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1

Application of Oxygen Enriched Combustion Air in Radiant Tubes: Feasibility Study. Final Report April 1984-March 1985.  

National Technical Information Service (NTIS)

The objective of the program is to determine the effect of applying oxygen enriched combustion air to radiant tubes. Specifically, the increases in heat transfer rates and thermal efficiency are to be quantified as a function of the oxygen concentration i...

S. R. Huebner R. A. Schmall C. A. Hersch

1985-01-01

2

A hybrid process combining oxygen enriched air combustion and membrane separation for post-combustion carbon dioxide capture  

Microsoft Academic Search

For carbon dioxide capture and storage (CCS), similar to a large majority of industrial processes, the separation (i.e. capture) step dominates the costs of the technological chain. Based on a concept of minimal work of concentration, the evaluation of a tentative capture framework which combines an oxygen enrichment step before combustion and a CO2 capture step from flue gas has

Eric Favre; Roda Bounaceur; Denis Roizard

2009-01-01

3

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

SciTech Connect

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.

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

4

Oxygen-enriched air production for MHD power plants  

SciTech Connect

Direct coal-fired MHD/steam power plants using preheated, oxygen-enriched air offer the near-term potential of attractive power plant efficiencies, operating flexibility, and improved reliability compared to plants with separately-fired or directly-heated air preheaters. Systems analyses of various MHD/steam power plants indicate that maximum plant efficiency is achieved by directly preheating combustion air with high temperature combustion products from the MHD topping cycle. However, difficulties in developing regenerative preheater materials to continuously withstand the corrosive, erosive, and fouling action of hot potassium and slag-laden gases preclude the use of directly-heated high temperature air preheaters in first generation MHD plants. Previously, high power consumption for oxygen production has limited the consideration of oxygen enrichment for MHD application. Therefore, the Magnetohydrodynamics Division of the Department of Energy (DOE/MHD) requested Gilbert Associates, Inc. (GAI) to develop and then analyze information on minimum power requirements and plant costs for oxygen production for a range of oxygen enrichments and delivery pressures. Such information will facilitate evaluation of oxygen-enriched MHD system performance and economics. An analysis of several of the cryogenic air separation process cycle variations and compression schemes that have been designed to minimize net system power requirements for supplying pressurized, oxygen-enriched air to the combustor of a 2000 MWt (coal input) baseload MHD power plant is presented. (WHK)

Not Available

1980-05-01

5

Studies of MHD generator performance with oxygen enriched coal combustion  

NASA Astrophysics Data System (ADS)

This paper presents calculations made using the Aerodyne PACKAGE (Plasma Analysis, Chemical Kinetics, and Generator Efficiency) computer code which bear on two questions which arise in connection with choices between oxygen enrichment and air preheating to attain the high combustion temperatures needed for open-cycle, coal-fired MHD power generation. The first question is which method produces the highest enthalpy extraction per unit channel length. The second is, in test facilities intended to study tradeoffs between oxygen enrichment and preheated air, can good generator performance be obtained from the same physical channel for different combustor compositions. The answer to the first question is found to depend on what combustor conditions are taken to be comparable. As for the second question, it is found that operation with channel input from off-design combustor conditions can cause serious problems, which can be partially alleviated by changing the channel load factors.

Wormhoudt, J.; Yousefian, V.; Kolb, C. E.; Martinez-Sanchez, M.

1980-07-01

6

Long term analysis of the biomass content in the feed of a waste-to-energy plant with oxygen-enriched combustion air.  

PubMed

Thermal utilization of municipal solid waste and commercial wastes has become of increasing importance in European waste management. As waste materials are generally composed of fossil and biogenic materials, a part of the energy generated can be considered as renewable and is thus subsidized in some European countries. Analogously, CO(2) emissions of waste incinerators are only partly accounted for in greenhouse gas inventories. A novel approach for determining these fractions is the so-called balance method. In the present study, the implementation of the balance method on a waste-to-energy plant using oxygen-enriched combustion air was investigated. The findings of the 4-year application indicate on the one hand the general applicability and robustness of the method, and on the other hand the importance of reliable monitoring data. In particular, measured volume flows of the flue gas and the oxygen-enriched combustion air as well as corresponding O(2) and CO(2) contents should regularly be validated. The fraction of renewable (biogenic) energy generated throughout the investigated period amounted to between 27 and 66% for weekly averages, thereby denoting the variation in waste composition over time. The average emission factor of the plant was approximately 45 g CO(2) MJ(-1) energy input or 450 g CO(2) kg(-1) waste incinerated. The maximum error of the final result was about 16% (relative error), which was well above the error (<8%) of the balance method for plants with conventional oxygen supply. PMID:21382872

Fellner, Johann; Cencic, Oliver; Zellinger, Günter; Rechberger, Helmut

2011-03-07

7

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

SciTech Connect

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

Lahiri, D.; Mehta, P.S. [Indian Inst. of Tech., Madras (India); Poola, R.B.; Sekar, R. [Argonne National Lab., IL (United States)

1997-09-01

8

Combustion of coal chars in oxygen-enriched atmospheres  

SciTech Connect

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%.

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

2007-07-01

9

Oxygen-enriched air production for MHD power plants  

NASA Astrophysics Data System (ADS)

An analysis of several of the cryogenic air separation process cycle variations and compression schemes designed to minimize net system power requirements for supplying pressurized, oxygen-enriched air to the combustor of a 2000 MWt (coal input) baseload MHD power plant is presented.

1980-05-01

10

Simulation studies of diesel engine performance with oxygen enriched air and water emulsified fuels  

SciTech Connect

A computer simulation code of a turbocharged, turbocompound diesel engine was modified to study the effects of using oxygen-enriched combustion air and water-emulsified diesel fuels. Oxygen levels of 21 percent to 40 percent by volume in the combustion air were studied. Water content in the fuel was varied from 0 percent to 50 percent mass. Simulation studies and a review and analysis of previous work in this area led to the following conclusions about expected engine performance and emissions: the power density of the engine is significantly increased by oxygen enrichment. Ignition delay and particulate emissions are reduced. Combustion temperatures and No{sub x} emissions are increased with oxygen enrichment but could be brought back to the base levels by introducing water in the fuel. The peak cylinder pressure which increases with the power output level might result in mechanical problems with engine components. Oxygen enrichment also provides an opportunity to use cheaper fuel such as No. 6 diesel fuel. Overall, the adverse effects of oxygen enrichment could be countered by the addition of water and it appears that an optimum combination of water content, oxygen level, and base diesel fuel quality may exist. This could yield improved performance and emissions characteristics compared to a state-of-the-art diesel engine. 9 refs., 8 figs.

Assanis, D.N.; Baker, D. (Illinois Univ., Urbana, IL (USA)); Sekar, R.R.; Siambekos, C.T.; Cole, R.L.; Marciniak, T.J. (Argonne National Lab., IL (USA))

1990-01-01

11

Blast Furnace Operation with Oxygen-Enriched Unheated Blast Air.  

National Technical Information Service (NTIS)

Three trials with oxygen-enriched unheated blast air are described. The trials were conducted in the Bureau of Mines experimental blast furnace located in Bruceton, PA. For the first trial, moisture was added to the oxygenated blast. The second and third ...

P. L. Woolf

1985-01-01

12

Utilizing intake-air oxygen-enrichment technology to reduce cold- phase emissions  

SciTech Connect

Oxygen-enriched combustion is a proven, serious considered technique to reduce exhaust hydrocarbons (HC) and carbon monoxide (CO) emissions from automotive gasoline engines. This paper presents the cold-phase emissions reduction results of using oxygen-enriched intake air containing about 23% and 25% oxygen (by volume) in a vehicle powered by a spark-ignition (SI) engine. Both engineout and converter-out emissions data were collected by following the standard federal test procedure (FTP). Converter-out emissions data were also obtained employing the US Environmental Protection Agency`s (EPA`s) ``Off-Cycle`` test. Test results indicate that the engine-out CO emissions during the cold phase (bag 1) were reduced by about 46 and 50%, and HC by about 33 and 43%, using nominal 23 and 25% oxygen-enriched air compared to ambient air (21% oxygen by volume), respectively. However, the corresponding oxides of nitrogen (NO{sub x}) emissions were increased by about 56 and 79%, respectively. Time-resolved emissions data indicate that both HC and CO emissions were reduced considerably during the initial 127 s of the cold-phase FTP, without any increase in NO, emissions in the first 25 s. Hydrocarbon speciation results indicate that all major toxic pollutants, including ozone-forming specific reactivity factors, such as maximum incremental reactivity (NUR) and maximum ozone incremental reactivity (MOIR), were reduced considerably with oxygen-enrichment. Based on these results, it seems that using oxygen-enriched intake air during the cold-phase FTP could potentially reduce HC and CO emissions sufficiently to meet future emissions standards. Off-cycle, converter-out, weighted-average emissions results show that both HC and CO emissions were reduced by about 60 to 75% with 23 or 25% oxygen-enrichment, but the accompanying NO{sub x}, emissions were much higher than those with the ambient air.

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

1995-12-31

13

Modeling the effects of late cycle oxygen enrichment on diesel engine combustion and emissions.  

SciTech Connect

A multidimensional simulation of Auxiliary Gas Injection (AGI) for late cycle oxygen enrichment was exercised to assess the merits of AGI for reducing the emissions of soot from heavy duty diesel engines while not adversely affecting the NO{sub x} emissions of the engine. Here, AGI is the controlled enhancement of mixing within the diesel engine combustion chamber by high speed jets of air or another gas. The engine simulated was a Caterpillar 3401 engine. For a particular operating condition of this engine, the simulated soot emissions of the engine were reduced by 80% while not significantly affecting the engine-out NO{sub x} emissions compared to the engine operating without AGI. The effects of AGI duration, timing, and orientation are studied to confirm the window of opportunity for realizing lower engine-out soot while not increasing engine out NO{sub x} through controlled enhancement of in-cylinder mixing. These studies have shown that this window occurs during the late combustion cycle, from 20 to 60 crank angle degrees after top-dead-center. During this time, the combustion chamber temperatures are sufficiently high that soot oxidation increases in response in increased mixing, but the temperature is low enough that NO{sub x} reactions are quenched. The effect of the oxygen composition of the injected air is studied for the range of compositions between 21% and 30% oxygen by volume. This is the range of oxygen enrichment that is practical to produce from an air separation membrane. Simulations showed that this level of oxygen enrichment is insufficient to provide an additional benefit by either increasing the level of soot oxidation or prolonging the window of opportunity for increasing soot oxidation through enhanced mixing.

Mather, D. K.; Foster, D. E.; Poola, R. B.; Longman, D. E.; Chanda, A.; Vachon, T. J.

2002-02-28

14

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

SciTech Connect

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.

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

1996-09-01

15

Scalar dissipation rate at extinction and the effects of oxygen-enriched combustion  

Microsoft Academic Search

The strain rate at extinction was measured in the counterflow flame configuration for methane, propane, and ethane flames as a function of stoichiometric mixture fraction. To complement this, the scalar dissipation rate and flame temperature at extinction were evaluated numerically for methane, ethane, and ethylene flames. The stoichiometric mixture fraction, Zst, was varied by removing nitrogen from the air (oxygen-enriched

R. Chen; R. L. Axelbaum

2005-01-01

16

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

SciTech Connect

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.

Shaddix, Christopher R.; Murphy, Jeffrey J.

2004-09-01

17

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

Microsoft Academic Search

North Carolina A&T State University in Greensboro, North Carolina, has undertaken this project to develop the knowledge and the material to improve the oxygen-enrichment polymer membrane, in order to provide high-grade oxygen-enriched streams for coal combustion and gasification applications. Both experimental and theoretical approaches were used in this project. The membranes evaluated thus far include single-walled carbon nano-tube, nano-fumed silica

Jianzhong Lou; Shamsuddin Ilias

2010-01-01

18

Demonstration of oxygen-enriched air staging at Owens-Brockway glass containers. Quarterly technical progress report for the period August 1, 1996--October 31, 1996  

SciTech Connect

The objective of the program is to demonstrate the use of a previously developed combustion modification technology to reduce NO, emissions from sideport regenerative container glass melters. This technology, known as oxygen-enriched air staging (OEAS), has been demonstrated, and is now being commercialized for endport container glass furnaces. This report focuses on full furnace parametric and long-term testing.

Rue, D.; Abbasi, H.

1997-03-01

19

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

SciTech Connect

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.

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

20

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

PubMed Central

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.

2011-01-01

21

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

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

22

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

SciTech Connect

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

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

1991-11-01

23

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

PubMed

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

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

2011-12-30

24

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

SciTech Connect

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

Jianzhong Lou; Shamsuddin Ilias

2010-12-31

25

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

Microsoft Academic Search

The oxygen-enriched combustion concept, which can minimize off-gas production, has been applied to the incineration of combustible uranium-containing wastes from a nuclear fuel fabrication facility. A simulation for oxygen combustion shows the off-gas production can be reduced by a factor of 6.7 theoretically, compared with conventional air combustion. The laboratory-scale oxygen enriched incineration (OEI) process with a thermal capacity of

J.-G. Kim; H. c C. Yang; G.-I. Park; I.-T. Kim; J.-K. Kim

2002-01-01

26

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

SciTech Connect

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

Rue, D.; Abbasi, H.

1997-03-01

27

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

SciTech Connect

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

Rue, D.; Abbasi, H.

1996-11-01

28

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

SciTech Connect

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.

John M. Veranth; Gautham Krishnamoorthy

2001-04-01

29

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

DOEpatents

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

Balachandran, Uthamalingam (Hinsdale, IL); Bose, Arun C. (Pittsburgh, PA); McIlvried, Howard G. (Pittsburgh, PA)

2001-01-01

30

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

SciTech Connect

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.

John M. Veranth; Gautham Krishnamoorthy

2002-01-01

31

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

SciTech Connect

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.

John M. Veranth; Gautham Krishnamoorthy

2002-02-28

32

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

SciTech Connect

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

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

1991-11-01

33

Interactions among soot, thermal radiation, and NO x emissions in oxygen-enriched turbulent nonpremixed flames: a computational fluid dynamics modeling study  

Microsoft Academic Search

Many combustion applications benefit from the use of oxygen-enriched air or pure oxygen as oxidizer. Oxygen enrichment increases the flame temperature, promotes soot formation and oxidation, and can decrease pollutant emissions compared with hydrocarbon–air systems. Adequate and simultaneous accounting for soot, radiation, and pollutant emissions poses challenges in modeling of oxygen-enriched turbulent flames. Here a comprehensive computational fluid dynamics (CFD)

L. Wang; D. C. Haworth; S. R. Turns; M. F. Modest

2005-01-01

34

Bacterial cellulose production under oxygen-enriched air at different fructose concentrations in a 50-liter, internal-loop airlift reactor  

Microsoft Academic Search

Bacterial cellulose (BC) production by Acetobacter xylinum subsp. sucrofermentans BPR2001 was carried out in a 50-l internal-loop airlift reactor in air at an initial fructose concentration of 40 g\\/l. The BC production rate was 0.059 g\\/l per h. When oxygen-enriched air was supplied instead of air, the BC production rate increased to 0.093 g\\/l per h, and the BC yield

Y. Chao; Y. Sugano; M. Shoda

2001-01-01

35

Novel Membranes and Processes for Oxygen Enrichment  

SciTech Connect

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.

Lin, Haiqing

2011-11-15

36

Efficiency evaluation of oxygen enrichment in energy conversion processes  

SciTech Connect

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.

Bomelburg, H.J.

1983-12-01

37

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

SciTech Connect

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

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

2002-02-26

38

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

SciTech Connect

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 furnace temperature, effectively replacing nitrogen as a diluent. The specially designed burner allows for the safe and effective handling of the four feed streams: air, oxygen, acid gas, and recycle gas. Co-licensed by Goar, Arrington and Associates, Inc. (GAA) and Air Products and Chemicals, Inc., the COPE process presents an economically attractive means of expanding the capacity of an SRU. The first two COPE units are in commercial operation at a major gulf Coast refinery in the USA and have demonstrated an 85% increase in capacity by enriching to the 55% O/sub 2/ level.

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

1986-01-01

39

Effects of oxygen concentration on microbial growth in aerated palm oil mill effluent using oxygen enriched air membrane system  

Microsoft Academic Search

Aeration is one of the most important factors in biological wastewater treatment process. Through aeration, oxygen is supplied to the bacteria to allow their respiration to proceed rapidly and satisfy the biochemical oxygen demand (BOD). This study was carried out to determine the biological growth in aerated palm oil mill effluent (POME) when subjected to aeration using air of different

Ramlah Mohd Tajuddin; Ahmad Fauzi Ismail; Mohd Razman Salim

40

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

Microsoft Academic Search

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

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

1986-01-01

41

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

SciTech Connect

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

Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. (Argonne National Lab., IL (USA)); Assanis, D.N. (Illinois Univ., Urbana, IL (USA)); Schaus, J.E. (Autoresearch Labs., Inc., Chicago, IL (USA))

1990-01-01

42

Taguchi methods applied to oxygen-enriched diesel engine experiments  

SciTech Connect

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

Marr, W.W.; Sekar, R.R.; Cole, R.L.; Marciniak, T.J. [Argonne National Lab., IL (United States); Longman, D.E. [Autoresearch Labs., Inc., Chicago, IL (United States)

1992-12-01

43

Taguchi methods applied to oxygen-enriched diesel engine experiments  

SciTech Connect

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

Marr, W.W.; Sekar, R.R.; Cole, R.L.; Marciniak, T.J. (Argonne National Lab., IL (United States)); Longman, D.E. (Autoresearch Labs., Inc., Chicago, IL (United States))

1992-01-01

44

Mathematical modeling of MSW combustion and SNCR in a full-scale municipal incinerator and effects of grate speed and oxygen-enriched atmospheres on operating conditions  

Microsoft Academic Search

The rising popularity of incineration of municipal solid waste (MSW) calls for detailed mathematical modeling and accurate prediction of pollutant emissions. In this paper, mathematical modeling methods for both solid and gaseous phases were employed to simulate the operation of a 450t\\/d MSW-burning incinerator to obtain detailed information on the flow and combustion characteristics in the furnace and to predict

Zengying Liang; Xiaoqian Ma

2010-01-01

45

Combustion heated air turbine starter system  

Microsoft Academic Search

This paper describes a combustion heated air turbine starter system. It comprises: an air turbine starter operatively associated with a main turbine engine; an auxiliary power unit adapted to deliver air through a bleed duct to the air turbine starter; and means for combusting fuel from a source with air from the auxiliary power unit; the combusting means including an

Shekleton

1991-01-01

46

Fire Extinguishment in Oxygen Enriched Atmospheres.  

National Technical Information Service (NTIS)

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 chemicall...

A. F. Robertson M. W. Rappaport

1973-01-01

47

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

SciTech Connect

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

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

1993-10-01

48

Evaluation of oxygen-enrichment system for alternative fuel vehicles  

SciTech Connect

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.

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

1995-12-01

49

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

SciTech Connect

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

Rue, D.; Abbasi, H.

1997-10-01

50

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...

51

Combustion of Ultrafine Aluminum in Air  

Microsoft Academic Search

The paper reports results of studying the combustion of ultrafine aluminum (surface average diameter of particles is ˜ 0.1 µm) in a sealed bomb at an initial air pressure of 1 atm. The combustion proceeds in two stages, similarly to combustion in air. It is shown that during the two-stage combustion of ultrafine aluminum powder in the bomb, the mass

A. P. Il'in; A. A. Gromov; V. I. Vereshchagin; E. M. Popenko; V. A. Surgin; H. Lehn

2001-01-01

52

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

NASA Astrophysics Data System (ADS)

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.

Koenig, Dieter

1994-01-01

53

Reduction of combustion by-products in WTE plants: O2 enrichment of underfire air in the MARTIN SYNCOM process.  

PubMed

The SYNCOM process involves oxygen enrichment of underfire air, recirculation of flue gas and a combustion control system using infrared thermography of the waste layer on the grate. At the demonstration plant in Coburg, operational reliability and plant availability using SYNCOM could be proven under real disposal conditions with a waste throughput of 7 t/h. Oxygen enrichment of the underfire air promotes the destruction of pollutants due to the high oxygen partial pressures and temperatures. This is then reflected in very low residual amounts of organic combustion by-products in the bottom ash and flue gas from the SYNCOM unit. The flue gas concentrations of organic pollutants are reduced, as compared with conventional operation, by over 35% (for CO, total hydrocarbons and PCDD/F) at the boiler outlet. As the flue gas flow is reduced by oxygen enrichment and flue gas recirculation, the resulting reduction in terms of kg of pollutant per Mg of waste is even higher. In the bottom ash, the level of organic residues is reduced, by 45% in the case of loss on ignition and by 55% in the case of TOC and dioxins (I-TE of PCDD/F). This is due to the higher oxygen partial pressures and the fuel bed temperature which is increased by 135 to 1200 degrees C. Other important features of the process include more intense sintering and thus improved immobilization of the bottom ash, as well as reduced flue gas and fly ash flows. PMID:11219678

Gohlke, O; Busch, M

54

Gas turbine combustion chamber with air scoops  

Microsoft Academic Search

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

S. E. Mumford; J. P. Smed

1989-01-01

55

Combustion-generated indoor air pollution  

Microsoft Academic Search

The indoor air quality of residential buildings was characterized to determine the types, rates of emissions, and fates of gaseous and particulate air pollutants from typical indoor combustion appliances. Measurements were conducted in occupied residential buildings and during controlled laboratory experiments with combustion appliances. The SO, NO, NO, O, CO, and CO concentrations and aerosol size distribution were determined on

C. D. Hollowell; G. W. Traynor

1978-01-01

56

Emisiones al Aire de la Combustion de Llantas Usadas (Air Emissions from Scrap Tire Combustion).  

National Technical Information Service (NTIS)

The report discusss 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 atmospher...

J. I. Reisman

1997-01-01

57

Impinging air jet combustion apparatus  

Microsoft Academic Search

A combustion liner for a gas turbine combustion apparatus or the like has a head wall and a side wall extending downstream to an outlet for combustion products. A reaction zone is contained within the upstream end of the side wall and a dilution zone downstream. A barrier ring extends inwardly from the side wall to provide a constricted path

J. R. Arvin; A. J. Verdouw

1976-01-01

58

Theoretical analysis of aqueous residues incineration with oxygen enriched flames  

SciTech Connect

The use of oxygen to enrich the oxidizer can be an attractive alternate to increase incineration rates of a combustion chamber originally designed to operate with air. For a certain fuel flow rate, if some incineration parameters are held constant (as combustion chamber temperature, turbulence level, and residence time), an increase of incineration rates becomes possible with injection of oxygen. This work presents a theoretical evaluation of combustion air enrichment in a combustion chamber designed to incinerate aqueous residues using methane as fuel and air as oxidizer. Detailed chemistry was employed to predict pollutants formation. The overall process was investigated using the PSR routine from the CHEMKIN library.

Lacava, P.T.; Pimenta, A.P.; Veras, C.A.G.; Carvalho, J.A. Jr.

1999-10-01

59

Combustion air can become a problem  

SciTech Connect

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

Not Available

1982-01-01

60

The oxygen enrichment of the galaxy  

SciTech Connect

Oxygen-to-hydrogen ratios are calculated for the 97 planetary nebulae for which there are sufficient data and for which the correction for unobserved ionization states is not too large. As a part of this study, emission-line fluxes are presented for 19 planetaries. The ratios are strongly correlated with population type. Almost all planetaries with absolute LSR radial velocity greater than about 85 km s/sup -1/ and distance from the galactic plane greater 1 kpc have low O/H; high values of O/H are confined to the galactic disk. The radial gradient within the disk is not easily discerned from the planetaries. An apparent gradient is seen because the planetaries with distances from the galactic center greater than about 11 kpc are dominantly halo objects with high velocity or large distance from the plane. The planetaries are divided into relative age groups which depend upon the nubular velocities, distances from the galactic plane, excitation levels, and He/H ratios. The mean O/H for each group increases with decreasing age. The available evidence shows that this effect is not due to nuclear processing in individual stars and is consequently an effect of galactic evolution. Galactic O/H has increased by a factor of between 5 and 10 from the time of the formation of the early halo to the present, consistent with earlier studies. The relative oxygen enrichment rate of the Galaxy is characterized by a large early increase from the old to the intermediate halo, followed by a smaller but steady relative enrichment rate among the identified age groups.

Kaler, J.B.

1980-07-01

61

Combination of supercritical wet combustion and compressed air energy storage  

Microsoft Academic Search

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

1986-01-01

62

The VSA Process for Oxygen Enrichment: Process Description and Dynamic Modeling Using Neural Networks  

Microsoft Academic Search

Air separation for oxygen enrichment via the pressure\\/vacuum swing adsorption (PSA\\/VSA) process is an important unit operation in many large industrial processes. However, complexities associated with it being a bulk separation process operating in a cyclic, non-equilibrium, unsteady state manner presents significant difficulties in understanding the physics involved. Also, previous attempts in modeling the system numerically have resulted in complications

Chris C. K. Beh; Paul A. Webley; Kate A. Smith

2003-01-01

63

EFFECTS OF HYBRID REBURNING\\/SNCR STRATEGY ON NOX\\/CO REDUCTION AND THERMAL CHARACTERISTICS IN OXYGEN-ENRICHED LPG FLAME  

Microsoft Academic Search

From the view of the environmental protection against the usage of fossil fuels, a great amount of effort has been exerted to find an effective method that is not only for pollutant reduction, but also for higher thermal efficiency. In order to enhance combustion efficiency, oxygen-enriched combustion is used by increasing the oxygen ratio in the oxidizer. However, since the

CHANG YEOP LEE; SEUNG WOOK BAEK

2007-01-01

64

Air cleaning means for internal combustion engine  

SciTech Connect

Air cleaning means suitable for use with an internal combustion engine are disclosed that includes a fuel vapor adsorbing filter element and a sucked air cleaning filter element arranged independently of and separately from each other. The fuel vapor adsorbing filter element includes a filter material layer containing fibers of active carbon for adsorbing fuel vapors thereon, and a metallic reinforcing member, while a sucked air cleaning filter element includes a filter material layer of the usual type for cleaning the air drawn by suction into a combustion chamber of the internal combustion engine. The fuel vapor adsorbing filter element may further include a plurality of reinforcing layers of nonwoven fabric each located on one of opposite sides of the filter material layer. The filter material layer and the reinforcing layers of nonwoven fabric may be formed with a plurality of apertures extending therethrough, and an additional layer of nonwoven fabric may be mounted between the metallic reinforcing member and one of the plurality of reinforcing members of nonwoven fabric which is located inside the filter material layer.

Nakamura, Y.; Yamakawa, Y.

1981-07-21

65

Role of palladium at superfine aluminum powder combustion in air  

Microsoft Academic Search

Palladium influence to combustion steps, temperature regime and final products composition by superfine aluminum powder combustion in air was studied. It is shown, that palladium, possibly, doesn't participate in nitrogen fixation mechanism; but microstructure characteristics of combustion products shows that they forms by palladium presence: significant part of combustion products stabilize as needle polycrystals.

A. P. Ilyin; A. A. Gromov; E. M. Popenko

1999-01-01

66

Air Augmented Rocket Fixed Fuel Flow Combustion Characterization Program.  

