Sample records for oxygen-enriched combustion air

  1. The Economics of Oxygen Enriched Air Production Via Membranes 

    E-print Network

    Gollan, A.; Kleper, M. H.

    1984-01-01

    Oxygen enriched air combustion is a recognized approach to energy conservation. Conventional methods of producing oxygen enriched air: Pressure Swing Adsorption and Cryogenics, are energy-intensive and expensive. In this paper the economics of using...

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

    SciTech Connect

    Poola, R.B.; Sekar, R. [Argonne National Lab., IL (United States); Assanis, D.N. [Michigan Univ., Ann Arbor, MI (United States); Cataldi, G.R. [Association of American Railroads, Washington, DC (United States)

    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.

  3. 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 experiment.

  4. Oxygen enriched combustion system performance study

    Microsoft Academic Search

    M. A. Delano; Y. Kwan

    1989-01-01

    The current study was undertaken to evaluate the performance of a pressure swing adsorption (PSA) oxygen plant to provide oxygen for industrial combustion applications. PSA oxygen plants utilize a molecular sieve material to separate air into an oxygen rich product stream and a nitrogen rich exhaust stream. These plants typically produce 90-95% purity oxygen and are located in close proximity

  5. Impact of oxygen enriched combustion on heat release curves of a Single Cylinder Diesel engine

    Microsoft Academic Search

    K. Rajkumar; P. Govindarajan

    2010-01-01

    In the present experimental work a computerized Single cylinder Diesel engine with data acquisition system was used to study the effects of oxygen enriched air intake on heat release rate. Increasing the oxygen content with the air leads to faster burn rates and the ability to burn more fuel at the same stoichiometry. Added oxygen in the combustion air offers

  6. Combustion of coal chars in oxygen-enriched atmospheres

    SciTech Connect

    Bejarano, P.A.; Levendis, Y.A. [Northeastern University, Boston, MA (United States)

    2007-07-01

    This work pertains to the high-temperature combustion of pulverized coal chars under oxygen-enriched atmospheres. Single char particles were burned in a drop-tube furnace, electrically-heated to 1300-1500 K, in 21%, 50% and 100% O{sub 2}, in a balance of N{sub 2}. Their luminous combustion histories were observed with two-color ratio pyrometry. A solution of the Planckian ratio-pyrometry equation for temperature was implemented, extending on Wien's approximation. The temperature and time histories for 45-53 {mu}m bituminous chars experienced wide particle-to-particle disparity, and varied depending on oxygen mole fraction and furnace temperature. Average char surface temperatures increased from 1600-1800 K in air, to 2100-2300 K in 50% O-2, to 2300-2400 K in 100% O{sub 2}, at gas temperatures of 1300-1500 K, respectively. Combustion durations decreased from 25-45 ms in air, to 8-17 ms in 50% O{sub 2}, to 6-13 in 100% O{sub 2}. Thus, average particle temperatures increased by up to 45%, whereas burnout times decreased by up to 87% as combustion was progressively enriched in O{sub 2} until 100% was attained. The apparent and intrinsic reactivity of the chars burning at 1500 K gas temperature were found to increase by factors of to 8 and 35, respectively, as the oxygen mole fraction increased by a factor of five, from 21% to 100%.

  7. 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.

  8. Experimental Research of the Oxygen-Enriched Combustion of Sewage Sludge and Coal in CFB

    NASA Astrophysics Data System (ADS)

    Xin, S. W.; Lu, X. F.; Liu, H. Z.

    Sewage sludge is the by-products of sewage treatment, and it is a fuel of high moisture, high ash and low caloric. Oxygen-enriched combustion technology is one of the new and clean coal combustion technologies that can control pollutant emission, which makes CO2 separation, SO2 treatment become easier, and NOx emission reduced. In this paper, we carried out the experimental research on the advantages of oxygen-enriched combustion and the characteristics of sewage sludge in a CFB incinerator that the diameter of the furnace is 100 mm, It is an important foundation for the industrialized application of the oxygen-enriched combustion of sewage sludge and coal in CFB. Experimental analyzed on the combustion characteristics of three conditions in the oxygen concentration of 21%˜35%, which were the weight ratio of coal and sludge were 1?1, 1?2 and also the coal was given. Furthermore, the change of gas composition along with the change of oxygen content and the temperature of dense phase region was analyzed. The results showed that the combustion characteristics differ from the different mixing rate between coal and sludge in different oxygen atmosphere, when the fluidized air velocity was 1.56 m/s˜1.88 m/s, the combustion stability; When the amount of the fuel was constant, as the increase of the oxygen contents in the experimental atmosphere, the total air volume decreased, the furnace temperature increased gradually, the concentration of SO2 and NOx showed increasing trend, which is beneficial to the removal of SO2; The concentration of NOx was increased gradually as temperature of the fluidized bed increased.

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

    SciTech Connect

    Poola, Ramesh B. (Woodridge, IL); Sekar, Ramanujam R. (Naperville, IL); Stork, Kevin C. (Chicago, IL)

    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.

  11. 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.

  12. The combustion kinetics of coal chars in oxygen-enriched environments.

    SciTech Connect

    Shaddix, Christopher R.; Murphy, Jeffrey J.

    2004-09-01

    Oxygen-enhanced and oxygen-fired pulverized coal combustion is actively being investigated to achieve emission reductions and reductions in flue gas cleanup costs, as well as for coal-bed methane and enhanced oil recovery applications. To fully understand the results of pilot scale tests and to accurately predict scale-up performance through CFD modeling, accurate rate expressions are needed to describe coal char combustion under these unconventional combustion conditions. In the work reported here, the combustion rates of two pulverized coal chars have been measured in both conventional and oxygen-enriched atmospheres. A combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometry diagnostic and a rapid-quench sampling probe has been used for this investigation. Highvale subbituminous coal and a high-volatile eastern United States bituminous coal have been investigated, over oxygen concentrations ranging from 6 to 36 mol% and gas temperatures of 1320-1800 K. The results from these experiments demonstrate that pulverized coal char particles burn under increasing kinetic control in elevated oxygen environments, despite their higher burning rates in these environments. Empirical fits to the data have been successfully performed over the entire range of oxygen concentrations using a single-film oxidation model. Both a simple nth-order Arrhenius expression and an nth-order Langmuir-Hinshelwood kinetic equation provide good fits to the data. Local fits of the nth-order Arrhenius expression to the oxygen-enriched and oxygen-depleted data produce lower residuals in comparison to fits of the entire dataset. These fits demonstrate that the apparent reaction order varies from 0.1 under near-diffusion-limit oxygen-depleted conditions to 0.5 under oxygen-enriched conditions. Burnout predictions show good agreement with measurements. Predicted char particle temperatures tend to be low for combustion in oxygen-depleted environments.

  13. Experimental and numerical study of PC combustion with oxygen enrichment in a blowpipe model of blast furnace

    SciTech Connect

    Cang Daqiang; Yang Min; Ding Yulong; Yang Tianjun [Univ. of Science and Technology, Beijing (China)

    1994-12-31

    The method of pulverized coal injection (PCI), oxygen enrichment position, and PC size with oxygen enrichment have been studied to improve of the combustion efficiency of PC by using a theoretical model and experiment. The results showed: (1) by using double coal lance instead of single coal lance in a blowpipe, the combustion efficiency of anthracite can be increased significantly; (2) under the experimental conditions, pure oxygen directly mixed with hot blast is suitable for combustion efficiency when oxygen content is lower then 24%, and when oxygen content is higher, oxygen enrichment location at a proper position of blowpipe away from PC lance should be used; and (3) fine anthracite particle with high oxygen content is an effective way to improve the combustion efficiency of anthracite.

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

    SciTech Connect

    Poola, R.B.; Sekar, R.; Ng, H.K. [Argonne National Lab., IL (United States); Baudino, J.H. [Autoresearch Labs., Inc., Chicago, IL (United States); Colucci, C.P. [National Renewable Energy Lab., Golden, CO (United States)

    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.

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

    NASA Astrophysics Data System (ADS)

    He, Li; Li, Dan; Wang, Kun; Suresh, Akkihebbal K.; Bellare, Jayesh; Sridhar, Tam; Wang, Huanting

    2011-12-01

    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.

  16. Effects of EGR, water/N2/CO2 injection and oxygen enrichment on the availability destroyed due to combustion for a range of conditions and fuels 

    E-print Network

    Sivadas, Hari Shanker

    2009-06-02

    This study was directed at examining the effects of exhaust gas recirculation (EGR), water/N2/CO2 injections and oxygen enrichment on availability destroyed because of combustion in simple systems like those of constant pressure and constant volume...

  17. Laser ablation ignition of premixed methane and oxygen-enriched air mixtures using a tantalum target.

    PubMed

    Li, Xiaohui; Yu, Xin; Fan, Rongwei; Yu, Yang; Liu, Chang; Chen, Deying

    2014-01-01

    We report the laser ablation ignition of premixed methane and oxygen-enriched air mixtures using a tantalum target. The minimum laser pulse energy (MPE) of the ablation ignition was obtained as 2-4 mJ, which was reduced by one order of magnitude compared with that of the direct laser-induced gas breakdown ignition. The ignition time of the ablation ignition was investigated for the first time, to our best knowledge, by measuring the emission signal profiles due to the successfully ignited flames, and an ignition time as short as ~50 ?s was obtained. The reduction in MPE will promote the miniaturization and, thus, the practical applications of laser ignition systems. PMID:24365842

  18. Potential benefits of oxygen-enriched intake air in a vehicle powered by a spark-ignition engine

    SciTech Connect

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

    1994-04-01

    A production vehicle powered by a spark-ignition engine (3.1-L Chevrolet Lumina, model year 1990) was tested. The test used oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine (1) if the vehicle would run without difficulties and (2) if emissions benefits would result. Standard Federal Test Procedure (FTP) emissions test cycles were run satisfactorily. Test results of catalytic converter-out emissions (emissions out of the converter) showed that both carbon monoxide and hydrocarbons were reduced significantly in all three phases of the emissions test cycle. Test results of engine-out emissions (emissions straight out of the engine, with the converter removed) showed that carbon monoxide was significantly reduced in the cold phase. All emission test results were compared with those for normal air (21% oxygen). The catalytic converter also had an improved carbon monoxide conversion efficiency under the oxygen-enriched-air conditions. Detailed results of hydrocarbon speciation indicated large reductions in 1,3-butadiene, formaldehyde, acetaldehyde, and benzene from the engine with the oxygen-enriched air. Catalytic converter-out ozone was reduced by 60% with 25%-oxygen-content air. Although NO{sub x} emissions increased significantly, both for engine-out and catalytic converter-out emissions, we anticipate that they can be ameliorated in the near future with new control technologies. The automotive industry currently is developing exhaust-gas control technologies for an oxidizing environment; these technologies should reduce NO{sub x} emissions more efficiently in vehicles that use oxygen-enriched intake air. On the basis of estimates made from current data, several production vehicles that had low NO{sub x} emissions could meet the 2004 Tier II emissions standards with 25%-oxygen-content air.

  19. Potential benefits of oxygen-enriched intake air in a vehicle powered by a spark-ignition engine

    NASA Astrophysics Data System (ADS)

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

    1994-04-01

    A production vehicle powered by a spark-ignition engine (3.1-L Chevrolet Lumina, model year 1990) was tested. The test used oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine (1) if the vehicle would run without difficulties and (2) if emissions benefits would result. Standard Federal Test Procedure (FTP) emissions test cycles were run satisfactorily. Test results of catalytic converter-out emissions (emissions out of the converter) showed that both carbon monoxide and hydrocarbons were reduced significantly in all three phases of the emissions test cycle. Test results of engine-out emissions (emissions straight out of the engine, with the converter removed) showed that carbon monoxide was significantly reduced in the cold phase. All emission test results were compared with those for normal air (21% oxygen). The catalytic converter also had an improved carbon monoxide conversion efficiency under the oxygen-enriched-air conditions. Detailed results of hydrocarbon speciation indicated large reductions in 1,3-butadiene, formaldehyde, acetaldehyde, and benzene from the engine with the oxygen-enriched air. Catalytic converter-out ozone was reduced by 60% with 25%-oxygen-content air. Although NO(x) emissions increased significantly, both for engine-out and catalytic converter-out emissions, we anticipate that they can be ameliorated in the near future with new control technologies. The automotive industry currently is developing exhaust-gas control technologies for an oxidizing environment; these technologies should reduce NO(x) emissions more efficiently in vehicles that use oxygen-enriched intake air. On the basis of estimates made from current data, several production vehicles that had low NO(x) emissions could meet the 2004 Tier 2 emissions standards with 25%-oxygen-content air.

  20. Oxygen-enriched diesel engine performance; A comparison of analytical and experimental results

    Microsoft Academic Search

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

    1991-01-01

    Use of oxygen-enriched combustion air in diesel can lead to significant improvements in power density, as well as reduction in particulate emissions, but at the expense of higher NOâ 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

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

    Microsoft Academic Search

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

    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 NOâ 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

  2. OXYGEN-ENRICHED COAL COMBUSTION WITH CARBON DIOXIDE RECYCLE AND RECOVERY: SIMULATION AND EXPERIMENTAL STUDY

    SciTech Connect

    John M. Veranth; Gautham Krishnamoorthy

    2001-04-01

    This report examines coal combustion using oxygen feed with carbon dioxide recycle to control the adiabatic flame temperature. Computer simulations using an existing state-of-the-art 3-dimensional computer code for turbulent reacting flows with reacting particles were employed to study the effects of increased carbon dioxide mole fraction on the char burnout, radiant heat transfer, metal partitioning, and NOx formation.

  3. OXYGEN-ENRICHED COAL COMBUSTION WITH CARBON DIOXIDE RECYCLE AND RECOVERY: SIMULATION AND EXPERIMENTAL STUDY

    SciTech Connect

    John M. Veranth; Gautham Krishnamoorthy

    2002-01-01

    An accurate estimation of the CO/CO{sub 2} ratio at the surface of an ash inclusion in coal during combustion is necessary to predict the equilibrium partial pressure of volatile reduced metal species inside the burning particle and the rate of vaporization of metal oxides. Assumptions that have been made previously for the CO/CO{sub 2} ratio at the surface of mineral inclusions are compared to those obtained from a steady state detailed kinetics code for a single porous particle (SKIPPY). The detailed kinetic simulations from SKIPPY for varying particle sizes and bulk gas compositions were used to develop algebraic expressions for the CO/CO{sub 2} ratio that can be incorporated into metal vaporization sub-models run as a post processor to detailed furnace simulations.

  4. OXYGEN-ENRICHED COAL COMBUSTION WITH CARBON DIOXIDE RECYCLE AND RECOVERY: SIMULATION AND EXPERIMENTAL STUDY

    SciTech Connect

    John M. Veranth; Gautham Krishnamoorthy

    2002-02-28

    Two computational problems were worked on for this study. The first chapter examines the option of coal combustion using oxygen feed with carbon dioxide recycle to control the adiabatic flame temperature. Computer simulations using an existing state-of-the-art 3-dimensional computer code for turbulent reacting flows with reacting particles were employed to study the effects of increased carbon dioxide mole fraction on the char burnout, radiant heat transfer, metal partitioning, and NOx formation. The second chapter compares assumptions for the CO/CO{sub 2} ratio at the surface of mineral inclusions made in previous studies to predictions obtained from a pseudo-steady state kinetic model (SKIPPY) for a single porous particle. The detailed kinetic simulations from SKIPPY for varying particle sizes and bulk gas compositions were used to develop algebraic expressions for the CO/CO{sub 2} ratio that can be incorporated into metal vaporization sub-models run as a post processor to detailed furnace simulations. Vaporization rate controls the formation of metal-enriched sub-micron particles in pulverized coal fired power plants.

  5. 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 Bloom baffle burner at GTI. The results are positive and confirm that oxygen-enriched combustion can be carried out without producing higher levels of NOx than normal air firing, if lancing of combustion air is used and the excess air levels are controlled. A simple economic study shows that the membrane processes can produce O{sub 2} at less than $40/ton EPO{sub 2} and an energy cost of 1.1-1.5 MMBtu/ton EPO{sub 2}, which are very favorable compared with conventional technologies such as cryogenics and vacuum pressure swing adsorption processes. The benefits of integrated membrane processes/combustion process trains have been evaluated, and show good savings in process costs and energy consumption, as well as reduced CO{sub 2} emissions. For example, if air containing 30% oxygen is used in natural gas furnaces, the net natural gas savings are an estimated 18% at a burner temperature of 2,500 F, and 32% at a burner temperature of 3,000 F. With a 20% market penetration of membrane-based oxygen-enriched combustion in all combustion processes by 2020, the energy savings would be 414-736 TBtu/y in the U.S. The comparable net cost savings are estimated at $1.2-2.1 billion per year by 2020, calculated as the value of fuel savings subtracted from the cost of oxygen production. The fuel savings of 18%-32% by the membrane/oxygen-enriched combustion corresponds to an 18%-32% reduction in CO{sub 2} emissions, or 23-40 MM ton/y less CO{sub 2} from natural gas-fired furnaces by 2020. In summary, results from this project (Concept Definition phase) are highly promising and clearly demonstrate that membrane processes can produce oxygen-enriched air in a low cost manner that will lower operating costs and energy consumption in industrial combustion processes. Future work will focus on proof-of-concept bench-scale demonstration in the laboratory.

  6. Experimental and analytical study to model temperature profiles and stoichiometry in oxygen-enriched in-situ combustion 

    E-print Network

    Rodriguez, Jose Ramon

    2004-09-30

    A new combustion zone analytical model has been developed in which the combustion front temperature may be calculated. The model describes in the combustion zone, the amount of fuel burned based on reaction kinetics, the fuel concentration...

  7. 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.

  8. Experimental and analytical study to model temperature profiles and stoichiometry in oxygen-enriched in-situ combustion

    E-print Network

    Rodriguez, Jose Ramon

    2004-09-30

    in Venezuela. These runs were carried out with air containing three values of oxygen concentration, 21%, 30%, and 40%. The weight percentage of sand, clay, water, and oil in the sand mix was kept constant in all runs at 86.6%, 4.7%, 4.0%, and 4.7% respectively...

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

    DOEpatents

    Poola, Ramesh B. (Woodridge, IL); Sekar, Ramanujam R. (Naperville, IL); Cole, Roger L. (Elmhurst, IL)

    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.

  10. How to cope with your sulfur problems. [COPE process; use of oxygen enriched air to increase capacity

    Microsoft Academic Search

    B. G. Goar; W. P. Hegarty; T. W. Thew

    1986-01-01

    COPE (Claus Oxygen-based Process Expansion) technology presents an improvement to the modified Claus process that replaces air with up to 100% oxygen to debottleneck Claus Sulphur Recovery Unit's (SRU's). The major equipment requirements of the COPE process are the installation of an acid gas recycle blower and a proprietary burner. The recycle stream acts as a coolant to moderate reaction

  11. Fuel preheat as NOx abatement strategy for oxygen enriched turbulent diffusion flames

    SciTech Connect

    Amin, E.M.; Pourkashanian, M.; Richardson, A.P.; Williams, A. [Univ. of Leeds (United Kingdom); Yap, L.T. [BOC Group Technical Center, Murray Hill, NJ (United States); Yetter, R.A. [Princeton Univ., NJ (United States); Moussa, N.A. [BlazeTech Corp., Cambridge, MA (United States)

    1995-12-31

    The high thermal efficiencies achievable in industrial furnaces through oxygen enrichment has attracted much interest. As a result, oxygen-enrichment techniques are used in various processes such as glass melting, ferrous as well as non-ferrous melting, cement production, lime production, etc. With the higher temperatures and the availability of oxygen, generally increased emissions of NOx have to be tolerated. In this study measurements in a laboratory scale oxygen enriched turbulent diffusion flames of preheated methane are presented. An axisymmetric burner with coflowing oxygen enriched air is used which employs direct electrical heating of the methane. Experimental techniques included the measurement of the radiant fluxes from the flame using pyrometry, on-line gas analysis for combustion products and a laser extinction technique for the measurement of soot concentration. The flow field was computed using the {kappa}-{epsilon} model with two step global reaction scheme. A simplified mechanistic model for soot formation is used. The model for soot and thermal No was based on the laminar flamelet model. The fluctuations in the mixture fraction was a clipped Gaussian pdf. Results have shown that fuel preheating can locally reduce the temperature through enhanced soot formation. The result is a reduction in the EINOx emission as a result of reduced thermal NO formation.

  12. 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. (Argonne National Lab., IL (USA)); Schaus, J.E. (Autoresearch Labs., Inc. (USA))

    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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

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

    SciTech Connect

    none,

    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.

  18. Development and demonstration of a spiral-wound thin-film composite membrane system for the economical production of oxygen-enriched air, Phase IV. Final report, January 1, 1983-December 31, 1984

    SciTech Connect

    Haesloop, D.G.; Swedo, R.J.; Burnett, L.J.

    1985-01-15

    Literature searches identified poly (vinyl isobutyl ether) as the most promising candidate barrier material for oxygen enrichment membranes. A membrane with an oxygen/nitrogen selectivity of 6.2 and a stability at 60/sup 0/C was developed. However, this membrane is fragile. Membranes using poly (2-hexyne) and poly (6-methyl-2-heptyne) were also made. (DLC)

  19. Low NOx combustion using cogenerated oxygen and nitrogen streams

    DOEpatents

    Kobayashi, Hisashi (Putnam Valley, NY); Bool, Lawrence E. (East Aurora, NY); Snyder, William J. (Ossining, NY)

    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.

  20. Centrifugal air precleaner for internal combustion engines

    Microsoft Academic Search

    1977-01-01

    An air precleaner for internal combustion engines having a central conduit for conducting precleaned air to the air intake of the engine is described. A housing is disposed around the central conduit and forms an air intake opening, an arcuate wall spaced radially outwardly from the conduit and substantially concentric therewith for conducting the incoming air stream from the intake

  1. 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.

  2. 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.

  3. 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.

  4. Early Gaseous Oxygen Enrichment to Enhance Magnetite Pellet Oxidation

    NASA Astrophysics Data System (ADS)

    Tang, Ming; Cho, Hyeon Jeong; Pistorius, Petrus Christiaan

    2014-08-01

    It is suggested that oxygen enrichment in the gas atmosphere, during continuous heating of magnetite pellets, can cause pellets to be oxidized throughout their volumes, eliminating unoxidized cores. The peculiarities of the oxidation kinetics of magnetite concentrate imply that such oxygen enrichment might be particularly effective at lower temperatures. This suggestion was tested by developing and testing a mixed-control model for pellet oxidation (to allow the sizes of unreacted cores to be predicted), and by experimentally testing the effects of oxygen enrichment at relatively low temperatures ("early oxygen enrichment"). The results confirmed that the extents (depth) of oxidation and pellet strength were both improved significantly by applying oxygen enrichment up to 873 K (600 °C), as part of a heating cycle up to 1073 K (800 °C).

  5. NISTIR 6458 Characterization of the Inlet Combustion Air in

    E-print Network

    Magee, Joseph W.

    NISTIR 6458 Characterization of the Inlet Combustion Air in NIST's Reference Spray Combustion January 2000 #12;ii Contents page Introduction 1 Reference Spray Combustion Facility 3 Numerical;1 Characterization of the Inlet Combustion Air in NIST's Reference Spray Combustion Facility: Effect of Vane Angle

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

    Microsoft Academic Search

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

    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

  7. Combustion Air Preheat Should Be More Than Simply Recycling Energy 

    E-print Network

    Grantom, R. L.

    1980-01-01

    Combustion air preheat can and should result in fuel savings far in excess of the energy added to the combustion air. In a typical installation of air preheat on a fired tubular reactor, the addition of 2.5 million BTU/hr to the combustion air...

  8. Combination of supercritical wet combustion and compressed air energy storage

    Microsoft Academic Search

    1986-01-01

    A combination of pressurized combustion and compressed air energy storage is described in which air is compressed to combustion pressure by means of a compression train comprising a plurality of stages, combustion heat is transferred at combustion pressure to boiling feedwater, cooled flue gas is reheated and expanded through turbines which drive the compressor stages, the compression train having capacity

  9. 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...

  10. Internal combustion engine with compound air compression

    SciTech Connect

    Paul, M.A.; Paul, A.

    1991-10-15

    This patent describes an internal combustion engine in combination with a compound air compression system. It comprises: a reciprocator with at least one cylinder, at least one piston reciprocal in the cylinder and a combustion chamber formed in substantial part by portions of the piston and cylinder, the reciprocator having a drive shaft; a rotary compressor having a drive shaft mechanically coupled to the drive shaft of the reciprocator, the rotary compressor having a Wankel-type, three-lobe, epitrochiodal configuration sides having a conduit conjected to the reciprocator for supplying compressed air to the reciprocator; a turbocharged with a gas turbine and a turbocompressor, the turbocompressor having an air conduit connected to the expander side of the rotary compressor; and a bypass conduit with a valve means connecting the turbocharger to the reciprocator for supplying compressed air directly to the reciprocator wherein the drive shaft of the reciprocator and the drive shaft of the compressor have connecting means for transmitting mechanical energy to the reciprocator at mid to high operating speeds of the engine when the turbocharge supplies compressed air to the rotary compressor and, at least in part, drives the rotary compressor.

  11. Effect of air distribution on solid fuel bed combustion

    SciTech Connect

    Kuo, J.T.; Hsu, W.S.; Yo, T.C. [National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering

    1996-09-01

    One important aspect of refuse mass-burn combination control is the manipulation of combustion air. Proper air manipulation is key to the achievement of good combustion efficiency and reduction of pollutant emissions. Experiments, using a small fix-grate laboratory furnace with cylindrical combustion chamber, were performed to investigate the influence of undergrate/sidewall air distribution on the combustion of beds of wood cubes. Wood cubes were used as a convenient laboratory surrogate of solid refuse. Specifically, for different bed configurations (e.g. bed height, bed voidage and bed fuel size, etc.), burning rates and combustion temperatures at different bed locations were measured under various air supply and distribution conditions. One of the significant results of the experimental investigation is that combustion, with air injected from side walls and no undergrate air, provide the most efficient combustion. On the other hand, combustion with undergrate air achieves higher combustion rates but with higher CO emissions. A simple one-dimensional model was constructed to derive correlations of combustion rate as functions of flue gas temperature and oxygen concentration. Despite the fact that the model is one dimensional and many detailed chemical and physical processes of combustion are not considered, comparisons of the model predictions and the experimental results indicate that the model is appropriate for quantitative evaluation of bed burning rates.

  12. Spark-ignition, air-compressing, internal combustion engine

    Microsoft Academic Search

    F. Chmela; W. Herzog; R. Meier

    1988-01-01

    This patent describes a spark-ignition, air-compressing, internal combustion engine that has direct ignition of a major portion of the fuel by means of a jet onto the wall of the combustion chamber that is provided, in the shape of a body of revolution, in the piston, whereby rotary motion is imparted by means known per se to the inflowing air

  13. Oxygen Enrichment in the Process and Chemical Industries

    E-print Network

    Milne, R. T.

    1984-01-01

    cal was the di scovery in the early 1900's that air, which contains 21% oxygen by volume, could be liquefied by means of the Joule-Thomson cooling effect which results when a compressed gas is expanded through a restricting orifice. The liquefied... an eleva tion of the adiabatic flame temperature (Figure 3), which leads to improved heat transfer in the combustion zone. This results in a number of potential advantages: i. Fuel Savings At constant output the fuel firing rate may be reduced...

  14. Spark-ignition, air-compressing, internal combustion engine

    SciTech Connect

    Chmela, F.; Herzog, W.; Meier, R.

    1988-09-20

    This patent describes a spark-ignition, air-compressing, internal combustion engine that has direct ignition of a major portion of the fuel by means of a jet onto the wall of the combustion chamber that is provided, in the shape of a body of revolution, in the piston, whereby rotary motion is imparted by means known per se to the inflowing air in the direction of the injected fuel jet so as to cause the fuel to be removed gradually in the vapor state from the wall of the combustion chamber and to be mixed with the air, the injection nozzle being located in the cylinder head near the combustion chamber rim, with the spark plug, which is disposed opposite the injection nozzle, extending into the combustion chamber in the top dead center position of the piston, with the side wall of the combustion chamber, when viewed in cross section, being formed by two arcs that blend into each other and have respective radii of curvature R/sub 1/, R/sub 2/, the first arc having a radius R/sub 1/ that extends from a restricted combustion chamber opening down to the maximum combustion chamber diameter D/sub B/, and the second arc having a radius R/sub 2/ that extends down to the bottom of the combustion chamber and blends into the latter. The maximum combustion chamber diameter D/sub B/ being 0.5 to 0.7 times the diameter D/sub K/ of the piston and being at a defined depth t/sub D/ from the piston crown relative to the depth T/sub B/ of the combustion chamber, the ratio of the diameter d/sub H/ of the combustion chamber opening to the maximum combustion chamber diameter D/sub B/.

