals from air-fuel ratio detecting means.

  15. Oxy Coal Combustion at the US EPA

    EPA Science Inventory

    Oxygen enriched coal (oxy-coal) combustion is a developing, and potentially a strategically key technology intended to accommodate direct CO2 recovery and sequestration. Oxy-coal combustion is also intended for retrofit application to existing power plants. During oxy-coal comb...

  16. Numerical study of shock-induced combustion in methane-air mixtures

    SciTech Connect

    Yungster, S.; Rabinowitz, M.J. )

    1993-06-01

    The shock-induced combustion of methane-air mixtures in hypersonic flows is investigated using a new reaction mechanism consisting of 19 reacting species and 52 elementary reactions. This reduced model is derived from a full kinetic mechanism via the Detailed Reduction technique. Zero-dimensional computations of several shock-tube experiments are presented first. The reaction mechanism is then combined with a fully implicit Navier-Stokes CFD code to conduct numerical simulations of two-dimensional and axisymmetric shock-induced combustion experiments of stoichiometric methane-air mixtures at a Mach number of M = 6.61. Applications to the ram accelerator concept are also presented. 19 refs.

  17. Air staging and swirl-assisted mixing and combustion of methane and air

    SciTech Connect

    Krass, B.J.; Puri, I.K.

    1996-12-31

    Two-state combustors offer an effective method for the suppression of combustion-generated pollutants. The imposition of swirl on the fuel and/or oxidizer flows causes recirculation which enhances mixing that in turn reduces NO{sub x} (i.e., total nitrogen oxide) formation. The authors investigate the characteristics of a burner that allows for both good mixing through swirl, and staging. Temperature measurements establish the presence of separate rich and lean zones during staging. Relative uniformity of the temperature profiles, and small magnitudes of temperature fluctuations are characteristic of the burner exit. In the burner product can be either dispersed (with no radial swirl-type structure) or concentrated into separate lean and rich regions. High speed video images confirm the swirling of the inner rich flame. The swirl allows interaction of the primary region with the secondary zone, and shears the secondary fuel jets causing further turbulence and vorticity that enhances mixing and prevents hot spots. Under conditions favoring unmixedness, product distribution occurs on relatively thin flamelet sheets that curve and wrinkle due to vorticity. In general, lower fractions of secondary air are beneficial from the perspective of mixing and homogeneity. The emission index of NO{sub x}, i.e., EINO{sub x} values correlate with the relative fractions of primary air. Fluid dynamical effects supersede those related to stoichiometry in the burner. The maximum EINO{sub x} value is lower than typical EINO{sub x} values for jet-type nonpremixed flames. Therefore, the authors conclude that they have successfully designed and characterized a low-NO{sub x} burner.

  18. Technology Solutions Case Study: Combustion Safety for Appliances Using Indoor Air

    SciTech Connect

    2014-05-01

    This case study describes how to assess and carry out the combustion safety procedures for appliances and heating equipment that uses indoor air for combustion in low-rise residential buildings. Only appliances installed in the living space, or in an area freely communicating with the living space, vented alone or in tandem with another appliance are considered here. This document is for inspectors, auditors, and technicians working in homes where energy upgrades are being conducted whether or not air infiltration control is included in the package of measures being applied. In the indoor combustion air case, guidelines summarized here are based on language provided in several of the codes to establish minimum requirements for the space using simplified prescriptive measures. In addition, building performance testing procedures are provided by testing agencies. The codes in combination with the test procedures offer comprehensive combustion safety coverage to address safety concerns, allowing inexperienced residential energy retrofit inspectors to effectively address combustion safety issues and allow energy retrofits to proceed.

  19. Integrated air separation plant-integrated gasification combined cycle power generator

    SciTech Connect

    Allam, R.J.; Topham, A.

    1992-01-21

    This patent describes an integrated gasification combined cycle power generation system, comprising an air separation unit wherein air is compressed, cooled, and separated into an oxygen and nitrogen enriched fractions, a gasification system for generating a fuel gas, an air compressor system for supplying compressed air for use in combusting the fuel gas, a combustion zone for effecting combustion of the compressed air and the fuel gas, and a gas turbine for effecting the generation of power from the resulting combusted gases from the combustion zone in the combined cycle power generation system. It comprises independently compressing feed air to the air separation unit to pressures of from 8 to 20 bar from the compressor system used to compress air for the combustion zone; cryogenically separating the air in the air separation unit having at least one distillation column operating at pressures of between 8 and 20 bar and producing an oxygen enriched fraction consisting of low purity oxygen, and; utilizing at least a portion of the low purity oxygen for effecting gasification of a carbon containing fuel source by partial oxidation in the gasification system and thereby generating a fuel gas stream; removing at least a portion of a nitrogen enriched fraction from the air separation unit and boosting its pressures to a pressure substantially equal to that of the fuel gas stream; and expanding at least another portion of the nitrogen enriched fraction in an expansion engine.

  20. Performance of High Temperature Air Combustion Boiler with Low NOx Emission

    NASA Astrophysics Data System (ADS)

    Kobayashi, Hiromichi; Ito, Yoshihito; Tsuruta, Naoki; Yoshikawa, Kunio

    Thermal performance in the experiments and three-dimensional numerical simulations for a high temperature air combustion boiler where fuel can be efficiently combusted by high temperature preheated air (800°C-1000°C) is examined. The boiler can burn not only natural gas but also low calorific gas (e. g. full gasification gas obtained from coal or wastes). In the boiler, four regenerative burners are installed. This boiler has new features that not only air but also gasification gas is heated up to 900°C, and combination of burners is switched every 15 seconds where two burners are used as inlets of fuel and air and the other two burners are used as outlets of exhaust gas. Natural gas and syngas obtained from coal are burned. The NOx emission for each fuel is less than 50ppm. The heat transfer of three-dimensional calculation is predicted higher than that of experiment.

  1. Recombination of Hydrogen-Air Combustion Products in an Exhaust Nozzle

    NASA Technical Reports Server (NTRS)

    Lezberg, Erwin A.; Lancashire, Richard B.

    1961-01-01

    Thrust losses due to the inability of dissociated combustion gases to recombine in exhaust nozzles are of primary interest for evaluating the performance of hypersonic ramjets. Some results for the expansion of hydrogen-air combustion products are described. Combustion air was preheated up to 33000 R to simulate high-Mach-number flight conditions. Static-temperature measurements using the line reversal method and wall static pressures were used to indicate the state of the gas during expansion. Results indicated substantial departure from the shifting equilibrium curve beginning slightly downstream of the nozzle throat at stagnation pressures of 1.7 and 3.6 atmospheres. The results are compared with an approximate method for determining a freezing point using an overall rate equation for the oxidation of hydrogen.

  2. Computation of H2/air reacting flowfields in drag-reduction external combustion

    NASA Technical Reports Server (NTRS)

    Lai, H. T.

    1992-01-01

    Numerical simulation and analysis of the solution are presented for a laminar reacting flowfield of air and hydrogen in the case of external combustion employed to reduce base drag in hypersonic vehicles operating at transonic speeds. The flowfield consists of a transonic air stream at a Mach number of 1.26 and a sonic transverse hydrogen injection along a row of 26 orifices. Self-sustained combustion is computed over an expansion ramp downstream of the injection and a flameholder, using the recently developed RPLUS code. Measured data is available only for surface pressure distributions and is used for validation of the code in practical 3D reacting flowfields. Pressure comparison shows generally good agreements, and the main effects of combustion are also qualitatively consistent with experiment.

  3. PIC (PRODUCTS OF INCOMPLETE COMBUSTION) FORMATION UNDER PYROLYTIC AND STARVED AIR CONDITIONS

    EPA Science Inventory

    A comprehensive program of laboratory studies based on the non-flame mode of thermal decomposition produced much data on PIC (Products of Incomplete Combustion) formation, primarily under pyrolytic and starved air conditions. Most significantly, laboratory results from non-flame ...

  4. EPA'S STUDY OF THE GENERATION AND CONTROL OF AIR POLLUTANTS FROM THE COMBUSTION OF ORIMULSION

    EPA Science Inventory

    The paper discusses an EPA study of the grneration and control of air pollutants from the combustion of Orimulsion, a high-sulfur liquid petroleum fuel composed of approximately 70% Venezuelan bitumen, 30% water, and trace amounts of surfactant. (NOTE: It is being used as the pri...

  5. Combustion Gas Properties I-ASTM Jet a Fuel and Dry Air

    NASA Technical Reports Server (NTRS)

    Jones, R. E.; Trout, A. M.; Wear, J. D.; Mcbride, B. J.

    1984-01-01

    A series of computations was made to produce the equilibrium temperature and gas composition for ASTM jet A fuel and dry air. The computed tables and figures provide combustion gas property data for pressures from 0.5 to 50 atmospheres and equivalence ratios from 0 to 2.0.

  6. Combustion gas properties. Part 3: Hydrogen gas fuel and dry air

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Jones, R. E.; Mcbride, B. J.; Beyerle, R. A.

    1985-01-01

    A series of computations has been made to produce the equilibrium temperature and gas composition for hydrogen gas fuel and dry air. The computed tables and figures provide combustion gas property data for pressures from 0.5 to 50 atmospheres and equivalence ratios from 0 to 2.0. Only sample tables and figures are provided in this report.

  7. Air pollution from aircraft. [jet exhaust - aircraft fuels/combustion efficiency

    NASA Technical Reports Server (NTRS)

    Heywood, J. B.; Chigier, N. A.

    1975-01-01

    A model which predicts nitric oxide and carbon monoxide emissions from a swirl can modular combustor is discussed. A detailed analysis of the turbulent fuel-air mixing process in the swirl can module wake region is reviewed. Hot wire anemometry was employed, and gas sampling analysis of fuel combustion emissions were performed.

  8. HAZARDOUS AIR POLLUTANTS FROM THE COMBUSTION OF AN EMULSIFIED HEAVY FUEL OIL IN A FIRETUBE BOILER

    EPA Science Inventory

    The report gives results of measuring emissions of hazardous air pollutants (HAPs) from the combustion flue gases of a No. 6 fuel oil, both with and without an emulsifying agent, in a 2.5 million Btu/hr (732 kW) firetube boiler with the purpose of determining the impacts of the e...

  9. System and method for conditioning intake air to an internal combustion engine

    SciTech Connect

    Sellnau, Mark C.

    2015-08-04

    A system for conditioning the intake air to an internal combustion engine includes a means to boost the pressure of the intake air to the engine and a liquid cooled charge air cooler disposed between the output of the boost means and the charge air intake of the engine. Valves in the coolant system can be actuated so as to define a first configuration in which engine cooling is performed by coolant circulating in a first coolant loop at one temperature, and charge air cooling is performed by coolant flowing in a second coolant loop at a lower temperature. The valves can be actuated so as to define a second configuration in which coolant that has flowed through the engine can be routed through the charge air cooler. The temperature of intake air to the engine can be controlled over a wide range of engine operation.

  10. Copper contamination effects on hydrogen-air combustion under SCRAMJET (supersonic combustion ramjet) testing conditions

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Berry, G.F.

    1990-01-01

    Two forms of copper catalytic reactions (homogeneous and heterogeneous) in hydrogen flames were found in a literature survey. Hydrogen atoms in flames recombine into hydrogen molecules through catalytic reactions, and these reactions which affect the timing of the combustion process. Simulations of hydrogen flames with copper contamination were conducted by using a modified general chemical kinetics program (GCKP). Results show that reaction times of hydrogen flames are shortened by copper catalytic reactions, but ignition times are relatively insensitive to the reactions. The reduction of reaction time depends on the copper concentration, copper phase, particle size (if copper is in the condensed phase), and initial temperature and pressure. The higher the copper concentration of the smaller the particle, the larger the reduction in reaction time. For a supersonic hydrogen flame (Mach number = 4.4) contaminated with 200 ppm of gaseous copper species, the calculated reaction times are reduced by about 9%. Similar reductions in reaction time are also computed for heterogeneous copper contamination. Under scramjet testing conditions, the change of combustion timing appears to be tolerable (less than 5%) if the Mach number is lower than 3 or the copper contamination is less than 100 ppm. The higher rate the Mach number, the longer the reaction time and the larger the copper catalytic effects. 7 tabs., 8 figs., 34 refs.

  11. Experimental investigation of wood combustion in a fixed bed with hot air.

    PubMed

    Markovic, Miladin; Bramer, Eddy A; Brem, Gerrit

    2014-01-01

    Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignition occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T>220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of the primary air speed, fuel moisture and inert content on the combustion characteristics (ignition rate, combustion rate, ignition front speed and temperature of the reaction zone) is evaluated. The upward combustion concept decouples the drying, devolatilization and burnout phase. In this way the moisture and inert content of the waste have almost no influence on the combustion

  12. Effects of Confinement on Combustion of TNT Explosion Products in Air

    SciTech Connect

    Kuhl, A.L.; Oppenheim, A.K.; Ferguson, R.E.; Reichenback, H.; Neuwald, P.

    2000-02-05

    Turbulent combustion fields established by detonative explosions of TNT in confinements of different sizes are studied by high-resolution numerical simulation, using AMR (Adaptive Mesh Refinement) method. The chambers are filled with nitrogen or air at NPT conditions. In the second case, the detonation products, rich in C and CO, act, upon turbulent mixing with air, as fuel in an exothermic process of combustion, manifested by a distinct pressure rise. It is the evolution in space and time of this dynamic process that formed the principal focus of this study. Our results demonstrate a dominating influence of the size of the enclosure on the burning rate--an effect that cannot be expressed in terms of the classical burning speed. Under such circumstances, combustion is of considerable significance, since it is associated with a calorific value (''heat release'') of an order of 3500 Cal/gm, as compared to 1100 Cal/gm of TNT detonation. The numerical simulations provide considerable insight into the evolution of combustion fields dominated by shock-turbulence interactions. Fuel consumption histories, extracted from the simulations, reveal the dynamic features of the system, represented by the rate of combustion (akin to velocity) and its change (akin to acceleration). Time profiles of the mass fraction consumed fuel are expressed, with a remarkable accuracy, by bi-parametric life functions, whereby the trajectories of these parameters, obtained by differentiation, can be evaluated with precision commensurate with their commanding role in the identification of the dynamic nature of the system.

  13. Analysis of Fuel Vaporization, Fuel-Air Mixing, and Combustion in Integrated Mixer-Flame Holders

    NASA Technical Reports Server (NTRS)

    Deur, J. M.; Cline, M. C.

    2004-01-01

    Requirements to limit pollutant emissions from the gas turbine engines for the future High-Speed Civil Transport (HSCT) have led to consideration of various low-emission combustor concepts. One such concept is the Integrated Mixer-Flame Holder (IMFH). This report describes a series of IMFH analyses performed with KIVA-II, a multi-dimensional CFD code for problems involving sprays, turbulence, and combustion. To meet the needs of this study, KIVA-II's boundary condition and chemistry treatments are modified. The study itself examines the relationships between fuel vaporization, fuel-air mixing, and combustion. Parameters being considered include: mixer tube diameter, mixer tube length, mixer tube geometry (converging-diverging versus straight walls), air inlet velocity, air inlet swirl angle, secondary air injection (dilution holes), fuel injection velocity, fuel injection angle, number of fuel injection ports, fuel spray cone angle, and fuel droplet size. Cases are run with and without combustion to examine the variations in fuel-air mixing and potential for flashback due to the above parameters. The degree of fuel-air mixing is judged by comparing average, minimum, and maximum fuel/air ratios at the exit of the mixer tube, while flame stability is monitored by following the location of the flame front as the solution progresses from ignition to steady state. Results indicate that fuel-air mixing can be enhanced by a variety of means, the best being a combination of air inlet swirl and a converging-diverging mixer tube geometry. With the IMFH configuration utilized in the present study, flashback becomes more common as the mixer tube diameter is increased and is instigated by disturbances associated with the dilution hole flow.

  14. OH(A,X) radicals in microwave plasma-assisted combustion of methane/air

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Fuh, Che; Wang, Chuji; Laser Spectroscopy and Plasma Team

    2014-10-01

    A novel microwave plasma-assisted combustion (PAC) system, which consists of a microwave plasma-assisted combustor, a gas flow control manifold, and a set of optical diagnostic systems, was developed as a new test platform to study plasma enhancement of combustion. Using this system, we studied the state-resolved OH(A,X) radicals in the plasma-assisted combustion and ignition of a methane/air mixture. Experimental results identified three reaction zones in the plasma-assisted combustor: the plasma zone, the hybrid plasma-flame zone, and the flame zone. The OH(A) radicals in the three distinct zones were characterized using optical emission spectroscopy (OES). Results showed a surge of OH(A) radicals in the hybrid zone compared to the plasma zone and the flame zone. The OH(X) radicals in the flame zone were measured using cavity ringdown spectroscopy (CRDS), and the absolute number density distribution of OH(X) was quantified in two-dimension. The effect of microwave argon plasma on combustion was studied with two different fuel/oxidizer injection patterns, namely the premixed methane/air injection and the nonpremixed (separate) methane/air injection. Parameters investigated included the flame geometry, the lean flammability limit, the emission spectra, and rotational temperature. State-resolved OH(A,X) radicals in the PAC of both injection patterns were also compared. This work is supported by the National Science Foundation through the Grant No. CBET-1066486.

  15. Indoor air sampling and mutagenicity studies related to emissions from unvented coal combustion

    SciTech Connect

    Mumford, J.L.; Harris, D.B.; Williams, K.; Chuang, J.C.; Cooke, M.

    1986-07-01

    The purpose of the study is to develop sampling strategies and bioassay methods for indoor air in homes. The work reported here was conducted to prepare for a joint U.S.-China field study in Xuan Wei County, Yunnan Province, southern China, where the residents traditionally burn coal or wood for domestic cooking and heating without flue ventilation. These residents are exposed daily to high levels of combustion smoke and have unusually high lung cancer mortality rates, the women's rate the highest in China, and the men's rate among the highest. The paper reports the chemical and biological characterization of coal emissions from a simulated combustion laboratory.

  16. Combustion characteristics of pulverized coal and air/gas premixed flame in a double swirl combustor

    SciTech Connect

    Kamal, M.M.

    2009-07-01

    An experimental work was performed to investigate the co-firing of pulverized coal and premixed gas/air streams in a double swirl combustor. The results showed that the NOx emissions are affected by the relative rates of thermal NOx formation and destruction via the pyrolysis of the fuel-N species in high temperature fuel-rich zones. Various burner designs were tested in order to vary the temperature history and the residence time across both coal and gas flames inside the furnace. It was found that by injecting the coal with a gas/air mixture as a combined central jet surrounded by a swirled air stream, a double flame envelope develops with high temperature fuel-rich conditions in between the two reaction zones such that the pyrolysis reactions to N{sub 2} are accelerated. A further reduction in the minimum NOx emissions, as well as in the minimum CO concentrations, was reported for the case where the coal particles are fed with the gas/air mixture in the region between the two swirled air streams. On the other hand, allocating the gas/air mixture around the swirled air-coal combustion zone provides an earlier contact with air and retards the NOx reduction mechanism in such a way that the elevated temperatures around the coal particles allow higher overall NOx emissions. The downstream impingement of opposing air jets was found more efficient than the impinging of particle non-laden premixed flames for effective NOx reduction. In both cases, there is an upstream flow from the stagnation region to the coal primary combustion region, but with the case of air impingement, the hot fuel-rich zone develops earlier. The optimum configuration was found by impinging all jets of air and coal-gas/air mixtures that pronounced minimum NOx and CO concentrations of 310 and 480ppm, respectively.

  17. Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals

    SciTech Connect

    Szpunar, C.B.

    1992-09-01

    This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those trace elements specified in the US 1990 Clean Air Act Amendments, by tabulating selected characterization data on various source coals by region, state, and rank. On the basis of measurements by various researchers, this report also identifies those organic compounds likely to be derived from the coal combustion process (although their formation is highly dependent on specific boiler configurations and operating conditions).

  18. Thermodynamic analysis of a seeded magnetogasdynamic combustion plasma

    NASA Astrophysics Data System (ADS)

    Bose, T. K.

    1986-06-01

    A Faraday type magnetogasdynamic (MGD) seeded combustion gas plasma generated by burning fuel gas in air with up to 50 percent oxygen enrichment in stoichiometric ratio to determine the sources of thermodynamic irreversibility has been studied. For preliminary determination of the adiabatic flame temperature at one bar, five different fuel gases are studied, out of which four are derivatives of coal: water gas, Lurgi gas, Koppers-Totzek gas, producer gas, and methane. As seed, cesium, potassium and sodium in seed to fuel gas mass ratio of 0.01 to 0.03 in appropriate compound form are used and the equilibrium composition is calculated at 1 bar and temperature from 1500 to 3000 K by considering 14 species in the mixture. Subsequently, a Mollier enthalpy-entropy chart is produced for water gas burning with 50 percent oxygen enriched air and one percent potassium seed to fuel gas mass ratio in the above temperature range and in the pressure range of 0.01 to 100 bars. Finally, from the thermodynamic analysis it is shown that the electrical power generation per unit length is more and irreversibility due to the ohmic heating is less if the temperature is high.

  19. Utilization of ventilation air methane as a supplementary fuel at a circulating fluidized bed combustion boiler.

    PubMed

    You, Changfu; Xu, Xuchang

    2008-04-01

    Ventilation air methane (VAM) accounts for 60-80% of the total emissions from coal mining activities in China, which is of serious greenhouse gas concerns as well as a waste of valuable fuel sources. This contribution evaluates the use of the VAM utilization methods as a supplementary fuel at a circulating fluidized bed combustion boiler. The paper describes the system design and discusses some potential technical challenges such as methane oxidation rate, corrosion, and efficiency. Laboratory experimentation has shown that the VAM can be burnt completely in circulated fluidized bed furnaces, and the VAM oxidation does not obviously affect the boiler operation when the methane concentration is less than 0.6%. The VAM decreased the incomplete combustion loss for the circulating fluidized bed combustion furnace. The economic benefit from the coal saving insures that the proposed system is more economically feasible. PMID:18505001

  20. Utilization of ventilation air methane as a supplementary fuel at a circulating fluidized bed combustion boiler

    SciTech Connect

    Changfu You; Xuchang Xu

    2008-04-01

    Ventilation air methane (VAM) accounts for 60-80% of the total emissions from underground coal mining activities in China, which is of serious greenhouse gas concerns as well as a waste of valuable fuel sources. This contribution evaluates the use of the VAM utilization methods as a supplementary fuel at a circulating fluidized bed combustion boiler. The paper describes the system design and discusses some potential technical challenges such as methane oxidation rate, corrosion, and efficiency. Laboratory experimentation has shown that the VAM can be burnt completely in circulated fluidized bed furnaces, and the VAM oxidation does not obviously affect the boiler operation when the methane concentration is less than 0.6%. The VAM decreased the incomplete combustion loss for the circulating fluidized bed combustion furnace. The economic benefit from the coal saving insures that the proposed system is more economically feasible. 17 refs., 3 figs., 1 tab.

  1. Modelling and simulation of wood chip combustion in a hot air generator system.

    PubMed

    Rajika, J K A T; Narayana, Mahinsasa

    2016-01-01

    This study focuses on modelling and simulation of horizontal moving bed/grate wood chip combustor. A standalone finite volume based 2-D steady state Euler-Euler Computational Fluid Dynamics (CFD) model was developed for packed bed combustion. Packed bed combustion of a medium scale biomass combustor, which was retrofitted from wood log to wood chip feeding for Tea drying in Sri Lanka, was evaluated by a CFD simulation study. The model was validated by the experimental results of an industrial biomass combustor for a hot air generation system in tea industry. Open-source CFD tool; OpenFOAM was used to generate CFD model source code for the packed bed combustion and simulated along with an available solver for free board region modelling in the CFD tool. Height of the packed bed is about 20 cm and biomass particles are assumed to be spherical shape with constant surface area to volume ratio. Temperature measurements of the combustor are well agreed with simulation results while gas phase compositions have discrepancies. Combustion efficiency of the validated hot air generator is around 52.2 %. PMID:27512625

  2. Oxygen enrichment and its application to life support systems for workers in high-altitude areas

    PubMed Central

    Li, Yongling; Liu, Yingshu

    2014-01-01

    Background: Workers coming from lowland regions are at risk of developing acute mountain sickness (AMS) when working in low oxygen high-altitude areas. Objectives: The aim of this study was to improve the conditions that lead to hypoxia and ensure the safety of the high-altitude workers. We analyzed the influence of low atmospheric pressure on the oxygen enrichment process in high-altitude areas using an engineering method called low-pressure swing adsorption (LPSA). Methods: Fourteen male subjects were screened and divided into three groups by type of oxygen supply system used: (1) oxygen cylinder group; (2) LPSA oxygen dispersal group; and (3) control group. These tests included arterial oxygen saturation (SaO2), pulse rate (PR), breaths per minute (BPM), and blood pressure (BP). Results: The results showed that after supplying oxygen using the LPSA method at the tunnel face, the SaO2 of workers increased; the incidence of acute mountain sickness, PR, and BPM significantly decreased. Conclusions: The LPSA life support system was found to be a simple, convenient, efficient, reliable, and applicable approach to ensure proper working conditions at construction sites in high-altitude areas. PMID:25000108

  3. An Elementary Overview of the Selection of Materials for Service in Oxygen-Enriched Environments

    NASA Technical Reports Server (NTRS)

    Davis, Samuel Eddie

    2012-01-01

    The process for selecting materials for use in oxygen or oxygen-enriched environments is one that continues to be investigated by many industries due to the importance to those industries of oxygen systems. There are several excellent resources available to assist oxygen systems design engineers and end-users, with the most comprehensive being ASTM MNL-36, Safe Use of Oxygen and Oxygen Systems: Handbook for Design, Operation and Maintenance, 2nd Edition. ASTM also makes available several standards for oxygen systems. However, the ASTM publications are extremely detailed, and typically designed for professionals who already possess a working knowledge of oxygen systems. No notable resource exists, whether an ASTM or other organizational publication, which can be used to educate engineers or technicians who have no prior knowledge of the nuances of oxygen system design and safety. This paper will fill the void for information needed by organizations that design or operate oxygen systems. The information in this paper is not new information, but is a concise and easily understood summary of selecting materials for oxygen systems. This paper will serve well as an employee s first introduction to oxygen system materials selection, and probably the employee s first introduction to ASTM.

  4. The sulfur poisoning of the nickel/oxygen-enriched yttria-stabilized zirconia

    NASA Astrophysics Data System (ADS)

    Zhang, Yanxing; Wan, Zhengyang; Yang, Zongxian

    2015-10-01

    The sulfur poisoning properties of the nickel/oxygen-enriched yttria-stabilized zirconia (denoted as Ni/YSZ + O) with or without interface O vacancy are studied using the first-principles method based on density functional theory. The effects of the extra O atom at the subsurface vacancy of Ni/YSZ are focused. It is found that S at the Ni/YSZ + O can diffuse easily away from the interface oxygen to the top Ni layer sites. With the formation of O vacancy at the Ni/YSZ + O interface (denoted as Ni/(YSZ + O)-Ov), the adsorbed S prefers to diffuse back to the Ni/YSZ interface O vacancy. Compared with Ni/YSZ-Ov, the Ni/(YSZ + O)-Ov can effectively not only weaken the S adsorption at the interface O vacancy site, but also improve the diffusion of S out of the interface O vacancy. Therefore, the Ni/YSZ + O can help to alleviate the sulfur poisoning at the interface O vacancy site as compared with the Ni/YSZ.

  5. Numerical study of shock-induced combustion in methane-air mixtures

    NASA Technical Reports Server (NTRS)

    Yungster, Shaye; Rabinowitz, Martin J.

    1993-01-01

    The shock-induced combustion of methane-air mixtures in hypersonic flows is investigated using a new reaction mechanism consisting of 19 reacting species and 52 elementary reactions. This reduced model is derived from a full kinetic mechanism via the Detailed Reduction technique. Zero-dimensional computations of several shock-tube experiments are presented first. The reaction mechanism is then combined with a fully implicit Navier-Stokes computational fluid dynamics (CFD) code to conduct numerical simulations of two-dimensional and axisymmetric shock-induced combustion experiments of stoichiometric methane-air mixtures at a Mach number of M = 6.61. Applications to the ram accelerator concept are also presented.

  6. Numerical study of shock-induced combustion in methane-air mixtures

    SciTech Connect

    Yungster, S.; Rabinowitz, M.J.

    1993-06-01

    The shock-induced combustion of methane-air mixtures in hypersonic flows is investigated using a new reaction mechanism consisting of 19 reacting species and 52 elementary reactions. This reduced model is derived from a full kinetic mechanism via the Detailed Reduction technique. Zero-dimensional computations of several shock-tube experiments are presented first. The reaction mechanism is then combined with a fully implicit Navier-Stokes computational fluid dynamics (CFD) code to conduct numerical simulations of two-dimensional and axisymmetric shock-induced combustion experiments of stoichiometric methane-air mixtures at a Mach number of M = 6.61. Applications to the ram accelerator concept are also presented.

  7. Catalytic Combustion of Propane/Air Mixtures on Platinum

    NASA Technical Reports Server (NTRS)

    Bruno, C.; Walsh, P. M.; Santavicca, D. A.; Sinha, N.; Bracco, F. V.; Yaw, Y.

    1983-01-01

    A honeycomb catalyst of platinum (4.2 kg/cu m loading) over cordierite, with gamma-alumina washcoat, a cross section of 2.4 x 2.4 sq cm, a length of 7.6 cm, and a characteristic channel diameter of 1.4 mm is used as a steady flow reactor. Measurements are made with C3H8/air mixtures at 650 to 800 K inlet temperatures, 110 KPa pressure, 10 to 40 m/s inlet velocity, 0.19 to 0.32 equivalence ratios, and approximately 1.5 mole percent water content. The measured quantities are the substrate tempeature at ten axial locations, the exhaust gas temperature, the exhaust concentrations of CO, CO2, O2, and total hydrocarbons, and the pressure drop across the monolith. The measured quantities are compared with those computed with a two-dimensional steady-state model for axial and radial convection and diffusion of mass, momentum, energy and homogeneous (three overall reactions) and heterogeneous (infinitely fast) reactions. It is found that, under the tested conditions, most of the fuel is converted to CO2 and H2O at the surface. Gas-phase reactions tend rapidly to become more important as the temperature and equivalence ratio are increased and the flow velocity is decreased. Surface fuel conversion is much more rapid than fuel diffusion, resulting in diffusion-controlled oxidation.

  8. High efficiency power generation from coal and wastes utilizing high temperature air combustion technology (Part 2: Thermal performance of compact high temperature air preheater and MEET boiler)

    SciTech Connect

    Iwahashi, Takashi; Kosaka, Hitoshi; Yoshida, Nobuhiro

    1998-07-01

    The compact high temperature air preheater and the MEET boiler, which are critical components of the MEET system, are the direct evolutions of the high temperature air combustion technology. Innovative hardware concept for a compact high temperature air preheater has been proposed, and preliminary experiment using the MEET-I high temperature air preheater based on this concept successfully demonstrated continuous high temperature air generation with almost no temperature fluctuation. A preliminary heat transfer calculation for the MEET boiler showed that regenerative combustion using high temperature air is quite effective for radiative heat transfer augmentation in a boiler, which will lead to significant downsizing of a boiler. The heat transfer characteristics in the MEET boiler were experimentally measured and the heat transfer promotion effect and the uniform heat transfer field were confirmed. Moreover, it was understood that excellent combustion with the low BTU gas of about 3,000 kcal/m{sup 3} was done.

  9. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 4: Compositions corresponding to Rankine temperature schedules in part 3

    NASA Technical Reports Server (NTRS)

    Gordon, S.

    1982-01-01

    The equilibrium compositions corresponding to the thermodynamic and transport combustion properties for a wide range of conditions for the reaction of hydrocarbons with air are presented. The compositions presented correspond to Rankine temperature schedules.

  10. Analytical evaluation of effect of equivalence ratio inlet-air temperature and combustion pressure on performance of several possible ram-jet fuels

    NASA Technical Reports Server (NTRS)

    Tower, Leonard K; Gammon, Benson E

    1953-01-01

    The results of an analytical investigation of the theoretical air specific impulse performance and adiabatic combustion temperatures of several possible ram-jet fuels over a range of equivalence ratios, inlet-air temperatures, and combustion pressures, is presented herein. The fuels include octane-1, 50-percent-magnesium slurry, boron, pentaborane, diborane, hydrogen, carbon, and aluminum. Thermal effects from high combustion temperatures were found to effect considerably the combustion performance of all the fuels. An increase in combustion pressure was beneficial to air specific impulse at high combustion temperatures. The use of these theoretical data in engine operation and in the evaluation of experimental data is described.

  11. Combustion

    NASA Technical Reports Server (NTRS)

    Bulzan, Dan

    2007-01-01

    An overview of the emissions related research being conducted as part of the Fundamental Aeronautics Subsonics Fixed Wing Project is presented. The overview includes project metrics, milestones, and descriptions of major research areas. The overview also includes information on some of the emissions research being conducted under NASA Research Announcements. Objective: Development of comprehensive detailed and reduced kinetic mechanisms of jet fuels for chemically-reacting flow modeling. Scientific Challenges: 1) Developing experimental facilities capable of handling higher hydrocarbons and providing benchmark combustion data. 2) Determining and understanding ignition and combustion characteristics, such as laminar flame speeds, extinction stretch rates, and autoignition delays, of jet fuels and hydrocarbons relevant to jet surrogates. 3) Developing comprehensive kinetic models for jet fuels.

  12. Method of regulating the amount of underfire air for combustion of wood fuels in spreader-stroke boilers

    DOEpatents

    Tuttle, Kenneth L.

    1980-01-01

    A method of metering underfire air for increasing efficiency and reducing particulate emissions from wood-fire, spreader-stoker boilers is disclosed. A portion of the combustion air, approximately one pound of air per pound of wood, is fed through the grate into the fuel bed, while the remainder of the combustion air is distributed above the fuel in the furnace, and the fuel bed is maintained at a depth sufficient to consume all oxygen admitted under fire and to insure a continuous layer of fresh fuel thereover to entrap charred particles inside the fuel bed.

  13. The impacts of combustion emissions on air quality and climate - From coal to biofuels and beyond

    NASA Astrophysics Data System (ADS)

    Gaffney, Jeffrey S.; Marley, Nancy A.

    Combustion processes have inherent characteristics that lead to the release in the environment of both gaseous and particulate pollutants that have primary and secondary impacts on air quality, human health, and climate. The emissions from the combustion of fossil fuels and biofuels and their atmospheric impacts are reviewed here with attention given to the emissions of the currently regulated pollutant gasses, primary aerosols, and secondary aerosol precursors as well as the emissions of non-regulated pollutants. Fuels ranging from coal, petroleum, liquefied petroleum gas (LPG), natural gas, as well as the biofuels; ethanol, methanol, methyl tertiary-butyl ether (MTBE), ethyl tertiary-butyl ether (ETBE), and biodiesel, are discussed in terms of the known air quality and climate impacts of the currently regulated pollutants. The potential importance of the non-regulated emissions of both gasses and aerosols in air quality issues and climate is also discussed with principal focus on aldehydes and other oxygenated organics, polycyclic aromatic hydrocarbons (PAHs), and nitrated organics. The connection between air quality and climate change is also addressed with attention given to ozone and aerosols as potentially important greenhouse species.

  14. Heat transfer analysis for high temperature preheated air combustion in furnace

    SciTech Connect

    Taniguchi, H.; Arai, N.; Kudo, K.; Aoki, K.

    1998-07-01

    The high temperature preheated air combustion system has been recently developed and techniques of heat transfer analysis pose important problems in its application to the industrial field. The three-dimensional simulation has to be introduced, therefore, for the above heat transfer analysis with combustion, fluid flow and heat transfer. Another effort may be introduced to reduce the computing time of heat transfer analysis by means of some simplification in software of chemical simulation, etc. If one has introduced the application of the high temperature preheated air combustion technique in natural gas firing, the non-gray radiation should be applied to each radiant gas of CO{sub 2}, H{sub 2}O, CO or CH{sub 4}, in this analysis. Finally, the authors would like to refer the inverse computation of radiation heat transfer in furnace which has been proposed by one of the authors and another researcher in the United States. If one tries to estimate the performance of an industrial furnace, the heat flux on heating material is the most important factor which has been fixed as input data of computation. Therefore, the heat transfer analysis may be sometimes reversed by fixed data of heat flux and proceeded by trial and error method, in order to obtain the initial condition of heat source and furnace facilities.

  15. Numerical simulation on pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed

    NASA Astrophysics Data System (ADS)

    Zhu, Jianguo; Ouyang, Ziqu; Lu, Qinggang

    2013-06-01

    High temperature air combustion is a prospecting technology in energy saving and pollutants reduction. Numerical simulation on pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed was presented. The down-fired combustor, taken as the calculation domain, has the diameter of 220 mm and the height of 3000 mm. 2 cases with air staging combustion are simulated. Compared the simulation results with experimental data, there is a good agreement. It is found that the combustion model and NOx formation model are applicable to simulate the pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed. The results show that there is a uniform temperature profile along the axis of the down-fired combustor. The NOx emissions are lower than those of ordinary pulverized coal combustion, and the NOx emissions are 390 mg/m3 and 352 mg/m3 in Case 1 and Case 2, respectively. At the range of 300-600 mm below the nozzle, the NO concentration decreases, mainly resulting from some homogeneous reactions and heterogeneous reaction. NO concentration has a little increase at the position of 800 mm below the nozzle as the tertiary air supplied to the combustor at the position of 600 mm below the nozzle.

  16. Theoretical studies of the ignition and combustion of silane-hydrogen-air mixtures

    NASA Technical Reports Server (NTRS)

    Chinitz, W.

    1985-01-01

    A chemical kinetic mechanism is proposed for the combustion of silane-hydrogen-oxygen-nitrogen mixtures in the initial temperature range from 800K to 1250K and pressure range from 0.5 to 1.35 atm. The mechanism yields results which are in agreement with published ignition delay times obtained from shock tube experiments. Comparisons between the results obtained using the proposed mechanism and that of an alternative mechanism reveal that the former predicts appreciably shorter ignition delay times, but a flame blowout envelope which is shifted so as to decrease the stable flame region. Over much of the thermodynamic range examined, the mechanism predicts long reaction times. A three step global mechanism is proposed which closely models the ignition phase of SiH4 - H2 - air combustion; however, the reaction phase is less well reproduced by the global model. The necessity for additional experimental data to further assess the proposed models is stressed.

  17. Hypersonic shock-induced combustion in a hydrogen-air system

    SciTech Connect

    Ahuja, J.K.; Tiwari, S.N.; Singh, D.J.

    1995-01-01

    A numerical study was carried out to investigate the shock-induced combustion in premixed hydrogen-air mixture. The calculations have been carried out for Mach 5.11 and 6.46. The Mach 5.11 case was found to be unsteady with periodic oscillations. The frequency of oscillations was calculated and was found to be in good agreement with the experimentally observed frequency. The Mach 6.46 case was found to be of a very high frequency and very low-amplitude phenomena. Thus it can be considered as macroscopically stable. This supports the existing view that it is possible to stabilize the shock-induced combustion phenomena with sufficient level of overdrive. 16 refs.

  18. Study of effects of injector geometry on fuel-air mixing and combustion

    NASA Technical Reports Server (NTRS)

    Bangert, L. H.; Roach, R. L.

    1977-01-01

    An implicit finite-difference method has been developed for computing the flow in the near field of a fuel injector as part of a broader study of the effects of fuel injector geometry on fuel-air mixing and combustion. Detailed numerical results have been obtained for cases of laminar and turbulent flow without base injection, corresponding to the supersonic base flow problem. These numerical results indicated that the method is stable and convergent, and that significant savings in computer time can be achieved, compared with explicit methods.

  19. Innovative Approaches to Fuel-Air Mixing and Combustion in Airbreathing Hypersonic Engines

    NASA Astrophysics Data System (ADS)

    MacLeod, C.

    This paper describes some innovative methods for achieving enhanced fuel-air mixing and combustion in Scramjet-like spaceplane engines. A multimodal approach to the problem is discussed; this involves using several concurrent methods of forced mixing. The paper concentrates on Electromagnetic Activation (EMA) and Electrostatic Attraction as suitable techniques for this purpose - although several other potential methods are also discussed. Previously published empirical data is used to draw conclusions about the likely effectiveness of the system and possible engine topologies are outlined.

  20. Pyrolysis and combustion of tobacco in a cigarette smoking simulator under air and nitrogen atmosphere.

    PubMed

    Busch, Christian; Streibel, Thorsten; Liu, Chuan; McAdam, Kevin G; Zimmermann, Ralf

    2012-04-01

    A coupling between a cigarette smoking simulator and a time-of-flight mass spectrometer was constructed to allow investigation of tobacco smoke formation under simulated burning conditions. The cigarette smoking simulator is designed to burn a sample in close approximation to the conditions experienced by a lit cigarette. The apparatus also permits conditions outside those of normal cigarette burning to be investigated for mechanistic understanding purposes. It allows control of parameters such as smouldering and puff temperatures, as well as combustion rate and puffing volume. In this study, the system enabled examination of the effects of "smoking" a cigarette under a nitrogen atmosphere. Time-of-flight mass spectrometry combined with a soft ionisation technique is expedient to analyse complex mixtures such as tobacco smoke with a high time resolution. The objective of the study was to separate pyrolysis from combustion processes to reveal the formation mechanism of several selected toxicants. A purposely designed adapter, with no measurable dead volume or memory effects, enables the analysis of pyrolysis and combustion gases from tobacco and tobacco products (e.g. 3R4F reference cigarette) with minimum aging. The combined system demonstrates clear distinctions between smoke composition found under air and nitrogen smoking atmospheres based on the corresponding mass spectra and visualisations using principal component analysis. PMID:22392377

  1. Indoor air sampling and mutagenicity studies of emissions from unvented coal combustion

    SciTech Connect

    Mumford, J.L.; Harris, D.B.; Williams, K.; Chuang, J.C.; Cooke, M.