National Technical Information Service (NTIS)

This program demonstrated that reliable, consistent combustion efficiency data could be obtained independently at different facilities. The detailed combustion efficiency performance of two Boron loaded fuel rich propellants was mapped over an air-to-fuel...

J. L. Fields

1973-01-01

67

Analysis of Scramjet Flight Trajectories with Oxygen Enrichment  

Microsoft Academic Search

Scramjets are proposed as a second stage for a mult i-stage access-to-space system. At present the upper limit of scramjet operation is expected to be Mach 12-14. Use of oxy gen enrichment is a possible method for increasing the speed and altitude of scramjet operation. This paper involve s mission analysis of scramjets using oxygen enrichment. It f ollows on

S. A. Razzaqi; M. K. Smart; N. Weidner

68

Analysis of Combustion Air Openings to the Outdoors: Preliminary Results. Topical Report, October 1992-June 1994.  

National Technical Information Service (NTIS)

This report examines the technical and historical bases for existing combustion air requirements in the U.S. in cases where combustion air is obtained entirely from the outdoors and recommends sizing guidelines for combustion air openings to the outdoors ...

A. L. Rutz D. B. Philips D. W. DeWerth L. Ni

1994-01-01

69

Ignition combustion pre-chamber for internal combustion engines with constant stoichiometric air-fuel mixture at ignition  

Microsoft Academic Search

This patent describes an internal combustion engine including at least one combustion chamber and a pre-chamber in fluid communication with the combustion chamber, a method of providing combustion within the combustion chamber. It comprises charging the combustion chamber with a first mixture of air and fuel having a lean ratio of air-to-fuel; charging the pre-chamber with a further mixture of

1992-01-01

70

CFD Simulation of High Temperature Air Combustion of Coal Gas at Different Air Straddle Angle  

Microsoft Academic Search

Numerical simulation was carried out on the High Temperature Air Combustion of coal gas in an industrial furnace with a multi-jet burner. A Beta-function PDF (Probability Density Function) combustion model was selected to simulate the gas combustion combined with the standard k-? turbulent model. The radiation was simulated by a Discrete Ordinates method. Thermal NOx model was used to calculate

Yaxin Su; Bingtao Zhao

2010-01-01

71

Comparative study of lean and rich filtration combustion of methane\\/air, ethane\\/air, and propane\\/air mixtures  

Microsoft Academic Search

This work comparatively analyzes lean, rich and ultrarich combustion of methane (CH4)\\/air, ethane (C2H6)\\/air and propane (C3H8)\\/air mixtures inside inert porous media. Temperature, velocity, and chemical products of the combustion waves were studied experimentally in the range of equivalence ratios (?) from 0.2 to 2.5, at a single filtration velocity of 12 cm\\/s. Low-velocity regime (LVR) of filtration gas combustion

MARIO TOLEDO; VALERI BUBNOVICH; ALEXEI SAVELIEV; LAWRENCE KENNEDY

72

Air to fuel ratio control system for internal combustion engine  

Microsoft Academic Search

An air to fuel ratio control system for an internal combustion engine having a fixed venturi type carburetor is disclosed. The air to fuel ratio control system comprises a device for extracting an atmospheric pressure within a venturi or a pressure corresponding to a relieved venturi vacuum, a device for extracting a static fuel pressure downstream of a main jet

Y. Nishimura; Y. Oyama

1980-01-01

73

Application of Oxygen-Enriched Aeration in the Conversion of Glycerol to Dihydroxyacetone by Gluconobacter melanogenus IFO 3293  

PubMed Central

Gluconobacter melanogenus 3293 converts glycerol to dihydroxyacetone(DHA) during exponential growth on a yeast extract-phosphate medium at pH 7. The efficiency of this conversion in 25-liter batch fermentations has been found to increase over threefold, when oxygen tension is controlled by increasing the partial pressure of oxygen in the aeration. Conversion of glycerol to DHA does not occur under oxygen-limited fermentation conditions. When the dissolved oxygen tension was maintained at 0.05 atmospheres (using oxygen-enriched air), quantitative conversion of up to 100 g of glycerol/liter to DHA was obtained in 33 h. The amount of glycerol converted can be increased without increasing impeller speed or aeration rate. This increase is not the result of increased production of cell mass. The specific conversion of glycerol to DHA increased from 12.2 g of DHA/g of cell mass at the point of maximum conversion to 35.8 with oxygen enrichment. This increased specific production occurred even though the specific growth rate during the period of oxygen enrichment decreased from 0.23 to 0.06/h. Images

Flickinger, M. C.; Perlman, D.

1977-01-01

74

Combustion response of an aluminum droplet burning in air  

Microsoft Academic Search

The combustion in air of a 100?m-diameter aluminum droplet is studied by direct Navier–Stokes simulations. The model only considers the gas phase and includes a reduced Al\\/O2 kinetic scheme with 8 species and 10 reactions. The model is validated against experimental burn time data and appears to be fairly correct despite its simplicity. The unsteady combustion is then investigated by

Stany Gallier; Fabien Sibe; Olivier Orlandi

2011-01-01

75

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

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

L. H. Yang

2008-01-01

76

Inhibiting the combustion of air-methane mixtures  

NASA Astrophysics Data System (ADS)

It is found that additives containing i-C4H8, CO2, CF3H, and CF4 effectively inhibit the ignition and combustion of air-methane mixtures of any composition at atmospheric pressure, evidence of the branched-chain character of methane combustion. The reason for the great distinction between the efficiency of inhibiting methane and hydrogen combustion by trifluoromethane is found. The synergism in the joint effect of the abovementioned additives is revealed and taken advantage of. It is shown that the effect is inherent to the branched-chain mechanism.

Azatyan, V. V.; Saikova, G. P.

2013-10-01

77

Filtration combustion of hydrogen-air, propane-air, and methane-air mixtures in inert porous media  

Microsoft Academic Search

The filtration combustion characteristics of hydrogen-air, propane-air, and methane-air mixtures in inert porous media have\\u000a been studied experimentally. It is shown that the dependences of the combustion wave velocity on the fuel-air equivalence\\u000a ratio are V-shaped. For hydrogen-air mixtures, the velocity minimum is shifted to the rich region, and for propane-air and\\u000a methane-air mixtures, it is shifted to the lean

N. A. Kakutkina; A. A. Korzhavin; M. Mbarawa

2006-01-01

78

External combustion slidable vane motor with air cushions  

SciTech Connect

This patent describes an external combustion sliding-vane engine comprising the following: a motor member including means for compressing ambient air and means for expanding the combusted gas resulting from the combustion of fuel in the compressed air; a combustion member for receiving compressed air from the motor member, mixing the fuel with compressed air, igniting the mixture and burning the fuel, and delivering the combusted gas to the motor member; a shaft connecting the compression and expanding means for delivering power by means of an external drive shaft; the motor member further including cylindrical center bodies, hollow external structures surrounding and enclosing corresponding ones of the center bodies, flanges supporting the center bodies and hollow external structures for relative rotation between the shaft axis. Each center body and corresponding hollow external structure is positioned between a corresponding pair of adjacent flanges. The external hollow structures and the center bodies have continuously curved surfaces positioned to face each other, and radially extending vane means extending between each pair of adjacent flanges at circumferentially spaced locations. Each vane means extends from an outer facing surface of a corresponding center body to an inner facing surface of a corresponding external hollow structure to define circumferentially spaced sealed spaces between the flanges and the circumferential facing surfaces.

David, C.V.

1987-06-16

79

Closed loop air cooling system for combustion turbines  

DOEpatents

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

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

1998-07-21

80

Closed loop air cooling system for combustion turbines  

DOEpatents

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.

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

1998-01-01

81

Combustion performance evaluation of air staging of palm oil blends.  

PubMed

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

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

2012-02-10

82

The effect of air preheating on the combustion of solid fuels on a grate  

Microsoft Academic Search

Combustion of solid fuels on a grate is widely used. Mostly, the combustion behaviour is explained by the classical theory of Rogers. However, that theory cannot explain the combustion process when primary air preheating is applied. Solid fuel grate combustion is studied by experiments in a pot furnace. Experiments with and without primary air heating are described. These are compared

L. B. M van Kessel; A. R. J Arendsen; P. D. M de Boer-Meulman; G Brem

2004-01-01

83

Oxygen Enrichment for Open Cycle Magnetohydrodynamic Power Systems.  

National Technical Information Service (NTIS)

Efficient coal fired, open cycle MHD power generation systems require a combustion flame temperature of approximately 4600 F to provide adequate electrical conductivity in the MHD gas. To achieve this high flame temperature, either highly preheated combus...

1979-01-01

84

Numerical calculations of hydrogen-air combustion. [PWR; BWR  

SciTech Connect

One serious concern during the accident at Three Mile Island resulted from the generation of a large amount of hydrogen gas and its migration to the containment building. The fear was that combustion of this hydrogen could produce pressures that would breach containment. The Center for Nonlinear Studies at Los Alamos is sponsoring an effort to assess the Laboratory's current numerical capabilities to model the combustion of hydrogen-air mixtures in realistic geometries. Such detailed numerical models allow us to understand very complex experimental behavior.

O'Rourke, P.J.

1983-08-01

85

Method of oxygen-enriched two-stage underground coal gasification  

Microsoft Academic Search

Two-stage underground coal gasification was studied to improve the caloric value of the syngas and to extend gas production times. A model test using the oxygen-enriched two-stage coal gasification method was carried out. The composition of the gas produced, the time ratio of the two stages, and the role of the temperature field were analysed. The results show that oxygen-enriched

Liu Hongtao; Chen Feng; Pan Xia; Yao Kai; Liu Shuqin

2011-01-01

86

The effect of inlet air vitiation on combustion efficiency  

SciTech Connect

Experimental results of the effect of inlet air vitiation produced by a vitiating preheater on combustion efficiency of a turbojet combustor and a model ramjet combustor are presented in this paper. An empirical correlation and a calculation method based on stirred reactor theory are derived to correct the vitiation effect. Results obtained by means of these two methods are in good agreement with test data.

Zuomin, F.; Yijun, J.

1985-01-01

87

Kinetic mechanism of propane ignition and combustion in air  

Microsoft Academic Search

A detailed kinetic model of propane ignition and combustion in air is developed. The model includes 599 reactions with 92\\u000a species and involves both the high-temperature and low-temperature mechanisms of oxidation. The model is tested against experimental\\u000a data on the ignition delay time, on propane conversion during low-temperature oxidation, on changes in species concentrations\\u000a during propane pyrolysis, and on laminar

N. S. Titova; P. S. Kuleshov; A. M. Starik

2011-01-01

88

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

Microsoft Academic Search

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

Junmin Wang

2008-01-01

89

PROPERTIES OF PULVERIZED COAL COMBUSTION IN HIGH TEMPERATURE AIR\\/STEAM MIXTURE  

Microsoft Academic Search

High temperature air combustion (HiTAC) is a promised combustion technology. It has been proved that when the oxygen concentration in the preheated air is diluted, the NOx emission for fossil fuels will be significantly reduced. When this idea is applied to pulverized coal combustion, the same advantages can be expected. Water has high specific heat, and can react with coal

ZHANG QINGLIN; SWIDERSKI ARTUR; YANG WEIHONG; WLODZIMIERZ BLASIAK

90

Method and apparatus for igniting a combustible mixture, especially gasoline-air in the combustion chamber of an internal combustion engine  

SciTech Connect

In an internal combustion engine, an apparatus is described for igniting a combustible fuel-air mixture within the combustion space of the cylinder of the combustion engine. The engine comprises: a sparkplug having spark electrodes located in the combustion space; ignition spark generating apparatus coupled to the sparkplug; and means to enhance energy output from the sparkplug for ignition during the breakdown phase of sparking of the sparkplug comprising means for sensing air quantity being supplied to the engine and for providing an air quantity signal; means for sensing fuel quantity being supplied to the engine and for providing a fuel quantity signal; and a control unit controlling the number of breakdowns of spark flash-overs across electrodes of the sparkplug as a function of the output representative of the ratio of fuel to air.

Herden, W.

1987-03-31

91

The effects of inhomogeneity in DME-Air mixture in combustion chamber on homogeneous charge compression ignition combustion  

Microsoft Academic Search

In the HCCI Engine, the inhomogeneity exists in fuel distribution and temperature in the pre-mixture microscopically, and has the possibility of affecting the ignition and combustion process. In this study, the effect of the inhomogeneity in DME\\/n-Butane-Air mixture in the combustion chamber on the HCCl combustion was investigated by chemiluminescence method in order to understand the spatial distribution of the

Ock Taeck Lim; Satoshi KETADANI; Kengo KUMANO; Norimasa IIDA

2007-01-01

92

Study of aluminum nitride formation by superfine aluminum powder combustion in air  

Microsoft Academic Search

An experimental study on the combustion of superfine aluminum powders (average particle diameter as?0.1 ?m) in air is reported. Formation of aluminum nitride during combustion of aluminum in air is focused in this study. Superfine aluminum powders were produced by wire electrical explosion (WEE) method. Such superfine aluminum powder is stable in air but, if ignited, it can burn in

Alexander Gromov; Vladimir Vereshchagin

2004-01-01

93

In-Depth Experimental Study of Solid-Waste Destruction by High Temperature Air Combustion  

Microsoft Academic Search

The objective of this article is to investigate the application of high temperature air combustion in thermal destruction of solid waste. The secondary air was preheated at different temperatures and burned with low calorific value and high content of diluted inert gas released from solid waste. It was discovered that the combustion with the higher preheated secondary air temperature had

P. Suvarnakuta; S. Patumsawad; S. Kerdsuwan

2009-01-01

94

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...

95

Special features of combustion of propane-air and hydrogen-air mixtures in a narrow tube  

Microsoft Academic Search

The special features of combustion-wave propagation in a narrow tube have been studied experimentally in low-velocity regimes\\u000a for propane-air and hydrogen-air mixtures. For propane mixtures, the increase in the curvature of the flame surface correlates\\u000a with the displacement of the maximum into the region of enriched mixtures in the dependence of the combustion velocity on\\u000a the mixture composition. Combustion of

V. V. Zhamashchikov

1997-01-01

96

Atmospheric pressure fluctuations and oxygen enrichment in waste tanks  

SciTech Connect

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

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

1993-07-01

97

Stabilization of the Flame of a Powdered Metal Combustible in a Turbulent Air Flow  

Microsoft Academic Search

The process of stabilization of the flame of a powdered metal combustible in a combustion chamber with sudden expansion is studied. Experimental data on the influence of the main factors on the limits of stable combustion in a turbulent flow of an aluminum–air mixture are obtained.

A. G. Egorov; E. D. Kal'nei; A. P. Shaikin

2001-01-01

98

Air supply and venting to improve performance of residential combustion appliances  

Microsoft Academic Search

With homes being made tighter, combustion appliances are having an increasingly difficult time receiving adequate air to operate safely and properly. Spillage of incomplete combustion products or even chimney flow reversals (backdrafting) can result in significant amounts of carbon monoxide and other toxic combustion products being exhausted into the house. Some of these pollutants may cause immediate acute, even life

A. C. S. Hayden; F. Preto

1988-01-01

99

Effect of combustion chamber shape on air flow field in a D. I. diesel engine  

Microsoft Academic Search

The behaviour of two combustion chambers, a toroidal and a turbulent one, has been compared. The engine performance in terms of imep and exhaust emissions were measured. Laser Doppler Anemometry technique was used to characterize the fluids dynamic aspect of combustion system. The axial asymmetry introduced in combustion chamber shape causes strong differences in the air flow field at the

C. Bertoli; F. E. Corcione; G. Police; G. Valentino

1987-01-01

100

Oxygen Enrichment of Ceramic Roller Hearth Atmosphere and Burners. Final Technical Report December 1983-January 1985.  

National Technical Information Service (NTIS)

The goal of the project was to determine the economic feasibility of oxygen enrichment in a roller hearth to accelerate carbon burnout in red body ceramic tile. An oxygen storage and distribution system was installed on a full-sized roller hearth kiln; fu...

M. A. Rogalla

1985-01-01

101

Ilmenite Smelted by Oxygen-Enriched Top-Blown Smelting Reduction  

Microsoft Academic Search

Total ilmenite from Yunnan, China, difficult to smelt in blast furnace, was smelted by oxygen-enriched top-blown smelting reduction ironmaking technology. Much more details on smelting were discussed. Specifically, the influence of reduction temperature, slag basicity and molar ratio of carbon to oxygen on the reduction quality level including iron recovery and titanium and sulfur contents in the pig iron produced

Hui-bin LI; Hua WANG; Yi-long QI; Jian-hang HU; You-ling LI

2011-01-01

102

Effect of air-staging on anthracite combustion and NOx formation  

SciTech Connect

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.

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

2009-01-15

103

On the Effect of Air Temperature on Mild Flameless Combustion Regime of High Temperature Furnace  

Microsoft Academic Search

This paper presents an experimental study of the ef fect of air preheating temperature on the main feat ures of mild flameless combustion obtained in a laboratory-scale furnace. Mild flameless combustion regime is conse rved whatever the air temperature varying from 838 K to ambient value. No visible flame is observed. Main a erodynamic features of the flow at the

C. Rottier; C. Lacour; G. Godard; B. Taupin; L. Porcheron; R. Hauguel; S. Carpentier; A. M. Boukhalfa; D. Honoré

104

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

Microsoft Academic Search

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

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

2007-01-01

105

Comparisons of pulverized coal combustion in air and in mixtures of O 2\\/CO 2  

Microsoft Academic Search

Pulverized coal combustion in air and the mixtures of O2\\/CO2 has been experimentally investigated in a 20kW down-fired combustor (190mm id×3m). Detailed comparisons of gas temperature profiles, gas composition profiles, char burnouts, conversions of coal–N to NOx and coal–S to SO2 and CO emissions have been made between coal combustion in air and coal combustion in various O2\\/CO2 mixtures. The

Hao Liu; Ramlan Zailani; Bernard M. Gibbs

2005-01-01

106

Site-specific air inlet systems for combustion turbines  

SciTech Connect

Each combustion turbine installation has peculiar to it site-related characteristics that, if considered carefully, will define the type of inlet system that best fits the turbine`s operational requirements. Turbine performance and component service life greatly depend on the ability of an air inlet system to reduce or eliminate contaminants entering the system. If these contaminants are not effectively removed, then fouling, erosion, and low- and high-temperature corrosion will occur. High-efficiency air filtration and low resistance is important from the initial start-up to the recommended filter change out. Users and operators are fast coming to the conclusion that a single component/filter house design cannot be used successfully for all geographic regions and for all gas turbine duties and specific site conditions. Additionally, any well-designed filter house should provide an economical solution for initial cost, as well as continued operating cost, and through the use of modular design accommodate the addition of evaporative coolers and future upgrades in air filter components. New high and ultra-high filter efficiencies also have lower initial resistance and, when combined with a pleated panel prefilter, have the highest system dust holding capacity available today.

Goulding, C.H.; Gidley, D.S. [Farr Co., El Segundo, CA (United States)

1995-10-01

107

Premixing gas and air to reduce NO\\/sub x\\/ emissions with existing proven gas turbine combustion chambers  

Microsoft Academic Search

In the case of the burners employed in KWU gas turbine combustion chambers, the entire primary air is supplied through the swirlers associated with the burners. It is thus relatively easy to add natural gas to this air uniformly before it enters the combustion zone. This results in a particularly low NO\\/sub x\\/ combustion process provided that the air to

B. Becker; P. Berenbrink; H. Brandner

1986-01-01

108

Properties of methanol-air mixtures and their products of combustion  

Microsoft Academic Search

This paper describes the calculation procedures used to generate a set of thermodynamic property tables for methanol-air mixtures and their products of combustion. In addition to liquid methanol and methanol vapour\\/air properties, two phase air\\/liquid methanol\\/methanol vapour properties are also evaluated. Both undissociated products of combustion and dissociated products in chemical equilibrium are determined. Abridged samples of the resulting tables

M. F. Bardon; W. C. Moffatt; J. A. Mordy

1980-01-01

109

Properties of methanol-air mixtures and their products of combustion  

SciTech Connect

This paper describes the calculation procedures used to generate a set of thermodynamic property tables for methanol-air mixtures and their products of combustion. In addition to liquid methanol and methanol vapour/air properties, two phase air/liquid methanol/methanol vapour properties are also evaluated. Both undissociated products of combustion and dissociated products in chemical equilibrium are determined. Abridged samples of the resulting tables are provided and examples of typical calculations are given to illustrate the use of the tables for internal combustion engine and gas turbine calculations.

Bardon, M.F.; Moffatt, W.C.; Mordy, J.A.

1980-12-01

110

APTI (Air Pollution Training Institute) Course 427: combustion evaluation, student manual  

SciTech Connect

This Student Manual is used in conjunction with Course No. 427, 'Combustion Evaluation' as applied to air pollution control situations. This manual was prepared by the EPA Air Pollution Training Institute (APTI) to supplement the course lecture materials and to present detailed reference information on the following topics: combustion fundamentals, fuel properties, combustion system design, pollutant emission evaluations, combustion control, gas, oil, and coal burning, solid waste and wood burning, incineration of wastes, sewage sludge incineration, waste gas flares, hazardous waste combustion, NOx control, and improved combustion systems. Note: There is also an Instructor's Guide to be used in conducting the training course - (EPA-450/2-80-065) and a Student Workbook to be used for homework and in-class problem solving - (EPA-450/2-80-64).

Beard, J.T.; Iachetta, F.A.; Lilleleht, L.U.

1980-02-01

111

APTI (Air Pollution Training Institute) course 427: combustion evaluation, instructor's guide  

SciTech Connect

This Instructor's Guide is used in conjunction with Course No. 427, 'Combustion Evaluation' as applied to air pollution control situations. The teaching guide was prepared by the EPA Air Pollution Training Institute (APTI) to assist instructors in presenting course No. 427. The guide contains sections on the following topics: combustion fundamentals, fuel properties, combustion system design, pollutant emission calculations, combustion control, gas, oil, and burning, solid waste and wood burning, incineration of wastes, sewage sludge incineration, flame and catalytic incineration, waste gas flares, hazardous waste combustion, NOx control, improved combustion systems. Note: There is also a Student Workbook to be used for homework and in-class problem solving (EPA-450/2-80-064) and a Student Manual for reference and additional subject material (EPA-450/2-80-063).

Beard, J.T.; Iachetta, F.A.; Lilleleht, L.U.

1980-02-01

112

An experimental study on high temperature and low oxygen air combustion  

NASA Astrophysics Data System (ADS)

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

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

2000-06-01

113

Thermal and emission characteristics of high temperature air combustion: A technical review  

Microsoft Academic Search

High temperature air combustion (HiTAC) is proved to be a promising combustion technology for industrial applications. HiTAC is more advantageous than conventional combustion technologies for several reasons: decreased energy consumption, enhanced heat transfer, the uniformity of temperature distribution, decreased CO2 emission, low NOX and CO emissions. This article provides a comprehensive picture of the recent research and developments in HiTAC.

Zhenjun Cao; Jin Chaohua

2010-01-01

114

Air-to-fuel ratio adjusting system for an internal combustion engine  

Microsoft Academic Search

A carburetor for applying air-fuel mixture to an internal combustion engine includes a main passage for applying air-fuel mixture and principally controlling the amount thereof. The air-to-fuel ratio of the air-fuel mixture to be supplied to the engine is detected by an air-to-fuel ratio detector mounted in an exhaust pipe of the engine, and when the detected ratio is lower

T. Hattori; S. Takada; F. Sugi; T. Nakase

1977-01-01

115

Propane–Air Mixture Combustion Assisted by MW Discharge in a Speedy Airflow  

Microsoft Academic Search

In this paper, results are presented from an experimental investigation of propane-air combustion in a stationary microwave (MW) discharge at different conditions. In these experiments, a deeply undercritical discharge is initiated in the base of an electromagnetic vibrator, which is immersed in cold supersonic airflow. Two schemes for mixing propane with air are considered. In the first scheme, a propane-air

Igor I. Esakov; Lev P. Grachev; Kirill V. Khodataev; Viacheslav A. Vinogradov; David M. Van Wie

2006-01-01

116

Nitride Formation during Combustion of Ultrafine Aluminum Powders in Air. I. Effect of Additives  

Microsoft Academic Search

This paper summarizes the results from studies of the effect of 17 additives on the process and products of ultrafine aluminum combustion in air. It is shown that the additives influence the temperature and duration of the combustion process and the structure of the end products, including the yield of aluminum nitride. The major factor determining the yield of aluminum

A. A. Gromov; E. M. Popenko; A. V. Sergienko; A. P. Il’in; V. I. Vereshchagin

2005-01-01

117

Air supply and venting to improve performance of residential combustion appliances  

SciTech Connect

With homes being made tighter, combustion appliances are having an increasingly difficult time receiving adequate air to operate safely and properly. Spillage of incomplete combustion products or even chimney flow reversals (backdrafting) can result in significant amounts of carbon monoxide and other toxic combustion products being exhausted into the house. Some of these pollutants may cause immediate acute, even life threatening problems; others may cause longer term chronic health problems. Concern about the quality of indoor air has increased commensurately, with international technical organizations (eg. ASHRAE, APCA) identifying it as a major problem. The causes of spillage and backdrafting cannot be attributed to a single component of the combustion system. Conventional appliances, lacking in forced draft generators, must rely on natural draft created by the temperature difference between the flue gas and the outdoor air. Unfortunately, large quantities of dilution air and/or poorly designed systems result in large quantities of lukewarm stack gas which translate into poor draft. In other cases, the chimney itself may be at fault either through being oversized, physical deterioration or poor location. Again the result is poor draft and possible combustion product spillage or backdrafting. The elimination of these problems must therefore address not only the combustion appliances but also the chimney and associated venting system. This book discusses gas-or oil-fired combustion systems, which eliminate the dilution device and forcibly exhaust the combustion products.

Hayden, A.C.S.; Preto, F. (Canadian Combustion Research Lab., Ottawa, Ontario (CA))

1988-01-01

118

Controlling Combustion-Source Emissions at Air Force Sites with a New Filter Concept. Phase 1.  

National Technical Information Service (NTIS)

The U.S. Air Force employs many combustion sources at its facilities, including boilers, diesel engines, turbines, incinerators, and motor vehicles, that produce exhaust gases containing undesirable components. Components of concern include nitrogen oxide...

S. G. Nelson D. A. Van Stone B. W. Nelson K. A. Peterson

1994-01-01

119

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

National Technical Information Service (NTIS)

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. Th...