  15. Understanding Air: Climate Change and Modeling Combustion with LEGO® Bricks

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2012-06-15

    In this lesson, students learn about the components of air and the chemical reactions that release carbon dioxide into the atmosphere. They model combustion using LEGO bricks, and explore the connection between carbon dioxide, climate change, and environmental health.

  16. Not adiabatic temperature of combustion gas-air mixture

    NASA Astrophysics Data System (ADS)

    Iovleva, O. V.

    2015-06-01

    In the present work was carried out thermodynamic analysis, the purpose of which was to determine the formula for calculating the temperature of combustion gas-air mixture in non-adiabatic conditions.

  17. Model Test on Underground Coal Gasification (UCG) with Low-pressure Fire Seepage Push-through. Part II: Oxygen-enriched Fire Seepage and Analysis

    Microsoft Academic Search

    L. H. Yang

    2008-01-01

    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

  18. 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.

  19. Combustion Air Preheat Should Be More Than Simply Recycling Energy

    E-print Network

    Grantom, R. L.

    1980-01-01

    results in a fuel savings of 6.8 million BTU/hr. Control of excess effects of excess combustion air on radiant heat transfer in a fired tubular reactor, the point at which air preheat does become simply recycling energy, and the point at which any...

  20. BIBLIOGRAPHY ON INTERNAL COMBUSTION ENGINES 1. F. Obert, Internal Combustion Engines and Air Pollution, Intext Educational Publishers, 1973

    E-print Network

    Goldwasser, Shafi

    BIBLIOGRAPHY ON INTERNAL COMBUSTION ENGINES 1. F. Obert, Internal Combustion Engines and Air, The Internal Combustion Engine, International Textbook Company, 1961. (A basic text now out of print and somewhat dated.) 3. C.F. Taylor, The Internal Combustion Engine in Theory and Practice. Volumes I and II, M

  1. Removal of trichlorobenzene using 'oxygen-enriched' highly active absorbent.

    PubMed

    Zhao, Yi; He, Peng; Zhang, Yu-Hai; Ma, Shuangchen

    2011-01-01

    Fly ash, industry lime and an additive, Ca(ClO2)2 (C) were used to prepare the 'oxygen-enriched' highly active absorbent (HAA). The influencing factors for removal of 1,2,4-trichlorobenzene (TCB) using this absorbent such as reaction temperature, simulating gas flow rate, oxygen content, etc. were studied in a self-designed reactor. The optimum experimental conditions of removing 1,2,4-TCB are that the content of an oxidizing additive in the absorbent is 3% (wt), simulating gas flow rate is 100 mL/min, reaction temperature is 250 degrees C, and the content of oxygen in simulating gas is 6%. The maximum removal efficiency is 81.71% in 10 mins. The absorption capacity of the absorbent is 0.000111 g/g. The reaction products were determined by gas chromatograph/mass spectrometer (GC/ MS), 2,6-Bis-[1,1-Dimethylethyl]-4-methyl-Phenol is considered to be the major intermediate product. The reaction route was revealed. PMID:21473266

  2. INCREASED EFFICIENCY IN HEATING: STATE-OF-THE-ART OXYFUEL COMBUSTION

    Microsoft Academic Search

    Tommi Niemi

    Increased throughput and flexibility, reduced fuel consumption and decreased emissions of greenhouse gases are the main reasons the use of oxyfuel based melting and heating become increasingly popular. In the middle of the 1980s AGA began to equip the first furnaces with oxygen-enrichment systems. These systems increased the oxygen content of the combustion air to 23-24%. In 1990 AGA converted

  3. Catalytic Igniter to Support Combustion of Ethanol-Water\\/Air Mixtures in Internal Combustion Engines

    Microsoft Academic Search

    Dan Cordon; Eric Clarke; Steven Beyerlein; Judi Steciak

    Lean ethanol-water\\/air mixtures have potential for reducing NOx and CO emissions in internal combustion engines. Igniting such mixtures is not possible with conventional ignition sources. An improved catalytic ignition source is being developed to aid in the combustion of aqueous ethanol. The operating principle is homogeneous charge compression ignition in a catalytic pre-chamber, followed by torch ignition of the main

  4. COMBUSTION CONTROL OF TRACE ORGANIC AIR POLLUTANTS FROM MUNICIPAL WASTE COMBUSTORS

    EPA Science Inventory

    The US Environmental Protection Agency (EPA) is considering the use of combustion techniques for controlling air emissions of chlorinated dioxins, chlorinated furans, and other trace organics from municipal waste combustion (MWC) facilities. Recommendations for good combustion pr...

  5. Closed loop air cooling system for combustion turbines

    DOEpatents

    Huber, David John (North Canton, OH); Briesch, Michael Scot (Orlando, FL)

    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.

  6. Oxygen Enrichment in the Process and Chemical Industries 

    E-print Network

    Milne, R. T.

    1984-01-01

    an air oxidation step (Table 1). Some Organic Intermediates Produced by Air Oxidation: ? Adipic Acid ? Acetaldehyde ? Acetic Acid ? Acrylonitrile ? Acrylic Acid ? Acetone ? Ethylene Oxide ? Formaldehyde ? Maleic Anhydride ? Phenol...

  7. 75 FR 80761 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ...Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines AGENCY: Environmental Protection Agency (EPA...standards for hazardous air pollutants for reciprocating internal combustion engines and requesting public comment on one issue...

  8. Effect of Combustion Air Preheat on a Forged Furnace Productivity 

    E-print Network

    Ward, M. E.; Bohn, J.; Davis, S. R.; Knowles, D.

    1984-01-01

    A basic thermal analysis of a gas fired forge furnace can determine the fuel savings from exhaust energy recovery/combustion air preheat on a furnace operating at a single condition, for example, high fire. What this analysis is not able...

  9. Combustion Air Preheat on Steam Cracker Furnaces 

    E-print Network

    Kenney, W. F.

    1983-01-01

    Beginning in 1978, Exxon has started up nine large new steam cracking furnaces with various levels of air preheat, and has seven more under construction. Sources of heat have included process streams, flue gas and gas turbine exhaust. Several...

  10. Combustion Air Preheat on Steam Cracker Furnaces

    E-print Network

    Kenney, W. F.

    1983-01-01

    aspects of the technology employed have been patented in the U.S. and elsewhere. This paper discusses the use of process heat and gas turbine exhaust for air preheat to provide plant fuel savings of about 8% over and above a modern, fuel efficient...

  11. Secondary air supply control apparatus for internal combustion engine

    SciTech Connect

    Miura, M.

    1981-01-20

    A secondary air supply control apparatus for an internal combustion engine comprises an air pump for producing the secondary air flow, a secondary air supply passage leading to an exhaust system of the engine, a bypass passage leading to the atmosphere, and a valve element connected to a diaphragm. The diaphragm constitutes one wall of a pressure chamber which is supplied with a negative intake pressure prevailing in an intake system of the engine, so as to move the valve element to a position at which the secondary air flow is directed to the secondary air supply passage when the negative intake pressure is higher than a predetermined level. There is provided a control unit operable in response to the pressure of the secondary air flow supplied to the exhaust system to apply the atmospheric pressure to the pressure chamber, thereby moving the valve element to another position at which the secondary air flow is directed to the bypass passage when the pressure of the secondary air flow supplied to the exhaust system is increased beyond a level which imposes overload on the air pump.

  12. Internal combustion engine air intake system with variable effective length

    SciTech Connect

    Wada, H.; Horio, K.; Abe, K.

    1988-04-19

    An air intake system for feeding intake air to combustion chambers of a multicylinder internal combustion engine having two groups of longitudinally spaced engine cylinders is described comprising: a. a longitudinally extending surge tank positioned adjacent the engine cylinders; b. flow control valve means for opening and closing the aperture, the flow control valve means including a butterfly valve pivotally mounted in the aperture of the wall extension of the extension portion; and c. actuator means responsive to engine operating conditions for controlling opening and closing of the butterfly valve to vary the extent of flow communication between the volumetric chambers through the aperture, thereby varying the effective length of the intake system with engine operating conditions.

  13. Hybrid Robust Air-Path Control for Diesel Engines Operating Conventional and Low Temperature Combustion Modes

    Microsoft Academic Search

    Junmin Wang

    2008-01-01

    This paper describes a hybrid robust nonlinear control approach for modern diesel engines operating multiple combustion modes; in particular, low temperature combustion and conventional diesel combustion modes. An innovative control system is designed to track different key engine air-path operating variables at different combustion modes as well as to avoid singularity which is inherent for turbocharged diesel engine running multiple

  14. 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.

  15. 78 FR 14457 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ...National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines Correction In rule document 2013-01288, appearing on pages...

  16. Research in Industrial Combustion Systems - Current and Future R&D 

    E-print Network

    Rebello, W. J.; Keller, J. G.

    1987-01-01

    This paper briefly describes the current R&D activity in industrial combustion systems. The areas covered are novel burner systems, oxygen enriched systems, combustion controls and sensors and unique industrial process modifications. Some...

  17. 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.

  18. Combustion of stratified hydrogen-air mixtures in the 10.7 m 3 combustion test facility cylinder

    Microsoft Academic Search

    D. R. Whitehouse; D. R. Greig; G. W. Koroll

    1996-01-01

    This paper presents preliminary results from hydrogen concentration gradient combustion experiments in a 10.7 m3 cylinder. These gradients, also referred to as stratified mixtures, were formed from dry mixtures of hydrogen and air at atmospheric temperature. Combustion pressures, burn fractions and flame speeds in concentration gradients were compared with combustion of well-mixed gases containing equivalent amounts of hydrogen. The studied

  19. Experimental investigation on plasma-assisted combustion characteristics of premixed propane/air mixture

    NASA Astrophysics Data System (ADS)

    Liu, Xingjian; He, Liming; Yu, Jinlu; Zeng, Hao; Jin, Tao

    2015-06-01

    A detailed study on the plasma-assisted combustion (PAC) characteristics of premixed propane/air mixture is presented. The PAC is measured electrically, as well as optically with a multichannel spectrometer. The characteristics are demonstrated by stable combustion temperature and combustion stability limits, and the results are compared with conventional combustion (CC). Stable combustion temperature measurements show that the introduction of PAC into combustion system can increase the stable combustion temperature, and the increment is more notable with an increase of discharge voltage. Besides, the rich and weak limits of combustion stability are both enlarged when plasma is applied into the combustion process and the increase of discharge voltage results in the expansion of combustion stability limits as well. The measurements of temperature head and emission spectrum illustrate that the kinetic enhancement caused by reactive species in plasma is the main enhancement pathway for current combustion system.

  20. The Effect of Intraoral Suction on Oxygen-Enriched Surgical Environments: A Mechanism for Reducing the Risk of Surgical Fires

    PubMed Central

    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

  1. Soot and NO formation in methane–oxygen enriched diffusion flames

    Microsoft Academic Search

    A. BELTRAME; P. PORSHNEV; W. MERCHAN-MERCHAN; A. SAVELIEV; A. FRIDMAN; L. A. KENNEDY; O. PETROVA; S. ZHDANOK; F. AMOURI; O. CHARON

    2001-01-01

    NO and soot formation were investigated both numerically and experimentally in oxygen-enriched counterflow diffusion flames. Two sets of experiments were conducted. In the first set, the soot volume fraction was measured as a function of oxygen content in the oxidizer jet at constant strain rate (20 s?1). In the second set of experiments, the soot volume fraction was measured as

  2. 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...

  3. Numerical Prediction of Waste Bed Combustion in Municipal Solid Waste Incinerator

    NASA Astrophysics Data System (ADS)

    Yasuda, Toshihiko; Shigemasa, Sachiko; Furubayashi, Michitaka; Tomiyama, Shigeo

    A new CFD-code "3d-MSW" to predict the waste bed combustion in the stoker-type Municipal Solid Waste Incinerators (MSWI) was developed. 3d-MSW was validated by comparison with the combustion tests in a pilot incinerator. The calculation results could predict the waste bed combustion under not only normal air but also oxygen enrichment air. Grate feeding velocity in an actual incinerator was also evaluated by applying the new code. 3d-MSW could present the influence of the grate feeding velocity on gas temperature and carbon monoxide concentration. 3d-MSW is very useful as a prediction tool for understanding the phenomenon of the waste bed combustion in the stoker-type MSWI.

  4. 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.

  5. 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.

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

    SciTech Connect

    Weidong Fan; Zhengchun Lin; Youyi Li; Jinguo Kuang; Mingchuan Zhang [Shanghai Jiao Tong University, Shanghai (China). School of Mechanical & Power Engineering

    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.

  7. Computer simulation of pulverized coal combustion in various COâ\\/Oâ atmospheres and in air

    Microsoft Academic Search

    G. F. Berry; C. S. Wang; K. C. Chang; A. M. Wolsky

    1987-01-01

    In this study, the authors used a one-dimensional coal combustion or gasification (1-DICOG) computer code to simulate differences in the combustion performance of pulverized coal when various COâ\\/Oâ mixtures were substituted for air in the combustion process. Four test cases were analyzed, and results predicted by the model were compared with the corresponding results of actual combustion experiments. Comparisons of

  8. Computer simulation of pulverized coal combustion in various COâ\\/Oâ atmospheres and in air

    Microsoft Academic Search

    G. F. Berry; C. S. Wang; K. C. Chang; A. M. Wolsky

    1986-01-01

    In this study, we used a one-dimensional coal combustion or gasification (1-DICOG) computer code to simulate differences in the combustion performance of pulverized coal when various COâ\\/Oâ mixtures were substituted for air in the combustion process. Four test cases were analyzed, and results predicted by the model were compared with the corresponding results of actual combustion experiments. Comparisons of predicted

  9. The Influence of Directed Air Flow on Combustion in Spark-Ignition Engine

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Spencer, R C

    1939-01-01

    The air movement within the cylinder of the NACA combustion apparatus was regulated by using shrouded inlet valves and by fairing the inlet passage. Rates of combustion were determined at different inlet-air velocities with the engine speed maintained constant and at different engine speeds with the inlet-air velocity maintained approximately constant. The rate of combustion increased when the engine speed was doubled without changing the inlet-air velocity; the observed increase was about the same as the increase in the rate of combustion obtained by doubling the inlet-air velocity without changing the engine speed. Certain types of directed air movement gave great improvement in the reproducibility of the explosions from cycle to cycle, provided that other variables were controlled. Directing the inlet air past the injection valve during injection increased the rate of burning.

  10. Combustion Air Preheat and Radiant Heat Transfer in Fired Heaters - A Graphical Method for Design and Operating Analysis 

    E-print Network

    Grantom, R. L.

    1981-01-01

    The installation of combustion air preheat is a widely used technique for improving the fuel efficiency of existing fired heaters and fired tubular reactors. By increasing adiabatic flame temperature, combustion air preheat increases radiant section...

  11. 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.

  12. Preliminary analysis of an improved external combustion hot air power system

    SciTech Connect

    Fineblum, S.S. [Available Energy Co., Rochester, NY (United States)

    1995-12-31

    A novel open cycle, external combustion power system is described. It is characterized by an isothermal, expansion as in classical Ericsson and Stirling cycles, by thermally enhanced combustion and by recuperation. One mechanical embodiment of the proposed hot air system is a hot air turbine power system with external combustion. Analysis predicts the variation of specific work and efficiency as a function of the compression ratio and temperature of the isothermal expansion. The basic heat transfer problem, which is characteristic of all external combustion systems, is identified and analyzed. Specific opportunities for heat transfer enhancement are described and feasibility is demonstrated.

  13. Materials for FBC (fluidized-bed combustion) air heater applications

    SciTech Connect

    Natesan, K.; Miller, S.A.; Podolski, W.F.

    1987-01-01

    The US DOE-sponsored Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) is intended to assess the performance of various heat exchanger materials in order to establish confidence in the resultant designs of fluidized-bed combustion (FBC) air heater systems. Westinghouse Electric Corp. is preparing specifications and hardware for the ACAHE. Argonne National Laboratory (ANL), through a contract with the Rocketdyne Division of Rockwell International, will conduct the tests in the DOE 6-ft by 6-ft AFBC facility in El Segundo, California. This paper presents a brief overview of the project, followed by a summary of the materials assessment work at ANL. Pertinent high-temperature materials exposure data and a possible corrosion mechanism in FBC's are discussed. Results from laboratory-scale corrosion experiments are then presented. These tests, have provided corrosion information on a variety of ASME-coded and noncoded structural materials, coatings, claddings, and weldments under a well-characterized laboratory test environment simulating the atmosphere in an FBC. 35 refs.

  14. 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.

  15. 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.

  16. 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.

  17. Air fuel ratio control apparatus and method for an internal combustion engine with a turbocharger

    SciTech Connect

    Sawamoto, K.; Ikeura, K.; Morita, T.; Yamaguchi, H.

    1984-05-29

    Normally, an air-fuel ratio is controlled in accordance with the engine speed and the intake air quantity of an internal combustion engine with a turbocharger. When the output pressure of the turbocharger increases excessively, an intake relief valve opens to decrease the intake air quantity. In this case, the fuel injection quantity is controlled solely in accordance with the engine speed.

  18. 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

  19. Estimation of Fuel Savings by Recuperation of Furnace Exhausts to Preheat Combustion Air

    E-print Network

    Rebello, W. J.; Kohnken, K. H.; Phipps, H. R., Jr.

    1980-01-01

    ESTIMATION OF FUEL SAVINGS BY RECUPERATION OF FURNACE EXHAUSTS TO PREHEAT COMBUSTION AIR Wilfred J. Rebello PAR Enterprises Inc. , Fairfax, VA Kent H. Kohnken GTE Products Corp., Towanda, PA Harold R. Phipps Jr. Systems Consultants Inc...

  20. Woodstove for heated air forced into a secondary combustion chamber and method of operating same

    SciTech Connect

    Hall, R.E.; Spolek, G.A.; Wasser, J.H.; Butts, N.L.

    1991-04-16

    This patent describes a woodstove comprising a primary combustion chamber for receiving a load of wood fuel, a secondary combustion chamber in fluid flow relation with the primary chamber, fan means for forcing air from outside the woodstove into the secondary chamber, the air from outside the woodstove forced into the secondary chamber being heated prior to entering the secondary chamber, and means for controlling the fan means in response to the temperature of gases in the secondary chamber.

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

    SciTech Connect

    Markovic, Miladin, E-mail: m.markovic@utwente.nl; 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 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 process. In this paper an experimental comparison between conventional and reversed combustion is presented.

  2. Method for controlling air\\/fuel ratio of fuel supply for an internal combustion engine

    Microsoft Academic Search

    A. Yasuoka; T. Kiuchi

    1987-01-01

    A method is described for controlling an air-fuel ratio of mixture to be supplied to an internal combustion engine having a fuel supply system, comprising the steps of: detecting whether or not an amount of the fuel to be supplied to the engine by means of the fuel supply system is greater than a reference amount; correcting the air-fuel ratio

  3. Method for controlling air\\/fuel ratio of fuel supply for an internal combustion engine

    Microsoft Academic Search

    A. Yamato; A. Fujimura

    1988-01-01

    A method is described for controlling an air\\/fuel ratio of mixture to be supplied to an internal combustion engine having a fuel supply system, comprising the steps of: detecting whether or not an amount of the fuel to be supplied to the engine by means of the fuel supply system is greater than a reference amount; correcting the air\\/fuel ratio

  4. Suppression of premixed combustion dynamics utilizing microjet air injection

    E-print Network

    Hudgins, Duane Edward

    2008-01-01

    The problem of thermoacoustic instability in continuous combustion systems is a major challenge in the field of propulsion and power generation. With the current environmental and political pressure that is being placed ...

  5. 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 [Tsinghua University, Beijing (China). Department of Thermal Engineering

    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.

  6. NO x and SO x emissions of a high sulfur self-retention coal during air-staged combustion

    Microsoft Academic Search

    Sen Li; Tongmo Xu; Peng Sun; Qulan Zhou; Houzhang Tan; Shien Hui

    2008-01-01

    NOx and SOx emissions of air-staged combustion were investigated in a 1MW tangentially-fired furnace combusting a high sulfur self-retention coal. Two variables including the air stoichiometric ratio of primary combustion zone and the relative location of over-fire air (OFA) injection ports were studied. These results suggest that NOx reduction efficiency monotonically increases with increasing the relative location of OFA injection

  7. 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.

  8. 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.

  9. Analysis of fuel vaporization, fuel/air mixing, and combustion in lean premixed/prevaporized combustors

    SciTech Connect

    Deur, J.M. [NYMA, Inc., Brook Park, OH (United States); Penko, P.F. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Cline, M.C. [Los Alamos National Lab., NM (United States)

    1995-07-01

    Requirements to reduce pollutant emissions from gas turbines used in aircraft propulsion and ground-based power generation have led to consideration of lean premixed/prevaporized (LPP) combustion concepts. This paper describes a series of the LPP combustor analyses performed with KIVA-II, a multi-dimensional CFD code for problems involving sprays, turbulence, and combustion. Modifications to KIVA-II`s boundary condition and chemistry treatments have been made to meet the needs of the present study. The study examines the relationships between fuel vaporization, fuel/air mixing, and combustion in a generic LPP combustor. Parameters considered include: mixer tube diameter, mixer tube length, mixer tube configuration (straight versus converging/diverging tubes), 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 have been 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.

  10. 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.

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

    DOEpatents

    Tuthill, Richard Sterling (Bolton, CT); Bechtel, II, William Theodore (Scotia, NY); Benoit, Jeffrey Arthur (Scotia, NY); Black, Stephen Hugh (Duanesburg, NY); Bland, Robert James (Clifton Park, NY); DeLeonardo, Guy Wayne (Scotia, NY); Meyer, Stefan Martin (Troy, NY); Taura, Joseph Charles (Clifton Park, NY); Battaglioli, John Luigi (Glenville, NY)

    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. Combustion of premixed fuel and air downstream of a plane sudden-expansion

    Microsoft Academic Search

    L. Khezzar; S. R. N. De Zilwa; J. H. Whitelaw

    1999-01-01

    Experiments have been performed to quantify the isothermal and combusting flows downstream of a plane sudden-expansion. The\\u000a detailed measurements correspond to an area expansion ratio of 2.86 and a Reynolds number of 20000, and the combusting flows\\u000a comprised premixed methane and air over a range of equivalence ratios with emphasis on values of 0.72 and 0.92 which gave\\u000a rise to

  13. Ignition and combustion of a hydrogen-air mixture in a rapid-compression combustor

    Microsoft Academic Search

    A. A. Buzukov

    1999-01-01

    In a rapid-compression combustor with a freely moving piston, the efficiency of thermomechanical conversion of energy was\\u000a determined in the detonation combustion regime of a stoichiometric hydrogen-air mixture under conditions close to those observed\\u000a during operation of a piston engine of internal combustion in the starting regime. It is shown that this regime of heat release\\u000a is characterized not only

  14. Retene-a molecular marker of wood combustion in ambient air

    Microsoft Academic Search

    Thomas Ramdahl

    1983-01-01

    The use of wood as a fuel has increased since the oil embargo in 1973. Several studies have shown that wood combustion may make a significant contribution to air pollution. Using 14C as a tracer for contemporary carbonaceous materials, 30-70% of the atmospheric carbon has been shown to originate from wood combustion in areas affected by this source1-3. Other studies

  15. Large Eddy simulation of turbulent hydrogen-fuelled supersonic combustion in an air cross-flow

    NASA Astrophysics Data System (ADS)

    Ingenito, A.; Cecere, D.; Giacomazzi, E.

    2013-09-01

    The main aim of this article is to provide a theoretical understanding of the physics of supersonic mixing and combustion. Research in advanced air-breathing propulsion systems able to push vehicles well beyond is of interest around the world. In a scramjet, the air stream flow captured by the inlet is decelerated but still maintains supersonic conditions. As the residence time is very short , the study of an efficient mixing and combustion is a key issue in the ongoing research on compressible flows. Due to experimental difficulties in measuring complex high-speed unsteady flowfields, the most convenient way to understand unsteady features of supersonic mixing and combustion is to use computational fluid dynamics. This work investigates supersonic combustion physics in the Hyshot II combustion chamber within the Large Eddy simulation framework. The resolution of this turbulent compressible reacting flow requires: (1) highly accurate non-dissipative numerical schemes to properly simulate strong gradients near shock waves and turbulent structures away from these discontinuities; (2) proper modelling of the small subgrid scales for supersonic combustion, including effects from compressibility on mixing and combustion; (3) highly detailed kinetic mechanisms (the Warnatz scheme including 9 species and 38 reactions is adopted) accounting for the formation and recombination of radicals to properly predict flame anchoring. Numerical results reveal the complex topology of the flow under investigation. The importance of baroclinic and dilatational effects on mixing and flame anchoring is evidenced. Moreover, their effects on turbulence-scale generation and the scaling law are analysed.

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

    E-print Network

    Geddes, Cameron Guy Robinson

    A New Type of Steady and Stable, Laminar, Premixed Flame in Ultra-Lean, Hydrogen-Air Combustion in the development of combustion science. Several aspects of these two-dimensional flame cells are identified for premixed combustion when the other types of idealized flames are inapplicable. 1 #12;Nomenclature fuel

  17. COMBUSTION OF AEROSOLIZED SPHERICAL ALUMINUM POWDERS AND FLAKES IN AIR

    Microsoft Academic Search

    B. Z. EAPEN; V. K. HOFFMANN; M. SCHOENITZ; E. L. DREIZIN

    2004-01-01

    Combustion rates and completeness of aerosolized spherical aluminum powders and flakes are compared using constant volume explosion experiments. The comparison of particles and flake sizes was made based on their specific surface areas determined using the Brunauer–Emmett–Teller (BET) method and respective “BET diameters.” It is observed that the rates of pressure rise and respective rates of flame propagation were higher

  18. Pressure measurements in a hydrogen combustion environment: hydrogen-air combustion test series 1 and 2 in the FITS tank. Volume 1

    Microsoft Academic Search

    Roller

    1985-01-01

    Test series 1 and 2 examined the effects of a number of parameters on hydrogen-air combustion: the initial temperature and pressure of the gases, the effect of added steam or carbon dioxide as diluents, and the percent hydrogen in air. For tests in the range of 20% to 40% hydrogen in air, recorded peak pressures were equal to adiabatic, isochoric,

  19. A comparative assessment of alternative combustion turbine inlet air cooling system

    SciTech Connect

    Brown, D.R.; Katipamula, S.; Konynenbelt, J.H.

    1996-02-01

    Interest in combustion turbine inlet air cooling (CTAC) has increased during the last few years as electric utilities face increasing demand for peak power. Inlet air cooling increases the generating capacity and decreases the heat rate of a combustion turbine during hot weather when the demand for electricity is generally the greatest. Several CTAC systems have been installed, but the general applicability of the concept and the preference for specific concepts is still being debated. Concurrently, Rocky Research of Boulder City, Nevada has been funded by the U.S. Department of Energy to conduct research on complex compound (ammoniated salt) chiller systems for low-temperature refrigeration applications.

  20. Emissions of organic hazardous air pollutants from the combustion of pulverized coal in a small-scale combustor

    Microsoft Academic Search

    C. Andrew Miller; Ravi K. Srivastava; J. V. Ryan

    1994-01-01

    The article gives results of a characterization of emissions of 76 organic hazardous air pollutants (HAPs) in flue gases from the combustion of pulverized coal in a small-scale down-fired combustor. The combustor was operated under different conditions to simulate baseline, high excess air firing, and nitrogen oxide (NOx) controls by combustion modifications. Samples were extracted near the combustor exit, upstream

  1. Combustion engine having fuel cut-off at idle speed and compressed air starting and method of operation

    Microsoft Academic Search

    Slaughter

    1988-01-01

    This patent describes a non-idle method of operating an internal combustion engine including a rotary engine shaft; fuel supply means to supply fuel to the engine to cause the operation of the engine; an air compressor driven by rotation of the shaft and communicating with the engine to supply compressed air thereto for mixing with fuel to form a combustible

  2. Comparative evaluation of gas-turbine engine combustion chamber starting and stalling characteristics for mechanical and air-injection

    NASA Technical Reports Server (NTRS)

    Dyatlov, I. N.

    1983-01-01

    The effectiveness of propellant atomization with and without air injection in the combustion chamber nozzle of a gas turbine engine is studied. Test show that the startup and burning performance of these combustion chambers can be improved by using an injection during the mechanical propellant atomization process. It is shown that the operational range of combustion chambers can be extended to poorer propellant mixtures by combined air injection mechanical atomization of the propellant.

  3. Increased diesel engine air utilization analysis: Closer to stoichiometric combustion. Final report

    SciTech Connect

    Matheaus, A.C.