    1987-03-01

    To develop sampling strategies and bioassay protocols for indoor air containing emissions from coal combustion in homes of the rural Xuan Wei County in China, the authors developed a medium-volume sampler to collect the <10-..mu..m particles and semivolatile organics by a filter and an XAD-2 resin, respectively. A high-volume particulate sampler was used for comparison. The coal was burned under conditions that simulated the open-pit combustion that occurs in Xuan Wei. High-volume and medium-volume sampling yielded similar, high particulate concentrations 38-39 mg/m/sup 3/. Fifteen percent of the total extractable organic mass was collected in the XAD-2 resin, and the remaining 85% was retained in the filter. The polycyclic aromatic hydrocarbons found in the XAD were composed of four or fewer rings. In the Ames Salmonella assay, the XAD sample showed low mutagenic activity, and most of the mutagenic activity was found in the filter. The coal combustion emitted both direct- and indirect-acting mutagens, most of which were frameshift mutagens. 12 references, 2 figures, 3 tables.

  2. Air emission from the co-combustion of alternative derived fuels within cement plants: Gaseous pollutants.

    PubMed

    Richards, Glen; Agranovski, Igor E

    2015-02-01

    Cement manufacturing is a resource- and energy-intensive industry, utilizing 9% of global industrial energy use while releasing more than 5% of global carbon dioxide (CO₂) emissions. With an increasing demand of production set to double by 2050, so too will be its carbon footprint. However, Australian cement plants have great potential for energy savings and emission reductions through the substitution of combustion fuels with a proportion of alternative derived fuels (ADFs), namely, fuels derived from wastes. This paper presents the environmental emissions monitoring of 10 cement batching plants while under baseline and ADF operating conditions, and an assessment of parameters influencing combustion. The experiential runs included the varied substitution rates of seven waste streams and the monitoring of seven target pollutants. The co-combustion tests of waste oil, wood chips, wood chips and plastic, waste solvents, and shredded tires were shown to have the minimal influence when compared to baseline runs, or had significantly reduced the unit mass emission factor of pollutants. With an increasing ADF% substitution, monitoring identified there to be no subsequent emission effects and that key process parameters contributing to contaminant suppression include (1) precalciner and kiln fuel firing rate and residence time; (2) preheater and precalciner gas and material temperature; (3) rotary kiln flame temperature; (4) fuel-air ratio and percentage of excess oxygen; and (5) the rate of meal feed and rate of clinker produced. PMID:25947054

  3. Hazardous air pollutant emissions from gas-fired combustion sources: emissions and the effects of design and fuel type.

    PubMed

    England, G C; McGrath, T P; Gilmer, L; Seebold, J G; Lev-On, M; Hunt, T

    2001-01-01

    Air emissions from gas-fired combustion devices such as boilers, process heaters, gas turbines and stationary reciprocating engines contain hazardous air pollutants (HAPs) subjected to consideration under the federal clean air act (CAA). This work presents a recently completed major research project to develop an understanding of HAP emissions from gas-fired boilers and process heaters and new HAP emission factors based on field emission tests of gas-fired external combustion devices used in the petroleum industry. The effect of combustion system design and operating parameters on HAP emissions determined by both field and research tests are discussed. Data from field tests of gas-fired petroleum industry boilers and heaters generally show very low emission levels of organic HAPs. A comparison of the emission data for boilers and process heaters, including units with and without various forms of NOx emission controls, showed no significant difference in organic HAP emission characteristics due to process or burner design. This conclusion is also supported by the results of research tests with different burner designs. Based on field tests of units fired with natural gas and various petroleum industry process gases and research tests in which gas composition was intentionally varied, organic HAP emissions were not determined to be significantly affected by the gas composition. Research data indicate that elevated organic HAP emission levels are found only under extreme operating conditions (starved air or high excess air combustion) associated with poor combustion. PMID:11219701

  4. Megacity and country emissions from combustion sources-Buenos Aires-Argentina

    NASA Astrophysics Data System (ADS)

    Dawidowski, L.; Gomez, D.; Matranga, M.; D'Angiola, A.; Oreggioni, G.

    2010-12-01

    Historic time series (1970-2006) emissions of greenhouse gases and air pollutants arising from stationary and mobile combustion sources were estimated at national level for Argentina and at regional level for the metropolitan area of Buenos Aires (MABA). All emissions were estimated using a bottom-up approach following the IPCC good practice guidance. For mobile sources, national emissions include all transport categories. Regional emissions account thus far only for on-road. For national emissions, methodologies and guidance by the IPCC were employed, applying the highest possible tier and using: i)country-specific emission factors for carbon and sulphur and technology-based information for other species, ii)activity data from energy balance series (1970-2007), and iii)complementary information concerning the non-energy use of fuels. Regional emissions in 2006 were estimated in-depth using a technology-based approach for the city of Buenos Aires (CBA) and the 24 neighboring districts composing the MABA. A regional emissions factors database was developed to better characterize Latin American fleets and driving conditions employing COPERT III-IV algorithms and emission factors measured in dynamometers and circulating vehicles in Argentina, Brazil, Chile and Colombia. Past emissions were back estimated from 2005 to 1970 using the best available information, which differs greatly among categories, spatial disaggregation and time periods. The time series of stationary and mobile combustion sources at the national and regional level allowed the identification of distinct patterns. National greenhouse gas emissions in 2006 amounted to ~ 150 million ton CO2-equivalent, 70% of which were contributed by stationary sources. On-road transport was the major contributor within mobile sources (28.1 %). The increasing emissions trends are dominated by on-road transport, agriculture and residential categories while the variability is largely associated with energy industries

  5. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 1: Properties in SI units

    NASA Technical Reports Server (NTRS)

    Gordon, S.

    1982-01-01

    Thermodynamic and transport combustion properties were calculated for a wide range of conditions for the reaction of hydrocarbons with air. Three hydrogen-carbon atom ratios (H/C = 1.7, 2.0, 2.1) were selected to represent the range of aircraft fuels. For each of these H/C ratios, combustion properties were calculated for the following conditions: Equivalence ratio: 0, 0.25, 0.5, 0.75, 1.0, 1.25 Water - dry air mass ratio: 0, 0.03 Pressure, kPa: 1.01325, 10.1325, 101.325, 1013.25, 5066.25 (or in atm: 0.01, 0.1, 1, 10, 50) Temperature, K: every 10 degrees from 200 to 900 K; every 50 degrees from 900 to 3000 K Temperature, R: every 20 degrees from 360 to 1600 R; very 100 degrees from 1600 to 5400 R. The properties presented are composition, density, molecular weight, enthalphy, entropy, specific heat at constant pressure, volume derivatives, isentropic exponent, velocity of sound, viscosity, thermal conductivity, and Prandtl number. Property tables are based on composites that were calculated by assuming both: (1) chemical equilibrium (for both homogeneous and heterogeneous phases) and (2) constant compositions for all temperatures. Properties in SI units are presented in this report for the Kelvin temperature schedules.

  6. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 1: Properties in SI units

    NASA Astrophysics Data System (ADS)

    Gordon, S.

    1982-07-01

    Thermodynamic and transport combustion properties were calculated for a wide range of conditions for the reaction of hydrocarbons with air. Three hydrogen-carbon atom ratios (H/C = 1.7, 2.0, 2.1) were selected to represent the range of aircraft fuels. For each of these H/C ratios, combustion properties were calculated for the following conditions: Equivalence ratio: 0, 0.25, 0.5, 0.75, 1.0, 1.25 Water - dry air mass ratio: 0, 0.03 Pressure, kPa: 1.01325, 10.1325, 101.325, 1013.25, 5066.25 (or in atm: 0.01, 0.1, 1, 10, 50) Temperature, K: every 10 degrees from 200 to 900 K; every 50 degrees from 900 to 3000 K Temperature, R: every 20 degrees from 360 to 1600 R; very 100 degrees from 1600 to 5400 R. The properties presented are composition, density, molecular weight, enthalphy, entropy, specific heat at constant pressure, volume derivatives, isentropic exponent, velocity of sound, viscosity, thermal conductivity, and Prandtl number. Property tables are based on composites that were calculated by assuming both: (1) chemical equilibrium (for both homogeneous and heterogeneous phases) and (2) constant compositions for all temperatures. Properties in SI units are presented in this report for the Kelvin temperature schedules.

  7. Uncertainty for data with non-detects: Air toxic emissions from combustion

    SciTech Connect

    Zhao, Y.C.; Frey, H.C.

    2006-12-15

    Air toxic emission factor datasets often contain one or more points below a single or multiple detection limits and such datasets are referred to as 'censored.' Conventional methods used to deal with censored datasets include removing non-detects, replacing the censored points with zero, half of the detection limit, or the detection limit. However, the estimated means of the censored dataset by conventional methods are usually biased. Maximum likelihood estimation (MLE) and bootstrap simulation have been demonstrated as a statistically robust method to quantify variability and uncertainty of censored datasets and can provide asymptotically unbiased mean estimates. The MLE/bootstrap method is applied to 16 cases of censored air toxic emission factors, including benzene, formaldehyde, benzo(a)pyrene, mercury, arsenic, cadmium, total chromium, chromium VI and lead from coal, fuel oil, and/or wood waste external combustion sources. The proportion of censored values in the emission factor data ranges from 4 to 80%. Key factors that influence the estimated uncertainty in the mean of censored data are sample size and inter-unit variability. The largest range of uncertainty in the mean was obtained for the external coal combustion benzene emission factor, with 95 confidence interval of the mean equal to minus 93 to plus 411%.

  8. Review of the PDWA Concept for Combustion Enhancement in a Supersonic Air-Breathing Combustor Environment

    NASA Technical Reports Server (NTRS)

    Canbier, Jean-Luc; Edwards, Thomas A. (Technical Monitor)

    1995-01-01

    This paper reviews the design of the Pulsed Detonation Wave Augmentor (PDWA) concept and the preliminary computational fluid dynamics studies that supported it. The PDWA relies on the rapid generation of detonation waves in a small tube, which are then injected into the supersonic stream of the main combustor. The blast waves thus generated are used to stimulate the mixing and combustion inside the main combustor. The mixing enhancement relies on various forms of the baroclinic interaction, where misaligned pressure and density gradients combine to produce vortical flow. By using unsteady shock waves, the concept also uses the Richtmyer-Meshkov effect to further increase the rate of mixing. By carefully designing the respective configurations of the combustor and the detonation tubes, one can also increase the penetration of the fuel into the supersonic air stream. The unsteady shocks produce lower stagnation pressure losses than steady shocks. Combustion enhancement can also be obtained through the transient shock-heating of the fuel-air interface, and the lowering of the ignition delay in these regions. The numerical simulations identify these processes, and show which configurations give the best results. Engineering considerations are also presented, and discuss the feasibility of the concept. Of primary importance are the enhancements in performance, the design simplicity, the minimization of the power, cost, and weight, and the methods to achieve very rapid cycling.

  9. Microwave plasma jet assisted combustion of premixed methane-air: Roles of OH(A) and OH(X) radicals

    NASA Astrophysics Data System (ADS)

    Wang, Chuji; Wu, Wei

    2013-09-01

    Plasma assisted combustion (PAC) technology can enhance combustion performance by pre-heating combustion fuels, shortening ignition delay time, enhancing flame holding, or increasing flame volume and flame speed. PAC can also increase fuel efficiency by extending fuel lean flammability limit (LFL) and help reduce combustion pollutant emissions. Experiment results have shown that microwave plasma could modify flame structure, increase flame volume, flame speed, flame temperature, and flame stability, and could also extend the fuel lean flammability limit. We report on a novel microwave PAC system that allows us to study PAC using complicated yet well-controlled combinations of operating parameters, such as fuel equivalence ratio (φ) , fuel mixture flow rate, plasma gas flow rate, plasma gases, plasma jet configurations, symmetric or asymmetric fuel-oxidant injection patterns, etc. We have investigated the roles of the stated-resolved OH(A, X) radicals in plasma assisted ignition and combustion of premixed methane-air fuel mixtures. Results suggest that that both the electronically excited state OH(A) and the electronic ground state OH(X) enhance the methane-air ignition process, i.e. extending the fuel LFL, but the flame stabilization and flame holding is primarily determined by the electronic ground state OH(X) as compared to the role of the OH(A). E-mail: cw175@msstate.edu. Supported by National Science Foundation through the grant of ``A quantitative survey of combustion intermediates toward understanding of plasma-assisted combustion mechanism'' (CBET-1066486).

  10. Effect of air-staging on mercury speciation in pulverized fuel co-combustion: part 2

    SciTech Connect

    Shishir P. Sable; Wiebren de Jong; Ruud Meij; Hartmut Spliethoff

    2007-08-15

    The concerns regarding global warming and need for new energy resources brought the concept of biomass and waste as secondary fuels to the power industry. Mercury emissions in cases of cofiring of chicken manure, olive residue, and B-wood with a high volatile bituminous coal blend are studied in the first part of this paper. The use of secondary fuels significantly affects NOx emissions due to different types of nitrogen present in the fuel matrix. Air-staging is a proven in-furnace NOx reduction technology. The present work mainly involves bench scale studies to investigate the effect of air-staging on partitioning of mercury in pulverized fuel co-combustion. The combustion experiments are carried out in an entrained flow reactor at 1300{sup o}C with a 20%th share of secondary fuels. Elemental and total gaseous mercury from the reactor is measured on-line, and ash is analyzed for particulate mercury along with elemental and surface properties. Reducing the air stoichiometry in the primary zone of the combustor increases unburnt carbon which in turn reduces mercury emissions in the gas phase. Ash analysis shows the effect of surface area, particle size, and unburnt carbon on mercury capture. Calcium variation in the ash was observed due to formation of different slag in reducing and oxidizing conditions and might have affected the mercury capture in combination with the above parameters. A low iron concentration of ash does not seem to affect the capture of mercury. The results will help in predicting different forms of mercury emitted from the furnace at desired operating conditions which will eventually form the basis for the design of the control strategies for mercury emissions. 22 refs., 3 figs., 1 tab.

  11. Projections of air toxic emissions from coal-fired utility combustion: Input for hazardous air pollutant regulators

    SciTech Connect

    Szpunar, C.B.

    1993-08-01

    The US Environmental Protection Agency (EPA) is required by the 1990 CAAA to promulgate rules for all ``major`` sources of any of these HAPs. According to the HAPs section of the new Title III, any stationary source emitting 10 tons per year (TPY) of one HAP or 25 TPY of a combination of HAPs will be considered and designated a major source. In contrast to the original National Emission Standards for Hazardous Air Pollutants (NESHAP), which were designed to protect public health to ``an ample margin of safety,`` the new Title III, in its first phase, will regulate by industrial category those sources emitting HAPs in excess of the 10/25-TPY threshold levels, regardless of health risks. The trace elements normally associated with coal mineral matter and the various compounds formed during coal combustion have the potential to produce hazardous air toxic emissions from coal-fired electric utilities. Under Title III, the EPA is required to perform certain studies, prior to any regulation of electric utilities; these studies are currently underway. Also, the US Department of Energy (DOE) maintains a vested interest in addressing those energy policy questions affecting electric utility generation, coal mining, and steel producing critical to this country`s economic well-being, where balancing the costs to the producers and users of energy with the benefits of environmental protection to the workers and the general populace remains of significant concern.

  12. Promoted Combustion Test Data Re-Examined

    NASA Technical Reports Server (NTRS)

    Lewis, Michelle; Jeffers, Nathan; Stoltzfus, Joel

    2010-01-01

    Promoted combustion testing of metallic materials has been performed by NASA since the mid-1980s to determine the burn resistance of materials in oxygen-enriched environments. As the technolo gy has advanced, the method of interpreting, presenting, and applying the promoted combustion data has advanced as well. Recently NASA changed the bum criterion from 15 cm (6 in.) to 3 cm (1.2 in.). This new burn criterion was adopted for ASTM G 124, Standard Test Method for Determining the Combustion Behavior- of Metallic Materials in Oxygen-Enriched Atmospheres. Its effect on the test data and the latest method to display the test data will be discussed. Two specific examples that illustrate how this new criterion affects the burn/no-bum thresholds of metal alloys will also be presented.

  13. Computer program for obtaining thermodynamic and transport properties of air and products of combustion of ASTM-A-1 fuel and air

    NASA Technical Reports Server (NTRS)

    Hippensteele, S. A.; Colladay, R. S.

    1978-01-01

    A computer program for determining desired thermodynamic and transport property values by means of a three-dimensional (pressure, fuel-air ratio, and either enthalpy or temperature) interpolation routine was developed. The program calculates temperature (or enthalpy), molecular weight, viscosity, specific heat at constant pressure, thermal conductivity, isentropic exponent (equal to the specific heat ratio at conditions where gases do not react), Prandtl number, and entropy for air and a combustion gas mixture of ASTM-A-1 fuel and air over fuel-air ratios from zero to stoichiometric, pressures from 1 to 40 atm, and temperatures from 250 to 2800 K.

  14. Opposed jet burner studies of hydrogen combustion with pure and N2, NO-contaminated air

    NASA Technical Reports Server (NTRS)

    Guerra, Rosemary; Pellett, Gerald L.; Northam, G. Burton; Wilson, Lloyd G.

    1987-01-01

    A counterflow diffusion flame formed by an argon-bathed tubular-opposed jet burner (OJB) was used to determine the 'blowoff' and 'restore' combustion characteristics for jets of various H2/N2 mixtures and for jets of air contaminated by NO (which normally occurs in high-enthalpy airflows supplied to hypersonic test facilities for scramjet combustors). Substantial divergence of 'blowoff' and 'restore' limits occurred as H2 mass flux, M(H)2, increased, the H2 jet became richer, and the M(air)/M(H2 + N2) ratio increased from 1 to 3 (molar H2/O2 from 1 to 16). Both OJB limits were sensitive to reactant composition. One to six percent NO in air led to significant N2-corrected decreases in the M(H2) values for 'blowoff' (2-8 percent) and 'restore' (6-12 percent) for mole fractions of H2 ranging from 0.5 to 0.95. However, when H2/O2 was held constant, all N2-corrected changes in M(H2) were negligible.

  15. Indoor air quality scenario in India-An outline of household fuel combustion

    NASA Astrophysics Data System (ADS)

    Rohra, Himanshi; Taneja, Ajay

    2016-03-01

    Most of the research around the world has been on outdoor air pollution, but in India we have a more severe problem of Indoor Air Pollution (IAP). The foremost factor cited for is burning of fossil fuels for cooking. Among the 70% of the country's rural population, about 80% households rely on biomass fuel making India to top the list of countries with largest population lacking access to cleaner fuel for cooking. 4 million deaths and 5% disability-adjusted life-years is an upshot of exposure to IAP from unhealthy cooking making it globally the most critical environmental risk factor. India alone bears the highest burden (28% needless deaths) among developing countries. Moreover, about ¼ of ambient PM2.5 in the country comes from household cookfuels. These considerations have prompted the discussion of the present knowledge on the disastrous health effects of pollutants emitted by biomass combustion in India. Additionally, Particulate Matter as an indoor air pollutant is highlighted with main focus on its spatial temporal variation and some recent Indian studies are further explored. As there are no specific norms for IAP in India, urgent need has arisen for implementing the strategies to create public awareness. Moreover improvement in ventilation and modification in the pattern of fuel will also contribute to eradicate this national health issue.

  16. An analytical study of the hydrogen-air reaction mechanism with application to scramjet combustion

    NASA Technical Reports Server (NTRS)

    Jachimowski, Casimir J.

    1988-01-01

    A chemical kinetic mechanism for the combustion of hydrogen has been assembled and optimized by comparing the observed behavior as determined in shock tube and flame studies with that predicted by the mechanism. The reactions contained in the mechanism reflect the current state of knowledge of the chemistry of the hydrogen/air system, and the assigned rate coefficients are consistent with accepted values. It was determined that the mechanism is capable of satisfactorily reproducing the experimental results for a range of conditions relevant to scramjet combustion. Calculations made with the reaction mechanism for representative scramjet combustor conditions at Mach 8, 16, and 25 showed that chemical kinetic effects can be important and that combustor models which use nonequilibrium chemistry should be used in preference to models that assume equilibrium chemistry. For the conditions examined the results also showed the importance of including the HO2 chemistry in the mechanism. For Mach numbers less than 16, the studies suggest that an ignition source will most likely be required to overcome slow ignition chemistry. At Mach 25, the initial temperature and pressure was high enough that ignition was rapid and the presence of an ignition source did not significantly affect reaction rates.

  17. Interaction of the burning spherical droplets in oxygen-enriched turbulent environment

    SciTech Connect

    Cho, Chong Pyo; Kim, Ho Young; Yoon, Sam S.

    2009-01-15

    Three-dimensional numerical studies on the interaction of vaporizing and burning droplets were conducted to understand the burning characteristics of multiple droplets in a turbulent environment. The burning droplets characteristics, such as lifetime, surface temperature, vaporization, reaction, and burning rate were examined for various oxygen mole-fractions and geometrical arrangements of droplets. Results from a single droplet combustion test were first verified and validated against existing experimental data. Results indicate that turbulent intensity has a moderate effect on droplet burning rate, but not as prominent an effect as the oxygen mole-fraction. At high oxygen mole-fractions, droplet lifetime was short due to enhanced burning. It is shown that evaporation processes of multiple droplets are notably affected by the inter-space distance between droplets both in streamwise and spanwise directions. The burning rate as a function of oxygen mole-fraction and inter-space distance is determined and can be used as a guideline for future studies on spray combustion. (author)

  18. Review of Air Vitiation Effects on Scramjet Ignition and Flameholding Combustion Processes

    NASA Technical Reports Server (NTRS)

    Pellett, G. L.; Bruno, Claudio; Chinitz, W.

    2002-01-01

    This paper offers a detailed review and analysis of more than 100 papers on the physics and chemistry of scramjet ignition and flameholding combustion processes, and the known effects of air vitiation on these processes. The paper attempts to explain vitiation effects in terms of known chemical kinetics and flame propagation phenomena. Scaling methodology is also examined, and a highly simplified Damkoehler scaling technique based on OH radical production/destruction is developed to extrapolate ground test results, affected by vitiation, to flight testing conditions. The long term goal of this effort is to help provide effective means for extrapolating ground test data to flight, and thus to reduce the time and expense of both ground and flight testing.

  19. Numerical Simulation of Turbulent Propane-Air Combustion with Non-Homogeneous Reactants

    NASA Astrophysics Data System (ADS)

    Haworth, D.; Cuenot, B.; Poinsot, T.; Blint, R.

    1998-11-01

    Two-dimensional numerical simulations of turbulent propane-air combustion have been performed including complex chemistry and realistic molecular transport. The aerothermochemical conditions simulated (reactant temperature and pressure, turbulence rms velocity and integral length scale) correspond to conditions at the time of ignition in an automotive gasoline direct-injection reciprocating IC engine at low speed and light load. Both stoichiometric homogeneous reactants and non-homogeneous reactants with fuel-based equivalence ratios ranging from zero to four have been simulated. In the case of non-homogeneous reactants, a primary premixed flame (defined based on disappearance of the propane fuel) is followed by a secondary heat-release zone that is dominated by CO kinetics and turbulent mixing. Beyond a few flame thicknesses behind the primary flame, any remaining fuel has been broken down into carbon monoxide and hydrogen. Quantitative information relevant for modeling turbulent flame propagation through nonhomogeneous reactants has been extracted.

  20. Heat transfer and pressure distributions on hemisphere-cylinders in methane-air combustion products at Mach 7

    NASA Technical Reports Server (NTRS)

    Weinstein, I.

    1973-01-01

    Heat-transfer and pressure distributions were measured over the surfaces of three hemisphere-cylinder models tested at a nominal Mach number of 7 in the Langley 8-foot high-temperature structures tunnel which uses methane-air products of combustion as a test medium. The results showed that the heat-transfer and pressure distributions over the surface of the models were in good agreement with experimental data obtained in air and also with theoretical predictions.

  1. A comprehensive evaluation of the influence of air combustion and oxy-fuel combustion flue gas constituents on Hg(0) re-emission in WFGD systems.

    PubMed

    Ochoa-González, Raquel; Díaz-Somoano, Mercedes; Martínez-Tarazona, M Rosa

    2014-07-15

    This paper evaluates the influence of the main constituents of flue gases from coal combustion (CO2, O2, N2 and water vapor), in air and oxy-fuel combustion conditions on the re-emission of Hg(0) in wet scrubbers. It was observed that the concentration of water vapor does not affect the re-emission of mercury, whereas O2 and CO2 have a notable influence. High concentrations of O2 in the flue gas prevent the re-emission of Hg(0) due to the reaction of oxygen with the metals present in low oxidation states. High concentrations of CO2, which cause a decrease in the pH and the redox potential of gypsum slurries, reduce the amount of Hg(0) that is re-emitted. As a consequence, the high content of CO2 in oxy-fuel combustion may decrease the re-emission of Hg(0) due to the solubility of CO2 in the suspension and the decrease in the pH. It was also found that O2 affects the stabilization of Hg(2+) species in gypsum slurries. The results of this study confirm that the amount of metals present in limestone as well as the redox potential and pH of the slurries in wet desulphurization plants need to be strictly controlled to reduce Hg(0) re-emissions from power plants operating under oxy-fuel combustion conditions. PMID:24887118

  2. Analytical Model for the Diffusion Process in a In-Situ Combustion Tube

    NASA Astrophysics Data System (ADS)

    Gutierrez, Patricia; Reyes, Adrian

    2015-03-01

    The in-situ combustion process (ISC) is basically an air or oxygen enriched gas injection oil recovery process, inside an extraction well. In contrast to a conventional gas injection process, an ISC process consists in using heat to create a combustion front that raises the fuel temperature, decreasing its viscosity, making extraction easier. The oil is taken toward the productor by means of a vigorous gas thrust as well as a water thrust. To improve and enhance this technique in the field wells, it has been widely perform experimental laboratory tests, in which an in-situ combustion tube is designed to simulate the extraction process. In the present work we propose to solve analytically the problem, with a parabolic partial differential equation associated to the convection-diffusion phenomenon, equation which describes the in-situ combustion process. The whole mathematical problem is established by completing this equation with the correspong boundary and initial conditions, the thickness of the combustion zone, flow velocity, and more parameters. The theoretically obtained results are compared with those reported in literature. We further, fit the parameter of our model to the mentioned data taken from the literature.

  3. 78 FR 14457 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines Correction In rule document 2013-01288, appearing on pages 6674-6724 in the issue of...

  4. Experimental and numerical study of premixed hydrogen/air flame propagating in a combustion chamber.

    PubMed

    Xiao, Huahua; Sun, Jinhua; Chen, Peng

    2014-03-15

    An experimental and numerical study of dynamics of premixed hydrogen/air flame in a closed explosion vessel is described. High-speed shlieren cinematography and pressure recording are used to elucidate the dynamics of the combustion process in the experiment. A dynamically thickened flame model associated with a detailed reaction mechanism is employed in the numerical simulation to examine the flame-flow interaction and effect of wall friction on the flame dynamics. The shlieren photographs show that the flame develops into a distorted tulip shape after a well-pronounced classical tulip front has been formed. The experimental results reveal that the distorted tulip flame disappears with the primary tulip cusp and the distortions merging into each other, and then a classical tulip is repeated. The combustion dynamics is reasonably reproduced in the numerical simulations, including the variations in flame shape and position, pressure build-up and periodically oscillating behavior. It is found that both the tulip and distorted tulip flames can be created in the simulation with free-slip boundary condition at the walls of the vessel and behave in a manner quite close to that in the experiments. This means that the wall friction could be unimportant for the tulip and distorted tulip formation although the boundary layer formed along the sidewalls has an influence to a certain extent on the flame behavior near the sidewalls. The distorted tulip flame is also observed to be produced in the absence of vortex flow in the numerical simulations. The TF model with a detailed chemical scheme is reliable for investigating the dynamics of distorted tulip flame propagation and its underlying mechanism. PMID:24486615

  5. Quantifying the impact of residential heating on the urban air quality in a typical European coal combustion region.

    PubMed

    Junninen, Heikki; Mønster, Jacob; Rey, Maria; Cancelinha, Jose; Douglas, Kevin; Duane, Matthew; Forcina, Victtorio; Müller, Anne; Lagler, Fritz; Marelli, Luisa; Borowiak, Annette; Niedzialek, Joanna; Paradiz, Bostian; Mira-Salama, Daniel; Jimenez, Jose; Hansen, Ute; Astorga, Covadonga; Stanczyk, Krzysztof; Viana, Mar; Querol, Xavier; Duvall, Rachelle M; Norris, Gary A; Tsakovski, Stefan; Wåhlin, Peter; Horák, Jiri; Larsen, Bo R

    2009-10-15

    The present investigation, carried out as a case study in a typical major city situated in a European coal combustion region (Krakow, Poland), aims at quantifying the impact on the urban air quality of residential heating by coal combustion in comparison with other potential pollution sources such as power plants, industry, and traffic. Emissions were measured for 20 major sources, including small stoves and boilers, and the particulate matter (PM) was analyzed for 52 individual compounds together with outdoor and indoor PM10 collected during typical winter pollution episodes. The data were analyzed using chemical mass balance modeling (CMB) and constrained positive matrix factorization (CMF) yielding source apportionments for PM10, B(a)P, and other regulated air pollutants namely Cd, Ni, As, and Pb. The results are potentially very useful for planning abatement strategies in all areas of the world, where coal combustion in small appliances is significant. During the studied pollution episodes in Krakow, European air quality limits were exceeded with up to a factor 8 for PM10 and up to a factor 200 for B(a)P. The levels of these air pollutants were accompanied by high concentrations of azaarenes, known markers for inefficient coal combustion. The major culprit for the extreme pollution levels was demonstrated to be residential heating by coal combustion in small stoves and boilers (>50% for PM10 and >90% B(a)P), whereas road transport (<10% for PM10 and <3% for B(a)P), and industry (4-15% for PM10 and <6% for B(a)P) played a lesser role. The indoor PM10 and B(a)P concentrations were at high levels similar to those of outdoor concentrations and were found to have the same sources as outdoors. The inorganic secondary aerosol component of PM10 amounted to around 30%, which for a large part may be attributed to the industrial emission of the precursors SO2 and NOx. PMID:19921921

  6. Influence of specimen size, tray inclination and air flow rate on the emission of gases from biomass combustion

    NASA Astrophysics Data System (ADS)

    Amorim, E. B.; Carvalho, J. A.; Soares Neto, T. G.; Anselmo, E.; Saito, V. O.; Dias, F. F.; Santos, J. C.

    2013-08-01

    Experiments of biomass combustion were performed to determine whether specimen size, tray inclination, or combustion air flow rate was the factor that most affects the emission of carbon dioxide, carbon monoxide, and methane. The chosen biomass was Eucalyptus citriodora, a very abundant species in Brazil, utilized in many industrial applications, including combustion for energy generation. Analyses by gas chromatograph and specific online instruments were used to determine the concentrations of the main emitted gases, and the following figures were found for the emission factors: 1400 ± 101 g kg-1 of CO2, 50 ± 13 g kg-1 of CO, and 3.2 ± 0.5 g kg-1 of CH4, which agree with values published in the literature for biomass from the Amazon rainforest. Statistical analysis of the experiments determined that specimen size most significantly affected the emission of gases, especially CO2 and CO.

  7. Numerical study of hydrogen-air supersonic combustion by using elliptic and parabolized equations

    NASA Technical Reports Server (NTRS)

    Chitsomboon, T.; Tiwari, S. N.

    1986-01-01

    The two-dimensional Navier-Stokes and species continuity equations are used to investigate supersonic chemically reacting flow problems which are related to scramjet-engine configurations. A global two-step finite-rate chemistry model is employed to represent the hydrogen-air combustion in the flow. An algebraic turbulent model is adopted for turbulent flow calculations. The explicit unsplit MacCormack finite-difference algorithm is used to develop a computer program suitable for a vector processing computer. The computer program developed is then used to integrate the system of the governing equations in time until convergence is attained. The chemistry source terms in the species continuity equations are evaluated implicitly to alleviate stiffness associated with fast chemical reactions. The problems solved by the elliptic code are re-investigated by using a set of two-dimensional parabolized Navier-Stokes and species equations. A linearized fully-coupled fully-implicit finite difference algorithm is used to develop a second computer code which solves the governing equations by marching in spce rather than time, resulting in a considerable saving in computer resources. Results obtained by using the parabolized formulation are compared with the results obtained by using the fully-elliptic equations. The comparisons indicate fairly good agreement of the results of the two formulations.

  8. Experimental Behavior of Pentaborane-Air Combustion Products During Expansion in a Convergent Divergent Nozzle

    NASA Technical Reports Server (NTRS)

    Branstetter, J. R.; Setze, P. C.

    1958-01-01

    In order to evaluate the post combustion behavior of boric oxide, pentaborane-air mixtures, burned to completion at a combustor pressure of 3 atmospheres, were expanded through a 7.1-inch-long convergent-divergent nozzle having a 4-inch-diameter throat and an exit-to-throat area ratio of 1.68. The experimentally determined thrust performance was in good agreement with the ideal equilibrium performance at stagnation temperatures of 3300 deg R and lower. The boric oxide vapor at the combustor exit required about 400 F deg supercooling before any condensed phase was observed. For a given thrust, fuel consumption was as much as 20 percent greater than predicted from vapor-pressure data for combustor outlet temperatures i n the vicinity of 3600 deg R. A similar result could be expected in full-scale engines, since the test combustor provided an unusually long dwell time and a highly turbulent environment. During the expansion process, the vapor (when present) did not condense to the extent predicted for an equilibrium expansion process. Moreover, condensation was observed only i n the form of small, abrupt phase changes i n the subsonic flow near the throat. Friction, due to liquid boric oxide films on the nozzle surfaces, was negligible when the surface temperature was above 800 F.

  9. Two dimensional, transient catalytic combustion of CO-air on platinum

    NASA Technical Reports Server (NTRS)

    Sinha, N.; Bruno, C.; Bracco, F. V.

    1985-01-01

    The light off transient of catalytic combustion of lean CO-air mixtures in a platinum coated channel of a honeycomb monolith is studied with a model that resolves transient radial and axial gradients in both the gas and the solid. For the conditions studied it is concluded that: the initial heat release occurs near the entrance at the gas-solid interface and is controlled by heterogeneous reactions; large spatial and temporal temperature gradients occur in the solid near the entrance controlled mostly by the availability of fuel; the temperature of the solid near the entrance achieves almost its steady state value before significant heating of the back; heterogeneous reactions and the gas heated up front and flowing downstream heat the back of the solid; the overall transient time is controlled by the thermal inertia of the solid and by forced convection; radiation significantly influences both transient and steady state particularly near the entrance; the oxidation of CO occurs mostly on the catalyst and becomes diffusion controlled soon into the transient.

  10. Impact of wood combustion for secondary heating and recreational purposes on particulate air pollution in a suburb in Finland.

    PubMed

    Yli-Tuomi, Tarja; Siponen, Taina; Taimisto, R Pauliina; Aurela, Minna; Teinilä, Kimmo; Hillamo, Risto; Pekkanen, Juha; Salonen, Raimo O; Lanki, Timo

    2015-04-01

    Little information is available on the concentrations of ambient fine particles (PM2.5) in residential areas where wood combustion is common for recreational purposes and secondary heating. Further, the validity of central site measurements of PM2.5 as a measure of exposure is unclear. Therefore, outdoor PM2.5 samples were repeatedly collected at a central site and home outdoor locations from a panel of 29 residents in a suburb in Kuopio, Finland. Source apportionment results from the central site were used to estimate the contributions from local sources, including wood combustion, to PM2.5 and absorption coefficient (ABS) at home outdoor locations. Correlations between the central and home outdoor concentrations of PM2.5, ABS, and their local components were analyzed for each home. At the central site, the average PM2.5 was 6.0 μg m(-)(3) during the heating season, and the contribution from wood combustion (16%) was higher than the contribution from exhaust emissions (12%). Central site measurements predicted poorly daily variation in PM2.5 from local sources. In conclusion, wood combustion significantly affects air quality also in areas where it is not the primary heating source. In epidemiological panel studies, central site measurements may not sufficiently capture daily variation in exposure to PM2.5 from local wood combustion. PMID:25734752

  11. A New Type of Steady and Stable, Laminar, Premixed Flame in Ultra-Lean, Hydrogen-Air Combustion

    SciTech Connect

    Grcar, Joseph F; Grcar, Joseph F

    2008-06-30

    Ultra-lean, hydrogen-air mixtures are found to support another kind of laminar flame that is steady and stable beside flat flames and flame balls. Direct numerical simulations are performed of flames that develop into steadily and stably propagating cells. These cells were the original meaning of the word"flamelet'' when they were observed in lean flammability studies conducted early in the development of combustion science. Several aspects of these two-dimensional flame cells are identified and are contrasted with the properties of one-dimensional flame balls and flat flames. Although lean hydrogen-air flames are subject to thermo-diffusive effects, in this case the result is to stabilize the flame rather than to render it unstable. The flame cells may be useful as basic components of engineering models for premixed combustion when the other types of idealized flames are inapplicable.

  12. Internal combustion engine cylinder-to-cylinder balancing with balanced air-fuel ratios

    DOEpatents

    Harris, Ralph E.; Bourn, Gary D.; Smalley, Anthony J.

    2006-01-03

    A method of balancing combustion among cylinders of an internal combustion engine. For each cylinder, a normalized peak firing pressure is calculated as the ratio of its peak firing pressure to its combustion pressure. Each cylinder's normalized peak firing pressure is compared to a target value for normalized peak firing pressure. The fuel flow is adjusted to any cylinder whose normalized peak firing pressure is not substantially equal to the target value.

  13. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 2: Compositions corresponding to Kelvin temperature schedules in part 1

    NASA Technical Reports Server (NTRS)

    Gordon, S.

    1982-01-01

    The equilibrium compositions that correspond to the thermodynamic and transport combustion properties for a wide range of conditions for the reaction of hydrocarbons with air are presented. Initially 55 gaseous species and 3 coin condensed species were considered in the calculations. Only 17 of these 55 gaseous species had equilibrium mole fractions greater than 0.000005 for any of the conditions studied and therefore these were the only ones retained in the final tables.

  14. NO{sub x} emissions of a jet diffusion flame which is surrounded by a shroud of combustion air

    SciTech Connect

    Tran, P.X.; White, F.P.; Mathur, M.P.; Ekmann, J.M.

    1996-08-01

    The present work reports an experimental study on the behavior of a jet flame surrounded by a shroud of combustion air. Measurements focussed on the flame length and the emissions of NO{sub x}, total unburned hydrocarbons, CO{sub 2}, and O{sub 2}. Four different fuel flow rates (40.0, 78.33, 138.33, and 166.6 cm/s), air flow rates up to 2500 cm{sup 3}/s and four different air injector diameters (0.079 cm, 0. 158 cm, 0.237 cm, and 0.316 cm) were used. The shroud of combustion air causes the flame length to decrease by a factor proportional to 1/[p{sub a}/p{sub f} + C{sub 2}({mu}{sub a}Re,a/{mu}{sub f}Re,f){sup 2}]{sup {1/2}}. A substantial shortening of the flame length occurred by increasing the air injection velocity keeping fuel rate fixed or conversely by lowering the fuel flow rate keeping air flow rate constant. NO{sub x} emissions ranging from 5 ppm to 64 ppm were observed and the emission of NO{sub x} decreased strongly with the increased air velocity. The decrease of NO{sub x} emissions was found to follow a similar scaling law as does the flame length. However, the emission of the total hydrocarbons increased with the increased air velocity or the decreased fuel flow rate. A crossover condition where both NO{sub x} and unburned- hydrocarbon emissions are low, was identified. At an air-to-fuel velocity ratio of about 1, the emissions of NO{sub x} and the total hydrocarbons were found to be under 20 ppm.

  15. MERCURY AND AIR TOXIC ELEMENT IMPACTS OF COAL COMBUSTION BY-PRODUCT DISPOSAL AND UTILIZATION

    SciTech Connect

    Debra F. Pflughoeft-Hassett

    2003-07-01

    On April 3, 2003, a project kickoff meeting was held at the U.S. Department of Energy National Energy Technology Laboratory. As a result of this meeting and follow-up communications, a final work plan was developed, and a schedule of laboratory tasks was developed. Work for the remainder of the second quarter of this project focused on sample collection, initiating laboratory tests, and performing literature searchers. The final project partner, the North Dakota Industrial Commission, signed its contract for participation in the project. This effort will focus on the evaluation of coal combustion by-products (CCBs) for their potential to release mercury and other air toxic elements under different controlled laboratory conditions and will investigate the release of these same air toxic elements in select disposal and utilization field settings to understand the impact of various emission control technologies. The information collected will be evaluated and interpreted together with past Energy & Environmental Research Center (EERC) data and similar data from other studies. Results will be used to determine if mercury release from CCBs, both as currently produced and produced with mercury and other emission controls in place, is a realistic environmental issue. The proposed work will evaluate the impact of mercury and other air toxics on the disposal and/or utilization of CCBs. The project will provide data on the environmental acceptability of CCBs expected to be produced in systems with emission controls for typical disposal and utilization scenarios. The project will develop baseline information on release mechanisms of select elements in both conventional CCBs and modified or experimental CCBs. The modified or experimental CCBs will be selected to represent CCBs from systems that have improved emission controls. Controlling these emissions has high potential to change the chemical characteristics and environmental performance of CCBs. Development of reliable

  16. Mercury and Air Toxic Element Impacts of Coal Combustion By-Product Disposal and Utilizaton

    SciTech Connect

    David Hassett; Loreal Heebink; Debra Pflughoeft-Hassett; Tera Buckley; Erick Zacher; Mei Xin; Mae Sexauer Gustin; Rob Jung

    2007-03-31

    The University of North Dakota Energy & Environmental Research Center (EERC) conducted a multiyear study to evaluate the impact of mercury and other air toxic elements (ATEs) on the management of coal combustion by-products (CCBs). The ATEs evaluated in this project were arsenic, cadmium, chromium, lead, nickel, and selenium. The study included laboratory tasks to develop measurement techniques for mercury and ATE releases, sample characterization, and release experiments. A field task was also performed to measure mercury releases at a field site. Samples of fly ash and flue gas desulfurization (FGD) materials were collected preferentially from full-scale coal-fired power plants operating both without and with mercury control technologies in place. In some cases, samples from pilot- and bench-scale emission control tests were included in the laboratory studies. Several sets of 'paired' baseline and test fly ash and FGD materials collected during full-scale mercury emission control tests were also included in laboratory evaluations. Samples from mercury emission control tests all contained activated carbon (AC) and some also incorporated a sorbent-enhancing agent (EA). Laboratory release experiments focused on measuring releases of mercury under conditions designed to simulate CCB exposure to water, ambient-temperature air, elevated temperatures, and microbes in both wet and dry conditions. Results of laboratory evaluations indicated that: (1) Mercury and sometimes selenium are collected with AC used for mercury emission control and, therefore, present at higher concentrations than samples collected without mercury emission controls present. (2) Mercury is stable on CCBs collected from systems both without and with mercury emission controls present under most conditions tested, with the exception of vapor-phase releases of mercury exposed to elevated temperatures. (3) The presence of carbon either from added AC or from unburned coal can result in mercury being

  17. Analytical chemical kinetic investigation of the effects of oxygen, hydrogen, and hydroxyl radicals on hydrogen-air combustion

    NASA Technical Reports Server (NTRS)

    Carson, G. T., Jr.