A. K. Gupta M. Ghaderi

2004-01-01

120

Performance of High Temperature Air Combustion Boiler with Low NOx Emission  

Microsoft Academic Search

Thermal performance in the experiments and three-dimensional numerical simulations for a high temperature air combustion boiler where fuel can be efficiently combusted by high temperature preheated air (800°C-1000°C) is examined. The boiler can burn not only natural gas but also low calorific gas (e. g. full gasification gas obtained from coal or wastes). In the boiler, four regenerative burners are

Hiromichi Kobayashi; Yoshihito Ito; Naoki Tsuruta; Kunio Yoshikawa

2002-01-01

121

Experimental investigations on adsorption air-conditioner used in internal-combustion locomotive driver-cabin  

Microsoft Academic Search

An internal-combustion locomotive driver-cabin adsorption air-conditioner is a new type of space cooling system, which employs zeolite-water as working pairs and is driven by the waste heat from the exhaust gas of internal-combustion engines. Experiment methodology of this air-conditioner is presented and the results and their impact factors are discussed. Refrigeration output performances under adiabatic and cooling conditions are analyzed

S. Jiangzhou; R. Z. Wang; Y. Z. Lu; Y. X. Xu; J. Y. Wu

2002-01-01

122

Device for electronically controlling the intake air temperature of an internal combustion engine  

SciTech Connect

A device for electronically controlling the intake air temperature of an internal combustion engine, featuring a temperature sensor in the clean air space of the filter, the signal from the sensor controlling an electromagnetically driven oscillator pump whose vacuum output adjusts the flapper of an air flow proportioning valve by means of a pneumatic actuator, until the correct ratio of cold and preheated raw air is admitted into the intake system for the establishment of an optimal combustion air temperature. An automatic lowering of this temperature under full-load operation is achieved by utilizing the negative pressure in the air intake manifold as a control means to shift the oscillating armature of the oscillator pump away from its maximum output position. In an air intake system for fuel injected engines, a similar result is achieved by means of an air flow sensor whose output signal is superimposed on the control signal from the temperature sensor.

Bach, W.; Blumhardt, R.; Fusser, R.; Ruckert, K.

1981-04-07

123

Electric air preheater for an internal combustion engine  

SciTech Connect

A preheater adapted to be connected to an internal combustion engine is described comprising a hollow cylinder, a cover element at each end of the hollow cylinder. The hollow cylinder and cover elements collectively defining an elongate closed heating chamber, an elongate electric heating element in the form of a cylindrical rod supported by the cover element at one end of the hollow cylinder in coaxial relation with the longitudinal axis of the hollow cylinder such as to define with the wall of the cylinder an annular space surrounding the heating element, the cover element at the one end containing an opening defining an air inlet passage into the annular space within the heating chamber, a valve body defining a flow passage closed at one end and open at the other, a coupling element connecting the valve body to the cover element at the other end of the hollow cylinder and embodying a flow passage in communication at one end with the annular space within the heating chamber and at the other end with the flow passage in the valve body intermediate the ends of the valve body flow passage and a spring-biased check valve element located in the flow passagage in the valve bogy adjacent to the open end. The spring-biased valve element is biased in a direction to permit flow from the heating chamber through the flow passage in the valve body in the direction of the open end and to prevent flow in a direction from the open end toward the closed end.

Chen, L.J.; Hsiang, T.P.

1986-08-12

124

Intake air heater for internal combustion engine with perforated plate heater element partially traversing air passage  

SciTech Connect

An air heater is described for heating intake air for an internal combustion engine, comprising a frame means for defining an opening for passing air therethrough, and at least one piece of heater element in the shape of a perforated plate supported by the frame means so as to traverse a predetermined part of the opening area of the opening, a substantial part of the opening area being left free as untraversed by the heater element wherein the frame means is an annular frame means which defines the opening by inner peripheral edges thereof, and which has an annular groove formed along inner peripheral portions thereof so as to extend from the inner peripheral edges into the frame means toward outer peripheral portions thereof. The heater element is supported by the frame means with a first part thereof being received in the annular groove, while a second part thereof is exposed to the opening area of the opening and wherein the annular frame means is an assembly of two annular frame members joined together along a border extending through and including bottom portions of the annular groove.

Tanaka, T.; Niwa, H.; Mukai, H.; Hori, M.; Miwa, N.; Nara, A.; Nomura, E.; Hasegawa, K.; Noguchi, H.

1987-08-11

125

Use of Fluidic Oscillator to Measure Fuel-Air Ratios of Combustion Gases.  

National Technical Information Service (NTIS)

A fluidic oscillator was investigated for use in measuring fuel-air ratios in hydrocarbon combustion processes. The oscillator was operated with dry exhaust gas from an experimental combustor burning ASTM A-1 fuel. Tests were conducted with fuel-air ratio...

S. M. Riddlebaugh

1974-01-01

126

Combustion-generated indoor air pollution. I. Field measurements 8\\/75--10\\/75  

Microsoft Academic Search

The indoor air quality of six homes with gas and electric cooking and gas heating appliances was characterized to determine the level of gaseous and aerosol air pollutants from typical indoor combustion sources. Field measurements of SO, NO\\/NO, O, and CO were determined on a continuous basis. Total aerosol samples were collected on filter media for laboratory analysis by X-ray

C. D. Hollowell; R. J. Budnitz; G. D. Case; G. W. Traynor

1976-01-01

127

A new double-cathode ionic air flowmeter for internal combustion engines  

Microsoft Academic Search

A very quick response air mass flowmeter for accurate measurement of intake air in internal combustion engines was developed. This flowmeter consists of a disk type anode surrounded by two coaxial cylinders which serve as the first and second cathodes, respectively. Steady state flow tests show this flowmeter has sufficient accuracy, linearity, and directivity and no hysteresis was observed. The

M. Tanaka; U. Kitajima; S. Doi; T. Sato

1988-01-01

128

Release of chemical energy by combustion in a supersonic mixing layer of hydrogen and air  

Microsoft Academic Search

The process involved in chemical energy release by combustion in a supersonic, constant pressure, hydrogen-air laminar mixing layer was studied computationally, with a chemical kinetics model involving nineteen reactions and eight species. To try to find out the physical reason for the different trends of the pressure curves observed in an experimental supersonic combustor at two different initial air stream

J. H. Tien; R. J. Stalker

2002-01-01

129

Apparatus for controlling the ratio of air to fuel quantity in internal combustion engines  

SciTech Connect

An apparatus is proposed which serves to control the ratio of air to fuel quantity of the operational mixture to be introduced into the combustion chambers of an internal combustion engine. The actual fuel quantity supplied via an injection apparatus and the actual air quantity supplied via the intake manifold of the engine are measured and processed in a control apparatus into a correction adjusting variable. The apparatus further functions with exhaust recirculation, with the aspirated fresh air quantity being dosed and the remnant filling of the gaseous filling introduced into the combustion chambers of the engine is replaced by recirculated exhaust gas. For the purpose of dosing the fresh air, a symmetrical throttle valve is disposed in the intake manifold, whose position is transferred by means of pneumatic servomotor to a second throttle device, by means of which finally the quantity of the recirculated exhaust gas is determined.

Walz, L.; Wessel, W.

1981-12-22

130

Pulse Combustion Control Technology for Oxygen Atmosphere  

Microsoft Academic Search

A new combustion control method for oxygen-enriched or pure-oxygen ceramic roller kilns is proposed in this paper. This kind of roller kiln uses high-concentration oxygen or pure oxygen as the combustion-supporting medium. The new method introduces the pulse combustion control technology into the ceramic roller kiln to fine tune its oxygen-and-gas proportional regulator. This technology can greatly improve the combustion

Chen Jing; Huang Bihui; Yuan Youxin; Chun Xiao; Xiang Kui

2009-01-01

131

Influence of low air pressure on combustion characteristics and flame pulsation frequency of pool fires  

Microsoft Academic Search

To investigate the effect of low air pressure on the combustion characteristics and puffing flame frequency of pool fires, ethanol and n-heptane pool fires were performed using 15 square burners of various size in both Lhasa (altitude: 3650m; air pressure: 65kPa) and Hefei (altitude: 24m, air pressure: 100.8kPa) fire laboratories. Comparison of the experimental results for pool fires of the

Jun Fang; Ran Tu; Jin-fu Guan; Jin-jun Wang; Yong-ming Zhang

2011-01-01

132

Plasma ignition of combustion in a supersonic flow of fuel-air mixtures: Simulation problems  

Microsoft Academic Search

Theoretical and experimental approaches to tackling the problems of plasma ignition of supersonic combustion in fuel-air mixtures\\u000a of various compositions are discussed. Discharge types useful for this purpose are considered. The feasibility of reaching\\u000a a substantial gain in energy in the initiation of combustion by non-equilibrium gas-discharge plasma is particularly interesting.

I. V. Kochetov; A. P. Napartovich; S. B. Leonov

2006-01-01

133

Experimental Study of the Disperse Composition of Condensed Products of Aluminum?Particle Combustion in Air  

Microsoft Academic Search

The particle shape and structure and also the disperse composition of condensed products of combustion of ASD-1, ASD-4 and ASD-6 aluminum-based powders in air with oxidizer-to-fuel ratios of 0.12–0.4 and initial pressures of 0.05–0.30 MPa are examined. The mass of submicron particles of aluminum oxide amounts to 90% of the total mass of condensed combustion products. The mean mass diameter

D. A. Yagodnikov; E. I. Gusachenko

2004-01-01

134

Laser-based imaging measurements in combustion: New results for fuel\\/air mixture and temperature diagnostics  

Microsoft Academic Search

Advanced laser-based imaging diagnostics is an important tool for the development and optimization of modern combustion devices that can fulfil the future requirements in terms of energy efficiency maximization and pollutant minimization. The determination of the conditions prior to combustion in terms of fuel concentration, fuel\\/air equivalence ratio and temperature is crucial for the control of the subsequent combustion process.

C. Schulz

2006-01-01

135

The application of new combustion and turbulence models to H[sub 2]-air nonpremixed supersonic combustion  

SciTech Connect

Finite reaction rate effects and dilatation effects are explored using an extended laminar flamelet model and turbulence models including dilatation processes. For the H[sub 2]-air nonpremixed turbulent combustion experiment conducted by Evans et al. in a high-speed shear flow, the flamesheet model can reasonably predict the combustion region but fails to predict the profiles of mass fractions, especially for H[sub 2] near the jet axis and O[sub 2] close to the jet edge. The inclusion of both dilatation dissipation and pressure dilatation leads to no significant improvement of the simulation results in this relatively low Mach number test case. The results predicted by the laminar flamelet model dramatically improve the profiles of species mass fractions. This indicates that the high turbulent strain rate usually observed in high-speed flow has a significant influence on the turbulent combustion. The widely used assumptions, such as fast chemical reaction rate, and unity Prandtl and Lewis numbers, are not suitable for this high-speed turbulent flow. It is necessary to include effects of kinetic energy changes in the calculations. Numerical results also show that this supersonic nonpremixed turbulent combustion flow satisfies the criteria of the laminar flamelet model.

Zheng, L.L.; Bray, K.N.C. (Cambridge Univ. (United Kingdom). Dept. of Engineering)

1994-11-01

136

Internal combustion engine with compressed air collection system  

Microsoft Academic Search

This patent describes an internal combustion engine comprising cylinders respectively including a pressure port, pistons respectively movable in the cylinders through respective compression strokes, fuel injectors respectively connected to the cylinders and operative to supply, from a fuel source to the respective cylinders, a metered quantity of fuel conveyed by compressed gas in response to fuel injector operation during the

1988-01-01

137

Electric air preheater for an internal combustion engine  

Microsoft Academic Search

A preheater adapted to be connected to an internal combustion engine is described comprising a hollow cylinder, a cover element at each end of the hollow cylinder. The hollow cylinder and cover elements collectively defining an elongate closed heating chamber, an elongate electric heating element in the form of a cylindrical rod supported by the cover element at one end

L. J. Chen; T. P. Hsiang

1986-01-01

138

Combustion of large aluminum particles in an air flow  

Microsoft Academic Search

In fl-5], much information was given on the conditions of combustion of aluminum particles, generally in the form of an additive to rocket fuel. The form of the initial aluminum particles determined the kind of investigations carried out, the reaction medium, and also the disperse composition of the particles, which ranged from one to a few hundred microns in size.

G. I. Smelkov; A. A. Aleksandrov; V. A. Pekhotikov; E. V. Grishin

1978-01-01

139

Numerical Calculations of Hydrogen-Air Combustion (PWR; BWR).  

National Technical Information Service (NTIS)

One serious concern during the accident at Three Mile Island resulted from the generation of a large amount of hydrogen gas and its migration to the containment building. The fear was that combustion of this hydrogen could produce pressures that would bre...

P. J. O'Rourke

1983-01-01

140

Numerical calculations of hydrogen-air combustion. [PWR; BWR  

Microsoft Academic Search

One serious concern during the accident at Three Mile Island resulted from the generation of a large amount of hydrogen gas and its migration to the containment building. The fear was that combustion of this hydrogen could produce pressures that would breach containment. The Center for Nonlinear Studies at Los Alamos is sponsoring an effort to assess the Laboratory's current

ORourke

1983-01-01

141

A new double-cathode ionic air flowmeter for internal combustion engines  

SciTech Connect

A very quick response air mass flowmeter for accurate measurement of intake air in internal combustion engines was developed. This flowmeter consists of a disk type anode surrounded by two coaxial cylinders which serve as the first and second cathodes, respectively. Steady state flow tests show this flowmeter has sufficient accuracy, linearity, and directivity and no hysteresis was observed. The effects of temperature, pressure, and humidity of the air were studied. For pulsating air flow this flowmeter showed excellent dynamic response. Furthermore, this meter succeeded in measuring the intake air flow rate of a single cylinder spark ignition engine under firing conditions. Therefore, this flowmeter is very useful not only for analyzing the transient characteristics of internal combustion engines, but also for the accurate control of the fuel injection systems of gasoline engines.

Tanaka, M.; Kitajima, U.; Doi, S.; Sato, T.

1988-01-01

142

Effects of Addition of Carbon Dioxide on Thermal Characteristics in Oxygen-Enriched Hydrogen Flame  

NASA Astrophysics Data System (ADS)

An experimental study has been conducted to evaluate the effects of CO2 addition on thermal behavior in oxygen-enriched hydrogen flame. Experiments were performed on flames stabilized by a co-flow swirl burner, which was mounted on top of the furnace. Several different oxidizer compositions were prepared by volumetrically replacing N2 by CO2. In a steady state, the total as well as radiative heat flux from the flame to the wall of furnace has been measured using a heat flux meter. Temperature distribution in furnace has been also measured and compared. By increasing CO2 proportion in the oxidizer, the convection became to play a more significant role rather than radiation due to heat blockage effect. Overall temperature in the furnace was seen to decrease, while the total heat flux has increased.

Lee, Chang Yeop; Baek, Seung Wook; Choi, Joon Won

143

High energy combustion air nozzle and method for improving combustion in chemical recovery boilers  

SciTech Connect

This patent describes an apparatus for improving the delivery of airflow from a wind box into a combustion chamber. It comprises: a nozzle extending through the wind box and having a convergent portion; and a damper section positioned outside of the wind box, the damper section defining an airflow path from inside the wind box into the nozzle, wherein the nozzle interconnects the damper section and a port leading into the combustion chamber, the convergent portion of the nozzle accelerating the airflow delivered into the chamber.

Jansen, J.H.

1990-07-10

144

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

SciTech Connect

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

Yungster, S.; Rabinowitz, M.J. (NASA, Lewis Research Center, Cleveland, OH (United States))

1993-06-01

145

Combustion of lean prevaporized fuel–air mixtures mixed with hot burned gas for low-NO x emissions over an extended range of fuel–air ratios  

Microsoft Academic Search

Reaction of lean to ultra-lean mixtures supported by high-temperature burned gas can resolve the dilemma between complete combustion versus ultra-low NOx emissions in lean premixed gas turbine combustors. The combustion characteristics and NOx emissions in “lean–lean” two-stage combustion were investigated for premixed–prevaporized kerosene–air mixtures using a co-axial flow configuration. Secondary prevaporized kerosene–air mixtures of lean to ultra-lean compositions were injected

Naoki Aida; Tomoki Nishijima; Shigeru Hayashi; Hideshi Yamada; Tadashige Kawakami

2005-01-01

146

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

SciTech Connect

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.

Matheaus, A.C.

1996-09-01

147

Device for admitting exhaust gases and fuel-air mixtures into the cylinders of an internal combustion engine  

SciTech Connect

A device is proposed for the supply of operating air-fuel mixtures including exhaust gases to internal combustion engines. Between the opening periods of the inlet valves of an internal combustion engine, precisely dispensed quantities of recirculated exhaust gas are pre-stored in the intake channel directly upstream of the inlet valve whereby a stratification of exhaust gas and fuel-air mixture in the combustion chamber of the engine is obtained.

Eckert, K.; Britsch, H.; Linder, E.; Muller, K.; Polach, W.

1984-10-09

148

Fuel and air supply system for combustion based power sources  

Microsoft Academic Search

The paper describes the components of a fuel and air supply system for a micro combustor. Liquid gas from a fuel cartridge is regulated by a micro valve, ejected from a nozzle, and then supplied, with air, to a micro combustor. The valve is composed of a largely-deformable corrugated diaphragm regulating fuel gas and two electrostatic valves controlling the corrugated

Daisuke Satoh; Shuji Tanaka; Masayoshj Esashi

2005-01-01

149

Air void system in concrete containing circulating fluidized bed combustion fly ash  

Microsoft Academic Search

The increased use of advanced coal-burning technologies for power generation, such as circulating fluidized bed combustion\\u000a (CFBC), results in new waste products. The potential for using CFBC fly ash in air-entrained concrete was investigated in\\u000a order to assess the influence of CFBC fly ash on the microstructure of air voids in hardened concrete. A special specimen\\u000a surface preparation technique for

Michal A. Glinicki; Marek Zielinski

2008-01-01

150

Combustion Turbine Inlet Air Cooling (CTIAC): Benefits, Technology Options, and Applications for District Energy  

Microsoft Academic Search

Combustion turbines (CTs) are increasingly used for electric power generation in combined heat & power (CHP) applications, including those in the district energy arena. CTs exhibit an inherent loss in power output as ambient air temperature rises, at precisely those times when power is most in demand and most highly valued.This article presents the concepts, and the benefits, of cooling

John S. Andrepont

2001-01-01

151

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...

152

Fuzzy rule-based combustion control on air adjustment applied to a coal fired power plant  

Microsoft Academic Search

Fuzzy modelling and control is a technique to handle qualitative information in a formal, rigorous and efficient way if such information is properly used. In this paper it is presented an alternative fuzzy logic rule-based method to correct the excess air flow to the combustion furnace of a large coal fire boiler. The developed algorithm for decision on the control

Ramdn Ferreiro Garcia

1994-01-01

153

Plasma Combustion of Ethanol\\/Air Mixture in The Transverse Arc  

Microsoft Academic Search

The influence of preliminary plasma reforming of fuel on plasma combustion efficiency was investigated. The ethanol was chosen as researched fuel. The electrical discharge in the gas channel with a liquid wall was used for preliminary ethanol reforming. The burning was supported by transverse arc discharge in a flow of mix air + reformed ethanol. Emission spectroscopy of plasma was

V. Yukhymenko; V. Chernyak; V. Naumov; Iu. Veremii; V. Zrazhevskij

154

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 ...

155

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...

156

Study of air swirl and particle movement in diesel combustion chambers  

Microsoft Academic Search

A report is presented on the results of an investigation of the air swirl and the particle movement in the combustion chamber of a D.I. diesel engine. The particle track method is used in the visualization of the flow phenomena. The experimental results show that this method can be satisfactorily used in this field provided that the tracer particles selected

S. X. Shi; S. L. Liu

1981-01-01

157

Laser spark ignition and combustion characteristics of methane-air mixtures  

SciTech Connect

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.

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

1998-03-01

158

Combustion air preheating for refinery heaters using plate-type heat exchangers  

SciTech Connect

Combustion air preheating by recovering heat from combustion gases is a cost effective method of increasing the overall thermal efficiency of the refining and petrochemical processes. This paper presents the advantages of the plate-type air preheaters made of smooth plates without extended surfaces. These exchangers provide a relatively high heat transfer coefficient at a relatively low pressure drop, resulting in a flexible and compact design. The air preheater design can easily be integrated into the heater design. Top mounting with natural draft becomes possible for many applications, eliminating the need for I.D. fan and expensive ductwork. The economical extent of heat recovery function of the fuel fired is presented based on practical experience. The use of porcelain enameled (glass coated) plates and of stainless steel materials allows the operation of the air preheater below the acidic and water dew point. Finally the paper presents the experience of the Canadian refineries and petrochemical plants with plate-type heat exchangers used for combustion air preheating.

Dinulescu, M.

1987-01-01

159

Radiation damage studies on MCz and standard and oxygen enriched epitaxial silicon devices  

NASA Astrophysics Data System (ADS)

N-type epitaxial layers of 72 ?m thickness and a resistivity of 150 ? cm have been grown on highly Sb-doped Cz-substrates at ITME (Warsaw). The diode processing was performed at CiS-Erfurt. For comparison a batch of 280 ?m thick n-type MCz wafers with a resistivity of >600 ? cm from Okmetic (Finland) was added to the process run. Depth profiles of the oxygen and carbon concentration were measured via the SIMS-method on as grown epi-layers and after different device-process steps at CiS including an oxygen enrichment at 1100 °C for 24 h. For the MCz material the profiles were measured on untreated samples and after the full device process. Irradiation runs were performed with neutrons at the TRIGA reactor of Ljubljana up to a fluence value of 1016 cm-2. The development of the macroscopic device parameters (effective doping concentration and charge collection for ?-particles) as function of fluence is presented for the standard and oxygenated epi-devices and compared with the MCz-diodes. The results are discussed in the frame of defect studies resulting from TSC-measurements.

Fretwurst, E.; Hönniger, F.; Kramberger, G.; Lindström, G.; Pintilie, I.; Röder, R.

2007-12-01

160

Chaotic dynamics in premixed hydrogen\\/air channel flow combustion  

Microsoft Academic Search

The complex oscillatory behaviour observed in fuel-lean premixed hydrogen\\/air atmospheric pressure flames in an open planar channel with prescribed wall temperature is investigated by means of direct numerical simulations, employing detailed chemistry descriptions and species transport, and nonlinear dynamics analysis. As the inflow velocity is varied, the sequence of transitions includes harmonic single frequency oscillations, intermittency, mixed mode oscillations, and

Gianmarco Pizza; Christos E. Frouzakis; John Mantzaras

2011-01-01

161

Chaotic dynamics in premixed hydrogen\\/air channel flow combustion  

Microsoft Academic Search

The complex oscillatory behaviour observed in fuel-lean premixed hydrogen\\/air atmospheric pressure flames in an open planar channel with prescribed wall temperature is investigated by means of direct numerical simulations, employing detailed chemistry descriptions and species transport, and nonlinear dynamics analysis. As the inflow velocity is varied, the sequence of transitions includes harmonic single frequency oscillations, intermittency, mixed mode oscillations, and

Gianmarco Pizza; Christos E. Frouzakis; John Mantzaras

2012-01-01

162

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...

163

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

SciTech Connect

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

Szpunar, C.B.

1992-09-01

164

Apparatus for controlling the air-fuel quantity ratio in internal combustion engines  

SciTech Connect

An apparatus is disclosed for controlling the ratio of air to fuel quantity of the operational mixture to be introduced into the combustion chambers of an internal combustion engine which includes an air flow rate meter moving under differential pressure against a constant hydraulic restoring force, which air flow rate meter adjusts a metering cross section in a supply line leading to a fuel injection pump, with the pressure drop at the metering cross section being maintained constant with the aid of a differential pressure valve. The air flow rate meter is part of a known apparatus which controls the fuel component in accordance with the quantity of aspirated air and also controls the component of exhaust gas to be fed back. The hydraulic restoring pressure for the air flow rate meter is drawn via a throttle from the supply side of a supply pump which supplies the injection pump with fuel under an rpm-dependent pressure and with a quantity of fuel intended for flushing and the pressure downstream of the throttle is maintained at a constant value by means of a pressure maintenance valve. The working chambers of the injection pump communicate only with either the injection lines or the fuel supply line controlled by the air flow rate meter, so that the control result is not adulterated by the flushing quantity or by a shutoff quantity. In this manner, the injection pump and the control device can be supplied with fuel and with pressure fluid by means of a single supply pump.

Stumpp, G.

1981-08-18

165

Effects of air preheating on emissions of NO, HCN and NHâ from a two-stage combustion. [Zeldovich mechanism  

Microsoft Academic Search

The purpose of this study is to investigate the effects of air preheating on the emissions of NO, HCN and NHâ from an ordinary single-stage combustion and a two-stage combustion, with the hope of finding an ideal combustion method which can realize both energy savings and NO\\/sub x\\/ reduction. Two approaches were used to carry out this study. One approach

M. Sadakata; Y. Fujioka; D. Kunii

1981-01-01

166

CFD modelling of air-fired and oxy-fuel combustion of lignite in a 100 KW furnace  

Microsoft Academic Search

In this paper, a comprehensive computational fluid dynamics (CFD) modelling study was undertaken by integrating the combustion of pulverized dry lignite in several combustion environments. Four different cases were investigated: an air-fired and three different oxy-fuel combustion environments (25vol.% O2 concentration (OF25), 27vol.% O2 concentration (OF27), and 29vol.% O2 concentration (OF29) were considered. The chemical reactions (devolatilization and char burnout),

Audai Hussein Al-Abbas; Jamal Naser; David Dodds

2011-01-01

167

Hydrogen:air:steam flammability limits and combustion characteristics in the FITS (Fully Instrumented Test Site) vessel  

Microsoft Academic Search

For the past few years,the United States Nuclear Regulatory Commission has sponsored research at Sandia National Laboratories addressing the combustion characteristics and flammability limits of combustible atmospheres that might occur inside containment during a loss-of-coolant accident inside a pressurized water reactor (PWR). Combustion of certain hydrogen:air:steam atmospheres could, at least hypothetically, threaten the integrity of the containment structure. To assist

B. W. Jr

1986-01-01

168

Autoignition and combustion of water-fuel emulsion during its injection into heated air. III. Completeness of combustion of fuel oil M-40  

Microsoft Academic Search

The dependence of the completeness of combustion of liquid fuel during its pulsed injection into heated air on the parameters\\u000a of the medium and delivery conditions was established experimentally and it is shown that emulsification of the fuel does\\u000a not affect the integral completeness of combustion. Therefore, an increase of fuel economy of diesel engines on converting\\u000a them to a

A. A. Buzukov; B. P. Timoshenko

1995-01-01

169

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

Microsoft Academic Search

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

1975-01-01

170

Effect of combustion chamber configuration on in-cylinder air motion and combustion characteristics of D. I. diesel engine  

Microsoft Academic Search

A new combustion system for a light duty D.I. diesel engine was developed and introduced. The combustion chamber, which was used in the combustion system, has 4 concaves on the periphery of the inner wall and was called HMMS-III. This combustion chamber realized better fuel consumption and lower smoke level over a wide speed range. In this study, in order

M. Shimoda; M. Shigemori; S. Tsuruoka

1985-01-01

171

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

SciTech Connect

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.

Yungster, S.; Rabinowitz, M.J.

1993-06-01

172

Fuel-air mixing and diesel combustion in a rapid compression machine  

SciTech Connect

The influence of charge motion and fuel injection characteristics on diesel combustion was studied in a rapid compression machine (RCM), a research apparatus that simulates the direct-injection diesel in-cylinder environment. An experimental data base was generated in which inlet air flow conditions (temperature, velocity, swirl level) and fuel injection pressure were independently varied. High-speed movies using both direct and shadowgraph photography were taken at selected operating conditions. Cylinder pressure data were analyzed using a one-zone heat release model to calculate ignition delay times, premixed and diffusion burning rates, and cumulative heat release profiles. The photographic analysis provided data on the liquid and vapor penetration rates, fuel-air mixing, ignition characteristics, and flame spreading rates. Results show that charge temperature is the most significant parameter controlling the ignition delay period and it significantly affects the heat release profile in the premixed combustion phase.