    1996-09-01

    Large gains in propulsion system reduction can be achieved by moving closer to stoichiometric combustion in diesel engines. This paper is intended to identify possible fuel injection and combustion strategies to achieve higher diesel engine power density via improved air utilization. The following technology should be addressed for near-term solutions to better air utilization in diesel engines. Utilize high pressure injection equipment that has flexible rate shaping and the smallest possible injector holes. Ideally, fuel injection systems that can control split injections are needed. The appropriate combustion chamber is the quiescent chamber to match the high injection pressures and a shallow combustion bowl. It is necessary to eliminate dead-volumes by moving the top piston ring as close to the crown as possible and reducing the piston-to-cylinder head clearance. If possible, it is advisable to use flush mounted valves and eliminate valve pockets. Increased turbocharger boost would allow smaller engine packaging. Methods to control peak cylinder pressure should be considered. The most promising long-term technology is the Homogeneous Charge Compression Ignition (HCCI) combustion process. Stoichiometric combustion is possible without visible smoke. Further development of this system is necessary for this to be a viable solution.

  4. Air fraction estimation for multiple combustion mode diesel engines with dual-loop EGR systems

    Microsoft Academic Search

    Junmin Wang

    2008-01-01

    This paper describes an innovative air fraction estimation method for diesel engines with dual-loop exhaust gas recirculation (EGR) systems to conduct multiple and alternative combustion modes for engine-out emission reduction. An observer is designed to estimate the air fractions in all the engine intake\\/exhaust sections using standard sensors equipped on the engine. The observer can provide indispensable information for the

  5. Ignition and extinction of flames near surfaces: Combustion of H[sub 2] in air

    Microsoft Academic Search

    D. G. Vlachos; L. D. Schmidt; R. Aris

    1993-01-01

    The ignition and extinction characteristics in homogeneous combustion of H[sub 2] in air close to inert surfaces are studied with detailed chemistry involving 19 reversible reactions and 9 species. Flame structures for gases impinging on planar surfaces with stagnation point flow are computed using numerical bifurcation theory. Two-parameter bifurcation diagrams are constructed as functions of equivalence ratio and strain rate.

  6. 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 ...

  7. 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.

  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. 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...

  10. BATTERY POWERED PM-10 INDOOR AIR SAMPLERS APPLIED TO UNVENTED THIRD WORLD RESIDENTIAL COMBUSTION SOURCES

    EPA Science Inventory

    The paper discusses a battery-powered PM-10 indoor air sampler applied to unvented Third World residential combustion sources. (NOTE: Specialized PM-10 sampling systems have been developed and used in support of a joint U.S. EPA/People's Republic of China Institute of Environment...

  11. Control of air toxin particulate and vapor emissions after coal combustion utilizing calcium magnesium acetate

    Microsoft Academic Search

    Judith Irene Shuckerow; Judith Anne Steciak; Donald L. Wise; Yiannis A. Levendis; Girard A. Simons; Joseph D. Gresser; Edgar B. Gutoff; C. David Livengood

    1996-01-01

    Major environmental issues are now coming to the forefront in all parts of the globe with increased public awareness of the human health effects and the possible effects on our global environment. Modern control technologies, when implemented, have significantly reduced air pollution emissions that are a result of coal combustion during this century. However, the emissions have not been completely

  12. Self-Sustained Flaming Combustion and Ignition of Single Wood Pieces in Quiescent Air

    Microsoft Academic Search

    B. TUYEN; R. LOOP; S. C. BHATTACHARYA

    1995-01-01

    Single wood pieces in quiescent air were ignited by an electric coil which was removed shortly after. There was found some critical size, specimens smaller than which would be ignited, burn with a flame and, produce a carbonaceous residue (sometimes glowing). Thin pieces burned more easily than thick ones but the duration of flaming combustion depended on the specimen size.

  13. 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 process. In this paper an experimental comparison between conventional and reversed combustion is presented. PMID:24125795

  14. Combustion Gas Turbine Power Enhancement by Refrigeration of Inlet Air 

    E-print Network

    Meher-Homji, C. B.; Mani, G.

    1983-01-01

    in the ambient temperature. On hot days, a machine may experience considerable difficulty in meeting its power demand. One concept that has not received much attention is the cooling down of compressor inlet air. This paper will examine the theoretical...

  15. Laser spark ignition and combustion characteristics of methane-air mixtures

    SciTech Connect

    Ma, J.X.; Alexander, D.R.; Poulain, D.E. [Univ. of Nebraska, Lincoln, NE (United States)] [Univ. of Nebraska, Lincoln, NE (United States)

    1998-03-01

    Ignition breakdown kernels of methane-air mixtures initiated by laser-induced sparks and by conventional electric sparks are compared during initial stages. Experiments were conducted using a four-stroke (Otto-cycle) single-cylinder typical high-pressure combustion chamber. The piston is cycled in the cylinder by using an electric motor driven hydraulic ram. An excimer laser beam, either produced from krypton fluoride gas ({lambda} = 248 nm) or argon fluoride gas ({lambda} = 193 nm), or a Nd:YAG laser beam ({lambda} = 1,064 nm) is focused into a combustion chamber to initiate ignition. Conventional electric spark ignition is used as a basis for comparison between the two different ignition methods and the resultant early breakdown kernel characteristics. A streak camera is used to investigate and record the initial stages of kernel formation. Both a breakdown and a radial expansion wave of the ignition plasma are observed for certain laser ignition conditions of methane-air mixtures under typical internal combustion (IC) engine conditions. Results indicate that only certain wavelengths used for producing laser ignition produce a radial expansion wave. Laser ignition kernel size is calculated and laser-supported breakdown velocity is calculated by using Raizer`s theory and is compared with measured results. Laser ignition results in a 4--6 ms decrease in the time for combustion to reach peak pressure than is obtained when using electric spark ignition in the same combustion chamber and under the same ignition conditions.

  16. 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.

  17. Bulk damage effects in standard and oxygen-enriched silicon detectors induced by 60Co-gamma radiation

    Microsoft Academic Search

    E. Fretwurst; G. Lindström; J. Stahl; I. Pintilie; Z. Li; J. Kierstead; E. Verbitskaya; R. Röder

    2003-01-01

    The influence of oxygen in silicon on bulk damage effects induced by 60Co-gamma irradiation has been studied in a dose range between 0.2 and 900Mrad. The detector processing and oxygen enrichment were carried out in a common project by the Institute of Micro-sensors CiS using n-type high-resistivity FZ silicon (3–6k?cm) with ?111? and ?100? orientation. Different oxygen concentrations were achieved

  18. Air pollution and lung cancer: diesel exhaust, coal combustion

    SciTech Connect

    Higgins, I.T.

    1984-03-01

    It is known, that cigarette smoking is by far the most important cause of lung cancer and that about a dozen occupational exposures are also established as causes of this disease. There has been continuing uncertainty about the role of general air pollution. During the past few years, this uncertainty has been compounded with anxiety that the increasing use of diesel-powered vehicles might lead to a deterioration in air quality and, with it, an increase in the incidence of lung cancer. The purpose of this paper is to assess the current role of air pollution as a factor in lung cancer and specifically the contribution of diesel exhaust emissions to the incidence of that disease.

  19. 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.

  20. GASEOUS EMISSIONS FROM EXCESS AIR COMBUSTION OF EXPLOSIVES AND PROPELLANTS

    EPA Science Inventory

    The purpose of this short-term project was to determine the levels of nitric oxide (NO), nitrogen dioxide (NO2), and carbon monoxide (CO) in the off-gases from the open burning of explosives in excess air. The ultimate goal is to reduce the level of NO(x), CO, and particulates em...

  1. Recent air emission test data from several waste-to-energy facilities utilizing Martin GmbH Stoker combustion systems and advanced air pollution control equipment

    Microsoft Academic Search

    J. L. Hahn; H. P. VonDemFarge; R. A. Zurlinden; J. F. Scholz; M. T. Turner; D. B. Sussman; P. Z. Kubin

    1987-01-01

    The authors present air emission test data from several Martin GmbH stoker combustion systems utilizing advanced air pollution control equipment. These data greatly enhanced the body of emission data for use in predicting air emissions for modern waste-to-energy facilities. In addition, certain air emissions, e.g. Cr{sup +6}, have been quantified for the first time from dry scrubber\\/fabric filter air pollution

  2. Formation, ignition, and combustion of a stratified-charge fuel-air mixture in an open-chamber combustion bomb. [Thesis

    Microsoft Academic Search

    1975-01-01

    The interrelated processes of mixture formation, ignition, and the early stages of combustion that occur in one type of open-chamber, stratified-charge engines were studied experimentally by simulating engine conditions in a constant-volume combustion bomb. The apparatus designed and developed for this research permits a well-controlled single injection of liquid fuel into a steady-state environment of hot, high-pressure, fan-driven swirling air

  3. Premixed CH4/O2-enriched air combustion: Identification of thermal, chemical and aerodynamic effects

    NASA Astrophysics Data System (ADS)

    Most, J.-M.; Dahikar, S.; Pal, S.; Claverie, A.; Denis, D.; Pillier, L.; de Persis, S.

    2012-11-01

    This work contributes to the evaluation of a new innovative process focused on the reduction of the cost of a post-combustion capture of CO2 in a Carbon Capture and Storage system (CCS). The process based on the separation of dried fumes composed mainly by CO2 and N2 by using membranes, which should lead to a lower energetic separation cost than amines. But the membranes become efficient if the upstream CO2 concentration is higher than 30% at their entrance that requires enriching the oxidizer flow by O2. To maintain the exhaust temperature compatible with materials thermal resistance, the reactants are diluted by a recirculation of a part of the flue gases (like N2/O2/CO2). But, the chemical kinetic, the energetic efficiencies, the radiation transfer, the transport and thermal properties of the flow can be affected by CO2. The objective of this work will be to identify the behaviour of the combustion of premixed CH4/O2-enriched air, both diluted in N2 and CO2 and to determine the combustion parameters. This allows to recover the CH4/air conditions in terms of CO2 concentration in reactants, O2 excess, dilution rate, temperature of the reactants, etc. Experiments are performed on the laminar premixed flame using counterflow burner. To characterize the combustion behaviour, the flammability limits are determined and flame thickness and position are measured from PLIF-OH diagnostic. Further, CHEMKIN simulations are performed to check the validity of the GRI3.0 chemical kinetic mechanism for premixed CH4/air synthetic combustion and identify the leading phenomena.

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

    Microsoft Academic Search

    Glenn C England; Thomas P McGrath; Lee Gilmer; James G Seebold; Miriam Lev-On; Timothy Hunt

    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

  5. The application of combustion diagnostics to low NO{sub x} overfire air systems

    SciTech Connect

    Thompson, R.E.; Muzio, L.J.; Quartucy, G.C. [Fossil Energy Research Corp., Laguna Hills, CA (United States)

    1995-12-31

    Many post-retrofit NO{sub x} control systems for coal-fired utility boilers utilize overfire air (OFA) to limit NO{sub x} emissions but often at the expense of an increase in fly ash carbon content. Although, staged combustion conditions and coal properties have often been cited as reasons for increased fly ash carbon content and LOI, very little work has been done in evaluating the effectiveness of the OFA system. This paper outlines combustion diagnostic and analysis techniques for evaluating OFA mixing, penetration, and combustion uniformity on typical wall-fired, and tangentially-fired boilers. Field test data are provided illustrating the results of combustion diagnostic testing on two coal-fired units, a 155 MW front wall-fired unit and a 250 MW tangentially-fired unit. The techniques discussed in this paper include the use of a custom multi-point emissions analyzer that generates real-time NO{sub x}, O{sub 2}, and CO concentration profiles at the economizer exit. This instrumentation has proved valuable in evaluating combustion uniformity and making burner zone or OFA adjustments to minimize NO{sub x} emissions.

  6. 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.

  7. Development of a hybrid-fuzzy air temperature controller for a supersonic combustion test facility

    Microsoft Academic Search

    M. Owens; C. Segal

    2001-01-01

    Hydrogen gas is burned in air to raise and maintain the stagnation temperature of a supersonic combustion test facility to\\u000a a desired setpoint. In order to reach the desired operating conditions for stagnation temperature, there are three phases\\u000a to the hydrogen control; H2 ignition at facility start-up, H2 ramp-up while the facility is ramped-up, and H2 iteration to achieve the

  8. Evaluating Fuel-Air Mixing in a Direct-Injection Hydrogen-Fueled Internal Combustion Engine

    NASA Astrophysics Data System (ADS)

    Ebadi, Alireza; White, Christopher

    2012-11-01

    Proper orthogonal decomposition (POD) is used to decompose in-cylinder particle image velocimetry (PIV) vector fields acquired in a direct injection hydrogen-fueled internal combustion engine (DI-H2ICE) into mean, coherent, and incoherent vector fields, where the coherent vector fields are presumed to capture the cycle-variability of the flow. The POD vector fields are then used to investigate the effects of fuel injection timing on in-cylinder turbulence and fuel-air mixing.

  9. Effect of laser radiation and electric field on combustion of hydrocarbon-air mixtures

    Microsoft Academic Search

    P. K. Tretyakov; A. V. Tupikin; V. N. Zudov

    2009-01-01

    Publications on combustion of hydrocarbon-air mixtures under the action of a weak electric field and laser radiation are analyzed.\\u000a A specific feature of the authors’ experimental study is a pulsed-periodic action of an electric field and focused laser radiation,\\u000a which does not lead to electric discharge or optical breakdown. Numerous experiments reveal a noticeable effect of weak electric\\u000a fields on

  10. Unique, clean-air, continuous-flow, high-stagnation-temperature facility for supersonic combustion research

    NASA Technical Reports Server (NTRS)

    Krauss, R. H.; Mcdaniel, J. C., Jr.; Scott, J. E., Jr.; Whitehurst, R. B., III; Segal, C.

    1988-01-01

    Accurate, spatially-resolved measurements can be conducted of a model supersonic combustor in a clean air/continuous flow supersonic combustion facility whose long run times will allow not only the point-by-point mapping of flow field variables with laser diagnostics but facilitate the simulation of steady-state combustor conditions. The facility will provide a Mach 2 freestream with static pressures in the 1 to 1/6 atm range, and stagnation temperatures of up to 2000 K.

  11. Modeling, Dynamic Simulation, and Controller Design for an Air-breathing Combustion System

    Microsoft Academic Search

    P. Bharani; Chandra Kumar; Nitin K. Gupta; N. Ananthkrishnan; V. S. Renganathan

    2009-01-01

    A novel, high-fidelity, low-order model is developed for an air-breathing combustion system designed for supersonic flight with a subsonic combustor. Individual components - intake, combustor, exhaust nozzle - are modeled with detailed models obtained from CFD, quasi-1D, or isentropic analysis, as the case may be. The components are then interlinked by a low-order global model that captures the physics of

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

    DOEpatents

    Tuttle, Kenneth L. (Federal Way, WA)

    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. Effect of supplementation of water vapor to the environmental characteristics of the combustion of propane-air mixture

    NASA Astrophysics Data System (ADS)

    Larionov, V. M.; Mitrofanov, G. A.; Iovleva, O. V.

    2014-11-01

    To improve the efficiency of combustion of fuel gas and air can be used additive steam. The article presents the results of an experimental study of the influence of water vapor on the combustion of propane-butane mixture with air. Combustion mixture produced in a modified Bunsen burner. Studies carried change of steam temperature of 180 to 260 degrees Celsius, and the change of the specific volume steam in the composition of the fuel mixture. Influence steam on combustion was estimated by the change of temperature of heating the quartz tube. It has been established that the increase of the steam temperature and increasing the specific volume of the heated vapor in the composition of the gaseous fuel increases the temperature of combustion.

  14. Combustion

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The process whereby a substance is combined with oxygen with the production of heat. Burning is a familiar example of this process. The energy required to propel chemical rockets is provided by the combustion of fuel with an oxidant at very high temperatures. A common oxidant is liquid oxygen (often denoted by LOX). Others include hydrogen peroxide and nitrogen tetroxide....

  15. 77 FR 37361 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-21

    ...Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines AGENCY: Environmental Protection...Pollutants for Reciprocating Internal Combustion Engines; New Source...

  16. Fate of hazardous air pollutants in oxygen-fired coal combustion with different flue gas recycling.

    PubMed

    Zhuang, Ye; Pavlish, John H

    2012-04-17

    Experiments were performed to characterize transformation and speciation of hazardous air pollutants (HAPs), including SO(2)/SO(3), NO(x), HCl, particulate matter, mercury, and other trace elements in oxygen-firing bituminous coal with recirculation flue gas (RFG) from 1) an electrostatic precipitator outlet or 2) a wet scrubber outlet. The experimental results showed that oxycombustion with RFG generated a flue gas with less volume and containing HAPs at higher levels, while the actual emissions of HAPs per unit of energy produced were much less than that of air-blown combustion. NO(x) reduction was achieved in oxycombustion because of the elimination of nitrogen and the destruction of NO in the RFG. The elevated SO(2)/SO(3) in flue gas improved sulfur self-retention. SO(3) vapor could reach its dew point in the flue gas with high moisture, which limits the amount of SO(3) vapor in flue gas and possibly induces material corrosion. Most nonvolatile trace elements were less enriched in fly ash in oxycombustion than air-firing because of lower oxycombustion temperatures occurring in the present study. Meanwhile, Hg and Se were found to be enriched on submicrometer fly ash at higher levels in oxy-firing than in air-blown combustion. PMID:22439940

  17. 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.

  18. Apparatus for controlling the air supply to the intake manifold of an internal combustion engine

    SciTech Connect

    Lieuwen, W.O.

    1980-12-09

    Apparatus for controlling the air supply to the intake manifold of an internal combustion engine is described that has an intake system comprising a carburetor, the carburetor having a throttle, means for admitting air from the atmosphere and conducting the air to the carburetor for mixing with fuel, and conduit means for conducting the mixture of air and fuel from the carburetor to the intake manifold, the apparatus comprising auxiliary conduit means for conducting fuel-free air into the engine, the auxiliary conduit means communicating with the intake system at a point downstream of the throttle, a displaceable member associated with the auxiliary conduit means, the displaceable member being displaceable between a position in which the member blocks the access of air from the auxiliary conduit to the intake manifold and positions in which the member at least partly opens access of air from the auxiliary conduit to the intake manifold, an electromagnet associated with the displaceable member for controlling the displacement of the member, means for controlling the energization of the electromagnet, the energization controlling means including at least one switch responsive to pressure variations occurring in the intake system, and means for transmitting pressure variations from the intake system to the pressure responsive switch thereby to actuate the pressure responsive switch.

  19. 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.

  20. 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.

  1. Membrane Techniques in Air Cleaning

    Microsoft Academic Search

    M. Bodzek

    The state of the art of application of membrane techniques for air cleaning is presented. The most characteristic parameters of membrane separation of gases and vapours are described. Separation of gases and vapours has been applied practically in the industry for the following areas: removal of volatile organics from the air and from industrial waste flows, oxygen enrichment of air

  2. 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.

  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. 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.

  5. Transient air-fuel ratio H? preview control of a drive-by-wire internal combustion engine

    Microsoft Academic Search

    Larry Mianzot; Huei Pengt; I. Haskara

    2001-01-01

    An approach for H? Preview control of the transient air-fuel ratio control of a drive-by-wire internal combustion engine system is proposed. The fuel delivery system has significant transport and measurement delays. A preview fuel control algorithm, which uses the current measurement or estimate of air charge as well as the corresponding predicted future air charge, provides compensation for these delays.

  6. 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

  7. The experimental study on regenerative heat transfer in high temperature air combustion

    NASA Astrophysics Data System (ADS)

    Jia, Li; Li, Jianshu

    2004-11-01

    For the purpose of decomposing the processing gases CF4 from semiconductor manufacturers, ceramic honeycomb regenerative burner system is suggested by using the principle of HTAC. A simulated high temperature air combustion furnace has been used to determine the features of HTAC flames and the results of the decomposition of CF4. The preheat air temperature of it is above 900°C. The exhaust gas released into the atmosphere is lower than 150°C. Moreover, the efficiency of recovery of waste heat is higher than 80%, the NOx level in exhaust gas is less than 198 mg/m3 and the distribution of temperature in the furnace is nearly uniform. The factors influencing on heat transfer, temperature profile in chamber and NOx emission were discussed. Also some CF4 can be decomposed in this system.

  8. Fuel-air mixing and combustion in a two-dimensional Wankel engine

    NASA Technical Reports Server (NTRS)

    Shih, T. I.-P.; Schock, H. J.; Ramos, J. I.

    1987-01-01

    A two-equation turbulence model, an algebraic grid generalization method, and an approximate factorization time-linearized numerical technique are used to study the effects of mixture stratification at the intake port and gaseous fuel injection on the flow field and fuel-air mixing in a two-dimensional rotary engine model. The fuel distribution in the combustion chamber is found to be a function of the air-fuel mixture fluctuations at the intake port. It is shown that the fuel is advected by the flow field induced by the rotor and is concentrated near the leading apex during the intake stroke, while during compression, the fuel concentration is highest near the trailing apex and is lowest near the rotor. It is also found that the fuel concentration near the trailing apex and rotor is small except at high injection velocities.

  9. Calculating the parameters of self-oscillations in the vertical combustion chamber of the blast-furnace air heater during unstable combustion

    NASA Astrophysics Data System (ADS)

    Basok, B. I.; Gotsulenko, V. V.

    2015-01-01

    A procedure for simplified calculation of the parameters of self-oscillations excited during unstable (vibrating) combustion in the vertical combustion chambers of blast-furnace air heaters is developed. The proposed procedure is based on an independent nonlinear dynamic system similar to the equations from the theory of a blade supercharger stalling and surging mode. The head characteristic considered in the blade supercharger stalling and surging theory determines the part of the supercharger drive rotation energy that is converted into the head developed by the supercharger. In the considered system, the supercharger head characteristic is replaced by the combustion chamber head characteristic. Being a function of flow rate, this characteristic describes the part of heat supplied to flow that is converted to the flow head. Unlike the supercharger head characteristic, which is determined by experiment, the combustion chamber head characteristic is determined by calculation, due to which it becomes much easier to calculate the parameters of self-oscillations according to the proposed procedure. In particular, an analysis of the periodic solutions of the obtained dynamic system made it possible to determine the pattern in which the amplitude of considered self-oscillations depends on the surge impedance of the vertical combustion chamber.

  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 [Delft University Technology, Delft (Netherlands). Section Energy Technology, Department of Process and Energy

    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. 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.

  12. Polychlorinated naphthalenes in Great Lakes air: assessing spatial trends and combustion inputs using PUF disk passive air samplers

    SciTech Connect

    Tom Harner; Mahiba Shoeib; Todd Gouin; Pierrette Blanchard [Environment Canada, Toronto, ON (Canada). Science & Technology Branch

    2006-09-01

    Passive air samplers made from polyurethane foam (PUF) disks housed in stainless steel chambers were deployed over four seasons during 2002-2003, at 15 sites in the Laurentian Great lakes, to assess spatial and temporal trends of polychlorinated naphthalenes (PCNs). Sampling rates, determined using depuration compounds pre-spiked into the PUF disk prior to exposure, were, on average, 2.9 {+-} 1.1 m{sup 3} d{sup -1}, consistent with previous studies employing these samplers. PCN air concentrations exhibited strong urban-rural differences - typically a few pg m{sup 3} at rural sites and an order of magnitude higher at urban sites (Toronto, 12-31 pg m{sup -3} and Chicago, 13-52 pg m{sup -3}). The high concentrations at urban sites were attributed to continued emissions of historically used technical PCN. Contributions from combustion-derived PCNs seemed to be more important at rural locations where congeners 24 and 50, associated with wood and coal burning, were elevated. Congener 66/67, associated with incineration and other industrial thermal processes, was elevated at two sites and explained by nearby and/or upwind sources. Probability density maps were constructed for each site and for every integration period were shown to be a useful complement to seasonally integrated passive sampling data to resolve source-receptor relationship for PCNs and other pollutants. 25 refs., 7 figs., 1 tabs.

  13. Simulating Combustion

    Microsoft Academic Search

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

    2006-01-01

    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

  14. Commercialization of Turbulent Combustion Code CREBCOM for Chemical Industry Safety

    SciTech Connect

    Rohatgi, Upendra

    2007-06-30

    This program developed the Kurchatov Institute’s CREBCOM (CRiteria and Experimentally Based COMbustion) code to the point where it could be commercialized and marketed for the special applications described above, as well as for general purpose combustion calculations. The CREBCOM code uses a different approach to model the explosion phenomenon. The code models, with full 3D gas dynamics, the development of an explosion in three characteristics regimes: a) slow flames, b) fast flames, and c) detonation. The transition from one regime to another is governed by a set of empirical criteria and correlations. As part of the commercialization, the code was validated with the use of experimental data. The experimental data covered a range of thermodynamic initial conditions and apparatus scale. Proprietary experimental data were provided to the Kurchatov Institute by the DuPont for this purpose. The flame acceleration and detonation data was obtained from experiments in methane and oxygen enriched air mixtures carried out in two vessels with diameters of 20 and 27 cm. The experimental data covers a wide spectrum of initial temperature (20-525C) and pressure (1-3 atm). As part of this program, the Kurchatov Institute performed experiments in a 52 cm vessel in mixtures of methane-air at room temperature and pressure to be used in the validation of the code. The objective of these tests was to obtain frame acceleration data at a scale close to that found in actual industrial processes. BNL was responsible for managing the DOE/IPP portion of the program, and for satisfying DOE reporting requirements. BNL also participated in an independent assessment of the CREBOM code. DuPont provided proprietary experimental data to the Kurchatov Institute on flame acceleration and detonation in high temperature methane and oxygen enriched air mixtures in addition to the matching fund. In addition, DuPont also supplied to KI instrumentation for pressure and temperature measurement. Kurchatov (KI) performed experiments at close to full-scale in mixtures of room temperature methane and air to develop the CREBCOM code which was used for explosion simulation in confined geometrics, such as chemical reactors and converters. The code was validated by comparison of the code simulations with experimental data obtained under prototypic reactor mixture conditions.

  15. 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.

  16. 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.

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

    DOEpatents

    Staiger, Chad L. (Albuquerque, NM); Vaughn, Mark R. (Albuquerque, NM); Miller, A. Keith (Albuquerque, NM); Cornelius, Christopher J. (Blackburg, VA)

    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.

  18. Computations of spray, fuel-air mixing, and combustion in a lean-premixed-prevaporized combustor

    NASA Technical Reports Server (NTRS)

    Dasgupta, A.; Li, Z.; Shih, T. I.-P.; Kundu, K.; Deur, J. M.

    1993-01-01

    A code was developed for computing the multidimensional flow, spray, combustion, and pollutant formation inside gas turbine combustors. The code developed is based on a Lagrangian-Eulerian formulation and utilizes an implicit finite-volume method. The focus of this paper is on the spray part of the code (both formulation and algorithm), and a number of issues related to the computation of sprays and fuel-air mixing in a lean-premixed-prevaporized combustor. The issues addressed include: (1) how grid spacings affect the diffusion of evaporated fuel, and (2) how spurious modes can arise through modelling of the spray in the Lagrangian computations. An upwind interpolation scheme is proposed to account for some effects of grid spacing on the artificial diffusion of the evaporated fuel. Also, some guidelines are presented to minimize errors associated with the spurious modes.

  19. Combustion Air Preheat and Radiant Heat Transfer in Fired Heaters - A Graphical Method for Design and Operating Analysis

    E-print Network

    Grantom, R. L.

    1981-01-01

    heat transfer efficiency thereby enabling the transfer of the same amount of energy from a lower total heat release in the radiant box. This paper presents a graphical procedure that can be used (1) to estimate fuel savings obtained by combustion air...

  20. Ignition in conditions where a jet of fuel-air mixture interacts with the wall of a diesel combustion chamber

    Microsoft Academic Search

    V. K. Baev; A. A. Buzukov; B. P. Timoshenko

    1995-01-01

    The dependence of the ignition delay and the limitting detonation temperature of fuel-air mixture on the geometric characteristics of the wall of a diesel combustion chamber at which a high-speed jet is incident is investigated experimentally on a motorless setup. It is shown that, to facilitate ignition in the characteristic conditions of diesel startup, glancing initial incidence of the jet

  1. Extinguishment of methane diffusion flames by inert gases in coflow air and oxygen-enriched microgravity environments

    Microsoft Academic Search

    Fumiaki Takahashi; Gregory T. Linteris; Viswanath R. Katta

    2011-01-01

    Extinguishment of laminar coflow diffusion flames in microgravity (?g) have been studied experimentally and computationally. The ?g experiments were conducted using a methane cup-burner flame aboard the NASA Reduced-Gravity Aircraft. Transient computations with full methane chemistry and a gray-gas radiation model were performed to reveal the flame structure and extinguishment processes. In ?g, as an inert gas (N2, He, or

  2. Numerical Simulation on Hydrodynamics and Combustion in a Circulating Fluidized Bed under O2/CO2 and Air Atmospheres

    NASA Astrophysics Data System (ADS)

    Zhou, W.; Zhao, C. S.; Duan, L. B.; Qu, C. R.; Lu, J. Y.; Chen, X. P.