    1974-01-01

    Quantitative values were computed which show the effects of the presence of small amounts of oxygen, hydrogen, and hydroxyl radicals on the finite-rate chemical kinetics of premixed hydrogen-air mixtures undergoing isobaric autoignition and combustion. The free radicals were considered to be initially present in hydrogen-air mixtures at equivalence ratios of 0.2, 0.6, 1.0, and 1.2. Initial mixture temperatures were 1100 K, 1200 K, and 1500 K, and pressures were 0.5, 1.0, 2.0, and 4.0 atm. Of the radicals investigated, atomic oxygen was found to be the most effective for reducing induction time, defined as the time to 5 percent of the total combustion temperature rise. The reaction time, the time between 5 percent and 95 percent of the temperature rise, is not decreased by the presence of free radicals in the initial hydrogen-air mixture. Fuel additives which yield free radicals might be used to effect a compact supersonic combustor design for efficient operation in an otherwise reaction-limited combustion regime.

  18. Properties of Combustion Gases

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Jones, R. E.; Trout, A. M.; Mcbride, B. J.

    1986-01-01

    New series of reports: First report lists data from combustion of ASTM Jet A fuel and dry air; second report presents tables and figures for combustion-gas properties of natural-gas fuel and dry air, and equivalent ratios.

  19. CHARACTERIZATION OF AIR EMISSIONS FROM THE SIMULATED OPEN COMBUSTION OF FIBERGLASS MATERIALS

    EPA Science Inventory

    The report identifies and quantifies a broad range of pollutants that are discharged during small-scale, simulated, open combustion of fiberglass, and reports these emissions relative to the mass of fiberglass material combusted. Two types of fiberglass materials (representing t...

  20. CHARACTERIZATION OF AIR EMISSIONS FROM THE SIMULATED OPEN COMBUSTION OF FIBERGLASS MATERIALS

    EPA Science Inventory

    The report identifies and quantifies a broad range of pollutants that are discharged during small-scale, simulated, open combustion of fiberglass, and reports these emissions relative to the mass of fiberglass material combusted. wo types of fiberglass materials (representing the...

  1. 75 FR 75937 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-07

    ... ignition (CI) reciprocating internal combustion engines (RICE) (75 FR 9648). The final NESHAP for... Stationary Spark Ignition Internal Combustion Engines. 75 FR 32612 (June 8, 2010). In that action, EPA... proposed NESHAP for several categories of existing stationary RICE (74 FR 9698). That proposed rule...

  2. Simulating Combustion

    NASA Astrophysics Data System (ADS)

    Merker, G.; Schwarz, C.; Stiesch, G.; Otto, F.

    The content spans from simple thermodynamics of the combustion engine to complex models for the description of the air/fuel mixture, ignition, combustion and pollutant formation considering the engine periphery of petrol and diesel engines. Thus the emphasis of the book is on the simulation models and how they are applicable for the development of modern combustion engines. Computers can be used as the engineers testbench following the rules and recommendations described here.

  3. A Novel Layered Sedimentary Rocks Structure of the Oxygen-Enriched Carbon for Ultrahigh-Rate-Performance Supercapacitors.

    PubMed

    Zhang, Lin-Lin; Li, Huan-Huan; Shi, Yan-Hong; Fan, Chao-Ying; Wu, Xing-Long; Wang, Hai-Feng; Sun, Hai-Zhu; Zhang, Jing-Ping

    2016-02-17

    In this paper, gelatin as a natural biomass was selected to successfully prepare an oxygen-enriched carbon with layered sedimentary rocks structure, which exhibited ultrahigh-rate performance and excellent cycling stability as supercapacitors. The specific capacitance reached 272.6 F g(-1) at 1 A g(-1) and still retained 197.0 F g(-1) even at 100 A g(-1) (with high capacitance retention of 72.3%). The outstanding electrochemical performance resulted from the special layered structure with large surface area (827.8 m(2) g(-1)) and high content of oxygen (16.215 wt %), which effectively realized the synergistic effects of the electrical double-layer capacitance and pseudocapacitance. Moreover, it delivered an energy density of 25.3 Wh kg(-1) even with a high power density of 34.7 kW kg(-1) and ultralong cycling stability (with no capacitance decay even over 10,000 cycles at 2 A g(-1)) in a symmetric supercapacitor, which are highly desirable for their practical application in energy storage devices and conversion. PMID:26815316

  4. Simultaneous removal of SO{sub 2} and NO from flue gas using 'oxygen-enriched' highly reactive absorbent

    SciTech Connect

    Zhao, Y.; Sun, X.J.; Fang, H.; Liu, F.

    2007-04-15

    Fly ash, industry-grade lime, and an additive, MnO{sub 2} (M), were used to prepare an 'oxygen-enriched' highly reactive absorbent. Experiments of simultaneous desulfurization and denitrification were carried in a flue gas circulating fluidized bed (CFB). The effects of influencing factors were also investigated on the removal efficiencies of desulfurization and denitrification. Removal efficiencies of 95.5% for SO{sub 2} and 64.8% for NO were obtained respectively under the optimal experimental conditions. The component of the spent absorbent was analyzed with chemical analysis methods. The results indicated that more nitrogen species appeared in the spent absorbent except sulfur species. A scanning electron microscope (SEM) and an accessory X-ray energy spectrometer (EDS) were used to observe microproperties of the samples, including fly ash, oxidizing highly reactive absorbent, and spent absorbent. The simultaneous removal mechanism of SO{sub 2} and NO based on this absorbent was proposed according to the experimental results.

  5. Ab initio atomistic thermodynamics study on the sulfur tolerance mechanism of the oxygen-enriched yttria-stabilized zirconia surface

    NASA Astrophysics Data System (ADS)

    Chu, Xingli; Zhang, Yanxing; Li, Shasha; Yang, Zongxian

    2014-04-01

    The first-principles method based on density functional theory (DFT) is used to investigate the reaction mechanism for the adsorption of H2S on the oxygen-enriched yttria-stabilized zirconia (YSZ + O) (111) surface. It is found that the H2S dissociation processes have low energy barriers (< 0.5 eV) and high exothermicities (2.5 eV), and the dissociative S atoms may result in the poisoning of the YSZ + O surface by forming the SO and the hyposulfite (SO22 -) species with very strong bonds to the surface. In addition, using the ab initio atomistic thermodynamics method, the surface regeneration or de-sulfurization process of a sulfur-poisoned (i.e. sulfur-covered) YSZ + O(111) surface is studied. According to the phase diagram, the adsorbed atomic sulfur can be oxidized to SO2 and removed from the YSZ + O surface by introducing oxidizing reagents, e.g. O2 and H2O.

  6. Nonequilibrium Sulfur Capture and Retention in an Air cooled Slagging Coal Combustion.

    SciTech Connect

    Zauderer, B.

    1997-04-14

    Calcium oxide sorbents injected in a slagging combustor react with the sulfur released during coal combustion to form sulfur bearing particles, some of which are deposited on the liquid slag layer on the combustor wall. Since the solubility of sulfur in liquid slag is low, the slag must be drained from the combustor to limit sulfur re-evolution into the gas phase. The objective of this 24 month project is to perform a series of 16 one day tests to determine the factors that control the retention of the sulfur in the slag that is drained from the combustor. The last of the 16 tests planned for this project was completed in the present reporting period. This was the first test in this project that validated one of the primary hypothesis of this project, namely to retain substantial quantities of sulfur in slag requires high slag mass flow rate. Previous attempts to achieve high sulfur retention with artificial slag met limited success. In this, the 16th test, a high, 37%, ash Indian coal was injected into Coal Tech`s 20 MMBtu/hr air cooled, slagging combustor with gypsum, CaSO{sub 4} (2H{sub 2}O). The slag analysis showed that 20% of the sulfur in the gypsum remained in the slag. This is double the highest sulfur concentration in slag measured in numerous test operations with this combustor. While the test results to date have met the objectives of this project, further high slag mass flow rate tests are planned with the Indian coal to optimize sulfur retention in slag.

  7. Thermodynamic and transport properties of air and its products of combustion with ASTMA-A-1 fuel and natural gas at 20, 30, and 40 atmospheres

    NASA Technical Reports Server (NTRS)

    Poferl, D. J.; Svehla, R. A.

    1973-01-01

    The isentropic exponent, molecular weight, viscosity, specific heat at constant pressure, thermal conductivity, Prandtl number, and enthalpy were calculated for air, the combustion products of ASTM-A-1 jet fuel and air, and the combustion products of natural gas and air. The properties were calculated over a temperature range from 300 to 2800 K in 100 K increments and for pressures of 20, 30 and 40 atmospheres. The data for natural gas and ASTM-A-1 were calculated for fuel-air ratios from zero to stoichiometric in 0.01 increments.

  8. Hybrid membrane--PSA system for separating oxygen from air

    DOEpatents

    Staiger, Chad L.; Vaughn, Mark R.; Miller, A. Keith; Cornelius, Christopher J.

    2011-01-25

    A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc . . . ) and represents a significant advance compared to current technologies.

  9. Experimental study on premixed CH{sub 4}/air mixture combustion in micro Swiss-roll combustors

    SciTech Connect

    Zhong, Bei-Jing; Wang, Jian-Hua

    2010-12-15

    Excess enthalpy combustion is a promising approach to stabilize flame in micro-combustors. Using a Swiss-roll combustor configuration, excess enthalpy combustion can be conveniently achieved. In this work, three types of Swiss-roll combustors with double spiral-shaped channels were designed and fabricated. The combustors were tested using methane/air mixtures of various equivalence ratios. Both temperature distributions and extinction limits were determined for each combustor configuration at different methane mass flow rates. Results indicate that the Swiss-roll combustors developed in the current study greatly enhance combustion stability in center regions of the combustors. At the same time, excess enthalpy combustors of the Swiss-roll configuration significantly extend the extinction limits of methane/air mixtures. In addition, the effects of combustor configurations and thermal insulation arrangements on temperature distributions and extinction limits were evaluated. With heat losses to the environment being significant, the use of thermal insulations further enhances the flame stability in center regions of the Swiss-roll combustors and extends flammable ranges. (author)

  10. Air-fuel ratio control system for internal combustion engines capable of controlling air-fuel ratio in accordance with degree of warming-up of the engines

    SciTech Connect

    Hibino, Y.; Fukuzawa, T.

    1988-06-28

    This patent describes an air-fuel ratio control system for an internal combustion engine, the system having an automatic choke valve arranged in an intake passage of the engine, and exhaust gas sensor arranged in an exhaust passage of the engine and having an output characteristic linear with respect to the concentration of a specific component in exhaust gases from the engine, an air passage bypassing a throttle valve in the intake passage, an air-fuel ratio control valve arranged in the air passage, and disposed to be driven in response to an output from the exhaust gas sensor for controlling the air-fuel ratio of a mixture supplied to the engine, and temperature sensing means for sensing the degree of warming-up of the engine, the combination comprising; determining means for determining whether the exhaust gas has been activated; means for controlling the opening of the automatic choke valve in response to the degree of warming-up of the engine sensed by the temperature sensing means while the determining means determines that the exhaust gas sensor is inactive; means for determining the difference between a desired value of the air-fuel ratio and an actual value thereof sensed by the exhaust gas sensor, and for driving the automatic choke valve when the determined difference is larger than a predetermined value, and the air-fuel ratio control valve when the determined difference is smaller than the predetermined value, respectively, from the time the determining means determines for the first time that the exhaust gas sensor has become activated to the time the temperature sensing means detects completion of warming up of the engine; and means for driving the air-fuel ratio control valve in response to operating conditions of the engine so as to achieve a desired value of the air-fuel ratio, after the temperature sensing means detects completion of warming-up of the engine.

  11. Combustion of hydrogen-air jets in local chemical equilibrium: A guide to the CHARNAL computer program

    NASA Technical Reports Server (NTRS)

    Spalding, D. B.; Launder, B. E.; Morse, A. P.; Maples, G.

    1974-01-01

    A guide to a computer program, written in FORTRAN 4, for predicting the flow properties of turbulent mixing with combustion of a circular jet of hydrogen into a co-flowing stream of air is presented. The program, which is based upon the Imperial College group's PASSA series, solves differential equations for diffusion and dissipation of turbulent kinetic energy and also of the R.M.S. fluctuation of hydrogen concentration. The effective turbulent viscosity for use in the shear stress equation is computed. Chemical equilibrium is assumed throughout the flow.

  12. Modification of NASA Langley 8 foot high temperature tunnel to provide a unique national research facility for hypersonic air-breathing propulsion systems

    NASA Technical Reports Server (NTRS)

    Kelly, H. N.; Wieting, A. R.

    1984-01-01

    A planned modification of the NASA Langley 8-Foot High Temperature Tunnel to make it a unique national research facility for hypersonic air-breathing propulsion systems is described, and some of the ongoing supporting research for that modification is discussed. The modification involves: (1) the addition of an oxygen-enrichment system which will allow the methane-air combustion-heated test stream to simulate air for propulsion testing; and (2) supplemental nozzles to expand the test simulation capability from the current nominal Mach number to 7.0 include Mach numbers 3.0, 4.5, and 5.0. Detailed design of the modifications is currently underway and the modified facility is scheduled to be available for tests of large scale propulsion systems by mid 1988.

  13. Modification of NASA Langley 8 Foot High Temperature Tunnel to provide a unique national research facility for hypersonic air-breathing propulsion systems

    NASA Technical Reports Server (NTRS)

    Kelly, H. N.; Wieting, A. R.

    1984-01-01

    A planned modification of the NASA Langley 8-Foot High Temperature Tunnel to make it a unique national research facility for hypersonic air-breathing propulsion systems is described, and some of the ongoing supporting research for that modification is discussed. The modification involves: (1) the addition of an oxygen-enrichment system which will allow the methane-air combustion-heated test stream to simulate air for propulsion testing; and (2) supplemental nozzles to expand the test simulation capability from the current nominal Mach number to 7.0 include Mach numbers 3.0, 4.5, and 5.0. Detailed design of the modifications is currently underway and the modified facility is scheduled to be available for tests of large scale propulsion systems by mid 1988.

  14. Effects of percentage of blockage and flameholder downstream counterbores on lean combustion limits of premixed, prevaporized propane-air mixture

    NASA Technical Reports Server (NTRS)

    Fernandez, M. A. B.

    1983-01-01

    Lean combustion limits were determined for a premixed prevaporized propane air mixture with flat plate flame stabilizers. Experiments were conducted in a constant area flame tube combustor utilizing flameholders of varying percentages of blockage and downstream counterbores. Combustor inlet air velocity at ambient conditions was varied from 4 to 9 meters per second. Flameholders with a center hole and four half holes surrounding it were tested with 63, 73, and 85 percent blockage and counterbore diameters of 112 and 125 percent of the thru hole diameter, in addition to the no counterbore configuration. Improved stability was obtained by using counterbore flameholders and higher percentages of blockage. Increases in mixture velocity caused the equivalence ratio at blowout to increase in all cases.

  15. Mobile Source Air Toxics (MSATs) from High Efficiency Clean Combustion: Catalytic Exhaust Treatment Effects

    SciTech Connect

    Storey, John Morse; Lewis Sr, Samuel Arthur; Parks, II, James E; Barone, Teresa L; Prikhodko, Vitaly Y

    2008-01-01

    High Efficiency Clean Combustion (HECC) strategies such as homogenous charge compression ignition (HCCI) and pre-mixed charge compression ignition (PCCI) offer much promise for the reduction of NOx and PM from diesel engines. While delivering low PM and low NOx, these combustion modes often produce much higher levels of CO and HC than conventional diesel combustion modes. In addition, partially oxygenated species such as formaldehyde (an MSAT) and other aldehydes increase with HECC modes. The higher levels of CO and HCs have the potential to compromise the performance of the catalytic aftertreatment, specifically at low load operating points. As HECC strategies become incorporated into vehicle calibrations, manufacturers need to avoid producing MSATs in higher quantities than found in conventional combustion modes. This paper describes research on two different HECC strategies, HCCI and PCCI. Engine-out data for several MSAT species (formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, xylenes, naphthalene, PAHs, diesel PM) as well as other HC species are presented and compared when possible with conventional operation. In addition, catalyst-out values were measured to assess the destruction of individual MSATs over the catalyst. At low engine loads, MSATs were higher and catalyst performance was poorer. Particle sizing results identify large differences between PM from conventional and HECC operation.

  16. 78 FR 54606 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-05

    ... standards of performance (``NSPS'') for stationary internal combustion engines (ICE) (78 FR 6674). Following... stationary RICE on March 3, 2010, (75 FR 9648) and August 20, 2010 (75 FR 51570). The EPA received petitions... amendments to the RICE NESHAP on January 30, 2013, (78 FR 6674) to address certain issues raised in...

  17. ENVIRONMENTAL CONTROL OF TOXIC METAL AIR EMISSIONS FROM THE COMBUSTION OF COAL AND WASTES

    EPA Science Inventory

    The paper is concerned with the partitioning of toxic metals (e.g., arsenic, selenium, mercury, chromium, lead, and cadmium) during combustion, and with the mitigation of their effect on the environment using high-temperature sorbents. The paper is divided into three parts: (1) t...

  18. Tracer-based laser-induced fluorescence measurement technique for quantitative fuel/air-ratio measurements in a hydrogen internal combustion engine.

    PubMed

    Blotevogel, Thomas; Hartmann, Matthias; Rottengruber, Hermann; Leipertz, Alfred

    2008-12-10

    A measurement technique for the quantitative investigation of mixture formation processes in hydrogen internal combustion engines (ICEs) has been developed using tracer-based laser-induced fluorescence (TLIF). This technique can be employed to fired and motored engine operation. The quantitative TLIF fuel/air-ratio results have been verified by means of linear Raman scattering measurements. Exemplary results of the simultaneous investigation of mixture formation and combustion obtained at an optical accessible hydrogen ICE are shown. PMID:19079454

  19. Exposure risk to carcinogenic PAHs in indoor-air during biomass combustion whilst cooking in rural India

    NASA Astrophysics Data System (ADS)

    Bhargava, Anuj; Khanna, R. N.; Bhargava, S. K.; Kumar, Sushil

    In India, a vast majority of rural household burns unprocessed biomass, as an energy source, to cook food. The biomass is burnt indoors in conventionally homemade clay-stoves, called 'Chulha', which results in the generation of a variety of airborne products along with polycyclic aromatic hydrocarbons (PAHs) in an uncontrolled manner. We report here the concentrations and profile of carcinogenic PAHs, co-sampled with respirable suspended particulate matter, in rural indoors during burning of biomass vis-à-vis liquified petroleum gas as the energy source. There is a limited data on the subject in the literature. The seasonal variation has also been studied. Sampling was done in breathing zone and in surrounding areas concurrent with cooking on chulha. PAHs were extracted in methylene chloride and analyzed over HPLC after column clean up on silica gel. Our study revealed that the concentrations of carcinogenic PAHs were fairly high in breathing zone and in surrounding areas while cooking over chulha in rural India. PAHs concentrations increased substantially during biomass combustion. Concentrations were high during CDC combustion and low during LPG combustion or the non-cooking period. This trend was conserved in both the seasons. Concentrations of total PAHs were greater in winter as compared to summer and greatest in the breathing zone. Di-benz( a,h)anthracene, benzo( k)-fluoranthene and chrysene contributed maximum. Benzo( a)pyrene contributed moderately. Maximum concentrations of indoor air benzo( a)pyrene (>1.5 μg/m 3) were found in breathing zone in winter. The daily exposure to high concentrations of carcinogenic PAHs in indoor air environment while cooking food could be impacting for chronic pulmonary illnesses in rural Indian women.

  20. Influence Analysis of Air Flow Momentum on Concentrate Dispersion and Combustion in Copper Flash Smelting Furnace by CFD Simulation

    NASA Astrophysics Data System (ADS)

    Zhou, Jun; Zhou, Jieming; Chen, Zhuo; Mao, Yongning

    2014-09-01

    The Outokumpu flash smelting process is a very successful technology for copper extraction from sulfide concentrate. Numerical simulation has been used for several decades in the analysis and evaluation of the smelting process. However, significant delay in the particle ignition was found in computations of flash furnaces that had great expansion in their productivity. A study was thereafter carried out to investigate how the gaseous flows influence the particle dispersion and combustion. A momentum ratio was defined to describe the effective portion of the pressure forces caused by the lateral and the vertical gaseous flows. Simulations were carried out with Fluent 6.3 (Fluent Inc. The software package is now known as Ansys Fluent of Ansys Inc.) for cases with different momentum ratios as well as of the same momentum value. A detailed analysis and discussion of influences of the gaseous momentum on the particle dispersion are presented. The result reveals that a large momentum ratio combined with large amount of distribution air is helpful for good particle dispersions and thus quicker combustions. Also the process air is found to perform a constraint influence on the particle dispersions, particularly for those of medium and small sizes.

  1. Spatially and Temporally Resolved Measurements of Velocity in a H2-air Combustion-Heated Supersonic Jet

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Cutler, Andrew D.; Danehy, Paul M.; Gaffney, Richard L.; Baurle, Robert a.

    2009-01-01

    This paper presents simultaneous measurements at multiple points of two orthogonal components of flow velocity using a single-shot interferometric Rayleigh scattering (IRS) technique. The measurements are performed on a large-scale Mach 1.6 (Mach 5.5 enthalpy) H2-air combustion jet during the 2007 test campaign in the Direct Connect Supersonic Combustion Test facility at NASA Langley Research Center. The measurements are performed simultaneously with CARS (Coherent Anti-stokes Raman Spectroscopy) using a combined CARS-IRS instrument with a common path 9-nanosecond pulsed, injection-seeded, 532-nm Nd:YAG laser probe pulse. The paper summarizes the measurements of velocities along the core of the vitiated air flow as well as two radial profiles. The average velocity measurement near the centerline at the closest point from the nozzle exit compares favorably with the CFD calculations using the VULCAN code. Further downstream, the measured axial velocity shows overall higher values than predicted with a trend of convergence at further distances. Larger discrepancies are shown in the radial profiles.

  2. Quantitative Analysis of Spectral Interference of Spontaneous Raman Scattering in High-Pressure Fuel-Rich H2-Air Combustion

    NASA Technical Reports Server (NTRS)

    Kojima, Jun; Nguyen, Quang-Viet

    2004-01-01

    We present a theoretical study of the spectral interferences in the spontaneous Raman scattering spectra of major combustion products in 30-atm fuel-rich hydrogen-air flames. An effective methodology is introduced to choose an appropriate line-shape model for simulating Raman spectra in high-pressure combustion environments. The Voigt profile with the additive approximation assumption was found to provide a reasonable model of the spectral line shape for the present analysis. The rotational/vibrational Raman spectra of H2, N2, and H2O were calculated using an anharmonic-oscillator model using the latest collisional broadening coefficients. The calculated spectra were validated with data obtained in a 10-atm fuel-rich H2-air flame and showed excellent agreement. Our quantitative spectral analysis for equivalence ratios ranging from 1.5 to 5.0 revealed substantial amounts of spectral cross-talk between the rotational H2 lines and the N2 O-/Q-branch; and between the vibrational H2O(0,3) line and the vibrational H2O spectrum. We also address the temperature dependence of the spectral cross-talk and extend our analysis to include a cross-talk compensation technique that removes the nterference arising from the H2 Raman spectra onto the N2, or H2O spectra.

  3. Air toxics evaluation of ABB Combustion Engineering Low-Emission Boiler Systems

    SciTech Connect

    Wesnor, J.D.

    1993-10-26

    The specific goals of the program are to identify air toxic compounds that might be emmitted from the new boiler with its various Air Pollution Control device for APCD alternatives in levels of regulatory concern. For the compounds thought to be of concern, potential air toxic control methodologies will be suggested and a Test Protocol will be written to be used in the Proof of Concept and full scale tests. The following task was defined: Define Replations and Standards; Identify Air Toxic Pollutants of Interest to Interest to Utility Boilers; Assesment of Air Toxic By-Products; State of the Art Assessment of Toxic By-Product Control Technologies; and Test Protocol Definition.

  4. CONTROL OF AIR EMISSIONS FROM HAZARDOUS WASTE COMBUSTION SOURCES: FIELD EVALUATIONS OF PILOT-SCALE AIR POLLUTION CONTROL DEVICES

    EPA Science Inventory

    Pilot scale air pollution control devices supplied by Hydro-Sonic Systems, ETS, Inc., and Vulcan Engineering Company were installed at the ENSCO, Inc. Incinerator in El Dorado, Arkansas, in the spring of 1984. Each of these units treated an uncontrolled slipstream of the incinera...

  5. Model test on underground coal gasification (UCG) with low-pressure fire seepage push-through. Part I: Test conditions and air fire seepage

    SciTech Connect

    Yang, L.H.

    2008-07-01

    The technology of a pushing-through gallery with oxygen-enriched fire-seepage combustion was studied during shaft-free UCG in this article, and the main experiment parameters were probed. The test results were analyzed in depth. The patterns of variation and development were pointed out for the fire source moving speed, temperature field, leakage rate, the expanding diameter for the gasification gallery, and blasting pressure. Test results showed that, with the increase in the wind-blasting volume, the moving velocity for the fire source speeded up, and the average temperature for the gallery continuously rose. Under the condition of oxygen-enriched air blasting, when O{sub 2} contents stood at 90%, the moving speed for the fire source was 4-5 times that of air blasting. In the push-through process, the average leakage rate for the blasting was 82.23%, with the average discharge volume of 3.43 m{sup 3}/h and average gallery diameter of 7.87 cm. With the proceeding of firepower seepage, the extent of dropping for the leakage rate increased rapidly, and the drop rate for the blasting pressure gradually heightened.

  6. Influence of air-staging on the concentration profiles of NH{sub 3} and HCN in the combustion chamber of a CFB boiler burning coal

    SciTech Connect

    Kassman, H.; Karlsson, M.; Aamand, L.E.

    1999-07-01

    The characterization of the concentration profiles of NH{sub 3} and HCN are of great importance for increasing the knowledge of the formation and destruction pathways of NO and N{sub 2}O in a fluidized bed boiler. Further improvements of the sampling methods for the determination of both NH{sub 3} and HCN in the combustion chamber in full-scale CFB boilers are also needed. A gas-sampling probe connected to a Fourier Transform Infrared (FTIR) instrument and a gas-quenching (GQ) probe in which the sample is quenched directly in the probe tip by a circulating trapper solution were used. The FTIR technique is based on analysis of hot combustion gases, whereas the trapper solutions from the GQ probe were analyzed by means of wet chemistry. The tests were performed during coal combustion in a 12 MW CFB boiler, which was operated at three air-staging cases with the addition of limestone for sulfur capture. The concentration profiles of NH{sub 3} and HCN in the combustion chamber showed a different pattern concerning the influence of air-staging. The highest levels of NH{sub 3} were observed during reducing condition (severe air-staging), and the lowest were found under oxidizing conditions (no air-staging). The levels of HCN were much lower than those measured for NH{sub 3}. The highest levels of HCN were observed for reversed air-staging and severe air-staging showed almost no HCN. The potential reactors involving NH{sub 3} and HCN in the combustion chamber as well as the potential measurement errors in each sampling technique are discussed for the three air-staging cases.

  7. 14th congress of combustion by-products and their health effects-origin, fate, and health effects of combustion-related air pollutants in the coming era of bio-based energy sources.

    PubMed

    Weidemann, Eva; Andersson, Patrik L; Bidleman, Terry; Boman, Christoffer; Carlin, Danielle J; Collina, Elena; Cormier, Stephania A; Gouveia-Figueira, Sandra C; Gullett, Brian K; Johansson, Christer; Lucas, Donald; Lundin, Lisa; Lundstedt, Staffan; Marklund, Stellan; Nording, Malin L; Ortuño, Nuria; Sallam, Asmaa A; Schmidt, Florian M; Jansson, Stina

    2016-04-01

    The 14th International Congress on Combustion By-Products and Their Health Effects was held in Umeå, Sweden from June 14th to 17th, 2015. The Congress, mainly sponsored by the National Institute of Environmental Health Sciences Superfund Research Program and the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, focused on the "Origin, fate and health effects of combustion-related air pollutants in the coming era of bio-based energy sources". The international delegates included academic and government researchers, engineers, scientists, policymakers and representatives of industrial partners. The Congress provided a unique forum for the discussion of scientific advances in this research area since it addressed in combination the health-related issues and the environmental implications of combustion by-products. The scientific outcomes of the Congress included the consensus opinions that: (a) there is a correlation between human exposure to particulate matter and increased cardiac and respiratory morbidity and mortality; (b) because currently available data does not support the assessment of differences in health outcomes between biomass smoke and other particulates in outdoor air, the potential human health and environmental impacts of emerging air-pollution sources must be addressed. Assessment will require the development of new approaches to characterize combustion emissions through advanced sampling and analytical methods. The Congress also concluded the need for better and more sustainable e-waste management and improved policies, usage and disposal methods for materials containing flame retardants. PMID:26906006

  8. Effect of Indoor air pollution from biomass and solid fuel combustion on symptoms of preeclampsia/eclampsia in Indian women

    PubMed Central

    Agrawal, S; Yamamoto, S

    2015-01-01

    Available evidence concerning the association between indoor air pollution (IAP) from biomass and solid fuel combustion and preeclampsia/eclampsia is not available in developing countries. We investigated the association between exposure to IAP from biomass and solid fuel combustion and symptoms of preeclampsia/eclampsia in Indian women by analyzing cross-sectional data from India's third National Family Health Survey (NFHS-3, 2005–2006). Self-reported symptoms of preeclampsia/eclampsia during pregnancy such as convulsions (not from fever), swelling of legs, body or face, excessive fatigue or vision difficulty during daylight, were obtained from 39 657 women aged 15–49 years who had a live birth in the previous 5 years. Effects of exposure to cooking smoke, ascertained by type of fuel used for cooking on preeclampsia/eclampsia risk, were estimated using logistic regression after adjusting for various confounders. Results indicate that women living in households using biomass and solid fuels have two times higher likelihood of reporting preeclampsia/eclampsia symptoms than do those living in households using cleaner fuels (OR = 2.21; 95%: 1.26–3.87; P = 0.006), even after controlling for the effects of a number of potentially confounding factors. This study is the first to empirically estimate the associations of IAP from biomass and solid fuel combustion and reported symptoms suggestive of preeclampsia/eclampsia in a large nationally representative sample of Indian women and we observed increased risk. These findings have important program and policy implications for countries such as India, where large proportions of the population rely on polluting biomass fuels for cooking and space heating. More epidemiological research with detailed exposure assessments and clinical measures of preeclampsia/eclampsia is needed in a developing country setting to validate these findings. PMID:25039812

  9. High-Efficiency Low-Dross Combustion System for Aluminum Remelting Reverberatory Furnaces, Project Final Report, July 2005

    SciTech Connect

    Soupos, V.; Zelepouga, S.; Rue, D.

    2005-06-30

    GTI, and its commercial partners, have developed a high-efficiency low-dross combustion system that offers environmental and energy efficiency benefits at lower capital costs for the secondary aluminum industry users of reverberatory furnaces. The high-efficiency low-dross combustion system, also called Self-Optimizing Combustion System (SOCS), includes the flex-flame burner firing an air or oxygen-enriched natural gas flame, a non-contact optical flame sensor, and a combustion control system. The flex-flame burner, developed and tested by GTI, provides an innovative firing process in which the flame shape and velocity can be controlled. The burner produces a flame that keeps oxygen away from the bath surface by including an O2-enriched fuel-rich zone on the bottom and an air-fired fuel-lean zone on the top. Flame shape and velocity can be changed at constant firing rate or held constant over a range of firing conditions. A non-intrusive optical sensor is used to monitor the flame at all times. Information from the optical sensor(s) and thermocouples can be used to control the flow of natural gas, air, and oxygen to the burner as needed to maintain desired flame characteristics. This type of control is particularly important to keep oxygen away from the melt surface and thus reduce dross formation. This retrofit technology decreases fuel usage, increases furnace production rate, lowers gaseous emissions, and reduces dross formation. The highest priority research need listed under Recycled Materials is to turn aluminum process waste into usable materials which this technology accomplishes directly by decreasing dross formation and therefore increasing aluminum yield from a gas-fired reverberatory furnace. Emissions of NOx will be reduced to approximately 0.3 lb/ton of aluminum, in compliance with air emission regulations.

  10. Higher borides and oxygen-enriched Mg-B-O inclusions as possible pinning centers in nanostructural magnesium diboride and the influence of additives on their formation

    NASA Astrophysics Data System (ADS)

    Prikhna, Tatiana; Gawalek, Wolfgang; Savchuk, Yaroslav; Tkach, Vasiliy; Danilenko, Nikolay; Wendt, Michael; Dellith, Jan; Weber, Harold; Eisterer, Michael; Moshchil, Viktor; Sergienko, Nina; Kozyrev, Artem; Nagorny, Peter; Shapovalov, Andrey; Melnikov, Vladimir; Dub, Sergey; Litzkendorf, Doris; Habisreuther, Tobias; Schmidt, Christa; Mamalis, Athanasios; Sokolovsky, Vladimir; Sverdun, Vladimir; Karau, Fridrich; Starostina, Alexandra

    2010-10-01

    The study of high pressure (2 GPa) synthesized MgB 2-based materials allows us to conclude that higher borides (with near MgB 12 stoichiometry) and oxygen-enriched Mg-B-O inclusions can be pinning centers in nanostructural magnesium diboride matrix (with average grain sizes of 15-37 nm). It has been established that additions of Ti or SiC as well as manufacturing temperature can affect the size, amount and distribution of these inclusions in the material structure and thus, influence critical current density. The superconducting behavior of materials with near MgB 12 stoichiometry of matrix is discussed.

  11. Modeling of turbulent supersonic H2-air combustion with a multivariate beta PDF

    NASA Technical Reports Server (NTRS)

    Baurle, R. A.; Hassan, H. A.

    1993-01-01

    Recent calculations of turbulent supersonic reacting shear flows using an assumed multivariate beta PDF (probability density function) resulted in reduced production rates and a delay in the onset of combustion. This result is not consistent with available measurements. The present research explores two possible reasons for this behavior: use of PDF's that do not yield Favre averaged quantities, and the gradient diffusion assumption. A new multivariate beta PDF involving species densities is introduced which makes it possible to compute Favre averaged mass fractions. However, using this PDF did not improve comparisons with experiment. A countergradient diffusion model is then introduced. Preliminary calculations suggest this to be the cause of the discrepancy.

  12. Combustion Tests of Rocket Motor Washout Material: Focus on Air toxics Formation Potential and Asbestos Remediation

    SciTech Connect

    G. C. Sclippa; L. L. Baxter; S. G. Buckley

    1999-02-01

    The objective of this investigation is to determine the suitability of cofiring as a recycle / reuse option to landfill disposal for solid rocket motor washout residue. Solid rocket motor washout residue (roughly 55% aluminum powder, 40% polybutadiene rubber binder, 5% residual ammonium perchlorate, and 0.2-1% asbestos) has been fired in Sandia's MultiFuel Combustor (MFC). The MFC is a down-fired combustor with electrically heated walls, capable of simulating a wide range of fuel residence times and stoichiometries. This study reports on the fate of AP-based chlorine and asbestos from the residue following combustion.

  13. Numerical analysis of reaction-diffusion effects on species mixing rates in turbulent premixed methane-air combustion

    SciTech Connect

    Richardson, E.S.; Grout, R.W.; Chen, J.H.; Sankaran, R.

    2010-03-15

    The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding the role of dilatation and turbulence-chemistry interactions on the progress variable dissipation rate. Compared to the progress variable, the mixing rates of intermediate species is found to be several times greater. The variation of species mixing rates are explained with reference to the structure of one-dimensional premixed laminar flames. According to this analysis, mixing rates are governed by the strong gradients which are imposed by flamelet structures at high Damkoehler numbers. This suggests a modeling approach to estimate the mixing rate of individual species which can be applied, for example, in transported probability density function simulations. Flame-turbulence interactions which modify the flamelet based representation are analyzed. (author)

  14. The promising chemical kinetics for the simulation of propane-air combustion with KIVA-II code

    NASA Technical Reports Server (NTRS)

    Ying, S. J.; Gorla, Rama S. R.; Kundu, Krishna P.

    1993-01-01

    The development of chemical kinetics for the simulation of propane-air combustion with the use of computer code KIVA-II since 1989 is summarized here. In order to let readers understand the general feature well, a brief description of the KIVA-II code, specially related with the chemical reactions is also given. Then the results of recent work with 20 reaction mechanism is presented. It is also compared with the 5 reaction mechanism. It may be expected that the numerical stability of the 20 reaction mechanism is better as compared to that of 5 reaction mechanism, but the CPU time of the CRAY computer is much longer. Details are presented in the paper.

  15. VITRIFICATION OF MUNICIPAL SOLID WASTE COMBUSTION AIR POLLUTION CONTROL RESIDUES USING CORNING, INC. PROCESS

    EPA Science Inventory

    A demonstration was conducted to vitrify municipal solid waste (MSW) combustor air pollution control residue (APC) under the USEPA Municipal Waste Innovative Technology Evaluation Program. uplicate demonstration was conducted using a process developed by Corning Inc. in a cold cr...

  16. Parametric study of shock-induced combustion in a hydrogen air system

    NASA Technical Reports Server (NTRS)

    Ahuja, J. K.; Tiwari, Surendra N.

    1994-01-01

    A numerical parametric study is conducted to simulate shock-induced combustion under various free-stream conditions and varying blunt body diameter. A steady combustion front is established if the free-stream Mach number is above the Chapman-Jouguet speed of the mixture, whereas an unsteady reaction front is established if the free-stream Mach number is below or at the Chapman-Jouguet speed of the mixture. The above two cases have been simulated for Mach 5.11 and Mach 6.46 with a projectile diameter of 15 mm. Mach 5.11, which is an underdriven case, shows an unsteady reaction front, whereas Mach 6.46, which is an overdriven case, shows a steady reaction front. Next for Mach 5. 11 reducing the diameter to 2.5 mm causes the instabilities to disappear, whereas, for Mach 6.46 increasing the diameter of the projectile to 225 mm causes the instabilities to reappear, indicating that Chapman-Jouguet speed is not the only deciding factor for these instabilities to trigger. The other key parameters are the projectile diameter, induction time, activation energy and the heat release. The appearance and disappearance of the instabilities have been explained by the one-dimensional wave interaction model.

  17. Effects of Wet Air and Synthetic Combustion Gas Atmospheres on the Oxidation Behavior of Mo-Si-B Alloys

    SciTech Connect

    Kramer, M.J.; Thom, A.J.; Mandal, P.; Behrani, V.; Akinc, M.

    2003-04-24

    Continuing our work on understanding the oxidation behavior of multiphase composite alloys based on the Mo-Si-B system, we investigated three alloys in the Mo-Si-B system, designated as A1, A2, and A3. The nominal phase assemblages of these alloys are: A1 = Mo{sub 5}Si{sub 3}B{sub x} (T1)-MoSi{sub 2}-MoB, A2 = T1-Mo{sub 5}SiB{sub 2} (T2)-Mo{sub 3}Si, and A3 = Mo-T2-Mo{sub 3}Si. Our previous work showed that for exposures to 1100 C, all alloys formed a protective oxide scale in dry air. Exposures to wet air containing about 150 Torr water promoted the formation of a multiphase layer near the scale/alloy interface composed of Mo and MoO{sub 2}. Interrupted mass loss measurements indicated a near zero mass change. In the present study, isothermal mass measurements were conducted in order to quantitatively determine the oxidation rate constants at 1000 C in both dry and wet air. These measurements are critical for understanding the nature of scale development during the initial exposure, as well as the nature of scale stability during the long-term exposure. Isothermal measurements were also conducted at 1600 C in dry air to make an initial determination of alloy stability with respect to Vision 21 goals. We also conducted alloy oxidation testing in a synthetic oxidizing combustion atmosphere. Alloys were exposed up to 300 hours at 1100 C to a gas mixture having an approximate gas composition of N{sub 2} - 13 CO{sub 2} - 10 H{sub 2}O - 4 O{sub 2}. This gas composition simulates oxidizing flue gas, but does not contain a sulfidizing agent that would also be present in flue gas. The oxidized samples were carefully analyzed by SEM/EDS. This analysis will be discussed to provide an understanding of the role of water vapor and the synthetic combustion atmosphere on the oxidative stability of Mo-Si-B alloys.

  18. Visualization research on high efficiency and low NOx combustion technology with multiple air-staged and large angle counter flow of fuel-rich jet

    NASA Astrophysics Data System (ADS)

    Li, Y. Y.; Li, Y.; Lin, Z. C.; Fan, W. D.; Zhang, M. C.

    2010-03-01

    In this paper, a new technique for tangentially fired pulverized coal boiler, high efficiency and low NOx combustion technology with multiple air-staged and large angle counter flow of fuel-rich jet (ACCT for short), is proposed. Based on traditional air staged and rich-lean combustion technique, a NOx reduction area is introduced through air injection between primary combustion zone and secondary combustion zone. To verify the characters of this technique, experiment with a new developed visualization method, image processing on smog tracing with fractal dimension, is carried out on a cold model of 300 MW furnace designed with this technique. The result shows, compared to injection without counter flow, the center lines of counter flow injection go deeper into the chamber and form a smaller tangential circle, which means the rotating momentum of entire vortex is feebler and the exit gyration is weaker. It also shows that with counter flow, the fractal dimensions of boundary between primary jet and front fire side air is bigger, which means more intense turbulence and better mix. As a conclusion, with fractal dimension, image processing on smog tracing method can be a quantificational, convenient and effective visualization way without disturbing the flow field, and it's also acknowledged that ACCT has the following superiorities: high burn out rate, low NOx emission, stable burning, slagging preventing, and temp-bias reducing.

  19. Outdoor Air Pollution (PM2.5) and Ill-Health Attributable to Residential Wood Combustion in the San Francisco Bay Area

    NASA Astrophysics Data System (ADS)

    Chafe, Z.; Fairley, D.; Smith, K. R.