Balles, E.N.; Heywood, J.B.

1988-01-01

173

Effect of air preheating and fuel moisture on combustion characteristics of corn straw in a fixed bed  

Microsoft Academic Search

Experiments were carried out on a one-dimensional bench combustion tests rig. The effect of air preheating and moisture level in the fuel on combustion characteristics of corn straw was investigated. The bed temperature distribution and the mass loss of fuel and gas components such as O2, CO, CO2 and NO were measured in the bed. The average burning rate and

Wei Zhao; Zhengqi Li; Guangbo Zhao; Fangshi Zhang; Qunyi Zhu

2008-01-01

174

Dilution limits of n-butane\\/air mixtures under conditions relevant to HCCI combustion  

Microsoft Academic Search

The role of a spark discharge in extending the operating limits of homogeneous change compression ignition (HCCI) combustion has been investigated using engine experiments and computational flame modeling. The flammability limits of ultra-dilute n-butane\\/air mixtures are calculated over ranges of temperature, pressure, and dilution levels relevant to HCCI operation. The results suggest that with the elevated temperatures required to achieve

Y Huang; C. J Sung; J. A Eng

2004-01-01

175

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

Microsoft Academic Search

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

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

2009-01-01

176

HMX flame structure for combustion in air at a pressure of 1 atm  

Microsoft Academic Search

The chemical structure of HMX flame during combustion in air at a pressure of 1 atm was calculated using molecular beam mass\\u000a spectrometric sampling. HMX vapor was recorded for the first time near the burning surface. A total of 11 species were identified\\u000a in the HMX flame (H2, H2O, HCN, N2, CO, CH2O, NO, N2O, CO2, NO2, and HMX vapor),

A. A. Paletsky; E. N. Volkov; O. P. Korobeinichev

2008-01-01

177

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

Microsoft Academic Search

Acetone planar laser induced fluorescence (PLIF) and particle image velocimetry (PIV) are used to investigate pre-combustion fuel-air mixing in an optically accessible single-cylinder engine fueled with hydrogen. PLIF and PIV are acquired separately in a plane parallel to the piston top ( r-? plane) at a fixed engine speed and crank angle. The experiments include measurements for non-fueled engine operation

Christopher M. White; Sebastian Kaiser; Michael Roux

2008-01-01

178

Completeness of Combustion for Laminar Wall Fires Using Several Alcohols Burning in Air  

Microsoft Academic Search

Steady, fully-burning wall fires were studied for several alcohols burning in air. Methanol, 1-propanol. and 1-butanol were burned using a vertically-oriented porous ceramic wick. Completeness of combustion was evaluated and accounting for its effect in numerical modeling, on characteristics of laminar wall fires was examined. Measurements of the concentration profiles in the free-convection boundary layers formed revealed that for each

STEVEN F. MALARY; JEAN K. AWAD; RAJENDER THAPAR

1989-01-01

179

Inhibition of various hydrogen combustion regimes in air by Propylene and Isopropanol  

Microsoft Academic Search

This paper studies the effects of small additives of propylene and isopropanol on the hydrogen-air flame speed in the predetonation regime, deflagration-to-detonation transition, and burning rate. It is shown that the difference in the effects of these additives on the combustion is determined primarily by their ability to terminate reaction chains. In hydrogen flames, the additives are consumed as a

V. V Azatyan; A. A. Borisov; A. G. Merzhanov; V. I. Kalachev; V. V. Masalova; A. E. Mailkov; K. Ya. Troshin

2005-01-01

180

Membranes producing nitrogen-enriched combustion air in diesel engines: Assessment via dimensionless numbers  

Microsoft Academic Search

The challenge of reducing nitrogen oxides (NOX) emissions in diesel engine exhaust gas can be met by the use of nitrogen-enriched air (NEA) for combustion. In this work, the separation performance of membranes producing NEA is simulated and experimentally validated. Retentate nitrogen concentration and stage-cut depend on the membrane properties oxygen–nitrogen selectivity, oxygen permeance and membrane area as well as

Marc Ajhar; Michael Follmann; Carsten Matthias; Thomas Melin

2008-01-01

181

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

Microsoft Academic Search

To develop sampling strategies and bioassay protocols for indoor air containing emissions from coal combustion in homes of the rural Xuan Wei County in China, the authors developed a medium-volume sampler to collect the <10-..mu..m particles and semivolatile organics by a filter and an XAD-2 resin, respectively. A high-volume particulate sampler was used for comparison. The coal was burned under

Judy L. Mumford; D. Bruce Harris; Katherine Williams; Jane C. Chuang; Marcus Cooke

1987-01-01

182

Particle combustion rates for mechanically alloyed Al–Ti and aluminum powders burning in air  

Microsoft Academic Search

Mechanically alloyed aluminum-rich powders of Al–Ti (10, 15, 20, and 25 atom% of Ti) were produced and their combustion was compared to that of aluminum and titanium powders of comparable sizes. A laminar lifted-flame aerosol burner developed recently was used in this research. The aerosols were produced and burned in air. Measured flame speeds were higher for the aerosols of

Yuriy L. Shoshin; Edward L. Dreizin

2006-01-01

183

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

DOEpatents

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.

Tuttle, Kenneth L. (Federal Way, WA)

1980-01-01

184

Laminar lean premixed methane/air combustion near the lean flammability limit using nanosecond repetitive pulsed discharge plasmas  

NASA Astrophysics Data System (ADS)

Gas chromatographic and temperature measurements have been carried out to investigate the extent of premixed methane/air combustion with the application of nanosecond repetitive pulsed discharges around the lean flammability limit for laminar flows. The results show that the discharges lead to the complete combustion when the equivalence ratio is above 0.54, but when the ratio is below the limit, the combustion is quenched at the downstream flow. To investigate the kinetics in detail, 2-D simulations of plasma-induced combustion have been conducted for methane/air mixtures at below and above the lean flammability limit. The simulations reveal that methane is mostly combusted in the discharge region since the discharge repetition timescale is much shorter than the species diffusion and advection timescales, and so the discharge serves more as a heat and radical source rather than a small combustor, to flame hold near the lean flammability limit.

Bak, Moon Soo; Do, Hyungrok; Mungal, Mark G.; Cappelli, Mark A.

2011-11-01

185

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

NASA Astrophysics Data System (ADS)

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

Gaffney, Jeffrey S.; Marley, Nancy A.

186

Effect of excess air on the optimization of heating appliances for biomass combustion  

SciTech Connect

The performance of a domestic appliance for wood logs combustion is a function of several variables, such as the geometric design of the appliance and its operating parameters. Among them, air feeding conditions are really decisive if the objective function is the maximization of the heat recovered from flue gases. Therefore, even if pollutant emissions have to be ever considered, the amount of excess air can be seen as a fundamental parameter in the definition of thermal efficiency of the appliance. In this paper the role of this parameter is analysed. The analysis is conducted by linking the results obtained from experimental data, detailed CFD simulations and a simplified mathematical model based on a network of CSTR. The derivation of an idealized schematization of the appliance was essential to realize the role of excess air variations, with more generality than with respect to a specific appliance configuration. Conversely, while the experimental data and CFD results were necessary to derive the simplified model, the indications given by this simplified model were useful to analyze results coming from both experiments and detailed numerical simulations. It has been evidenced the need to distinguish between the role of excess air in the chemical combustion and in the heat recovery in the appliance as well as to quantify the feedback between these two processes. (author)

Menghini, D. [Dipartimento di Ingegneria Chimica, Universita degli studi di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli (Italy); Marra, F.S.; Allouis, C.; Beretta, F. [Consiglio Nazionale delle Ricerche, Istituto di Ricerche sulla Combustione - CNR, via Diocleziano 328, 80124 Napoli (Italy)

2008-07-15

187

Laser Diagnostics of Combustion Enhancement on a CH4/Air Bunsen Flame by Dielectric Barrier Discharge  

NASA Astrophysics Data System (ADS)

We investigate plasma-assisted combustion for premixed CH4/air Bunsen flames. Dielectric barrier discharge (DBD) is employed to produce non-equilibrium plasma for combustion enhancement. The transient planar laser induced fluorescence (PLIF) technique of CH and OH radicals is used to image reaction zones for enhancement measurement, and the emission spectra of the Bunsen flame are monitored to explore the kinetics mechanism. From the drift of radicals in PLIF images, the quantitative enhancement of plasma on the flame velocities of premixed methane/air flames is experimentally measured, and the data show that the flame velocities are increased by at least 15% in the presented equivalence ratio range. Furthermore, the well analyzed emission spectra of the Bunsen flame (300–800 nm) with/without DBD reveal that the emissions as well as the concentrations of the crucial radicals (like C2, CH, OH etc.) in combustion all are intensified greatly by the discharge. In addition, the appearance of excited spectral bands of N2 and N+2 during discharge indicates that the premixed gas is also heated and ionized partially by the DBD.

Zhang, Shao-Hua; Yu, Xi-Long; Chen, Li-Hong; Zhang, Xin-Yu

2013-08-01

188

Hydrogen:air:steam flammability limits and combustion characteristics in the FITS (Fully Instrumented Test Site) vessel  

SciTech Connect

For the past few years,the United States Nuclear Regulatory Commission has sponsored research at Sandia National Laboratories addressing the combustion characteristics and flammability limits of combustible atmospheres that might occur inside containment during a loss-of-coolant accident inside a pressurized water reactor (PWR). Combustion of certain hydrogen:air:steam atmospheres could, at least hypothetically, threaten the integrity of the containment structure. To assist in the resolution of these issues, a series of 239 hydrogen:air:steam combustion experiments was performed in a 5.6 m/sup 3/ vessel. Experimentally observed flammability limits of hydrogen:air:steam mixtures in both turbulent and quiescent environments were measured and a correlation developed that describes the three-component flammability limit. The newly developed correlation can be used to estimate the flammability of a mixture at these scales and larger scales to obtain approximate ignition conditions.

Marshall, B.W. Jr.

1986-12-01

189

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

NASA Astrophysics Data System (ADS)

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.

Zhu, Jianguo; Ouyang, Ziqu; Lu, Qinggang

2013-06-01

190

Combustion  

NSDL National Science Digital Library

In this chemistry activity, learners discover that the weight of the product of combustion is greater than that of the starting material. Learners will compare the weight of steel wool before and after it is heated. Learners are asked to consider why the steel wool weighs more (oxidation) as well as write the balanced chemical equation for the burning of steel. This activity uses an open flame; adult supervision is recommended. The resource includes notes for educators and extension ideas.

House, The S.

2013-05-15

191

Highjacking of Hard-Earned Energy Savings Through The Backdoor—Combustion Air Requirements in Fossil Fuel Installations  

Microsoft Academic Search

Fossil fuels—coal, fuel oil, natural gas, etc.—used in space heating, cooling, processing, and power plants require an appropriate amount of air for complete combustion. It is quite normal to provide some amount of excess air to ensure this process so that there are absolutely no unburnt or partially burnt fuel elements in the exhaust, as would be indicated by carbon

Gary Krishnan

2012-01-01

192

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

NASA Astrophysics Data System (ADS)

Hydrogen gas is burned in air to raise and maintain the stagnation temperature of a supersonic combustion test facility to a desired setpoint. In order to reach the desired operating conditions for stagnation temperature, there are three phases 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 desired temperature setpoint. Each phase incorporates a different type of control. Fuzzy logic is used to design a computer based supervisory controller that recognizes the different phases of operation and chooses the appropriate control method.

Owens, M.; Segal, C.

193

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

PubMed

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

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

194

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

SciTech Connect

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 of any pollution control equipment. Data collected indicate that relatively low levels of organic HAPs are present in the flue gases for any of the combustion conditions; however, several compounds were present that have not been reported in previous studies. To the extent that these small-scale tests accurately simulate full-scale units, estimates based on these experiments indicate that the total HAP emissions from a large utility power plant are not likely to increase significantly due to installation of combustion modification techniques for NOx control.

Miller, C.A.; Srivastava, R.K.; Ryan, J.V.

1994-01-01

195

Effects of air\\/fuel combustion ratio on the polycyclic aromatic hydrocarbon content of carbonaceous soots from selected fuels  

Microsoft Academic Search

Patterns of polycyclic aromatic hydrocarbon (PAH) content were observed from GC\\/MS analysis of the extracts of soots at various air\\/fuel combustion ratios of three commonly used fuels: n-hexane, JP-8 (Jet fuel), and diesel. With increasing air\\/fuel ratio, from a simple diffusion flame up to an air\\/fuel ratio of 3.94, there is a significant loss of high molecular weight PAHs and

C. C. Jones; A. R. Chughtai; B. Murugaverl; D. M. Smith

2004-01-01

196

Carbon Nanotubes, Nanocrystal Forms, and Complex Nanoparticle Aggregates in common fuel-gas combustion sources and the ambient air  

Microsoft Academic Search

Aggregated multiwall carbon nanotubes (with diameters ranging from ?3 to 30nm) and related carbon nanocrystal forms ranging in size from 0.4 to 2 ?m (average diameter) have been collected in the combustion streams for methane\\/air, natural gas\\/air, and propane gas\\/air flames using a thermal precipitator. Individual particle aggregates were collected on carbon\\/formvar-coated 3mm nickel grids and examined in a transmission

L. E. Murr; J. J. Bang; E. V. Esquivel; P. A. Guerrero; D. A. Lopez

2004-01-01

197

Using air pressure--mechanical atomising burners to improve combustion of oil in gas turbine plant combustors  

Microsoft Academic Search

The design and performance testing of an air pressure--mechanical atomizing burner for improving oil combustion in gas turbine (GT) power plant combustors are described. From these tests it was concluded that the use of the air pressure--mechanical atomizing burner with a pressure drop of the atomizing air in the burner of ..delta..p\\/sub b\\/ of 0.13 to 0.2 MPa and its

A. G. Tumanovskii; I. F. Pshenisnov; V. G. Gabbasov

1976-01-01

198

Air Fractionation by Adsorption  

Microsoft Academic Search

Pressure swing adsorption (PSA) processes for air separation differ by the modes and conditions of operation of the adsorption, the desorption, and the complementary steps, as well as by the types of adsorbents used. Three commercial PSA processes for air separation are reviewed and compared. The first process uses a zeolitic adsorbent and produces only an oxygen-enriched product gas. The

Shivaji Sircar

1988-01-01

199

Air fractionation by adsorption  

Microsoft Academic Search

Pressure swing adsorption (PSA) processes for air separation differ by the modes and conditions of operation of the adsorption, the desorption, and the complementary steps, as well as by the types of adsorbents used. Three commercial PSA processes for air separation are reviewed and compared. The first process uses a zeolitic adsorbent and produces only an oxygen-enriched product gas. The

Sircar

2009-01-01

200

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

Microsoft Academic Search

Combustion emissions account for over half of the fine particle (PM2.5) 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

Joellen Lewtas

2007-01-01

201

A review of inlet air-cooling technologies for enhancing the performance of combustion turbines in Saudi Arabia  

Microsoft Academic Search

Peak demand for electric power in Saudi Arabia occurs during the middle of the day in summer and is almost double the off-peak demand. The demand profile is ill-matched to the performance profile of combustion turbines as their power output decreases with increased inlet-air temperature. Approximately 42% of the Saudi Electric Company’s (SEC) annual energy sales are generated by combustion

Abdulrahman M. Al-Ibrahim; Abdulhadi Varnham

2010-01-01

202

Influence of primary air ratio on flow and combustion characteristics and NO x emissions of a new swirl coal burner  

Microsoft Academic Search

Cold airflow experiments on a small-scale burner model, as well as in situ experiments on a centrally fuel-rich swirl coal combustion burner were conducted. Measurements were taken from within a 300 MWe wall-fired pulverized-coal utility boiler installed with eight of centrally fuel-rich swirl coal combustion burners in the bottom row of the furnace during experiments. Various primary air ratios, flow characteristics,

Jianping Jing; Zhengqi Li; Qunyi Zhu; Zhichao Chen; Feng Ren

2011-01-01

203

Computational modeling of n-heptane droplet combustion in air–diluent environments under reduced-gravity  

Microsoft Academic Search

The combustion and extinguishment of n-heptane droplets in air–diluent environments under reduced-gravity are studied, where carbon dioxide, helium and xenon are used as diluents. A gasification model employing the volume of fluid (VOF) method was developed and implemented into the CFD package FLUENT. The droplet evaporation, combustion and parasitic current were validated by comparing with the previous study. The numerical

Y. Jin; B. D. Shaw

2010-01-01

204

Effect of constant and pulsed-periodic electric fields on combustion of a propane-air mixture  

Microsoft Academic Search

The effect of constant and pulsed periodic electric fields on combustion of a propane-air mixture is studied experimentally.\\u000a The experiments are performed for the laminar and turbulent combustion modes with flame stabilization by a separation region\\u000a behind a central body. The constant and pulsed-periodic electric fields are found to exert different effects on the burning\\u000a rate.

A. F. Garanin; P. K. Tret’yakov; A. V. Tupikin

2008-01-01

205

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

NASA Astrophysics Data System (ADS)

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.

Jia, Li; Li, Jianshu

2004-11-01

206

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

NASA Astrophysics Data System (ADS)

Historic time series (1970-2006) emissions of greenhouse gases and air pollutants arising from stationary and mobile combustion sources were estimated at national level for Argentina and at regional level for the metropolitan area of Buenos Aires (MABA). All emissions were estimated using a bottom-up approach following the IPCC good practice guidance. For mobile sources, national emissions include all transport categories. Regional emissions account thus far only for on-road. For national emissions, methodologies and guidance by the IPCC were employed, applying the highest possible tier and using: i)country-specific emission factors for carbon and sulphur and technology-based information for other species, ii)activity data from energy balance series (1970-2007), and iii)complementary information concerning the non-energy use of fuels. Regional emissions in 2006 were estimated in-depth using a technology-based approach for the city of Buenos Aires (CBA) and the 24 neighboring districts composing the MABA. A regional emissions factors database was developed to better characterize Latin American fleets and driving conditions employing COPERT III-IV algorithms and emission factors measured in dynamometers and circulating vehicles in Argentina, Brazil, Chile and Colombia. Past emissions were back estimated from 2005 to 1970 using the best available information, which differs greatly among categories, spatial disaggregation and time periods. The time series of stationary and mobile combustion sources at the national and regional level allowed the identification of distinct patterns. National greenhouse gas emissions in 2006 amounted to ~ 150 million ton CO2-equivalent, 70% of which were contributed by stationary sources. On-road transport was the major contributor within mobile sources (28.1 %). The increasing emissions trends are dominated by on-road transport, agriculture and residential categories while the variability is largely associated with energy industries. National emissions of air pollutants were in the order: CO > NOx > HCNM > SO2. The small decrease in CO emissions of ~3% is associated with fuel switching from gasoline to compressed natural gas in road-transport, while the marked increase in SO2 emissions of ~34% can be linked to fuel switching from liquid fuels to natural gas in stationary combustion. With regards to regional emissions, mobile sources constitute the ‘high’ emitter. Our estimates for on-road mobile emissions point out the role of MABA and of the City of Buenos Aires as a concentrated site of pollutant emissions (ton CO km-2, year 2000): 0.7 (country-wise) << 122 (MABA) < 815 (CBA), being traffic the main source of pollutants in urban agglomerations.

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

2010-12-01

207

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

SciTech Connect

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

Zhao, Y.C.; Frey, H.C. [CALTECH, Pasadena, CA (United States). Division of Chemical & Chemical Engineering

2006-12-15

208

Effect of vitiated air on the combustion of pulverized coal for applications to coal fired combined cycle steam generators  

SciTech Connect

A 15 Kg/h pulverized fuel two dimensional furnace was used to determine combustion efficiency, ignition stability, CO, C/sub m/H/sub n/, NO/sub x/ profiles of experimental combustors under oxygen-lean and variable excess vitated air conditions for applications to gas turbine-steam turbine combined engines. A domestic bituminous coal mined in Sardegna was investigated. Results show that the total vitiated air excess must be maintained above 30% and oxygen content in the primary stream cannot drop below 17% to avoid a carbon loss of over 3% wt. and unsteady flame formation. The secondary air oxygen content has a lesser influence on combustion efficiency: the tests performed show that an amount of 15% oxygen is sufficient to support a steady flame with over 0.97 combustion efficiency, if the proper swirl generator is used and the total excess of oxidizer is above the limit of 30%. 8 refs.

Floris, F.

1980-01-01

209

Influence of Two-Stage Air Injection Conditions on NOx and Unburned Carbon of Sub-Bituminous Coal Combustion  

NASA Astrophysics Data System (ADS)

Because of large recoverable reserves, sub-bituminous coal is an important energy resources. The disadvantage of sub-bituminous coal is that it contains more than 20% moisture. This makes ignition less efficient. And combustion flame became diffused. Both emissions of NOx and unburned carbon in fly ash become high. We have already shown that these emissions can be reduced by adjusting the air injection conditions from the burner to better suit sub-bituminous coal combustion. However, the reduction is insufficient compared with bituminous coal combustion. In this investigation, influence of two-stage air injection conditions on NOx and unburned carbon concentration in fly ash was studied and the optimum air injection conditions necessary in order to reduce those emissions were clarified.

Ikeda, Michitaka; Makino, Hisao; Morinaga, Hideki; Higashiyama, Koichi

210

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

SciTech Connect

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.

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

211

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

PubMed

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 m3 d(-1), consistent with previous studies employing these samplers. PCN air concentrations exhibited strong urban-rural differences-typically a few pg m(-3) at rural sites and an order of magnitude higher at urban sites (Toronto, 12-31 pg m(-3) and Chicago,13-52 pg m(-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. PMID:16999107

Harner, Tom; Shoeib, Mahiba; Gouin, Todd; Blanchard, Pierrette

2006-09-01

212

Nitride formation during combustion of Ti-TiO 2 and Ti-Al powder mixtures in air under SHS conditions  

Microsoft Academic Search

Nitride formation during SHS combustion of a micron-size titanium powder and its mixtures with additives in air was studied.\\u000a It was shown that the yield of TiN Ti powder was higher for SHS combustion in air than for SHS combustion of powders of the\\u000a same degree of dispersion in nitrogen. The mechanism of formation of TiN is probably determined by

Yu. I. Strokova; A. A. Gromov; M. Yu. Ponomareva; V. I. Vereshchagin

2008-01-01

213

A novel microwave plasma combustor toward understanding plasma assisted ignition and plasma assisted combustion of methane/air mixtures  

NASA Astrophysics Data System (ADS)

A novel microwave plasma combustor has been developed to study mechanisms of plasma-assisted ignition (PAI) and plasma-assisted combustion (PAC). The system allows us to inject a 2.45 MHz atmospheric argon microwave plasma jet directly into a combustion reaction zone to investigate effects of PAI and PAC. Three distinct zones: a pure plasma zone, a plasma-combustion hybrid zone, and a combustion zone are investigated by optical emission spectroscopy (OES) and cavity ringdown spectroscopy (CRDS) of OH, etc. plasma and combustion intermediates. The experimental results allow us to understand the formation of OH radicals and roles of OH in PAI and PAC of methane-air mixtures in a wide range of fuel equivalence ratios ranging from rich to lean burn. A U-curve of plasma power versus fuel equivalence ratio in the PAI of methane-air mixtures is observed. The roles of OH in PAI and PAC of premixed methane-air flames around the flammability limit are discussed.

Wang, Chuji; Wu, Wei

2012-10-01

214

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

Microsoft Academic Search

The amendments to the Clean Air Act (CAA) mandate very strict limits on particulate, smoke, and other emissions from city buses. The use of alternative fuels, such as compressed natural gas (CNG) or methanol, can help transit operators, such as the Chicago Transit Authority (CTA), meet the mandated limits. However, the capital investment needed to convert the fueling infrastructure and

R. R. Sekar; W. W. Marr

1993-01-01

215

Combustion of coal-water slurries  

SciTech Connect

A method of burning a coal-water slurry capable of being retrofitted to oil and gas fired industrial and utility steam boilers or as original equipment in new units using essentially pure oxygen, oxygen-enriched air or hydrogen-oxygen mixtures as the atomizing fluid in a burner atomizer.

Downs, W.; Rackley, J.M.

1985-12-17

216

Combustion of coal-water slurries  

Microsoft Academic Search

A method of burning a coal-water slurry capable of being retrofitted to oil and gas fired industrial and utility steam boilers or as original equipment in new units using essentially pure oxygen, oxygen-enriched air or hydrogen-oxygen mixtures as the atomizing fluid in a burner atomizer.

W. Downs; J. M. Rackley

1985-01-01

217

Monitoring the air fuel ratio of internal combustion engines using a neural network  

NASA Astrophysics Data System (ADS)

Precise control of an internal combustion engine for the reduction of exhaust emissions benefits substantially from accurate measurement of the air-fuel or ? ratio. This paper describes the use of the spark plug as a combustion sensor. The time-varying spark-voltage profile is acquired and used to train a neural network. The neural network is able to estimate the ? ratio. Minimal additional instrumentation is required. Therefore, this method potentially provides a cheap and robust sensor for measuring the ? ratio. The work described here involved devising an appropriate data acquisition system and undertaking experiments to validate the sensor technique. Vectors representing the spark-voltage profile were acquired at three different ? ratio operating points and used to train and test the neural network to ascertain its ability to determine the ? ratio accurately and linearly over a range. The results have supported the application of the spark-voltage profile as a means of ? ratio measurement and the use of neural networks for rapid calibration of engine management systems. Potential benefits and problems of neural network analysis of spark-voltage vectors, as a means of ? ratio estimation by virtual sensing, have been discussed.

Walters, S. D.; DeZoysa, M. M.; Howlett, R. J.

2006-10-01

218

Analytical study of the hydrogen-air reaction mechanism with application to scramjet combustion  

SciTech Connect

A chemical kinetic mechanism for the combustion of hydrogen has been assembled and optimized by comparing the observed behavior as determined in shock tube and flame studies with that predicted by the mechanism. The reactions contained in the mechanism reflect the current state of knowledge of the chemistry of the hydrogen/air system, and the assigned rate coefficients are consistent with accepted values. It was determined that the mechanism is capable of satisfactorily reproducing the experimental results for a range of conditions relevant to scramjet combustion. Calculations made with the reaction mechanism for representative scramjet combustor conditions at Mach 8, 16, and 25 showed that chemical kinetic effects can be important and that combustor models which use nonequilibrium chemistry should be used in preference to models that assume equilibrium chemistry. For the conditions examined the results also showed the importance of including the HO/sub 2/ chemistry in the mechanism. For Mach numbers less than 16, the studies suggest that an ignition source will most likely be required to overcome slow ignition chemistry. At Mach 25, the initial temperature and pressure was high enough that ignition was rapid and the presence of an ignition source did not significantly affect reaction rates.

Jachimowski, C.J.