    Oxy-fuel circulating fluidized bed (CFB) combustion technology is in the stage of initial development for carbon capture and storage (CCS). Numerical simulation is helpful to better understanding the combustion process and will be significant for CFB scale-up. In this paper, a computational fluid dynamics (CFD) model was employed to simulate the hydrodynamics of gas-solid flow in a CFB riser based on the Eulerian-Granular multiphase model. The cold model predicted the main features of the complex gas-solid flow, including the cluster formation of the solid phase along the walls, the flow structure of up-flow in the core and downward flow in the annular region. Furthermore, coal devolatilization, char combustion and heat transfer were considered by coupling semi-empirical sub-models with CFD model to establish a comprehensive model. The gas compositions and temperature profiles were predicted and the outflow gas fractions are validated with the experimental data in air combustion. With the experimentally validated model being applied, the concentration and temperature distributions in O2/CO2 combustion were predicted. The model is useful for the further development of a comprehensive model including more sub-models, such as pollutant emissions, and better understanding the combustion process in furnace.

  3. Combustion of high-sulfur coal and anthracite wastes in a rotary kiln combustor with an advanced internal air distributor

    SciTech Connect

    Cobb, J.T. Jr. (Pittsburgh Univ., PA (USA)); Ahn, Y.K. (Gilbert/Commonwealth, Inc., Reading, PA (USA)); Angelo, J.F. (Universal Energy International, Inc., Little Rock, AR (USA))

    1990-01-01

    Fluid bed combustors have received extensive testing with both high-sulfur coal and anthracite wastes. Rotary kilns are effective and popular devices for waste combustion. The Angelo Rotary Furnace{trademark} has been developed to improve the operation of rotary pyrolyzer/combustor systems through enhanced air distribution, which in this process is defined as staged, swirled combustion air injection. Fourteen of these new furnaces have been installed worldwide. Two units in Thailand, designed for rice hull feed with occasional lignite feed, have been recently started up. An older unit in Pennsylvania is being upgraded with a new, more advanced air distribution system for a series of tests this fall in which inexpensive high-sulfur coal and anthracite wastes will be fired with limestone. The purposes of these tests are to determine the burning characteristics of these two fuels in this system, to discover the Ca/S ratios necessary for operation of a rotary kiln combusting these fuels, and to observe the gas-borne emissions from the furnace. An extensive preliminary design study will be performed on a commercial installation for combustion of anthracite wastes. 14 refs., 5 figs., 1 tab.

  4. 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.

  5. 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.

  6. 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

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

    Microsoft Academic Search

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

    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

  8. Air pollution combustion emissions: characterization of causative agents and mechanisms associated with cancer, reproductive, and cardiovascular effects.

    PubMed

    Lewtas, Joellen

    2007-01-01

    Combustion emissions account for over half of the fine particle (PM(2.5)) air pollution and most of the primary particulate organic matter. Human exposure to combustion emissions including the associated airborne fine particles and mutagenic and carcinogenic constituents (e.g., polycyclic aromatic compounds (PAC), nitro-PAC) have been studied in populations in Europe, America, Asia, and increasingly in third-world counties. Bioassay-directed fractionation studies of particulate organic air pollution have identified mutagenic and carcinogenic polycyclic aromatic hydrocarbons (PAH), nitrated PAH, nitro-lactones, and lower molecular weight compounds from cooking. A number of these components are significant sources of human exposure to mutagenic and carcinogenic chemicals that may also cause oxidative and DNA damage that can lead to reproductive and cardiovascular effects. Chemical and physical tracers have been used to apportion outdoor and indoor and personal exposures to airborne particles between various combustion emissions and other sources. These sources include vehicles (e.g., diesel and gasoline vehicles), heating and power sources (e.g., including coal, oil, and biomass), indoor sources (e.g., cooking, heating, and tobacco smoke), as well as secondary organic aerosols and pollutants derived from long-range transport. Biomarkers of exposure, dose and susceptibility have been measured in populations exposed to air pollution combustion emissions. Biomarkers have included metabolic genotype, DNA adducts, PAH metabolites, and urinary mutagenic activity. A number of studies have shown a significant correlation of exposure to PM(2.5) with these biomarkers. In addition, stratification by genotype increased this correlation. New multivariate receptor models, recently used to determine the sources of ambient particles, are now being explored in the analysis of human exposure and biomarker data. Human studies of both short- and long-term exposures to combustion emissions and ambient fine particulate air pollution have been associated with measures of genetic damage. Long-term epidemiologic studies have reported an increased risk of all causes of mortality, cardiopulmonary mortality, and lung cancer mortality associated with increasing exposures to air pollution. Adverse reproductive effects (e.g., risk for low birth weight) have also recently been reported in Eastern Europe and North America. Although there is substantial evidence that PAH or substituted PAH may be causative agents in cancer and reproductive effects, an increasing number of studies investigating cardiopulmonary and cardiovascular effects are investigating these and other potential causative agents from air pollution combustion sources. PMID:17951105

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Research test facility for evaporation and combustion of alternative jet fuels at high air temperatures. Annual technical report, 1 February 1983-30 January 1984

    Microsoft Academic Search

    J. E. Peters; H. Krier; K. K. Kim; R. E. Coverdill; J. E. Kirwan

    1984-01-01

    Improved gas turbine combustion performance will require the effective utilization of alternative fuels and advanced combustor concepts. Further understanding of spray combustion processes including fuel evaporation and flame propagation is required. Research underway features a high-pressure and -temperature non-vititated air system to provide air at simulated gas-turbine inlet conditions. A special fuel-injection system was designed to produce monodisperse sprays for

  14. 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.

  15. 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 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.

  16. Waste combustion as a source of ambient air polybrominated diphenylethers (PBDEs)

    NASA Astrophysics Data System (ADS)

    Wyrzykowska-Ceradini, Barbara; Gullett, Brian K.; Tabor, Dennis; Touati, Abderrahmane

    2011-08-01

    The first comprehensive set of U.S. data on polybrominated diphenylether (PBDE) concentrations from municipal waste combustion (MWC), with more than 40 PBDE congeners reported, was compared to ambient air levels of PBDEs in the U.S. The PBDE profiles in the raw MWC flue gas reflected the historical production and usage pattern of PBDE-based flame retardants in North America, which favored Penta- and Deca- BDE formulations. The pattern of selected, routinely measured in the environment, PBDEs (TeBDE-47, PeBDE-99, PeBDE-100, HxBDE-153 and DcBDE-209) was similar in the MWC emissions and profiles most commonly reported for the U.S. atmosphere. The mean ? PBDE concentrations in the clean flue gases collected from the stack were 0.13 and 1.7 ng dscm -1 during the steady state and transients of MWC, respectively (which was 98.6% reduction compare to the levels in the raw flue gases). The major PBDE congeners in the MWC flue gases were those typically found in PBDE technical mixes (TeBDE-47, PeBDE-99, PeBDE-100, HxBDE-153, HpBDE-183, OcBDE-197, NoBDE-206, NoBDE-207, NoBDE-208, DcBDE-209). The profile of the PBDEs in the raw flue gas was dominated by heavier congeners, especially DcBDE-209, while the profile of the stack flue gases profile was dominated by the lighter congeners (TeBDE-47, PeBDE-99, PeBDE-100 accounted for around 80% of total stack emissions). Some of the MWC flue gas samples exhibited enrichment of lower brominated congeners that are minor or not present in the technical mixtures, suggesting that debromination occurs during combustion. Congeners substituted in non- and mono- ortho positions (TeBDE-77, PeBDE-126, HxBDE-156 and -169) were detected mostly during the transients of MWC.

  17. 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.

  18. 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...

  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. Combustion Control

    E-print Network

    Riccardi, R. C.

    1984-01-01

    . Because each furnace is designed and operated differently, careful evaluation is required. Look at several options. The performance and efficiency of a combustion system depends upon several major factors. They are: 1) Fuel to air ratio control, 2) Fuel...

  1. Environmental exposure to combustion-derived air pollution is associated with reduced functional capacity in apparently healthy individuals.

    PubMed

    Steinvil, Arie; Shmueli, Hezzy; Ben-Assa, Eyal; Leshem-Rubinow, Eran; Shapira, Itzhak; Berliner, Shlomo; Kordova-Biezuner, Levana; Rogowski, Ori

    2013-08-01

    Prior toxicological exposure reports demonstrated the decremental effect of several air pollutants on the metabolic equivalents achieved during exercise testing (METs). There are no prior large scale epidemiological reports about the effect of environmental air pollution exposure on those parameters. We analyzed a cohort of apparently healthy individuals attending a screening survey program held between 2003 and 2009. Participants were included if residing within an 11 km radius from the nearest air pollution monitoring station. Linear regression models were fitted for the metabolic equivalents and adjusted to short- and long-term air pollutant exposure (particulate matter under 10 micron, sulfur dioxide, nitrogen dioxide, carbon monoxide and ozone). The models were adjusted for possible confounders that affect air pollution and stress testing measurements. The study population comprised 6,612 individuals (4,201 males and 2,411 females). We found a statistically significant short- and long-term negative correlation between air pollutants, mainly CO and NO2 and between the metabolic equivalents achieved. A similar short-term effect was found for SO2. We conclude that exposure to combustion-derived air pollutants has a short- and long-term decremental effect on cardiorespiratory fitness as measured by exercise stress testing. Our epidemiological data support previous toxicological reports. PMID:23619759

  2. 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.

  3. Internal combustion engine

    Microsoft Academic Search

    Lowther

    1980-01-01

    An internal combustion engine method and apparatus are described wherein most or all of the air compression required for combustion is done outside of the internal combustion engine and out of heat exchange contact with the combustion chamber. The engine includes direct regeneration of exhaust heat and the compressor includes means for varying the compression ratio thereof in response to

  4. Rotary internal combustion engine

    SciTech Connect

    Le, L.K.

    1990-11-20

    This patent describes an internal combustion engine comprising; a rotary compressor mechanism; a rotary expander mechanism; and combustion chamber means disposed between the compressor mechanism and the expander mechanism, whereby compressed air is delivered to the combustion chamber through the compressor discharge port, and pressurized gas is delivered from the combustion chamber into the expander mechanism through the pressurized gas intake port.

  5. 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.

  6. Air–fuel mixing and combustion in a small-bore direct injection optically accessible diesel engine using a retarded single injection strategy

    Microsoft Academic Search

    Tiegang Fang; Robert E. Coverdill; Chia-fon F. Lee; Robert A. White

    2009-01-01

    In this paper, the air–fuel mixing and combustion in a small-bore direct injection optical diesel engine were studied for a retarded single injection strategy. The effects of injection pressure and timing were analyzed based on in-cylinder heat release analysis, liquid fuel and vapor fuel imaging by Laser induced exciplex fluorescence technique, and combustion process visualization. NOx emissions were measured in

  7. 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

  8. 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.

  9. Development of the utilization of combustible gas produced in existing sanitary landfills: investigation of effects of air inclusion

    SciTech Connect

    Not Available

    1983-01-01

    A combustible gas mixture composed of methane and carbon dioxide is generated in municipal solid waste landfills. A practical consequence of the collection of this fuel gas is the inclusion of some air in the collected product. The effects of such included nitrogen and oxygen on landfill gas operations are discussed. The effects include increased collection and purification costs, reduction in the quality of the fuel gas produced, corrosion, explosion hazards, and interference with odorant systems. The scope of such effects was determined using data and experience from the Mountain View, California, landfill gas recovery site as a basis. Useful supplemental fuel gas may be recovered despite the inclusion of air. Recommendations are given for establishing limits for nitrogen and oxygen content and minimizing the costs associated with their presence.

  10. Membrane-based air separation for catalytic oxidation of isolongifolene

    Microsoft Academic Search

    Fawen Wu; Zhihong Xu; Zhixiang Wang; Yiqiang Shi; Lei Li; Zhibing Zhang

    2010-01-01

    Oxygen-enriched air (OEA) from membrane-based air separation has been widely used in the industrial field in the past two decades. Isolongifolenone, an oxygenated derivative of isolongifolene, is an important perfume ingredient in the perfumery industry. In this paper, the OEA produced by the membranes was employed as oxidant to convert isolongifolene into isolongifolenone with cobaltous acetate as catalyst. The effects

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

    Microsoft Academic Search

    Szpunar

    1992-01-01

    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

  12. 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.

  13. 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.

  14. 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.

  15. 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 ?g/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.

  16. Maintain Combustion Systems 

    E-print Network

    Fletcher, R. J.

    1979-01-01

    Energy is consumed, and wasted, in liberal amounts in the combustion processes which supply heat energy to boilers and process heaters. Close attention to combustion systems can be extremely beneficial: Optimum air to fuel ratios, i.e., maintaining...

  17. Estimation of Fuel Savings by Recuperation of Furnace Exhausts to Preheat Combustion Air 

    E-print Network

    Rebello, W. J.; Kohnken, K. H.; Phipps, H. R., Jr.

    1980-01-01

    , it is necessary to be able to estimate the fuel saved by use of such a system. Standard industrial practice refers to the method described in the North American Combustion Handbook with its curves and tables that directly predict the percentage fuel savings...

  18. 66 FR 3180 - National Emission Standards for Hazardous Air Pollutants for Chemical Recovery Combustion Sources...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2001-01-12

    ...combustion units using total hydrocarbon (THC) as a surrogate for gaseous organic HAP...gaseous organic HAP emissions (as measured by THC reported as carbon) from these units by...organic HAP emission limit (as measured by THC reported as carbon) of 1.49...

  19. 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...

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

    SciTech Connect

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

    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.

  1. CHARACTERIZATION OF INCIDENTAL CARBONACEOUS NANOPARTICLES IN AMBIENT AIR AND COMBUSTION EXHAUST

    EPA Science Inventory

    The most important result of this research is one of the most complete datasets to date on the presence of C60 in the aerosol phase in the natural environment. This study expects that C60 fullerenes will not be found at detectable levels in combustion exhaust, ambient carbo...

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

    SciTech Connect

    Wesnor, J.D. [ABB/Combustion Engineering, Inc., Windsor, CT (United States)

    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.

  3. Multiple ignition, normal and catalytic combustion and quenching of fuel\\/air mixtures. Annual report

    Microsoft Academic Search

    C. Burns; F. V. Bracco; H. S. Homan; W. A. Sirignano

    1980-01-01

    Lean combustion of propane in platinum\\/alumina\\/cordierite catalysts has been studied at atmospheric pressure, gas velocities of 10-40 m\\/s, C3H8 equivalence ratios of .19 to .32 and H2O concentration of 1.2 to 1.7 mol %. Measurements of substrate temperature and gas composition, pressure, and temperature inside and downstream of the catalyst have been made. The dependences of substrate temperature, gas temperature,

  4. Evaluation of environmentally acceptable coal combustion technology to increase coal use at CONUS Air Force Base

    Microsoft Academic Search

    F. L. Beason; R. M. Schilling; J. F. Thomas

    1991-01-01

    The purpose of this paper is to explain the findings of the investigative phase of the Air Force Coal Utilization Program. The objective of this program is to place the Air Force in compliance with the intent of the Defense Appropriations Act as it relates to using additional coal in Department of Defense (ODD) Continental United States (COINS) facilities. The

  5. 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.

  6. 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.

  7. Model of Non-premixed Combustion of Aluminium---Air Mixtures

    Microsoft Academic Search

    Boris Khasainov; Allen Kuhl; Sergey Victorov; Peter Neuwald

    2005-01-01

    For solving the problem of shock-induced dissemination and burning of aluminium particles in air, we have developed a new solver based on equilibrium equation of states (EOS) of 2-phase reactive mixtures. The solver uses two pre-calculated tables; the larger one describes the equilibrium states of reaction products and the smaller one describes states of fresh air. Being linked with gas-dynamics

  8. BOOK REVIEW: Turbulent Combustion

    Microsoft Academic Search

    Norbert Peters

    2001-01-01

    The book Turbulent Combustion by Norbert Peters is a concise monograph on single-phase gaseous low Mach number turbulent combustion. It is compiled from the author's review papers on this topic plus some additional material. Norbert Peters characterizes turbulent combustion both by the way fuel and air are mixed and by the ratio of turbulent and chemical time scales. This approach

  9. 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.

  10. 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. (Environmental Protection Agency, Research Triangle Park, NC (USA)); He, X.Z.; Cao, S.R.; Xian, Y.L.; Li, X.M. (Institute of Environmental Health and Engineering, Beijing (China))

    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.

  11. 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.

  12. INDOOR AIR SAMPLING AND MUTAGENICITY STUDIES RELATED TO EMISSIONS FROM UNVENTED COAL COMBUSTION

    EPA Science Inventory

    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 ...

  13. Internal combustion engine

    Microsoft Academic Search

    G. Perrin; H. Bergmann

    1984-01-01

    An externally auto-ignited four-stroke internal combustion engine which includes a combustion chamber disposed in an upper surface of a piston such that, in an upper dead-center position of the piston, the combustion chamber receives almost all of the fuel-air mixture. The combustion chamber includes a planar bottom portion and has a cross-sectional shape of a truncated cone expanding in a

  14. 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 furnace should be considered to improve the deep-air-staging combustion configuration. PMID:24274316

  15. 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.

  16. 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

  17. Internal combustion engines and method of operating an internal combustion engine using staged combustion

    SciTech Connect

    Stanley, R.S.

    1991-12-31

    A method of operating an internal combustion engine with a split chamber design for stage combustion comprising the steps of: forming at least one primary combustion chamber and at least one secondary combustion chamber in association with a cylinder means having at least two regions formed therein and piston means within the engine, causing air within the cylinder means to flow through the at least one primary combustion chamber at a predetermined rate and volume; admitting a predetermined amount of fuel to the at least one primary combustion chamber to form a fuel/air mixture, therein; igniting the fuel/air mixture within the at least one primary combustion chamber to generate a first stage of combustion; causing the flow of the the ignited fuel/air mixture to the at least one secondary combustion chamber for continued burning of the fuel/air mixture in a second stage of combustion within the at least one secondary combustion chamber. This patent also describes a split chamber, staged combustion internal combustion engine. It comprises means defining a cylinder having at least two regions formed therein, piston means; combustion chambers; fuel delivery means; and means for igniting the fuel in the primary combustion chamber.

  18. Packed Bed Combustion: An Overview

    E-print Network

    Hallett, William L.H.

    Packed Bed Combustion: An Overview William Hallett Dept. of Mechanical Engineering Université d'Ottawa - University of Ottawa #12;Packed Bed Combustion - University of Ottawa - CICS 2005 Introduction air fuel feedproducts xbed grate Packed Bed Combustion: fairly large particles of solid fuel on a grate, air supplied

  19. Internal combustion engines and method of operating an internal combustion engine using staged combustion

    Microsoft Academic Search

    1991-01-01

    A method of operating an internal combustion engine with a split chamber design for stage combustion comprising the steps of: forming at least one primary combustion chamber and at least one secondary combustion chamber in association with a cylinder means having at least two regions formed therein and piston means within the engine, causing air within the cylinder means to

  20. 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

  1. Simulation of CO-H2-air Turbulent Diffusion Flame by the Combustion Model Combined Chemical Equilibrium Method with the Eddy Dissipation Concept Model

    NASA Astrophysics Data System (ADS)

    Fukumoto, Kazui; Ogami, Yoshifumi

    This research aims at building a turbulent diffusion combustion model based on chemical equilibrium and kinetics for simplifying complex chemical mechanisms. This paper presents the combustion model based on chemical equilibrium combined with an eddy dissipation concept model (CE-EDC); the model is validated by simulating a CO-H2-air turbulent diffusion flame. In the CE-EDC model, the reaction rate of fuels and intermediate species are estimated by using the equations of the EDC model. Then, the reacted fuels and intermediate species are assumed to be in chemical equilibrium; the amounts of the other species are determined by the Gibbs free energy minimization method by using the amounts of the reacted fuels, intermediate species, and air as reactants. An advantage of the CE-EDC model is that the amounts of the combustion products can be determined without using detailed chemical mechanisms. Moreover, it can also predict the amounts of the intermediate species. The obtained results are compared with Correa's experimental data and Gran's computational data by using the EDC model, which uses the complex chemical mechanisms. The mole fractions of CO, H2, H2O, OH, temperature, and mixture fraction obtained by using our CE-EDC model were in good agreement with these reference data. Using the present CE-EDC model, amounts of combustion products can be calculated by using a reduced chemical mechanism and the Gibbs free energy minimization theory. The accuracy of this model is in the same order as that of the EDC model.

  2. 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.

  3. Air-substrate mercury exchange associated with landfill disposal of coal combustion products.

    PubMed

    Xin, Mei; Gustin, Mae S; Ladwig, Kenneth; Pflughoeft-Hassett, Debra F

    2006-08-01

    Previous laboratory studies have shown that lignite-derived fly ash emitted mercury (Hg) to the atmosphere, whereas bituminous- and subbituminous-derived fly ash samples adsorbed Hg from the air. In addition, wet flue gas desulfurization (FGD) materials were found to have higher Hg emission rates than fly ash. This study investigated in situ Hg emissions at a blended bituminous-subbituminous ash landfill in the Great Lakes area and a lignite-derived ash and FGD solids landfill in the Midwestern United States using a dynamic field chamber. Fly ash and saturated FGD materials emitted Hg to atmosphere at low rates (-0.1 to 1.2 ng/ m2hr), whereas FGD material mixed with fly ash and pyrite exhibited higher emission rates (approximately 10 ng/m2hr) but were still comparable with natural background soils (-0.3 to 13 ng/ m2hr). Air temperature, solar radiation, and relative humidity were important factors correlated with measured Hg fluxes. Field study results were not consistent with corresponding laboratory observations in that fluxes measured in the latter were higher and more variable. This is hypothesized to be partially an artifact of the flux measurement methods. PMID:16933649

  4. 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. [Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, DK-2800 Kgs. Lyngby (Denmark)

    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)

  5. Impact of combustion products from Space Shuttle launches on ambient air quality

    NASA Technical Reports Server (NTRS)

    Dumbauld, R. K.; Bowers, J. F.; Cramer, H. E.

    1974-01-01

    The present work describes some multilayer diffusion models and a computer program for these models developed to predict the impact of ground clouds formed during Space Shuttle launches on ambient air quality. The diffusion models are based on the Gaussian plume equation for an instantaneous volume source. Cloud growth is estimated on the basis of measurable meteorological parameters: standard deviation of the wind azimuth angle, standard deviation of wind elevation angle, vertical wind-speed shear, vertical wind-direction shear, and depth of the surface mixing layer. Calculations using these models indicate that Space Shuttle launches under a variety of meteorological regimes at Kennedy Space Center and Vandenberg AFB are unlikely to endanger the exposure standards for HCl; similar results have been obtained for CO and Al2O3. However, the possibility that precipitation scavenging of the ground cloud might result in an acidic rain that could damage vegetation has not been investigated.

  6. NO.sub.x reduction method

    DOEpatents

    Sekar, Ramanujam R. (Naperville, IL); Hoppie, Lyle O. (West Bloomfield, MI)

    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.

  7. 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.

  8. 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...

  9. Internal combustion engine

    SciTech Connect

    Helmich, M.J.; Hoagland, M.C.; Hubbard, R.L.; Schaub, F.S.

    1981-12-22

    A method of combusting natural gas fuel in a two cycle, turbocharged internal combustion engine substantially reduces the production of nitrogen-oxygen emissions. An improved turbocharger design provides increased air charging pressure, produces a controlled lean air/fuel mixture and lowers peak combustion temperatures. A jet cell ignition device ensures uniform, reliable ignition of the lean air/fuel mixture under all operating conditions and the lean air/fuel mixture in turn encourages complete fuel combustion and provides excellent combustion characteristics with methane, ethane and heavier paraffinic hydrocarbon fuels. These structural modifications and adjustment of other operating parameters combine to reduce nitric oxide (NO) and nitrogen dioxide (NO/sub 2/) emissions by as much as 75% while effecting only a negligible increase in fuel consumption.

  10. EMISSIONS ASSESSMENT OF CONVENTIONAL STATIONARY COMBUSTION SYSTEMS: VOLUME V: INDUSTRIAL COMBUSTION SOURCES

    EPA Science Inventory

    The report characterizes air emissions from industrial external combustion sources and is the last of a series of five reports characterizing emissions from conventional combustion sources. The emissions characterization of industrial combustion sources was based on a critical ex...

  11. 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

  12. Membrane-based air composition control for light-duty diesel vehicles : a benefit and cost assessment.

    SciTech Connect

    Poola, R.; Stork, K.

    1998-11-09

    This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM2.5). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles. For nearly a decade, Argonne has been evaluating membrane-based methods to control the composition of air used in combustion. Membranes are the only practical method of modifying air composition for on-board use. The applicability of the technique depends strongly on both the technical and economic feasibility of implementing it on a vehicle. Over the past 10 years, significant technical advances have been made in the development of air-separation membranes. Researchers have developed and commercialized novel membrane materials that can efficiently separate air at the concentrations required for vehicle applications and have developed compact membrane modules that can be incorporated into vehicle design. Previous analysis by Argonne and others has demonstrated the effectiveness of oxygen enrichment at reducing PM, smoke, hydrocarbon (HC), and carbon monoxide (CO) emissions while increasing engine power output. Under appropriate oxygen-enriched operating conditions, diesel engines have achieved a net increase of 10-20% in power density and a decrease of 30-60% in PM emissions. Nitrogen-enriched air can be used as an alternative to exhaust gas recirculation to control NO{sub x} emissions and can also be used to generate a monatomic nitrogen plasma for exhaust post-treatment to reduce emissions of NO{sub x}. Argonne has recently identified an operating regime that can simultaneously reduce NO{sub x} and PM while increasing power output when oxygen-enriched combustion air is used. This promising technique, which will be verified by additional experimental work at Argonne (using a range of engine sizes), will require the use of membranes similar to those analyzed in this study.

  13. Health effects of air pollution due to coal combustion in the Chestnut Ridge Region of Pennsylvania: results of cross-sectional analysis in adults.

    PubMed

    Schenker, M B; Speizer, F E; Samet, J M; Gruhl, J; Batterman, S

    1983-01-01

    Respiratory questionnaires (ATS-DLD-78) were administered to 5557 adult women in a rural area of Western Pennsylvania to evaluate the health effects of air pollution resulting from coal combustion. Air pollution data were derived from 17 air quality monitor sites and stratified to define low, medium, and high pollution areas. The means of 4 yr (1975-1978) annual averages for sulfur dioxide in each strata were 62, 66, and 99 micrograms/m3, respectively. Total suspended particulates were not tested as a risk factor because they reflected air pollution from sources other than coal combustion (e.g., agricultural, road dusts). Risks of respiratory symptoms were evaluated in a multiple logistic model that adjusted for several potential confounding factors. The risk of "wheeze most days or nights" in nonsmokers residing in the high and medium pollution areas was 1.58 and 1.26 (P = .02), respectively, relative to residents in the low pollution area. In the subset of residents who had lived in the same location for at least 5 yr, relative risks increased to 1.95 and 1.40 (P less than .01), respectively. An increased risk of grade 3 dyspnea in nonsmokers was associated with sulfur dioxide but did not achieve statistical significance (P = .11), and there was no association of cough or phlegm and air pollution in nonsmokers. Cigarette smoking characteristics were the major determinant of respiratory symptoms in smokers, and no independent association of air pollution was found. This study suggests that wheezing may be associated with ambient exposure to sulfur dioxide in nonsmokers, but no effect of sulfur dioxide on cigarette smokers was observed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6607712

  14. N-Decane-Air Droplet Combustion Experiments in the NASA-Lewis 5 Second Zero-Gravity Facility

    NASA Technical Reports Server (NTRS)

    Haggard, John B.; Brace, Michael H.; Dryer, Frederick L.; Choi, Mun Y.; Williams, Forman A.

    1990-01-01

    The burning of single fuel (n-decane) droplets in a microgravity environment (below 0.00001 of the earth's gravity, achieved in the NASA-Lewis 5-Second Zero-Gravity Facility) was studied, as part of the development of the Droplet Combustion Experiment for eventual operation aboard either the Shuttle middeck or Spacelab. Special attention is given to the combustion equipment used and its operations and performance. Temporal analysis of the local burning rates in these tests showed increasing rates of change in the local burning as droplet combustion progressed. Result point to the need of studying large droplets, with long droplet combustion lifetimes as well as low gas/droplet motion to understand reasons for this unsteadiness.