    2015-12-01

    Residential wood combustion is recognized as a major source of fine particulate (PM2.5) air pollution in the San Francisco Bay Area, especially during the winter heating season. Both indoor and outdoor exposure to air pollution from residential wood combustion negatively impact human health, causing premature deaths and ill-health. Previous research has described the regional impact of wood smoke on air quality. Here, we estimate by county the proportion of ambient (outdoor) PM2.5 air pollution attributable to residential wood combustion in the San Francisco Bay Area. We also explore the implications of residential wood burning emissions for human health in the San Francisco Bay Area, reporting the burden of disease associated with this emission source by county. We also describe differences between counties in wood burning behavior, air pollution levels, and human health effects. The results of this research have relevance for air quality regulation and source abatement prioritization in the San Francisco Bay Area and beyond.

  20. Research Opportunities for Cancer Associated with Indoor Air Pollution from Solid-Fuel Combustion

    EPA Science Inventory

    Background: Indoor air pollution (IAP) derived largely from the use of solid fuels for cooking and heating affects about 3 billion people worldwide, resulting in substantial adverse health outcomes, including cancer. Women and children from developing countries are the most expos...

  1. INDOOR AIR SAMPLING AND MUTAGENICITY STUDIES OF EMISSIONS FROM UNVENTED COAL COMBUSTION (JOURNAL VERSION)

    EPA Science Inventory

    The purpose of the study is to develop sampling strategies and bioassay methods for indoor air in homes, the authors developed a medium-volume sampler to collect the <10 - micrometers particulate matter and semivolatile organics, and used high-volume particulate sampler for compa...

  2. Indoor air exposure to coal and wood combustion emissions associated with a high lung cancer rate in Xuan Wei, China

    SciTech Connect

    Mumford, J.L.; Chapman, R.S.; Harris, D.B.; He, X.Z.; Cac, S.R.

    1989-01-01

    Residents of Xuan Wei County in China have unusually high lung cancer mortality that cannot be attributed to tobacco use or occupational exposure. They are exposed to smoke from unvented, open pit coal or wood fires (often used for cooking and heating). The variation in lung cancer rates among communes within the county suggests that indoor combustion of smoky coal may be the prime determinant of lung cancer. To characterize the air in Xuan Wei homes, samples of the air particles and semivolatile organic compounds were collected from homes located in two communes; one commune has a high rate of lung cancer, and the other has a low rate. Samples collected in the commune where the lung cancer rate is high and where smoky coal is the predominant fuel contained high concentrations of small particles with high organic content; organic extracts of these samples were mutagenic. Samples from homes in the wood-burning commune, which has a low rate of lung cancer, consisted mostly of larger particles of lower organic content and mutagenicity. The smoky coal sample was a mouse skin carcinogen and was a more potent initiator of skin tumors in comparison to the wood or smokeless coal sample.

  3. Indoor air exposure to coal and wood combustion emissions associated with a high lung cancer rate in Xuan Wei, China

    SciTech Connect

    Mumford, J.L.; Chapman, R.S.; Harris, D.B. ); He, X.Z.; Cao, S.R.; Xian, Y.L.; Li, X.M. )

    1989-01-01

    Residents of Xuan Wei County in China have unusually high lung cancer mortality that cannot be attributed to tobacco use or occupational exposure. They are exposed to smoke from unvented, open pit coal or wood fires (often used for cooking and heating). The variation in lung cancer rates among communes within the county suggests that indoor combustion of smoky coal may be the prime determinant of lung cancer. To characterize the air in Xuan Wei homes, samples of air particles and semivolatile organic compounds were collected from homes located in two communes; one commune has a high rate of lung cancer, and the other has a low rate. Samples collected in the commune where the lung cancer rate is high and where smoky coal is the predominant fuel contained high concentrations of small particles with high organic content; organic extracts of these samples were mutagenic. Samples from homes in the wood-burning commune, which has a low rate of lung cancer, consisted mostly of larger particles of lower organic content and mutagenicity. The smoky coal sample was a mouse skin carcinogen and was a more potent initiator of skin tumors in comparison to the wood or smokeless coal sample.

  4. Quantification of emission reduction potentials of primary air pollutants from residential solid fuel combustion by adopting cleaner fuels in China.

    PubMed

    Shen, Guofeng

    2015-11-01

    Residential low efficient fuel burning is a major source of many air pollutants produced during incomplete combustions, and household air pollution has been identified as one of the top environmental risk factors. Here we compiled literature-reported emission factors of pollutants including carbon monoxide (CO), total suspended particles (TSPs), PM2.5, organic carbon (OC), elemental carbon (EC) and polycyclic aromatic hydrocarbons (PAHs) for different household energy sources, and quantified the potential for emission reduction by clean fuel adoption. The burning of crop straws, firewood and coal chunks in residential stoves had high emissions per unit fuel mass but lower thermal efficiencies, resulting in high levels of pollution emissions per unit of useful energy, whereas pelletized biofuels and coal briquettes had lower pollutant emissions and higher thermal efficiencies. Briquetting coal may lead to 82%-88% CO, 74%-99% TSP, 73%-76% PM2.5, 64%-98% OC, 92%-99% EC and 80%-83% PAH reductions compared to raw chunk coal. Biomass pelletizing technology would achieve 88%-97% CO, 73%-87% TSP, 79%-88% PM2.5, 94%-96% OC, 91%-99% EC and 63%-96% PAH reduction compared to biomass burning. The adoption of gas fuels (i.e., liquid petroleum gas, natural gas) would achieve significant pollutant reduction, nearly 96% for targeted pollutants. The reduction is related not only to fuel change, but also to the usage of high efficiency stoves. PMID:26574082

  5. Combustion rate limits of hydrogen plus hydrocarbon fuel: Air diffusion flames from an opposed jet burner technique

    NASA Technical Reports Server (NTRS)

    Pellett, Gerald L.; Guerra, Rosemary; Wilson, Lloyd G.; Reeves, Ronald N.; Northam, G. Burton

    1987-01-01

    Combustion of H2/hydrocarbon (HC) fuel mixtures may be considered in certain volume-limited supersonic airbreathing propulsion applications. Effects of HC addition to H2 were evaluated, using a recent argon-bathed, coaxial, tubular opposed jet burner (OJB) technique to measure the extinction limits of counterflow diffusion flames. The OJB flames were formed by a laminar jet of (N2 and/or HC)-diluted H2 mixture opposed by a similar jet of air at ambient conditions. The OJB data, derived from respective binary mixtures of H2 and methane, ethylene, or propane HCs, were used to characterize BLOWOFF and RESTORE. BLOWOFF is a sudden breaking of the dish-shaped OJB flame to a stable torus or ring shape, and RESTORE marks sudden restoration of the central flame by radial inward flame propagation. BLOWOFF is a measure of kinetically-limited flame reactivity/speed under highly stretched, but relatively ideal impingement flow conditions. RESTORE measures inward radial flame propagation rate, which is sensitive to ignition processes in the cool central core. It is concluded that relatively small molar amounts of added HC greatly reduce the reactivity characteristics of counterflow hydrogen-air diffusion flames, for ambient initial conditions.

  6. Combustion physics

    NASA Astrophysics Data System (ADS)

    Jones, A. R.

    1985-11-01

    Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

  7. The Impact of Residential Combustion Emissions on Air Quality and Human Health in China

    NASA Astrophysics Data System (ADS)

    Archer-Nicholls, S.; Wiedinmyer, C.; Baumgartner, J.; Brauer, M.; Cohen, A.; Carter, E.; Frostad, J.; Forouzanfar, M.; Xiao, Q.; Liu, Y.; Yang, X.; Hongjiang, N.; Kun, N.

    2015-12-01

    Solid fuel cookstoves are used heavily in rural China for both residential cooking and heating purposes. Their use contributes significantly to regional emissions of several key pollutants, including carbon monoxide, volatile organic compounds, oxides of nitrogen, and aerosol particles. The residential sector was responsible for approximately 36%, 46% and 81% of China's total primary PM2.5, BC and OC emissions respectively in 2005 (Lei et al., 2011). These emissions have serious consequences for household air pollution, ambient air quality, tropospheric ozone formation, and the resulting population health and climate impacts. This paper presents initial findings from the modeling component of a multi-disciplinary energy intervention study currently being conducted in Sichuan, China. The purpose of this effort is to quantify the impact of residential cooking and heating emissions on regional air quality and human health. Simulations with varying levels of residential emissions have been carried out for the whole of 2014 using the Weather Research and Forecasting model with Chemistry (WRF-Chem), a fully-coupled, "online" regional chemical transport model. Model output is evaluated against surface air quality measurements across China and compared with seasonal (winter and summer) ambient air pollution measurements conducted at the Sichuan study site in 2014. The model output is applied to available exposure—response relationships between PM2.5 and cardiopulmonary health outcomes. The sensitivity in different regions across China to the different cookstove emission scenarios and seasonality of impacts are presented. By estimating the mortality and disease burden risk attributable to residential emissions we demonstrate the potential benefits from large-scale energy interventions. Lei Y, Zhang Q, He KB, Streets DG. 2011. Primary anthropogenic aerosol emission trends for China, 1990-2005. Atmos. Chem. Phys. 11:931-954.

  8. Characteristics of CO laser based on combustion of carbon disulfide in air

    SciTech Connect

    Dudkin, V.A.; Eremenko, G.O.; Rukhin, V.B.

    1986-07-01

    Previously, it has been shown that a CO laser based on a carbon disulfide flame can emit radiation if air is used as the oxidant instead of oxygen. The results of further experiments with this type of laser are presented; they were made to examine the possibility of improving the performance by increasing the length of the active medium up to 300 cm and by optimizing the composition of the active medium and the pressure in the resonator. Since it has been frequently reported that the addition of N/sub 2/O increased the power of a carbon disulfide laser, a more detailed study of the effect on the laser radiation of adding N/sub 2/O to a CS/sub 2/-air mixture has been undertaken.

  9. Contribution of solid fuel, gas combustion or tobacco smoke to indoor air pollutant concentrations in Irish and Scottish homes

    PubMed Central

    Semple, S; Garden, C; Coggins, M; Galea, KS; Whelan, P; Cowie, H; Sánchez-Jimenéz, A; Thorne, PS; Hurley, JF; Ayres, JG

    2012-01-01

    There are limited data describing pollutant levels inside homes that burn solid fuel within developed country settings with most studies describing test conditions or the effect of interventions. This study recruited homes in Ireland and Scotland where open combustion processes take place. Open combustion was classified as coal, peat or wood fuel burning, use of a gas cooker or stove, or where there is at least one resident smoker. 24-hour data on airborne concentrations of particulate matter less than 2.5 microns in size (PM2.5), carbon monoxide (CO), endotoxin in inhalable dust and carbon dioxide (CO2), together with 2–3 week averaged concentrations of nitrogen dioxide (NO2) were collected in 100 houses during the winter and spring of 2009–2010. The geometric mean of the 24-hour time-weighted-average (TWA) PM2.5 concentration was highest in homes with resident smokers (99μg/m3 – much higher than the WHO 24-hour guidance value of 25 μg/m3. Lower geometric mean 24-hour TWA levels were found in homes that burned coal (7 μg/m3) or wood (6 μg/m3) and in homes with gas cookers (7 μg/m3). In peat-burning homes the average 24-hourPM2.5 level recorded was 11 μg/m3. Airborne endotoxin, CO, CO2 and NO2 concentrations were generally within indoor air quality guidance levels. PMID:22007695

  10. Monitoring intraurban spatial patterns of multiple combustion air pollutants in New York City: design and implementation.

    PubMed

    Matte, Thomas D; Ross, Zev; Kheirbek, Iyad; Eisl, Holger; Johnson, Sarah; Gorczynski, John E; Kass, Daniel; Markowitz, Steven; Pezeshki, Grant; Clougherty, Jane E

    2013-01-01

    Routine air monitoring provides data to assess urban scale temporal variation in pollution concentrations in relation to regulatory standards, but is not well suited to characterizing intraurban spatial variation in pollutant concentrations from local sources. To address these limitations and inform local control strategies, New York City developed a program to track spatial patterns of multiple air pollutants in each season of the year. Monitor locations include 150 distributed street-level sites chosen to represent a range of traffic, land-use and other characteristics. Integrated samples are collected at each distributed site for one 2-week session each season and in every 2-week period at five reference locations to track city-wide temporal variation. Pollutants sampled include PM(2.5) and constituents, nitrogen oxides, black carbon, ozone (summer only) and sulfur dioxide (winter only). During the first full year of monitoring more than 95% of designed samples were completed. Agreement between colocated samples was good (absolute mean % difference 3.2-8.9%). Street-level pollutant concentrations spanned a much greater range than did concentrations at regulatory monitors, especially for oxides of nitrogen and sulfur dioxide. Monitoring to characterize intraurban spatial gradients in ambient pollution usefully complements regulatory monitoring data to inform local air quality management. PMID:23321861

  11. Fuel-Air Mixing Effect on Nox Emissions for a Lean Premixed-Prevaporized Combustion System

    NASA Technical Reports Server (NTRS)

    Lee, Chi-Ming; Chun, Kue S.; Locke, Randy J.

    1995-01-01

    The lean premixed-prevaporized (LPP) concept effectively meets low nitrogen oxides (NOx) emission requirements for combustors with the high inlet temperature and pressure typical of the High-Speed Civil Transport (HSCT). For the LPP system fuel-air mixture uniformity is probably the most important factor for low NOx emissions. Previous studies have suggested that the fuel-air mixture uniformity can be severely affected by changing the number and configuration of fuel injection points. Therefore, an experimental study was performed to determine how the number of fuel injection points and their arrangement affect NOx emissions from an LPP system. The NOx emissions were measured by a gas-sampling probe in a flame-tube rig at the following conditions: inlet temperature of 810 K (1000 F), rig pressure of 10 atm, reference velocity of 150 ft/s, and residence time near 0.005 s. Additionally, a focused Schlieren diagnostic technique coupled with a high speed camera was used to provide a qualitative description of the spatial flow field.

  12. Combustion and NOx emission characteristics with respect to staged-air damper opening in a 600 MWe down-fired pulverized-coal furnace under deep-air-staging conditions.

    PubMed

    Kuang, Min; Li, Zhengqi; Wang, Zhihua; Jing, Xinjing; Liu, Chunlong; Zhu, Qunyi; Ling, Zhongqian

    2014-01-01

    Deep-air-staging combustion conditions, widely used in tangential-fired and wall-arranged furnaces to significantly reduce NOx emissions, are premature up to now in down-fired furnaces that are designed especially for industry firing low-volatile coals such as anthracite and lean coal. To uncover combustion and NOx emission characteristics under deep-air-staging conditions within a newly operated 600 MWe down-fired furnace and simultaneously understand the staged-air effect on the furnace performance, full-load industrial-size measurements taken of gas temperatures and species concentrations in the furnace, CO and NOx emissions in flue gas, and carbon in fly ash were performed at various staged-air damper openings of 10%, 20%, 30%, and 50%. Increasing the staged-air damper opening, gas temperatures along the flame travel (before the flame penetrating the staged-air zone) increased initially but then decreased, while those in the staged-air zone and the upper part of the hopper continuously decreased and increased, respectively. On opening the staged-air damper to further deepen the air-staging conditions, O2 content initially decreased but then increased in both two near-wall regions affected by secondary air and staged air, respectively, whereas CO content in both two regions initially increased but then decreased. In contrast to the conventional understanding about the effects of deep-air-staging conditions, here increasing the staged-air damper opening to deepen the air-staging conditions essentially decreased the exhaust gas temperature and carbon in fly ash and simultaneously increased both NOx emissions and boiler efficiency. In light of apparently low NOx emissions and high carbon in fly ash (i.e., 696-878 mg/m(3) at 6% O2 and 9.81-13.05%, respectively) developing in the down-fired furnace under the present deep-air-staging conditions, further adjustments such as enlarging the staged-air declination angle to prolong pulverized-coal residence times in the

  13. Intra-urban spatial variability in wintertime street-level concentrations of multiple combustion-related air pollutants: the New York City Community Air Survey (NYCCAS).

    PubMed

    Clougherty, Jane E; Kheirbek, Iyad; Eisl, Holger M; Ross, Zev; Pezeshki, Grant; Gorczynski, John E; Johnson, Sarah; Markowitz, Steven; Kass, Daniel; Matte, Thomas

    2013-01-01

    Although intra-urban air pollution differs by season, few monitoring networks provide adequate geographic density and year-round coverage to fully characterize seasonal patterns. Here, we report winter intra-urban monitoring and land-use regression (LUR) results from the New York City Community Air Survey (NYCCAS). Two-week integrated samples of fine particles (PM(2.5)), black carbon (BC), nitrogen oxides (NO(x)) and sulfur dioxide (SO(2)) were collected at 155 city-wide street-level locations during winter 2008-2009. Sites were selected using stratified random sampling, randomized across sampling sessions to minimize spatio-temporal confounding. LUR was used to identify GIS-based source indicators associated with higher concentrations. Prediction surfaces were produced using kriging with external drift. Each pollutant varied twofold or more across sites, with higher concentrations near midtown Manhattan. All pollutants were positively correlated, particularly PM(2.5) and BC (Spearman's r=0.84). Density of oil-burning boilers, total and truck traffic density, and temporality explained 84% of PM(2.5) variation. Densities of total traffic, truck traffic, oil-burning boilers and industrial space, with temporality, explained 65% of BC variation. Temporality, built space, bus route location, and traffic density described 67% of nitrogen dioxide variation. Residual oil-burning units, nighttime population and temporality explained 77% of SO(2) variation. Spatial variation in combustion-related pollutants in New York City was strongly associated with oil-burning and traffic density. Chronic exposure disparities and unique local sources can be identified through year-round saturation monitoring. PMID:23361442

  14. Proliferation of Rous sarcoma virus-infected, but not of normal, chicken fibroblasts in oxygen-enriched environment: preliminary report.

    PubMed

    Mitchell, R S; Elgas, R J; Balk, S D

    1976-04-01

    Both normal and Rous sarcoma virus-infected chicken fibroblasts proliferate in an incubator containing 95% air, 5% CO2. In an incubator atmosphere enriched with oxygen, however, the normal fibroblasts are maintained without proliferation, while the Rous sarcoma virus-infected fibroblasts continue to proliferate. This suggests that a respiratory function may be involved in the regulation of proliferation of normal cells, and that neoplastic cells may proliferate autonomously because of a deficiency in this regulatory function. PMID:177983

  15. Health effects of air pollution due to coal combustion in the Chestnut Ridge region of Pennsylvania

    SciTech Connect

    Batterman, S.; Golomb, D.

    1985-08-01

    This study used the seventeen monitor air quality network in the Chestnut Ridge region of Pennsylvania to evaluate the effect of pollutant trends and representations on measures of exposure. Data consisted of four and five years of SO/sub 2/ and TSP measurements, respectively, and were considered in deriving exposure models. A cross-sectional study of 4071 children aged 6 to 11 years of age was conducted in the spring of 1979. Standardized children's questionnaires were distributed to the parents and returned by the children to school, where spirometry was performed. The region was divided into low, moderate and high pollution areas on the basis of the 1974-1978, 3 h, 24 h, and annual averages for SO/sub 2/. After adjusting the respiratory symptom response outcomes and the pulmonary function levels for known predictors, no significant association was noted for level of SO/sub 2/. 65 refs., 16 figs., 19 tabs.

  16. Advection fog formation and aerosols produced by combustion-originated air pollution

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Liaw, G. S.; Vaughan, O. H., Jr.

    1980-01-01

    The way in which pollutants produced by the photochemical reaction of NO(X) and SO(X) affect the quality of the human environment through such phenomena as the formation of advection fog is considered. These pollutants provide the major source of condensation nuclei for the formation of fog in highways, airports and seaports. Results based on the monodisperse, multicomponent aerosol model show that: (1) condensation nuclei can grow and form a dense fog without the air having attained supersaturation; (2) the mass concentration range for NO(X) is one-third that of SO(X); and (3) the greater the mass concentration, the particle concentration, and the radius of condensation nuclei, the denser the fog that is formed.

  17. Biofilm spatial organization by the emerging pathogen Campylobacter jejuni: comparison between NCTC 11168 and 81-176 strains under microaerobic and oxygen-enriched conditions

    PubMed Central

    Turonova, Hana; Briandet, Romain; Rodrigues, Ramila; Hernould, Mathieu; Hayek, Nabil; Stintzi, Alain; Pazlarova, Jarmila; Tresse, Odile

    2015-01-01

    During the last years, Campylobacter has emerged as the leading cause of bacterial foodborne infections in developed countries. Described as an obligate microaerophile, Campylobacter has puzzled scientists by surviving a wide range of environmental oxidative stresses on foods farm to retail, and thereafter intestinal transit and oxidative damage from macrophages to cause human infection. In this study, confocal laser scanning microscopy (CLSM) was used to explore the biofilm development of two well-described Campylobacter jejuni strains (NCTC 11168 and 81-176) prior to or during cultivation under oxygen-enriched conditions. Quantitative and qualitative appraisal indicated that C. jejuni formed finger-like biofilm structures with an open ultrastructure for 81-176 and a multilayer-like structure for NCTC 11168 under microaerobic conditions (MAC). The presence of motile cells within the biofilm confirmed the maturation of the C. jejuni 81-176 biofilm. Acclimation of cells to oxygen-enriched conditions led to significant enhancement of biofilm formation during the early stages of the process. Exposure to these conditions during biofilm cultivation induced an even greater biofilm development for both strains, indicating that oxygen demand for biofilm formation is higher than for planktonic growth counterparts. Overexpression of cosR in the poorer biofilm-forming strain, NCTC 11168, enhanced biofilm development dramatically by promoting an open ultrastructure similar to that observed for 81-176. Consequently, the regulator CosR is likely to be a key protein in the maturation of C. jejuni biofilm, although it is not linked to oxygen stimulation. These unexpected data advocate challenging studies by reconsidering the paradigm of fastidious requirements for C. jejuni growth when various subpopulations (from quiescent to motile cells) coexist in biofilms. These findings constitute a clear example of a survival strategy used by this emerging human pathogen. PMID:26217332

  18. Understanding carbon isotope behaviour during combustion processes: a pre-requisite to using d13C in the field of air pollution.

    NASA Astrophysics Data System (ADS)

    Negrel, P.; Widory, D.

    2006-12-01

    Recent studies have demonstrated the effectiveness of stable isotopes in the field of air pollution research, especially their success in clearly discriminating the different sources of pollution in urban environments, and in tracing their respective impacts for a given sampling location. Among them, carbon isotopes have been used to track the origin of both gases (i.e. CO2; Widory &Javoy, 2003) and particulate matter (i.e. PM2 .5 and PM10; Widory et al., 2004). But understanding the carbon isotope behaviour that leads to this discrimination during combustion processes is a pre-requisite to using them as tracers of pollution sources in the atmosphere. d13C in fuels has been extensively used as an indicator of the processes leading to the generation of their parent crude-oil. Here, we isotopically characterise fuels and combustibles sold in Paris (France), and characterise the isotopic relations existing with their combustion by-products, i.e. gases (CO2) and particles (bulk carbon). Results show that d13C in fuels is clearly related to their physical state, with natural gas being strongly depleted in 13C while coal yields the highest d13C, and liquid fuels display intermediate values. This relation is also valid for exhaust gases, though d13C values of combustion particles form a homogeneous range within which no clear distinction is observed. Combustion processes are accompanied by carbon-isotope fractionation resulting from the combustion being incomplete. Carbon-isotope fractionation is strictly negative ( 1.3‰) during the formation of combustion gases, but generally positive in particle formation even if values close to zero are observed. This study helps understanding the processes leading to the d13C discrimination observed in pollution sources' exhausts, and definitely validates the use of carbon isotopes as tracers of atmospheric pollution.

  19. Heavy-duty diesel engine NO{sub x} reduction with nitrogen-enriched combustion air. Final CRADA report.

    SciTech Connect

    McConnell, S.; Energy Systems

    2010-07-28

    The concept of engine emissions control by modifying intake combustion gas composition from that of ambient air using gas separation membranes has been developed during several programs undertaken at Argonne. These have led to the current program which is targeted at heavy-duty diesel truck engines. The specific objective is reduction of NO{sub x} emissions by the target engine to meet anticipated 2007 standards while extracting a maximum of 5 percent power loss and allowing implementation within commercial constraints of size, weight, and cost. This report includes a brief review of related past programs, describes work completed to date during the current program, and presents interim conclusions. Following a work schedule adjustment in August 2002 to accommodate problems in module procurement and data analysis, activities are now on schedule and planned work is expected to be completed in September, 2004. Currently, we believe that the stated program requirements for the target engine can be met, based upon extrapolation of the work completed. Planned project work is designed to experimentally confirm these projections and result in a specification for a module package that will meet program objectives.

  20. Combustion of a Methane-Air Mixture in a Slot Burner with an Inert Insert in Mass Transfer to the Environment

    NASA Astrophysics Data System (ADS)

    Krainov, A. Yu.; Moiseeva, K. M.

    2016-03-01

    A problem on combustion of a methane-air mixture in a slot burner with an internal insert in mass transfer from the burner's exterior wall to the environment has been solved. A mathematical formulation of the problem takes account of the dependence of the diffusion, thermal-conductivity, and heat-transfer coefficients on temperature, and also of the heat removal from the gas to the environment by convective and radiant heat transfer. A numerical investigation has been carried out in a one-dimensional mathematical formulation of the problem in dimensional variables. The boundary of existence of a stable high-temperature regime of combustion of the methane-air mixture has been determined as a function of the rate of feed of the gas, the environmental temperature, and the width of the flow area of the burner.

  1. Thermochemical nonequilibrium and radiative interactions in supersonic hydrogen-air combustion

    NASA Technical Reports Server (NTRS)

    Chandrasekhar, R.; Tiwari, S. N.

    1992-01-01

    The two-dimensional, elliptic Navier-Stokes equations are used to investigate supersonic flows with nonequilibrium chemistry and thermodynamics, coupled with radiation, for hydrogen-air systems. The chemistry source term in the species equation is treated implicitly to alleviate the stiffness associated with fast reactions. The explicit, unsplit MacCormack finite-difference scheme is used to advance the governing equations in time, until convergence is achieved. The specific problem considered is the premixed, expanding flow in a supersonic nozzle. The reacting flow consists of seven species, one of which is the inert N2 molecule. The thermal state of the gas is modeled with one translational-rotational temperature and five vibrational temperatures. The harmonic oscillator model is used in the formulation for vibrational relaxation. The tangent slab approximation is used in the radiative flux formulation. A pseudo-gray model is used to represent the absorption-emission characteristics of the participating species. Results obtained for specific conditions indicate the presence of nonequilibrium in the expansion region. This reduces the radiative interactions and can have a significant influence on the flowfield.

  2. The effect of low-NO{sub x} combustion on residual carbon in fly ash and its adsorption capacity for air entrainment admixtures in concrete

    SciTech Connect

    Pedersen, K.H.; Jensen, A.D.; Dam-Johansen, K.

    2010-02-15

    Fly ash from pulverized coal combustion contains residual carbon that can adsorb the air-entraining admixtures (AEAs) added to control the air entrainment in concrete. This is a problem that has increased by the implementation of low-NO{sub x} combustion technologies. In this work, pulverized fuel has been combusted in an entrained flow reactor to test the impact of changes in operating conditions and fuel type on the AEA adsorption of ash and NO{sub x} formation. Increased oxidizing conditions, obtained by improved fuel-air mixing or higher excess air, decreased the AEA requirements of the produced ash by up to a factor of 25. This was due to a lower carbon content in the ash and a lower specific AEA adsorptivity of the carbon. The latter was suggested to be caused by changes in the adsorption properties of the unburned char and a decreased formation of soot, which was found to have a large AEA adsorption capacity based on measurements on a carbon black. The NO{sub x} formation increased by up to three times with more oxidizing conditions and thus, there was a trade-off between the AEA requirements of the ash and NO{sub x} formation. The type of fuel had high impact on the AEA adsorption behavior of the ash. Ashes produced from a Columbian and a Polish coal showed similar AEA requirements, but the specific AEA adsorptivity of the carbon in the Columbian coal ash was up to six times higher. The AEA requirements of a South African coal ash was unaffected by the applied operating conditions and showed up to 12 times higher AEA adsorption compared to the two other coal ashes. This may be caused by larger particles formed by agglomeration of the primary coal particles in the feeding phase or during the combustion process, which gave rise to increased formation of soot. (author)

  3. Research Opportunities for Cancer Associated with Indoor Air Pollution from Solid-Fuel Combustion

    PubMed Central

    Ghazarian, Armen A.; DeMarini, David M.; Sapkota, Amir; Jack, Darby; Lan, Qing; Winn, Deborah M.; Birnbaum, Linda S.

    2012-01-01

    Background: Indoor air pollution (IAP) derived largely from the use of solid fuels for cooking and heating affects about 3 billion people worldwide, resulting in substantial adverse health outcomes, including cancer. Women and children from developing countries are the most exposed populations. A workshop was held in Arlington, Virginia, 9–11 May 2011, to better understand women’s and children’s potential health effects from IAP in developing countries. Workshop participants included international scientists, manufacturers, policy and regulatory officials, community leaders, and advocates who held extensive discussions to help identify future research needs. Objectives: Our objective was to identify research opportunities regarding IAP and cancer, including research questions that could be incorporated into studies of interventions to reduce IAP exposure. In this commentary, we describe the state of the science in understanding IAP and its associations with cancer and suggest research opportunities for improving our understanding of the issues. Discussion: Opportunities for research on IAP and cancer include studies of the effect of IAP on cancers other than lung cancer; studies of genetic factors that modify susceptibility; studies to determine whether the effects of IAP are mediated via germline, somatic, and/or epigenetic changes; and studies of the effects of IAP exposure via dermal and/or oral routes. Conclusions: IAP from indoor coal use increases the risk of lung cancer. Installing chimneys can reduce risk, and some genotypes, including GSTM1-null, can increase risk. Additional research is needed regarding the effects of IAP on other cancers and the effects of different types of solid fuels, oral and dermal routes of IAP exposure, genetic and epigenetic mechanisms, and genetic susceptibility. PMID:22846419

  4. Effect of airstream velocity on mean drop diameters of water sprays produced by pressure and air atomizing nozzles. [for combustion studies

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1977-01-01

    A scanning radiometer was used to determine the effect of airstream velocity on the mean drop diameter of water sprays produced by pressure atomizing and air atomizing fuel nozzles used in previous combustion studies. Increasing airstream velocity from 23 to 53.4 meters per second reduced the Sauter mean diameter by approximately 50 percent with both types of fuel nozzles. The use of a sonic cup attached to the tip of an air assist nozzle reduced the Sauter mean diameter by approximately 40 percent. Test conditions included airstream velocities of 23 to 53.4 meters per second at 293 K and atmospheric pressure.

  5. Plasma igniter for internal-combustion engines

    NASA Technical Reports Server (NTRS)

    Breshears, R. R.; Fitzgerald, D. J.

    1978-01-01

    Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

  6. OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL

    SciTech Connect

    Lawrence E. Bool; Jack C. Chen; David R. Thompson

    2000-07-01

    Increased environmental regulations will require utility boilers to reduce NO{sub x} emissions to less than 0.15lb/MMBtu in the near term. Conventional technologies such as Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR) are unable to achieve these lowered emission levels without substantially higher costs and major operating problems. Oxygen enhanced combustion is a novel technology that allows utilities to meet the NO{sub x} emission requirements without the operational problems that occur with SCR and SNCR. Furthermore, oxygen enhanced combustion can achieve these NO{sub x} limits at costs lower than conventional technologies. The objective of this program is to demonstrate the use of oxygen enhanced combustion as a technical and economical method of meeting the EPA State Implementation Plan for NO{sub x} reduction to less than 0.15lb/MMBtu for a wide range of boilers and coal. The oxygen enhanced coal combustion program (Task 1) focused this quarter on the specific objective of exploration of the impact of oxygen enrichment on NO{sub x} formation utilizing small-scale combustors for parametric testing. Research efforts toward understanding any limitations to the applicability of the technology to different burners and fuels such as different types of coal are underway. The objective of the oxygen transport membrane (OTM) materials development program (Task 2.1) is to ascertain a suitable material composition that can be fabricated into dense tubes capable of producing the target oxygen flux under the operating conditions. This requires that the material have sufficient oxygen permeation resulting from high oxygen ion conductivity, high electronic conductivity and high oxygen surface exchange rate. The OTM element development program (Task 2.2) objective is to develop, fabricate and characterize OTM elements for laboratory and pilot reactors utilizing quality control parameters to ensure reproducibility and superior performance

  7. MUNICIPAL WASTEWATER SLUDGE COMBUSTION TECHNOLOGY

    EPA Science Inventory

    The publication describes and evaluates the various municipal sludge combustion systems. It also emphasizes the necessity for considering and evaluating the costs involved in the total sludge management train, including dewatering, combustion, air pollution control, and ash dispo...

  8. The Influence of Fuel Moisture, Charge Size, Burning Rate and Air Ventilation Conditions on Emissions of PM, OC, EC, Parent PAHs, and Their Derivatives from Residential Wood Combustion

    PubMed Central

    Shen, Guofeng; Xue, Miao; Wei, Siye; Chen, Yuanchen; Wang, Bin; Wang, Rong; Lv, Yan; Shen, Huizhong; Li, Wei; Zhang, Yanyan; Huang, Ye; Chen, Han; Wei, Wen; Zhao, Qiuyue; Li, Bin; Wu, Haisuo; TAO, Shu

    2014-01-01

    Controlled combustion experiments were conducted to investigate the influence of fuel charge size, moisture, air ventilation and burning rate on the emission factors (EFs) of carbonaceous particulate matter, parent polycyclic aromatic hydrocarbons (pPAHs) and their derivatives from residential wood combustion in a typical brick cooking stove. Measured EFs were found to be independent of fuel charge size, but increased with increasing fuel moisture. Pollution emissions from a normal burning under an adequate air supply condition were the lowest for most pollutants, while more pollutants were emitted when the oxygen deficient atmosphere was formed in stove chamber during fast burning. The impact of these 4 factors on particulate matter size distribution was also studied. Modified combustion efficiency and the four investigated factors explained 68, 72, and 64% of total variations in EFs of PM, organic carbon, and oxygenated PAHs, respectively, but only 36, 38 and 42% of the total variations in EFs of elemental carbon, pPAHs and nitro-PAHs, respectively. PMID:24520723

  9. Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment.

    PubMed

    Topaz, Moris

    2012-05-01

    Regulated negative pressure-assisted wound therapy (RNPT) should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound's environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially influence wound-host interactions, and when properly applied may enhance wound healing. RNPT is a simple, safe, and affordable tool that can be utilized in a wide range of acute and chronic conditions, with reduced need for complicated surgical procedures, and antibiotic treatment. This technology has been shown to be effective and safe, saving limbs and lives on a global scale. Regulated, oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) is an innovative technology, whereby supplemental oxygen is concurrently administered with RNPT for their synergistic effect on treatment and prophylaxis of anaerobic wound infection and promotion of wound healing. Understanding the basic science, modes of operation and the associated risks of these technologies through their fundamental clinical mechanisms is the main objective of this review. PMID:23162229

  10. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  11. Influence of the overfire air ratio on the NO(x) emission and combustion characteristics of a down-fired 300-MW(e) utility boiler.

    PubMed

    Ren, Feng; Li, Zhengqi; Chen, Zhichao; Fan, Subo; Liu, Guangkui

    2010-08-15

    Down-fired boilers used to burn low-volatile coals have high NO(x) emissions. To find a way of solving this problem, an overfire air (OFA) system was introduced on a 300 MW(e) down-fired boiler. Full-scale experiments were performed on this retrofitted boiler to explore the influence of the OFA ratio (the mass flux ratio of OFA to the total combustion air) on the combustion and NO(x) emission characteristics in the furnace. Measurements were taken of gas temperature distributions along the primary air and coal mixture flows, average gas temperatures along the furnace height, concentrations of gases such as O(2), CO, and NO(x) in the near-wall region and carbon content in the fly ash. Data were compared for five different OFA ratios. The results show that as the OFA ratio increases from 12% to 35%, the NO(x) emission decreases from 1308 to 966 mg/Nm(3) (at 6% O(2) dry) and the carbon content in the fly ash increases from 6.53% to 15.86%. Considering both the environmental and economic effect, 25% was chosen as the optimized OFA ratio. PMID:20666359

  12. Reduction of noxious substance emissions at the pulverized fuel combustion in the combustor of the BKZ-160 boiler of the Almaty heat electropower station using the "Overfire Air" technology

    NASA Astrophysics Data System (ADS)

    Askarova, A. S.; Messerle, V. E.; Ustimenko, A. B.; Bolegenova, S. A.; Bolegenova, S. A.; Maximov, V. Yu.; Yergalieva, A. B.

    2016-01-01

    The computational experiments using the "Overfire Air" (OFA) technology at the coal dust torch combustion in the combustor of the BKZ-160 boiler of the heat power plant No. 2 in Almaty have been conducted. The results show a possibility of reaching a reduction of the emission of noxious nitrogen oxides NO x and minimizing the energy losses. The results of numerical experiments on the influence of the additional air supply on the main characteristics of heat and mass transfer are presented. A comparison with the base regime of the solid fuel combustion when there is no supply of the additional air (OFA = 0 %) has been made.

  13. A practical approach to estimate emission rates of indoor air pollutants due to the use of personal combustible products based on small-chamber studies.

    PubMed

    Szulejko, Jan E; Kim, Ki-Hyun

    2016-02-01

    As emission rates of airborne pollutants are commonly measured from combusting substances placed inside small chambers, those values need to be re-evaluated for the possible significance under practical conditions. Here, a simple numerical procedure is investigated to extrapolate the chamber-based emission rates of formaldehyde that can be released from various combustible sources including e-cigarettes, conventional cigarettes, or scented candles to their concentration levels in a small room with relatively poor ventilation. This simple procedure relies on a mass balance approach by considering the masses of pollutants emitted from source and lost through ventilation under the assumption that mixing occurs instantaneously in the room without chemical reactions or surface sorption. The results of our study provide valuable insights into re-evaluation procedure of chamber data to allow comparison between extrapolated and recommended values to judge the safe use of various combustible products in confined spaces. If two scented candles with a formaldehyde emission rate of 310 µg h(-1) each were lit for 4 h in a small 20 m(3) room with an air change rate of 0.5 h(-1), then the 4-h (candle lit) and 8-h (up to 8 h after candle lighting) TWA [FA] were determined to be 28.5 and 23.5 ppb, respectively. This is clearly above the 8-h NIOSH recommended exposure limit (REL) time weighted average of 16 ppb. PMID:26495830

  14. Experimental and numerical study of the accuracy of flame-speed measurements for methane/air combustion in a slot burner

    SciTech Connect

    Selle, L.; Ferret, B.; Poinsot, T.

    2011-01-15

    Measuring the velocities of premixed laminar flames with precision remains a controversial issue in the combustion community. This paper studies the accuracy of such measurements in two-dimensional slot burners and shows that while methane/air flame speeds can be measured with reasonable accuracy, the method may lack precision for other mixtures such as hydrogen/air. Curvature at the flame tip, strain on the flame sides and local quenching at the flame base can modify local flame speeds and require corrections which are studied using two-dimensional DNS. Numerical simulations also provide stretch, displacement and consumption flame speeds along the flame front. For methane/air flames, DNS show that the local stretch remains small so that the local consumption speed is very close to the unstretched premixed flame speed. The only correction needed to correctly predict flame speeds in this case is due to the finite aspect ratio of the slot used to inject the premixed gases which induces a flow acceleration in the measurement region (this correction can be evaluated from velocity measurement in the slot section or from an analytical solution). The method is applied to methane/air flames with and without water addition and results are compared to experimental data found in the literature. The paper then discusses the limitations of the slot-burner method to measure flame speeds for other mixtures and shows that it is not well adapted to mixtures with a Lewis number far from unity, such as hydrogen/air flames. (author)

  15. Diesel engine combustion processes

    SciTech Connect

    1995-12-31

    Diesel Engine Combustion Processes guides the engineer and research technician toward engine designs which will give the ``best payoff`` in terms of emissions and fuel economy. Contents include: Three-dimensional modeling of soot and NO in a direct-injection diesel engine; Prechamber for lean burn for low NOx; Modeling and identification of a diesel combustion process with the downhill gradient search method; The droplet group micro-explosions in W/O diesel fuel emulsion sprays; Combustion process of diesel spray in high temperature air; Combustion process of diesel engines at regions with different altitude; and more.

  16. Combuster. [low nitrogen oxide formation

    NASA Technical Reports Server (NTRS)

    Mckay, R. A. (Inventor)

    1978-01-01

    A combuster is provided for utilizing a combustible mixture containing fuel and air, to heat a load fluid such as water or air, in a manner that minimizes the formation of nitrogen oxide. The combustible mixture passes through a small diameter tube where the mixture is heated to its combustion temperature, while the load fluid flows past the outside of the tube to receive heat. The tube is of a diameter small enough that the combustible mixture cannot form a flame, and yet is not subject to wall quench, so that combustion occurs, but at a temperature less than under free flame conditions. Most of the heat required for heating the combustible mixture to its combustion temperature, is obtained from heat flow through the walls of the pipe to the mixture.

  17. Combustion of Micropowdered Biomass

    NASA Astrophysics Data System (ADS)

    Geil, Ethan; Thorne, Robert

    2009-03-01

    Combustion of finely powdered biomass has the potential to replace heating oil, which accounts for a significant fraction of US oil consumption, in heating, cooling and local power generation applications. When ground to 30-150 micron powders and dispersed in air, wood and other biomass can undergo deflagrating combustion, as occurs with gaseous and dispersed liquid fuels. Combustion is very nearly complete, and in contrast to sugar/starch or cellulose-derived ethanol, nearly all of the available plant mass is converted to usable energy so the economics are much more promising. We are exploring the fundamental combustion science of biomass powders in this size range. In particular, we are examining how powder size, powder composition (including the fraction of volatile organics) and other parameters affect the combustion regime and the combustion products.

  18. Opportunities in pulse combustion

    NASA Astrophysics Data System (ADS)

    Brenchley, D. L.; Bomelburg, H. J.