1988-02-01

219

Effect of vitiated air on the combustion of pulverized coal for applications to coal fired combined cycle steam generators  

Microsoft Academic Search

A 15 Kg\\/h pulverized fuel two dimensional furnace was used to determine combustion efficiency, ignition stability, CO, C\\/sub m\\/H\\/sub n\\/, NO\\/sub x\\/ profiles of experimental combustors under oxygen-lean and variable excess vitated air conditions for applications to gas turbine-steam turbine combined engines. A domestic bituminous coal mined in Sardegna was investigated. Results show that the total vitiated air excess must

Floris

1980-01-01

220

Acoustic Emissions Reveal Combustion Conditions: Turbulent-flame acoustic emissions change with air/fuel ratio variations.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. The acoustic emissions from turbulent gas flames may be useful both for the diagnosis of combustion processes and for fuel/air control. An experimental study has ide...

1984-01-01

221

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

Microsoft Academic Search

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

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

1995-01-01

222

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

NASA Astrophysics Data System (ADS)

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.

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

223

Laser-saturated and linear laser-induced fluorescence measurements of nitric oxide in counterflow diffusion flames under non-sooting oxygen-enriched conditions  

Microsoft Academic Search

We report quantitative, spatially resolved, laser-induced fluorescence (LIF) measurements of NO concentration ([NO]) in non-sooting, oxygen-enriched counterflow diffusion flames at atmospheric pressure. Three different flames containing 25%, 50%, and 100% CH 4 , respectively, in the fuel stream and 100%, 50%, and 35% O 2 , respectively, in the oxidizer stream are investigated at a global strain rate of 20

Sameer V. Naik; Normand M. Laurendeau

2002-01-01

224

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

PubMed

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

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

2009-10-15

225

Liquid fuel combustion apparatus  

Microsoft Academic Search

This patent describes a vaporized liquid fuel combustion apparatus of the type including: a cylinder defining a combustion chamber, the cylinder having an inlet end for receipt of combustion air and an outlet end for exhausting gaseous combustion products; an end plate covering the inlet end of the cylinder; a blower, including a rotor and a casing, for supplying combustion

K. Sawada; Y. Kimijima; H. Umehara

1986-01-01

226

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

SciTech Connect

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.

Grcar, Joseph F; Grcar, Joseph F

2008-06-30

227

Device for regulating the fuel-air ratio in internal combustion engines  

SciTech Connect

A device is proposed for regulating the fuel-air ratio in the operating mixture of an internal combustion engine and for monitoring the operational readiness of a lambda sensor controlling the regulating device and functioning by the principle of ion conduction in solid electrolytes. The lambda sensor has an adjustable, constant reference voltage switched opposite to it. The reference voltage approximately equals the average sensor output voltage. The level of the resultant voltage, which is established with the aid of the resultant current and has values located symmetrically with respect to the reference voltage, is monitored by comparator devices. The output signal of the comparator devices is logically processed and furnishes a signal as to the operational readiness of the sensor. In order to generate the reference voltage, a voltage divider branch having high resistance is disposed parallel to a voltage divider branch of relatively low resistance; the latter voltage divider branch further serves to establish the threshold values of the comparator devices. Because it is independent of the current draw of the comparator devices, the desired reference voltage can be adhered to very precisely, and thus the desired regulating point at which closed-loop control or regulation begins of the regulating device can also be adhered to very precisely.

Drews, U.; Mohrle, W.; Werner, P.

1983-07-19

228

Method and apparatus for regulating the fuel-air ratio in internal combustion engines  

SciTech Connect

A method and an apparatus for regulating the fuel-air ratio of the operational mixture of an internal combustion engine and for monitoring the operational readiness of a lambda sensor controlling the regulating apparatus and functioning according to the principle of ionic conduction in fixed electrolytes. A constant reference voltage which approximately corresponds to the average sensor output voltage is connected opposite to the lambda sensor. The level of the resultant voltage thus established, the values of which are disposed symmetrically relative to the reference voltage, is utilized, along with the cooperation of a resultant electric current which causes a voltage drop across the temperature-dependent internal resistance of the lambda sensor as a gauge for the operational readiness of the lambda sensor. The pickup of the resultant voltage is accomplished by two comparison devices, whose logically evaluatable output signals are transformed via a logical linkage circuit into an operational readiness or unreadiness signal. A third comparison device serves the purpose of controlling the regulating apparatus. The third comparison device output is switched when the lambda sensor is not under the influence of any resultant electric current; as a result, no temperature dependent shift of the switchover point relative to the internal sensor voltage occurs and regulation can be effected with the regulating apparatus in a temperature in dependent manner to a desired point in the sensor voltage curve or to a desired lambda value.

Drews, U.; Mohrle, W.; Werner, P.

1982-08-24

229

Studies on the mixing of liquid jets and pre-atomized sprays in confined swirling air flows for lean direct injection combustion  

Microsoft Academic Search

A lean direct injection (LDI) combustion concept was introduced recently to obtain both low NOsbx emissions and high performance for advanced aircraft gas turbine engines. It was reported that pollutant emissions, especially NOsbx, in a lean combustion mode depend significantly on the degree of mixing (mixedness) of supplied air and liquid fuel droplets. From a viewpoint of environmental protection, therefore,

Jun-Young Huh

1998-01-01

230

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

SciTech Connect

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

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

1996-08-01

231

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

SciTech Connect

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.

Gordon, S.

1982-07-01

232

Gas phase chemistry in catalytic combustion of methane\\/air mixtures over platinum at pressures of 1 to 16 bar  

Microsoft Academic Search

The gas-phase combustion of fuel-lean methane\\/air premixtures over platinum was investigated experimentally and numerically in a laminar channel-flow catalytic reactor at pressures 1 bar?p?16 bar. In situ, spatially resolved one-dimensional Raman and planar laser induced fluorescence (LIF) measurements over the catalyst boundary layer were used to assess the concentrations of major species and of the OH radical, respectively. Comparisons between measured and

Michael Reinke; John Mantzaras; Rolf Bombach; Sabine Schenker; Andreas Inauen

2005-01-01

233

Method of reconstruction of the chemical composition and combustion efficiency of hydrogen-air mixtures from incomplete experimental data  

Microsoft Academic Search

A principal possibility of approximate reconstruction of the chemical composition in combustion of a hydrogen-air mixture\\u000a at the end of the scramjet duct from incomplete experimental data (measured concentration of OH radicals and temperature)\\u000a under the assumption of detailed chemical equilibrium of exchange reactions is analyzed. A closed algebraic system of equations\\u000a including the concentration of OH radicals and the

M. E. Topchiyan

2008-01-01

234

Effect of outside combustion air on gas furnace efficiency. Final report 18 Sep 80-15 Oct 81  

SciTech Connect

Retrofit enclosure of gas furnaces to supply outside combustion and dilution air may save up to 6 percent of natural gas usage in cold climates. The cost effectiveness of this retrofit should be calculated for each opportunity as installed costs will vary widely depending on local building codes and furnace location. A freezing hazard exists for water heaters and lines which might be encloseded with furnace.

Brisbane, T.E.; Hancock, K.L.

1981-10-15

235

Stratified-combustion type internal combustion engine with pre-combustion-chamber  

Microsoft Academic Search

A stratified-combustion type internal combustion engine has a rich fuel-air mixture passage and an air passage both open into the main combustion chamber. A pre-combustion chamber is located adjacent to the main combustion chamber and has a connecting port to the main combustion chamber adjacent to the opening of the rich fuel-air mixture passage. The rich fuel-air mixture is supplied

Goto

1976-01-01

236

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

SciTech Connect

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

Debra F. Pflughoeft-Hassett

2003-07-01

237

Combustion heater  

Microsoft Academic Search

A wood burning combustion heater comprises a combustion chamber for long logs arranged to burn down from one end to the other in cigar-like fashion, an after-burner tube arrayed above and essentially parallel to the elongated logs with the air and burned gasses following an S-shaped path through the combustion chamber and out through the exhaust tube, an after-burner within

Kalenian

1980-01-01

238

Inhalation Health Risk Assessment of Air Toxic Emissions from Large Combustion Turbine Power Projects  

Microsoft Academic Search

Power generation from combustion turbine projects continues to grow throughout the world. With natural gas as the most common primary fuel, and low-sulfur #2 oil as the backup fuel, combustion turbines are among the cleanest forms of fossil power generation. The combination of clean fuels and high thermal efficiency results in low emissions per megawatt of electrical power generated by

Joseph J. Macak; Brian E. Greidanus; Joseph Torosian

239

Importance of clean biomass combustion for the air quality in residential areas  

Microsoft Academic Search

Wood as renewable and worldwide available fuel is used for residential heating. This wood combustion can cause very high emissions of inhalable particles resulting in short and long-term health effects. The target of this study was to justify the importance of using clean biomass combustion technologies for controlling wood smoke emissions. Emission samples were collected from a manually fed wood

Johannes Brodbeck; Michael Struschka; Guenter Baumbach; Bertram Kuch; G. Scheffknecht

2009-01-01

240

Numerical and experimental investigation of matrix-stabilized methane\\/air combustion in porous inert media  

Microsoft Academic Search

Porous media combustion offers exceptional advantages compared with techniques involving free flame burners. Porous medium burners are characterized by higher burning rates, increased flame stability, and lower combustion zone temperatures, which lead to a reduction in NOx formation. In addition, they show a very high turndown ratio, low emissions of CO, and are of very small size. In order to

G. BRENNER; K. PICKENACKER; O. PICKENACKER; D. TRIMIS; K. WAWRZINEK; T. WEBER

2000-01-01

241

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

SciTech Connect

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

Zauderer, B.

1997-04-14

242

Cavity ringdown measurements of OH radicals in microwave induced argon plasma assisted combustion of methane/air mixtures  

NASA Astrophysics Data System (ADS)

In order to study the mechanism of plasma assisted combustion, we have developed a system that injects a nonthermal low temperature atmospheric argon plasma into the burning flame of lean methane/air mixtures. The experimental results demonstrated the flammability enhancement of plasma assisted combustion in the lean flame of a fuel equivalence ratio as low as 0.2. In the argon plasma assisted combustion flame, we observed three different zones which were pure argon plasma zone, plasma-flame interacting zone, and pure flame zone. Optical emission studies showed distinct spectroscopic fingerprints of each zone. The emission intensities of OH radicals increased dramatically moving from pure plasma zone to plasma-flame interacting zone, and dropped severely from plasma-flame interacting zone to pure flame zone. In addition to the optical emission spectroscopy study, cavity ringdown spectroscopy (CRDS) was also applied in the measurements of absolute ground state OH radical number densities in the plasma assisted combustion flame. Results showed that the ground state OH radical number densities in the pure flame zone are on the order of 10^15 molecule/cm^3, and increasing within the range of first few millimeters from the combustor nozzle.

Wu, Wei; Wang, Chuji

2012-10-01

243

Vaporized liquid fuel combustion apparatus  

Microsoft Academic Search

This patent describes a vaporized liquid fuel combustion apparatus comprising: a cylinder defining a combustion chamber, the cylinder having an inlet end for receipt of combustion air, a first flange surrounding the inlet end and an outlet end for exhausting gaseous combustion products; means for introducing the fuel into the combustion chamber and ignition means exposed to the combustion chamber

Y. Kimijima; K. Kikuchi

1986-01-01

244

Ignition and Combustion of Single Boron Particles in Air at Ambient Pressure.  

National Technical Information Service (NTIS)

Experimental and theoretical studies are reported which provide basic information concerning the ignition and combustion processes of amorphous, crystalline, gamma-irradiated, and LiF coated single boron particles. All studies were conducted at ambient pr...

L. A. Cotugno W. H. McLain

1971-01-01

245

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

Federal Register 2010, 2011, 2012, 2013

...reciprocating internal combustion engines (RICE) and the standards of performance...several subcategories of existing stationary RICE on March 3, 2010, (75 FR 9648) and...reconsideration and judicial review of the 2010 RICE NESHAP rulemakings. The EPA...

2013-09-05

246

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

Federal Register 2010, 2011, 2012, 2013

...reciprocating internal combustion engines (RICE) (75 FR 9648). The final NESHAP for stationary RICE were promulgated under 40 CFR part 63, subpart...contained standards applicable to new stationary RICE and some existing stationary RICE. The...

2010-12-07

247

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

Federal Register 2010, 2011, 2012, 2013

...reciprocating internal combustion engines (RICE), as well as other regulations. The...comment period recommending that the RICE NESHAP be amended such that for any existing compression ignition (CI) RICE on offshore drilling vessels on the...

2012-10-03

248

An empirical investigation of air pollution from fossil fuel combustion and its impact on health in India during 1973–1974 to 1996–1997  

Microsoft Academic Search

Many air pollution studies examine impacts on global climate warming in the future, but impacts on health of population are more actual and concrete. The aim of this paper is to evaluate air pollution (CO2, SO2, and NOx) from fossil fuel combustion in India. Input–Output Structural Decomposition Analysis approach is used to find out their sources of changes. We also

Kakali Mukhopadhyay; Osmo Forssell

2005-01-01

249

Liquid fuel combustion apparatus  

Microsoft Academic Search

A liquid fuel combustion apparatus is described comprising: wall means defining a cylindrical combustion chamber; a cylindrical portion of the wall means having a first port therein for receiving an ignition device and a first nipple integral with the wall means and surrounding the first port; means for introducing fuel and combustion air into the combustion chamber and for removing

K. Sawada; K. Kikuchi

1987-01-01

250

Thermal Pulse Combustion  

Microsoft Academic Search

This paper describes theoretical and experimental observations of combustion oscillations produced in a continuously mixed, jet-stirred combustion system. This work is distinct from other investigations of pulse combustion, because it is shown both theoretically and experimentally that combustion oscillations can be produced with a steady supply of fuel and air, requiring no mechanical or aerodynamic valves. The theory is a

G. A. RICHARDS; G. J. MORRIS; D. W. SHAW; S. A. KEELEY; M. J. WELTER

1993-01-01

251

Rotary internal combustion engine  

SciTech Connect

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.

Le, L.K.

1990-11-20

252

Fuel combustion system and method of operation for an Otto-cycle internal combustion engine  

Microsoft Academic Search

This paper describes a method of combusting a predetermined combustible mixture of fuel and air in an Otto-cycle internal combustion engine including a main combustion chamber, first control valve means for admitting the combustible mixture into the main combustion chamber, an auxiliary combustion chamber, second control valve means for opening and blocking fluid communication between the main combustion chamber and

Bailey

1991-01-01

253

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

Microsoft Academic Search

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

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

2009-01-01

254

Turbulent Diffusion Combustion Model Using Chemical Equilibrium Combined with the Eddy Dissipation Concept for Reducing Detailed Chemical Mechanisms : An Application of H2-air Turbulent Diffusion Flame  

Microsoft Academic Search

This research aims at building a turbulent diffusion combustion model based on chemical equilibrium and kinetics for simplifying complex chemical mechanism. 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 H2-air turbulent diffusion flame. In the CE-EDC model, the reaction rate of fuels and

Kazui Fukumoto; Yoshifumi Ogami

2010-01-01

255

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

Microsoft Academic Search

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

Kazui Fukumoto; Yoshifumi Ogami

2010-01-01

256

Numerical Investigation on the Effects of Inlet Air Temperature on Spray Combustion in a Wall Jet Can Combustor Using the k-? Turbulence Model  

Microsoft Academic Search

A three-dimensional numerical study was performed to assess the effects of inlet temperature and equivalence ratio on the spray combustion and subsequent NOx emission in a wall jet can combustor (WJCC) installed with twin-fluid air-assisted fuel atomizers. The RNG k ? ? turbulence model, eddy breakup (EBU) combustion model, and the Zeldovich model of NOx formation were utilized in the numerical study.

Sangpil Jo; Ho Young Kim; Sam S. Yoon

2008-01-01

257

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

PubMed

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

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

2008-12-10

258

Numerical simulation of air and oxy-fuel combustion of single coal particles using the reactive implicit continuous-fluid Eulerian (RICE) method  

NASA Astrophysics Data System (ADS)

The paper presents the mathematical model of air and oxy-fuel combustion of single coal particles. The combustion process has been treated as a spherically-symmetric one. The 1-dimensional time-dependent conservation equations governing the process have been numerically solved using the RICE method. The presence of a coal particle, which was treated as a discrete Lagrange particle, has modified the boundary conditions at the gas-solid interface. Numerical results show good agreement with the experimental results.

Lewtak, Robert

2013-10-01

259

Development of the utilization of combustible gas produced in existing sanitary landfills: Investigation of effects of air inclusion  

NASA Astrophysics Data System (ADS)

The effects of nitrogen and oxygen on landfill gas operations are discussed. A combustible gas mixture composed of methane and carbon dioxide is generated in municipal solid waste landfills. A consequence of the collection of this fuel gas is the inclusion of some air in the collected product. The effects include increased collected 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 by using landfill data of a gas recovery site as a basis. Useful supplemental fuel gas may be recovered despite the inclusion of air. Recommendations are made for establishing limits for nitrogen and oxygen content and minimizing the costs associated with their presence.

1983-01-01

260

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

SciTech Connect

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.

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

2005-06-30

261

Effects of addition of electrolysis products on methane\\/air premixed laminar combustion  

Microsoft Academic Search

In this study, effects of the addition of small amounts of water electrolysis products on laminar premixed methane\\/air flames have been investigated using chemical kinetic simulation methods. The CHEMKIN kinetic simulation package was used with the GRI kinetic mechanism. Pollutant concentrations, flame speeds, temperature profiles and lean flammability limits of methane\\/air, methane\\/hydrogen\\/air and methane\\/hydrogen\\/oxygen\\/air systems were compared at different addition

C. Uykur; P. F. Henshaw; D. S.-K. Ting; R. M. Barron

2001-01-01

262

Time dependent flame propagation through premixed and liquid fuel-air combustible mixtures  

Microsoft Academic Search

Unsteady one dimensional combustion of fuel vapor, premixed gas and monodisperse spray in a stagnant, oxidizing environment were investigated using one step second order reaction kinetics. The governing equations were simplified and solved numerically for each specific problem. Two different approaches were used to formulate the liquid phase equations. The first method treated the liquid phase as continuous media. A

Vural

1982-01-01

263

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

National Technical Information Service (NTIS)

Calcium oxide sorbents injected in a slagging combustor react with the sulfur released during coal combustion to form sulfur bearing particles, some of which are deposited on the liquid slag layer on the combustor wall. Since the solubility of sulfur in l...

B. Zauderer

1997-01-01

264

186 Improving Robustness of Spray Guided DI Combustion Systems: The Air-Assisted Approach  

Microsoft Academic Search

Although the direct injection gasoline engine offers the potential for large fuel consumption reductions in passenger vehicles, the wide spread adoption of this technology has been slow. With the onset of ever increasingly stringent emissions legislation requiring the reduction of exhaust pollutants, the DI combustion system for the future must therefore exhibit the favourable combination of significant fuel consumption reduction

Geoffrey CATHCART

265

Effect of excess air on grate combustion of solid wastes and on gaseous products  

Microsoft Academic Search

An experimental study has been conducted in a fixed bed reactor to simulate, in a laboratory scale, industrial municipal waste incineration using moving grates. Carbon monoxide, nitrogen oxide, temperatures and mass loss rate measurements have been used to establish the importance of the operating parameters of a municipal waste incinerator in the characteristics of the combustion process. The present work

Thomas Rogaume; F. Jabouille; J. L. Torero

2009-01-01

266

Device for controlling primary and secondary air\\/fuel ratios for internal combustion engine  

Microsoft Academic Search

An internal combustion engine has an exhaust manifold, an inlet manifold, and a carburetor which has a fuel jet. An oxygen sensor is mounted within the exhaust manifold, and produces an output signal according to the oxygen present within the exhaust gases. A computing means computes a corrective signal according to the oxygen sensor output signal. This corrective signal is

M. Horikoshi; T. Onishi; M. Sato

1983-01-01

267

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...

268

Emission spectroscopy of hot water vapor from H 2–air deflagrative combustion in a closed cylinder  

Microsoft Academic Search

The water molecule is often selected as a probe of its environment to retrieve distributions of temperature and concentration in a hot gas by emission spectroscopy. A combustion chamber closed at both ends has been designed and a fast CCD camera coupled to an Ebert–Fastie spectrometer was used to experimentally validate the current spectroscopic parameters of H2O at high pressures

P. Chelin; C. Camy-Peyret; V. Pina; P. Alkhoury; D. Davidenko

2005-01-01

269

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

SciTech Connect

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.

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

270

76 FR 12863 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...  

Federal Register 2010, 2011, 2012, 2013

...Reciprocating Internal Combustion Engines (RICE). EPA has subsequently determined, following...will serve as the proposal to amend the RICE NESHAP if significant adverse comments...I own or operate an existing stationary RICE located at an area source of HAP...

2011-03-09

271

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

SciTech Connect

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.

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

1993-10-26

272

Ignition of combustible/air mixtures by small radiatively heated surfaces.  

PubMed

Optical radiation as an ignition source in potentially explosive atmospheres was investigated for a number of explosive mixtures with respect to the most important case occurring in practice, i.e., absorption of the radiation by a solid target. Iron oxide was used as the target material. The combustibles were selected in compliance with the well-known temperature classes and apparatus groups to allow a useful graduation of the power limits to be applied. PMID:10648944

Welzel, M M; Schenk, S; Hau, M; Cammenga, H K; Bothe, H

2000-02-01

273

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

Microsoft Academic Search

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

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

1991-01-01

274

Combustion of slugs of propane and air moving up through an incipiently fluidized bed  

Microsoft Academic Search

A mathematical model is proposed to show the evolution of temperature, chemical composition and energy release or transfer in slugs, clouds and particulate phase, in a fluidized bed where there are slugs, of a mixture of air and propane, moving up through the particulate phase previously set in the state of incipient fluidization with air. The analysis begins as the

L. Ribeiro; C. Pinho

2007-01-01

275

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

National Technical Information Service (NTIS)

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 concer...

J. D. Wesnor

1993-01-01

276

Fluidized bed combustion method  

SciTech Connect

A process is described for fluidized bed combustion of particulate combustible material in a furnace comprising feeding the particulate combustible material to the furnace and imparting a turbulent fluidized bed motion to the particulate combustible material within the furnace through the use of a vibrating screen. The screen is connected to means for vibrating the screen as the principal source of energy for imparting the turbulent fluidizing motion to the combustible material. This feeds combustion air to the fluidized bed of combustible material, discharging products of combustion from the furnace, and causing the fluidized bed to move in substantially horizontal direction so that combustible material is conveyed from the location of feed to the furnace through a combustion stage in the furnace to the location of discharge as combustible products.

Love, R.E.

1986-12-16

277

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

PubMed Central

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

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

2012-01-01

278

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

SciTech Connect

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

Richardson, E.S.; Grout, R.W.; Chen, J.H. [Reacting Flow Research Department, Combustion Research Facility, Sandia National Laboratories, P.O. Box 969 MS 9051, Livermore, CA 94551-0969 (United States); Sankaran, R. [National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6008 (United States)

2010-03-15

279

Experimental investigation of pressure and blockage effects on combustion limits in H{sub 2}-air-steam mixtures  

SciTech Connect

Experiments with hydrogen-air-steam mixtures, such as those found within a containment system following a reactor accident, were conducted in the Heated Detonation Tube (43 cm diameter and 12 m long) to determine the region of benign combustion; i.e., the region between the flammability limits and the deflagration-to-detonation transition limits. Obstacles were used to accelerate the flame; these include 30% blockage ratio annular rings, and alternate rings and disks of 60% blockage ratio. The initial conditions were 110 {degree}C and one or three atmospheres pressure. A benign burning region exists for rich mixtures, but is generally smaller than for lean mixtures. Effects of the different obstacles and of the different pressures are discussed.

Sherman, M.P.; Berman, M. [Sandia National Labs., Albuquerque, NM (United States); Beyer, R.F. [Westinghouse Electric Corp., Pittsburgh, PA (US)

1993-06-01

280

Spray Combustion and Emissions in a Direct- Injection Two Stroke Engine with Wall-Stabilization of an Air-Assisted Spray.  

National Technical Information Service (NTIS)

Previous experiments using an air-assisted spray in a impinge two-stroke direct-injected engine demonstrated a significant improvement in combustion stability at part-load conditions when a wide injection spray was used. It was hypothesized caused that th...

M. V. Casarella M. L. Syvertsen J. K. Martin J. A. Hoffman J. B. Ghandhi

1997-01-01

281

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

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

282

SET UP AND OPERATION OF A RECIRCULATING WETTED RIGID MEDIA EVAPORATIVE COOLER INSTALLED IN A GAS TURBINE COMBUSTION INLET AIR SYSTEM  

Microsoft Academic Search

A procedure for setting up and operating a recirculating evaporative cooler installed in the combustion air inlet system of a gas turbine is described. The procedure includes a recommendation for selecting the ambient operating wet and dry bulb temperatures. A description of the parameters used in the procedure and calculation methods are shown. In response to frequent inquiries about the

R. S. Johnson

283

Feed forward combustion control system  

Microsoft Academic Search

A feed forward control system maximizes combustion efficiency in a combustion system, by controlling the amount of excess air supplied to the burner. The feed forward control system includes flow sensors for sensing the flow of air and fuel to the burner. Based upon the fuel flow measurement, a digital computer determines the correct stoichiometric amount of combustion air required

R. C. Hanson; L. C. Hanson

1985-01-01

284

Controlling Combustion-Source Emissions at Air Force Sites. Phase 2.  

National Technical Information Service (NTIS)

This report describes the development and demonstration of several new technologies for controlling air pollutants, particularly nitrogen oxides (NOX) and small particulates. It provides the results of a project undertaken to investigate potential NOx pro...

S. G. Nelson R. A. Babyak B. C. Cianciolo

1997-01-01

285

Mapping the time-averaged distribution of combustion-derived air pollutants in the San Francisco Bay Area  

NASA Astrophysics Data System (ADS)

Urban air pollution is an ongoing and complicated problem for both residents and policy makers. This study aims to provide a better understanding of the geographic source and fate of organic pollutants in a dynamic urban environment. Natural and artificial hydrophobic substrates were employed for the passive monitoring and mapping of ground-level organic pollutants in the San Francisco Bay area. We focused specifically on volatile and semi-volatile polycyclic aromatic hydrocarbons (PAHs). These compounds are proxies for a broad range of combustion related air pollutants derived from local, regional, and global combustion sources. PAHs include several well-studied carcinogens and can be measured easily and accurately across a broad range of concentrations. Estimates of time-integrated vapor phase and particle deposition were made from measuring accumulated PAHs in the leaves of several widely distributed tree species (including the Quercus agrifolia and Sequoia sempervirens) and an artificial wax film. Samples were designed to represent pollutant exposure over a period of one to several months. The selective sampling and analysis of hydrophobic substrates providess insight into the average geographic distribution of ground-level air pollutants in a simple and inexpensive way. However, accumulated organics do not directly correlated with human exposure and the source signature of PAHs may be obscured by transport, deposition, and flux processes. We attempted to address some of these complications by studying 1) PAH accumulation rates within substrates in a controlled microcosm, 2) differences in PAH abundance in different substrate types at the same locality, and 3) samples near long-term high volume air sampling stations. We also set out to create a map of PAH concentrations based on our measurements. This map can be directly compared with interpolated data from high-volume sampling stations and used to address questions concerning atmospheric heterogeneity of these pollutants (i.e. due to both source localization and dominant wind patterns). Our initial results indicate that exposure to PAHs in the bay area is geographically heterogeneous and individual exposure may vary by more than two orders of magnitude. The signatures of PAH contamination also varies considerably, indicating different sources and differing transportation mechanisms may be important at different sites and times.