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

    Microsoft Academic Search

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

    2009-01-01

    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\\/?-Al2O3, LaMnO3\\/?-Al2O3, 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,

  16. Combustion Air Control 

    E-print Network

    Hughart, C. L.

    1979-01-01

    in unsatisfactory flue gas oxygen control. Simple tests provide the data needed to evaluate the potential success of closed-loop oxygen control and to identify major control deficiencies. These tests: - Measure the effect that changing boiler load has on flue gas...

  17. Pilot-scale demonstration of red water treatment by wet air oxidation and circulating bed combustion. Volume 1. Final project summary report, September 1993-October 1995

    SciTech Connect

    Scoville, W.; Hoye, R.; Acharya, P.; Martin, J.

    1995-10-01

    As part of the Army`s ongoing research and development program related to red water (KO47) treatment, the U.S. Army Environmental Center (USAEC) contracted IT Corporation to prepare conceptual designs and plans for pilot scale demonstrations of two treatment technologies: wet air oxidation (WAO) and circulating bed combustion (CBC). The Project Summary Report presents the conceptual designs. Because red water is not currently available for testing and the test site (host facility) where the demonstrations will be conducted has not been identified, these documents are intended to be generic in nature.

  18. Pilot scale demonstration of red water treatment by wet air oxidation and circulating bed combustion. Volume 2. Final project summary report, September 1993-October 1995

    SciTech Connect

    Scoville, W.; Hoye, R.; Acharya, P.; Martin, J.

    1995-10-11

    As part of the Army`s ongoing research and development program related to red water (KO47) treatment, the U.S. Army Environmental Center (USAEC) contracted IT Corporation to prepare conceptual designs and plans for pilot scale demonstrations of two treatment technologies: wet air oxidation (WAO) and circulating bed combustion (CBC). The Project Summary Report presents the conceptual designs. Because red water is not currently available for testing and the test site (host facility) where the demonstrations will be conducted has not been identified, these documents are intended to be generic in nature.

  19. Pilot scale demonstration of red water treatment by wet air oxidation and circulating bed combustion. Volume 3. Final project summary report, September 1993-October 1995

    SciTech Connect

    Scoville, W.; Hoye, R.; Acharya, P.; Martin, J.

    1995-10-11

    As part of the Army`s ongoing research and development program related to red water (KO47) treatment, the U.S. Army Environmental Center (USAEC) contracted IT Corporation to prepare conceptual designs and plans for pilot scale demonstrations of two treatment technologies: wet air oxidation (WAO) and circulating bed combustion (CBC). The Project Summary Report presents the conceptual designs. Because red water is not currently available for testing and the test site (host facility) where the demonstrations will be conducted has not been identified, these documents are intended to be generic in nature.

  20. Pilot scale demonstration of red water treatment by wet air oxidation and circulating bed combustion. Volume 4. Final project summary report, September 1993-October 1995

    SciTech Connect

    Scoville, W.; Hoye, R.; Acharya, P.; Martin, J.

    1995-10-11

    As part of the Army`s ongoing research and development program related to red water (KO47) treatment, the U.S. Army Environmental Center (USAEC) contracted IT Corporation to prepare conceptual designs and plans for pilot scale demonstrations of two treatment technologies: wet air oxidation (WAO) and circulating bed combustion (CBC). The Project Summary Report presents the conceptual designs. Because red water is not currently available for testing and the test site (host facility) where the demonstrations will be conducted has not been identified, these documents are intended to be generic in nature.

  1. Direct injection internal combustion engine of compression ignition type

    Microsoft Academic Search

    A. Saito; K. Kozuka; Y. Oshima; M. Yamada; N. Mori; K. Sugiyama; T. Aoyama

    1987-01-01

    This patent describes a direct injection internal combustion engine of a compression ignition type in which air is sucked into a combustion chamber and compressed by a piston, and fuel is injected directly thereinto so as to be ignited and combusted, comprising: air intake means having swirling means for swirling intake air supplied to the combustion chamber; a piston having

  2. Advanced Post-Combustion CO2 Capture Prepared for the

    E-print Network

    Advanced Post-Combustion CO2 Capture Prepared for the Clean Air Task Force under a grant from...................................................................................... 3 2. Current Status of Post-Combustion Capture

  3. Simulation of a Fractionated Vacuum Swing Adsorption Process for Air Separation

    Microsoft Academic Search

    Cheng-Tung Chou; Dou-Ming Ju; Shih-Chang Chang

    1998-01-01

    A fractionated vacuum swing adsorption process previously proposed in the literature that simultaneously produces a 98% nitrogen-enriched gas and a 90% oxygen-enriched gas from ambient air is studied by simulation. This process utilizes CaX zeolite as the major adsorbent and alumina as the desiccant packed at the feed air end. In the isothermal simulation the feed air is considered to

  4. 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.

  5. Opportunities in pulse combustion

    SciTech Connect

    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.

  6. Methane reforming and its potential effect on the efficiency and pollutant emissions of lean methane–air combustion

    Microsoft Academic Search

    J.-Y. Ren; W. Qin; F. N. Egolfopoulos; H. Mak; T. T. Tsotsis

    2001-01-01

    Results of ongoing studies of methane reforming for power generation applications are discussed. Design calculations are presented for a hybrid process (termed CRGT) involving chemical recuperation for power generation, and combining both reactive separation and combustion. Results are also presented from a parallel investigation, whose goal is to quantify the effect of the operational characteristics of the CRGT process on

  7. Double free-piston external combustion engine

    Microsoft Academic Search

    1987-01-01

    An external combustion engine is described comprising: means for supplying compressed air; a combustion member including an annular sleeve securing air inlet valving means and gas outlet valving means, fuel injection means and combustion ignition means, mounted on each side of the annular sleeve and positioned in diametrically opposed locations. Two conjugate free pistons are located inside the annular sleeve

  8. Emissions in combustion of lean methane-air and biomass-air mixtures supported by primary hot burned gas in a multi-stage gas turbine combustor

    Microsoft Academic Search

    Sadamasa Adachi; Atushi Iwamoto; Shigeru Hayashi; Hideshi Yamada; Shigehiko Kaneko

    2007-01-01

    Thermal reaction of lean to ultra-lean premixed mixtures supported by the hot burned gas from the up-stream stage can be used for obtaining a better trade-off between ultra-low-NOx and high combustion efficiency over a wide range of operations of a gas turbine. A three-stage model combustor designed based on this concept is being developed for a biomass gas-fueled regenerative cycle

  9. Quantifying the effects of exposure to indoor air pollution from biomass combustion on acute respiratory infections in developing countries.

    PubMed Central

    Ezzati, M; Kammen, D M

    2001-01-01

    Acute respiratory infections (ARI) are the leading cause of burden of disease worldwide and have been causally linked with exposure to pollutants from domestic biomass fuels in developing countries. We used longitudinal health data coupled with detailed monitoring and estimation of personal exposure from more than 2 years of field measurements in rural Kenya to estimate the exposure-response relationship for particulates < 10 microm diameter (PM(10)) generated from biomass combustion. Acute respiratory infections and acute lower respiratory infections are concave, increasing functions of average daily exposure to PM(10), with the rate of increase declining for exposures above approximately 1,000-2,000 microg/m(3). This first estimation of the exposure-response relationship for the high-exposure levels characteristic of developing countries has immediate and important consequences for international public health policies, energy and combustion research, and technology transfer efforts that affect more than 2 billion people worldwide. PMID:11401759

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

    SciTech Connect

    Scarpa, A. [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli ''Federico II'', P.le V. Tecchio 80, 80125 Naples (Italy); Department of Chemical Engineering, Center for Catalytic Science and Technology (CCST), and Center for Composite Materials (CCM), University of Delaware, 150 Academy Street, Newark, DE 19716 (United States); Pirone, R. [Istituto di Ricerche sulla Combustione-CNR, P.le V. Tecchio 80, 80125 Naples (Italy); Russo, G. [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli ''Federico II'', P.le V. Tecchio 80, 80125 Naples (Italy); Vlachos, D.G. [Department of Chemical Engineering, Center for Catalytic Science and Technology (CCST), and Center for Composite Materials (CCM), University of Delaware, 150 Academy Street, Newark, DE 19716 (United States)

    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)

  11. 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...

  12. Combustion Catalysts in Industry- An Update 

    E-print Network

    Merrell, G. A.; Knight, R. S.

    1985-01-01

    Combustion catalysts improve boiler efficiency by extracting more heat energy from the fuel and by reducing heat losses when operating at minimum excess air. In addition, an effective combustion catalyst may reduce the level of smoke and solid...

  13. 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. [and others

    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.

  14. N-Decane Droplet Combustion in the NASA-Lewis 5 Second Zero-Gravity Facility - Results in Test Gas Environments Other than Air

    NASA Technical Reports Server (NTRS)

    Haggard, John B.; Borowski, Brian A.; Dryer, Frederick L.; Choi, Mun Y.; Williams, Forman A.

    1991-01-01

    The burning rate of single droplets of n-decane in a microgravity environment of the NASA-Lewis 5 Second Zero-Gravity Facility was investigated as a function of time, together with the flame diameter/droplet diameter ratio, for a wide range of test environments other than normal air conditions, using an engineering model of the flight experiment. Oxygen mole fractions were varied from 18 to 50 percent, the total test chamber pressure was varied from 0.5 to 2 atmospheres, and the initial droplet diameter was varied from 0.98 to 2.41 mm. Measurements showed that the average burning rates for n-decane droplets exhibited the same qualitative trends as are found in two current models. Temporal analysis of the local burning rates showed variable rates of change in local burning as the droplet combustion progressed. The causes and implications of these findings are discussed.

  15. Health and safety plan for pilot-scale demonstration of red water treatment by wet air oxidation and circulating bed combustion. Final report, September 1993-October 1995

    SciTech Connect

    Scoville, W.; Hoye, R.; Acharya, P.; Martin, J.

    1995-10-11

    As part of the Army`s ongoing research and development program related to red water (KO47) treatment, the U.S. Army Environmental Center (USAEC) contracted IT Corporation to prepare conceptual designs and plans for pilot scale demonstrations of two treatment technologies: wet air oxidation (WAO) and circulating bed combustion (CBC). This Project Summary Report and the Test Plan and Health and Safety Plan are intended to serve as guides for development of complete project plans when the technology demonstration program is implemented. Because red water is not currently available for testing and the test site (host facility) where the demonstrations will be conducted has not been identified, these documents are intended to be generic in nature.

  16. Test plan for pilot-scale demonstration of red water treatment by wet air oxidation and circulating bed combustion. Final report, September 1993-October 1995

    SciTech Connect

    Scoville, W.; Hoye, R.; Acharya, P.; Martin, J.

    1995-10-11

    As part of the Army`s ongoing research and development program related to red water (KO47) treatment, the U.S. Army Environmental Center (USAEC) contracted IT Corporation to prepare conceptual designs and plans for pilot scale demonstrations of two treatment technologies: wet air oxidation (WAO) and circulating bed combustion (CBC). The project objectives included development of a Test Plan and a Health and Safety Plan for these demonstrations. The Project Summary Report presents the conceptual designs. This Project Summary Report and the Test Plan and Health and Safety Plan are intended to serve as guides for development of complete project plans when the technology demonstration program is implemented. Because red water is not currently available for testing and the test site (host facility) where the demonstrations will be conducted has not been identified, these documents are intended to be generic in nature.

  17. Studies of C2H6/ air and C3H8/ air Plasma assisted combustion kinetics in a nanosecond discharge

    E-print Network

    Ju, Yiguang

    speed aviation [1-5]. Development and successful running of hydrogen fuelled scramjets has been atmospheric air is compressed to supersonic speeds in scramjets to higher static pressures and temperatures

  18. Internal combustion engine with rotary combustion chamber

    Microsoft Academic Search

    C. N. Hansen; P. C. Cross

    1988-01-01

    This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber, means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means having an air and fuel intake passage, an exhaust gas passage,

  19. Internal combustion engine with rotary combustion chamber

    Microsoft Academic Search

    C. N. Hansen; P. C. Cross

    1986-01-01

    This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means has an air and fuel intake passage, and exhaust gas passage,

  20. 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.

  1. Forced air furnace control system and method of operation

    Microsoft Academic Search

    F. E. J. Hilt; J. W. E. Locke

    1993-01-01

    Forced air furnace apparatus is described for heating a building airspace with hot air, including the combination of a furnace having a combustion chamber for combusting fuel to produce hot combustion products which contain CO gas, heat exchanger means in the combustion chamber for normally separating the combustion products from a first air flow path and for transferring heat from

  2. 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...

  3. Swirl control arrangement for internal combustion engine

    SciTech Connect

    Nakajima, Y.; Yoshimura, T.; Terakasa, K.

    1987-03-24

    This patent describes, in an internal combustion engine having a combustion chamber, an induction system comprising: an induction passage leading to the combustion chamber; means for forming and air fuel mixture in one of the combustion chamber and the induction passage; an inlet valve which controls communication between the combustion chamber and the induction passage; a throttle valve disposed in the induction passage for controlling the amount of air which is inducted into the combustion chamber when the inlet valve is open; a swirl control valve disposed in the induction passage downstream of the throttle valve; a first sensor for sensing the pressure differential between the section of the induction passage upstream of the swirl control valve and the section of the induction passage downstream of the swirl control valve; a second sensor for sensing the air-fuel ration of the air-fuel mixture being combusted in the combustion chamber; a servo for controlling the position of the swirl control valve; and a control circuit responsive to the first and second sensors for controlling the servo in a manner to optimize the swirl generation within the combustion chamber for the air-fuel ratio of the air-fuel mixture being combusted in the combustion chamber.

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

    SciTech Connect

    Shaddix, Christopher R.; Haynes, Brian S. (University of Sydney, Sydney, Australia); 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.

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

    SciTech Connect

    Shaddix, Christopher R.; Haynes, Brian S. (University of Sydney, Sydney, Australia); 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.

  6. 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.

  7. 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.

  8. Oil and Gas Air Heaters 

    E-print Network

    Kou, G.; Wang, H.; Zhou, J.

    2006-01-01

    Most conventional air heaters adopt indirect heat transfer, which uses combustion gases to indirectly heat fresh air by heating surfaces to generate hot air used for material drying and dehumidification. We call them indirect air heaters. However...

  9. Preliminary evaluation of coal-fired fluid bed combustion-augmented compressed-air energy-storage power plants

    Microsoft Academic Search

    R. D. Lessard; A. J. Giramonti; D. Merrick

    1979-01-01

    The highlights are presented of a portion of an ongoing study program to assess the technical and economic feasibility of advanced concepts for generating peak-load electric power from a compressed air energy storage (CAES) power plant incorporating a coal-fired fluid bed combustor (FBC). Specifically, it reviews the analysis performed to select the FBC\\/CAES power plant system configuration for the subsequent

  10. Preliminary evaluation of coal-fired fluid bed combustion-augmented compressed air energy storage power plants

    Microsoft Academic Search

    R. D. Lessard; A. J. Giramonti; D. Merrick

    1980-01-01

    This paper presents highlights of an ongoing study program to assess the technical and economic feasibility of advanced concepts for generating peak-load electric power from a compressed air energy storage (CAES) power plant incorporating a coal-fired fluid bed combustor (FBC). It reviews the analyses performed to select an FBC\\/CAES power plant system configuration for the subsequent conceptual design phase of

  11. ORGANICS PROGRAM (AIR POLLUTION TECHNOLOGY BRANCH, AIR POLLUTION PREVENTION AND CONTROL DIVISION, NRMRL)

    EPA Science Inventory

    The organics research program of NRMRL's Air Pollution Prevention and Control Division's Air Pollution Technology Branch focuses on combustion derived products of incomplete combustion (PICs) with current emphasis on halogenated air toxics such as chlorinated dioxins/furans (PCDD...

  12. 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. [Lancaster Univ. (United Kingdom)] [Lancaster Univ. (United Kingdom)

    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.

  13. Mild Combustion of Methane-Derived Fuel Mixtures: Natural Gas and Biogas

    Microsoft Academic Search

    Alessandro Effuggi; Davino Gelosa; Marco Derudi; Renato Rota

    2008-01-01

    Mild combustion (also called diluted or flameless combustion) is an innovative combustion process able to strongly reduce pollutant emissions with respect to traditional combustion processes; it is characterized by high preheating of the combustion air and massive recycle of burned gases. While it is well known that mild combustion leads to lowering NOx emissions when pure fuels (such as methane)

  14. 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…

  15. A fluidized-bed combustion process with inherent CO 2 separation; application of chemical-looping combustion

    Microsoft Academic Search

    Anders Lyngfelt; Bo Leckner; Tobias Mattisson

    2001-01-01

    For combustion with CO2 capture, chemical-looping combustion has the advantage that no energy is lost for the separation of CO2. In chemical-looping combustion oxygen is transferred from the combustion air to the gaseous fuel by means of an oxygen carrier. The fuel and the combustion air are never mixed, and the gases from the oxidation of the fuel, CO2 and

  16. Rotary internal combustion engine

    SciTech Connect

    Murray, J.L.

    1993-07-20

    A multi bank power plant is described comprising at least a first and a second rotary internal combustion engine connectable together in series, each of the engines comprising: a housing; a cam track internally disposed within the housing and adapted to receive a cam follower; an engine block disposed within the housing and rotatable about a central axis; an output shaft extending axially from each the engine block, each output shaft being coaxial with the other; means for coupling the output shafts together so that the output shafts rotate together in the same direction at the same speed; at least one radially arranged cylinder assembly on each block, each cylinder assembly including a cylinder having a longitudinal axis extending generally radially outwardly from the rotational axis of the block, the cylinder including means defining an end wall, a piston member disposed within the cylinder and adapted to reciprocate within the cylinder; a combustion chamber, means permitting periodic introduction of air and fuel into the combustion chamber, means for causing combustion of a compressed mixture of air and fuel within the combustion chamber, means permitting periodic exhaust of products of combustion of air and fuel from the combustion chamber, and means for imparting forces and motions of the piston within the cylinder to and from the cam track, the means comprising a cam follower operatively connected to the piston; wherein the cam track includes at least a first segment and at least a second segment thereof, the first segment having a generally positive slope wherein the segment has a generally increasing radial distance from the rotational axis of the engine block whereby as a piston moves outwardly in a cylinder on a power stroke while the cam follower is in radial register with the cam track segment, the reactive force of the respective cam follower against the cam track segment acts in a direction tending to impart rotation to the engine block.

  17. Compressed air energy storage system

    DOEpatents

    Ahrens, Frederick W. (Naperville, IL); Kartsounes, George T. (Naperville, IL)

    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.

  18. Rotary internal combustion engine

    Microsoft Academic Search

    Kollen

    1987-01-01

    This patent describes a rotary internal combustion engine operating on fuel and air, comprising: a housing having a pair of communicating parallel axis rotor chambers; a pair of parallel axis rotors, one in each rotor chamber of the housing, the rotors each having on its outer periphery circumferentially spaced axial teeth with intervening circumferentially spaced axial passages. The rotors are

  19. 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.

  20. Internal combustion engine using premixed combustion of stratified charges

    DOEpatents

    Marriott, Craig D. (Rochester Hills, MI); 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.

  1. 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 system were delivered to VPTNA and then assembly of APA engine was completed by June 2007. Functional testing of APA engine was performed and AC and AM modes testing were completed by October 2007. After completing testing, data analysis and post processing were performed. Especially, the models were instrumental in identifying some of the key issues with the experimental HVA system. Based upon the available engine test results during AC and AM modes, the projected fuel economy improvement over the NY composite cycle is 14.7%. This is close to but slightly lower than the originally estimated 18% from ADVISOR simulation. The APA project group demonstrated the concept of APA technology by using simulation and experimental testing. However, there are still exists of technical challenges to meet the original expectation of APA technology. The enabling technology of this concept, i.e. a fully flexible valve actuation system that can handle high back pressure from the exhaust manifold is identified as one of the major technical challenges for realizing the APA concept.

  2. Spray combustion

    SciTech Connect

    Chigier, N. [Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Mechanical Engineering

    1995-12-31

    A survey is presented of the most recent developments in the field of spray combustion. Topics discussed are: physical processes of atomization; drop clusters; droplet arrays and streams; ideal sprays; cloud combustion; theoretical models of spray diffusion flames; spray diagnostic techniques; measurement of drop temperature; and spray combustion measurements. 67 refs.

  3. Increasing the efficiency of an air separation plant by varying the cycle stage durations

    Microsoft Academic Search

    V. K. Bel’nov; N. M. Voskresenskii; D. M. Predtechenskaya; M. S. Safonov; L. I. Kheifets

    2007-01-01

    A mathematical model of a plant for oxygen-enriched air production by pressure swing adsorption is proposed. The model takes\\u000a into account the experimentally determined actual dependence of the longitudinal dispersion coefficient on the gas velocity\\u000a and the sorbent particle size. The relationship between the plant efficiency and the duration of each of the operating cycle\\u000a stages is studied using an

  4. Internal combustion engine with stepped piston supercharger

    Microsoft Academic Search

    1979-01-01

    A reciprocating piston four cycle internal combustion engine utilizes a stepped piston the stepped portion of which, working in an enlarged bore in the block, serves as a compressor to provide a supercharged fuel-air mixture to the combustion chamber. The compressor delivers two compression strokes per engine cycle. The compressed fuel-air mixture travels from the compressor via a bypass manifold,

  5. Gas turbine alternative fuels combustion characteristics

    Microsoft Academic Search

    R. James Rollbuhler

    1989-01-01

    An experimental investigation was conducted to obtain combustion performance and exhaust pollutant concentrations for specific synthetic hydrocarbon fuels. Baseline comparison fuels used were gasoline and diesel fuel number two. Testing was done over a range of fuel to air mass ratios, total mass flow rates, and input combustion air temperatures in a flame-tube-type gas turbine combustor. Test results were obtained

  6. ON THE COMBUSTION CHARACTERISTICS OF SAWDUST IN A CYCLONE COMBUSTOR

    Microsoft Academic Search

    Bundit Fungtammasan; Prajak Jittrepit

    This paper discusses experimental results on the combustion characteristics of sawdust in a cyclone combustor in which sawdust and air are injected into the combustion chamber through two tangential inlets. Data obtained for flow visualization under isothermal flow conditions, flame stability, combustion temperature mapping and combustion-product composition analyses are presented. It is observed that sawdust particles, except for the very

  7. 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

    This report is a presentation of work carried out on Phase II of the HIPPS program under DOE contract DE-AC22-95PC95144 from June 1995 to March 2001. The objective of this report is to emphasize the results and achievements of the program and not to archive every detail of the past six years of effort. These details are already available in the twenty-two quarterly reports previously submitted to DOE and in the final report from Phase I. The report is divided into three major foci, indicative of the three operational groupings of the program as it evolved, was restructured, or overtaken by events. In each of these areas, the results exceeded DOE goals and expectations. HIPPS Systems and Cycles (including thermodynamic cycles, power cycle alternatives, baseline plant costs and new opportunities) HITAF Components and Designs (including design of heat exchangers, materials, ash management and combustor design) Testing Program for Radiative and Convective Air Heaters (including the design and construction of the test furnace and the results of the tests) There are several topics that were part of the original program but whose importance was diminished when the contract was significantly modified. The elimination of the subsystem testing and the Phase III demonstration lessened the relevance of subtasks related to these efforts. For example, the cross flow mixing study, the CFD modeling of the convective air heater and the power island analysis are important to a commercial plant design but not to the R&D product contained in this report. These topics are of course, discussed in the quarterly reports under this contract. The DOE goal for the High Performance Power Plant System ( HIPPS ) is high thermodynamic efficiency and significantly reduced emissions. Specifically, the goal is a 300 MWe plant with > 47% (HHV) overall efficiency and {le} 0.1 NSPS emissions. This plant must fire at least 65% coal with the balance being made up by a premium fuel such as natural gas. 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 issues of fabrication and reliability, availability and maintenance. The program that has s

  8. Coal combustion system

    DOEpatents

    Wilkes, Colin (Lebanon, IN); Mongia, Hukam C. (Carmel, IN); Tramm, Peter C. (Indianapolis, IN)

    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.

  9. 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.

  10. Indoor Air Pollution from Biomass Combustion and its Adverse Health Effects in Central India: An Exposure-Response Study

    PubMed Central

    Sukhsohale, Neelam D; Narlawar, Uday W; Phatak, Mrunal S

    2013-01-01

    Background: Some of the highest exposures to air pollutants in developing countries occur inside homes where biofuels are used for daily cooking. Inhalation of these pollutants may cause deleterious effects on health. Objectives: To assess the respiratory and other morbidities associated with use of various types of cooking fuels in rural area of Nagpur and to study the relationship between the duration of exposure (exposure index [EI]) and various morbidities. Materials and Methods: A total of 760 non-smoking, non-pregnant women aged 15 years and above (mean age 32.51 ? 14.90 years) exposed to domestic smoke from cooking fuels from an early age, working in poorly ventilated kitchen were selected and on examination presented with various health problems. Exposure was calculated as the average hours spent daily for cooking multiplied by the number of years. Symptoms were enquired by means of a standard questionnaire adopted from that of the British Medical Research Council. Lung function was assessed by the measurement of peak expiratory flow rate (PEFR). PEFR less than 80% of the predicted was considered as abnormal pulmonary function. Results and Conclusions: Symptoms like eye irritation, headache, and diminution of vision were found to be significantly higher in biomass users (P < 0.05). Abnormal pulmonary function, chronic bronchitis, and cataract in biomass users was significantly higher than other fuel users (P < 0.05). Moreover an increasing trend in prevalence of symptoms/morbid conditions was observed with increase in EI. The presence of respiratory symptoms/morbid conditions was associated with lower values of both observed and percent predicted PEFR (P < 0.05 to 0.001). Thus women exposed to biofuels smoke suffer more from health problems and respiratory illnesses when compared with other fuel users. PMID:24019602

  11. The mechanism of two-dimensional pocket formation in lean premixed methane-air flames with implications to turbulent combustion

    SciTech Connect

    Chen, J.H.; Echekki, T. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility] [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Kollmann, W. [Univ. of California, Davis, CA (United States). Mechanical and Aerospace Engineering Dept.] [Univ. of California, Davis, CA (United States). Mechanical and Aerospace Engineering Dept.

    1999-01-01

    The mechanism of unburnt pocket formation in an unsteady two-dimensional premixed lean methane-air flame is investigated using direct numerical simulations. Theoretical results for nonlinear diffusion equations combined with analytical examples are used to interpret some of the results. Flame structure and propagation show three distinct stages of pocket formation: (1) flame channel closing involving head-on quenching of flames, (2) cusp recovery, and (3) pocket burnout. The flame channel closing and subsequent pocket burnout are mutual annihilation events that feature curvature, diffusion normal to the flame front, unsteady strain rate effects, and singularities in flame propagation and stretch rate. The results show that during channel closing and pocket burnout thermo-diffusive and chemical interactions result in the acceleration of the flames prior to annihilation; the time scales associated with the final stage of mutual annihilation and the initial stage of cusp recovery are significantly smaller than diffusive and convective time scales. Peak radical concentrations resulting from flame channel closing and pocket burnout exceed peak laminar values by as much as 25%. After the merging of the fuel consumption layers, radical production and flame structure shifts more towards an H{sub 2}/CO/O{sub 2} system at the expense of hydrocarbon reactions. Species thermodiffusive interaction times are shorter than the unstrained one-dimensional counterpart due to unsteady strain and convection. Curvature effects on the flame propagation are prominent during pocket burnout and cusp recovery. The recovery stage shows strong dependence on diffusion of radicals left from the channel closing stage. This diffusion is amplified by the strong curvature of the flame cusp.

  12. Paper # B03 Topic: Turbulent Flames US Combustion Meeting

    E-print Network

    Pitsch, Heinz

    and efficiency to predict NOx and CO emissions from the furnace with a cross-flow- jet combustion system cross-flow air injection into the incomplete combustion products. Figure 1 illustrates the configuration-fire part of the furnace to complete combustion. The cross-flow air jets introduce rapid mixing

  13. 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

    NONE

    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.

  14. Internal combustion rotary engine

    SciTech Connect

    Chen, S.P.

    1993-08-24

    An internal combustion rotary engine is described comprising: an internal combustion chamber wherein a combustible fuel-air mixture is ignited for producing a driving gas flow; a central rotor having an outer surface in which at least one group of curved channels circumferentially-and-axially extending without radially extending through the central rotor; and at least one annular rotor each enclosing the central rotor having an inner surface in which a corresponding number of curved channels circumferentially-and-axially extending without radially extending through the annular rotor; when the curved channels in the central rotor communicate with the curved channels in the annular rotor, the driving gas flow circumferentially-and-axially passing between the outer surface of the central rotor and the inner surface of the annular rotor for rotating the central rotor and the annular rotor in opposite directions.

  15. 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.

  16. 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.