    1985-10-01

    In most pulse combustors, the combustion occurs near the closed end of a tube where inlet valves operate in phase with the pressure amplitude variations. Thus, within the combustion zone, both the temperature and the pressure oscillate around a mean value. However, the development of practical applications of pulse combustion has been hampered because effective design requires the right combination of the combustor's dimensions, valve characteristics, fuel/oxidizer combination, and flow pattern. Pulse combustion has several additional advantages for energy conversion efficiency, including high combustion and thermal efficiency, high combustion intensity, and high convective heat transfer rates. Also, pulse combustion can be self-aspirating, generating a pressure boost without using a blower. This allows the use of a compact heat exchanger that may include a condensing section and may obviate the need for a chimney. In the last decade, these features have revived interest in pulse combustion research and development, which has resulted in the development of a pulse combustion air heater by Lennox, and a pulse combustion hydronic unit by Hydrotherm, Inc. To appraise this potential for energy savings, a systematic study was conducted of the many past and present attempts to use pulse combustion for practical purposes. The authors recommended areas where pulse combustion technology could possibly be applied in the future and identified areas in which additional R and D would be necessary. Many of the results of the study project derived from a special workshop on pulse combustion. This document highlights the main points of the study report, with particular emphasis on pulse combustion application in chemical engineering.

  19. Combustion furnace and burner

    SciTech Connect

    McElroy, J. G.

    1985-12-03

    The combustion system includes a hearth lined with refractory, a combustion chamber formed in the refractory, an air manifold mounted on the hearth, a plurality of gas manifold extending through the air manifold and into the combustion chamber, and a diffuser mounted on the manifolds to cause turbulence in the air/gas mixture. The gas manifolds include aspirating means for combining the air and gas. The combustion chamber is elongated and has an elongated neck with a flue gas exit slot over which the work piece passes. The flue gas from the combustion of the air/gas mixture in the combustion chamber increases in velocity as the flue gas passes through the elongated neck and exits the flue gas exit slot. The slot has a length sufficient to permit the work piece to rotate 360/sup 0/ as the work piece rotates and travels through the hearth. This causes the work piece to be uniformly heated over every square inch of its surface.

  20. A Novel High-Heat Transfer Low-NO{sub x} Natural Gas Combustion System. Final Technical Report

    SciTech Connect

    Abbasi, H.

    2004-01-01

    A novel high-heat transfer low NO(sub x) natural gas combustion system. The objectives of this program are to research, develop, test, and commercialize a novel high-heat transfer low-NO{sub x} natural gas combustion system for oxygen-, oxygen-enriched air, and air-fired furnaces. This technology will improve the process efficiency (productivity and product quality) and the energy efficiency of high-temperature industrial furnaces by at least 20%. GTI's high-heat transfer burner has applications in high-temperature air, oxygen-enriched air, and oxygen furnaces used in the glass, metals, cement, and other industries. Development work in this program is focused on using this burner to improve the energy efficiency and productivity of glass melting furnaces that are major industrial energy consumers. The following specific project objectives are defined to provide a means of achieving the overall project objectives. (1) Identify topics to be covered, problems requiring attention, equipment to be used in the program, and test plans to be followed in Phase II and Phase III. (2) Use existing codes to develop models of gas combustion and soot nucleation and growth as well as a thermodynamic and parametric description of furnace heat transfer issues. (3) Conduct a parametric study to confirm the increase in process and energy efficiency. (4) Design and fabricate a high-heat transfer low-NOx natural gas burners for laboratory, pilot- and demonstration-scale tests. (5) Test the high-heat transfer burner in one of GTI's laboratory-scale high-temperature furnaces. (6) Design and demonstrate the high-heat transfer burner on GTI's unique pilot-scale glass tank simulator. (7) Complete one long term demonstration test of this burner technology on an Owens Corning full-scale industrial glass melting furnace. (8) Prepare an Industrial Adoption Plan. This Plan will be updated in each program Phase as additional information becomes available. The Plan will include technical and

  1. Effect of heat recirculation on the self-sustained catalytic combustion of propane/air mixtures in a quartz reactor

    SciTech Connect

    Scarpa, A.; Pirone, R.; Russo, G.; Vlachos, D.G.

    2009-05-15

    The self-sustained catalytic combustion of propane is experimentally studied in a two-pass, quartz heat-recirculation reactor (HRR) and compared to that in a no (heat) recirculation reactor (NRR). Structured monolithic reactors with Pt/{gamma}-Al{sub 2}O{sub 3}, LaMnO{sub 3}/{gamma}-Al{sub 2}O{sub 3}, and Pt doped perovskite catalysts have been compared in the HRR and NRR configurations. Heat recirculation enhances combustion stability, by widening the operating window of self-sustained operation, and changes the mode of stability loss from blowout to extinction. It is found that thermal shields (upstream and downstream of the monolith) play no role in the stability of a HRR but increase the stability of a NRR. The stability of a HRR follows this trend: Pt/{gamma}-Al{sub 2}O{sub 3} > doped perovskite > LaMnO{sub 3}/{gamma}-Al{sub 2}O{sub 3}. Finally, a higher cell density monolith enlarges the operating window of self-sustained combustion, and allows further increase of the power density of the process. (author)

  2. Safety Design and Mock-Up Tests on the Combustion of Hydrogen-Air Mixture in the Vertical CNS Channel of the CARR-CNS

    SciTech Connect

    Qingfeng Yu; Quanke Feng

    2006-07-01

    A two-phase thermo-siphon loop is applied to the Cold Neutron Source (CNS) of China Advanced Research Reactor (CARR). The moderator is liquid hydrogen. The two-phase thermo-siphon consists of the crescent-shape moderator cell, the moderator transfer tube, and the condenser. The hydrogen is supplied from the buffer tank to the condenser. The most characteristic point is that the cold helium gas is introduced into the helium sub-cooling system covering the moderator cell and then flows up through the tube covering the moderator transfer tube into the condenser. The helium sub-cooling system also reduces the void fraction of the liquid hydrogen and takes a role of the helium barrier for preventing air from intruding into the hydrogen system. We call the two-phase thermo-siphon the hydrogen cold system. The main part of this system is installed in the CNS channel made of 6061 aluminum alloy (6061A) of 6 mm in thickness, 270 mm in outer diameter and about 6 m in height. For confirming the safety of the CNS, the combustion tests were carried out using the hydrogen-air mixture under the conditions in which air is introduced into the tube at 1 atmosphere, and then hydrogen gas is supplied from the gas cylinder up to the test pressures. And maximum test pressure is 0.140 MPa Gauge (G). This condition includes the design accident of the CNS. The peak pressure due to combustion is 1.09 MPa, and the design strength of the CNS channel is 3 MPa. The safety of the CNS was thus verified even if the design basis accident occurs. The pressure distribution, the stress, and the displacement of the tube were also measured. (authors)

  3. EFFECTS OF CHANGING COALS ON THE EMISSIONS OF METAL HAZARDOUS AIR POLLUTANTS FROM THE COMBUSTION OF PULVERIZED COAL

    EPA Science Inventory

    The report discusses tests conducted at EPA's Air Pollution Prevention and Control Division to evaluate the effects of changing coals on emissions of metal hazardous air pollutants from coal-fired boilers. Six coals were burned in a 29 kW (100,000 Btu/hr) down-fired combustor und...

  4. NO.sub.x reduction method

    DOEpatents

    Sekar, Ramanujam R.; Hoppie, Lyle O.

    1996-01-01

    A method of reducing oxides of nitrogen (NO.sub.X) in the exhaust of an internal combustion engine includes producing oxygen enriched air and nitrogen enriched air by an oxygen enrichment device. The oxygen enriched air may be provided to the intake of the internal combustion engine for mixing with fuel. In order to reduce the amount of NO.sub.X in the exhaust of the internal combustion engine, the molecular nitrogen in the nitrogen enriched air produced by the oxygen enrichment device is subjected to a corona or arc discharge so as to create a plasma and as a result, atomic nitrogen. The resulting atomic nitrogen then is injected into the exhaust of the internal combustion engine causing the oxides of nitrogen in the exhaust to be reduced into nitrogen and oxygen. In one embodiment of the present invention, the oxygen enrichment device that produces both the oxygen and nitrogen enriched air can include a selectively permeable membrane.

  5. Combustion Processes in the Aerospace Environment

    NASA Technical Reports Server (NTRS)

    Huggett, Clayton

    1969-01-01

    The aerospace environment introduces new and enhanced fire hazards because the special atmosphere employed may increase the frequency and intensity of fires, because the confinement associated with aerospace systems adversely affects the dynamics of fire development and control, and because the hostile external environments limit fire control and rescue operations. Oxygen enriched atmospheres contribute to the fire hazard in aerospace systems by extending the list of combustible fuels, increasing the probability of ignition, and increasing the rates of fire spread and energy release. A system for classifying atmospheres according to the degree of fire hazard, based on the heat capacity of the atmosphere per mole of oxygen, is suggested. A brief exploration of the dynamics of chamber fires shows that such fires will exhibit an exponential growth rate and may grow to dangerous size in a very short time. Relatively small quantities of fuel and oxygen can produce a catastrophic fire in a closed chamber.

  6. Detonation cell size measurements in high-temperature hydrogen-air-steam mixtures at the BNL high-temperature combustion facility

    SciTech Connect

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.L.

    1997-11-01

    The High-Temperature Combustion Facility (HTCF) was designed and constructed with the objective of studying detonation phenomena in mixtures of hydrogen-air-steam at initially high temperatures. The central element of the HTCF is a 27-cm inner-diameter, 21.3-m long cylindrical test vessel capable of being heating to 700K {+-} 14K. A unique feature of the HTCF is the {open_quotes}diaphragmless{close_quotes} acetylene-oxygen gas driver which is used to initiate the detonation in the test gas. Cell size measurements have shown that for any hydrogen-air-steam mixture, increasing the initial mixture temperature, in the range of 300K to 650K, while maintaining the initial pressure of 0.1 MPa, decreases the cell size and thus makes the mixture more detonable. The effect of steam dilution on cell size was tested in stoichiometric and off-stoichiometric (e.g., equivalence ratio of 0.5) hydrogen-air mixtures. Increasing the steam dilution in hydrogen-air mixtures at 0.1 MPa initial pressure increases the cell size, irrespective of initial temperature. It is also observed that the desensitizing effect of steam diminished with increased initial temperature. A 1-dimensional, steady-state Zel`dovich, von Neumann, Doring (ZND) model, with full chemical kinetics, has been used to predict cell size for hydrogen-air-steam mixtures at different initial conditions. Qualitatively the model predicts the overall trends observed in the measured cell size versus mixture composition and initial temperature and pressure. It was found that the proportionality constant used to predict detonation cell size from the calculated ZND model reaction zone varies between 10 and 100 depending on the mixture composition and initial temperature. 32 refs., 35 figs.

  7. Method and apparatus for determining the proportions of the constituents of the air-fuel mixture supplied to an internal combustion engine

    SciTech Connect

    Peter, C.

    1980-11-04

    A method and apparatus are described for determining the proportions of the air-fuel mixture constituents supplied to an internal combustion engine from a mixture preparing device such as a carburator, a fuel injection device or other suitable mixture preparing device. The method according to the invention serves to simplify the processing of output signals that are supplied to a mixture preparing device having at least two lambda sensors. The invention is especially suitable for use with large engines with several exhaust conduit systems, such as so-called v-engines, in which generally there is an unequal mixture distribution between the two rows of cylinders. By employing at least two lambda sensors in the exhaust gas conduit system for monitoring the exhaust gas composition, one succeeds in determining the mixture composition of the air-fuel mixture applied to all cylinders, and in influencing the air-fuel mixture in a suitable supplementary manner by a feed back of the actual value signals generated by the lambda sensors to the fuel preparation device, so that a desirable overall exhaust gas average value can be achieved. The apparatus employs two integrators and suitable logic circuitry for applying the lambda sensor signals to the integrators in such a manner that one integrator regulates the entire mixture in the desired direction, according to the sensor signals supplied to it, while the other integrator sets the amplitude of the oscillation fluctuations at a value that corresponds to the lambda differential.

  8. Regulating low-NOx and high-burnout deep-air-staging combustion under real-furnace conditions in a 600 MWe down-fired supercritical boiler by strengthening the staged-air effect.

    PubMed

    Kuang, Min; Wang, Zhihua; Zhu, Yanqun; Ling, Zhongqian; Li, Zhengqi

    2014-10-21

    A 600 MW(e) down-fired pulverized-coal supercritical boiler, which was equipped with a deep-air-staging combustion system for reducing the particularly high NOx emissions, suffered from the well-accepted contradiction between low NOx emissions and high carbon in fly ash, in addition to excessively high gas temperatures in the hopper that jeopardized the boiler's safe operations. Previous results uncovered that under low-NOx conditions, strengthening the staged-air effect by decreasing the staged-air angle and simultaneously increasing the staged-air damper opening alleviated the aforementioned problems to some extent. To establish low-NOx and high-burnout circumstances and control the aforementioned hopper temperatures, a further staged-air retrofit with horizontally redirecting staged air through an enlarged staged-air slot area was performed to greatly strengthen the staged-air effect. Full-load industrial-size measurements were performed to confirm the availability of this retrofit. The present data were compared with those published results before the retrofit. High NOx emissions, low carbon in fly ah, and high hopper temperatures (i.e., levels of 1036 mg/m(3) at 6% O2, 3.72%, and about 1300 °C, respectively) appeared under the original conditions with the staged-air angle of 45° and without overfire air (OFA) application. Applying OFA and reducing the angle to 20° achieved an apparent NOx reduction and a moderate hopper temperature decrease while a sharp increase in carbon in fly ash (i.e., levels of 878 mg/m(3) at 6% O2, about 1200 °C, and 9.81%, respectively). Fortunately, the present staged-air retrofit was confirmed to be applicable in regulating low-NOx, high-burnout, and low hopper temperature circumstances (i.e., levels of 867 mg/m(3) at 6% O2, 5.40%, and about 1100 °C, respectively). PMID:25256210

  9. A Simulation of the Effects of Varying Repetition Rate and Pulse Width of Nanosecond Discharges on Premixed Lean Methane-Air Combustion

    DOE PAGESBeta

    Bak, Moon Soo; Cappelli, Mark A.

    2012-01-01

    Two-dimensional kinetic simulation has been carried out to investigate the effects of repetition rate and pulse width of nanosecond repetitively pulsed discharges on stabilizing premixed lean methane-air combustion. The repetition rate and pulse width are varied from 10 kHz to 50 kHz and from 9 ns to 2 ns while the total power is kept constant. The lower repetition rates provide larger amounts of radicals such as O, H, and OH. However, the effect on stabilization is found to be the same for all of the tested repetition rates. The shorter pulse width is found to favor the production of species in higher electronicmore » states, but the varying effects on stabilization are also found to be small. Our results indicate that the total deposited power is the critical element that determines the extent of stabilization over this range of discharge properties studied.« less

  10. INHALABLE PARTICLES AND PULMONARY HOST DEFENSE: 'IN VIVO' AND 'IN VITRO' EFFECTS OF AMBIENT AIR AND COMBUSTION PARTICLES

    EPA Science Inventory

    The ability of particulate air pollutants (and possible constituents) to alter pulmonary host defenses was examined using an in vitro alveolar macrophage cytotoxicity assay and an in vivo bacterial infectivity screening test which employed intratracheal injection of the particles...

  11. Mock-up tests on the combustion of hydrogen air mixture in the vertical tube simulating the CNS channel of the CARR

    NASA Astrophysics Data System (ADS)

    Yu, Qingfeng; Feng, Quanke; Kawai, Takeshi; Xu, Jian

    2007-01-01

    A two-phase thermo-siphon loop for removing nuclear heating and maintaining the stable liquid level in the moderator cell was adopted for the cold neutron source (CNS) of the China advanced research reactor (CARR). The moderator is liquid hydrogen. The two-phase thermo-siphon loop consists of the crescent-shape moderator cell, the moderator transfer tube, and the condenser. The hydrogen is supplied from the buffer tank to the condenser. The main feature of the loop is that the moderator cell is covered by the helium sub-cooling system. The cold helium gas from the helium refrigerator is firstly introduced into the helium sub-cooling system and then flows up through the tube covering the moderator transfer tube into the condenser. The main part of this system is installed in the CNS vertical channel made of aluminum alloy 6061 T6 (Al-6061-T6) of 6 mm in thickness, 270 mm in outer diameter and about 6 m in height. For confirming the safety of the CNS channel, the combustion tests using a tube compatible with the CNS channel were carried out using the hydrogen-air mixture under which air is introduced into the tube at 1 atmosphere, and then hydrogen gas is supplied from the gas cylinder up to the test pressures. And maximum test pressure is 0.14 MPa G. This condition is involved with the maximum design basis accident of the CARR-CNS. The peak pressure due to combustion was 1.09 MPa, and the design pressure of the CNS channel is 3 MPa. The safety of the CNS was thus verified even if the maximum design basis accident occurs. The pressure and stress distributions along the axial direction and the displacement of the tube were also measured.

  12. Leaching behavior and possible resource recovery from air pollution control residues of fluidized bed combustion of municipal solid waste

    SciTech Connect

    Abbas, Z.; Andersson, B.A.; Steenari, B.M.

    1999-07-01

    Ash residues are generated at several points during combustion of municipal solid waste (MSW), i.e., in cyclones, electrostatic precipitators and fabric filters. Such residues are of a complex physical and chemical nature and are often enriched in soluble salts and heavy metals such as Pb, Cd and Zn. Fluidized bed combustion (FBC) of MSW is a relatively new technique and very little information is available about the leaching behavior of its residues. In this study, the total elemental composition, mineralogy and leaching behavior of cyclone and bag-house filter ashes from a bubbling fluidized bed (BFB) boiler fired with municipal solid waste have been investigated. In addition, the possibilities of recovery heavy metals from these ashes were studied. The long-term leaching behavior of the ash constituents was evaluated using a two-step batch leaching test known as the CEN-test, whereas short and medium term leaching behavior was evaluated using a Column test. The extraction of elements from cyclone and filter ashes with various acidic solutions was also investigated. The leaching behavior of acid washed ashes was evaluated using the CEN test. The cyclone ash was mainly composed of aluminosilicate minerals, whereas the filter ash consisted of chlorides and hydroxides of alkali and alkaline earth metals. The concentration of heavy metals such as Zn, Cu, Cd and Pb was higher in the filter ash than in the cyclone ash. The leached amounts of sulfates and Pb from the cyclone ash decreased with leaching test contact time, indicating the formation of secondary mineral phases. Large amounts of chlorides, sulfates, Ca, Cu and Pb were leached from the filter ash. Acid extraction removed large amounts ({gt}50%) of Zn, Pb and Cu from the filter ash and approximately 56% of the total amount of Zn present in the cyclone ash. An efficient removal of heavy metal species from these types of ashes can probably be achieved by application of a recycling or multi-step process.

  13. Combustion products generating and metering device

    NASA Technical Reports Server (NTRS)

    Wiberg, R. E.; Klisch, J. A. (Inventor)

    1971-01-01

    An apparatus for generating combustion products at a predetermined fixed rate, mixing the combustion products with air to achieve a given concentration, and distributing the resultant mixture to an area or device to be tested is described. The apparatus is comprised of blowers, a holder for the combustion product generating materials (which burn at a predictable and controlled rate), a mixing plenum chamber, and a means for distributing the air combustion product mixture.

  14. Decomposition of nitric oxide in a hot nitrogen stream to synthesize air for hypersonic wind tunnel combustion testing

    NASA Technical Reports Server (NTRS)

    Zumdieck, J. F.; Zlatarich, S. A.

    1974-01-01

    A clean source of high enthalpy air was obtained from the exothermic decomposition of nitric oxide in the presence of strongly heated nitrogen. A nitric oxide jet was introduced into a confined coaxial nitrogen stream. Measurements were made of the extent of mixing and reaction. Experimental results are compared with one- and two-dimensional chemical kinetics computations. Both analyses predict much lower reactivity than was observed experimentally. Inlet nitrogen temperatures above 2400 K were sufficient to produce experimentally a completely reacted gas stream of synthetic air.

  15. Reduction of gas phase air toxics from combustion and incineration sources using the GE-Mitsui-BG activated coke process

    SciTech Connect

    Olson, D.G.; Tsuji, K.; Shiraishi, I.

    1998-04-01

    The dry desulfurization, denitification and air toxics removal process using activated coke (AC) was originally researched and developed during the 1960`s by Bergbau Forschung (BF), now called Deutsche Montan Technologies. Mitsui Mining Company (MMC) signed a licensing agreement with BF in 1982 to investigate, test and adapt the system to facilities in Japan. Japanese regulations are stricter than in the United States toward SOx/NOx pollutants, as well as flyash emissions from the utility industry, oil refineries and other industries. This process is installed on four coal-fired boilers and Fluidized Catalytic Cracker (FCC) units. These plants were constructed by MMC in Japan and Uhde GmbH in Germany. General Electric Environmental Services, Inc. (GEESI) signed a license agreement in 1992 with MMC and Mitsui and Company, Ltd. of Tokyo. Under this agreement, GEESI will market, design, fabricate and install the Mitsui-BF process for flue gas cleaning applications in North America. MMC also developed a technology to produce AC used in the dry DeSOx/DeNOx/Air Toxics removal process based on their own metallurgical coke manufacturing technology. This paper provides information on the details of MMC`s AC used in the dry DeSOx/DeNOx/Air Toxics removal process and of the DeSOx/DeNOx/Air Toxics removal process itself.

  16. Rotational level-dependent collisional broadening and line shift of the A2Sigma(+)-X2Pi (1,0) band of OH in hydrogen-air combustion gases

    NASA Technical Reports Server (NTRS)

    Kessler, W. J.; Allen, M. G.; Davis, S. J.

    1993-01-01

    Measurements of the collisional broadening and line shift of the (1,0) band of the A2Sigma(+)-X2Pi system of OH are reported in atmospheric pressure hydrogen-air combustion gases. The measurements were made using a single-mode, narrow linewidth, frequency-doubled ring dye laser operating near 283 nm. The OH was generated in the combustion gases of a flat flame H2-air burner. Collisional broadening parameters for equilibrium mixtures of H2, O2, H2O, and N2 were obtained spanning a range of fuel/air equivalence ratios from 0.6 to 1.6 and temperatures from 1500 to 2050 K. Measurements were obtained spanning rotational quantum numbers from 4.5 to 16.5. The collision induced frequency shift was determined to be 0.1 that of the collisional broadening.

  17. Simplified Two-Time Step Method for Calculating Combustion Rates and Nitrogen Oxide Emissions for Hydrogen/Air and Hydorgen/Oxygen

    NASA Technical Reports Server (NTRS)

    Molnar, Melissa; Marek, C. John

    2005-01-01

    A simplified single rate expression for hydrogen combustion and nitrogen oxide production was developed. Detailed kinetics are predicted for the chemical kinetic times using the complete chemical mechanism over the entire operating space. These times are then correlated to the reactor conditions using an exponential fit. Simple first order reaction expressions are then used to find the conversion in the reactor. The method uses a two-time step kinetic scheme. The first time averaged step is used at the initial times with smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, temperature, and pressure. The second instantaneous step is used at higher water concentrations (> 1 x 10(exp -20) moles/cc) in the mixture which gives the chemical kinetic time as a function of the instantaneous fuel and water mole concentrations, pressure and temperature (T4). The simple correlations are then compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. This time is regressed over the complete initial conditions using the Excel regression routine. Chemical kinetic time equations for H2 and NOx are obtained for H2/air fuel and for the H2/O2. A similar correlation is also developed using data from NASA s Chemical Equilibrium Applications (CEA) code to determine the equilibrium temperature (T4) as a function of overall fuel/air ratio, pressure and initial temperature (T3). High values of the regression coefficient R2 are obtained.

  18. Summary of Simplified Two Time Step Method for Calculating Combustion Rates and Nitrogen Oxide Emissions for Hydrogen/Air and Hydrogen/Oxygen

    NASA Technical Reports Server (NTRS)

    Marek, C. John; Molnar, Melissa

    2005-01-01

    A simplified single rate expression for hydrogen combustion and nitrogen oxide production was developed. Detailed kinetics are predicted for the chemical kinetic times using the complete chemical mechanism over the entire operating space. These times are then correlated to the reactor conditions using an exponential fit. Simple first order reaction expressions are then used to find the conversion in the reactor. The method uses a two time step kinetic scheme. The first time averaged step is used at the initial times with smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, temperature, and pressure. The second instantaneous step is used at higher water concentrations (greater than l x 10(exp -20)) moles per cc) in the mixture which gives the chemical kinetic time as a function of the instantaneous fuel and water mole concentrations, pressure and temperature (T(sub 4)). The simple correlations are then compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. This time is regressed over the complete initial conditions using the Excel regression routine. Chemical kinetic time equations for H2 and NOx are obtained for H2/Air fuel and for H2/O2. A similar correlation is also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium temperature (T(sub 4)) as a function of overall fuel/air ratio, pressure and initial temperature (T(sub 3)). High values of the regression coefficient R squared are obtained.

  19. Inhalable particles and pulmonary host defense: in vivo and in vitro effects of ambient air and combustion particles.

    PubMed

    Hatch, G E; Boykin, E; Graham, J A; Lewtas, J; Pott, F; Loud, K; Mumford, J L

    1985-02-01

    The ability of particulate air pollutants (and possible constituents) to alter pulmonary host defenses was examined using an in vitro alveolar macrophage cytotoxicity assay and an in vivo bacterial infectivity screening test which employed intratracheal injection of the particles. A wide range of response between particles was seen at the 1.0-mg/ml level in vitro and the 0.1-mg/mouse level in vivo. A sample of fluidized-bed coal fly ash, bentonite, asbestos, some ambient air particles, and heavy metal oxides greatly increased susceptibility to pulmonary bacterial infection. Most coal fly ash samples and some air particles caused moderate increases in infectivity, while diesel particulates, volcanic ash, and crystalline silica caused only small increases. Cytotoxic effects on macrophages in vitro were observed with most of the particles. The in vivo and in vitro assays produced a similar ranking of toxicity; however, not all particles that were highly cytotoxic were potent in increasing bacterial infectivity. Increased toxicity measurable by either assay often appeared to be associated with small size or with the presence of metal in the particles. PMID:3967645

  20. Measurement of spray combustion processes

    NASA Technical Reports Server (NTRS)

    Peters, C. E.; Arman, E. F.; Hornkohl, J. O.; Farmer, W. M.

    1984-01-01

    A free jet configuration was chosen for measuring noncombusting spray fields and hydrocarbon-air spray flames in an effort to develop computational models of the dynamic interaction between droplets and the gas phase and to verify and refine numerical models of the entire spray combustion process. The development of a spray combustion facility is described including techniques for laser measurements in spray combustion environments and methods for data acquisition, processing, displaying, and interpretation.

  1. EMISSIONS ASSESSMENT OF CONVENTIONAL STATIONARY COMBUSTION SYSTEMS: VOLUME IV. COMMERCIAL/INSTITUTIONAL COMBUSTION SOURCES

    EPA Science Inventory

    The report characterizes air emissions from commercial/institutional external combustion sources and reciprocating engines and is the fourth of a series of five project reports characterizing emissions from conventional combustion sources. This characterization was based on a cri...

  2. Acoustic Emissions Reveal Combustion Conditions

    NASA Technical Reports Server (NTRS)

    Ramohalli, D. N. R.; Seshan, P. K.

    1983-01-01

    Turbulent-flame acoustic emissions change with air/fuel ratio variations. Acoustic emissions sensed and processed to detect inefficient operation; control system responds by adjusting fuel/air mixture for greater efficiency. Useful for diagnosis of combustion processes and fuel/air control.

  3. Combustion noise

    NASA Technical Reports Server (NTRS)

    Strahle, W. C.

    1977-01-01

    A review of the subject of combustion generated noise is presented. Combustion noise is an important noise source in industrial furnaces and process heaters, turbopropulsion and gas turbine systems, flaring operations, Diesel engines, and rocket engines. The state-of-the-art in combustion noise importance, understanding, prediction and scaling is presented for these systems. The fundamentals and available theories of combustion noise are given. Controversies in the field are discussed and recommendations for future research are made.

  4. Seasonal, anthropogenic, air mass, and meteorological influences on the atmospheric concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs): Evidence for the importance of diffuse combustion sources

    SciTech Connect

    Lee, R.G.M.; Green, N.J.L.; Lohmann, R.; Jones, K.C.

    1999-09-01

    Sampling programs were undertaken to establish air polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) concentrations at a semirural site on the northwest coast of England in autumn and summer and to investigate factors causing their variability. Changing source inputs, meteorological parameters, air masses, and the impact of a festival when it is customary to light fireworks and bonfires were investigated. Various lines of evidence from the study point to diffuse, combustion-related sources being a major influence on ambient air concentrations. Higher PCDD/F concentrations were generally associated with air masses that had originated and moved over land, particularly during periods of low ambient temperature. Low concentrations were associated with air masses that had arrived from the Atlantic Ocean/Irish Sea to the west of the sampling site and had little or no contact with urban/industrialized areas. Concentrations in the autumn months were 2 to 10 times higher than those found in the summer.

  5. Demonstration of Air-Power-Assist Engine Technology for Clean Combustion and Direct Energy Recovery in Heavy Duty Application

    SciTech Connect

    Hyungsuk Kang; Chun Tai

    2010-05-01

    The first phase of the project consists of four months of applied research, starting from September 1, 2005 and was completed by December 31, 2005. During this time, the project team heavily relied on highly detailed numerical modeling techniques to evaluate the feasibility of the APA technology. Specifically, (i) A GT-Power{sup TM}engine simulation model was constructed to predict engine efficiency at various operating conditions. Efficiency was defined based on the second-law thermodynamic availability. (ii) The engine efficiency map generated by the engine simulation was then fed into a simplified vehicle model, which was constructed in the Matlab/Simulink environment, to predict fuel consumption of a refuse truck on a simple collection cycle. (iii) Design and analysis work supporting the concept of retrofitting an existing Sturman Industries Hydraulic Valve Actuation (HVA) system with the modifications that are required to run the HVA system with Air Power Assist functionality. A Matlab/Simulink model was used to calculate the dynamic response of the HVA system. Computer aided design (CAD) was done in Solidworks for mechanical design and hydraulic layout. At the end of Phase I, 11% fuel economy improvement was predicted. During Phase II, the engine simulation group completed the engine mapping work. The air handling group made substantial progress in identifying suppliers and conducting 3D modelling design. Sturman Industries completed design modification of the HVA system, which was reviewed and accepted by Volvo Powertrain. In Phase II, the possibility of 15% fuel economy improvement was shown with new EGR cooler design by reducing EGR cooler outlet temperature with APA engine technology from Air Handling Group. In addition, Vehicle Simulation with APA technology estimated 4 -21% fuel economy improvement over a wide range of driving cycles. During Phase III, the engine experimental setup was initiated at VPTNA, Hagerstown, MD. Air Handling system and HVA

  6. The contributions of emissions and spatial microenvironments to exposure to indoor air pollution from biomass combustion in Kenya.

    PubMed Central

    Ezzati, M; Saleh, H; Kammen, D M

    2000-01-01

    Acute and chronic respiratory diseases, which are causally linked to exposure to indoor air pollution in developing countries, are the leading cause of global morbidity and mortality. Efforts to develop effective intervention strategies and detailed quantification of the exposure-response relationship for indoor particulate matter require accurate estimates of exposure. We used continuous monitoring of indoor air pollution and individual time-activity budget data to construct detailed profiles of exposure for 345 individuals in 55 households in rural Kenya. Data for analysis were from two hundred ten 14-hour days of continuous real-time monitoring of concentrations of particulate matter [less than/equal to] 10 microm in aerodynamic diameter and the location and activities of household members. These data were supplemented by data on the spatial dispersion of pollution and from interviews. Young and adult women had not only the highest absolute exposure to particulate matter (2, 795 and 4,898 microg/m(3) average daily exposure concentrations, respectively) but also the largest exposure relative to that of males in the same age group (2.5 and 4.8 times, respectively). Exposure during brief high-intensity emission episodes accounts for 31-61% of the total exposure of household members who take part in cooking and 0-11% for those who do not. Simple models that neglect the spatial distribution of pollution within the home, intense emission episodes, and activity patterns underestimate exposure by 3-71% for different demographic subgroups, resulting in inaccurate and biased estimations. Health and intervention impact studies should therefore consider in detail the critical role of exposure patterns, including the short periods of intense emission, to avoid spurious assessments of risks and benefits. PMID:11017887

  7. Sensitivity of hazardous air pollutant emissions to the combustion of blends of petroleum diesel and biodiesel fuel

    NASA Astrophysics Data System (ADS)

    Magara-Gomez, Kento T.; Olson, Michael R.; Okuda, Tomoaki; Walz, Kenneth A.; Schauer, James J.

    2012-04-01

    Emission rates and composition of known hazardous air pollutants in the exhaust gas from a commercial agriculture tractor, burning a range of biodiesel blends operating at two different load conditions were investigated to better understand the emission characteristics of biodiesel fuel. Ultra-Low Sulfur Petroleum Diesel (ULSD) fuel was blended with soybean oil and beef tallow based biodiesel to examine fuels containing 0% (B0), 50% (B50) and 100% (B100) soybean oil based biodiesel, and 50% (B50T) and 100% (B100T) beef tallow biodiesel. Samples were collected using a dilution source sampler to simulate atmospheric dilution. Particulate matter and exhaust gases were analyzed for carbonyls, Volatile Organic Compounds (VOCs), and Polycyclic Aromatic Hydrocarbons (PAHs) to determine their respective emission rates. This analysis is focused on the emissions of organic compounds classified by the US EPA as air toxics and include 2,2,4 trimethylpentane, benzene, toluene, ethylbenzene, m-, p- and o-xylene, formaldehyde, acetaldehyde and methylethyl ketone. Emission rates of 2,2,4 trimethylpentane, toluene, ethylbenzene, m-, p- and o-xylene decreased more than 90% for B50, B100 and B100T blends; decreases in emission rates of benzene, formaldehyde and acetaldehyde were more modest, producing values between 23 and 67%, and methyl ethyl ketone showed decreases not exceeding 7% for the studied biodiesel blends. PAHs emission rates were reduced by 66% for B50, 84% for B100, and by 89% for B100T. The overall emissions of toxic organic compounds were calculated and expressed as benzene equivalents. The largest contributors of toxic risk were found to be formaldehyde and acetaldehyde. Reductions in formaldehyde emissions were 23% for B50 and 42% for B100 soybean, and 40% for B100T beef tallow compared to B0. Similarly, acetaldehyde reductions were 34% for B50 and 53% for B100 soybean biodiesel and 42% for B100T beef tallow biodiesel.

  8. The 33rd JANNAF Combustion Subcommittee Meeting. Volume 2

    NASA Technical Reports Server (NTRS)

    Fry, Ronald S. (Editor); Gannaway, Mary T. (Editor)

    1996-01-01

    This volume, the second of four volumes, is a collection of 48 unclassified/unlimited papers which were presented at the 33rd Joint Army-Navy-NASA-Air Force (JANNAF) Combustion Subcommittee Meeting conjunction with the Propulsion Systems Hazards Subcommittee held 4-8 November 1996 at the Naval Postgraduate School, Monterey, CA. The JANNAF papers contained in this volume review many areas of solid propellant combustion to include combustion fundamentals, combustion instability fundamentals and combustion instability applied to motors, AP combustion, Nitramine combustion, metal combustion, kinetics and spectroscopy and combustion topics of broad general interest.

  9. Numerical study of hydrogen-air supersonic combustion by using elliptic and parabolized equations. Progress report, 1 December 1985-31 May 1986

    SciTech Connect

    Chitsomboon, T.; Tiwari, S.N.

    1986-08-01

    The two-dimensional Navier-Stokes and species continuity equations are used to investigate supersonic chemically reacting flow problems which are related to scramjet-engine configurations. A global two-step finite-rate chemistry model is employed to represent the hydrogen-air combustion in the flow. An algebraic turbulent model is adopted for turbulent flow calculations. The explicit unsplit MacCormack finite-difference algorithm is used to develop a computer program suitable for a vector processing computer. The computer program developed is then used to integrate the system of the governing equations in time until convergence is attained. The chemistry source terms in the species continuity equations are evaluated implicitly to alleviate stiffness associated with fast chemical reactions. The problems solved by the elliptic code are re-investigated by using a set of two-dimensional parabolized Navier-Stokes and species equations. A linearized fully-coupled fully-implicit finite difference algorithm is used to develop a second computer code which solves the governing equations by marching in spce rather than time, resulting in a considerable saving in computer resources. Results obtained by using the parabolized formulation are compared with the results obtained by using the fully-elliptic equations. The comparisons indicate fairly good agreement of the results of the two formulations.

  10. APTI Course 427, Combustion Evaluation. Student Workbook.

    ERIC Educational Resources Information Center

    Beard, J. Taylor; And Others

    Presented are exercises intended to supplement course work in air pollution control, specifically as they relate to combustion. Chapters offered in this workbook include: (1) Combustion Calculations, (2) Combustion System Design Problems, (3) Emission Calculations I, (4) Emission Calculations II, (5) Afterburner Design Problems, and (6) Cumbustion…

  11. Numerical Analysis of Autoignition and Combustion of n-Butane and Air Mixture in Homogeneous-Charge Compression-Ignition Engine Using Elementary Reactions

    NASA Astrophysics Data System (ADS)

    Yamasaki, Yudai; Iida, Norimasa

    The present study focuses on clarifying the combustion mechanism of the homogeneous-charge compression-ignition (HCCI) engine in order to control ignition and combustion as well as to reduce HC and CO emissions and to maintain high combustion efficiency by calculating the chemical kinetics of elementary reactions. For the calculations, n-butane was selected as fuel since it is a fuel with the smallest carbon number in the alkane family that shows two-stage autoignition (heat release with low-temperature reaction (LTR) and with high-temperature reaction (HTR)) similarly to higher hydrocarbons such as gasoline. The CHEMKIN code was used for the calculations assuming zero dimensions in the combustion chamber and adiabatic change. The results reveal the heat release mechanism of the LTR and HTR, the control factor of ignition timing and combustion speed, and the condition need to reduce HC and CO emissions and to maintain high combustion efficiency.

  12. Oxy-combustion of pulverized coal : modeling of char-combustion kinetics.

    SciTech Connect

    Shaddix, Christopher R.; Haynes, Brian S.; Geier, Manfred

    2010-09-01

    In this study, char combustion of pulverized coal under oxy-fuel combustion conditions was investigated on the basis of experimentally observed temperature-size characteristics and corresponding predictions of numerical simulations. Using a combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometer, combustion characteristics (particle temperatures and apparent size) of pulverized coal char particles was determined for combustion in both reduced oxygen and oxygen-enriched atmospheres with either a N{sub 2} or CO{sub 2} bath gas. The two coals investigated were a low-sulfur, high-volatile bituminous coal (Utah Skyline) and a low-sulfur subbituminous coal (North Antelope), both size-classified to 75-106 {micro}m. A particular focus of this study lies in the analysis of the predictive modeling capabilities of simplified models that capture char combustion characteristics but exhibit the lowest possible complexity and thus facilitate incorporation in existing computational fluid dynamics (CFD) simulation codes. For this purpose, char consumption characteristics were calculated for char particles in the size range 10-200 {micro}m using (1) single-film, apparent kinetic models with a chemically 'frozen' boundary layer, and (2) a reacting porous particle model with detailed gas-phase kinetics and three separate heterogeneous reaction mechanisms of char-oxidation and gasification. A comparison of model results with experimental data suggests that single-film models with reaction orders between 0.5 and 1 with respect to the surface oxygen partial pressure may be capable of adequately predicting the temperature-size characteristics of char consumption, provided heterogeneous (steam and CO{sub 2}) gasification reactions are accounted for.

  13. Oxy-combustion of pulverized coal : modeling of char combustion kinetics.

    SciTech Connect

    Shaddix, Christopher R.; Haynes, Brian S.; Geier, Manfred

    2010-09-01

    In this study, char combustion of pulverized coal under oxy-fuel combustion conditions was investigated on the basis of experimentally observed temperature-size characteristics and corresponding predictions of numerical simulations. Using a combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometer, combustion characteristics (particle temperatures and apparent size) of pulverized coal char particles was determined for combustion in both reduced oxygen and oxygen-enriched atmospheres with either a N{sub 2} or CO{sub 2} bath gas. The two coals investigated were a low-sulfur, high-volatile bituminous coal (Utah Skyline) and a low-sulfur subbituminous coal (North Antelope), both size-classified to 75-106 {micro}m. A particular focus of this study lies in the analysis of the predictive modeling capabilities of simplified models that capture char combustion characteristics but exhibit the lowest possible complexity and thus facilitate incorporation in existing computational fluid dynamics (CFD) simulation codes. For this purpose, char consumption characteristics were calculated for char particles in the size range 10-200 {micro}m using (1) single-film, apparent kinetic models with a chemically 'frozen' boundary layer, and (2) a reacting porous particle model with detailed gas-phase kinetics and three separate heterogeneous reaction mechanisms of char-oxidation and gasification. A comparison of model results with experimental data suggests that single-film models with reaction orders between 0.5 and 1 with respect to the surface oxygen partial pressure may be capable of adequately predicting the temperature-size characteristics of char consumption, provided heterogeneous (steam and CO{sub 2}) gasification reactions are accounted for.

  14. Combustion appliance with a safety device

    SciTech Connect

    Furumai, K.; Indo, M.; Kawabata, N.; Tanaka, E.

    1982-11-09

    There is provided a combustion appliance with a safety device. An oxygen partial pressure sensor made up of a transition metal oxide or rare earth metal oxide is normally disposed in a position in which the excess air ratio downstream of a flame formed by a burner can be detected and, at times of abnormality, within the flame. The resistance change of said oxygen partial pressure is detected and the combustion is stopped when incomplete combustion occurs due to oxygen depression, clogging of the primary air orifice of the burner or clogging of the combustion chamber with the products of combustion.

  15. Internal combustion engine using premixed combustion of stratified charges

    DOEpatents

    Marriott, Craig D.; Reitz, Rolf D. (Madison, WI

    2003-12-30

    During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

  16. Exposure to Household Air Pollution from Wood Combustion and Association with Respiratory Symptoms and Lung Function in Nonsmoking Women: Results from the RESPIRE Trial, Guatemala

    PubMed Central

    Diaz, Esperanza; Smith-Sivertsen, Tone; Lie, Rolv T.; Bakke, Per; Balmes, John R.; Smith, Kirk R.; Bruce, Nigel G.