Yu, C.; Zinniker, D. A.; Moldowan, J.

2010-12-01

286

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

SciTech Connect

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.

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

2003-04-24

287

Experimental study of humid air reverse diffusion combustion in a turbulent flow field  

Microsoft Academic Search

Experiments were performed to investigate the differences between the propane\\/air turbulent diffusion reactive flows past\\u000a bluff-body and the propane\\/humid air turbulent diffusion reactive flows in the same conditions. The velocity distributions\\u000a of the non-humid reactive flow fields and the humid reactive flow fields were measured by particle image velocimetry (PIV)\\u000a techniques. The temperature fields were measured by high temperature thermocouples,

Bing Ge; Shusheng Zang; Xin Gu

2007-01-01

288

Numerical study of the effect of hydrogen addition on methane–air mixtures combustion  

Microsoft Academic Search

The stoichiometric methane–hydrogen–air freely propagated laminar premixed flames at normal temperature and pressure were calculated by using PREMIX code of CHEMKIN II program with GRI-Mech 3.0 mechanism. The mole fraction profiles and the rate of production of the dominant reactions contributing to the major species and some selected intermediate species in the flames of methane–hydrogen–air were obtained. The rate of

Jinhua Wang; Zuohua Huang; Chenglong Tang; Haiyan Miao; Xibin Wang

2009-01-01

289

A numerical study of hydrogen-air combustion within a supersonic boundary layer  

SciTech Connect

A numerical study of the ignition and spread of combustion within a supersonic boundary layer is presented for case where ignition is triggered by viscous dissipation and/or wall temperature effects. Three important regions are found in the boundary layer in the streamwise direction. They are: (1) an induction region where the process is mainly controlled by streamwise convection and chemical kinetics in the presence of transverse molecular transports, (2) a thermal runaway region corresponding to a large chemical heat release, (3) a flame region which develops at the end of the thermal runaway region where a flame is stabilized at the outer edge of the boundary layer. The whole chemical process becomes endothermic for large values of free-stream Mach numbers due to intense dissociation effects. 11 refs.

Figueira da silva, L.F.; Deshaies, B.; Champion, M. (Ecole Nationale Superieure de Mecanique et d'Aerotechnique, Poitiers, (France))

1992-01-01

290

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

SciTech Connect

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.

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

1989-01-01

291

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

SciTech Connect

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.

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

292

Internal combustion engine and method  

SciTech Connect

This patent describes a method of increasing performance and eliminating detonation in an internal combustion engine. It comprises: combusting, in a combustion cylinder having a piston connected by a crank arm to a crank shaft, cooled compressed air mixed with fuel to form a combustible fuel mixture having a temperature below its autoignition temperature before combustion, the air/fuel mixture being sufficiently cool to prevent detonation of the mixture ahead of the flame front during combustion, introducing the fuel into the combustion chamber at a timed rate during the combustion whereby at least a portion of the combustion has an elapsed time of combustion at substantially constant pressure over a minimum crank angle duration of 45{degrees} after top dead center, and exhausting products of combustion from the combustion cylinder.

Haring, J.M.

1992-04-14

293

Combustion chamber noise suppressor  

Microsoft Academic Search

A combustion chamber is described for a hot fog generating machine comprising a hollow cylindrical combustion chamber shell having a closure plate at one end and outlet means at the opposite end for directing hot combustion gasses to a fogging nozzle, air inlet means disposed adjacent the outlet means, fuel inlet means and ignition means mounted in the closure plate

1986-01-01

294

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 ...

295

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

Microsoft Academic Search

This study used the seventeen monitor air quality network in the Chestnut Ridge region of Pennsylvania to evaluate the effect of pollutant trends and representations on measures of exposure. Data consisted of four and five years of SOâ and TSP measurements, respectively, and were considered in deriving exposure models. A cross-sectional study of 4071 children aged 6 to 11 years

S. Batterman; D. Golomb

1985-01-01

296

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

EPA Science Inventory

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

297

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

NASA Astrophysics Data System (ADS)

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 equations, the solver finds iteratively the mixture pressure and temperature; in addition it furnishes a complete description of chemical and physical transformations. 2D numerical simulations give encouraging agreement with experimental pressure histories recorded on the chamber wall. It is shown that multiple blast wave reflections from the walls of the chamber strongly accelerate particle burning. The results demonstrate the advantages of the equilibrium EOS model and appeal for 3D AMR calculations on massively-parallel computers, which should better define the initial stage of turbulent particle dissemination.

Khasainov, Boris; Kuhl, Allen; Victorov, Sergey; Neuwald, Peter

2005-07-01

298

Air extraction and LBTU coal gas combustion in gas turbines for IGCC systems  

SciTech Connect

The primary objective of the cold flow experiments is to study the effects of air extraction from two sites in a heavy-frame gas turbine: (1) the engine wrapper or manholes and (2) the compressor/combustor prediffuser inlet. The experiments involve a scale model of components of a state-of-the-art, US made gas turbine between the compressor exit and the turbine inlet Specifically, the purpose is to observe and measure how air extraction affects the flow distribution around the combustor cans and the impingement cooling flow rates on transition pieces of the combustor. The experimental data should provide turbine manufacturers the information needed to determine their preferred air extraction site. The secondary objectives for the experiments are as follows: (1) to identify regions with high-pressure losses, (2) to develop a dam base which will validate computational fluid dynamic calculations, and (3) to establish an experimental facility which may be used to assist the US industry in improving the aerodynamic design of nonrotating components of a heavy-frame gas turbine.

Yang, Tah-teh; Agrawal, A.K.; Kapat, J.S.

1992-01-01

299

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

PubMed

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

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

2013-01-16

300

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

PubMed

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

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

2013-01-30

301

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

PubMed

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

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

2006-08-01

302

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

SciTech Connect

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 land-fill 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/m{sup 2}hr), whereas FGD material mixed with fly ash and pyrite exhibited higher emission rates ({approximately} 10 ng/m{sup 2}hr) but were still comparable with natural background soils (- 0.3 to 13 ng/m{sup 2}hr). 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. 19 refs., 4 figs., 6 tabs.

Mei Xin; Mae S. Gustin; Kenneth Ladwig; Debra F. Pflughoeft-Hassett [University of Nevada, Reno, NV (United States). Department of Natural Resources and Environmental Science

2006-08-15

303

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)

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.

Fukumoto, Kazui; Ogami, Yoshifumi

304

Do oxygen-enriched atmospheres exist beneath surgical drapes and contribute to fire hazard potential in the operating room?  

PubMed

The purposes of this study were to (1) describe the microenvironment in terms of oxygen concentration beneath the drapes of healthy subjects who were simulating patients undergoing minor surgical procedures with supplemental oxygen and to (2) evaluate the efficacy of using a scavenger system beneath the drapes. A convenience sample of 12 healthy volunteer subjects was studied in an ambulatory surgery center operating room, which was ventilated with 25 air exchanges per hour. The study was carried out in 2 parts. Each subject was supine, and oxygen was applied by a standard nondivided nasal cannula. The subjects were draped as routinely done for ophthalmic procedures. Oxygen concentrations were measured by using an Ohmeda Rascal II gas analyzer beneath the drapes and at the hypothetical surgical site with oxygen flow rates of 0, 1, 2, 3, and 4 L/min, allowing 5 minutes to elapse after a change in flow rate was made. Following a 10-minute break, the subjects were redraped, and the procedure was repeated using a scavenger system consisting of a suctioning system connected to wall suction at 170 to 190 mm Hg. Although the mean +/- SD oxygen saturation never fell below 95% (97.75% +/- 1.54%), mean +/- SD oxygen concentrations beneath the drapes were lower than normal room air concentrations (19.08% +/- 0.51%) when no oxygen was delivered to the patient. With supplemental oxygen and no scavenger system, oxygen concentrations beneath the drapes were consistently elevated (as high as 45% with 4 L/min) compared with normal ambient concentrations (21%) or with concentrations obtained at the surgical site (as high as 23.4%). With the scavenger system in place, mean +/- SD oxygen concentrations reached 34.08% +/- 5.52% beneath the drapes. Statistical analyses revealed that significantly higher oxygen concentrations occurred beneath the drapes with each incremental change in oxygen flow rate, and regardless of the oxygen flow rate used, oxygen concentrations beneath the drapes were significantly reduced with the use of the scavenger system. PMID:10876463

Barnes, A M; Frantz, R A

2000-04-01

305

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

Microsoft Academic Search

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

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

1995-01-01

306

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

Microsoft Academic Search

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

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

1995-01-01

307

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

Microsoft Academic Search

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

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

1995-01-01

308

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

Microsoft Academic Search

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

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

1995-01-01

309

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

Microsoft Academic Search

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

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

1995-01-01

310

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

Microsoft Academic Search

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

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

1995-01-01

311

Effect of the Vane Angle for Outer Secondary Air on the Flow and Combustion Characteristics and NOx Emissions of the Low-NOx Axial-Swirl Coal Burner  

Microsoft Academic Search

We conducted a cold air experiment and numerical simulation to investigate flow and combustion characteristics and NOx emission of a low-NOx axial-swirl burner in a 600 MWe bituminous coal-burning boiler. Comparison of single-phase numerical simulation results and measurements made by a probe with hot-film sensors shows that the numerical model is a reasonable description. By changing the vane angle for outer

Lingyan Zeng; Zhengqi Li; Guangbo Zhao; Shanping Shen; Fucheng Zhang

2011-01-01

312

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

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)

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

313

Combustion characteristics of high ash coal in a pulverized coal combustion  

Microsoft Academic Search

The influences of ash content on pulverized coal combustion characteristics are experimentally and numerically studied under a staged combustion condition. The stage combustion ratio (the ratio of air volume of the staged combustion air to the total air) is 0 or 30%, and the coals tested are the three high ash coals with different ash contents of 36, 44 and

R. Kurose; M. Ikeda; H. Makino

2001-01-01

314

Comparison of pulverized coal combustion in air and in O 2\\/CO 2 mixtures by thermo-gravimetric analysis  

Microsoft Academic Search

Thermo-gravimetric technique was used to study the combustion characteristics of pulverized coal in different O2\\/CO2 environments. The effects of combustion environment, oxygen concentration, particle size and heating rate were considered and the differences of pulverized coal pyrolysis, combustion and gaseous compounds release under two environments were analyzed. Results show that the coal pyrolysis in CO2 environment can be divided into

Qingzhao Li; Changsui Zhao; Xiaoping Chen; Weifang Wu; Yingjie Li

2009-01-01

315

Air pollution from household solid fuel combustion in India: an overview of exposure and health related information to inform health research priorities  

PubMed Central

Environmental and occupational risk factors contribute to nearly 40% of the national burden of disease in India, with air pollution in the indoor and outdoor environment ranking amongst leading risk factors. It is now recognized that the health burden from air pollution exposures that primarily occur in the rural indoors, from pollutants released during the incomplete combustion of solid fuels in households, may rival or even exceed the burden attributable to urban outdoor exposures. Few environmental epidemiological efforts have been devoted to this setting, however. We provide an overview of important available information on exposures and health effects related to household solid fuel use in India, with a view to inform health research priorities for household air pollution and facilitate being able to address air pollution within an integrated rural–urban framework in the future.

Balakrishnan, Kalpana; Ramaswamy, Padmavathi; Sambandam, Sankar; Thangavel, Gurusamy; Ghosh, Santu; Johnson, Priscilla; Mukhopadhyay, Krishnendu; Venugopal, Vidhya; Thanasekaraan, Vijayalakshmi

2011-01-01

316

Characterization of air emissions from the simulated open combustion of fiberglass materials. Final report, January 1992-August 1993  

SciTech Connect

The exposure of persons to fiberglass combustion emissions from structural fires, fires at waste landfills, and fires at demolition sites has become an issue of increasing concern. The study 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 the boating and building materials industries) were combusted in a controlled outbuilding designed to simulate open burning. Volatile, semivolatile, and particulate-bound organics were collected and analyzed by gas chromatography/mass spectrometry (GC/MS).

Lutes, C.C.; Ryan, J.V.

1993-12-01

317

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

PubMed Central

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

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

2012-01-01

318

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...

319

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

PubMed Central

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

Topaz, Moris

2012-01-01

320

Air  

MedlinePLUS

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

321

Combustion process for reducing nitrogen oxides  

Microsoft Academic Search

A combustion process, for reducing nitrogen oxides in combustors, is proposed wherein combustion takes place successively forming an incomplete combustion zone, a reducing combustion zone, and a complete combustion zone, respectively corresponding to primary burners, secondary burners and air ports or after-burners, successively arranged in the direction of gas stream in a furnace. According to the present invention, it is

K. Okiuya; I. Akiyama; Y. Arikawa; A. Baba; S. Morita; H. Terada

1983-01-01

322

Chemical characterization of air masses transported to the Arctic during the ARCTAS-A spring deployment: biomass burning versus fossil fuel combustion signatures  

NASA Astrophysics Data System (ADS)

A major research objective of the ARCTAS-A field campaign was to obtain in-situ data on the nature and the extent of atmospheric pollution in the Arctic during spring. We deployed a PTR-MS instrument aboard the NASA DC-8 research aircraft to measure a series of volatile organic compounds (VOCs) including acetonitrile, methanol, acetone and benzene. The VOCs serve as tracers for mid-latitude pollution of different nature (biomass burning vs. fossil fuel combustion) and age. For air mass classification, we additionally use the DACOM dataset for carbon monoxide (CO) which is a general long-lived tracer for incomplete combustion. According to our analysis, strongly biomass-burning impacted air was encountered during the second half of the campaign at altitudes between 1.8 and 7.4 km, with the maximum impact being observed at altitudes between 3.5 and 5 km. A pronounced signature of fossil fuel combustion-derived pollution was observed at altitudes mostly above 1 km including some strongly polluted layers at high altitudes between 6 and 8.5 km. Furthermore, our markers indicate the omnipresence of aged background pollution of anthropogenic origin. In our ongoing analysis, we are comparing the experimental results with the output from the FLEXPART chemical tracer transport model which will allow us to locate the geographic source regions of the observed pollution tracers.

Wisthaler, A.; Mikoviny, T.; Diskin, G. S.; Sachse, G. W.; Burkhart, J. F.

2009-12-01

323

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...

324

Method and apparatus for obtaining a control variable for the closed-loop control of the fuel-air ratio in the operating mixture of internal combustion engines  

SciTech Connect

A method and apparatus is proposed for obtaining a control variable for the closed-loop control of the fuel-air ratio of the operating mixture of internal combustion engines, in which a threshold-current sensor of known structure is used. By means of varying the measurement voltage present at the threshold-current sensor by voltage amounts which correspond to a change in oxygen concentration to be expected in association with a change in operational state, the time behavior of the threshold-current sensor, which is essentially sluggish, is compensated for and it becomes possible to use it for rapidly-functioning closed-loop control systems in internal combustion engines.

Dietz, H.; Linder, E.; Maurer, H.; Muller, K.; Reber, H.; Rieger, F.

1982-10-26

325

Effect of an External Electric Field on the Disperse Composition of Condensed Products of Aluminum Particle Combustion in Air  

Microsoft Academic Search

Investigation was performed of the effect of an external electric field on the completeness of combustion of ASD-1 aluminum powder in an airflow and on the disperse composition of condensed combustion products. It is established that for an oxidizer-to-fuel ratio of 0.8 and a combustor inlet flow rate of 10 m\\/sec, the application of an electric field increases the completeness

D. A. Yagodnikov; E. I. Gusachenko

2002-01-01

326

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

PubMed

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

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

2010-08-15

327

Continuously-variable rate pulse combustion apparatus  

Microsoft Academic Search

This patent describes continuously-variable rate pulse combustion apparatus. It comprises: a main burner; a primary burner; main fuel supply means; primary fuel supply means; main air supply means; primary air supply means; combustion chamber means; exhaust means; inlet air decoupling means; main inlet air means; primary inlet air means; and main valve means.

W. H. Thrasher; G. J. Wells

1991-01-01

328

Combustion chamber construction  

Microsoft Academic Search

A combustion chamber is described for use in gas turbine engines, the chamber comprising: an inlet for receiving air and fuel to be burned; an outlet for expelling products of combustion; high strength structural frame means disposed between the inlet and the outlet for supporting mechanical forces associated with the chamber; liner means cooperating with the frame and defining a

A. P. Sterman; T. G. Wakeman; J. J. Williams

1986-01-01

329

Internal combustion engine  

Microsoft Academic Search

An improvement to an internal combustion engine is disclosed that has a fuel system for feeding a fuel-air mixture to the combustion chambers and an electrical generation system, such as an alternator. An electrolytic cell is attached adjacent to the engine to generate hydrogen and oxygen upon the application of a voltage between the cathode and anode of the electrolytic

Valdespino

1981-01-01

330

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

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.

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

1995-10-11

331

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

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.

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

1995-10-01

332

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

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.

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

1995-10-11

333

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

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.

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

1995-10-11

334

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

SciTech Connect

A novel high-heat transfer low NO(sub x) natural gas combustion system. The objectives of this program are to research, develop, test, and commercialize a novel high-heat transfer low-NO{sub x} natural gas combustion system for oxygen-, oxygen-enriched air, and air-fired furnaces. This technology will improve the process efficiency (productivity and product quality) and the energy efficiency of high-temperature industrial furnaces by at least 20%. GTI's high-heat transfer burner has applications in high-temperature air, oxygen-enriched air, and oxygen furnaces used in the glass, metals, cement, and other industries. Development work in this program is focused on using this burner to improve the energy efficiency and productivity of glass melting furnaces that are major industrial energy consumers. The following specific project objectives are defined to provide a means of achieving the overall project objectives. (1) Identify topics to be covered, problems requiring attention, equipment to be used in the program, and test plans to be followed in Phase II and Phase III. (2) Use existing codes to develop models of gas combustion and soot nucleation and growth as well as a thermodynamic and parametric description of furnace heat transfer issues. (3) Conduct a parametric study to confirm the increase in process and energy efficiency. (4) Design and fabricate a high-heat transfer low-NOx natural gas burners for laboratory, pilot- and demonstration-scale tests. (5) Test the high-heat transfer burner in one of GTI's laboratory-scale high-temperature furnaces. (6) Design and demonstrate the high-heat transfer burner on GTI's unique pilot-scale glass tank simulator. (7) Complete one long term demonstration test of this burner technology on an Owens Corning full-scale industrial glass melting furnace. (8) Prepare an Industrial Adoption Plan. This Plan will be updated in each program Phase as additional information becomes available. The Plan will include technical and economic analyses, energy savings and waste reduction predictions, evaluation of environmental effects, and outline issues concerning manufacturing, marketing, and financing. Combustion Tec, Owens Corning, and GTI will all take active roles in defining this Plan. During Phase I, the first three objectives were addressed and completed along with the design component of the fourth objective. In Phase II, the fabrication component of the fourth objective was completed along with objectives five and six. Results of the Phase I work were reported in the Phase I Final Report and are summarized in this Final Technical Report. Work for Phase II was divided in four specific Tasks. Results of the Phase II work were reported in the Phase II Final Report and are also summarized in this Final Technical Report. No Phase III Final Report was prepared, so this Final Technical Report presents the results of Phase III commercial demonstration efforts. A description of each Task in Phases I, II, and III is presented in this report.

Abbasi, H.

2004-01-01

335

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

SciTech Connect

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

Selle, L.; Ferret, B. [Universite de Toulouse, INPT, UPS, IMFT, Institut de Mecanique des Fluides de Toulouse (France); CNRS, IMFT, Toulouse (France); Poinsot, T. [Universite de Toulouse, INPT, UPS, IMFT, Institut de Mecanique des Fluides de Toulouse (France); CNRS, IMFT, Toulouse (France); CERFACS, Toulouse (France)

2011-01-15

336

Combustion device for combustion of a gaseous fuel  

SciTech Connect

This patent describes a combustion device for a hot gas engine having tubes containing working gas. The combustion device has a gaseous fuel with air supplied at a pressure slightly above atmospheric. The device comprises a combustion chamber, a preheater for heating the combustion air by exhaust gases leaving the combustion chamber, a blower for supplying air to the preheater, means for governing the mass flow of air supplied from the blower, a plenum chamber receiving preheated air from the preheater and delivering the preheated air to the combustion chamber. The plenum chamber includes first and second swirl devices for guiding the preheated air as primary and secondary air respectively for combustion, means for delivering a mass flow of gaseous fuel to the combustion chamber as a function of the mass flow of preheated air is supplied. The fuel delivery means includes an ejector having a flow restriction and a tube supplying the gaseous fuel at a pressure slightly above atmospheric to the flow restriction. The tube has an open terminal end protruding into and terminating within the ejector at a most restricted flow area in the restriction. The swirl device is located upstream of the ejector.

Alpqvist, J.A.

1987-06-30

337

FLAMELESS COMBUSTION AND ITS APPLICATIONS  

Microsoft Academic Search

Flameless Combustion was first developed to suppress thermal NOx formation in burners for heating industrial furnaces using preheated combustion air. While this technique is applied in large numbers now, there are a number of other applications emerging. This presentation will give an introduction into flameless combustion and then show industrial applications and applications which are at a research stage. -

Joachim G. Wünning

338

Pilot-scale evaluation of the potential for emissions of hazardous air pollutants from combustion of tire-derived fuel. Final report, February 1992-October 1993  

SciTech Connect

Experiments were conducted in a 73kW (250,000 Btu/hr) rotary kiln incinerator simulator to examine and characterize emissions from incineration of scrap tire material. The purposes of this project are to: (1) generate a profile of target analytes for full-scale stack sampling efforts, not to generate statistically defensible emission factors for the controlled combustion of scrap tire material; and (2) where possible, give insight into the technical issues and fundamental phenomena related to controlled combustion of scrap tires. Along with continuous emissions monitoring for oxygen (O2), carbon dioxide (CO2), carbon monoxide (CO), nitric oxide (NO), sulfur dioxide (SO2), and total hydrocarbons (THCs), samples were taken to examine volatile and semi-volatile organics, polychlorinated p-dibenzodioxins and dibenzofurans (PCDD/PCDF), and metal aerosols. In addition, a continuous polycyclic aromatic hydrocarbon (PAH) analyzer was used in all the tests. Samples were analyzed with an emphasis on the 189 hazardous air pollutants (HAPs) listed in the 1990 Clean Air Act Amendments (CAAA), but other compounds were also identified where possible.

Lemieux, P.M.

1994-05-01

339

Combustion of Micropowdered Biomass  

NASA Astrophysics Data System (ADS)

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.

Geil, Ethan; Thorne, Robert

2009-03-01

340

Opportunities in pulse combustion  

SciTech Connect

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.

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

1985-10-01

341

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

SciTech Connect

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

Qingfeng Yu; Quanke Feng [Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049 (China)

2006-07-01

342

Combustion engine with multi-fuel capability  

Microsoft Academic Search

This patent describes a combustion engine. It has a combustion chamber, a fuel tank, a fuel delivery line from the fuel tank to the engine, air\\/fuel delivery means for pumping a mixture of one or more liquid fuels in an unknown combination from the fuel tank through the fuel delivery line to the combustion chamber in combination with air in

Gonze

1990-01-01

343

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

PubMed Central

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.

Ezzati, M; Kammen, D M

2001-01-01

344

Compressed air energy storage system  

Microsoft Academic Search

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

F. W. Ahrens; G. T. Kartsounes

1981-01-01

345

NO x -emissions from flameless coal combustion in air, Ar\\/O 2 and CO 2\\/O 2  

Microsoft Academic Search

Flameless or ‘mild’ combustion is a well known measure to reduce NOx-emissions. This work aims at the application of the technique to coal combustors. Experiments have been carried out with lignite as well as bituminous coals showing an overall NOx-reduction capability with the current burner design of about 20–50% depending on fuel type and the stoichiometry at the burner. The

Hannes Stadler; Dragisa Ristic; Malte Förster; Anja Schuster; Reinhold Kneer; Günter Scheffknecht

2009-01-01

346

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

SciTech Connect

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)

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

347

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...

348

CFD simulation of spontaneous coal combustion in irregular patterns of goaf with multiple points of leaking air  

Microsoft Academic Search

Based on the non-linear air leakage seepage equation for an anisotropic porous medium, on the seepage diffusion equation of multicomponent gas and on the seepage synthetic heat transfer equation of a porous medium, the numerical model for field flow problems of irregular patterns of a goaf with multiple points of leaking air is established and simultaneously solved by the upwind

Zong-xiang LI

2008-01-01

349

Pulse combustion space heater  

Microsoft Academic Search

This patent describes a pulse combustion space heater for heating air in a space to be temperature conditioned. It comprises: a cabinet having exterior walls providing a cabinet volume for enclosing and supporting the heater, interior housing means located within the cabinet volume including walls providing a substantially closed heat transfer chamber having inlet and outlet openings through which air

W. H. Thrasher; C. M. Pavlik; L. Moon

1990-01-01

350

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

SciTech Connect

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.

Ciccarelli, G.; Ginsberg, T.; Boccio, J.L. [and others

1997-11-01

351

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

SciTech Connect

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

Peter, C.

1980-11-04

352

Injection, atomization, ignition and combustion of liquid fuels in high-speed air streams. Annual scientific report 1 December 81-31 December 82  

SciTech Connect

A simulation approach to studying hot flow subsonic cross-stream fuel injection problems in a less complex and costly cold flow facility was developed. A typical ramjet combustion chamber fuel injection problem was posed where ambient temperature fuel (Kerosene) is injected into a hot airstream. This case was transformed through two new similarity parameters involving injection and freestream properties to a simulated case where a chilled injectant is injected into an ambient temperature airstream. Experiments for the simulated case using chilled Freon-12 injected into the Va. Tech 23 x 23 cm. blow-down wind tunnel at a freestream Mach number of 0.44 were run. The freestream stagnation pressure and temperature were held at 2.5 atm. and 300 degrees K respectively. Results showed a clear picture of the mechanisms of jet decomposition in the presence of rapid vaporization. Immediately after injection a vapor cloud was formed in the jet plume, which dissipated downstream leaving droplets on the order of 8 to 10 microns in diameter for the conditions examined. This represents a substantial reduction compared to baseline tests run at the same conditions with water which had little vaporization. The desirability of using slurry fuels for aerospace application has long been recognized, but the problems of slurry combustion have delayed their use. The present work is an experimental and numerical investigation into the break-up and droplet formation of laminar slurry jets issuing into quiescent air.

Schetz, J.A.

1983-01-01

353

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

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.

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

1995-10-11

354

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

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.

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

1995-10-11

355

Operational Tests of the Innovative Components in the Prototype Power Plant Voelklingen - Fluidized-Bed Combustion and Hot Air Gas Turbine - and Research of Their Reciprocal Influences. Final Report.  

National Technical Information Service (NTIS)

By the combination of a steam generator with the innovative components fluidized-bed combustion and hot air gas turbine in the prototype power plant Voelklingen (230 MW) for the first time a hard coal based combined cycle is realized. By the additional he...