  17. CO 2 capture from coal combustion using chemical-looping combustion - Reactivity investigation of Fe, Ni and Mn based oxygen carriers using syngas

    Microsoft Academic Search

    Tobias Mattisson; Marcus Johansson; Anders Lyngfelt

    Chemical-looping combustion (CLC) is a combustion technology where an oxygen carrier is used to transfer oxygen from the combustion air to the fuel, thus avoiding direct contact between air and fuel. The system is composed of two reactors, a fuel and an air reactor, where the flue gas from the fuel reactor contains CO 2 and H 2O and the

  18. The effects of spark ignition parameters on the lean burn limit of natural gas combustion in an internal combustion engine 

    E-print Network

    Chlubiski, Vincent Daniel

    1997-01-01

    A full factorial experiment was conducted to determine the effects of internal combustion engine ignition parameters on the air-fuel ratio (A/F) lean limit of combustion with compressed natural gas (CNG). Spark electrical characteristics (voltage...

  19. Comment/Rebuttal Comments on "Electrorheology Leads to Efficient Combustion" by

    E-print Network

    Gülder, Ömer L.

    Comment/Rebuttal Comments on "Electrorheology Leads to Efficient Combustion" by Tao et al. O¨ mer L of combustion in general and internal combustion (IC) engine combustion technology in particular. Given posit that "because combustion starts at the interface between fuel and air and most harmful emissions

  20. Carbureted prechamber rotary combustion engine

    Microsoft Academic Search

    Tabaczynski

    1974-01-01

    A Wankel engine is designed with a main chamber and a prechamber substantially smaller than the main chamber. A lean air-fuel mixture is delivered to the main chamber while a rich air-fuel mixture is supplied to the prechamber section. The rich air-fuel mixture in the prechamber is ignited, creating a pressure differential which causes hot combustion gases in prechamber to

  1. 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).

  2. Industrial Application of High Combustion Intensity Systems and Energy Conservation Implications 

    E-print Network

    Williams, F. D. M.; Anderson, L. E.

    1982-01-01

    combustion equipment at stoichiometric conditions is emphasized. The calculated fuel savings resulting from elimination of excess air and use of heat recovery air preheat are reviewed. Design parameters for the aerodynamic design and control of the combustion...

  3. Piston and process for achieving controlled ignition and combustion of hydrocarbon fuels in internal combustion engines by generation and management

    SciTech Connect

    Failla, C.C.; Pouring, A.A.; Rankin, B.; di Priolo, C.L.; Mc Cowan, W.; Gosewisch, D.

    1990-02-06

    This patent describes an improvement in a piston for a reciprocating piston internal combustion engine in which a combustion cycle is carried out in a variable volume combustion chamber defined by the piston reciprocating in a close ended cylinder into which a fuel and air charge is periodically supplied. The cycle includes intake, compression, combustion, expansion and exhaust portions. The piston crown is recessed and contains the majority of the charge when the combustion chamber is at minimum volume.

  4. Combustion Group Group members

    E-print Network

    Wang, Wei

    Combustion Group Group members: Thierry Poinsot, Emilien Courtine, Luc Vervisch, Benjamin Farcy § New combustion and energy-conversion concepts #12;Introduction Combustion research thrusts Combustion Dynamics and Flame-Stabilization Research objectives § Obtain fundamental understanding of combustion

  5. Combustion chamber for internal combustion engine

    Microsoft Academic Search

    Isida

    1988-01-01

    This patent describes a combustion chamber for an internal combustion engine, comprising: a main combustion chamber hollowed out of the top of a piston; a subsidiary combustion chamber hollowed out of the piston top, the subsidiary combustion chamber communicating with and disposed in side by side relationship to the main combustion chamber; a fuel injection nozzle located generally between the

  6. Catalytic Combustion of Syngas

    Microsoft Academic Search

    John Mantzaras

    2008-01-01

    The catalytic combustion of syngas\\/air mixtures over Pt has been investigated numerically in a channel-flow configuration using 2D steady and transient computer codes with detailed hetero-\\/homogeneous chemistry, transport, and heat transfer mechanisms in the solid. Simulations were carried out for syngas compositions with varying H2 and CO contents, pressures of 1 to 15 bar, and linear velocities relevant to power

  7. Combustion-gas recirculation system

    DOEpatents

    Baldwin, Darryl Dean (Lacon, IL)

    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.

  8. 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...

  9. Carburetor for internal combustion engines

    SciTech Connect

    Peterson, R.W.

    1986-09-23

    This patent describes a carburetor for an internal combustion engine which includes a source of fuel and combustion chambers, the carburetor including a body surrounding an air passage, a venturi section in the air passage and throttle means for controlling the passage of air through the air passage, the carburetor further comprising a primary fuel circuit having a first metering valve for introducing fuel from the fuel source directly into the air passage to produce a relatively lean fuel-to-air mixture, first operating means for operating the first metering valve in conjunction with the throttle means whereby each incremental movement of the throttle means produces a proportional incremental operation of the first metering valve, a secondary fuel circuit having a second metering valve for introducing additional fuel from the fuel source directly into the air passage for enriching the fuel-to-air mixture, and second operating means for operating the second metering valve in conjunction with the air pressure in the venturi section in the air passage, the second operating means being adapted to be responsive to the air pressure in the venturi section and to produce a proportional incremental operation of the second metering valve in response to incremental changes in the air pressure in the venturi section.

  10. Dynamics of deflagrations and reactive systems: Heterogeneous combustion; International Colloquium on Dynamics of Explosions and Reactive Systems, 12th, University of Michigan, Ann Arbor, July 23-28, 1989, Technical Papers

    Microsoft Academic Search

    A. L. Kuhl; J.-C. Leyer; A. A. Borisov; W. A. Sirignano

    1991-01-01

    The present colloquium on the dynamics of explosions and reactive systems discusses combustion of dust-air mixtures, droplet combustion, combustion at solid and liquid surfaces, and combustion diagnostics. Attention is given to deflagration and detonation combustion of dust mixtures, experiments on unconfined dust-air flames, experimental measurement of the aerodynamic entrainability of dust deposits, and starch dust combustion characteristics in a closed

  11. Combustion of pulverized coal in various atmospheres

    Microsoft Academic Search

    K. C. Chang; G. F. Berry; C. S. Wang; A. M. Wolsky

    1985-01-01

    In this modeling study, a one-dimensional coal combustion or gasification (1-DICOG) computer code was used to simulate differences in the combustion performance of pulverized coal resulting from the substitution of various COâ\\/Oâ mixtures for air in the combustion atmosphere. Predictions using this simple, one-dimensional model were compared with actual performance data from tests conducted by Battelle Columbus Laboratories. The resulting

  12. Combustion synthesis

    Microsoft Academic Search

    Kashinath C Patil; Singanahally T Aruna; Sambandan Ekambaram

    1997-01-01

    Many innovative self-propagating high-temperature synthesis (SHS) techniques such as filtration, combustion, the centrifugal thermite process, field activated combustion, solid-state metathesis, flame synthesis and simultaneous SHS and densification have been developed for the synthesis of ‘advanced materials’. A novel gas producing self-propagating process initiated at low temperature using redox compounds and mixtures has been used for the preparation of fine particle

  13. Method and system for controlled combustion engines

    DOEpatents

    Oppenheim, A. K. (Berkeley, CA)

    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.

  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. 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.

  16. Combustion chamber for internal combustion engines

    Microsoft Academic Search

    Kawamura

    1988-01-01

    A combustion chamber for internal combustion engines, of the type including means for producing swirl within the combustion chamber is described comprising: a combustion chamber provided in the head portion of a piston in the form of a cavity recessed in the axial direction of the piston; fuel injection nozzle means disposed in the combustion chamber and positioned eccentrically with

  17. Combustion chamber for internal combustion engines

    Microsoft Academic Search

    N. Yanagisawa; Y. Sato

    1989-01-01

    A combustion chamber is described for an internal combustion engine, comprising: a main combustion chamber defined by a recess in the top of a piston of the engine, the main combustion chamber being formed with its opening diameter progressively enlarged downwards in the axial direction of the main combustion chamber, and a lip part formed along the periphery of the

  18. Investigation Of Synergistic NOx Reduction From Cofiring And Air Staged Combustion Of Coal And Low Ash Dairy Biomass In A 30 Kilowatt Low NOx Furnace

    E-print Network

    Lawrence, Benjamin Daniel

    2013-08-01

    of 29590 kJ/kg for dry ash free (DAF) coal and 21450 kJ/kg for DAF DB. A new method called Respiratory Quotient (RQ), defined as ratio of carbon dioxide moles to oxygen moles consumed in combustion, used widely in biology, was recently introduced...

  19. Engine combustion chamber structure

    SciTech Connect

    Tanaka, H.

    1988-09-13

    This patent describes a combustion chamber structure comprising an upper wall surface which is shaped like a pent-roof and into which an intake passage opens, a piston having on a head portion thereof a bulged portion conforming to the upper wall surface in shape, a first bowl portion which is formed substantially at the center of the bulged portion and which is substantially semispherical in shape, a pair of second bowl portions which respectively extend on opposite sides of the first bowl portion to the corresponding ends of the bulged portion of the piston along the edge of the bulged portion and are in communication with the first bowl portion, a swirl generating means which is adapted to generate a swirl of intake air in the combustion chamber when the engine load is light, and a spark plug disposed to substantially face the center of the first bowl portion from the upper wall surface; the swirl generating means being adapted to generate the swirl of intake air in a tangential direction in the combustion chamber; and the diameter of the first bowl portion being larger than the width of the second bowl portion.

  20. Energy conservation in industrial operations - method and economics of improved combustion efficiencies. Topical report. Combustion-control systems for process heaters and boilers

    Microsoft Academic Search

    A. C. Varma; H. W. Jr. Prengle

    1979-01-01

    The importance and applications of modern combustion control systems for retrofitting existing boilers and heaters to increase combustion efficiency are discussed. The conventionally used heater control system and its deficiencies are discussed in detail and the need for modern control systems is stressed. Modern combustion control systems are designed to provide safe and efficient combustion and desired air\\/fuel ratio, reducing

  1. Post-Combustion CO2 Capture 11 -13 July 2010

    E-print Network

    Post-Combustion CO2 Capture Workshop 11 - 13 July 2010 Tufts European Center Talloires, France Institute | | Clean Air Task Force | | Asia Clean Energy Innovation Initiative | #12;Post-Combustion CO2 Capture Workshop 11 - 13 July 2010 Talloires, France PROCEEDINGS: Post-Combustion CO2 Capture Workshop

  2. 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...

  3. Combustion modeling in waste tanks

    SciTech Connect

    Mueller, C.; Unal, C. [Los Alamos National Lab., NM (United States); Travis, J.R. [Los Alamos National Lab., NM (United States)]|[Forschungszentrum Karlsruhe (Germany). Inst. fuer Reaktorsicherheit

    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.

  4. 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.

  5. Field testing: application of combustion modifications to control pollutant emissions from industrial boilers - Phase II. Final report Jul 1974Sep 1975

    Microsoft Academic Search

    G. A. Cato; L. J. Muzio; D. E. Shore

    1976-01-01

    The report gives results of testing 19 coal, oil, and gas-fired industrial boilers to determine their normal emissions and the effectiveness of combustion modifications in reducing NO(x) emissions without increasing the emission of particulates and other pollutants. Combustion modifications investigated were: reducing excess air, recirculating flue gas, staging combustion air, adjusting burner swirl registers, reducing combustion air temperature, tuning the

  6. Combustion characteristics of ducted rockets

    Microsoft Academic Search

    N. Kubota; K. Miyata; T. Kuwahara; M. Mitsuno; I. Nakagawa

    1991-01-01

    Since ducted rockets operate with the combustion of fuel-rich hot gas generated in a primary combustor and the ram-air induced from the atmosphere to a secondary combustor, the operational condition is strongly dependent on the physicochemical properties of the fuel-rich gas and the mixing\\/reaction process of the air flow in the secondary combustor. In order to obtain high energy fuel-rich

  7. Combustion Group Group members

    E-print Network

    Wang, Wei

    Combustion Group Group members: Thierry Poinsot, Emilien Courtine, Luc Vervisch, Benjamin Farcy 2014 #12;Combustion Group Combustion Physics and Modeling Pollutants, Emissions, and Soot Formation Thermoacoustics and Combustion Dynamics Research focus § Examine mechanisms responsible for flame stabilization

  8. 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, a computational model developed at Glenn, that simulates the cavitational collapse of a single bubble in a liquid (water) and the subsequent combustion of the gaseous contents inside the bubble. The model solves the time-dependent, compressible Navier-Stokes equations in one-dimension with finite-rate chemical kinetics using the CHEMKIN package. Specifically, parameters such as frequency, pressure, bubble radius, and the equivalence ratio were varied while examining their effect on the maximum temperature, radius, and chemical species. These studies indicate that the radius of the bubble is perhaps the most critical parameter governing bubble combustion dynamics and its efficiency. Based on the results of the parametric studies, we plan on conducting experiments to study the effect of ultrasonic perturbations on the bubble generation process with respect to the bubble radius and size distribution.

  9. Thick-film zinc-oxide gas sensor for the control of lean air-to-fuel ratio in domestic combustion systems

    Microsoft Academic Search

    Chul Han Kwon; Hyung-Ki Hong; Dong Hyun Yun; Kyuchung Lee; Sung-Tae Kim; Young-Hoon Roh; Byung-Hoon Lee

    1995-01-01

    We have investigated the sensing properties of Al2O3-doped ZnO for combustion control in lean-burn conditions. Planar-type sensing elements made of heater, electrode and sensing layer were formed on an alumina substrate using a screen-printing technique. Our exhaust-gas sensor exhibits significant resistance changes even under lean conditions, apparently due to the simultaneous functioning of bulk and surface conduction mechanisms. Utilizing the

  10. Space Station Freedom combustion research

    NASA Technical Reports Server (NTRS)

    Faeth, G. M.

    1992-01-01

    Extended operations in microgravity, on board spacecraft like Space Station Freedom, provide both unusual opportunities and unusual challenges for combustion science. On the one hand, eliminating the intrusion of buoyancy provides a valuable new perspective for fundamental studies of combustion phenomena. On the other hand, however, the absence of buoyancy creates new hazards of fires and explosions that must be understood to assure safe manned space activities. These considerations - and the relevance of combustion science to problems of pollutants, energy utilization, waste incineration, power and propulsion systems, and fire and explosion hazards, among others - provide strong motivation for microgravity combustion research. The intrusion of buoyancy is a greater impediment to fundamental combustion studies than to most other areas of science. Combustion intrinsically heats gases with the resulting buoyant motion at normal gravity either preventing or vastly complicating measurements. Perversely, this limitation is most evident for fundamental laboratory experiments; few practical combustion phenomena are significantly affected by buoyancy. Thus, we have never observed the most fundamental combustion phenomena - laminar premixed and diffusion flames, heterogeneous flames of particles and surfaces, low-speed turbulent flames, etc. - without substantial buoyant disturbances. This precludes rational merging of theory, where buoyancy is of little interest, and experiments, that always are contaminated by buoyancy, which is the traditional path for developing most areas of science. The current microgravity combustion program seeks to rectify this deficiency using both ground-based and space-based facilities, with experiments involving space-based facilities including: laminar premixed flames, soot processes in laminar jet diffusion flames, structure of laminar and turbulent jet diffusion flames, solid surface combustion, one-dimensional smoldering, ignition and flame 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.

  11. Combustion Control 

    E-print Network

    Riccardi, R. C.

    1984-01-01

    . There are many opportunities to improve combustion system efficiency. However, there is no single correct way to maximize efficiency. Each technique must be evaluated and compared before a final selection is made. You have a choice of many energy saving systems...

  12. Preparation and characterization of nano- and non-nanoscale Co?O? spinels obtained from different methods and study of their performance in combustion of aromatics from polluted air-A comparison with Pt/?-Al?O? 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/?-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/?-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

  13. 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…

  14. Combustion Assisted Gravity Drainage (CAGD): An In-Situ Combustion Method to Recover Heavy Oil and Bitumen from Geologic Formations using a Horizontal Injector/Producer Pair

    E-print Network

    Rahnema, Hamid

    2012-11-21

    depleted. The CAGD process combines the advantages of both gravity drainage and conventional in-situ combustion (ISC). A combustion chamber develops in a wide area in the reservoir around the horizontal injector and consists of flue gases, injected air...

  15. 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...

  16. 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...

  17. Internal combustion engine with rotary combustion chamber

    SciTech Connect

    Hansen, C.N.; Cross, P.C.

    1986-09-23

    This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means has an air and fuel intake passage, and exhaust gas passage, a rotary valve assembly operatively associated with the head means for controlling the flow of air and fuel into the rotary valve assembly and piston chamber and the flow of exhaust gas from rotary valve assembly and the piston chamber. The means has a housing with a bore open to the piston chamber accommodating the rotary valve assembly, the valve assembly comprising a cylindrical sleeve located in the bore, the sleeve having an inner surface, an ignition hole, and intake and exhaust ports aligned with the intake passage and exhaust gas passage, spark generating means mounted on the housing operable to generate a spark. The rotatable valving means is located within the sleeve for controlling the flow of air and fuel into the rotary valve assembly and piston chamber and the flow of exhaust gases out of the rotary valve assembly and piston chamber.

  18. Primary zone air proportioner

    DOEpatents

    Cleary, Edward N. G. (San Diego, CA)

    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.

  19. Compound internal combustion and external combustion engine

    Microsoft Academic Search

    Marttila

    1986-01-01

    A compound engine is described comprising at least one internal combustion cylinder having an inlet and an outlet and one external combustion cylinder having an inlet and an outlet, each of the combustion cylinders having a reciprocable piston therein coupled to a common utilization output shaft, heat exchanger means associated with the external combustion cylinder for transferring heat to a

  20. The complementarity of PIXE and synchrotron induced X-ray methods for the characterisation of combustion sources contributing to urban air pollution

    NASA Astrophysics Data System (ADS)

    Cohen, David D.; Siegele, Rainer; Stelcer, Ed; Garton, David; Stampfl, Anton; Cai, Z.; Ilinski, P.; Rodrigues, W.; Legnini, D. G.; Yun, W.; Lai, B.

    2002-04-01

    Current knowledge of fine-particle airborne pollution concentrations and constituents with diameters below 2.5 ?m (PM2.5) is limited. Sources are both natural and man-made. Here we describe two types of experiments performed using the advanced photon source facility at Chicago, and compare the results with PIXE analysis on the same fine particle filters. These are firstly broad beam (2 mm) studies with tuned synchrotron beam energies to help resolve over-lapping X-rays, and secondly highly focused X-ray beam studies (0.2 ?m) of individual fine particles from airborne pollution combustion sources.

  1. Method and device for forming mixture gas in direct injection type internal combustion engine

    Microsoft Academic Search

    A. Saito; M. Yamada; K. Imai; K. Kawamura; M. Kimura

    1987-01-01

    A mixture gas formation method is described for a direct fuel injection type internal combustion engine having a piston with a recess forming a combustion space, air intake means with swirling means for swirling intake air to be supplied to the combustion space, and an intermittent type swirl injection nozzle having at least one tangential passage for swirling fuel, for

  2. Supersonic combustion

    NASA Astrophysics Data System (ADS)

    Gamba, Mirko

    2013-11-01

    Combustion in the supersonic regime presents several challenges over what the low-speed counterpart admits. Here we will review some of these challenges, and we will describe some of the key features of one of the canonical flow fields in supersonic combustion: the reacting transverse jet in a supersonic crossflow (JISCF). From a practical standpoint, the key challenges that limit our control of this combustion regime are fast mixing, robust flame holding and stability. In turn, these aspects are controlled by the complex effects introduced by chemistry, compressibility, shocks and shock/flow interactions, turbulence and the underlying coupling among them. Some of their properties will be discussed here. In particular, for a JISCF in a Mach 2.4 high enthalpy crossflow, the reaction zone structure, its dependence on near-wall events, boundary layer, and shock/boundary layer interaction will be described. We will demonstrate the paramount importance of the coupling between boundary layers and compressibility to provide mechanisms for flame stabilization at the wall. Mixing characteristics, overall structure, and the link to global parameters (momentum flux, velocity and density ratios) that characterize the JISCF, and possibly free shear supersonic flows in general, will also be highlighted from non-reacting experiments. Combustion in the supersonic regime presents several challenges over what the low-speed counterpart admits. Here we will review some of these challenges, and we will describe some of the key features of one of the canonical flow fields in supersonic combustion: the reacting transverse jet in a supersonic crossflow (JISCF). From a practical standpoint, the key challenges that limit our control of this combustion regime are fast mixing, robust flame holding and stability. In turn, these aspects are controlled by the complex effects introduced by chemistry, compressibility, shocks and shock/flow interactions, turbulence and the underlying coupling among them. Some of their properties will be discussed here. In particular, for a JISCF in a Mach 2.4 high enthalpy crossflow, the reaction zone structure, its dependence on near-wall events, boundary layer, and shock/boundary layer interaction will be described. We will demonstrate the paramount importance of the coupling between boundary layers and compressibility to provide mechanisms for flame stabilization at the wall. Mixing characteristics, overall structure, and the link to global parameters (momentum flux, velocity and density ratios) that characterize the JISCF, and possibly free shear supersonic flows in general, will also be highlighted from non-reacting experiments. Sponsored by DoE PSAAP at Stanford University.

  3. 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.

  4. Combustion in porous media

    SciTech Connect

    Dillon, J. [California Inst. of Technology, CA (US)

    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.

  5. Advanced Combustion

    SciTech Connect

    Holcomb, Gordon R. [NETL

    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).

  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. Emissions, combustion dynamics, and control of a multiple swirl combustor

    NASA Astrophysics Data System (ADS)

    Li, Guoqiang

    To achieve single digit NOx emission from gas turbine combustors and prevent the combustion dynamics encountered in Lean Premixed Combustion, it is essential to understand the correlations among emission characteristics, combustion dynamics, and dynamics and characteristics of swirling flow field. The focus of this dissertation is to investigate the emission characteristics and combustion dynamics of multiple swirl dump combustors either in premixing or non-premixed combustion (e.g. Lean Direct Injection), and correlate these combustion characteristics (emissions, combustion instability and lean flammability) to the fluids dynamics (flow structures and its evolution). This study covers measurement of velocity flow field, temperature field, and combustion under effects of various parameters, including inlet flow Reynolds number, inlet air temperature, swirl configurations, downstream exhaust nozzle contraction ratios, length of mixing tube. These parameters are tested in both liquid and gaseous fuel combustions. Knowledge obtained through this comprehensive study is applied to passive and active controls for improving gas turbine combustion performance in the aid of novel sensor and actuator technologies. Emissions and combustion characteristics are shown closely related to the shape and size of central recirculation zone (CRZ), the mean and turbulence velocity and strain rate, and dynamics of large vortical structures. The passive controls, mostly geometry factors, affect the combustion characteristics and emissions through their influences on flow fields, and consequently temperature and radical fields. Air assist, which is used to adjust the momentum of fuel spray, is effective in reducing NOx and depress combustion oscillation without hurting LBO. Fuel distribution/split is also one important factor for achieving low NOx emission and control of combustion dynamics. The dynamics of combustion, including flame oscillations close to LBO and acoustic combustion instability, can be characterized by OH*/CH* radical oscillations and phase-locked chemiluminescence imaging. The periodic fluctuation of jet velocity and formation of large vortical structures within CRZ are responsible for combustion instability in multiple swirl combustors.

  8. Tuned intake air system for a rotary engine

    SciTech Connect

    Corbett, W.D.

    1992-06-09

    This patent describes a rotary internal combustion engine for an outboard board motor. It comprises a plenum chamber attached to the rear of the engine; and the plenum chamber including an inner wall attached to the exhaust manifold; an inlet conduit connecting the cooling air exit passage and the inlet air opening; an outlet conduit connecting the outlet air opening and the combustion air inlet; and the outlet conduit terminating in a combustion air outlet in the inner wall of the plenum chamber.

  9. In situ investigation of laser-induced ignition and the early stages of methane-air combustion at high pressures using a rapidly tuned diode laser at 2.55 microm.

    PubMed

    Lackner, Maximilian; Forsich, Christian; Winter, Franz; Kopecek, Herbert; Wintner, Ernst

    2003-11-01

    The laser-induced ignition of methane/air-mixtures at elevated pressures was investigated by an absorption spectroscopic technique. A room temperature continuous wave InGaAsSb/AlGaAsSb quantum well ridge diode laser was wavelength tuned around 2.55 mum by periodically modulating the injection current from 0 to 174 mA at a 5 kHz repetition rate. The laser heat sink temperature was fixed at 291 K. The infrared laser beam was sent through the pressurized combustion vessel perpendicularly to the igniting laser beam (Nd:YAG laser, 10 ns pulse duration, 20 mJ) at the position of the ignition spark. Fuel-rich to fuel-lean mixtures of methane/air (air equivalence ratio 0.89, 1.06, 1.42, 2.50) were investigated at initial pressures of up to 3 MPa. The initial temperature was 473 K, the volume of the combustion vessel 0.9x10(-3) m(3). The formation of water vapor in the vicinity of the laser spark was tracked by the diode laser. The time resolution of the measurements was 0.2 ms for a total continuous measurement time of up to 1 s. In this way, the laser-induced ignition and its accompanying effects could be investigated on a time scale spanning four orders of magnitude. Apart from the absorbance of water vapor which could be determined semi-quantitatively (due to the effects of severe pressure broadening at high pressures and the ignorance of the exact temperature distribution after ignition), the emissions from the flame (broadband, 1-10 mum) and a gas inhomogeneity index were recorded. The gas inhomogeneity index was obtained by extracting a frequency variable from the time-dependent fluctuations of the transmitted laser intensities and calculating its derivation. The absorbance of water vapor, the emissions from the flame and the gas inhomogeneity index were found to be a powerful tool to characterize laser-induced ignition. Major implications of in situ species concentration measurements at high pressures for the design and development of high-load combustors are presented. PMID:14583276

  10. Dynamic stability, blowoff, and flame characteristics of oxy-fuel combustion

    E-print Network

    Shroll, Andrew Philip

    2011-01-01

    Oxy-fuel combustion is a promising technology to implement carbon capture and sequestration for energy conversion to electricity in power plants that burn fossil fuels. In oxy-fuel combustion, air separation is used to ...

  11. Treating chemistry in combustion with detailed mechanisms -- In situ adaptive tabulation in principal directions -- Premixed combustion

    SciTech Connect

    Yang, B.; Pope, S.B. [Cornell Univ., Ithaca, NY (United States). Sibley School of Mechanical Aerospace Engineering] [Cornell Univ., Ithaca, NY (United States). Sibley School of Mechanical Aerospace Engineering

    1998-01-01

    A new method to treat chemical reactions in combustion problems with detailed mechanisms is developed. The method is called in situ adaptive tabulation in principal directions (ISATPD). The tabulation is done in situ during combustion calculations and is made in the first few principal directions of the composition space. The integration of the governing equations of chemical reactions is made using detailed mechanisms. Test calculations of the premixed pairwise mixing stirred reactor (PPMSR) are performed for methane/air combustion with a skeletal mechanism consisting of 16 species and 40 reactions, and for natural gas combustion with the GRI 2.11 mechanism consisting of 49 species and 279 reactions. Results show that this method has excellent accuracy (for all species) and efficiency. A speedup in performing chemistry of 1,665 is obtained for the methane/air combustion system with the skeletal mechanism. The speedup will increase as the calculation continues since less integrations will be performed.

  12. 66 FR 36836 - National Emission Standards for Hazardous Air Pollutants: Integrated Iron and Steel Manufacturing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2001-07-13

    ...design that suppresses combustion, and an open hood design that promotes combustion. A closed hood fits snugly...open hood design allows combustion air to be drawn into the...sperm count in men and spontaneous abortions in women,...

  13. 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.

  14. An Investigation of Gas Combustion in a Narrow Tube

    Microsoft Academic Search

    V. V. ZAMASHCHIKOV

    2001-01-01

    The specific features of combustion-wave propagation in a narrow tube have been studied experimentally in low-velocity regime for propane-air and hydrogen-air mixtures. For propane mixtures, an increase in the curvature of a flame surface correlates with the displacement of the laminar burning velocity maximum to the region of enriched mixtures. The combustion of lean hydrogen-air mixtures is accompanied by acoustic

  15. 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.

  16. 31st JANNAF Combustion Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Gannaway, Mary T. (editor)

    1994-01-01

    This volume, the first of our volumes, is a collection of 32 unclassified/unlimited papers which were presented at the 31st Joint Army-Navy-NASA-Air Force (JANNAF) Combustion Subcommittee Meeting in conjunction with the Exhaust Plume Technology Subcommittee and SPIRITS User Group Meeting held 17-21 October 1994 at the Lockheed Missiles and Space Company, Sunnyvale, California. Specific subjects discussed include: combustion characteristics of metallized solids in nozzles and plumes; airbreathing propulsion; advanced and electrothermal-chemical guns; gun propellant ignition and interior ballistics; liquid propellant guns; liquid propellant combustion and combustion oscillation and liquid rocket engine combustion.