    2014-01-01

    exposure to particulate matter against lung function will help us understand more fully the impact of HAP on COPD. Citation: Pope D, Diaz E, Smith-Sivertsen T, Lie RT, Bakke P, Balmes JR, Smith KR, Bruce NG. 2015. Exposure to household air pollution from wood combustion and association with respiratory symptoms and lung function in nonsmoking women: results from the RESPIRE Trial, Guatemala. Environ Health Perspect 123:285–292; http://dx.doi.org/10.1289/ehp.1408200 PMID:25398189

  17. Combustion 2000

    SciTech Connect

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  18. Fluidized bed combustion of coal

    NASA Astrophysics Data System (ADS)

    Tatebayashi, J.; Okada, Y.; Yano, K.; Takada, T.; Handa, K.

    The effect of various parameters on combustion efficiency, desulfurization efficiency and NO emission in fluidized bed combustion of coal were investigated by using two test combustors whose sectional areas were 200 mm and 500 mm square. It has been revealed that by employing two-stage combustion and setting the primary air ratio, secondary air injection height and other parameters to optimum levels, NO emission can be greatly reduced while barely impairing combustion efficiency or desulfurization efficiency. Also, NO emission of less than 50 ppm and desulfurization efficiency of as high as 93% were achieved. These results have ensured good prospects for the development of a coal combustion boiler system which can satisfy the strictest environmental protection regulations, without installing special desulfurization and de-NO(X) facilities.

  19. Hydrogen combustion in a hypersonic airstream

    NASA Technical Reports Server (NTRS)

    Casey, R. T.; Stalker, R. J.; Brescianini, C.

    1992-01-01

    An experimental and computational investigation of hypervelocity, hypersonic combustion of hydrogen with air is described which was intended to confirm the presence of combustion at these conditions and then to gauge the pressure rise associated with the heat release of combustion. Experiments were conducted in a square cross section duct and wall pressure was measured. It was found that combustion did occur and that the maximum pressure increase was approximately 72 percent over the intake pressure.

  20. Study of a blast-furnace smelting technology which involves the injection of pulverized-coal fuel, natural gas, and an oxygen-enriched blast into the hearth

    SciTech Connect

    Ryzhenkov, A.N.; Yaroshevskii, S.L.; Zamuruev, V.P.; Popov, V.E.; Afanas'eva, Z.K.

    2006-05-15

    Studies were made of features of a blast-furnace smelting technology that involves the injection of natural gas (NG), oxygen (O{sub 2}) and pulverized-coal fuel (PCF) into the hearth. The technology has been implemented in the compensation and overcompensation regimes, which has made it possible to maintain or improve the gas dynamics of the furnace, the conditions for the reduction of iron oxides, the heating of the charge, and PCF combustion in the tuyere zone as PCF consumption is increased and coke use is decreased. Under the given conditions, with the blast having an oxygen content of 25.64-25.7%, the hearth injection of 131-138 kg PCF and 65-69 m{sup 3} NG for each ton of pig iron has made it possible to reduce coke consumption by 171-185 kg/ton pig (30.2-32.7%), reduce the consumption of comparison fuel by 36-37 kg/ton (5.2-5.3%), and lower the production cost of the pig iron by 43-49 hryvnas/ton (3.7-6.4%). Here, furnace productivity has increased 3.8-6.5%, while the quality of the conversion pig iron remains the same as before. Measures are being implemented to further increase the level and efficiency of PCF use.

  1. Coal combustion system

    DOEpatents

    Wilkes, Colin; Mongia, Hukam C.; Tramm, Peter C.

    1988-01-01

    In a coal combustion system suitable for a gas turbine engine, pulverized coal is transported to a rich zone combustor and burned at an equivalence ratio exceeding 1 at a temperature above the slagging temperature of the coal so that combustible hot gas and molten slag issue from the rich zone combustor. A coolant screen of water stretches across a throat of a quench stage and cools the combustible gas and molten slag to below the slagging temperature of the coal so that the slag freezes and shatters into small pellets. The pelletized slag is separated from the combustible gas in a first inertia separator. Residual ash is separated from the combustible gas in a second inertia separator. The combustible gas is mixed with secondary air in a lean zone combustor and burned at an equivalence ratio of less than 1 to produce hot gas motive at temperature above the coal slagging temperature. The motive fluid is cooled in a dilution stage to an acceptable turbine inlet temperature before being transported to the turbine.

  2. Device for improved combustion

    SciTech Connect

    Polomchak, R.W.; Yacko, M.

    1988-03-08

    A device for improved combustion is described comprising: a tubular housing member having a first end and a second end, the first and second ends each having a circular opening therethrough; a combustion chamber disposed about the second end of the-tubular-housing member; a first conduit member extending from the first end of the tubular housing member and in fluid communication with the circular opening in the first end of the tubular housing member so as to allow the passage of air therethrough; a second conduit member axially disposed within the first conduit member and extending through the first conduit member and through the tubular housing member to the circular opening the second end of the tubular housing member so as to allow the passage of fuel therethrough; means for effecting turbulence in the air passing through the tubular housing member; means for effecting turbulence in the fuel passing through the second conduit member; means for intermixing and emitting the turbulent air and the fuel in a mushroom shaped configuration with the turbulent air surrounding the mushroom shaped configuration so as to substantially eliminate noxious waste gases as by-product of combustion of the air and fuel mixture.

  3. Computational Combustion

    SciTech Connect

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

    2004-08-26

    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  4. Compressed air energy storage system

    SciTech Connect

    Ahrens, F.W.; Kartsounes, G.T.

    1981-07-28

    An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustible fuel. Preferably the internal combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

  5. Compressed air energy storage system

    DOEpatents

    Ahrens, Frederick W.; Kartsounes, George T.

    1981-01-01

    An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustible fuel. Preferably the internal combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

  6. Chamberless residential warm air furnace design

    SciTech Connect

    Godfree, J.

    1996-07-01

    This brief paper is an introduction to the concept of designing residential warm air furnaces without combustion chambers. This is possible since some small burners do not require the thermal support of a combustion chamber to complete the combustion process.

  7. Fluidized-bed combustion

    SciTech Connect

    Botros, P E

    1990-04-01

    This report describes the activities of the Morgantown Energy Technology Center's research and development program in fluidized-bed combustion from October 1, 1987, to September 30, 1989. The Department of Energy program involves atmospheric and pressurized systems. Demonstrations of industrial-scale atmospheric systems are being completed, and smaller boilers are being explored. These systems include vortex, multi-solid, spouted, dual-sided, air-cooled, pulsed, and waste-fired fluidized-beds. Combustion of low-rank coal, components, and erosion are being studied. In pressurized combustion, first-generation, combined-cycle power plants are being tested, and second-generation, advanced-cycle systems are being designed and cost evaluated. Research in coal devolatilization, metal wastage, tube corrosion, and fluidization also supports this area. 52 refs., 24 figs., 3 tabs.

  8. Catalytic combustion with steam injection

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.; Tacina, R. R.

    1982-01-01

    The effects of steam injection on (1) catalytic combustion performance, and (2) the tendency of residual fuel to burn in the premixing duct upstream of the catalytic reactor were determined. A petroleum residual, no. 2 diesel, and a blend of middle and heavy distillate coal derived fuels were tested. Fuel and steam were injected together into the preheated airflow entering a 12 cm diameter catalytic combustion test section. The inlet air velocity and pressure were constant at 10 m/s and 600 kPa, respectively. Steam flow rates were varied from 24 percent to 52 percent of the air flow rate. The resulting steam air mixture temperatures varied from 630 to 740 K. Combustion temperatures were in the range of 1200 to 1400 K. The steam had little effect on combustion efficiency or emissions. It was concluded that the steam acts as a diluent which has no adverse effect on catalytic combustion performance for no. 2 diesel and coal derived liquid fuels. Tests with the residual fuel showed that upstream burning could be eliminated with steam injection rates greater than 30 percent of the air flow rate, but inlet mixture temperatures were too low to permit stable catalytic combustion of this fuel.

  9. Microgravity Smoldering Combustion Takes Flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Microgravity Smoldering Combustion (MSC) experiment lifted off aboard the Space Shuttle Endeavour in September 1995 on the STS-69 mission. This experiment is part of series of studies focused on the smolder characteristics of porous, combustible materials in a microgravity environment. Smoldering is a nonflaming form of combustion that takes place in the interior of combustible materials. Common examples of smoldering are nonflaming embers, charcoal briquettes, and cigarettes. The objective of the study is to provide a better understanding of the controlling mechanisms of smoldering, both in microgravity and Earth gravity. As with other forms of combustion, gravity affects the availability of air and the transport of heat, and therefore, the rate of combustion. Results of the microgravity experiments will be compared with identical experiments carried out in Earth's gravity. They also will be used to verify present theories of smoldering combustion and will provide new insights into the process of smoldering combustion, enhancing our fundamental understanding of this frequently encountered combustion process and guiding improvement in fire safety practices.

  10. Utilization of coal mine ventilation exhaust as combustion air in gas-fired turbines for electric and/or mechanical power generation. Semi-annual topical report, June 1995--August 1995

    SciTech Connect

    1995-12-01

    Methane emitted during underground coal mining operations is a hazard that is dealt with by diluting the methane with fresh air and exhausting the contaminated air to the atmosphere. Unfortunately this waste stream may contain more than 60% of the methane resource from the coal, and in the atmosphere the methane acts as a greenhouse gas with an effect about 24.5 times greater than CO{sub 2}. Though the waste stream is too dilute for normal recovery processes, it can be used as combustion air for a turbine-generator, thereby reducing the turbine fuel requirements while reducing emissions. Preliminary analysis indicates that such a system, built using standard equipment, is economically and environmentally attractive, and has potential for worldwide application.

  11. WHO indoor air quality guidelines on household fuel combustion: Strategy implications of new evidence on interventions and exposure-risk functions

    NASA Astrophysics Data System (ADS)

    Bruce, Nigel; Pope, Dan; Rehfuess, Eva; Balakrishnan, Kalpana; Adair-Rohani, Heather; Dora, Carlos

    2015-04-01

    Background: 2.8 billion people use solid fuels as their primary cooking fuel; the resulting high levels of household air pollution (HAP) were estimated to cause more than 4 million premature deaths in 2012. The people most affected are among the world's poorest, and past experience has shown that securing adoption and sustained use of effective, low-emission stove technologies and fuels in such populations is not easy. Among the questions raised by these challenges are (i) to what levels does HAP exposure need to be reduced in order to ensure that substantial health benefits are achieved, and (ii) what intervention technologies and fuels can achieve the required levels of HAP in practice? New WHO air quality guidelines are being developed to address these issues. Aims: To address the above questions drawing on evidence from new evidence reviews conducted for the WHO guidelines. Methods: Discussion of key findings from reviews covering (i) systematic reviews of health risks from HAP exposure, (ii) newly developed exposure-response functions which combine combustion pollution risk evidence from ambient air pollution, second-hand smoke, HAP and active smoking, and (iii) a systematic review of the impacts of solid fuel and clean fuel interventions on kitchen levels of, and personal exposure to, PM2.5 and carbon monoxide (CO). Findings: Evidence on health risks from HAP suggest that controlling this exposure could reduce the risk of multiple child and adult health outcomes by 20-50%. The new integrated exposure-response functions (IERs) indicate that in order to secure these benefits, HAP levels require to be reduced to the WHO IT-1 annual average level (35 μg/m3 PM2.5), or below. The second review found that, in practice, solid fuel 'improved stoves' led to large percentage and absolute reductions, but post-intervention kitchen levels were still very high, at several hundreds of μg/m3 of PM2.5, although most solid fuel stove types met the WHO 24-hr average guideline

  12. Some Factors Affecting Combustion in an Internal-Combustion Engine

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Cohn, Mildred

    1936-01-01

    An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

  13. High efficiency RCCI combustion

    NASA Astrophysics Data System (ADS)

    Splitter, Derek A.

    An experimental investigation of the pragmatic limits of Reactivity Controlled Compression Ignition (RCCI) engine efficiency was performed. The study utilized engine experiments combined with zero-dimensional modeling. Initially, simulations were used to suggest conditions of high engine efficiency with RCCI. Preliminary simulations suggested that high efficiency could be obtained by using a very dilute charge with a high compression ratio. Moreover, the preliminary simulations further suggested that with simultaneous 50% reductions in heat transfer and incomplete combustion, 60% gross thermal efficiency may be achievable with RCCI. Following the initial simulations, experiments to investigate the combustion process, fuel effects, and methods to reduce heat transfer and incomplete combustion reduction were conducted. The results demonstrated that the engine cycle and combustion process are linked, and if high efficiency is to be had, then the combustion event must be tailored to the initial cycle conditions. It was found that reductions to engine heat transfer are a key enabler to increasing engine efficiency. In addition, it was found that the piston oil jet gallery cooling in RCCI may be unnecessary, as it had a negative impact on efficiency. Without piston oil gallery cooling, it was found that RCCI was nearly adiabatic, achieving 95% of the theoretical maximum cycle efficiency (air standard Otto cycle efficiency).

  14. Fluidized bed combustion

    SciTech Connect

    Sowards, N.K.; Murphy, M.L.

    1992-04-07

    This patent describes a method of incinerating a fuel containing difficult to remove tramp comprising wire. It comprises placing of a fluid bed within a downwardly and inwardly tapered centrally hollow air distributor disposed within a lower portion of a vessel; introducing fuel comprising combustible material and tramp comprising wire into the fluid bed; incinerating the combustible material in the fluid bed accommodating downward migration within the fluid bed of the wire without a central obstruction to such migration; in the course of performing the incinerating step, fluidizing the bed solely by introducing inwardly at several tiered locations directed air into the bed only around the tapered periphery along the lower portion of the vessel from a plurality of inwardly and downwardly parallel sites as causing the bed material and tramp to migrate downwardly and inwardly without central bed obstruction toward a discharge site.

  15. Controlling Indoor Air Pollution.

    ERIC Educational Resources Information Center

    Nero, Anthony V, Jr.

    1988-01-01

    Discusses the health risks posed by indoor air pollutants, such as airborne combustion products, toxic chemicals, and radioactivity. Questions as to how indoor air might be regulated. Calls for new approaches to environmental protection. (TW)

  16. Combustion-gas recirculation system

    DOEpatents

    Baldwin, Darryl Dean

    2007-10-09

    A combustion-gas recirculation system has a mixing chamber with a mixing-chamber inlet and a mixing-chamber outlet. The combustion-gas recirculation system may further include a duct connected to the mixing-chamber inlet. Additionally, the combustion-gas recirculation system may include an open inlet channel with a solid outer wall. The open inlet channel may extend into the mixing chamber such that an end of the open inlet channel is disposed between the mixing-chamber inlet and the mixing-chamber outlet. Furthermore, air within the open inlet channel may be at a pressure near or below atmospheric pressure.

  17. Oxygen enhanced switching to combustion of lower rank fuels

    DOEpatents

    Kobayashi, Hisashi; Bool, III, Lawrence E.; Wu, Kuang Tsai

    2004-03-02

    A furnace that combusts fuel, such as coal, of a given minimum energy content to obtain a stated minimum amount of energy per unit of time is enabled to combust fuel having a lower energy content, while still obtaining at least the stated minimum energy generation rate, by replacing a small amount of the combustion air fed to the furnace by oxygen. The replacement of oxygen for combustion air also provides reduction in the generation of NOx.

  18. Combustion detector

    NASA Technical Reports Server (NTRS)

    Trimpi, R. L.; Nealy, J. E.; Grose, W. L. (Inventor)

    1973-01-01

    A device has been developed for generating a rapid response signal upon the radiation-emitting combustion reaction of certain gases in order to provide a means for the detection and identification of such reaction and concurrently discriminate against spurious signals. This combustion might be the first stage of a coal mine explosion process, and thereby this device could provide a warning of the impending explosion in time to initiate quenching action. This device has the capability of distinguishing between the light emitted from a combustion reaction and the light emitted by miners' lamps, electric lamps, welding sparks or other spurious events so that the quenching mechanism is triggered only when an explosion-initiating combustion occurs.

  19. Promoted Combustion of Metals in a High-Pressure, Flowing Oxygen Environment

    NASA Technical Reports Server (NTRS)

    Maes, M. J.; Stoltzfus, J. M.

    2001-01-01

    Traditional promoted combustion testing has used 0.125 inch diameter samples that are ignited in a pressurized, oxygen-enriched environment. Many years of testing this sample size have yielded useful data regarding threshold pressure, or the minimum oxygen pressure required to support self-sustained combustion. However, when a material is tested in a flowing system, the threshold pressure changes. White Sands Test Facility has developed a test system to burn samples in flowing gaseous oxygen. Current sample configurations are 0.5 inch diameter rods and 1.25 inch diameter pipes with pressures ranging up to 2000 psi and gas velocities reaching 200 ft/s. This paper describes the test apparatus, modifications made as the result of a fire, and a description of the tests currently being performed.

  20. High efficiency power generation from coal and wastes utilizing high temperature air combustion technology (Part 1: Performance of pebble bed gasifier for coal and wastes)

    SciTech Connect

    Kosaka, Hitoshi; Iwahashi, Takashi; Yoshida, Nobuhiro; Tsuji, Kiyoshi; Yoshikawa, Kunio; Kiga, Takashi; Tamamushi, Fumihiro; Makino, Kenji; Oonish, Hiroshi

    1998-07-01

    A new concept of a gasifier for coal and wastes is proposed where entrained bed and fixed pebble bed are combined. Main features of this pebble bed gasifier are high efficiency molten slag capture, high efficiency gasification and compactness. Coal and RFD combustion experiments using the pebble bed gasifier demonstrated high efficiency capture and continuous extraction of molten slag as well as complete char combustion with extra ordinarily short residence time of pulverized coal and crushed RDF at the temperature level of about 1,500 C within the pebble bed. Durability tests using high temperature electric furnace has shown that high density alumna is a good candidate for pebble material.

  1. Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

    PubMed

    Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

    2010-02-01

    Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers. PMID:20050661

  2. Survey of Hydrogen Combustion Properties

    NASA Technical Reports Server (NTRS)

    Drell, Isadore L; Belles, Frank E

    1958-01-01

    This literature digest of hydrogen-air combustion fundamentals presents data on flame temperature, burning velocity, quenching distance, flammability limits, ignition energy, flame stability, detonation, spontaneous ignition, and explosion limits. The data are assessed, recommended values are given, and relations among various combustion properties are discussed. New material presented includes: theoretical treatment of variation in spontaneous ignition lag with temperature, pressure, and composition, based on reaction kinetics of hydrogen-air composition range for 0.01 to 100 atmospheres and initial temperatures of 0 degrees to 1400 degrees k.

  3. Spherical combustion clouds in explosions

    NASA Astrophysics Data System (ADS)

    Kuhl, A. L.; Bell, J. B.; Beckner, V. E.; Balakrishnan, K.; Aspden, A. J.

    2013-05-01

    This study explores the properties of spherical combustion clouds in explosions. Two cases are investigated: (1) detonation of a TNT charge and combustion of its detonation products with air, and (2) shock dispersion of aluminum powder and its combustion with air. The evolution of the blast wave and ensuing combustion cloud dynamics are studied via numerical simulations with our adaptive mesh refinement combustion code. The code solves the multi-phase conservation laws for a dilute heterogeneous continuum as formulated by Nigmatulin. Single-phase combustion (e.g., TNT with air) is modeled in the fast-chemistry limit. Two-phase combustion (e.g., Al powder with air) uses an induction time model based on Arrhenius fits to Boiko's shock tube data, along with an ignition temperature criterion based on fits to Gurevich's data, and an ignition probability model that accounts for multi-particle effects on cloud ignition. Equations of state are based on polynomial fits to thermodynamic calculations with the Cheetah code, assuming frozen reactants and equilibrium products. Adaptive mesh refinement is used to resolve thin reaction zones and capture the energy-bearing scales of turbulence on the computational mesh (ILES approach). Taking advantage of the symmetry of the problem, azimuthal averaging was used to extract the mean and rms fluctuations from the numerical solution, including: thermodynamic profiles, kinematic profiles, and reaction-zone profiles across the combustion cloud. Fuel consumption was limited to ˜ 60-70 %, due to the limited amount of air a spherical combustion cloud can entrain before the turbulent velocity field decays away. Turbulent kinetic energy spectra of the solution were found to have both rotational and dilatational components, due to compressibility effects. The dilatational component was typically about 1 % of the rotational component; both seemed to preserve their spectra as they decayed. Kinetic energy of the blast wave decayed due to the

  4. Calculation of gas temperature at the outlet of the combustion chamber and in the air-gas channel of a gas-turbine unit by data of acceptance tests in accordance with ISO

    NASA Astrophysics Data System (ADS)

    Kostyuk, A. G.; Karpunin, A. P.

    2016-01-01

    This article describes a high accuracy method enabling performance of the calculation of real values of the initial temperature of a gas turbine unit (GTU), i.e., the gas temperature at the outlet of the combustion chamber, in a situation where manufacturers do not disclose this information. The features of the definition of the initial temperature of the GTU according to ISO standards were analyzed. It is noted that the true temperatures for high-temperature GTUs is significantly higher than values determined according to ISO standards. A computational procedure for the determination of gas temperatures in the air-gas channel of the gas turbine and cooling air consumptions over blade rims is proposed. As starting equations, the heat balance equation and the flow mixing equation for the combustion chamber are assumed. Results of acceptance GTU tests according to ISO standards and statistical dependencies of required cooling air consumptions on the gas temperature and the blade metal are also used for calculations. An example of the calculation is given for one of the units. Using a developed computer program, the temperatures in the air-gas channel of certain GTUs are calculated, taking into account their design features. These calculations are performed on the previously published procedure for the detailed calculation of the cooled gas turbine subject to additional losses arising because of the presence of the cooling system. The accuracy of calculations by the computer program is confirmed by conducting verification calculations for the GTU of the Mitsubishi Comp. and comparing results with published data of the company. Calculation data for temperatures were compared with the experimental data and the characteristics of the GTU, and the error of the proposed method is estimated.

  5. Jet plume injection and combustion system for internal combustion engines

    DOEpatents

    Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

    1993-01-01

    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

  6. Jet plume injection and combustion system for internal combustion engines

    DOEpatents

    Oppenheim, A.K.; Maxson, J.A.; Hensinger, D.M.

    1993-12-21

    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure. 24 figures.

  7. Jet plume injection and combustion system for internal combustion engines

    SciTech Connect

    Oppenheim, A.K.; Maxson, J.A.; Hensinger, D.M.

    1992-12-31

    This invention is comprised of an improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

  8. Combustion chamber and thermal vapor stream producing apparatus and method

    DOEpatents

    Sperry, John S.; Krajicek, Richard W.; Cradeur, Robert R.

    1978-01-01

    A new and improved method and apparatus for burning a hydrocarbon fuel for producing a high pressure thermal vapor stream comprising steam and combustion gases for injecting into a subterranean formation for the recovery of liquefiable minerals therefrom, wherein a high pressure combustion chamber having multiple refractory lined combustion zones of varying diameters is provided for burning a hydrocarbon fuel and pressurized air in predetermined ratios injected into the chamber for producing hot combustion gases essentially free of oxidizing components and solid carbonaceous particles. The combustion zones are formed by zones of increasing diameters up a final zone of decreasing diameter to provide expansion zones which cause turbulence through controlled thorough mixing of the air and fuel to facilitate complete combustion. The high pressure air and fuel is injected into the first of the multiple zones where ignition occurs with a portion of the air injected at or near the point of ignition to further provide turbulence and more complete combustion.

  9. Biofuels combustion*

    DOE PAGESBeta

    Westbrook, Charles K.

    2013-01-04

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acidsmore » and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.« less

  10. Biofuels Combustion

    NASA Astrophysics Data System (ADS)

    Westbrook, Charles K.

    2013-04-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  11. Biofuels combustion*

    SciTech Connect

    Westbrook, Charles K.

    2013-01-04

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.

  12. Bubble Combustion

    NASA Technical Reports Server (NTRS)

    Corrigan, Jackie

    2004-01-01

    A method of energy production that is capable of low pollutant emissions is fundamental to one of the four pillars of NASA s Aeronautics Blueprint: Revolutionary Vehicles. Bubble combustion, a new engine technology currently being developed at Glenn Research Center promises to provide low emissions combustion in support of NASA s vision under the Emissions Element because it generates power, while minimizing the production of carbon dioxide (CO2) and nitrous oxides (NOx), both known to be Greenhouse gases. and allows the use of alternative fuels such as corn oil, low-grade fuels, and even used motor oil. Bubble combustion is analogous to the inverse of spray combustion: the difference between bubble and spray combustion is that spray combustion is spraying a liquid in to a gas to form droplets, whereas bubble combustion involves injecting a gas into a liquid to form gaseous bubbles. In bubble combustion, the process for the ignition of the bubbles takes place on a time scale of less than a nanosecond and begins with acoustic waves perturbing each bubble. This perturbation causes the local pressure to drop below the vapor pressure of the liquid thus producing cavitation in which the bubble diameter grows, and upon reversal of the oscillating pressure field, the bubble then collapses rapidly with the aid of the high surface tension forces acting on the wall of the bubble. The rapid and violent collapse causes the temperatures inside the bubbles to soar as a result of adiabatic heating. As the temperatures rise, the gaseous contents of the bubble ignite with the bubble itself serving as its own combustion chamber. After ignition, this is the time in the bubble s life cycle where power is generated, and CO2, and NOx among other species, are produced. However, the pollutants CO2 and NOx are absorbed into the surrounding liquid. The importance of bubble combustion is that it generates power using a simple and compact device. We conducted a parametric study using CAVCHEM

  13. NASA Microgravity Combustion Science Program

    NASA Technical Reports Server (NTRS)

    King, Merrill K.

    1997-01-01

    Combustion is a key element of many critical technologies used by contemporary society. For example, electric power production, home heating, surface and air transportation, space propulsion, and materials synthesis all utilize combustion as a source of energy. Yet, although combustion technology is vital to our standard of living, it poses great challenges to maintaining a habitable environment. For example, pollutants, atmospheric change and global warming, unwanted fires and explosions, and the incineration of hazardous wastes are major problem areas which would benefit from improved understanding of combustion. Effects of gravitational forces impede combustion studies more than most other areas of science since combustion involves production of high-temperature gases whose low density results in buoyant motion, vastly complicating the execution and interpretation of experiments. Effects of buoyancy are so ubiquitous that their enormous negative impact on the rational development of combustion science is generally not recognized. Buoyant motion also triggers the onset of turbulence, yielding complicating unsteady effects. Finally, gravity forces cause particles and drops to settle, inhibiting deconvoluted studies of heterogeneous flames important to furnace, incineration and power generation technologies. Thus, effects of buoyancy have seriously limited our capabilities to carry out 'clean' experiments needed for fundamental understanding of flame phenomena. Combustion scientists can use microgravity to simplify the study of many combustion processes, allowing fresh insights into important problems via a deeper understanding of elemental phenomena also found in Earth-based combustion processes and to additionally provide valuable information concerning how fires behave in microgravity and how fire safety on spacecraft can be enhanced.

  14. APTI Course 427, Combustion Evaluation. Student Manual.

    ERIC Educational Resources Information Center

    Beard, J. Taylor; And Others

    This student manual supplements a course designed to present fundamental and applied aspects of combustion technology which influence air pollutant emissions. Emphasis is placed on process control of combustion rather than on gas cleaning. The course is intended to provide engineers, regulatory and technical personnel, and others with familiarity…

  15. Method and system for controlled combustion engines

    DOEpatents

    Oppenheim, A. K.

    1990-01-01

    A system for controlling combustion in internal combustion engines of both the Diesel or Otto type, which relies on establishing fluid dynamic conditions and structures wherein fuel and air are entrained, mixed and caused to be ignited in the interior of a multiplicity of eddies, and where these structures are caused to sequentially fill the headspace of the cylinders.

  16. Spontaneous ignition characteristics of gaseous hydrocarbon-air mixtures

    NASA Technical Reports Server (NTRS)

    Freeman, G.; Lefebvre, A. H.

    1984-01-01

    Experiments are conducted to determine the spontaneous ignition delay times of gaseous propane, kerosine vapor, and n-heptane vapor in mixtures with air, and oxygen-enriched air, at atmospheric pressure. Over a range of equivalence ratios from 0.2 to 0.8 it is found that ignition delay times are sensibly independent of fuel concentration. However, the results indicate a strong dependence of delay times on oxygen concentration. The experimental data for kerosine and propane demonstrate very close agreement with the results obtained previously by Mullins and Lezberg respectively.

  17. Turbulent Combustion in SDF Explosions

    SciTech Connect

    Kuhl, A L; Bell, J B; Beckner, V E

    2009-11-12

    A heterogeneous continuum model is proposed to describe the dispersion and combustion of an aluminum particle cloud in an explosion. It combines the gas-dynamic conservation laws for the gas phase with a continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models. It incorporates a combustion model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the C-4 booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Numerical simulations of the explosion fields from 1.5-g Shock-Dispersed-Fuel (SDF) charge in a 6.6 liter calorimeter were used to validate the combustion model. Then the model was applied to 10-kg Al-SDF explosions in a an unconfined height-of-burst explosion. Computed pressure histories are compared with measured waveforms. Differences are caused by physical-chemical kinetic effects of particle combustion which induce ignition delays in the initial reactive blast wave and quenching of reactions at late times. Current simulations give initial insights into such modeling issues.

  18. Putting combustion optimization to work

    SciTech Connect

    Spring, N.

    2009-05-15

    New plants and plants that are retrofitting can benefit from combustion optimization. Boiler tuning and optimization can complement each other. The continuous emissions monitoring system CEMS, and tunable diode laser absorption spectroscopy TDLAS can be used for optimisation. NeuCO's CombustionOpt neural network software can determine optimal fuel and air set points. Babcock and Wilcox Power Generation Group Inc's Flame Doctor can be used in conjunction with other systems to diagnose and correct coal-fired burner performance. The four units of the Colstrip power plant in Colstrips, Montana were recently fitted with combustion optimization systems based on advanced model predictive multi variable controls (MPCs), ABB's Predict & Control tool. Unit 4 of Tampa Electric's Big Bend plant in Florida is fitted with Emerson's SmartProcess fuzzy neural model based combustion optimisation system. 1 photo.

  19. Combustion modeling in waste tanks

    SciTech Connect

    Mueller, C.; Unal, C.; Travis, J.R. |

    1997-08-01

    This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data.

  20. Theoretical nitric oxide production incidental to autoignition and combustion of several fuels homogeneously dispersed in air under some typical hypersonic flight conditions

    NASA Technical Reports Server (NTRS)

    Bahn, G. S.

    1974-01-01

    A reaction package of 100 chemical reactions and attendant reaction rate constants defined for the autoignition and combustion of four carbonaceous fuels, CH4, CH3OH, C2H6, and C2H5OH. Definition of the package was made primarily by means of comparison between trial calculations and experimental data for the autoignition of CH4. Autoignition and combustion of each of these four fuels was calculated under three sets of conditions realistic for hypersonic flight applications, for comparison to hydrogen fuel, particularly with respect to formation of nitric oxide. Results show that, for all of the fuels including hydrogen, if NO production is a significant problem, compromise must be made between approaching equilibrium heat release and approaching equilibrium NO concentration.

  1. Turbulent combustion

    SciTech Connect

    Talbot, L.; Cheng, R.K.

    1993-12-01

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  2. Compressed air energy storage system

    DOEpatents

    Ahrens, F.W.; Kartsounes, G.T.

    An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

  3. Furnace combustion zone temperature control method

    SciTech Connect

    McIntyre, G.C.; Lacombe, R.J.; Forbess, R.G.

    1991-05-28

    This patent describes a method for controlling temperature in a combustion zone in a furnace, independent of flue gas oxygen content. It comprises: supplying combustion air to the furnace for combustion of a fuel therein; providing a plurality of low volume gas flow entry ports to the combustion zone in the furnace with carrier gas continuously flowing through the ports into the combustion zone; selecting a set point value for the combustion zone temperature which, upon the temperature exceeding the set point value, commences generation of a fine water mist external the combustion zone by mist generating means within the carrier gas, the mist flowing into the combustion zone with the carrier gas and reducing temperature within the combustion zone by vaporization therein; and adding a proportionately greater amount of water mist to the carrier gas as the temperature of the combustion zone deviates above the set point value, the amount of water mist added limited by the capacity of the mist generating means, and ceasing the water mist generation upon the combustion zone temperature falling to or below the set point value.

  4. STATIONARY SOURCE COMBUSTION: AN R/D UPDATE

    EPA Science Inventory

    The paper discusses EPA/IERL-RTP R&D, underway since 1967, to advance combustion technology and the abatement and control of nitrogen oxides (NOx) and other combustion-generated pollutants from major stationary combustion sources. The primary air pollutants under consideration in...

  5. INDUCED SECONDARY COMBUSTION IN WOODSTOVES

    EPA Science Inventory

    The paper provides information useful for woodstove designers concerned with reducing emissions. A dual-chamber woodstove was modified to induce secondary combustion by utilizing an ignition source and forced flow of secondary air. The ignition source was an electric glow plug in...

  6. Catalyzing the Combustion of Coal

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; Dokko, W.

    1982-01-01

    Reaction rate of coal in air can be increased by contacting or coating coal with compound such as calcium acetate. The enhanced reaction rate generates more heat, reducing furnace size. Increase in combustion rate is about 26 percent, and internal pollutants in powerplant are reduced.

  7. Space Station Freedom combustion research

    NASA Technical Reports Server (NTRS)

    Faeth, G. M.

    1992-01-01

    spread of liquids, drop combustion, and quenching of panicle-air flames. Unfortunately, the same features that make microgravity attractive for fundamental combustion experiments, introduce new fire and explosion hazards that have no counterpart on earth. For example, microgravity can cause broader flammability limits, novel regimes of flame spread, enhanced effects of flame radiation, slower fire detector response, and enhanced combustion upon injecting fire extinguishing agents, among others. On the other hand, spacecraft provide an opportunity to use 'fire-safe' atmospheres due to their controlled environment. Investigation of these problems is just beginning, with specific fire safety experiments supplementing the space based fundamental experiments listed earlier; thus, much remains to be done to develop an adequate technology base for fire and explosion safety considerations for spacecraft.

  8. Hydrogen combustion in tomorrow's energy technology

    NASA Astrophysics Data System (ADS)

    Peschka, W.

    The fundamental characteristics of hydrogen combustion and the current status of hydrogen energy applications technology are reviewed, with an emphasis on research being pursued at DFVLR. Topics addressed include reaction mechanisms and pollution, steady-combustion devices (catalytic heaters, H2/air combustors, H2/O2 rocket engines, H2-fueled jet engines, and gas and steam turbine processes), unsteady combustion (in internal-combustion engines with internal or external mixture formation), and feasibility studies of hydrogen-powered automobiles. Diagrams, drawings, graphs, and photographs are provided.

  9. Preparation and characterization of nano- and non-nanoscale Co₃O₄ spinels obtained from different methods and study of their performance in combustion of aromatics from polluted air-A comparison with Pt/γ-Al₂O₃ performance.

    PubMed

    Hosseini, Seyedali; Niaei, Aligholi; Salari, Dariush

    2012-01-01

    This article reports the development of oxidative precipitation (OP) method for synthesis of Co(3)O(4) as an environmental catalyst and comparison of its performance with that of obtained from conventional sol gel combustion (SG) method and industrial Pt/γ-Al(2)O(3) in remediation of toluene from air. Catalytic studies were carried out in a fixed bed reactor at 100-350°C under atmospheric pressure. Co(3)O(4) (OP) showed the highest activity in combustion of toluene. The half conversion temperature of toluene (T(50%)) was 160, 258, and 229°C on Co(3)O(4) (OP), Co(3)O(4) (SG) and Pt/γ-Al(2)O(3), respectively. The higher activity of Co(3)O(4) (OP) was ascribed to nanostructure and reducibility of catalytic sites at lower temperatures, approved by TPR results. The study confirmed that preparation method has a large influence on the chemical-physical properties and activity of the catalyst. The study indicated that oxidative precipitation method could be a promising method to synthesize environmental catalysts considering the simplicity and needless to calcine catalyst at higher temperatures. PMID:22755518

  10. Regenerative combustion device

    DOEpatents

    West, Phillip B.

    2004-03-16

    A regenerative combustion device having a combustion zone, and chemicals contained within the combustion zone, such as water, having a first equilibrium state, and a second combustible state. Means for transforming the chemicals from the first equilibrium state to the second combustible state, such as electrodes, are disposed within the chemicals. An igniter, such as a spark plug or similar device, is disposed within the combustion zone for igniting combustion of the chemicals in the second combustible state. The combustion products are contained within the combustion zone, and the chemicals are selected such that the combustion products naturally chemically revert into the chemicals in the first equilibrium state following combustion. The combustion device may thus be repeatedly reused, requiring only a brief wait after each ignition to allow the regeneration of combustible gasses within the head space.

  11. Advanced Combustion

    SciTech Connect

    Holcomb, Gordon R.

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  12. Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

    NASA Technical Reports Server (NTRS)

    Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

    2015-01-01

    Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

  13. Increasing reliability of gas-air systems of piston and combined internal combustion engines by improving thermal and mechanic flow characteristics

    NASA Astrophysics Data System (ADS)

    Brodov, Yu. M.; Grigor'ev, N. I.; Zhilkin, B. P.; Plotnikov, L. V.; Shestakov, D. S.

    2015-12-01

    Results of experimental study of thermal and mechanical characteristics of gas exchange flow in piston and combined engines are presented. Ways for improving intake and exhaust processes to increase reliability of gas-air engine systems are proposed.

  14. Droplet Combustion Experiment (DCE)

    NASA Technical Reports Server (NTRS)

    Haggard, John B., Jr.; Nayagan, Vedha; Dryer, Frederick L.; Williams, Forman A.

    1998-01-01

    The first space-based experiments were performed on the combustion of free, individual liquid fuel droplets in oxidizing atmospheres. The fuel was heptane, with initial droplet diameters ranging about from 1 mm to 4 mm. The atmospheres were mixtures of helium and oxygen, at pressures of 1.00, 0.50 and 0.25 bar, with oxygen mole fractions between 20% and 40%, as well as normal Spacelab cabin air. The temperatures of the atmospheres and of the initial liquid fuel were nominally 300 K. A total of 44 droplets were burned successfully on the two flights, 8 on the shortened STS-83 mission and 36 on STS-94. The results spanned the full range of heptane droplet combustion behavior, from radiative flame extinction at larger droplet diameters in the more dilute atmospheres to diffusive extinction in the less dilute atmospheres, with the droplet disappearing prior to flame extinction at the highest oxygen concentrations. Quasisteady histories of droplet diameters were observed along with unsteady histories of flame diameters. New and detailed information was obtained on burning rates, flame characteristics and soot behavior. The results have motivated new computational and theoretical investigations of droplet combustion, improving knowledge of the chemical kinetics, fluid mechanics and heat and mass transfer processes involved in burning liquid fuels.

  15. Assessment of Literature Related to Combustion Appliance Venting Systems

    SciTech Connect

    Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

    2015-02-01

    In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

  16. CFD simulation of pulse combustion's performance

    NASA Astrophysics Data System (ADS)

    Rahmatika, Annie Mufyda; Widiyastuti, W.; Winardi, Sugeng; Nurtono, Tantular; Machmudah, Siti; Kusdianto, Joni, I. Made

    2016-02-01

    This study aims to show changes in the performance of combustion using pulse combustion at specified intervals using simulation. Simulations is performed using Computational Fluid Dynamics analysis (CFD) software Ansys Fluent 15.0. Analysis used 2D illustration axisymmetric with k-ɛ turbulence models. Propane was selected as fuel at a flow rate of 15 L/min. Air with flow rate of 375 L/min is used as oxidizer. To investigate the advantages of using pulse combustion, the simulated pulse combustion is compared to normal combustion without a pulse. This is done by displaying descriptions of the phenomenon, mechanisms and results output gas combustor. From the analysis of simulation results showed that in 1 minute burning time, burning fuel without requiring pulse as much as 15 L while the pulse combustion requires half of the fuel which is 12.5 L. However, the higher average of temperature was generated by pulse combustion and the amounts of unburned fuel that comes out of the combustor less than without the use of pulse combustion. So, it can be concluded that the pulse combustion is more efficient than combustion without a pulse.

  17. APPLICATION OF COMBUSTION MODIFICATIONS TO INDUSTRIAL COMBUSTION EQUIPMENT (DATA SUPPLEMENT A)

    EPA Science Inventory

    The supplement provides raw data from a study of the effects of combustion modifications on air pollutant emissions from a variety of industrial combustion equipment. Tested were 22 units, including refinery process heaters; clay and cement kilns; steel and aluminum furnaces; boi...

  18. APPLICATION OF COMBUSTION MODIFICATIONS TO INDUSTRIAL COMBUSTION EQUIPMENT (DATA SUPPLEMENT B)

    EPA Science Inventory

    The supplement provides raw data from a study of the effects of combustion modifications on air pollutant emissions from a variety of industrial combustion equipment. Tested were 22 units, including refinery process heaters; clay and cement kilns; steel and aluminum furnaces; boi...

  19. Combustion in porous media

    SciTech Connect

    Dillon, J.

    1999-09-01

    A 2.8-liter tube-shaped combustion vessel was constructed to study flame propagation and quenching in porous media. For this experiment, hydrogen-air flames propagating horizontally into abed of 6 mm diameter glass beads were studied. Measurements of pressure and temperature along the length of the tube were used to observe flame propagation of quenching. The critical hydrogen concentration for Hz-air mixtures was found to be 11.5%, corresponding to a critical Peclet number of Pe* = 37. This value is substantially less than the value of Pe* = 65 quoted in the literature, for example Babkin et al. (1991). It is hypothesized that buoyancy and a dependence of Pe on the Lewis number account for the discrepancy between these two results.

  20. Production of particulate matter from the combustion of wood pellets

    NASA Astrophysics Data System (ADS)

    Papučík, Štefan; Jandačka, Jozef; Chabadová, Jana; Pialát, Peter

    2015-05-01

    For production of particulate matters affect more aspects. One of the biggest affect is combustion air volume and iťs deviding on primary and secondary part. In this article is described experimental device, on which was investigated affect of combustion air volume on production particulate matters, measuring method, measured and analysed achieved results.