G. Scholl L. Stadie

1987-01-01

356

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

EPA Science Inventory

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

357

Lean staged combustion assembly  

SciTech Connect

This patent describes a lean staged combustion assembly. It comprises: means for channeling compressed air including a pilot portion and a main portion. This patent also describes an annular combustor outer liner having an upstream end and a downstream end; an annular combustor inner liner having an upstream end and a downstream end and spaced from the outer liner; means for obtaining pilot stage combustion of a fuel-air pilot mixture for generating pilot stage combustion gases between the inner and outer liners using the pilot portion of compressed air channeled to the combustor by the channeling means, a pilot combustor first liner having an upstream end and a downstream end and spaced from the outer liner to define a first pilot combustion zone; a pilot combustor second liner having an upstream end and a downstream end and spaced from the inner liner to define a second pilot combustion zone; circumferentially spaced first fuel injectors and corresponding first air swirlers extending between the first and outer liners at the upstream ends thereof; and circumferentially spaced second fuel injectors and corresponding second air swirlers extending between the second and inner liners at the upstream ends thereof.

Sabla, P.E.; Dodds, W.J.; Tucker, T.M.

1992-03-31

358

Furnaces with multiple ?ameless combustion burners  

Microsoft Academic Search

In this thesis three different combustion systems, equipped with either a single or multiple ?ameless combustion burner(s), are discussed. All these setups were investigated both experimentally and numerically, i.e., using Computational Fluid Dynamics (CFD) simulations.\\u000aFlameless combustion is a combustion technology capable of accomplishing the combination of high energy ef?ciency (by preheating of the combustion air) and low emissions, especially

B. Danon

2011-01-01

359

Fuel combustion system and method of operation for an Otto-cycle internal combustion engine  

SciTech Connect

This paper describes a method of combusting a predetermined combustible mixture of fuel and air in an Otto-cycle internal combustion engine including a main combustion chamber, first control valve means for admitting the combustible mixture into the main combustion chamber, an auxiliary combustion chamber, second control valve means for opening and blocking fluid communication between the main combustion chamber and the auxiliary combustion chamber. It comprises: admitting the combustible mixture into the main combustion chamber during an intake phase of the cycle; compressing and thereby pressurizing the combustible mixture in the main combustion chamber during a compression phase of the cycle; opening the second control valve means at a predetermined time during a latter portion of the compression phase in order to admit a portion of pressurized combustible mixture into the auxiliary combustion chamber; igniting the portion of combustible mixture admitted to the auxiliary combustion chamber and thereby forming expanding burning gases; directing the expanding burning gases from the auxiliary combustion chamber into the main combustion chamber in order to penetrate and cause ignition and burning of the remaining pressurized combustible mixture in the main combustion chamber; and closing the second control valve means at a predetermined time prior to about the beginning of the next compression phase.

Bailey, J.M.

1991-11-26

360

Rotary external combustion engine  

SciTech Connect

A rotary external combustion engine wherein energy is transferred to air acting as a working gas by injection into the air of liquid water at a high temperature and pressure. The liquid water is injected either directly into the working space in the stator or into a preliminary mixing chamber. The water acts as a heat-transfer medium for heating the air. Spontaneous vaporization of the liquid water on injection increases the pressure of the air which drives the rotor before being exhausted. The exhaust water is recovered and recycled. The working space is scavenged and refilled with a fresh charge of air.

Fischer, V.H.

1984-02-21

361

Numerical study on the effect of the Over-Fire-Air to the air flow and coal combustion in a 670 t\\/h wall-fired boiler  

Microsoft Academic Search

The comparison between the numerical results of the cold air flow and the experimental data of a 670 t\\/h coal-fired boiler shows a good coincidence. The NO value of calculation is 12% less than the ones of measurement but the CO value is almost same between calculation and measurement. Mathematical models and calculation method are proved to be valid. The

Likun Huang; Zhengqi Li; Rui Sun; Jue Zhou

2006-01-01

362

Pulse combustion drying apparatus for particulate materials  

Microsoft Academic Search

This patent describes a pulse jet combustion apparatus for the drying of particulate material of the type having: a combustion chamber having an air entry end, an exhaust end and a common longitudinal axis therebetween, an air inlet conduit coaxially connected to the air entry and thereof, a primary exhaust gas conduit coaxially connected to the exhaust end thereof and,

R. R. Gray; V. M. Marguth

1987-01-01

363

Combustion leftovers  

Microsoft Academic Search

Combustion processes almost never completely exhaust all of the available fuel. In this paper, we will consider three combustion scenarios (back-to-back premixed flames in stagnation point flow, travelling combustion waves, and microgravity spherical flame balls) and show how to calculate the amount of fuel which will be left over no matter how long we allow the combustion processes to continue.

R. O Weber; G. N Mercer; H. S Sidhu

2002-01-01

364

Performance calculations for 200-1000 MWe MHD\\/steam power plants  

Microsoft Academic Search

The effects of MHD generator length, level of oxygen enrichment, and oxygen production power on the performance of MHD\\/steam power plants ranging from 200 to 1000 MW in electrical output are investigated. The plants considered use oxygen enriched combustion air preheated to 1100 F. Both plants in which the MHD generator is cooled with low temperature and pressure boiler feedwater

P. J. Staiger; G. R. Seikel

1981-01-01

365

CO{sub 2} emission abatement in IGCC power plants by semiclosed cycles: Part B -- With air-blown combustion and CO{sub 2} physical absorption  

SciTech Connect

This paper analyzes the fundamentals of IGCC power plants with carbon dioxide removal systems, by a cycle configuration alternative to the one discussed in Part A (with oxygen-blown combustion). The idea behind this proposal is to overcome the major drawbacks of the previous solution (large oxygen consumption and re-design of the gas turbine unit), by means of a semiclosed cycle using air as the oxidizer. Consequently, combustion gases are largely diluted by nitrogen and cannot be simply compressed to produce liquefied CO{sub 2} for storage or disposal. However, CO{sub 2} concentration remains high enough to make separation possible by a physical absorption process. It requires a re-pressurization of the flow subtracted from the cycle, with relevant consequences on the plant energy balance. The configuration and the thermodynamic performance of this plant concept are extensively addressed in the paper. As in the first part, the influence of the pressure ratio is discussed, but values similar to the ones adopted in commercial heavy-duty machines provide here acceptable performance. Proper attention was paid to the impact of the absorption process on the energy consumption. The resulting net overall efficiency is again in the 38--39% range, with assumptions fully comparable to the ones of Part A. Finally, the authors demonstrate that the present scheme enables the use of unmodified machines, but large additional equipment is required for exhausts treatment and CO{sub 2} separation. A final comparison between the two semiclosed cycle concepts is therefore addressed.

Chiesa, P.; Lozza, G.

1999-10-01

366

Measurement of spray combustion processes  

SciTech Connect

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

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

1984-04-01

367

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...

368

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

Microsoft Academic Search

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

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

1979-01-01

369

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

Microsoft Academic Search

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

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

1980-01-01

370

Nonane droplet combustion with and without buoyant convection: Flame structure, burning rate and extinction in air and helium  

Microsoft Academic Search

The burning and extinction characteristics of isolated small nonane droplets are examined in a buoyant convective environment and in an environment with no external axial convection (as created by doing experiments at low gravity) to promote spherical droplet flames. The ambience is air and a mixture of 30%O2\\/70%He to assess the influence of soot formation. The initial droplet diameter (Do)

J. H. Bae; C. T. Avedisian

2009-01-01

371

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

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.

Lee, R.G.M.; Green, N.J.L.; Lohmann, R.; Jones, K.C. [Lancaster Univ. (United Kingdom)

1999-09-01

372

Gas turbine combustion chamber arrangement  

Microsoft Academic Search

A gas turbine has a combustion chamber of toroidal configuration that includes separation structure dividing the combustion chamber into an annular primary zone and an annular dilution zone. Injection of compressor discharge air into the primary zone sets up a toroidal recirculation pattern of generally circular cross-sectional configuration. Fuel slinger structure at the inner periphery of the primary zone has

A. M. Heitmann; W. L. Brassert; D. N. Chouinard

1977-01-01

373

Proceedings of the 1999 international joint power generation conference (FACT-vol. 23). Volume 1: Fuels and combustion technologies; Gas turbines; and Nuclear engineering  

Microsoft Academic Search

Papers are arranged under the following topical sections: Gas turbine combustion; Advanced energy conversion; Low NOx solutions; Burner developments; Alternative fuels combustion; Advanced energy conversion technologies; Numerical modeling of combustion; Fluidized bed combustion; Coal combustion; Combustion research; Gasification systems; Mercury emissions; Highly preheated air combustion; Selective catalytic reduction; Special topics in combustion research; Gas turbines and advanced energy; and How

S. R. Jr. Penfield; N. A. Moussa

1999-01-01

374

REFERENCE GUIDELINE FOR INDUSTRIAL BOILER MANUFACTURERS TO CONTROL POLLUTION WITH COMBUSTION MODIFICATION  

EPA Science Inventory

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 adj...

375

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

Microsoft Academic Search

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)

Alessandro Effuggi; Davino Gelosa; Marco Derudi; Renato Rota

2008-01-01

376

Ignition apparatus for internal combustion engine  

Microsoft Academic Search

An ignition apparatus for an internal combustion engine comprises an intake path supplying a mixture of air and fuel into the combustion chamber of the engine, a particle supplying unit having an ejection port opening into the combustion chamber for supplying minute particles of a material which is not the fuel and has a high light absorption factor, and a

S. Mukainakano; T. Goto; T. Hattori; T. Mizuno; M. Nishida

1984-01-01

377

Compressed air energy storage system  

DOEpatents

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.

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

1981-01-01

378

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

NASA Astrophysics Data System (ADS)

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 the study. Included in this review are: the design and operating considerations involved with integrating either an atmospheric or a pressurized fluid bed combustor with a CAES system to yield practical system configurations; the integration of system configurations; the parametric performance of these system configurations; and the preliminary screening which considered performance, cost, and technical risk and led to the identification of an open-bed PFBC/CAES system as having the greatest near-term commercialization potential.

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

1980-03-01

379

Experimental Study on Preheated Air and Flue Gas Recirculation in Solid Waste Incineration  

Microsoft Academic Search

The application of high temperature air combustion in incineration of solid waste was investigated. The combustion with preheated diluted secondary combustion air had effectively more energy saving and NOX emission reduction, but required a sufficient amount of preheated secondary combustion air to save more energy than non-dilution condition. The minimum preheated secondary combustion air temperature of 15 and 17% oxygen

P. Suvarnakuta; S. Patumsawad; S. Kerdsuwan

2010-01-01

380

Lean staged combustion assembly  

Microsoft Academic Search

This patent describes a lean staged combustion assembly. It comprises: means for channeling compressed air including a pilot portion and a main portion. This patent also describes an annular combustor outer liner having an upstream end and a downstream end; an annular combustor inner liner having an upstream end and a downstream end and spaced from the outer liner; means

P. E. Sabla; W. J. Dodds; T. M. Tucker

1992-01-01

381

Combustion engineering  

SciTech Connect

This book is an introduction to combustion science. It discusses general aspects of combustion processes and deals with combustion of premixed mixtures and covers basic concepts of flame propagation, including the flame structure, burning velocity, flame stability, and the Rankine-Hugoniot equations. The book also deals with diffusive combustion, covering laminar and turbulent diffusion flames. Explosions and detonations, including ideal and nonideal explosions, and detonation wave structure are addressed. The determination of the burned gas states is discussed.

Ohtake, K.; Fujiwara, T.

1985-01-01

382

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

NASA Astrophysics Data System (ADS)

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

Yamasaki, Yudai; Iida, Norimasa

383

Mild Combustion  

Microsoft Academic Search

The Mild Combustion is characterized by both an elevated temperature of reactants and low temperature increase in the combustion process. These features are the results of several technological demands coming from different application fields. This review paper aims to collect information which could be useful in understanding the fundamentals and applications of Mild Combustion. The information in this field are

Antonio Cavaliere; Mara de Joannon

2004-01-01

384

Abstracts of Presentations for Air Force Office of Scientific Research (AFOSR) Contractors Meeting on Rocket Combustion Dynamics and Electric Combustion Phenomena (1975). Held at Lancaster, California and Edwards AFB, California on 22-25 July 1975.  

National Technical Information Service (NTIS)

This volume contains abstracts of presentations on continuing researches and technology assessments that encompasses: electric propulsion phenomena (including colloid thrusters, pulsed ablative arc discharge, and plasmas); nonsteady combustion processes i...

L. H. Caveny

1975-01-01

385

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

Microsoft Academic Search

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

2008-01-01

386

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

SciTech Connect

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.

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

1999-01-01

387

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

PubMed Central

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.

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

2013-01-01

388

Compressed air energy storage system  

Microsoft Academic Search

An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustion reciprocating engine is operated at

F. W. Ahrens; G. T. Kartsounes

2009-01-01

389

Combustion chamber noise suppressor  

SciTech Connect

A combustion chamber is described for a hot fog generating machine comprising a hollow cylindrical combustion chamber shell having a closure plate at one end and outlet means at the opposite end for directing hot combustion gasses to a fogging nozzle, air inlet means disposed adjacent the outlet means, fuel inlet means and ignition means mounted in the closure plate and liner means disposed concentrically within the cylindrical combustion chamber for controlling the flow of air and combustion gasses within the shell. The liner means includes a liner base having a frustroconical configuration with the smaller diameter end thereof disposed in communication with the outlet means and with the larger diameter end thereof disposed in spaced relation to the shell, circumferentially spaced, longitudinally extending fins extending outwardly from the liner base intermediate the liner base and the shell, a cylindrical liner midsection having circumferentially spaced fins extending outwardly therefrom between the midsection and the shell with the fins supporting the midsection on the larger diameter end of the liner base.

Livingston, A.M.

1986-08-19

390

Low NO x combustion technologies for high temperature applications  

Microsoft Academic Search

Because of the high process temperature and the high temperature to which the combustion air is preheated, NOx emissions from glass melting furnaces are extremely high. Even at these high temperatures, NOx emissions could be reduced drastically by using advanced combustion techniques such as staged combustion or flameless oxidation, as experimental work has shown. In the case of oxy-fuel combustion,

Michael Flamme

2001-01-01

391

Numerical Simulation on Forced Swirl Combustion Chamber in Diesel Engine  

Microsoft Academic Search

A concept of forced swirl combustion chamber in diesel engine is proposed in this paper. It can be used to enhance the intensity of swirl flow in the cylinder and accelerate the rate of air-fuel mixture process by designing the special structure in the combustion chamber. This new type of forced swirl combustion chamber includes double swirl combustion chamber that

Shang Yong; Liu Fu-shui; Li Xiang-rong

2011-01-01

392

Numerical Simulation on Forced Swirl Combustion Chamber in Diesel Engine  

Microsoft Academic Search

A concept of forced swirl combustion chamber in diesel engine is proposed in this paper. It can be used to enhance the intensity of swirl flow in the cylinder and accelerate the rate of air-fuel mixture process by designing the special structure in the combustion chamber. This new type of forced swirl combustion chamber includes double swirl combustion chamber that

Shang Yong; Liu Fu-shui; Li Xiang-rong

2010-01-01

393

Device for improved combustion  

SciTech Connect

A device for improved combustion is described comprising: a tubular housing member having a first end and a second end, the first and second ends each having a circular opening therethrough; a combustion chamber disposed about the second end of the-tubular-housing member; a first conduit member extending from the first end of the tubular housing member and in fluid communication with the circular opening in the first end of the tubular housing member so as to allow the passage of air therethrough; a second conduit member axially disposed within the first conduit member and extending through the first conduit member and through the tubular housing member to the circular opening the second end of the tubular housing member so as to allow the passage of fuel therethrough; means for effecting turbulence in the air passing through the tubular housing member; means for effecting turbulence in the fuel passing through the second conduit member; means for intermixing and emitting the turbulent air and the fuel in a mushroom shaped configuration with the turbulent air surrounding the mushroom shaped configuration so as to substantially eliminate noxious waste gases as by-product of combustion of the air and fuel mixture.

Polomchak, R.W.; Yacko, M.

1988-03-08

394

Combustion chamber construction  

SciTech Connect

A combustion chamber for use in gas turbine engines is provided with a liner formed of a high temperature material. The liner includes a plurality of panels of the material mounted by means of a lost motion mounting arrangement upon a high strength structural frame. As a result of this mounting arrangement, the liner is substantially isolated from structural forces associated with the combustion chamber, while the frame is substantially isolated from thermal stresses associated with the liner. For the purpose of supplying cooling air to the liner panels and frame and cooling air is passed into a plenum to cool the radially outward side of the panels. Transfer means are provided for directing the same air from the plenum to the liner inner surfaces in a cooling film. The liner mounting arrangement disclosed herein is particularly useful with difficult-to-weld liner materials (e.g., oxide dispersion strengthened materials), but its advantages commend its use with other materials also.

Maclin, H.M.

1984-11-06

395

Prediction of temperature front in a gas turbine combustion chamber  

Microsoft Academic Search

Numerical computation has been applied to investigate the temperature field in a gas turbine combustion chamber. The simulation assumed that pressure imbalance conditions of air flow between primary and secondary inlets occur. The combustion chamber under study is part of a 70MW gas turbine from an operating combined cycle power plant. The combustion was simulated with normal fuel–air flow rate

F. Z. Sierra; J. Kubiak; G. González; G. Urquiza

2005-01-01

396

Controlling Indoor Air Pollution.  

ERIC Educational Resources Information Center

|Discusses the health risks posed by indoor air pollutants, such as airborne combustion products, toxic chemicals, and radioactivity. Questions as to how indoor air might be regulated. Calls for new approaches to environmental protection. (TW)|

Nero, Anthony V, Jr.

1988-01-01

397

Computational Combustion  

SciTech Connect

Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

2004-08-26

398

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

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.

NONE

1995-12-01

399

High Pressure Combustion Test Facility for Gas Turbine Research.  

National Technical Information Service (NTIS)

A new high pressure combustion test facility was constructed in the National Aerospace Laboratory, Tokyo, to assist the national project for developing a high efficiency combined cycle gas turbine. It enables continuous combustion tests by an air mass flo...

T. Tamaru K. Shimodaira S. Horiuchi T. Saito S. Hayashi

1984-01-01

400

Study of flame quenching and near-wall combustion of lean burn fuel-air mixture in a catalytically activated spark-ignited lean burn engine  

SciTech Connect

A study of the catalytic activation of charge near the combustion chamber wall and of the flame quenching phenomenon was carried out to identify whether flame quenches due to catalytic activation or due to thermal quenching. It was found that (1) the diffusion rate of fuel into the boundary sublayer limits the catalytic surface reaction rate during combustion; (2) the results of the present flame quench model indicate that the flame quenches due to the heat loss to walls, and the depletion of fuel due to the catalyst coated on the combustion chamber walls does not affect flame quenching; (3) the catalysts coated on the combustion chamber surface do not contribute increased hydrocarbon emissions, but actually reduce them; (4) each catalyst has a specific surface temperature, at which the Damkoehler number for surface reaction is unity.

Nedunchezhian, N. [Department of Automobile Engineering, IRTT, Erode 638 316 (India); Dhandapani, S. [Department of Mechanical Engineering, CIT, Coimbatore 641 014 (India)

2006-01-01

401

Spontaneous Combustion and Underground Gasification of Coal: Coal-Combustion Gas. Part III.  

National Technical Information Service (NTIS)

Coal combustion gases produced under the following conditions were analyzed: combustion temperature: 700-1,000 exp 0 C; flow rate of air: 150, 200, and 250 cc/min; and air humidity: saturated at 50 or 62 exp 0 C. Also calculated were the calorific values ...

T. Yanagimoto A. Tomisaki M. Komatsu

1968-01-01

402

Toxicity of ethylene combustion condensates is directly proportional to their carbon content  

Microsoft Academic Search

Numerous epidemiological studies have shown a strong link between air pollution and human morbidity and mortality. Combustion sources are most significant contributors to the urban air pollution. So far, toxicological research has focused predominantly on combustion generated particulate matter, thereby neglecting chemical complexity of combustion exhausts. The aim of this study was to assess toxic potential of ethylene combustion condensates,

Nevena Stojicic; Christa Baumstark-Khan; Christine E. Hellweg; Horst-Henning Grotheer; Günther Reitz; Waldemar Kolanus; Ruth Hemmersbach

2010-01-01

403

Fuel combustion test in constant volume combustion chamber with built-in adaptor  

Microsoft Academic Search

Combustion tests of pre-mixture of methane and air in constant volume combustion chamber (CVCC) have been carried out by means\\u000a of flame propagation photo and gas pressure measurement, the effects of CVCC body temperature, intake pressure of pre-mixture\\u000a of methane and air, equivalence ratio and location of the built-in adaptor have been investigated. The whole combustion chamber\\u000a can be divided

HongGuang Zhang; XiaoLei Bai; DongSoo Jeong; GyuBack Cho; SuJin Choi; JinSoo Lee

2010-01-01

404

Combustion process  

SciTech Connect

A combustion catalyst containing both manganese and antimony in a temperature range of above about 1260/sup 0/ F. has been found to result in unexpactedly high CO/sub 2//CO ratios in the regenerator off-gas when CO is combusted.

McKay, D.L.

1984-07-03

405

High efficiency RCCI combustion  

NASA Astrophysics Data System (ADS)

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).

Splitter, Derek A.

406

Effect of composition of a combustible gas mixture on the parameters of a plane shock wave generated by an explosion in air  

Microsoft Academic Search

This article presents the results of calculations of the parameters of shock waves in air formed by the explosion of acetylene-oxygen and propane-air mixtures. The detonation wave is initiated along the plane of symmetry. It is assumed that the parameters of state of the air are described by the equation of an ideal gas with an adiabatic exponent of air.

A. P. Voitov; B. E. Gel'fand; S. A. Gubin; V. N. Mikhalkin; V. A. Shargatov

1984-01-01

407

Internal combustion engine with rotary combustion chamber  

SciTech Connect

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, 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 head means having 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, rotatable valving means 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, the rotatable valving means having a valving combustion chamber open to the piston chamber and the inner surface of the sleeve, the rotatable valving means having a valve body. The valving combustion chamber having an inner portion located in the valve body, the valve body having an outer surface spaced from the inner surface of the sleeve segment seal means mounted on the valve body.

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

1988-09-27

408

Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.  

PubMed

Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers. PMID:20050661

Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

2010-02-01

409

The oxygen enrichment of the Galaxy  

Microsoft Academic Search

Oxygen-to-hydrogen ratios are calculated for the 97 planetary nebulae for which there are sufficient data and for which the correction for unobserved ionization states is not too large. The ratios are strongly correlated with population type. Almost all planetaries with absolute LSR radial velocity greater than about 85 km\\/s and distance from the galactic plane greater than 1 kpc have

J. B. Kaler

1980-01-01

410

The oxygen enrichment of the galaxy  

Microsoft Academic Search

Oxygen-to-hydrogen ratios are calculated for the 97 planetary nebulae for which there are sufficient data and for which the correction for unobserved ionization states is not too large. As a part of this study, emission-line fluxes are presented for 19 planetaries. The ratios are strongly correlated with population type. Almost all planetaries with absolute LSR radial velocity greater than about

J. B. Kaler

1980-01-01

411

Difference Between IR Radiation Spectra of Ethanol in Free Diffusion Combustion Regime and Regime Influenced by an Air Flow in Modeling of a Fire Tornado  

NASA Astrophysics Data System (ADS)

Results of experimental investigations of liquid fuel combustion in the regime of a twisted jet (model of a fire tornado) are presented. Flame radiation spectra were registered. In the chosen spectral range of registration (2.2-4.8 ?m), six spectral intervals were clearly traced in which the main portion of radiated energy was concentrated. Using the ratio of the sums of spectral intensities in the vicinities of the 6th and 3rd maxima, we successfully distinguished the regimes of modeled fire tornado and free diffusion fuel combustion.

Sherstobitov, M. V.; Tsvyk, R. Sh.

2013-06-01

412

Combustion chamber and thermal vapor stream producing apparatus and method  

DOEpatents

A new and improved method and apparatus for burning a hydrocarbon fuel for producing a high pressure thermal vapor stream comprising steam and combustion gases for injecting into a subterranean formation for the recovery of liquefiable minerals therefrom, wherein a high pressure combustion chamber having multiple refractory lined combustion zones of varying diameters is provided for burning a hydrocarbon fuel and pressurized air in predetermined ratios injected into the chamber for producing hot combustion gases essentially free of oxidizing components and solid carbonaceous particles. The combustion zones are formed by zones of increasing diameters up a final zone of decreasing diameter to provide expansion zones which cause turbulence through controlled thorough mixing of the air and fuel to facilitate complete combustion. The high pressure air and fuel is injected into the first of the multiple zones where ignition occurs with a portion of the air injected at or near the point of ignition to further provide turbulence and more complete combustion.

Sperry, John S. (Houston, TX); Krajicek, Richard W. (Sugar Land, TX); Cradeur, Robert R. (Spring, TX)

1978-01-01

413

Combustion systems  

SciTech Connect

This patent describes an external combustion engine such as a Stirling engine and the like, having an external heat system housing in which is defined a heater space, a hollow liner formed of a ceramic material disposed in the heater space and defining a combustion chamber. Biasing means are coupled to a first end of the liner and coupled with the housing so as to maintain the liner in the heater space while dampening transmission of vibration in the housing to the liner.

Kralick, J.

1986-03-04

414

Measurements of Aluminum Combustion in Energetic Formulations  

Microsoft Academic Search

Aluminum combustion plays an important role in tailoring energy release rates of energetic materials. The intimate mixing between Al and oxidizers from the formulation itself or from the surrounding atmosphere is key to effecting combustion. We infer combustion processes in detonated aluminized energetic formulations PBXIH-135 and PBXN-111 in air using time-resolved spectroscopy. We recorded spectral emissions from Al and AlO

J. Scott Miller; G. I. Pangilinan

2004-01-01

415

40 CFR 60.1855 - What records must I keep for municipal waste combustion units that use activated carbon?  

Code of Federal Regulations, 2010 CFR

...combustion units that use activated carbon? 60.1855 Section...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED...combustion units that use activated carbon? For municipal waste...combustion units that use activated carbon to control...

2010-07-01

416

40 CFR 60.1370 - What records must I keep for municipal waste combustion units that use activated carbon?  

Code of Federal Regulations, 2010 CFR

...combustion units that use activated carbon? 60.1370 Section...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED...combustion units that use activated carbon? For municipal waste...combustion units that use activated carbon to control...

2010-07-01

417

40 CFR 62.15310 - What records must I keep for municipal waste combustion units that use activated carbon?  

Code of Federal Regulations, 2010 CFR

...combustion units that use activated carbon? 62.15310 Section...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED...combustion units that use activated carbon? For municipal waste...combustion units that use activated carbon to control...

2010-07-01

418

40 CFR 62.15310 - What records must I keep for municipal waste combustion units that use activated carbon?  

Code of Federal Regulations, 2010 CFR

...combustion units that use activated carbon? 62.15310 Section...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED...combustion units that use activated carbon? For municipal waste...combustion units that use activated carbon to control...