  17. Aerodynamics and combustion of axial swirlers

    Microsoft Academic Search

    Yongqiang Fu

    2008-01-01

    A multipoint lean direct injection (LDI) concept was introduced recently in non-premixed combustion to obtain both low NOx emissions and good combustion stability. In this concept, a key feature is the injection of finely atomized fuel into the high-swirling airflow at the combustor dome that provides a homogenous, lean fuel-air mixture. In order to achieve the fine atomization and mixing

  18. Dual fuel system for internal combustion engine

    SciTech Connect

    Haman, D.F.; Needham, D.M.

    1989-06-06

    An internal combustion engine is described comprising a crankcase, a cylinder extending from the crankcase and defining a combustion chamber having an inlet port, a transfer passage communicating between the crankcase and the inlet port, a carburetor having an air induction passage communicating with the crankcase and including a venturi and a float bowl adapted to contain fuel for normal operation, a throttle valve intermediate the venturi and the crankcase.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. Sensing combustion intermediates by femtosecond filament excitation.

    PubMed

    Li, He-Long; Xu, Huai-Liang; Yang, Bo-Si; Chen, Qi-Dai; Zhang, Tao; Sun, Hong-Bo

    2013-04-15

    Simultaneous monitoring of multiple combustion intermediates using femtosecond filament-induced nonlinear spectroscopy is demonstrated. Clean fluorescence emissions from free radicals CH, CN, NH, OH, and C(2), as well as atomic C and H, are observed when a femtosecond filament is formed in the laminar ethanol/air flame on an alcohol burner. The fluorescence signals of these species are found to vary as functions of the position of interaction of the filament with the flame along the vertical axis of the central combusting flow, opening up a possibility for remote combustion diagnostic in engines by the excitation of femtosecond laser filament. PMID:23595448

  4. Combustion system for internal combustion engines

    Microsoft Academic Search

    I. Matsuno; H. Yamazoe

    1981-01-01

    A combustion system for internal combustion engines having an exhaust gas recirculating system which is operable by a lean airfuel mixture without aggravation of the combustion. The piston of the engine has a sub-piston projecting on the top thereof and the cylinder head is formed with a recess into which the sub-piston is insertable at a position near the top

  5. Combustion device of an internal combustion engine

    Microsoft Academic Search

    Okuma

    1986-01-01

    A combustion device of an internal combustion engine is described which consists of: a cylinder, a cylinder head closing one end of the cylinder; and a piston reciprocable in the cylinder; the head and piston having stepped portions adapted to interfit as the piston approaches the head so as to define a compression chamber, and a combustion chamber of greater

  6. Reciprocating internal combustion engine with continuous combustion

    Microsoft Academic Search

    Vogelsang

    1976-01-01

    The design of a reciprocating internal combustion engine having a continuous combustion is given. The combustion chamber must be connected with the cylinders of the engine by suitable transfer ports for supplying the gaseous medium to the cylinders and for discharging the burned mixture. In order to obtain a high efficiency, the transfer ports should be as short as possible.

  7. 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.

  8. 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.

  9. Analysis of the potential effects of air pollutants emitted during coal combustion on yellow poplar and loblolly pine and influences on mycorrhizal associations of loblolly pine

    SciTech Connect

    Mahoney, M.J.

    1982-01-01

    Yellow poplar (Liriodendron tulipifera L.) and loblolly pine (Pinus taeda L.), families 2-8 and 540, seedlings were fumigated with 0.07 ppm ozone, 0.06 ppm sulfur dioxide, 0.07 ppm ozone + 0.06 ppm sulfur dioxide, 0.06 ppm sulfur dioxide + 0.10 ppm nitrogen dioxide and 0.07 ppm ozone + 0.06 ppm sulfur dioxide + 0.10 ppm nitrogen dioxide for 35 consecutive days, 6 hr/day. Control seedlings received charcoal-filtered air. Ozone or sulfur dioxide did not significantly affect height growth or dry weight of yellow poplar seedlings. All other treatments significantly reduced height growth and dry weight after 2 weeks of fumigation. Root dry weight was found to be a more sensitive indicator of air pollution stress than either shoot dry weight, height growth or visible symptoms. Loblolly pine seedlings, nonmycorrhizal and mycorrhizal with Pisolithus tinctorius, were fumigated with 0.07 ppm ozone and 0.06 ppm sulfur dioxide singly and in combination, 6 hr/day, for 35 consecutive days. Height growth of mycorrhizal and nonmycorrhizol seedlings was not affected by fumigation. Root dry weight of nonmycorrhizal seedlings was significantly reduced by all pollutant treatments in two replicate experiments. A similar reduction in root dry weight of mycorrhizal seedlings did not occur. Shoot dry weight of nonmycorrhizal seedlings was reduced in four of six pollutant treatments, and in one of six treatments of mycorrhizal seedlings. Mycorrhizal formation was extensive regardless of treatment. Apparent photosynthesis, measured every 4 days, was variable and significant differences among treatments did not occur. Total reducing sugar concentrations of roots were an inconclusive indicator of air pollutant stress.

  10. Catalytic combustion of residual fuels

    NASA Astrophysics Data System (ADS)

    Bulzan, D. L.; Tacina, R. R.

    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.

  11. Investigation Of Synergistic NOx Reduction From Cofiring And Air Staged Combustion Of Coal And Low Ash Dairy Biomass In A 30 Kilowatt Low NOx Furnace 

    E-print Network

    Lawrence, Benjamin Daniel

    2013-08-01

    ............... 52 4.8 Picture of the Furnace Interior after the Arm Staging Modification .. 53 5.1 NOx and CO Results from Natural Gas Experiments ......................... 59 5.2 Primary Air in m3/Min...) be reduced to less than 150 ?g/m3. Total suspended particles in feedlot dust can range from 150 ?g/m3 to 400 ?g/m3 (Sweeten, 1979). Cattle manure is the product of undigested feed and can be used as a fuel by mixing it with coal and firing...

  12. Characterizing fuels for atmospheric fluidized bed combustion

    SciTech Connect

    Marban, G.; Pis, J.J.; Fuertes, A.B. [CSIC, Oviedo (Spain). Instituto Nacional del Carbon] [CSIC, Oviedo (Spain). Instituto Nacional del Carbon

    1995-10-01

    A complete methodology for characterizing coal combustion in atmospheric fluidized bed reactors is presented. The methodology comprises studies of fragmentation and particle size variations during combustion, necessary to allow an accurate determination of kinetic parameters and attrition rates. Samples of three different carbonaceous materials (a medium-ash lignite, a medium-ash anthracite and a graphite) were pyrolyzed in N{sub 2} and partially burned in air in a bench-scale fluidized bed reactor at different operating conditions. The particle size distribution, apparent density and number of particles were evaluated by Image Analysis. Additionally, the sphericity factors were calculated. Combustion studies were carried out in batch experiments in the laboratory-scale, fluidized bed reactor at the same operating conditions. The reactor outlet concentrations of O{sub 2}, CO{sub 2}, and CO were monitored continuously. The results indicate that only anthracite particles experienced both primary (due to devolatilization) and secondary (during char combustion) fragmentation. Graphite particles underwent secondary fragmentation, whereas lignite particles did not significantly vary in number during combustion. Size and density variations during combustion suggest that graphite particles burn under regime II, interparticle diffusion being the rate controlling step. On the other hand, anthracite and lignite particles developed an ash layer, which may control combustion. The attrition constants of the medium-ash materials (lignite and anthracite) were found to be very low whereas that of graphite was much higher due mainly to peripheral percolation during combustion.

  13. Mechanism and kinetics of the formation of no\\/sub x\\/ and other combustion pollutants. Phase I. Unmodified combustion. Final report Apr 73Feb 74

    Microsoft Academic Search

    V. S. Engleman; W. Bartok

    1976-01-01

    The report gives Phase I results of an investigation of the mechanisms and kinetics of the formation of NO\\/sub x\\/ and other combustion pollutants. It gives results of experimental investigations of unmodified combustion and supporting theoretical calculations. The combustion of hydrogen, carbon monoxide, methane, and propane with air in a jet-stirred combustor (JSC) was studied to facilitate the assessment of

  14. 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.

  15. Combustion of coffee husks

    Microsoft Academic Search

    M Saenger; E.-U Hartge; J Werther; T Ogada; Z Siagi

    2001-01-01

    Combustion mechanisms of two types of coffee husks have been studied using single particle combustion techniques as well as combustion in a pilot-scale fluidised bed facility (FBC), 150 mm in diameter and 9 m high. Through measurements of weight-loss and particle temperatures, the processes of drying, devolatilisation and combustion of coffee husks were studied. Axial temperature profiles in the FBC

  16. Combustion fundamentals and applications

    SciTech Connect

    Not Available

    1987-01-01

    These proceedings collect papers given at a meeting on combustion kinetics. Topics include: Effects of piston bowl geometry on combustion characteristics of diesel engines, bipropellant combustion, coal char reactivity, sulfur and nitrogen-oxide emissions, mineral matter in coal and wood, methane, liquid fuels, and carbon particle combustion.

  17. 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.

  18. Health effects of air pollution due to coal combustion in the Chestnut Ridge region of Pennsylvania: cross-section survey of children.

    PubMed

    Schenker, M B; Vedal, S; Batterman, S; Samet, J; Speizer, F E

    1986-01-01

    A cross-sectional study of 4,071 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 (SO2). 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 SO2. However, the highest exposure categories were only slightly above the present annual and 24-hr National Air Quality Standards for SO2. 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. PMID:3487290

  19. 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.

  20. Proceedings of the Combustion Institute, Volume 29, 2002/pp. 909916 DEVELOPMENT OF A MICROREACTOR AS A THERMAL SOURCE FOR

    E-print Network

    Aksay, Ilhan A.

    and combustion products and wall surface contact of the flow through the microreactor body. Self909 Proceedings of the Combustion Institute, Volume 29, 2002/pp. 909­916 DEVELOPMENT-sustained combustion of hydrogen and air mixtures was demonstrated over a wide range of fuel/air mixtures and flow

  1. Plasma igniter for internal combustion engine

    NASA Technical Reports Server (NTRS)

    Fitzgerald, D. J.; Breshears, R. R. (inventors)

    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.

  2. Exhaust gas cleaning device for internal combustion engines

    Microsoft Academic Search

    Y. Sakurai; S. Irimajiri

    1976-01-01

    An internal-combustion spark-ignition V-8 piston engine has an exhaust gas reaction chamber body positioned between its two banks of cylinders. Each cylinder has a main combustion chamber communicating with an auxiliary combustion chamber by means of a torch opening. A main intake manifold with branching portion over the reaction chamber communicates with main intake passages to supply a lean air-fuel

  3. 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.

  4. 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.

  5. Combustion instability modeling and analysis

    SciTech Connect

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States); Sheppard, E.J. [Tuskeggee Univ., Tuskegee, AL (United States). Dept. of Aerospace Engineering

    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.

  6. Coal combustion science

    SciTech Connect

    Hardesty, D.R. (ed.); 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.

  7. 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.

  8. 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 ...

  9. Combustion Assisted Gravity Drainage (CAGD): An In-Situ Combustion Method to Recover Heavy Oil and Bitumen from Geologic Formations using a Horizontal Injector/Producer Pair 

    E-print Network

    Rahnema, Hamid

    2012-11-21

    Combustion assisted gravity drainage (CAGD) is an integrated horizontal well air injection process for recovery and upgrading of heavy oil and bitumen from tar sands. Short-distance air injection and direct mobilized oil production are the main...

  10. Air blast atomization using large air flow rates

    Microsoft Academic Search

    G. E. Andrews

    1989-01-01

    The 'jet mix' type interacting shear layer mixing flame stabilizer has been experimentally tested to ascertain combined air blast atomization and fuel\\/air mixing characteristics at gas turbine primary zone design conditions. Air blast atomization performance improves with increasing proportion of combustion airflow use for this purpose. Low Sauter mean diameter (SMD) values were achieved, but the atomization distribution deteriorated with

  11. 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. (and others)

    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.

  12. Reference guideline for industrial boiler manufacturers to control pollution with combustion modification. Final report Jun 73Sep 77

    Microsoft Academic Search

    G. A. Cato; K. L. Maloney; J. G. Sotter

    1977-01-01

    The report describes combustion modification methods that are available to boiler manufacturers for controlling air pollutant emissions from industrial size fossil-fuel-fired steam boilers. The methods discussed include reduction of excess air, staged combustion, air register adjustment, fuel oil atomization, combustion air temperature adjustment, flue gas recirculation, burner heat release rate, fuel type, burner tune-up, and ammonia injection. The report summarizes

  13. 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…

  14. The Comparison of a convectional TBK-Combustion to Oxyfuel TBK Combustion based on investigations into Nitrogen Oxide (NO) formation and respectively the reduction reactions in a 50 kW Pulverized Coal Combustion Test Facility

    Microsoft Academic Search

    R. Wilhelm; S. Weigl; M. Beckmann

    This article describes the main differences between NO production by conventional air combustion and by the oxyfuel process. The article shows the impact of nitrogen contained both in the air and in the coal for NO production in connection with the process temperature and recirculation ratio based on results of research at a 50 kW Oxyfuel combustion facility and computer

  15. 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...

  16. Experimental and numerical modeling study of engine combustion

    Microsoft Academic Search

    E. L. Chau; D. A. Rotman; F. W. Schipperrijn; A. K. Oppenheim; R. F. Sawyer; A. Iiyama; L. Q. Xia

    1987-01-01

    Square piston engine simulator experiments reveal flame kernel development and flame propagation for single event combustion. High speed color and black and white schlieren cinematography provide time and space resolved records for the combustion of intake manifold injected isopentane with air at a compression ratio of 6.6 to 1, engine speed of 900 rpm, spark and plasma ignition, and flat

  17. Investigation of gasification chemical looping combustion combined cycle performance

    Microsoft Academic Search

    Wenguo Xiang; Sha Wang; Tengteng Di

    2008-01-01

    A novel combined cycle based on coal gasification and chemical looping combustion (CLC) offers a possibility of both high net power efficiency and separation of the greenhouse gas CO. The technique involves the use of a metal oxide as an oxygen carrier, which transfers oxygen from the combustion air to the fuel, and the avoidance of direct contact between fuel

  18. Control of flame configuration and combustion performance in industrial furnaces

    Microsoft Academic Search

    C. Presser; Y. Goldman; J. B. Greenberg; Y. M. Timnat

    1980-01-01

    The influence of geometric and kinematic factors on combustion performance is studied in a liquid fuelled furnace, experimentally and theoretically. By varying the spray axial location, it is possible to produce a more uniform air\\/fuel distribution with an apparent shortening and widening of the flame shape. Increasing the swirl number enhances turbulent mixing, creating a shorter flame in the combustion

  19. Biodesulfurization of coals of different rank: Effect on combustion behavior

    Microsoft Academic Search

    F. Rubiera; A. Arenillas; E. Fuente; J. J. Pis; O. Marteinz; A. Moran

    1999-01-01

    The emission of sulfur oxides during the combustion of coal is one of the causes, among other air pollution problems, of acid rain. The contribution of coal as the mainstay of power production will be determined by whether its environmental performance is equal or superior to other supply options. In this context, desulfurization of coal before combustion by biological methods

  20. 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 from the experimental component of the research was that hydrates can burn completely, and that they burn most rapidly just after ignition and then burn steadily when some of the water in the dissociated zone is allowed to drain away. Excessive surfactant in the water creates a foam layer around the hydrate that acts as an insulator. The layer prevents sufficient heat flux from reaching the hydrate surface below the foam to release additional methane and the hydrate flame extinguishes. No self-healing or ice-freezing processes were observed in any of the combustion experiments. There is some variability, but a typical hydrate flame is receiving between one and two moles of water vapor from the liquid dissociated zone of the hydrate for each mole of methane it receives from the dissociating solid region. This limits the flame temperature to approximately 1800 K. In the theoretical portion of the study, a physical model using an energy balance from methane combustion was developed to understand the energy transfer between the three phases of gas, liquid and solid during the hydrate burn. Also this study provides an understanding of the different factors impacting the hydrate's continuous burn, such as the amount of water vapor in the flame. The theoretical study revealed how the water layer thickness on the hydrate surface, and its effect on the temperature gradient through the dissociated zone, plays a significant role in the hydrate dissociation rate and methane release rate. Motivated by the above mentioned observation from the theoretical analysis, a 1-D two-phase numerical simulation based on a moving front model for hydrate dissociation from a thermal source was developed. This model was focused on the dynamic growth of the dissociated zone and its effect on the dissociation rate. The model indicated that the rate of hydrate dissociation with a thermal source is a function of the dissociated zone thickness. It shows that in order for a continuous dissociation and methane release, some of the water from the dissociated zone needs to be drained. The results

  1. A combustion setup to precisely reference ?13C and ?2H isotope ratios of pure CH4 to produce isotope reference gases of ?13C-CH4 in synthetic air

    NASA Astrophysics Data System (ADS)

    Sperlich, P.; Guillevic, M.; Buizert, C.; Jenk, T. M.; Sapart, C. J.; Schaefer, H.; Blunier, T.

    2012-05-01

    Isotope records of atmospheric CH4 can be used to infer changes in the biochemistry of CH4. One factor limiting quantitative estimates of changes in the biogeochemistry of CH4 are the uncertainties of the isotope measurements due to the lack of a unique isotope reference gas, certified for ?13C-CH4 or ?2H-CH4. We present a method to produce isotope reference gases for CH4 in synthetic airs that are precisely anchored to the VPDB and VSMOW scale and contain ?13C-CH4 values typical for the modern and glacial atmosphere. We quantitatively combusted two pure CH4 gases from fossil and biogenic sources and determined the ?13C and ?2H values of the produced CO2 and H2O relative to the VPDB and VSMOW scale within a very small analytical uncertainty of 0.04‰ and 0.7‰, respectively. We found isotope ratios of -39.56‰ and -56.37‰ for ?13C and -170.1‰ and -317.4‰ for ?2H in the fossil and biogenic CH4, respectively. We used both CH4 types as parental gases from which we mixed two filial CH4 gases. Their ?13C was determined to be -42.21‰ and -47.25‰, representing glacial and present atmospheric ?13C-CH4. The ?2H isotope ratios of the filial CH4 gases were found with -193.1‰ and -237.1‰, respectively. Next, we mixed aliquots of the filial CH4 gases with ultrapure N2/O2 (CH4 ≤ 2 ppb) producing two isotope reference gases of synthetic air with CH4 mixing ratios near atmospheric values. We show that our method is reproducible and does not introduce isotopic fractionation for ?13C within the uncertainties of our detection limit (we cannot conclude this for ?2H because our system is currently not prepared for ?2H-CH4 measurements in air samples). The general principle of our method can be applied to produce synthetic isotope reference gases targeting ?2H-CH4 or other gas species.

  2. A combustion setup to precisely reference ?13C and ?2H isotope ratios of pure CH4 to produce isotope reference gases of ?13C-CH4 in synthetic air

    NASA Astrophysics Data System (ADS)

    Sperlich, P.; Guillevic, M.; Buizert, C.; Jenk, T. M.; Sapart, C. J.; Schaefer, H.; Popp, T. J.; Blunier, T.

    2012-09-01

    Isotope records of atmospheric CH4 can be used to infer changes in the biogeochemistry of CH4. One factor currently limiting the quantitative interpretation of such changes are uncertainties in the isotope measurements stemming from the lack of a unique isotope reference gas, certified for ?13C-CH4 or ?2H-CH4. We present a method to produce isotope reference gases for CH4 in synthetic air that are precisely anchored to the VPDB and VSMOW scales and have ?13C-CH4 values typical for the modern and glacial atmosphere. We quantitatively combusted two pure CH4 gases from fossil and biogenic sources and determined the ?13C and ?2H values of the produced CO2 and H2O relative to the VPDB and VSMOW scales within a very small analytical uncertainty of 0.04‰ and 0.7‰, respectively. We found isotope ratios of -39.56‰ and -56.37‰ for ?13C and -170.1‰ and -317.4‰ for ?2H in the fossil and biogenic CH4, respectively. We used both CH4 types as parental gases from which we mixed two filial CH4 gases. Their ?13C was determined to be -42.21‰ and -47.25‰ representing glacial and present atmospheric ?13C-CH4. The ?2H isotope ratios of the filial CH4 gases were found to be -193.1‰ and -237.1‰, respectively. Next, we mixed aliquots of the filial CH4 gases with ultrapure N2/O2 (CH4 ≤ 2 ppb) producing two isotope reference gases of synthetic air with CH4 mixing ratios near atmospheric values. We show that our method is reproducible and does not introduce isotopic fractionation for ?13C within the uncertainties of our detection limit (we cannot conclude this for ?2H because our system is currently not prepared for ?2H-CH4 measurements in air samples). The general principle of our method can be applied to produce synthetic isotope reference gases targeting ?2H-CH4 or other gas species.

  3. Dynamics of reactive systems. Part 2: Heterogeneous combustion and applications; International Colloquium on Dynamics of Explosions and Reactive Systems, 11th, Warsaw, Poland, Aug. 3-7, 1987, Technical Papers

    Microsoft Academic Search

    A. L. Kuhl; J. R. Bowen; J. C. Leyer; A. Borisov

    1988-01-01

    The present conference on the nature of heterogeneous combustion processes and their applications gives attention to topics in the combustion of dust-air mixtures, liquid fuels' combustion, and heterogeneous combustion processes. Among the topics discussed are a novel experimental apparatus for the study of dust-air flames' propagation, turbulent dust combustion in a jet-stirred reactor, an analysis of droplet combustion at supercritical

  4. Process and engine using compression ignition of a homogeneous fuel-air mixture

    Microsoft Academic Search

    Wood

    1988-01-01

    An internal combustion engine is described using compression ignition of an homogeneous gaseous fuel-air mixture comprising, a cylinder having a piston movable therein, air inlet and outlet means connected to the cylinder for admitting fresh air and for exhausting exhaust products therefrom, a combustion chamber connected to the cylinder, a check valve connected between the combustion chamber and a source

  5. Modeling coal combustion behavior in an ironmaking blast furnace raceway: model development and applications

    SciTech Connect

    Maldonado, D.; Austin, P.R.; Zulli, P.; Guo B. [BlueScope Steel Research Laboratories, Port Kembla, NSW (Australia)

    2009-03-15

    A numerical model has been developed and validated for the investigation of coal combustion phenomena under blast furnace operating conditions. The model is fully three-dimensional, with a broad capacity to analyze significant operational and equipment design changes. The model was used in a number of studies, including: Effect of cooling gas type in coaxial lance arrangements. It was found that oxygen cooling improves coal burnout by 7% compared with natural gas cooling under conditions that have the same amount of oxygen enrichment in the hot blast. Effect of coal particle size distribution. It was found that during two similar periods of operation at Port Kembla's BF6, a difference in PCI capability could be attributed to the difference in coal size distribution. Effect of longer tuyeres. Longer tuyeres were installed at Port Kembla's BF5, leading to its reline scheduled for March 2009. The model predicted an increase in blast velocity at the tuyere nose due to the combustion of volatiles within the tuyere, with implications for tuyere pressure drop and PCI capability. Effect of lance tip geometry. A number of alternate designs were studied, with the best-performing designs promoting the dispersion of the coal particles. It was also found that the base case design promoted size segregation of the coal particles, forcing smaller coal particles to one side of the plume, leaving larger coal particles on the other side. 11 refs., 15 figs., 4 tabs.

  6. Combustion Technology Development for an Advanced Glass Melting System

    E-print Network

    Stickler, D. B.; Westra, L.; Woodroffe, J.; Jeong, K. M.; Donaldson, L. W.

    Concept feasibility of an innovative technology for glass production has recently been demonstrated. It is based on suspension heating of the glass-forming batch minerals while entrained in a combustion flow of preheated air and natural gas...

  7. Combustion Technology Development for an Advanced Glass Melting System 

    E-print Network

    Stickler, D. B.; Westra, L.; Woodroffe, J.; Jeong, K. M.; Donaldson, L. W.

    1987-01-01

    Concept feasibility of an innovative technology for glass production has recently been demonstrated. It is based on suspension heating of the glass-forming batch minerals while entrained in a combustion flow of preheated air and natural gas...

  8. SURVEY AND ANALYSIS OF CURRENT EUROPEAN TECHNOLOGIES FOR WOOD COMBUSTION

    EPA Science Inventory

    The report summarizes current technologies and air pollution policies pertaining to wood combustion. Twenty different concepts for wood burning equipment are described. Also included are section diagrams, size ranges, and comments regarding efficiency and convenience. Many of the...

  9. HCCI Combustion Phasing with Closed-Loop Combustion Control Using Variable Compression Ratio in a Multi Cylinder Engine

    Microsoft Academic Search

    Göran Haraldsson; Bengt Johansson; Jari Hyvönen; Saab Automobile Powertrain

    This study applies Closed-Loop Combustion Control (CLCC) using Variable Compression Ratio (VCR) and cylinder balancing using variable lambda to solve the problem. Step changes of set points for combustion phasing, Compression Ratio (CR), and load together with ramps of engine speed and inlet air temperature are investigated. Performances of the controllers are investigated by running the engine at either a

  10. 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.

  11. 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.

  12. Solution Combustion Synthesis Impregnated Layer Combustion Synthesis is a Novel

    E-print Network

    Mukasyan, Alexander

    Solution Combustion Synthesis Impregnated Layer Combustion Synthesis is a Novel Methodology Engineering University of Notre Dame University of Notre Dame #12;Outline: Overview of combustion synthesis Reaction system Combustion front analaysis Theoretical model results Conclusions Acknowledgements #12

  13. Combustion 2000

    SciTech Connect

    None

    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

  14. 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,…

  15. Automatic choke and starting aid for small two-cycle internal combustion engines

    Microsoft Academic Search

    W. A. Scott; M. A. Hutchinson; G. L. Baumbarger

    1992-01-01

    This patent describes a starting aid for a small internal combustion engine having a carburetor, a carburetor bore operatively associated with the carburetor and defining a longitudinal axis, the bore having one end in communication with a source of combustion air and another end of the bore in communication with a piston cylinder of the internal combustion engine. It comprises:

  16. Single free-piston external combustion engine with hydraulic piston detection

    Microsoft Academic Search

    1987-01-01

    An external combustion engine is described comprising: a combustion member including a sleeve having an end closure and an ignition means at each end thereof, inlet and outlet valving means for introducing compressed air and exhausting combusted gases through each end closure, and a free piston mounted in the sleeve for sliding reciprocating axial motion between the end closures and

  17. and reduce emissions in gas turbines by helping to reduce creep in combustion liners

    Microsoft Academic Search

    Hany Rizkalla

    A low-emissions combustion liner is a critical system component for gas turbines. The combustion air in a gas turbine enters through holes in the combustion chamber liner and flows along the liner to keep it cool. Liners are designed to improve durability and cooling while minimizing the flow variation from liner to liner within the same engine. Reducing variation can

  18. ORIGINAL PAPER Fireside Corrosion in Oxy-fuel Combustion of Coal

    E-print Network

    Laughlin, David E.

    ORIGINAL PAPER Fireside Corrosion in Oxy-fuel Combustion of Coal Gordon R. Holcomb · Joseph Tylczak-fuel combustion is burning a fuel in oxygen rather than air for ease of capture of CO2 from for reuse between 10-4 and 10-3 atm of SO3 at 700 °C. Keywords Fireside corrosion Á Oxidation Á Oxy-fuel combustion

  19. 40 CFR 60.2555 - What combustion units are exempt from my State plan?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false What combustion units are exempt from my State plan...of State Plans § 60.2555 What combustion units are exempt from my State plan...excluding the weight of auxiliary fuel and combustion air) of pathological waste,...

  20. Combustion technology developments in power generation in response to environmental challenges

    E-print Network

    Kammen, Daniel M.

    Combustion technology developments in power generation in response to environmental challenges J Abstract Combustion system development in power generation is discussed ranging from the pre-environmental era in which the objectives were complete combustion with a minimum of excess air and the capability

  1. 40 CFR 60.2020 - What combustion units are exempt from this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false What combustion units are exempt from this subpart... Applicability § 60.2020 What combustion units are exempt from this subpart...excluding the weight of auxiliary fuel and combustion air) of pathological waste,...

  2. Influence of combustion parameters on NOx production in an industrial boiler

    E-print Network

    Aldajani, Mansour A.