  1. MONITORING STRATEGIES FOR FLUIDIZED BED COMBUSTION COAL PLANTS

    EPA Science Inventory

    Air and water monitoring strategies for commercial-size Fluidized Bed Combustion (FBC) coal plants are presented. This is one of five reports developing air and water monitoring strategies for advanced coal combustion (FBC), coal conversion (coal gasification and liquefaction), a...

  2. Stationary Engineers Apprenticeship. Related Training Modules. 16.1-16.5 Combustion.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This learning module, one in a series of 20 related training modules for apprentice stationary engineers, deals with combustion. Addressed in the individual instructional packages included in the module are the following topics: the combustion process, types of fuel, air and flue gases, heat transfer during combustion, and wood combustion. Each…

  3. Dickinson Pure Air Combustion ERIP technical progress report number 4 [for the reporting period 7/98 through 9/98

    SciTech Connect

    Klosky, M.

    1998-09-15

    Research was focused on work done to date and melding with current market conditions and demand. The overall objective of this program is to demonstrate the feasibility of EnerTech`s combustion technology to produce clean energy efficiently and cost effectively from coal and/or other char slurry fuels. From the data generated in this project, EnerTech will be able to conduct preliminary engineering design work for a process development unit. The design work included simulations that optimize process cycle efficiency, and includes analysis of process temperature, pressures, and mass/energy flows. The overall goal is to conduct the research necessary to launch a commercial process. Market surveys indicated that stand-alone systems would not find a near-term market; therefore, the company is concentrating on a configuration that includes a process that first generates a slurry char product.

  4. E-Alerts: Combustion, engines, and propellants (reciprocation and rotating combustion engines). E-mail newsletter

    SciTech Connect

    1999-04-01

    Design, performance, and testing of reciprocating and rotating engines of various configurations for all types of propulsion. Includes internal and external combustion engines; engine exhaust systems; engine air systems components; engine structures; stirling and diesel engines.

  5. Ash characterization in laboratory-scale oxy-coal combustor

    EPA Science Inventory

    Oxygen enriched coal (oxy-coal) combustion is a developing technology. During oxy-coal combustion, combustion air is separated and the coal is burned in a mixture of oxygen and recycled flue gas. The resulting effluent must be further processed before the C02 can be compressed, t...

  6. Oscillating combustion from a premix fuel nozzle

    SciTech Connect

    Richards, G.A.; Yip, M.J.

    1995-08-01

    Stringent emissions requirements for stationary gas turbines have produced new challenges in combustor design. In the past, very low NOx pollutant emissions have been achieved through various combustion modifications, such as steam or water injection, or post-combustion cleanup methods such as selective catalytic reduction (SCR). An emerging approach to NOx abatement is lean premix combustion. Lean premix combustion avoids the cost and operational problems associated with other NOx control methods. By premixing fuel and air at very low equivalence ratios, the high temperatures which produce NOx are avoided. The challenges of premix combustion include avoiding flashback, and ensuring adequate fuel/air premixing. In addition, the combustion must be stable. The combustor should not operate so close to extinction that a momentary upset will extinguish the flame (static stability), and the flame should not oscillate (dynamic stability). Oscillations are undesirable because the associated pressure fluctuations can shorten component lifetime. Unfortunately, experience has shown that premix fuel nozzles burning natural gas are susceptible to oscillations. Eliminating these oscillations can be a costly and time consuming part of new engine development. As part of the U.S. Department of Energy`s Advanced Turbine Systems Program, the Morgantown Energy Technology Center (METC) is investigating the issue of combustion oscillations produced by lean premix fuel nozzles. METC is evaluating various techniques to stabilize oscillating combustion in gas turbines. Tests results from a premix fuel nozzle using swirl stabilization and a pilot flame are reported here.

  7. Combustion Limits and Efficiency of Turbojet Engines

    NASA Technical Reports Server (NTRS)

    Barnett, H. C.; Jonash, E. R.

    1956-01-01

    Combustion must be maintained in the turbojet-engine combustor over a wide range of operating conditions resulting from variations in required engine thrust, flight altitude, and flight speed. Furthermore, combustion must be efficient in order to provide the maximum aircraft range. Thus, two major performance criteria of the turbojet-engine combustor are (1) operatable range, or combustion limits, and (2) combustion efficiency. Several fundamental requirements for efficient, high-speed combustion are evident from the discussions presented in chapters III to V. The fuel-air ratio and pressure in the burning zone must lie within specific limits of flammability (fig. 111-16(b)) in order to have the mixture ignite and burn satisfactorily. Increases in mixture temperature will favor the flammability characteristics (ch. III). A second requirement in maintaining a stable flame -is that low local flow velocities exist in the combustion zone (ch. VI). Finally, even with these requirements satisfied, a flame needs a certain minimum space in which to release a desired amount of heat, the necessary space increasing with a decrease in pressure (ref. 1). It is apparent, then, that combustor design and operation must provide for (1) proper control of vapor fuel-air ratios in the combustion zone at or near stoichiometric, (2) mixture pressures above the minimum flammability pressures, (3) low flow velocities in the combustion zone, and (4) adequate space for the flame.

  8. Uncontrolled combustion of shredded tires in a landfill -Part 2: Population exposure, public health response, and an air quality index for urban fires

    PubMed Central

    Singh, Ashish; Spak, Scott N.; Stone, Elizabeth A.; Downard, Jared; Bullard, Robert; Pooley, Mark; Kostle, Pamela A.; Mainprize, Matthew W.; Wichman, Michael D.; Peters, Thomas; Beardsley, Douglas; Stanier, Charles O.

    2015-01-01

    The Iowa City Landfill in eastern Iowa, United States, experienced a fire lasting 18 days in 2012, in which a drainage layer of over 1 million shredded tires burned, generating smoke that impacted the surrounding metropolitan area of 130,000 people. This emergency required air monitoring, risk assessment, dispersion modeling, and public notification. This paper quantifies the impact of the fire on local air quality and proposes a monitoring approach and an Air Quality Index (AQI) for use in future tire fires and other urban fires. Individual fire pollutants are ranked for acute and cancer relative risks using hazard ratios, with the highest acute hazard ratios attributed to SO2, particulate matter, and aldehydes. Using a dispersion model in conjunction with the new AQI, we estimate that smoke concentrations reached unhealthy outdoor levels for sensitive groups out to distances of 3.1 km and 18 km at 24-h and 1-h average times, respectively. Modeled and measured concentrations of PM2.5 from smoke and other compounds such as VOCs and benzo[a]pyrene are presented at a range of distances and averaging times, and the corresponding cancer risks are discussed. Through reflection on the air quality response to the event, consideration of cancer and acute risks, and comparison to other tire fires, we recommend that all landfills with shredded tire liners plan for hazmat fire emergencies. A companion paper presents emission factors and detailed smoke characterization. PMID:25624787

  9. Uncontrolled combustion of shredded tires in a landfill - Part 2: Population exposure, public health response, and an air quality index for urban fires

    NASA Astrophysics Data System (ADS)

    Singh, Ashish; Spak, Scott N.; Stone, Elizabeth A.; Downard, Jared; Bullard, Robert L.; Pooley, Mark; Kostle, Pamela A.; Mainprize, Matthew W.; Wichman, Michael D.; Peters, Thomas M.; Beardsley, Douglas; Stanier, Charles O.

    2015-03-01

    The Iowa City Landfill in eastern Iowa, United States, experienced a fire lasting 18 days in 2012, in which a drainage layer of over 1 million shredded tires burned, generating smoke that impacted the surrounding metropolitan area of 130,000 people. This emergency required air monitoring, risk assessment, dispersion modeling, and public notification. This paper quantifies the impact of the fire on local air quality and proposes a monitoring approach and an air quality index (AQI) for use in future tire fires and other urban fires. Individual fire pollutants are ranked for acute and cancer relative risks using hazard ratios, with the highest acute hazard ratios attributed to SO2, particulate matter, and aldehydes. Using a dispersion model in conjunction with the new AQI, we estimate that smoke concentrations reached unhealthy outdoor levels for sensitive groups out to distances of 3.1 km and 18 km at 24-h and 1-h average times, respectively. Modeled and measured concentrations of PM2.5 from smoke and other compounds such as VOCs and benzo[a]pyrene are presented at a range of distances and averaging times, and the corresponding cancer risks are discussed. Through reflection on the air quality response to the event, consideration of cancer and acute risks, and comparison to other tire fires, we recommend that all landfills with shredded tire liners plan for hazmat fire emergencies. A companion paper presents emission factors and detailed smoke characterization.

  10. The reduction of gas phase air toxics from combustion and incineration sources using the GE-Mitsui-BF activated coke process

    SciTech Connect

    Olson, D.G.; Tsuji, K.; Shiraishi, I.

    1998-07-01

    The dry desulfurization, denitrification and air toxics removal process using activated coke (AC) was originally researched and developed during the 1960's by Bergbau Forschung (BF), now called Deutsche Montan Technologies. Mitsui Mining Company (MMC) signed a licensing agreement with BF in 1982 to investigate, test and adapt the system to facilities in Japan. Japanese regulations are stricter than in the US toward SOx/NOx pollutants, as well as flyash emissions from the utility industry, oil refineries and other industries. This process is installed on four coal-fired boilers and Fluidized Catalytic Cracker (FCC) units. These plants were constructed by MMC in Japan and Uhde GmbH in Germany. General Electric Environmental Services, Inc. (GEESI) signed a license agreement in 1992 with MMC and Mitsui and Company, Ltd. Of Tokyo. Under this agreement, GEESI will market, design, fabricate and install the Mitsui-BF process for flue gas cleaning applications in North America. MMC also developed a technology to produce AC used in the dry DeSOx/DeNOx/Air Toxics removal process based on their own metallurgical coke manufacturing technology. This paper provides information on the details of MMC's AC used in the dry DeSOx/DeNOx/Air Toxics removal process and of the DeSOx/DeNOx/Air Toxics removal process itself.

  11. Primary zone air proportioner

    DOEpatents

    Cleary, Edward N. G.

    1982-10-12

    An air proportioner is provided for a liquid hydrocarbon fueled gas turbine of the type which is convertible to oil gas fuel and to coal gas fuel. The turbine includes a shell for enclosing the turbine, an air duct for venting air in said shell to a gasifier, and a fuel injector for injecting gasified fuel into the turbine. The air proportioner comprises a second air duct for venting air from the air duct for mixing with fuel from the gasifier. The air can be directly injected into the gas combustion basket along with the fuel from the injector or premixed with fuel from the gasifier prior to injection by the fuel injector.

  12. Air pollution from aircraft

    NASA Technical Reports Server (NTRS)

    Heywood, J. B.; Fay, J. A.; Chigier, N. A.

    1979-01-01

    A series of fundamental problems related to jet engine air pollution and combustion were examined. These include soot formation and oxidation, nitric oxide and carbon monoxide emissions mechanisms, pollutant dispension, flow and combustion characteristics of the NASA swirl can combustor, fuel atomization and fuel-air mixing processes, fuel spray drop velocity and size measurement, ignition and blowout. A summary of this work, and a bibliography of 41 theses and publications which describe this work, with abstracts, is included.

  13. Research on oxidation by air and tempering of Raney nickel electrocatalysts for the H2 anodes of alkali combustion materials cells. Thesis - Braunschweig Technische Univ., 1982

    NASA Technical Reports Server (NTRS)

    Selbach, H. J.

    1984-01-01

    The controlled oxidation in air of Raney nickel electrocatalysts was studied, with special attention paid to the quantitative analysis of nickel hydroxide. The content of the latter was determined through X-ray studies, thermogravimetric measurements, and spectral photometric examinations. The dependence of the content on the drying of activated catalyst is determined. The influence of nickel hydroxide on the electrochemical parameters of the catalyst, such as diffusion polarization, is studied, including a measurement of the exchange current density using the potential drop method. Conservation by oxidation in air with ancillary stabilization of the oxide in an H2 flow at 300 C is explored, including reduction by H2, the influence of tempering time, and structural studies on conserved and stabilized catalyst, long term research on the catalyst, including the influence of aging on the reduced catalyst, and the results of impedance measurements are presented.

  14. Polycyclic aromatic hydrocarbon exposure in household air pollution from solid fuel combustion among the female population of Xuanwei and Fuyuan counties, China.

    PubMed

    Downward, George S; Hu, Wei; Rothman, Nat; Reiss, Boris; Wu, Guoping; Wei, Fusheng; Chapman, Robert S; Portengen, Lutzen; Qing, Lan; Vermeulen, Roel

    2014-12-16

    Exposure to polycyclic aromatic hydrocarbons (PAHs) from burning "smoky" (bituminous) coal has been implicated as a cause of the high lung cancer incidence in the counties of Xuanwei and Fuyuan, China. Little is known about variations in PAH exposure from throughout the region nor how fuel source and stove design affects exposure. Indoor and personal PAH exposure resulting from solid fuel combustion in Xuanwei and Fuyuan was investigated using repeated 24 h particle bound and gas-phase PAH measurements, which were collected from 163 female residents of Xuanwei and Fuyuan. 549 particle bound (283 indoor and 266 personal) and 193 gas phase (all personal) PAH measurements were collected. Mixed effect models indicated that PAH exposure was up to 6 times higher when burning smoky coal than smokeless coal and varied by up to a factor of 3 between different smoky coal geographic sources. PAH measurements from unventilated firepits were up to 5 times that of ventilated stoves. Exposure also varied between different room sizes and season of measurement. These findings indicate that PAH exposure is modulated by a variety of factors, including fuel type, coal source, and stove design. These findings may provide valuable insight into potential causes of lung cancer in the area. PMID:25393345

  15. Polycyclic Aromatic Hydrocarbon Exposure in Household Air Pollution from Solid Fuel Combustion among the Female Population of Xuanwei and Fuyuan Counties, China

    PubMed Central

    2015-01-01

    Exposure to polycyclic aromatic hydrocarbons (PAHs) from burning “smoky” (bituminous) coal has been implicated as a cause of the high lung cancer incidence in the counties of Xuanwei and Fuyuan, China. Little is known about variations in PAH exposure from throughout the region nor how fuel source and stove design affects exposure. Indoor and personal PAH exposure resulting from solid fuel combustion in Xuanwei and Fuyuan was investigated using repeated 24 h particle bound and gas-phase PAH measurements, which were collected from 163 female residents of Xuanwei and Fuyuan. 549 particle bound (283 indoor and 266 personal) and 193 gas phase (all personal) PAH measurements were collected. Mixed effect models indicated that PAH exposure was up to 6 times higher when burning smoky coal than smokeless coal and varied by up to a factor of 3 between different smoky coal geographic sources. PAH measurements from unventilated firepits were up to 5 times that of ventilated stoves. Exposure also varied between different room sizes and season of measurement. These findings indicate that PAH exposure is modulated by a variety of factors, including fuel type, coal source, and stove design. These findings may provide valuable insight into potential causes of lung cancer in the area. PMID:25393345

  16. Method and device for optimizing the air-fuel mixture burn rate of internal combustion engines during low speed, light and heavy load operating conditions

    SciTech Connect

    Burandt, C.O.

    1990-10-09

    This patent describes a method for optimizing low speed light load and low speed heavy load operating conditions in an internal combustion engine. The engine has a camshaft, a crankshaft, at least one intake valve and at least one piston, and is capable of providing for small valve events, and the engine providing for earlier than normal intake valve closings the method comprises: sensing the load demand on the engine, regulating the phasing of the operation of the camshaft of the engine with the operation of the crankshaft of the engine in response to the sensed load demand by advancing the operation of camshaft relative to the operation of the crankshaft when a heavy load demand is sensed and by retarding the operation of the camshaft relative to the operation of the crankshaft when alight load demand is sensed, and sensing detonation in the engine and regulating the phasing operation of the camshaft relative to the operation of the crankshaft by advancing the operation of the camshaft relative to the crankshaft when detonation is sensed.

  17. Air pollution and children: neural and tight junction antibodies and combustion metals, the role of barrier breakdown and brain immunity in neurodegeneration.

    PubMed

    Calderón-Garcidueñas, Lilian; Vojdani, Aristo; Blaurock-Busch, Eleonore; Busch, Yvette; Friedle, Albrecht; Franco-Lira, Maricela; Sarathi-Mukherjee, Partha; Martínez-Aguirre, Xavier; Park, Su-Bin; Torres-Jardón, Ricardo; D'Angiulli, Amedeo

    2015-01-01

    Millions of children are exposed to concentrations of air pollutants, including fine particulate matter (PM2.5), above safety standards. In the Mexico City Metropolitan Area (MCMA) megacity, children show an early brain imbalance in oxidative stress, inflammation, innate and adaptive immune response-associated genes, and blood-brain barrier breakdown. We investigated serum and cerebrospinal fluid (CSF) antibodies to neural and tight junction proteins and environmental pollutants in 139 children ages 11.91 ± 4.2 y with high versus low air pollution exposures. We also measured metals in serum and CSF. MCMA children showed significantly higher serum actin IgG, occludin/zonulin 1 IgA, IgG, myelin oligodendrocyte glycoprotein IgG and IgM (p < 0.01), myelin basic protein IgA and IgG, S-100 IgG and IgM, and cerebellar IgG (p < 0.001). Serum IgG antibodies to formaldehyde, benzene, and bisphenol A, and concentrations of Ni and Cd were significantly higher in exposed children (p < 0.001). CSF MBP antibodies and nickel concentrations were higher in MCMA children (p = 0.03). Air pollution exposure damages epithelial and endothelial barriers and is a robust trigger of tight junction and neural antibodies. Cryptic 'self' tight junction antigens can trigger an autoimmune response potentially contributing to the neuroinflammatory and Alzheimer and Parkinson's pathology hallmarks present in megacity children. The major factor determining the impact of neural antibodies is the integrity of the blood-brain barrier. Defining the air pollution linkage of the brain/immune system interactions and damage to physical and immunological barriers with short and long term neural detrimental effects to children's brains ought to be of pressing importance for public health. PMID:25147109

  18. A shift in emission time profiles of fossil fuel combustion due to energy transitions impacts source receptor matrices for air quality.

    PubMed

    Hendriks, Carlijn; Kuenen, Jeroen; Kranenburg, Richard; Scholz, Yvonne; Schaap, Martijn

    2015-03-01

    Effective air pollution and short-lived climate forcer mitigation strategies can only be designed when the effect of emission reductions on pollutant concentrations and health and ecosystem impacts are quantified. Within integrated assessment modeling source-receptor relationships (SRRs) based on chemistry transport modeling are used to this end. Currently, these SRRs are made using invariant emission time profiles. The LOTOS-EUROS model equipped with a source attribution module was used to test this assumption for renewable energy scenarios. Renewable energy availability and thereby fossil fuel back up are strongly dependent on meteorological conditions. We have used the spatially and temporally explicit energy model REMix to derive time profiles for backup power generation. These time profiles were used in LOTOS-EUROS to investigate the effect of emission timing on air pollutant concentrations and SRRs. It is found that the effectiveness of emission reduction in the power sector is significantly lower when accounting for the shift in the way emissions are divided over the year and the correlation of emissions with synoptic situations. The source receptor relationships also changed significantly. This effect was found for both primary and secondary pollutants. Our results indicate that emission timing deserves explicit attention when assessing the impacts of system changes on air quality and climate forcing from short lived substances. PMID:25594282

  19. The reduction of gas phase air toxics from combustion and incineration sources using the GE-MITSUI-BE activated coke process

    SciTech Connect

    Olson, D.G.

    1995-12-31

    The dry desulfurization, denitrification and air toxics removal process using activated coke (AC) was originally researched and developed during the 1960s by Bergbau Forschung (BF), now called Deutsche Montan Technologies. Mitsui Mining Company (MMC) signed a licensing agreement with BF in 1982 to investigate, test and adapt the system to the facilities in Japan. Japanese regulations are stricter than in the U.S. toward SO{sub x}/NO{sub x} pollutants, as well as flyash emissions from the utility industry, oil refineries and other industries. This process is installed on flour coal-fired boilers and Fluidized Catalytic Cracker (FCC) units. These plants were constructed by MCC in Japan and Uhde GmbH in Germany. General Electric Environmental Systems, Inc. (GEESI) signed a license agreement in 1992 with MMC and Mitsui and Company, Ltd. of Tokyo. Under this agreement, GEESI will market, design, fabricate and install the Mitsui-BF press for flue gas cleaning applications in North America. MMC also developed a technology to produce AC used in the dry DeSO{sub x}/DeNO{sub x}/Air Toxics removal process based on their own metallurgical coke manufacturing technology. This paper provides information on the details of MMC`s AC used in the dry DeSO{sub x}/DeNO{sub x}/Air Toxics removal process.

  20. Measurement of air toxic emissions from a coal-fired boiler equipped with a tangentially-fired low NOx combustion system

    SciTech Connect

    Dismukes, E.B.; Clarkson, R.J.; Hardman, R.R.; Elia, G.G.

    1993-11-01

    This paper presents the results of measurements of chemical emissions from a coal-burning, tangentially-fired, utility boiler equipped with a hot-side electrostatic precipitator and a low NOx firing system. The tests were conducted in response to Title III of the 1990 Amendments to the Clean Air Act which lists 189 chemicals to be evaluated as {open_quotes}Air Toxics.{close_quotes} The project was jointly funded by the Electric Power Research Institute and the US Department of Energy under an existing Innovative Clean Coal Technology Cooperative Agreement managed by Southern Company Services. Field chemical emissions monitoring was conducted in two phases: a baseline {open_quotes}pre-low NOx burner{close_quotes} condition in September 1991 and in the LNCFS Level III low NOx firing condition in January 1992. In addition to stack emissions measurements of both organic and inorganic chemicals, plant material balance evaluations were performed to determine the efficiency of the hot-side ESP at controlling emissions of air toxics and to determine the fate of the target chemicals in various plant process streams.

  1. Combustion chemistry

    SciTech Connect

    Brown, N.J.

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  2. JANNAF 37th Combustion Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Fry, Ronald S. (Editor); Gannaway, Mary T. (Editor)

    2000-01-01

    This volume, the first of two volumes is a compilation of 59 unclassified/unlimited-distribution technical papers presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 37th Combustion Subcommittee (CS) meeting held jointly with the 25th Airbreathing Propulsion Subcommittee (APS), 19th Propulsion Systems Hazards Subcommittee (PSHS), and 1st Modeling and Simulation Subcommittee (MSS) meetings. The meeting was held 13-17 November 2000 at the Naval Postgraduate School and Hyatt Regency Hotel, Monterey, California. Topics covered at the CS meeting include: a keynote address on the Future Combat Systems, and review of a new JANNAF Modeling and Simulation Subcommittee, and technical papers on gun propellant burning rate, gun tube erosion, advanced gun propulsion concepts, ETC guns, novel gun propellants; liquid, hybrid and novel propellant combustion; solid propellant combustion kinetics, GAP, ADN and RDX combustion, sandwich combustion, metal combustion, combustion instability, and motor combustion instability.

  3. Solid waste combustion for alpha waste incineration

    SciTech Connect

    Orloff, D.I.

    1981-02-01

    Radioactive waste incinerator development at the Savannah River Laboratory has been augmented by fundamental combustion studies at the University of South Carolina. The objective was to measure and model pyrolysis and combustion rates of typical Savannah River Plant waste materials as a function of incinerator operating conditions. The analytical models developed in this work have been incorporated into a waste burning transient code. The code predicts maximum air requirement and heat energy release as a function of waste type, package size, combustion chamber size, and temperature. Historically, relationships have been determined by direct experiments that did not allow an engineering basis for predicting combustion rates in untested incinerators. The computed combustion rates and burning times agree with measured values in the Savannah River Laboratory pilot (1 lb/hr) and full-scale (12 lb/hr) alpha incinerators for a wide variety of typical waste materials.

  4. Some characteristics of fine beryllium particle combustion

    NASA Astrophysics Data System (ADS)

    Davydov, D. A.; Kholopova, O. V.; Kolbasov, B. N.

    2007-08-01

    Beryllium dust will be produced under plasma interaction with beryllium armor of the first wall in ITER. Exothermal reaction of this dust with water steam or air, which can leak into the reactor vacuum chamber in some accidents, gives concern in respect to reactor safety. Results of studies devoted to combustion of fine beryllium particles are reviewed in the paper. A chemically active medium and elevated temperature are prerequisite to the combustion of beryllium particles. Their ignition is hampered by oxide films, which form a diffusion barrier on the particle surface as a result of pre-flame oxidation. The temperature to initiate combustion of particles depends on flame temperature, particle size, composition of combustible mixture, heating rate and other factors. In mixtures enriched with combustible, the flame temperature necessary to ignite individual particles approaches the beryllium boiling temperature.

  5. Effect of atmospheric stability on the impact of domestic wood combustion to air quality of a small urban township in winter

    NASA Astrophysics Data System (ADS)

    Grange, S. K.; Salmond, J. A.; Trompetter, W. J.; Davy, P. K.; Ancelet, T.

    2013-05-01

    In the winter of 2011, a field campaign was undertaken in the small township of Nelson, New Zealand to measure the vertical and horizontal distribution of concentrations of airborne particulate matter. The aim of this campaign was to improve our understanding of the causal factors which result in periods of very high concentrations of particulate pollution in small townships during winter where emissions are dominated by the combustion of wood for domestic heating. The results showed that mean hourly surface concentrations of particulates throughout the airshed were characterized by a distinctive diurnal cycle, with two peaks in concentration (one in the late evening and then, unusually, a second mid-morning). Although the timing and magnitude of hourly peak concentrations was variable throughout the valley, there was no evidence to suggest that regional or topographic flows played a significant role in the build-up of pollutants at any given location. Analysis of vertical profiles of black carbon showed that high concentrations of particulates were confined to the lowest 50 m of the boundary layer. Concentrations decreased with increasing height within this polluted surface layer. The atmosphere was very stable during the evening period. After midnight, a period of increased mixing was consistently identified throughout the lowest 100 m of the boundary layer and associated with the sudden cleansing of the surface and lower layers of the boundary layer. Throughout the observational period there was no evidence for the storage of pollutants aloft. Thus the vertical mixing of pollutants to the surface could not account for increased pollutant concentrations during the morning period. However, at this time the boundary layer remained stable and concentrations of black carbon were mixed through a very shallow layer. This suggests that despite lower domestic heating emissions in the morning, the reduced mixing volume is a likely cause of the observed marked peak in

  6. Combustion mode switching with a turbocharged/supercharged engine

    SciTech Connect

    Mond, Alan; Jiang, Li

    2015-09-22

    A method for switching between low- and high-dilution combustion modes in an internal combustion engine having an intake passage with an exhaust-driven turbocharger, a crankshaft-driven positive displacement supercharger downstream of the turbocharger and having variable boost controllable with a supercharger bypass valve, and a throttle valve downstream of the supercharger. The current combustion mode and mass air flow are determined. A switch to the target combustion mode is commanded when an operating condition falls within a range of predetermined operating conditions. A target mass air flow to achieve a target air-fuel ratio corresponding to the current operating condition and the target combustion mode is determined. The degree of opening of the supercharger bypass valve and the throttle valve are controlled to achieve the target mass air flow. The amount of residual exhaust gas is manipulated.

  7. JANNAF 36th Combustion Subcommittee Meeting. Volume 2

    NASA Technical Reports Server (NTRS)

    Fry, Ronald S. (Editor); Gannaway, Mary T. (Editor)

    1999-01-01

    Volume 11, the second of three volumes is a compilation of 33 unclassified/unlimited-distribution technical papers presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 36th Combustion Subcommittee held jointly with the 24 Airbreathing Propulsion Subcommittee and 18th Propulsion Systems Hazards Subcommittee. The meeting was held on 18-21 October 1999 at NASA Kennedy Space Center and The DoubleTree Oceanfront Hotel, Cocoa Beach, Florida. Topics covered include gun solid propellant ignition and combustion, Electrothermal Chemical (ETC) propulsion phenomena, liquid propellant gun combustion and barrel erosion, gas phase propellant combustion, kinetic and decomposition phenomena and liquid and hybrid propellant combustion behavior.

  8. Test Would Quantify Combustion Oxygen From Different Sources

    NASA Technical Reports Server (NTRS)

    Tapphorn, Ralph M.

    1993-01-01

    Proposed isotope-enrichment scheme enables determination of contributions of dual sources of oxygen for combustion. Liquid oxygen or other artificial stream enriched with O(18) to about 1 percent by weight. Combustion products analyzed by mass spectrometer to measure relative abundances of H2O(18) and H2O(16). From relative abundances of water products measured, one computes relative contribution of oxygen extracted from stream compared to other source of oxygen in combustion process. Used to determine contributions of natural oxygen in air and liquid oxygen supplied in separate stream mixed with air or sent directly into combustion chamber.

  9. Homogeneous catalysts in hypersonic combustion

    SciTech Connect

    Harradine, D.M.; Lyman, J.L.; Oldenborg, R.C.; Pack, R.T.; Schott, G.L.

    1989-01-01

    Density and residence time both become unfavorably small for efficient combustion of hydrogen fuel in ramjet propulsion in air at high altitude and hypersonic speed. Raising the density and increasing the transit time of the air through the engine necessitates stronger contraction of the air flow area. This enhances the kinetic and thermodynamic tendency of H/sub 2/O to form completely, accompanied only by N/sub 2/ and any excess H/sub 2/(or O/sub 2/). The by-products to be avoided are the energetically expensive fragment species H and/or O atoms and OH radicals, and residual (2H/sub 2/ plus O/sub 2/). However, excessive area contraction raises air temperature and consequent combustion-product temperature by adiabatic compression. This counteracts and ultimately overwhelms the thermodynamic benefit by which higher density favors the triatomic product, H/sub 2/O, over its monatomic and diatomic alternatives. For static pressures in the neighborhood of 1 atm, static temperature must be kept or brought below ca. 2400 K for acceptable stability of H/sub 2/O. Another measure, whose requisite chemistry we address here, is to extract propulsive work from the combustion products early in the expansion. The objective is to lower the static temperature of the combustion stream enough for H/sub 2/O to become adequately stable before the exhaust flow is massively expanded and its composition ''frozen.'' We proceed to address this mechanism and its kinetics, and then examine prospects for enhancing its rate by homogeneous catalysts. 9 refs.

  10. Waste combustion in boilers and industrial furnaces

    SciTech Connect

    1996-12-31

    This publication contains technical papers published as they were presented at a recent specialty conference sponsored by the Air & Waste Management Association, titled Waste Combustion in Boilers and Industrial Furnaces, held March 26-27, 1996, in Kansas City, Missouri. Papers touch on compilance concerns for air pollution, air monitoring methodologies, risk assessment, and problems related to public anxiety. Separate abstracts have been indexed into the database from this proceedings.

  11. Combustion Byproducts Recycling Consortium

    SciTech Connect

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Each year, over 100 million tons of solid byproducts are produced by coal-burning electric utilities in the United States. Annual production of flue gas desulfurization (FGD) byproducts continues to increase as the result of more stringent sulfur emission restrictions. In addition, stricter limits on NOx emissions mandated by the 1990 Clean Air Act have resulted in utility burner/boiler modifications that frequently yield higher carbon concentrations in fly ash, which restricts the use of the ash as a cement replacement. Controlling ammonia in ash is also of concern. If newer, 'clean coal' combustion and gasification technologies are adopted, their byproducts may also present a management challenge. The objective of the Combustion Byproducts Recycling Consortium (CBRC) is to develop and demonstrate technologies to address issues related to the recycling of byproducts associated with coal combustion processes. A goal of CBRC is that these technologies, by the year 2010, will lead to an overall ash utilization rate from the current 34% to 50% by such measures as increasing the current rate of FGD byproduct use and increasing in the number of uses considered 'allowable' under state regulations. Another issue of interest to the CBRC would be to examine the environmental impact of both byproduct utilization and disposal. No byproduct utilization technology is likely to be adopted by industry unless it is more cost-effective than landfilling. Therefore, it is extremely important that the utility industry provide guidance to the R&D program. Government agencies and private-sector organizations that may be able to utilize these materials in the conduct of their missions should also provide input. The CBRC will serve as an effective vehicle for acquiring and maintaining guidance from these diverse organizations so that the proper balance in the R&D program is achieved.

  12. Combustion Byproducts Recycling Consortium

    SciTech Connect

    Ziemkiewicz, Paul; Vandivort, Tamara; Pflughoeft-Hassett, Debra; Chugh, Y Paul; Hower, James

    2008-08-31

    Each year, over 100 million tons of solid byproducts are produced by coal-burning electric utilities in the United States. Annual production of flue gas desulfurization (FGD) byproducts continues to increase as the result of more stringent sulfur emission restrictions. In addition, stricter limits on NOx emissions mandated by the 1990 Clean Air Act have resulted in utility burner/boiler modifications that frequently yield higher carbon concentrations in fly ash, which restricts the use of the ash as a cement replacement. Controlling ammonia in ash is also of concern. If newer, “clean coal” combustion and gasification technologies are adopted, their byproducts may also present a management challenge. The objective of the Combustion Byproducts Recycling Consortium (CBRC) is to develop and demonstrate technologies to address issues related to the recycling of byproducts associated with coal combustion processes. A goal of CBRC is that these technologies, by the year 2010, will lead to an overall ash utilization rate from the current 34% to 50% by such measures as increasing the current rate of FGD byproduct use and increasing in the number of uses considered “allowable” under state regulations. Another issue of interest to the CBRC would be to examine the environmental impact of both byproduct utilization and disposal. No byproduct utilization technology is likely to be adopted by industry unless it is more cost-effective than landfilling. Therefore, it is extremely important that the utility industry provide guidance to the R&D program. Government agencies and privatesector organizations that may be able to utilize these materials in the conduct of their missions should also provide input. The CBRC will serve as an effective vehicle for acquiring and maintaining guidance from these diverse organizations so that the proper balance in the R&D program is achieved.

  13. Internal combustion engine and method for control

    SciTech Connect

    Brennan, Daniel G

    2013-05-21

    In one exemplary embodiment of the invention an internal combustion engine includes a piston disposed in a cylinder, a valve configured to control flow of air into the cylinder and an actuator coupled to the valve to control a position of the valve. The internal combustion engine also includes a controller coupled to the actuator, wherein the controller is configured to close the valve when an uncontrolled condition for the internal engine is determined.

  14. Pulsed jet combustion generator for premixed charge engines

    DOEpatents

    Oppenheim, A. K.; Stewart, H. E.; Hom, K.

    1990-01-01

    A method and device for generating pulsed jets which will form plumes comprising eddie structures, which will entrain a fuel/air mixture from the head space of an internal combustion engine, and mixing this fuel/air mixture with a pre-ignited fuel/air mixture of the plumes thereby causing combustion of the reactants to occur within the interior of the eddie structures.

  15. Health effects of air pollution due to coal combustion in the Chestnut Ridge region of Pennsylvania: cross-section survey of children

    SciTech Connect

    Schenker, M.B.; Vedal, S.; Batterman, S.; Samet, J.; Speizer, F.E.

    1986-03-01

    A cross-sectional study of 4071 children aged 6-11 yr of age from a rural region of Western Pennsylvania was conducted in spring of 1979. Standardized children's questionnaires were distributed to the parents and returned by the children to school, where spirometry was performed. The region was divided into low-, moderate-, and high-pollution areas on the basis of the 1974-1978, 3-hr, 24-hr, and annual averages for sulfur dioxide (SO/sub 2/). Seventeen monitoring stations in the region and a triangulation procedure were used to estimate centroid levels in each geographic residence area. After adjusting the respiratory symptom response outcomes and the pulmonary function levels for known predictors, no significant association was noted for level of SO/sub 2/. However, the highest exposure categories were only slightly above the present annual and 24-hr National Air Quality Standards for SO/sub 2/. We conclude that at levels of exposure to which these children were exposed, only by study of potentially sensitive subsets or measures of acute response would it be possible to detect respiratory outcomes associated with ambient air pollution.

  16. Effect of Oxyfuel Combustion on Superheater Corrosion

    SciTech Connect

    Covino, B.S., Jr.; Matthes, S.A.; Bullard, S.J.

    2008-03-16

    Combustion of coal in an oxygen environment (as opposed to air) will facilitate the sequestering of carbon dioxide by minimizing the amount of nitrogen in the exit gas stream. The presence of higher levels of certain gases associated with oxyfuel combustion (eg, CO2, SO2, and H2O) may impact the corrosion of waterwalls, superheaters, headers, reheaters, and other boiler components. Research is being conducted on bare and ash-embedded boiler tube materials in simulated oxyfuel- combustion and air-combustion environments at a superheater temperature of 675°C. Alloys were exposed at temperature to two different gaseous environments. Preliminary results show: (1) an increase in corrosion rate of bare K02707, K11547, K21590, K91560, K92460, S30409, S34700, and N06617 exposed to the oxyfuel combustion environment when compared to the air combustion environment; (2) an increase in corrosion rate of alloys K21590, K92460, S34700, and N06617, when embedded in ash in comparison to bare exposure; and (3) no effect of gaseous environment on alloy corrosion rate when embedded in ash.

  17. Carburetor for internal combustion engines

    DOEpatents

    Csonka, John J.; Csonka, Albert B.

    1978-01-01

    A carburetor for internal combustion engines having a housing including a generally discoidal wall and a hub extending axially from the central portion thereof, an air valve having a relatively flat radially extending surface directed toward and concentric with said discoidal wall and with a central conoidal portion having its apex directed toward the interior of said hub portion. The housing wall and the radially extending surface of the valve define an air passage converging radially inwardly to form an annular valving construction and thence diverge into the interior of said hub. The hub includes an annular fuel passage terminating at its upper end in a circumferential series of micro-passages for directing liquid fuel uniformly distributed into said air passage substantially at said valving constriction at right angles to the direction of air flow. The air valve is adjustable axially toward and away from the discoidal wall of the carburetor housing to regulate the volume of air drawn into the engine with which said carburetor is associated. Fuel is delivered under pressure to the fuel metering valve and from there through said micro-passages and controlled cams simultaneously regulate the axial adjustment of said air valve and the rate of delivery of fuel through said micro-passages according to a predetermined ratio pattern. A third jointly controlled cam simultaneously regulates the ignition timing in accordance with various air and fuel supply settings. The air valve, fuel supply and ignition timing settings are all independent of the existing degree of engine vacuum.

  18. Fluids and Combustion Facility: Combustion Integrated Rack Modal Model Correlation

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Suarez, Vicente J.; Sullivan, Timothy L.; Otten, Kim D.; Akers, James C.

    2005-01-01

    The Fluids and Combustion Facility (FCF) is a modular, multi-user, two-rack facility dedicated to combustion and fluids science in the US Laboratory Destiny on the International Space Station. FCF is a permanent facility that is capable of accommodating up to ten combustion and fluid science investigations per year. FCF research in combustion and fluid science supports NASA's Exploration of Space Initiative for on-orbit fire suppression, fire safety, and space system fluids management. The Combustion Integrated Rack (CIR) is one of two racks in the FCF. The CIR major structural elements include the International Standard Payload Rack (ISPR), Experiment Assembly (optics bench and combustion chamber), Air Thermal Control Unit (ATCU), Rack Door, and Lower Structure Assembly (Input/Output Processor and Electrical Power Control Unit). The load path through the rack structure is outlined. The CIR modal survey was conducted to validate the load path predicted by the CIR finite element model (FEM). The modal survey is done by experimentally measuring the CIR frequencies and mode shapes. The CIR model was test correlated by updating the model to represent the test mode shapes. The correlated CIR model delivery is required by NASA JSC at Launch-10.5 months. The test correlated CIR flight FEM is analytically integrated into the Shuttle for a coupled loads analysis of the launch configuration. The analysis frequency range of interest is 0-50 Hz. A coupled loads analysis is the analytical integration of the Shuttle with its cargo element, the Mini Payload Logistics Module (MPLM), in the Shuttle cargo bay. For each Shuttle launch configuration, a verification coupled loads analysis is performed to determine the loads in the cargo bay as part of the structural certification process.

  19. Combustion system for hybrid solar fossil fuel receiver

    DOEpatents

    Mehos, Mark S.; Anselmo, Kenneth M.; Moreno, James B.; Andraka, Charles E.; Rawlinson, K. Scott; Corey, John; Bohn, Mark S.

    2004-05-25

    A combustion system for a hybrid solar receiver comprises a pre-mixer which combines air and fuel to form an air-fuel mixture. The mixture is introduced tangentially into a cooling jacket. A burner plenum is fluidically connected to the cooling jacket such that the burner plenum and the cooling jacket are arranged in thermal contact with one another. The air-fuel mixture flows through the cooling jacket cooling the burner plenum to reduce pre-ignition of the air-fuel mixture in the burner plenum. A combustion chamber is operatively associated with and open to the burner plenum to receive the air-fuel mixture from the burner plenum. An igniter is operatively positioned in the combustion chamber to combust the air-fuel mixture, releasing heat. A recuperator is operatively associated with the burner plenum and the combustion chamber and pre-heats the air-fuel mixture in the burner plenum with heat from the combustion chamber. A heat-exchanger is operatively associated and in thermal contact with the combustion chamber. The heat-exchanger provides heat for the hybrid solar receiver.

  20. Combustion Fundamentals Research

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Increased emphasis is placed on fundamental and generic research at Lewis Research Center with less systems development efforts. This is especially true in combustion research, where the study of combustion fundamentals has grown significantly in order to better address the perceived long term technical needs of the aerospace industry. The main thrusts for this combustion fundamentals program area are as follows: analytical models of combustion processes, model verification experiments, fundamental combustion experiments, and advanced numeric techniques.

  1. Coal combustion science

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

    1990-11-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 91 refs., 40 figs., 9 tabs.

  2. Combustion technologies

    SciTech Connect

    Barsin, J.A.

    1994-12-31

    The presentation will cover the highlights of sludge, providing information as to where it comes from, projection of how much more is expected, what is sludge, what can be done with them, and finally focus in one combustion technology that can be utilized and applied to recycle sludge. The author is with Gotaverken Energy Systems Inc. where for the past 100 years they have been involved in the recovery of chemicals in chemical pulp mills. One week ago, our name was changed to Kvaerner Pulping Inc. to better reflect our present make-up which is a combination of Kamyr AB (suppliers of proprietary highly engineered totally chlorine free chemical pulp manufacturing systems, including digesters, O{sub 2} delignification systems, and bleach plant systems) and Goetaverken. Sludges that we are concerned with derive from several sources within chemical pulp mills such as: such as primary clarifier sludges, secondary clarifier sludges, and most recently those sludges derived from post consumer paper and board recycle efforts including de-inking and those from the thermal mechanical pulping processes. These sludges have been classified as non-hazardous therefore, residue can be landfilled, but the volumes involved are growing at an alarming rate.