2009-07-01

419

COâ emission abatement in IGCC power plants by semiclosed cycles: Part B -- With air-blown combustion and COâ physical absorption  

Microsoft Academic Search

This paper analyzes the fundamentals of IGCC power plants with carbon dioxide removal systems, by a cycle configuration alternative to the one discussed in Part A (with oxygen-blown combustion). The idea behind this proposal is to overcome the major drawbacks of the previous solution (large oxygen consumption and re-design of the gas turbine unit), by means of a semiclosed cycle

P. Chiesa; G. Lozza

1999-01-01

420

Shortcomings in USEPA's Approach for Predicting Risk Due to Consumption of Animal Food Products Impacted by Air Emissions from Hazardous Waste Combustion Facilities: A Case Study Involving Phthalates  

Microsoft Academic Search

As a part of the permitting process for hazardous waste combustion facilities, regulatory agencies are now conducting site-specific, multipathway risk assessments. In accordance with the approach established by the USEPA, the Texas Natural Resource Conservation Commission uses a prospective risk assessment paradigm whereby site-specific activity pattern and land use information is used to determine plausible exposure scenarios and pathways. A

Roberta L. Grant; Rosita J. Rodriguez; Chris S. Hofelt; Laurie C. Haws

2002-01-01

421

Removing aromatic and oxygenated VOCs from polluted air stream using Pt-carbon aerogels: assessment of their performance as adsorbents and combustion catalysts.  

PubMed

Two series of Pt-catalysts were prepared by impregnation or doping of carbon aerogels and different porous textures and Pt-dispersion were obtained. The performance of the samples in the elimination of organic compounds (VOCs) by adsorption and catalytic combustion was studied and compared with the characteristics of both the VOCs and the catalysts and the interactions between them. Toluene, xylenes and acetone were selected as representative aromatic or oxygenated VOCs. The adsorption of VOCs is favoured at room temperature in the case of meso/microporous materials, but at the higher catalytic reaction temperature, the micropores volume is more important. Adsorption and catalytic combustion occur simultaneously, and are both dependent on temperature, albeit in opposite directions. The combustion of aromatic compounds takes place at a lower temperature than that required for acetone combustion, so favouring the accumulation of adsorbed VOC, something that should be avoided to minimize risks. Catalytic performance improves with the contact time and is independent of oxygen content above 5% v/v, but declines significantly below this limit. PMID:21872395

Maldonado-Hódar, Francisco José

2011-08-05

422

Combustion gas heat recovery apparatus  

SciTech Connect

A secondary heat exchanger is positioned within a cold air return plenum of a forced air gas or oil fired furnace to preheat cold air drawn into the furnace through the cold air plenum. A heat recovery flue pipe is connected between a primary flue pipe of the furnace and the secondary heat exchanger, and an exhaust pipe is connected between the secondary heat exchanger and the outside of a structure served by the furnace. A secondary blower coupled to the exhaust pipe draws hot combustion gases from the primary flue pipe through the heat exchanger and exhausts cooled combustion gases to the outside. The secondary heat exchanger comprises a combustion gas inlet plenum and a combustion gas outlet plenum, with a plurality of heat conducting pipes sealingly connected therebetween. Each of the heat conducting pipes is arranged to define a circuitous path between the inlet plenum and the outlet plenum, with each heat conducting pipe defining at least two aligned linear radiating surfaces over which cold air is drawn. Heat conducting fins are intimately connected to the heat conducting pipes and a condensate drain is provided in the lower extremities of the heat conducting pipes to drain condensate from the secondary heat exchanger.

McCann, A.

1985-12-17

423

Jet plume injection and combustion system for internal combustion engines  

DOEpatents

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure. 24 figures.

Oppenheim, A.K.; Maxson, J.A.; Hensinger, D.M.

1993-12-21

424

Combustion liner for a gas turbine engine  

Microsoft Academic Search

This patent describes, for a gas turbine power plant, a combustor having panels generally circular in shape and extending axially arranged end to end to define an annular combustion chamber. Each of the panels have an inner surface subjected to combustion gases and an outer surface subjected to power plant cooler air. It also has means on the downstream end

1986-01-01

425

Visualizing combustion using electrical impedance tomography  

Microsoft Academic Search

The techniques developed for electrical capacitance tomography (ECT) have been adapted to characterize combustion phenomena in a scaled model of an internal combustion engine. The method is able to locate flame position, measure flame size and monitor the effect of varied air\\/fuel ratio. Flame failure can be identified. The technique can measure flame front arrival time and reliably depict the

Roger C. Waterfall; Ruhua He; Christopher M. Beck

1997-01-01

426

Engine combustion chamber structure  

SciTech Connect

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.

Tanaka, H.

1988-09-13

427

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...

428

Proceedings of the 1998 international joint power generation conference (FACT-Vol.22). Volume 1: Fuels and combustion technologies; Gas turbines; Environmental engineering; Nuclear engineering  

Microsoft Academic Search

Papers are arranged under the following topical sections: Fuels and combustion technologies; Low NOx burner applications; Low cost solutions to utility NOx compliance issues; Coal combustion--Retrofit experiences, low NOx, and efficiency; Highly preheated air combustion; Combustion control and optimization; Advanced technology for gas fuel combustion; Spray combustion and mixing; Efficient power generation using gas turbines; Safety issues in power industry;

A. Gupta; R. Natole; A. Sanyal; J. Veilleux

1998-01-01

429

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

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

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

1979-01-01

430

Method of controlling a free piston external combustion engine  

Microsoft Academic Search

A method is described for controlling the operation of an external combustion engine wherein the engine comprises: a compressor for compressing ambient air for supply to a combustion member including a free piston travelling between two end closures of a sleeve in which the piston slides reciprocatingly thus defining two combustion chambers between each end closure and the corresponding end

1987-01-01

431

Initiation of Combustion in Lean Mixtures by Flame Jets  

Microsoft Academic Search

Flame jets produced by Pulsed Combustion Jet (PCJ) systems are particularly suited for initiating combustion in lean fuel-air mixtures. Presented here is a detailed investigation of performance characteristics of a PCJ system. The progress of combustion in the cavity of a generator was observed by schlieren photography of the events occurring in the interior of a rectangular cavity simulator fitted

E. MURASE; S. ONO; K. HANADA; A. K. OPPENHEIM

1996-01-01

432

Performance of pulsed combustion jet at high pressures and temperatures  

Microsoft Academic Search

Ignition and combustion by Pulsed Combustion Jet (PCJ) at high pressures and temperatures were investigated using a compact rapid compression machine. The compression and stop motion of a compression piston in the rapid compression machine is controlled by the cam shape, and the cam is operated by a driving piston and compressed air. The combustion process was monitored by pressure

Eiichi Murase; Shinsuke Ono; Kunihiko Hanada; Jyong Ho Yun; Antoni K. Oppenheim

1996-01-01

433

Experimental investigation of NO x emissions in oxycoal combustion  

Microsoft Academic Search

This work presents the results of an experimental investigation on NOx emissions from coal combustion in a pilot scale test facility. Three oxidiser atmospheres have been compared, namely air, CO2\\/O2, and O2 enriched recirculated flue gas. NOx emissions from two different combustion modes have been studied, swirl flame and flameless combustion. The influence of the burner oxygen ratio and the

Hannes Stadler; Dominik Christ; Martin Habermehl; Peter Heil; Arno Kellermann; Andreas Ohliger; Dobrin Toporov; Reinhold Kneer

2011-01-01

434

Mild combustion in a laboratory-scale apparatus  

Microsoft Academic Search

Mild oxidation is one of the promising techniques proposed to control pollutant emissions from combustion plants. It is characterized by high preheating of combustion air and massive recycle of burned gases before reaction. These requisites lead to high combustion efficiency and good control of thermal peaks and hot spots, lowering NO x thermal emissions. In this work, a laboratory-scale burner

Alessandro Cavigiolo; Mauro A. Galbiati; Alessandro Effuggi; Davino Gelosa; Renato Rota

2003-01-01

435

MODELING NON-EQUILIBRIUM CO OXIDATION IN COMBUSTION SYSTEMS  

Microsoft Academic Search

Performance of industrial and utility combustion systems is becoming increasingly affected by limits on pollutant emissions such as NOx and CO. CO emissions impact design and operation of combustion systems, particularly when coupled with NOx reduction technologies that involve lower temperature operation or staged firing. Lower combustion temperatures or delayed mixing of fuel and air helps minimize NOx formation, but

Bradley R. Adams; Marc A. Cremer; Dave H. Wang

2000-01-01

436

Pressurized fluidized bed Combustion technology  

Microsoft Academic Search

The technology of pressurized fluidized bed combustion (PFBC), particularly in its application to a coal-burning combinedcycle (CC) plant, is evaluated in this book. Engineering systems analyses are performed for advanced concept plant components-boiler systems, including combustors, air-handling and air-injection equipment, and heat exchangers; solids handling, injection and ejection systems; hot-gas cleanup equipment; instrumentation and control systems; and turbines-and materials of

W. F. etc. Podolski; R. L. etc. Graves

1983-01-01

437

Pilot-scale evaluation of the potential for emissions of hazardous air pollutants from combustion of tire-derived fuel. Final report, February 1992October 1993  

Microsoft Academic Search

Experiments were conducted in a 73kW (250,000 Btu\\/hr) rotary kiln incinerator simulator to examine and characterize emissions from incineration of scrap tire material. The purposes of this project are to: (1) generate a profile of target analytes for full-scale stack sampling efforts, not to generate statistically defensible emission factors for the controlled combustion of scrap tire material; and (2) where

Lemieux

1994-01-01

438

A Study of Air Pollutant Emission from Residential Heating Systems.  

National Technical Information Service (NTIS)

The report presents results of recent EPA research into the problem of air pollutant emissions from small-scale combustion systems. Major factors for controlling emission levels were found to be: excess air, residence time at high temperature, combustion ...

R. E. Hall J. H. Wasser E. E. Berkau

1974-01-01

439

Biofuels combustion.  

PubMed

This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly. PMID:23298249

Westbrook, Charles K

2013-01-04

440

Apparatus for control of pressure in internal combustion engines  

SciTech Connect

This patent describes an internal combustion engine including a variable volume combustion chamber into which is admitted a fuel air charge during at least part of an intake and compression event forming part of the operating cycle of the engine, such charge being compressed during at least part of the intake and compression event, reacted during a combustion/expansion event, and discharged during an exhaust event; a piston means movable within a cylinder to vary its volume between the piston means and the head of the cylinder; means for independently supplying air and fuel to the combustion chamber in timed relationship with the movement of the piston means, and inlet and exhaust valves for controlling admission of air and fuel into the combustion chamber through an intake port and discharging of combustion products from the combustion chamber through an exhaust product respectively. The improvement includes: means for supplying substantially fuel-free air alone to a combustion chamber, means for supplying fuel into the combustion chamber during a later part of each charge intake and compressing event, whereby the proportion of fuel to air of each charge varies from excess fuel near the intake port, an air reservoir chamber means, a passageway between the combustion chamber and reservoir chamber.

Blaser, R.F.

1992-06-02

441

INDUCED SECONDARY COMBUSTION IN WOODSTOVES  

EPA Science Inventory

The paper provides information useful for woodstove designers concerned with reducing emissions. A dual-chamber woodstove was modified to induce secondary combustion by utilizing an ignition source and forced flow of secondary air. The ignition source was an electric glow plug in...

442

Apparatus for control of pressure in internal combustion engines  

SciTech Connect

This patent describes improvement in an internal combustion engine including a variable volume combustion chamber into which is admitted a fuel air charge during at least part of an intake and compression event forming part of the operating cycle of the engine, such charge being compressed during at least part of the intake and compression event, reacted during a combustion/expansion event, and discharged during an exhaust event; a piston means moveable within a cylinder to vary its volume between the piston means and the head of the cylinder, the combustion chamber disposed between the working face of the piston means and the head of the cylinder; means for independently supplying air and fuel to the combustion chamber in timed relationship with the movement of the piston means, and inlet and exhaust valves for admitting air and fuel into the combustion chamber through an intake port and discharging of combustion products from the combustion chamber through an exhaust port, respectively. The improvement comprises: means for supplying substantially fuel-free air alone to the combustion chamber through the intake porting during the initial part of each charge intake and compression events; means for supplying fuel into the combustion chamber during a later part of each charge intake and compression event following the initial part, whereby the proportion of fuel to air of each charge varies from excess fuel near the intake port to substantially fuel-free air near the piston means at the beginning of the compression event; an air reservoir chamber means; a gap between the combustion chamber and air reservoir chamber, the gap forming a passageway providing restricted communication between the reservoir chamber and combustion chamber; the air reservoir chamber means located next to the working face of the piston and having a radially inner sidewall.

Blaser, R.F.; Pouring, A.A.

1992-03-17

443

Stratified combustion type engine  

Microsoft Academic Search

The present invention relates to a stratified combustion type engine comprising an engine cylinder, a main combustion chamber located above the cylinder, an injection nozzle for injecting auxiliary fuel towards the combustion chamber, and an open pre-combustion chamber provided within the combustion chamber for locally holding and vaporizing the flow of auxiliary fuel from the injection nozzle. The pre-combustion chamber

Kamiya

1977-01-01

444

Stratified combustion type engine  

Microsoft Academic Search

A stratified combustion type engine is described that is comprised of an engine cylinder, a main combustion chamber located above the cylinder, an injection nozzle for injecting auxiliary fuel towards the combustion chamber, and an open pre-combustion chamber provided within the combustion chamber for locally holding and vaporizing the flow of auxiliary fuel from the injection nozzle. The pre-combustion chamber

Kamiya

1978-01-01

445

Internal combustion engine injection superheated steam  

SciTech Connect

This patent describes a method for introducing water vapor to the combustion chambers of an internal combustion engine. It comprises: introducing a metered amount of liquid water into a heat exchanger; contacting the heat exchanger directly with hot exhaust gases emanating from the exhaust manifold; maintaining the water in the heat exchanger for a period sufficient to vaporize the water into steam and superheat same; reducing pressure and increasing temperature to create superheated steam; introducing the superheated steam into the air supply proximate to the air induction system, upstream of any carburetion, of the internal combustion engine.

Mahoney, F.G.

1991-01-22

446

Gas turbine alternative fuels combustion characteristics  

NASA Astrophysics Data System (ADS)

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 in terms of released heat and combustion gas emission values. The results were comparable to those obtained with the base fuels with variations being obtained with changing operating conditions. The release of carbon particles during the tests was minimal.

Rollbuhler, R. James

1989-02-01

447

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

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

Hosseini, Seyedali; Niaei, Aligholi; Salari, Dariush

2012-01-01

448

Experimental investigation of the prevaporized premixed (vpl) combustion process for liquid fuel lean combustion  

Microsoft Academic Search

A novel concept for the preparation of liquid fuels for an environmentally benign combustion process has been developed. This concept, called ‘VPL’ (Vaporized Premixed Lean) combustion, consists of:1.a separate fuel flash vaporizer in which the liquid fuel is converted to the gaseous state;2.a static mixing device for homogeneous mixing of fuel vapor and combustion air;3.a burner in premixed mode, thus

Ming Wei; Yunhong Wang; Lothar Reh

2002-01-01

449

Primary zone air proportioner  

DOEpatents

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.

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

1982-10-12

450

Got Dirty Air?  

NSDL National Science Digital Library

Students are introduced to the concepts of air pollution and technologies that have been developed by engineers to reduce air pollution. Students develop an understanding of visible air pollutants with an incomplete combustion demonstration, a âsmog in a jarâ demonstration, construction of simple particulate matter collectors and by exploring engineering roles related to air pollution. Next, students develop awareness and understanding of the daily air quality and trends in air quality using the Air Quality Index (AQI) listed in the newspaper. Finally, students build and observe a variety of simple models in order to develop an understanding of how engineers use these technologies to clean up and prevent air pollution.

Integrated Teaching And Learning Program

451

Induction system for internal combustion engine  

SciTech Connect

An induction system is described for an internal combustion engine having first and second groups of cylinders of which firing orders are respectively discontinuous. It consists of: a first collector for supplying air to the first group of cylinders; a second collector for supplying air to the second group of cylinders; a first main air supply passage fluidly connected to the first collector to form a first supply line; a second main air supply passage fluidly connected to the second collector to form a second air supply line independent from the first air supply line; a first throttle valve disposed in the first main or supply passage; a second throttle valve disposed in the first main air supply passage; an additional air supply passage bypassing the first and second throttle valves for supplying additional air to the first and second collectors; and an additional air control valve disposed in the additional air supply passage for controlling air flow therethrough.

Ura, S.; Kikuchi, T.; Yasuda, M.

1987-10-20

452

Multi-fuel system for internal combustion engines  

Microsoft Academic Search

A multi-fuel system is described for an internal combustion engine which consists of: a carburetor having an air inlet and a fuel inlet and means for mixing the air and liquid fuel to form a combustible mixture which is conducted to the engine to operate the same; a first liquid fuel supply assembly having means for regulating the pressure of

O. V. Phillips; W. R. Phillips

1986-01-01

453

MONITORING STRATEGIES FOR FLUIDIZED BED COMBUSTION COAL PLANTS  

EPA Science Inventory

Air and water monitoring strategies for commercial-size Fluidized Bed Combustion (FBC) coal plants are presented. This is one of five reports developing air and water monitoring strategies for advanced coal combustion (FBC), coal conversion (coal gasification and liquefaction), a...

454

Precise combustion-control saves fuel and power  

Microsoft Academic Search

Instrumentation assuring a minimum amount of excess air for combustion of fuels improves the importance and increases the thermal efficiency of boilers, furnaces, and kilns. This has now become an important factor due to increased fuel prices. To achieve good combustion control and the best fuel-burning efficiency requires that two fundamental conditions be established: exact balancing of the air\\/fuel ratio

1975-01-01

455

14 CFR 25.859 - Combustion heater fire protection.  

Code of Federal Regulations, 2010 CFR

...duct passing through any fire zone must be fireproof...means, the ventilating air duct downstream of each...enough to ensure that any fire originating in the heater...airstream. (c) Combustion air ducts. Each combustion...condition, including reverse flow or malfunctioning of...

2010-01-01

456

14 CFR 23.859 - Combustion heater fire protection.  

Code of Federal Regulations, 2010 CFR

...duct passing through any fire region must be fireproof...means, the ventilating air duct downstream of each...enough to ensure that any fire originating in the heater...airstream. (c) Combustion air ducts. Each combustion...condition, including reverse flow or malfunctioning of...

2009-01-01

457

Flow measurements in a model ramjet secondary combustion chamber  

Microsoft Academic Search

Experimental studies were conducted on a typical secondary combustion chamber of a ramjet to understand the influence of various inlet parameters such as primary nozzle configuration, secondary air injection angle, and flow Reynolds numbers on the secondary combustion chamber (SCC) performance. Cold flow studies were made with air as the flow medium for both primary and secondary jets followed by

Lazar T. Chittilapilly; S. Venkateswaran; P. J. Paul; H. S. Mukunda

1990-01-01

458

Chemical-looping combustion using syngas as fuel  

Microsoft Academic Search

Chemical-looping combustion (CLC) is a combustion technology where an oxygen carrier is used to transfer oxygen from the combustion air to the fuel, avoiding direct contact between air and fuel. Thus, CO2 and H2O are inherently separated from the rest of the flue gases and the carbon dioxide can be obtained in a pure form without the use of an

Tobias Mattisson; Francisco García-Labiano; Bernhard Kronberger; Anders Lyngfelt; Juan Adánez; Hermann Hofbauer

2007-01-01

459

Measurement of air toxic emissions from a coal-fired boiler equipped with a tangentially-fired low NOx combustion system  

Microsoft Academic Search

This paper presents the results of measurements of chemical emissions from a coal-burning, tangentially-fired, utility boiler equipped with a hot-side electrostatic precipitator and a low NOx firing system. The tests were conducted in response to Title III of the 1990 Amendments to the Clean Air Act which lists 189 chemicals to be evaluated as {open_quotes}Air Toxics.{close_quotes} The project was jointly

E. B. Dismukes; R. J. Clarkson; R. R. Hardman; G. G. Elia

1993-01-01

460

Experimental investigation of three-dimensional flame-front structure in premixed turbulent combustion—I: hydrocarbon\\/air bunsen flames  

Microsoft Academic Search

OH concentrations and three-dimensional gradients of the reaction progress variable have been measured in turbulent liquefied petroleum gas\\/air and compressed natural gas\\/air premixed flames stabilized on a Bunsen-type burner with a combined two-sheet Rayleigh scattering and planar LIF-OH imaging technique. The progress variable is observed to undergo a transition from lamella-like to non-flamelet front structure with increasing turbulence. This is

Yung-Cheng Chen; Robert W. Bilger

2002-01-01

461

Method for the Controlled Burning of Combustible Materials and Analyses of the Combustion Gases  

Microsoft Academic Search

A method is described to burn a given quantity of a combustible material in a fixed amount of air at a selected initial temperature. Analyses of most of the gaseous combustion products were made quickly and comprehensively by means of a mass spectrometer. Hydro­ gen chloride was not detected with the mass spectrometer because of its adsorption upon the walls

Alan Schriesheim

462

Comparison of Different Global Reaction Mechanisms for MILD Combustion of Natural Gas  

Microsoft Academic Search

Emissions of nitrogen oxides from fossil fuel combustion are a major environmental problem because they have been shown to contribute to the formation of acid rain and photochemical smog. MILD (Moderate and Intensive Low oxygen Dilution) combustion is a promising technology to decrease pollutant emissions and to improve combustion efficiency. A combination of air preheating and fuel dilution with combustion

Ju Pyo Kim; Uwe Schnell; Günter Scheffknecht

2008-01-01

463

Group combustion of coal particles:  

SciTech Connect

As opposed to individual particle combustion (IPC) modeling, a group combustion (GC) theory is proposed for the combustion modeling of charcarbon particles. The group behavior for a cloud of particles represents the change in the burning characteristics due to collective behavior of particles with or without a group flame. To gain a basic understanding of the group behavior, a simple model such as the steady state analysis of a spherically symmetric cloud of charcarbon particles burning in quiescent air, was used to obtain results for the cloud burning rate. The most important objective was to relate the results from individual particle combustion (IPC) model to the Group Combustion (GC) model. This second annual report deals with experimental correlation of steady state results, non-steady group ignition and combustion of a cloud of char particles. A computer code based on the non-steady model was developed and using this code, steady state was simulated and the results were compared with the explicit results. The results are presented for cases with frozen gas phase and also for cases with gas phase CO oxidation reaction along with CO/sub 2/ reduction at the char surface. 40 refs

Annamalai, K.; Ramalingam, S.C.; Ryan, W.R.

1987-12-01

464

Combustion in porous media  

SciTech Connect

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.

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

1999-09-01

465

63 FR 18754 - National Emission Standards for Hazardous Air Pollutants; Proposed Standards for Hazardous Air...  

Federal Register 2010, 2011, 2012, 2013

...63 National Emission Standards for Hazardous Air Pollutants; Proposed Standards for Hazardous Air Pollutants From Chemical Recovery Combustion...2060-AD03 National Emission Standards for Hazardous Air Pollutants; Proposed Standards for...

1998-04-15

466

Air-fuel ratio control system  

Microsoft Academic Search

An air-fuel ratio control system for an internal combustion engine including an automobile carburetor having a fuel passage for forming a combustible air-fuel mixture by mixing fuel fed through the fuel passage with air drawn from the atmosphere, comprises a catalytic converter for substantially purifying exhaust gases emitted from the engine, a composition sensor for sensing the concentration of a

Matsuoka

1982-01-01

467

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

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

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

2003-11-01

468

Gas turbine combustion  

Microsoft Academic Search

This text focuses on the fundamentals of gas turbine combustion, emphasizing combustor design and performance. The material presented is based on the latest research results. Aerodynamic and heat transfer processes in gas turbine combustors as well as the combustion performance parameters of ignition, combustion efficiency, and stability are described. Some of the topics covered are combustion fundamentals; diffusers; aerodynamics; combustion

1983-01-01

469

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

NASA Astrophysics Data System (ADS)

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.

Li, Guoqiang

470

Changes in the quality of coal combustion by-products produced by Kentucky power plants, 1978 to 1997: consequences of Clean Air Act directives  

Microsoft Academic Search

The original US Clean Air Act (CAA), implemented by the Environmental Protection Agency in 1971, and the amendments to the act in 1977 and 1990 have required a considerable evolution of the quality of coal burned by utilities and in the type pollution control equipment needed to reduce SO2 and NOx emissions. Any change in coal quality or emission’s control

James C. Hower; Thomas L. Robl; Gerald A. Thomas

1999-01-01

471

Pressurized Fluidized Bed Combustion of Sewage Sludge  

NASA Astrophysics Data System (ADS)

A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of the dry and wet sewage sludge were carried out by using laboratory scale pressurized fluidized bed combustors. Combustibility of the sewage sludge was good enough and almost complete combustion was achieved in the combustion of the actual wet sludge. CO emission and NOx emission were marvelously low especially during the combustion of wet sewage sludge regardless of high volatile and nitrogen content of the sewage sludge. However, nitrous oxide (N2O) emission was very high. Hence, almost all nitrogen oxides were emitted as the form of N2O. From these combustion tests, we judged combustion of the sewage sludge with the pressurized fluidized bed combustor is suitable, and the conceptual design of the power generation system is available.

Suzuki, Yoshizo; Nojima, Tomoyuki; Kakuta, Akihiko; Moritomi, Hiroshi

472

Effect of diluted and preheated oxidizer on the emission of methane flameless combustion  

NASA Astrophysics Data System (ADS)

In combustion process, reduction of emissions often accompanies with output efficiency reduction. It means, by using current combustion technique it is difficult to obtainlow pollution and high level of efficiency in the same time. In new combustion system, low NOxengines and burners are studied particularly. Recently flameless or Moderate and Intensive Low oxygen Dilution (MILD) combustion has received special attention in terms of low harmful emissions and low energy consumption. Behavior of combustion with highly preheated air was analyzed to study the change of combustion regime and the reason for the compatibility of high performance and low NOx production. Sustainability of combustion under low oxygen concentration was examined when; the combustion air temperature was above the self-ignition temperature of the fuel. This paper purposes to analyze the NOx emission quantity in conventional combustion and flameless combustion by Chemical Equilibrium with Applications (CEA) software.

Hosseini, Seyed Ehsan; Salehirad, Saber; Wahid, M. A.; Sies, Mohsin Mohd; Saat, Aminuddin

2012-06-01

473

Pulsating Combustion Device Miniaturization.  

National Technical Information Service (NTIS)

The phenomenon of pulsating combustion remains one of the least understood forms of combustion. In this thesis, combustion oscillations are classified into the categories of chamber oscillations, system oscillations, and intrinsic oscillations. Two pulsat...

R. K. Crowe

1976-01-01

474

Fuel injected internal combustion engine pollutant control system  

Microsoft Academic Search

A fuel injected internal combustion engine is described comprising: an air intake apparatus having at least one resistance heating element capable of heating air passing therethrough to a temperature within a range of 160°F to 180°F, and an air temperature sensing means situated downstream of the resistance heating element to control the temperature of the heating element; combustion chamber means

Rawlings

1987-01-01

475

Influence of outer secondary-air vane angle on combustion characteristics and NO x emissions of a down-fired pulverized-coal 300 MWe utility boiler  

Microsoft Academic Search

Industrial experiments were performed on a down-fired pulverized-coal 300MWe utility boiler with swirl burners. Gas temperature, concentrations of gas components (O2, CO, CO2