    Influence of combustion parameters on NOx production in an industrial boiler M.A. Habib a,*, M; accepted 14 April 2007 Available online 24 June 2007 Abstract NOx formation during the combustion process occurs mainly through the oxidation of nitrogen in the combustion air (thermal NOx) and through oxidation

  3. 40 CFR 60.2555 - What combustion units are exempt from my State plan?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false What combustion units are exempt from my State plan...of State Plans § 60.2555 What combustion units are exempt from my State plan...excluding the weight of auxiliary fuel and combustion air) of pathological waste,...

  4. Chemical Looping Combustion - Reduction of nickel oxide\\/nickel aluminate with hydrogen

    Microsoft Academic Search

    Niklas Olsen

    Chemical Looping Combustion (CLC) has been proposed as a power\\/heat generating process with inherent CO2 separation, as the fuel is not combusted in direct contact with nitrogen in the air. In CLC the combustion of fossil fuels is split into separate oxidation and reduction reactions. A reducible metal oxide is cycled between the reactors, and acts as an oxygen carrier.

  5. Circulating fluidized bed combustion in the turbulent regime: Modeling of carbon combustion efficiency and sulfur retention

    SciTech Connect

    Adanez, J.; Gayan, P.; Grasa, G.; Diego, L.F. de; Armesto, L.; Cabanillas, A.

    1999-07-01

    In this work carbon combustion efficiencies and sulfur retentions in CFBC under the turbulent regime were studied. Experimental results were obtained from the combustion of a lignite and an anthracite with a limestone in a CBF pilot plant with 20 cm internal diameter and 6.5 m height. The effect of operating conditions such as coal and limestone particle size distributions, temperature, excess air, air velocity and Ca/S molar ratio on carbon combustion efficiency and sulfur retention was studied. On the other hand, a mathematical model for the carbon combustion efficiencies and sulfur retentions in circulating fluidized bed combustors operating under the turbulent regime was developed. The model has been developed considering the hydrodynamics behavior of a turbulent bed, the kinetics of carbon combustion and sulfur retention in the riser. The hydrodynamics characteristics of the turbulent regime were previously studied in a cold pilot plant and equations to determine the axial and radial voidage in the bed were proposed. A core-annulus structure in the dilute region of the bed was found in this regime. Carbon combustion and sulfur retention were modeled by modifying a model developed for fast beds and taking into account turbulent regime characteristics. The experimental results of carbon combustion efficiencies and sulfur retentions were compared with those predicted by the model and a good correlation was found for all the conditions used.

  6. Fuel control apparatus in internal combustion engine

    SciTech Connect

    Morita, K.; Miyake, J.; Hatanaka, K.; Sakuma, K.

    1988-05-17

    A fuel control apparatus is an internal combustion engine arranged to increase a quantity of fuel supply uniquely determined on the basis of an engine speed and a quantity of suction air by a predetermined quantity upon detection of acceleration of the internal combustion engine is described comprising: a detection means for detecting acceleration and deceleration of the internal combustion engine; an engine speed operation means for calculating the number of engine resolutions; a calculation means for calculating a continuous acceleration correcting factor representing a quantity to be subtracted from the predetermined quantity in accordance with the value of integration of the number of engine revolutions calculated by the engine speed operation means; and a fuel supply means for supplying fuel to the internal combustion engine in accordance with an output of the calculation means.

  7. 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

  8. High efficiency detonation internal combustion engine (DICE)

    NASA Astrophysics Data System (ADS)

    Loth, Eric; Loth, John; Loth, Frank

    1992-07-01

    Controlled detonation combustion could be used in future internal combustion engines to achieve high cycle efficiency and minimize NO(x) formation, if conventional design limitations are removed. An engine is proposed that uses a separate detonation combustion chamber which discharges tangentially into an expansion chamber formed by the piston and cylinder at top dead center. The expansion chamber is designed to efficiently store a portion of the detonation wave's kinetic energy in the form of a vortex, which is subsequently converted into static pressure. The rapid burning, followed by 'leaning' through mixing with air in the vortex chamber, may reduce the formation of NO(x) and unburned hydrocarbons as compared to conventional combustion. The thermodynamic aspects of detonation combustion compared to either constant volume or constant pressure combustion yield a significant increase in combustion compression ratio for fuels such as natural gas. The shock wave propagation through the vortex chamber is described with a shock-capturing finite element Euler flow code supporting the premise of vortex storage and rapid-mixing characteristics.

  9. Low NOx combustion system for heavy oil

    SciTech Connect

    Kurata, Chikatoshi; Sasaki, Hideki

    1999-07-01

    As a result of the increasing demand for white oil as one of countermeasures for pollution control and as a fuel for motor vehicle, coupled with the increasing import of heavy crude oil, heavy oils such as asphalt and distillation residue have become surplus in Japan. It is difficult by the conventional low NOx technology to control the NOx emission from the industrial small and medium capacity boilers, which use heavy oil as their fuels. The authors have been developing and improving NOx control technologies for boilers such as low NOx burners, two-stage combustion methods and so on. They have developed a new combustion system for heavy oil, which generates less NOx and soot than conventional systems, by applying the knowledge, obtained in the course of their development of Coal Partial Combustor (CPC). The conventional low NOx combustion method for oil firing boilers has been developed based on decreasing the flame temperature and delaying the combustion reaction. In the system, however, the heavy oil shall be combusted in the intense reducing atmosphere at the high flame temperature between 1,500 C and 1,600 C, and then the combustions gas shall be cooled and oxidized by two-stage combustion air. With this system, NOx emission can be suppressed below 100ppm (converted as O{sub 2}=4%).

  10. 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).

  11. Economics of the heat pipe air preheater for primary air service

    Microsoft Academic Search

    1984-01-01

    The heat pipe air preheater takes advantage of the high thermal conductance of the heat pipe. This efficient device, unlike conventional rotary regenerative air heaters, permits no leakage between the combustion air and flue gas. Heat pipe air preheaters are currently commercially available in sizes consistent with primary air heater service for large utility steam generators. An evaluation of capital

  12. Air blast atomization as a function of pressure loss for large air flow rates

    Microsoft Academic Search

    G. E. Andrews

    1990-01-01

    Combined air blast atomization and fuel and air mixing was studied in an interacting shear layer jet mixing flame stabilizer, termed Jet Mix, at gas turbine primary zone design conditions. Air blast atomization improves if large proportions of the combustion air flow are used and the maximum possible airflows were used in this study, as all the primary zone air

  13. Fuel supply system for internal-combustion engine

    Microsoft Academic Search

    M. Fujieda; Y. Oyama

    1988-01-01

    This patent describes a fuel supply system for an internal-combustion engine. The fuel supply system consists of: fuel supply means; an intake-air passage connected through an intake valve to a combustion chamber defined by a cylinder and a piston, the intake-air passage having a volume between the fuel supply means and the intake valve means equal to a volume of

  14. Fluidized bed coal combustion reactor

    NASA Technical Reports Server (NTRS)

    Moynihan, P. I.; Young, D. L. (inventors)

    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.

  15. Combustion chamber for an internal-combustion engine

    Microsoft Academic Search

    Ishida

    1987-01-01

    A combustion chamber for an internal-combustion engine is described comprising: a main combustion chamber defined by a first recess in the top surface of the crown of a piston; an auxiliary combustion chamber defined by a second recess in the top surface of the crown of the piston beside the main combustion chamber, the volume of the auxiliary combustion chamber

  16. 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.

  17. Combustion 2000

    SciTech Connect

    None

    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

  18. SOURCE ASSESSMENT: RESIDENTIAL COMBUSTION OF COAL

    EPA Science Inventory

    The report summarizes the assessment of air emissions from the residential combustion of anthracite, bituminous, and lignite coals, with emphasis on bituminous coals. Approximately 2.6 million metric tons of coal were burned as a primary source of heat in an estimated 493,018 hou...

  19. 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...

  20. 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.

  1. ChemTeacher: Combustion

    NSDL National Science Digital Library

    2011-01-01

    ChemTeacher compiles background information, videos, articles, demonstrations, worksheets and activities for high school teachers to use in their classrooms. The Combustion page includes resources for teaching students about the chemistry behind combustion.

  2. Internal combustion engine with dual combustion chambers

    Microsoft Academic Search

    Simay

    1987-01-01

    This patent describes a spark-ignition. The overhead valve type internal combustion engine comprises: a cylinder closed at the top by a semi-spherical cylinder head; a piston reciprocating within the cylinder with the piston; cylinder and cylinder head defining at least one combustion chamber; and wherein the cylinder head includes an intake valve aperture, an exhaust valve aperture, and a spark

  3. Combustion Modeling in Internal Combustion Engines

    Microsoft Academic Search

    FRANK J. ZELEZNIK

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to

  4. Oxy-Combustion Boiler Material Development

    SciTech Connect

    Gagliano, Michael; Seltzer, Andrew; Agarwal, Hans; Robertson, Archie; Wang, Lun

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year) data. The test program details and data are presented herein.

  5. Oxy-Combustion Boiler Material Development

    SciTech Connect

    Michael Gagliano; Andrew Seltzer; Hans Agarwal; Archie Robertson; Lun Wang

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO{sub 2} level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year) data. The test program details and data are presented herein.

  6. Low emission U-fired boiler combustion system

    DOEpatents

    Ake, Terence (North Brookfield, MA); Beittel, Roderick (Worcester, MA); Lisauskas, Robert A. (Shrewsbury, MA); Reicker, Eric (Barre, MA)

    2000-01-01

    At least one main combustion chamber contains at least one pulverized coal burner. Each pulverized coal burner is operatively arranged for minimizing NO.sub.X production and for maintaining a predetermined operating temperature to liquefy ash within the combustion chamber. The combustion chamber includes a slag drain for removing slag from the combustion chamber. A slag screen is positioned in a generally U-shaped furnace flow pattern. The slag screen is positioned between the combustion chamber and a radiant furnace. The radiant furnace includes a reburning zone for in-furnace No.sub.X reduction. The reburning zone extends between a reburning fuel injection source and at least one overfire air injection port for injecting air.

  7. Internal combustion engine apparatus

    SciTech Connect

    Kondo, T.; Inaga, H.

    1986-12-23

    An internal combustion engine apparatus is described comprising, in combination, an internal combustion engine having an ignition system capable of step advance when a predetermined engine speed is reached between low and high ranges of engine speed; and a centrifugal clutch connected to an output shaft of the internal combustion engine, the centrifugal clutch being engaged and disengaged at substantially the predetermined engine speed.

  8. Internal combustion engine

    Microsoft Academic Search

    Amery

    1974-01-01

    A spark ignition internal combustion engine is described that uses a double-headed cylinder to achieve more complete combustion, and hence less unburned exhaust emissions, than existing internal combustion engine designs. The engine is of the piston type, with the piston mechanically arranged for both oscillatory and related vertically reciprocating motion. The cylinder is double-headed, and the heads are oriented with

  9. Internal combustion engine

    Microsoft Academic Search

    Thomas

    1976-01-01

    An internal combustion engine is described which utilizes a combustion cylinder formed in part of material which can withstand high temperatures in conjunction with a displacement or power piston having a ringless section capable of withstanding high temperatures and being backed up by a relatively low temperature lubricated ringed piston section. Means to inject fuel and water into the combustion

  10. Combustion synthesis and nanomaterials

    Microsoft Academic Search

    Singanahally T. Aruna; Alexander S. Mukasyan

    2008-01-01

    The recent developments and trends in combustion science towards the synthesis of nanomaterials are discussed. Different modifications made to conventional combustion approaches for preparation of nanomaterials are critically analyzed. Special attention is paid to various applications of combustion synthesized nanosized products.

  11. Integration of air separation membrane and coalescing filter for use on an inlet air system of an engine

    DOEpatents

    Moncelle, Michael E. (Bloomington, IL)

    2003-01-01

    An intake air separation system suitable for combustion air of an internal combustion engine. An air separation device of the system includes a plurality of fibers, each fiber having a tube with a permeation barrier layer on the outer surface thereof and a coalescing layer on the inner surface thereof, to restrict fluid droplets from contacting the permeation barrier layer.

  12. JANNAF 36th Combustion Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    Volume 1, the first of three volumes is a compilation of 47 unclassified/unlimited-distribution technical papers presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 36th Combustion Subcommittee held jointly with the 24th 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. Solid phase propellant combustion topics covered in this volume include cookoff phenomena in the pre- and post-ignition phases, solid rocket motor and gun propellant combustion, aluminized composite propellant combustion, combustion modeling and combustion instability and instability measurement techniques.

  13. JANNAF 35th Combustion Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    Volume 1, the first of two volumes is a compilation of 63 unclassified/unlimited distribution technical papers presented at the 35th meeting of the Joint Army-Navy-NASA-Air Force (JANNAF) Combustion Subcommittee (CS) held jointly with the 17th Propulsion Systems Hazards Subcommittee (PSHS) and Airbreathing Propulsion Subcommittee (APS). The meeting was held on 7-11 December 1998 at Raytheon Systems Company and the Marriott Hotel, Tucson, AZ. Topics covered include solid gun propellant processing, ignition and combustion, charge concepts, barrel erosion and flash, gun interior ballistics, kinetics and molecular modeling, ETC gun modeling, simulation and diagnostics, and liquid gun propellant combustion; solid rocket motor propellant combustion, combustion instability fundamentals, motor instability, and measurement techniques; and liquid and hybrid rocket combustion.

  14. Optimization of combustion by fuel testing in a NO x reduction test facility

    Microsoft Academic Search

    Gerry J. Hesselmann

    1997-01-01

    Combustion data for a wide range of coals were obtained in a 160 kWth NOx reduction test facility (NRTF). Parametric testing was undertaken under conditions of single-stage combustion, furnace air staging and natural gas reburning. From these tests, detailed information directly applicable to large utility furnaces on the effects of coal characteristics, excess air, stoichiometry and residence time on NOx,

  15. Optimization of burning process of hydrocarbon fuels with varying specific heat of combustion

    NASA Astrophysics Data System (ADS)

    Saifullin, E. R.; Vankov, Yu V.

    2015-06-01

    This article explores the combustion of gaseous fuel in the case of an abrupt change of the specific heat of combustion. Analyzes the changes in the rate of heat when the fuel and air flows are constant. Defines the conditions for which retained the initial rate of heat release and optimal fuel-air ratio.

  16. Identification of biomass co-combustion operating point using image processing

    NASA Astrophysics Data System (ADS)

    Kotyra, Andrzej; Wójcik, Waldemar; Iskakova, Aigul; Zhussupbektov, Sarsenbek

    2014-08-01

    Thermal power and excess air coefficient are one of key parameters that characterize operating point of combustion process. In practice, they are hard to determine directly. The k-nearest neighbor (k-NN) regression algorithm was applied where some flame image geometric parameters were used as predictors. The model was assessed by carrying out several combustion tests for nine different settings of the laboratory combustion facility. Thermal power and excess air coefficient were kept constant and set independently for known biomass content.

  17. Oxygen Fireflooding: Combustion Tube Tests With Light, Medium, and Heavy Crude Oils

    Microsoft Academic Search

    Goutam Shahani; James Hansel

    1987-01-01

    Five light, medium, and heavy crude oils were evaluated in a combustion tube, primarily at 750 and 2,000 psig (5.2 and 13.8 MPa) and with Oâ concentrations between 21 (air) and 95%. The overall characteristics of combustion with Oâ appear to be superior to those with air. For light and medium crude oils, when the combustion are marginal (e.g., at

  18. High-Temperature Corrosion of AlN-Based Composite Ceramic in Air and in Combustion Products of Commercial Fuel. Part 2. Corrosion of Ceramic Composites in the AlN – SiC – TiB 2 System in Air and in Combustion Products of Kerosene and Diesel Fuel

    Microsoft Academic Search

    Vladimir A. Lavrenko; D. J. Baxter; Alla D. Panasyuk; Martina Desmaison-Brut

    2004-01-01

    Corrosion resistance has been examined for composites in the AlN – SiC – TiB2 ternary system. They have high corrosion resistance in air up to 1500°C because mullite and ß-tialite are formed in the outer layer of scale. Their corrosion resistance substantially exceeds that of other ceramic materials because of the formation of the mullite phase on prolonged exposure (up

  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. SAFETY ASPECTS OF OXYGEN AERATION ACTIVATED SLUDGE SYSTEMS

    EPA Science Inventory

    This project was carried out to assess the impact of the use of oxygen and oxygen-enriched air for aeration of activated sludge systems on the safety of municipal waste-water treatment plants and their personnel. The tasks included (1) determination of oxygen combustion hazards f...

  1. Tertiary oil production process

    Microsoft Academic Search

    G. Pusch

    1977-01-01

    The status quo in the field of in situ combustion processes in crude oil reservoirs is demonstrated. Special emphasis is laid on the importance of the combination of water and oxygen injection. A step which points to the future of in situ coal gasification. Initial solutions to the safety problem concerning the use of oxygen or oxygen enriched air in

  2. Analysis of cyclic combustion of the coal-water suspension

    NASA Astrophysics Data System (ADS)

    Kijo-Kleczkowska, Agnieszka

    2011-04-01

    Combustion technology of the coal-water suspension creates a number of new possibilities to organize the combustion process fulfilling contemporary requirements, e.g. in the environment protection. Therefore the in-depth analysis is necessary to examine the technical application of coal as a fuel in the form of suspension. The research undertakes the complex investigations of the continuous coal-water suspension as well as cyclic combustion. The cyclic nature of fuel combustion results from the movement of the loose material in the flow contour of the circulating fluidized bed (CFB): combustion chamber, cyclone and downcomer. The experimental results proved that the cyclic change of oxygen concentration around fuel, led to the vital change of both combustion mechanisms and combustion kinetics. The mathematical model of the process of fuel combustion has been presented. Its original concept is based on the allowance for cyclic changes of concentrations of oxygen around the fuel. It enables the prognosis for change of the surface and the centre temperatures as well as mass loss of the fuel during combustion in air, in the fluidized bed and during the cyclic combustion.

  3. Dust Combustion Safety Issues for Fusion Applications

    SciTech Connect

    L. C. Cadwallader

    2003-05-01

    This report summarizes the results of a safety research task to identify the safety issues and phenomenology of metallic dust fires and explosions that are postulated for fusion experiments. There are a variety of metal dusts that are created by plasma erosion and disruptions within the plasma chamber, as well as normal industrial dusts generated in the more conventional equipment in the balance of plant. For fusion, in-vessel dusts are generally mixtures of several elements; that is, the constituent elements in alloys and the variety of elements used for in-vessel materials. For example, in-vessel dust could be composed of beryllium from a first wall coating, tungsten from a divertor plate, copper from a plasma heating antenna or diagnostic, and perhaps some iron and chromium from the steel vessel wall or titanium and vanadium from the vessel wall. Each of these elements has its own unique combustion characteristics, and mixtures of elements must be evaluated for the mixture’s combustion properties. Issues of particle size, dust temperature, and presence of other combustible materials (i.e., deuterium and tritium) also affect combustion in air. Combustion in other gases has also been investigated to determine if there are safety concerns with “inert” atmospheres, such as nitrogen. Several coolants have also been reviewed to determine if coolant breach into the plasma chamber would enhance the combustion threat; for example, in-vessel steam from a water coolant breach will react with metal dust. The results of this review are presented here.

  4. High-Temperature Corrosion of AlN-Based Composite Ceramic in Air and in Combustion Products of Commercial Fuel. Part 1. Corrosion of Ceramic Composites in the AlN – SiC System in Air and in Combustion Products of Kerosene and Diesel Fuel

    Microsoft Academic Search

    Vladimir A. Lavrenko; D. J. Baxter; Alla D. Panasyuk; Martina Desmaison-Brut

    2004-01-01

    We have established that scale formed upon oxidation of ceramic composites in the AlN – SiC system in air at temperatures up to 1550°C contains mullite 3Al2O3·2SiO2 as the major phase of the outer layer, which provides its high protective properties. The inner layer of the scale contains ß-SiO2, a-Al2O3, and a fairly small amount of the oxynitride Al10N8O2. In

  5. JANNAF Combustion Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    This volume, the first of four volumes, is a collection of 33 unclassified/unlimited papers which were presented at the 33rd Joint Army-Navy-NASA-Air Force (JANNAF) Combustion Subcommittee Meeting in conjunction with the Propulsion Systems Hazards at the Naval Postgraduate School, Monterey, CA. The JANNAF papers contained in this volume review airbreathing combustion measurement, performance and control; electrothermal-chemical gun experiment and modeling; liquid propellant gun experiment and modeling; solid propellant gun interior ballistics; formulation modeling and diagnostics, ignition, and gun barrel wear modeling, blast and flash; and ram, fastcore and gas generator gun propulsion concepts.

  6. Real-time combustion controller

    DOEpatents

    Lindner, Jeffrey S. (Starkville, MS); Shepard, W. Steve (Starkville, MS); Etheridge, John A. (Starkville, MS); Jang, Ping-Rey (Starkville, MS); Gresham, Lawrence L. (Starkville, MS)

    1997-01-01

    A method and system of regulating the air to fuel ratio supplied to a burner to maximize the combustion efficiency. Optical means are provided in close proximity to the burner for directing a beam of radiation from hot gases produced by the burner to a plurality of detectors. Detectors are provided for sensing the concentration of, inter alia, CO, CO.sub.2, and H.sub.2 O. The differences between the ratios of CO to CO.sub.2 and H.sub.2 O to CO are compared with a known control curve based on those ratios for air to fuel ratios ranging from 0.85 to 1.30. The fuel flow is adjusted until the difference between the ratios of CO to CO.sub.2 and H.sub.2 O to CO fall on a desired set point on the control curve.

  7. Real-time combustion controller

    DOEpatents

    Lindner, J.S.; Shepard, W.S.; Etheridge, J.A.; Jang, P.R.; Gresham, L.L.

    1997-02-04

    A method and system are disclosed for regulating the air to fuel ratio supplied to a burner to maximize the combustion efficiency. Optical means are provided in close proximity to the burner for directing a beam of radiation from hot gases produced by the burner to a plurality of detectors. Detectors are provided for sensing the concentration of, inter alia, CO, CO{sub 2}, and H{sub 2}O. The differences between the ratios of CO to CO{sub 2} and H{sub 2}O to CO are compared with a known control curve based on those ratios for air to fuel ratios ranging from 0.85 to 1.30. The fuel flow is adjusted until the difference between the ratios of CO to CO{sub 2} and H{sub 2}O to CO fall on a desired set point on the control curve. 20 figs.

  8. Rotary internal combustion engine

    SciTech Connect

    Wilson, C.E.

    1988-01-05

    An internal combustion engine is described comprising: wall means defining at least one toroidal cylinder; at least one pair of flywheels mounted for rotation with respect to the cylinder around a central axis thereof and with respect to each other; piston means within the cylinder including a first pair of pistons mounted on one of the flywheels at selected locations, and a further pair of pistons mounted on another of the flywheels at selected locations, the pistons cooperating to define with the cylinder compressing/expanding chambers during rotation of the flywheels and the piston attached thereto; means for injecting fuel and inserting air into the compressing chamber through the wall means of the cylinder; means for igniting fuel injected within the cylinder at predetermined times such that the ignited fuel acts against the piston means and causes the piston means to revolve with the cylinder; and means for controlling the mode of operation of the piston means and the flywheels whereby the first and further pairs of pistons revolve in the same direction within the cylinder at varying angular velocities during cycles of the engine.

  9. Combustion chamber system for kerosine internal combustion engine

    Microsoft Academic Search

    S. Yagi; J. Ootani; M. Araki; F. Yoshida

    1986-01-01

    A combustion chamber system is described for an overhead valve type kerosine internal combustion engine, comprising: a cylinder head; a piston slidable in a cylinder; a main combustion chamber defined by a lower surface of a cylinder head and an upper surface of the piston; an auxiliary combustion chamber defined within the cylinder head and spaced from the main combustion

  10. Boiler using combustible fluid

    DOEpatents

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  11. Combustion modeling in internal combustion engines

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  12. Liquid fuel combustion within silicon-carbide coated carbon foam

    SciTech Connect

    Vijaykant, S.; Agrawal, Ajay K. [Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487 (United States)

    2007-10-15

    Combustion of kerosene inside porous inert medium (PIM) has been investigated with the goal of reducing the emissions of nitric oxides (NO{sub x}), carbon monoxide (CO) and soot. Silicon-carbide (SiC) coated carbon foam is used as PIM to attain high structural strength. The two-zone porous burner design consists of preheat and combustion sections. Different PIM configurations were tested by stacking together square porous pieces of 2.5 cm thickness. Two types of fuel injectors are considered: (i) in the air-assist injector, approximately 5% of the combustion air is used for atomization and the remaining air enters as the primary co-flow around the injector, and (ii) in the swirling-air injector, all of the combustion air enters the injector to create a swirling flow around the fuel jet to enhance atomization and fuel-air premixing. The distance between the injector and PIM inlet is a key operational parameter, which was varied in experiments with both injectors over a range of equivalence ratios and heat release rates. The NO{sub x} and CO emissions were measured to optimize the PIM configuration with minimum emissions. Results show stable combustion over a wide operating range. Three combustor operational regimes are identified depending upon the injector location. (author)

  13. Hydrogen-air detonations

    Microsoft Academic Search

    C. M. Guirao; R. Knystautas; J. H. Lee; W. Benedick; M. Berman

    1982-01-01

    The Three Mile Island nuclear plant accident has triggered renewed interest in fundamental combustion studies in hydrogen-air mixtures. The present study is concerned with the problem of detonation of atmospheric, hydrogen-air mixtures and reports new experimental results on cell sizes lambda and critical tube diameters d\\/sub c\\/. The results confirm the empirical correlation d\\/sub c\\/ = 13lambda. Comparison of the

  14. Investigation of fluid-bed combustion of municipal solid waste

    Microsoft Academic Search

    R. H. Eustis; K. B. Wilson; L. C. Preuit; M. M. Marasigan

    2008-01-01

    Air classified Municipal Solid Waste (MSW) was fired in an Atmospheric Fluidized Bed Combustor at low excess air to simulate boiler conditions. The 7 sq ft combustor at Combustion Power Company's energy laboratory in Menlo Park, California, incorporates water tubes for heat extraction and recycles elutriated particles to the bed. System operation was stable while firing processed MSW for the

  15. Identification and idle speed control of internal combustion engines

    Microsoft Academic Search

    G. De Nicolao; C. Rossi; R. Scattolini; M. Suffritti

    1999-01-01

    This paper presents an integrated approach for the identification and control of internal combustion engines in idle-speed conditions. The inputs of the nonlinear identification model are the position of the idle speed air actuation system and the spark advance, while its outputs are the pressure inside the air intake manifold and the crank shaft speed. The estimated model is then

  16. Applications of Power Modulator Technology to Ignition and Combustion

    Microsoft Academic Search

    D. Singleton; C. Cathey; A. Kuthi; M. Gundersen

    2008-01-01

    We report recent studies of applications of power modulator technology to ignition and combustion at USC, in collaboration with the Naval Postgraduate School, the Air Force Research Laboratory at Wright Patterson Air Force Base, and the Nissan Research Center. Transient plasma is under investigation as a technology for ignition of pulse detonation engines and other applications. It is attractive as

  17. Lump wood combustion process

    NASA Astrophysics Data System (ADS)

    Kubesa, Petr; Horák, Ji?í; Branc, Michal; Krpec, Kamil; Hopan, František; Koloni?ný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  18. Coal combustion products

    USGS Publications Warehouse

    Kalyoncu, R.S.; Olson, D.W.

    2001-01-01

    Coal-burning powerplants, which supply more than half of U.S. electricity, also generate coal combustion products, which can be both a resource and a disposal problem. The U.S. Geological Survey collaborates with the American Coal Ash Association in preparing its annual report on coal combustion products. This Fact Sheet answers questions about present and potential uses of coal combustion products.

  19. Indoor air pollution and its health effects in China ? a review

    Microsoft Academic Search

    B. H. Chen; C. J. Hong; X. Z. He

    1992-01-01

    Indoor air pollution in cities in China is mainly from domestic coal combustion, and from coal and biomass fuel combustion in rural areas. Factors affecting indoor air pollutant concentrations include fuel, ventilation, floor plan of house, and season, etc. Pollutants emitted from coal combustion are significantly higher than those from gas or liquefied petroleum gas. Among biofuels used in China,

  20. Combustion under microgravity conditions

    SciTech Connect

    Berlad, A.L.

    1982-01-01

    Reduced gravity combustion experiments are frequently required to provide the information necessary for comprehensive understanding of combustion phenomena at normal gravitational conditions. Previous papers have dealt in detail with a broad range of combustion science experiments which require reduced gravity experimentation. This paper enlarges on these previous studies. Reduced gravity experiments are shown to be needed for comprehensive understanding of kinetic and thermokinetic oscillatory flame processes, the radiative ignition of solids, high pressure flame propagation and extinction phenomena, as well as a number of other combustion science areas of vital interest.