  3. Mechanisms and kinetics of granulated sewage sludge combustion.

    PubMed

    Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

    2015-12-01

    This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. PMID:26306758

  4. Counter-gradient transport in the combustion of a premixed CH{sub 4}/air annular jet by combined PIV/OH-LIF

    SciTech Connect

    Troiani, G.; Marrocco, M.; Giammartini, S.; Casciola, C.M.

    2009-03-15

    A combination of PIV/OH laser induced fluorescence technique is used to measure the conditional - burned and unburned - gas velocity in a turbulent premixed CH{sub 4}/air annular bluff-body stabilized burner. By changing the equivalence ratio from lean to almost stoichiometric, the energy budget of the recirculating region anchoring the flame is altered in such a way to increasingly lift the flame away from the jet exit. The overall turbulence intensity interacting with each flame is thus systematically varied in a significant range, allowing for a parametric study of its effect on turbulent scalar transport under well controlled conditions, always well within the flamelet regime. The component of the flux normal to the average front is found to reverse its direction, confirming the Bray number as a good indicator of gradient/counter-gradient behavior, once the actual incoming turbulence level felt locally by the flame is assumed as the proper control parameter. (author)

  5. Mercury and air toxic element impacts of coal combustion by-product disposal and utilization. Final report (for the period January 23, 2003 - December 31, 2006)

    SciTech Connect

    Hassett, D.; Heebink, L.V.; Pflughoeft-Hassett, D.

    2007-10-15

    The air toxic elements (ATEs) evaluated in this project were arsenic, cadmium, chromium, lead, nickel, and selenium. The study included laboratory tasks to develop measurement techniques for mercury and ATE releases, sample characterization, and release experiments. A field task was also performed to measure mercury releases at a field site. Results of laboratory evaluations indicated that: mercury and sometimes selenium are collected with activated carbon (AC) used for mercury emission control and, therefore present at higher concentrations than samples collected without mercury emission controls present. Mercury is stable on CCBs collected from systems both without and with mercury emission controls present under most conditions tested, with the exception of vapor-phase releases of mercury exposed to elevated temperatures. The presence of carbon either from added AC or from unburned coal can result in mercury being sorbed onto the CCB when exposed to ambient-temperature air. The environmental performance of the mercury captured on AC used as a sorbent for mercury emission control technologies indicated that current CCB management options will continue to be sufficiently protective of the environment, with the potential exception of exposure to elevated temperatures. The environmental performance of the other ATEs investigated indicated that current management options will be appropriate to the CCBs produced using AC in mercury emission controls. Field experiments vapor-phase releases at a CCB disposal site. Results indicated low-level vapor-phase mercury releases, as was generally noted in laboratory experiments for lignite fly ash samples. Laboratory methods were developed to evaluate the potential for mercury releases under several release mechanicals. 48 refs., 21 figs., 76 tabs., 21 apps.

  6. Symposium (International) on Combustion, 20th, University of Michigan, Ann Arbor, MI, August 12-17, 1984, Proceedings

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The present conference on combustion phenomena considers topics in automotive engine combustion, turbulent reacting flows, the modeling of practical combustion systems, reaction kinetics, combustion-generated particulates, combustion diagnostics, coal combustion process characteristics, fire-related phenomena, explosion/detonation phenomena, spray combustion, ignition/extinction, laminar flames, pollutant formation processes, practical combustor devices, and rocket propellant combustion. Attention is given to the contributions of combustion science to piston engine design, modeling and measurement techniques for turbulent combustion, the specific effects of energy, collisions, and transport processes in combustion chemistry kinetics, the formation of large molecules, particulates and ions in premixed hydrocarbon flames, the application of laser diagnostics to combustion systems, spark ignition energies for dust-air mixtures, the controlling mechanisms of flow-assisted flame spread, the ignition and combustion of coal-water slurries, spontaneous ignition of methane, turbulent and accelerating dust flames, and the temperature sensitivity of double base propellants.

  7. Advanced Control Methodology for Biomass Combustion

    NASA Astrophysics Data System (ADS)

    Bjornsson, Stefan

    This thesis presents a feasibility study for a low cost sensor-based combustion control system using a predictive chemical kinetic model that captures efficiencies and pollution emissions during biomass combustion. Low cost sensor module was developed, the sensors were calibrated to measure carbon monoxide and particulate matter (PM) in combustion exhaust. Major combustion species in the exhaust of a commercial biomass furnace, operating with white oak, were measured. The species concentrations were measured using the low cost sensors and commercially available diagnostics. The low cost sensor outputs compare well with the reference instruments and the sensors can be employed to measure varying concentration of CO and particulate matter in combustion exhaust. A predictive chemical kinetic model was generated to simulate biomass processes. The model uses a four element chemical reactor network (CRN) and successfully simulates smoldering, ignition and flaming combustion events. The model agrees with concentration of CO and particulate matter from experiments. The sensors and CRN model can be integrated in a control system for biomass combustion that can potentially improve combustion efficiency and reduce emissions of particulate matter, CO and unburned hydrocarbons that have been linked to urban and rural air pollution resulting in adverse health effects.

  8. Catalytic combustion of residual fuels

    NASA Technical Reports Server (NTRS)

    Bulzan, D. L.; Tacina, R. R.

    1981-01-01

    A noble metal catalytic reactor was tested using two grades of petroleum derived residual fuels at specified inlet air temperatures, pressures, and reference velocities. Combustion efficiencies greater than 99.5 percent were obtained. Steady state operation of the catalytic reactor required inlet air temperatures of at least 800 K. At lower inlet air temperatures, upstream burning in the premixing zone occurred which was probably caused by fuel deposition and accumulation on the premixing zone walls. Increasing the inlet air temperature prevented this occurrence. Both residual fuels contained about 0.5 percent nitrogen by weight. NO sub x emissions ranged from 50 to 110 ppm by volume at 15 percent excess O2. Conversion of fuel-bound nitrogen to NO sub x ranged from 25 to 50 percent.

  9. Active control of combustion for optimal performance

    SciTech Connect

    Jackson, M.D.; Agrawal, A.K.

    1999-07-01

    Combustion-zone stoichiometry and fuel-air premixing were actively controlled to optimize the combustor performance over a range of operating conditions. The objective was to maximize the combustion temperature, while maintaining NO{sub x} within a specified limit. The combustion system consisted of a premixer located coaxially near the inlet of a water-cooled shroud. The equivalence ratio was controlled by a variable-speed suction fan located downstream. The split between the premixing air and diffusion air was governed by the distance between the premixer and shroud. The combustor performance was characterized by a cost function evaluated from time-averaged measurements of NO{sub x} and oxygen concentrations in products. The cost function was minimized by downhill simplex algorithm employing closed-loop feedback. Experiments were conducted at different fuel flow rates to demonstrate that the controller optimized the performance without prior knowledge of the combustor behavior.

  10. Combustion instability modeling and analysis

    SciTech Connect

    Santoro, R.J.; Yang, V.; Santavicca, D.A.; Sheppard, E.J.

    1995-12-31

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors. The present study represents a coordinated effort between industry, government and academia to investigate gas turbine combustion dynamics. Specific study areas include development of advanced diagnostics, definition of controlling phenomena, advancement of analytical and numerical modeling capabilities, and assessment of the current status of our ability to apply these tools to practical gas turbine combustors. The present work involves four tasks which address, respectively, (1) the development of a fiber-optic probe for fuel-air ratio measurements, (2) the study of combustion instability using laser-based diagnostics in a high pressure, high temperature flow reactor, (3) the development of analytical and numerical modeling capabilities for describing combustion instability which will be validated against experimental data, and (4) the preparation of a literature survey and establishment of a data base on practical experience with combustion instability.

  11. Combustion 2000

    SciTech Connect

    2000-06-30

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench Scale Activities

  12. Ultra-lean combustion at high inlet temperatures

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.

    1981-01-01

    Combustion at inlet-air temperatures of 1100 to 1250 K was studied for application to advanced automotive gas turbine engines. Combustion was initiated by the hot environment, and therefore no external ignition source was used. Combustion was stabilized without a flameholder. The tests were performed in a 12-cm-diameter test section at a pressure of 250,000 Pa, with reference velocities of 32 to 60 m/s and at maximum combustion temperatures of 1350 to 1850 K. Number 2 diesel fuel was injected by means of a multiple-source fuel injector. Unburned hydrocarbon emissions were negligible for all test conditions. Nitrogen oxide emissions were less than 1.9 g NO2/kg fuel for combustion temperatures below 1680 K. Carbon monoxide emissions were less than 16 g CO/kg fuel for combustion temperatures greater than 1600 K, inlet-air temperatures higher than 1150 K, and residence times greater than 4.3 ms.

  13. Active Combustion Control for Aircraft Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

    DeLaat, John C.; Breisacher, Kevin J.; Saus, Joseph R.; Paxson, Daniel E.

    2000-01-01

    Lean-burning combustors are susceptible to combustion instabilities. Additionally, due to non-uniformities in the fuel-air mixing and in the combustion process, there typically exist hot areas in the combustor exit plane. These hot areas limit the operating temperature at the turbine inlet and thus constrain performance and efficiency. Finally, it is necessary to optimize the fuel-air ratio and flame temperature throughout the combustor to minimize the production of pollutants. In recent years, there has been considerable activity addressing Active Combustion Control. NASA Glenn Research Center's Active Combustion Control Technology effort aims to demonstrate active control in a realistic environment relevant to aircraft engines. Analysis and experiments are tied to aircraft gas turbine combustors. Considerable progress has been shown in demonstrating technologies for Combustion Instability Control, Pattern Factor Control, and Emissions Minimizing Control. Future plans are to advance the maturity of active combustion control technology to eventual demonstration in an engine environment.

  14. Calculation of the mass transfer coefficient for the combustion of a carbon particle

    SciTech Connect

    Scala, Fabrizio

    2010-01-15

    In this paper we address the calculation of the mass transfer coefficient around a burning carbon particle in an atmosphere of O{sub 2}, N{sub 2}, CO{sub 2}, CO, and H{sub 2}O. The complete set of Stefan-Maxwell equations is analytically solved under the assumption of no homogeneous reaction in the boundary layer. An expression linking the oxygen concentration and the oxygen flux at the particle surface (as a function of the bulk gas composition) is derived which can be used to calculate the mass transfer coefficient. A very simple approximate explicit expression is also given for the mass transfer coefficient, that is shown to be valid in the low oxygen flux limit or when the primary combustion product is CO{sub 2}. The results are given in terms of a correction factor to the equimolar counter-diffusion mass transfer coefficient, which is typically available in the literature for specific geometries and/or fluid-dynamic conditions. The significance of the correction factor and the accuracy of the different available expressions is illustrated for several cases of practical interest. Results show that under typical combustion conditions the use of the equimolar counter-diffusion mass transfer coefficient can lead to errors up to 10%. Larger errors are possible in oxygen-enriched conditions, while the error is generally low in oxy-combustion. (author)

  15. A laboratory scale supersonic combustive flow system

    SciTech Connect

    Sams, E.C.; Zerkle, D.K.; Fry, H.A.; Wantuck, P.J.

    1995-02-01

    A laboratory scale supersonic flow system [Combustive Flow System (CFS)] which utilizes the gaseous products of methane-air and/or liquid fuel-air combustion has been assembled to provide a propulsion type exhaust flow field for various applications. Such applications include providing a testbed for the study of planar two-dimensional nozzle flow fields with chemistry, three-dimensional flow field mixing near the exit of rectangular nozzles, benchmarking the predictive capability of various computational fluid dynamic codes, and the development and testing of advanced diagnostic techniques. This paper will provide a detailed description of the flow system and data related to its operation.

  16. Plasma igniter for internal combustion engine

    NASA Technical Reports Server (NTRS)

    Fitzgerald, D. J.; Breshears, R. R. (Inventor)

    1978-01-01

    An igniter for the air/fuel mixture used in the cylinders of an internal combustion engine is described. A conventional spark is used to initiate the discharge of a large amount of energy stored in a capacitor. A high current discharge of the energy in the capacitor switched on by a spark discharge produces a plasma and a magnetic field. The resultant combined electromagnetic current and magnetic field force accelerates the plasma deep into the combustion chamber thereby providing an improved ignition of the air/fuel mixture in the chamber.

  17. Constant-Pressure Combustion Charts Including Effects of Diluent Addition

    NASA Technical Reports Server (NTRS)

    Turner, L Richard; Bogart, Donald

    1949-01-01

    Charts are presented for the calculation of (a) the final temperatures and the temperature changes involved in constant-pressure combustion processes of air and in products of combustion of air and hydrocarbon fuels, and (b) the quantity of hydrocarbon fuels required in order to attain a specified combustion temperature when water, alcohol, water-alcohol mixtures, liquid ammonia, liquid carbon dioxide, liquid nitrogen, liquid oxygen, or their mixtures are added to air as diluents or refrigerants. The ideal combustion process and combustion with incomplete heat release from the primary fuel and from combustible diluents are considered. The effect of preheating the mixture of air and diluents and the effect of an initial water-vapor content in the combustion air on the required fuel quantity are also included. The charts are applicable only to processes in which the final mixture is leaner than stoichiometric and at temperatures where dissociation is unimportant. A chart is also included to permit the calculation of the stoichiometric ratio of hydrocarbon fuel to air with diluent addition. The use of the charts is illustrated by numerical examples.

  18. Relationship between pulmonary function and indoor air pollution from coal combustion among adult residents in an inner-city area of southwest China

    PubMed Central

    Jie, Y.; Houjin, H.; Xun, M.; Kebin, L.; Xuesong, Y.; Jie, X.

    2014-01-01

    Few studies evaluate the amount of particulate matter less than 2.5 mm in diameter (PM2.5) in relation to a change in lung function among adults in a population. The aim of this study was to assess the association of coal as a domestic energy source to pulmonary function in an adult population in inner-city areas of Zunyi city in China where coal use is common. In a cross-sectional study of 104 households, pulmonary function measurements were assessed and compared in 110 coal users and 121 non-coal users (≥18 years old) who were all nonsmokers. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), the FEV1/FVC ratio, and peak expiratory flow rate (PEFR) were compared between the 2 groups. The amount of PM2.5 was also measured in all residences. There was a significant increase in the relative concentration of PM2.5 in the indoor kitchens and living rooms of the coal-exposed group compared to the non-coal-exposed group. In multivariate analysis, current exposure to coal smoke was associated with a 31.7% decrease in FVC, a 42.0% decrease in FEV1, a 7.46% decrease in the FEV1/FVC ratio, and a 23.1% decrease in PEFR in adult residents. The slope of lung function decrease for Chinese adults is approximately a 2-L decrease in FVC, a 3-L decrease in FEV1, and an 8 L/s decrease in PEFR per count per minute of PM2.5 exposure. These results demonstrate the harmful effects of indoor air pollution from coal smoke on the lung function of adult residents and emphasize the need for public health efforts to decrease exposure to coal smoke. PMID:25296361

  19. Relationship between pulmonary function and indoor air pollution from coal combustion among adult residents in an inner-city area of southwest China.

    PubMed

    Jie, Y; Houjin, H; Xun, M; Kebin, L; Xuesong, Y; Jie, X

    2014-11-01

    Few studies evaluate the amount of particulate matter less than 2.5 mm in diameter (PM₂.₅) in relation to a change in lung function among adults in a population. The aim of this study was to assess the association of coal as a domestic energy source to pulmonary function in an adult population in inner-city areas of Zunyi city in China where coal use is common. In a cross-sectional study of 104 households, pulmonary function measurements were assessed and compared in 110 coal users and 121 non-coal users (≥18 years old) who were all nonsmokers. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), the FEV₁/FVC ratio, and peak expiratory flow rate (PEFR) were compared between the 2 groups. The amount of PM₂.₅ was also measured in all residences. There was a significant increase in the relative concentration of PM₂.₅ in the indoor kitchens and living rooms of the coal-exposed group compared to the non-coal-exposed group. In multivariate analysis, current exposure to coal smoke was associated with a 31.7% decrease in FVC, a 42.0% decrease in FEV₁, a 7.46% decrease in the FEV₁/FVC ratio, and a 23.1% decrease in PEFR in adult residents. The slope of lung function decrease for Chinese adults is approximately a 2-L decrease in FVC, a 3-L decrease in FEV₁, and an 8 L/s decrease in PEFR per count per minute of PM₂.₅ exposure. These results demonstrate the harmful effects of indoor air pollution from coal smoke on the lung function of adult residents and emphasize the need for public health efforts to decrease exposure to coal smoke. PMID:25296361

  20. System and method for cooling a combustion gas charge

    DOEpatents

    Massey, Mary Cecelia; Boberg, Thomas Earl

    2010-05-25

    The present invention relates to a system and method for cooling a combustion gas charge prior. The combustion gas charge may include compressed intake air, exhaust gas, or a mixture thereof. An evaporator is provided that may then receive a relatively high temperature combustion gas charge and discharge at a relatively lower temperature. The evaporator may be configured to operate with refrigeration cycle components and/or to receive a fluid below atmospheric pressure as the phase-change cooling medium.

  1. Optical fiber system for combustion quality analysis in power boilers

    NASA Astrophysics Data System (ADS)

    Wojcik, Waldemar; Surtel, Wojciech; Smolarz, Andrzej; Kotyra, Andrzej; Komada, Pawel

    2001-06-01

    The introduction of low emission techniques of combustion caused side-effects like oxygen lean corrosion. It also enforced more precise management of technological air, better coal milling and application of devices for combustion process monitoring. In the article authors presented their own solution of optical fiber system for combustion quality evaluation, already operating on power boiler type OP-650. Its functionality was described together with selected results of measurements. Directions of further development of the system were also indicated.

  2. Rotary valve internal combustion engine

    SciTech Connect

    Coman, C.R.

    1987-04-21

    A rotary valve internal combustion engine is described which comprises: a cylinder block having a cylindrical recess therein, a cylindrical bore transverse to the cylindrical recess, an exhaust passageway leading from the cylindrical bore, and an intake passageway leading to the cylindrical bore. A cylindrical piston sealably reciprocable in the cylindrical recess wherein the space defined by the piston and the walls of the cylindrical recess forms a combustion chamber. An arcuate passageway in the block between the cylindrical bore and the combustion chamber; a crankshaft connected to the piston; ignition means in communication with the combustion chamber; carburetion means in connection with the intake passageway to provide a fuel-air mixture; a cylindrical valve rotatably received in the cylindrical bore, the cylindrical valve having a hollow cylindrical body, open ends, at least two axially aligned intake ports near one end of the cylindrical body, at least two axially aligned exhaust ports near the opposite end of the cylindrical body, at least four axially aligned arcuate center openings between the exhaust ports and the intake ports, and at least for internal tubes, each tube connecting one of the center openings with one of the intake or exhaust ports; a sprocket wheel extending from one end of the cylindrical valve; and a tooth belt extending between the sprocket wheel and the crankshaft.

  3. Combustion 2000

    SciTech Connect

    1999-12-31

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site-specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench Scale Activities

  4. TOXIC SUBSTANCES FROM COAL COMBUSTION

    SciTech Connect

    Kolker, A.; Sarofim, A.F.; Palmer, C.A.; Huggins, F.E.; Huffman, G.P.; Lighty, J.; Veranth, J.; Helble, J.J.; Wendt, J.O.L.; Ames, M.R.; Finkelman, R.; Mamani-Paco, M.; Sterling, R.; Mroczkowsky, S.J.; Panagiotou, T.; Seames, W.

    1999-05-10

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environ-mental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 January 1999 to 31 March 1999. During this period, a full Program Review Meeting was held at the University of Arizona. At this meeting, the progress of each group was reviewed, plans for the following 9 month period were discussed, and action items (principally associated with the transfer of samples and reports among the various investigators) were identified.

  5. Modeling the internal combustion engine

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.; Mcbride, B. J.

    1985-01-01

    A flexible and computationally economical model of the internal combustion engine was developed for use on large digital computer systems. It is based on a system of ordinary differential equations for cylinder-averaged properties. The computer program is capable of multicycle calculations, with some parameters varying from cycle to cycle, and has restart capabilities. It can accommodate a broad spectrum of reactants, permits changes in physical properties, and offers a wide selection of alternative modeling functions without any reprogramming. It readily adapts to the amount of information available in a particular case because the model is in fact a hierarchy of five models. The models range from a simple model requiring only thermodynamic properties to a complex model demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. Among its many features the model includes heat transfer, valve timing, supercharging, motoring, finite burning rates, cycle-to-cycle variations in air-fuel ratio, humid air, residual and recirculated exhaust gas, and full combustion kinetics.

  6. Chemical Looping Combustion Kinetics

    SciTech Connect

    Edward Eyring; Gabor Konya

    2009-03-31

    One of the most promising methods of capturing CO{sub 2} emitted by coal-fired power plants for subsequent sequestration is chemical looping combustion (CLC). A powdered metal oxide such as NiO transfers oxygen directly to a fuel in a fuel reactor at high temperatures with no air present. Heat, water, and CO{sub 2} are released, and after H{sub 2}O condensation the CO{sub 2} (undiluted by N{sub 2}) is ready for sequestration, whereas the nickel metal is ready for reoxidation in the air reactor. In principle, these processes can be repeated endlessly with the original nickel metal/nickel oxide participating in a loop that admits fuel and rejects ash, heat, and water. Our project accumulated kinetic rate data at high temperatures and elevated pressures for the metal oxide reduction step and for the metal reoxidation step. These data will be used in computational modeling of CLC on the laboratory scale and presumably later on the plant scale. The oxygen carrier on which the research at Utah is focused is CuO/Cu{sub 2}O rather than nickel oxide because the copper system lends itself to use with solid fuels in an alternative to CLC called 'chemical looping with oxygen uncoupling' (CLOU).

  7. Stoichiometric Experiments with Alkane Combustion: A Classroom Demonstration

    ERIC Educational Resources Information Center

    Zhilin, Denis M.

    2012-01-01

    A simple, effective demonstration of the concept of limiting and excess reagent is presented. Mixtures of either air/methane (from a gas line) or air/butane (from a disposable cigarette lighter) contained in a plastic 2 L soda bottles are ignited. The mixtures combust readily when air/fuel ratios are stoichiometric, but not at a 2-fold excess of…

  8. Free-radicals aided combustion with scramjet applications

    NASA Technical Reports Server (NTRS)

    Yang, Yongsheng; Kumar, Ramohalli

    1992-01-01

    Theoretical and experimental investigations aimed at altering 'nature-prescribed' combustion rates in hydrogen/hydrocarbon reactions with (enriched) air are presented. The intent is to anchor flame zones in supersonic streams, and to ensure proper and controllable complete combustion in scramjets. The diagnostics are nonintrusive through IR thermograms and acoustic emissions in the control and free-radicals altered flame zones.

  9. Fluidic systems may improve combustion in automotive engines

    NASA Technical Reports Server (NTRS)

    Mangion, C.

    1972-01-01

    Application of fluidic devices to reduce generation of noxious exhausts from internal combustion engines is discussed. Operation of fluidic system to provide bypass of fuel air mixture into heated loop to provide more complete combustion is explanined. Advantage lies in no moving parts required for fluidic by-pass action.

  10. Apparatus for the premixed gas phase combustion of liquid fuels

    SciTech Connect

    Roffe, G.A.; Trucco, H.A.

    1981-04-21

    This invention relates to improvements in the art of liquid fuel combustion and, more particularly, concerns a method and apparatus for the controlled gasification of liquid fuels, the thorough premixing of the then gasified fuel with air and the subsequent gas-phase combustion of the mixture to produce a flame substantially free of soot, carbon monoxide, nitric oxide and unburned fuel.

  11. DEMONSTRATION BULLETIN: THE PYRETRON OXYGEN BURNER, AMERICAN COMBUSTION TECHNOLOGIES, INC.

    EPA Science Inventory

    The Pyretron is a burner which is designed to allow for the injection of oxygen into the combustion air stream for the purpose of increasing the efficiency of a hazardous waste incinerator. The SITE demonstration of the Pyretron took place at the U.S. EPA's Combustion Re...

  12. Fundamentals of Gas Turbine combustion

    NASA Technical Reports Server (NTRS)

    Gerstein, M.

    1979-01-01

    Combustion problems and research recommendations are discussed in the areas of atomization and vaporization, combustion chemistry, combustion dynamics, and combustion modelling. The recommendations considered of highest priority in these areas are presented.

  13. Oil shale retorting and combustion system

    DOEpatents

    Pitrolo, Augustine A.; Mei, Joseph S.; Shang, Jerry Y.

    1983-01-01

    The present invention is directed to the extraction of energy values from l shale containing considerable concentrations of calcium carbonate in an efficient manner. The volatiles are separated from the oil shale in a retorting zone of a fluidized bed where the temperature and the concentration of oxygen are maintained at sufficiently low levels so that the volatiles are extracted from the oil shale with minimal combustion of the volatiles and with minimal calcination of the calcium carbonate. These gaseous volatiles and the calcium carbonate flow from the retorting zone into a freeboard combustion zone where the volatiles are burned in the presence of excess air. In this zone the calcination of the calcium carbonate occurs but at the expense of less BTU's than would be required by the calcination reaction in the event both the retorting and combustion steps took place simultaneously. The heat values in the products of combustion are satisfactorily recovered in a suitable heat exchange system.

  14. Internal combustion engine with multiple combustion chambers

    SciTech Connect

    Gruenwald, D.J.

    1992-05-26

    This patent describes a two-cycle compression ignition engine. It comprises one cylinder, a reciprocable piston moveable in the cylinder, a piston connecting rod, a crankshaft for operation of the piston connecting rod, a cylinder head enclosing the cylinder, the upper surface of the piston and the enclosing surface of the cylinder head defining a cylinder clearance volume, a first combustion chamber and a second combustion chamber located in the cylinder head. This patent describes improvement in means for isolating the combustion process for one full 360{degrees} rotation of the crankshaft; wherein the combustion chambers alternatively provide for expansion of combustion products in the respective chambers into the cylinder volume near top dead center upon each revolution of the crankshaft.

  15. Coal-water slurry fuel internal combustion engine and method for operating same

    DOEpatents

    McMillian, Michael H.

    1992-01-01

    An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.

  16. Maximal combustion temperature estimation

    NASA Astrophysics Data System (ADS)

    Golodova, E.; Shchepakina, E.

    2006-12-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models.

  17. Combustion device for liquid fuels

    SciTech Connect

    Kawasaki, Y.; Ohmukai, Y.; Tomisawa, T.

    1980-10-21

    A device is described which includes a porous burner head capable of containing a liquid fuel in a liquid state and in which air is supplied to the surface of the burner head to vaporize and burn the fuel contained therein. The burner head is made of a heat resistant porous material having extending therethrough minute channels which are predominantly up to 100 mu M in diameter and give the burner head a porosity of at least 25%. The burner head is capable of raising the liquid fuel at a rate of at least 0.001 g/cm/sub 2/ min to a height of up to 70 mm. The use of the burner head assures clean combustion and high combustion efficiency.

  18. Fluidized bed coal combustion reactor

    NASA Technical Reports Server (NTRS)

    Moynihan, P. I.; Young, D. L. (Inventor)

    1981-01-01

    A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

  19. Fluidized bed coal combustion reactor

    SciTech Connect

    Moynihan, P.I.; Young, D.L.

    1981-09-01

    A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor. Official Gazette of the U.S. Patent and Trademark Office

  20. Oxy-coal Combustion Studies

    SciTech Connect

    Wendt, J.; Eddings, E.; Lighty, J.; Ring, T.; Smith, P.; Thornock, J.; Y Jia, W. Morris; Pedel, J.; Rezeai, D.; Wang, L.; Zhang, J.; Kelly, K.

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  1. Fundamental studies of spray combustion

    SciTech Connect

    Li, S.C.; Libby, P.A.; Williams, F.A.

    1997-12-31

    Our research on spray combustion involves both experiment and theory and addresses the characteristics of individual droplets and of sprays in a variety of flows: laminar and turbulent, opposed and impinging. Currently our focus concerns water and fuel sprays in two stage laminar flames, i.e., flames arising, for example from a stream of fuel and oxidizer flowing opposite to an air stream carrying a water spray. Our interest in these flames is motivated by the goals of reducing pollutant emissions and extending the range of stable spray combustion. There remains considerable research to be carried out in order to achieve these goals. Thus far our research on the characteristics of sprays in turbulent flows has been limited to nonreacting jets impinging on a plate but this work will be extended to opposed flows with and without a flame. In the following we discuss details of these studies and our plans for future work.

  2. Internal combustion engine

    SciTech Connect

    Evans, H.G.; Speer, S.

    1991-12-31

    This patent describes improvement in a 2-cycle, diesel cycle internal combustion engine comprising a single in-line engine block, internal wall surfaces defining at least one cylinder within the engine block, the central longitudinal axis of each cylinder being within a common plane extending longitudinally of the engine block, the axially extending internal wall surface of each cylinder being closed at one end and having at least one air intake port therethrough, a piston axially and reciprocally movable within each cylinder over a permitted stroke distance, so as to alternately cover and expose each air intake port for a finite time period; an exhaust port at the closed end of the cylinder above the piston, and a mechanically operated valve for opening and closing such exhaust port located immediately adjacent such port, a substantially rigid connecting rod pivotably connected at one end of each piston, and a crankshaft, rotatably connected to the second end of each connecting rod, such that the crankshaft is caused to rotate connecting means between the piston and the connecting rod. The improvement comprises the diameter of the cylinder is greater than the permitted stroke distance of the piston within the cylinder, and the axis of the crankshaft is parallel to and laterally offset from the common plane by a distance sufficient to form an angle alpha between the connecting rod and the axis of the cylinder, when the piston is at top-dead center, of at least about 12 degrees, such that the time during which each air intake port is exposed is increased when the direction of crankshaft rotation is opposite to the direction of the crankshaft offset from the common plane.

  3. AIR POLLUTION CONTROL TECHNOLOGIES (CHAPTER 65)

    EPA Science Inventory

    The chapter discusses the use of technologies for reducing air pollution emissions from stationary sources, with emphasis on the control of combustion gen-erated air pollution. Major stationary sources include utility power boilers, industrial boilers and heaters, metal smelting ...

  4. Mechanisms of droplet combustion

    NASA Technical Reports Server (NTRS)

    Law, C. K.

    1982-01-01

    The fundamental physico-chemical mechanisms governing droplet vaporization and combustion are discussed. Specific topics include governing equations and simplifications, the classical d(2)-Law solution and its subsequent modification, finite-rate kinetics and the flame structure, droplet dynamics, near- and super-critical combustion, combustion of multicomponent fuel blends/emulsions/suspensions, and droplet interaction. Potential research topics are suggested.

  5. Recent Advances in Combustion Technology for Heating Processes

    NASA Astrophysics Data System (ADS)

    Katsuki, Masashi

    Recent advancement in industrial furnaces brought by highly preheated air combustion is reviewed. Highly Preheated Air Combustion in regenerative furnaces has been paid much attention for its accomplishment in not only energy saving but also low nitric oxides emission. Characteristics of combustion with highly preheated air were studied to understand the change of combustion regime and the reason for the compatibility between high performance and low nitric oxides emission. It was found that combustion was sustained even in an extremely low concentration of oxygen if the temperature of oxidizer was higher than the auto-ignition temperature of the fuel. As an application of the principle, we can reduce nitric oxides emission by dilution of combustion air with plenty of recirculated burned gas in the furnace. Dilution makes the oxygen content of the oxidizer low, which decreases temperature fluctuations in flames as well as the mean temperature, hence low nitric oxides emission. Finally, the applicability of highly preheated air combustion to other fields than industrial furnaces has been discussed.

  6. Methods and systems for combustion dynamics reduction

    DOEpatents

    Kraemer, Gilbert Otto; Varatharajan, Balachandar; Srinivasan, Shiva; Lynch, John Joseph; Yilmaz, Ertan; Kim, Kwanwoo; Lacy, Benjamin; Crothers, Sarah; Singh, Kapil Kumar

    2009-08-25

    Methods and systems for combustion dynamics reduction are provided. A combustion chamber may include a first premixer and a second premixer. Each premixer may include at least one fuel injector, at least one air inlet duct, and at least one vane pack for at least partially mixing the air from the air inlet duct or ducts and fuel from the fuel injector or injectors. Each vane pack may include a plurality of fuel orifices through which at least a portion of the fuel and at least a portion of the air may pass. The vane pack or packs of the first premixer may be positioned at a first axial position and the vane pack or packs of the second premixer may be positioned at a second axial position axially staggered with respect to the first axial position.

  7. Turbocharger for internal combustion engines

    SciTech Connect

    Kawamura, H.

    1988-09-13

    This patent describes a turbocharger for an internal combustion engine having engine cylinders, comprising: a turbine drivable by the exhaust energy of the internal combustion engine and having an impeller; an air compressor coupled by a shaft to the impeller for charging air into the engine cylinders in response to rotation of the shaft; a motor-generator having a rotor with a substantially I-shaped cross section mounted on the shaft, and stator coils disposed around the rotor. The rotor having an axial length longer than the diameter of the rotor, a magnetic path in the direction of the diameter of the rotor, dummy fillers which fill a part other than the magnetic path of the rotor to define a circular cross-section with the rotor, the magnetic path being fixedly secured to the dummy fillers, and an axially elongate, ring-shaped, rare-earth metal magnet constructed as a portion of the shaft and having a magnetic reluctance in a first direction normal to an axis of the shaft smaller than a magnetic reluctance in a second direction normal to the first direction and to the axis of the shaft, and an outer periphery of which is wound with carbon fibers; disks made of a metal of high tensile strength for holding the opposite ends of the magnet, respectively; and control means for operating the motor-generator as a motor under first operating conditions of the internal combustion engine, and as a generator under second operating conditions of the internal combustion engine, and means for supplying the stator coils with armature current leading a no-lead induced electromotive force by 90.

  8. Results from study of potential early commercial MHD power plants and from recent ETF design work. [Engineering Test Facility

    NASA Technical Reports Server (NTRS)

    Hals, F.; Kessler, R.; Swallom, D.; Westra, L.; Zar, J.; Morgan, W.; Bozzuto, C.

    1980-01-01

    The study deals with different 'moderate technology' entry-level commercial MHD power plants. Two of the reference plants are based on combustion of coal with air preheated in a high-temperature regenerative air heater separately fired with a low-BTU gas produced in a gasifier integrated with the power plant. The third reference plant design is based on the use of oxygen enriched combustion air. Performance calculations show that an overall power plant efficiency of the order of 44% can be reached with the use of oxygen enrichment.

  9. Starting procedure for internal combustion vessels

    DOEpatents

    Harris, Harry A.

    1978-09-26

    A vertical vessel, having a low bed of broken material, having included combustible material, is initially ignited by a plurality of ignitors spaced over the surface of the bed, by adding fresh, broken material onto the bed to buildup the bed to its operating depth and then passing a combustible mixture of gas upwardly through the material, at a rate to prevent back-firing of the gas, while air and recycled gas is passed through the bed to thereby heat the material and commence the desired laterally uniform combustion in the bed. The procedure permits precise control of the air and gaseous fuel mixtures and material rates, and permits the use of the process equipment designed for continuous operation of the vessel.

  10. Symposium (International) on Combustion, 18th, 1980

    SciTech Connect

    Anon

    1980-08-01

    This conference proceedings contains 196 papers. 181 papers are indexed separately. Topics covered include: combustion generated pollution; propellant combustion; fluidized bed combustion; combustion of droplets and spray; premixed flame studies; fire studies; flame stabilization; coal flammability; chemical kinetics; turbulent combustion; soot; coal combustion; modeling of combustion processes; combustion diagnostics; detonations and explosions; ignition; internal combustion engines; combustion studies; and furnaces.

  11. Device for controlling ignition timing in internal combustion engine

    SciTech Connect

    Tanaka, A.

    1988-01-12

    A device for controlling ignition timing in an internal combustion engine is described comprising: a. combustion state detection means disposed in the vicinity of the combustion chamber of each cylinder of an internal combustion engine for detecting the state of combustion in the combustion chamber, b. crankshaft angle detection means disposed in the vicinity of the rotating member of the internal combustion engine for detecting the angular position of a crankshaft of the internal combustion engine, c. maximum cylinder pressure angle calculation means which receives the outputs of the combustion state detection means and the crankshaft angle detection means and calculates the maximum cylinder pressure angle, d. cylinder pressure calculation means which receives the output of the combustion state detection means and calculates the cylinder pressure, e. ignition timing calculation means which receives the outputs of the crankshaft angle detection means, the maximum cylinder pressure angle calculation means and the cylinder pressure calculation means and calculates the ignition timing such that the maximum cylinder pressure angle converges on a target angle, and f. ignition means which receives the output of the ignition timing calculation means and ignites a fuel and air mixture in the combustion chamber, whereby the ignition timing calculation means detecting transient conditions in the engine driving operation on the basis of the output of the cylinder pressure calculation means.

  12. Combustion of Methane Hydrate

    NASA Astrophysics Data System (ADS)

    Roshandell, Melika

    A significant methane storehouse is in the form of methane hydrates on the sea floor and in the arctic permafrost. Methane hydrates are ice-like structures composed of water cages housing a guest methane molecule. This caged methane represents a resource of energy and a potential source of strong greenhouse gas. Most research related to methane hydrates has been focused on their formation and dissociation because they can form solid plugs that complicate transport of oil and gas in pipelines. This dissertation explores the direct burning of these methane hydrates where heat from the combustion process dissociates the hydrate into water and methane, and the released methane fuels the methane/air diffusion flame heat source. In contrast to the pipeline applications, very little research has been done on the combustion and burning characteristics of methane hydrates. This is the first dissertation on this subject. In this study, energy release and combustion characteristics of methane hydrates were investigated both theoretically and experimentally. The experimental study involved collaboration with another research group, particularly in the creation of methane hydrate samples. The experiments were difficult because hydrates form at high pressure within a narrow temperature range. The process can be slow and the resulting hydrate can have somewhat variable properties (e.g., extent of clathration, shape, compactness). The experimental study examined broad characteristics of hydrate combustion, including flame appearance, burning time, conditions leading to flame extinguishment, the amount of hydrate water melted versus evaporated, and flame temperature. These properties were observed for samples of different physical size. Hydrate formation is a very slow process with pure water and methane. The addition of small amounts of surfactant increased substantially the hydrate formation rate. The effects of surfactant on burning characteristics were also studied. One finding

  13. Millwright Apprenticeship. Related Training Modules. 10.1-10.5 Combustion.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This packet, part of the instructional materials for the Oregon apprenticeship program for millwright training, contains five modules covering combustion. The modules provide information on the following topics: the combustion process, types of fuel, air and fuel gases, heat transfer, and combustion in wood. Each module consists of a goal,…

  14. Combustion characteristics of gas turbine alternative fuels

    NASA Technical Reports Server (NTRS)

    Rollbuhler, R. James

    1987-01-01

    An experimental investigation was conducted to obtain combustion performance values for specific heavyend, synthetic hydrocarbon fuels. A flame tube combustor modified to duplicate an advanced gas turbine engine combustor was used for the tests. Each fuel was tested at steady-state operating conditions over a range of mass flow rates, fuel-to-air mass ratio, and inlet air temperatures. The combustion pressure, as well as the hardware, were kept nearly constant over the program test phase. Test results were obtained in regards to geometric temperature pattern factors as a function of combustor wall temperatures, the combustion gas temperature, and the combustion emissions, both as affected by the mass flow rate and fuel-to-air ratio. The synthetic fuels were reacted in the combustor such that for most tests their performance was as good, if not better, than the baseline gasoline or diesel fuel tests. The only detrimental effects were that at high inlet air temperature conditions, fuel decomposition occurred in the fuel atomizing nozzle passages resulting in blockage. And the nitrogen oxide emissions were above EPA limits at low flow rate and high operating temperature conditions.

  15. NOx Emission Reduction by Oscillating Combustion

    SciTech Connect

    2005-09-01

    This project focuses on a new technology that reduces NOx emissions while increasing furnace efficiency for both air- and oxygen-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace.

  16. AN OVERVIEW OF EPA'S COMBUSTION RESEARCH PROGRAM

    EPA Science Inventory

    The Air Pollution Technology Branch (APTB) of the U.S. Environmental Protection Agency's National Risk Management Research Laboratory, located in Research Triangle Park, North Carolina, performs a variety of combustion related research. Currently APTB's focus is on mercury from c...

  17. Hydrogen-oxygen powered internal combustion engine

    NASA Technical Reports Server (NTRS)

    Cameron, H.; Morgan, N.

    1970-01-01

    Hydrogen at 300 psi and oxygen at 800 psi are injected sequentially into the combustion chamber to form hydrogen-rich mixture. This mode of injection eliminates difficulties of preignition, detonation, etc., encountered with carburated, spark-ignited, hydrogen-air mixtures. Ignition at startup is by means of a palladium catalyst.

  18. CONTROLLING EMISSIONS FROM FUEL AND WASTE COMBUSTION

    EPA Science Inventory

    Control of emissions from combustion of fuels and wastes has been a traditional focus of air pollution regulations. Significant technology developments of the '50s and '60s have been refined into reliable chemical and physical process unit operations. In the U.S., acid rain legis...

  19. Combustion and core noise

    NASA Astrophysics Data System (ADS)

    Mahan, J. Robert; Karchmer, Allen

    1991-08-01

    Two types of aircraft power plant are considered: the gas turbine and the reciprocating engine. The engine types considered are: the reciprocating engine, the turbojet engine, the turboprop engine, and the turbofan engine. Combustion noise in gas turbine engines is discussed, and reciprocating-engine combustion noise is also briefly described. The following subject areas are covered: configuration variables, operational variables, characteristics of combustion and core noise, sources of combustion noise, combustion noise theory and comparison with experiment, available prediction methods, diagnostic techniques, measurement techniques, data interpretation, and example applications.

  20. High efficiency stoichiometric internal combustion engine system

    DOEpatents

    Winsor, Richard Edward; Chase, Scott Allen

    2009-06-02

    A power system including a stoichiometric compression ignition engine in which a roots blower is positioned in the air intake for the engine to control air flow. Air flow is decreased during part power conditions to maintain the air-fuel ratio in the combustion chamber of the engine at stoichiometric, thus enabling the use of inexpensive three-way catalyst to reduce oxides of nitrogen. The roots blower is connected to a motor generator so that when air flow is reduced, electrical energy is stored which is made available either to the roots blower to temporarily increase air flow or to the system electrical load and thus recapture energy that would otherwise be lost in reducing air flow.