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Fundamental Investigation of NOx Formation in Diesel Combustion Under Supercharged and EGR Conditions
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 11, 2005 by SAE International in United States
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Aim of this study is to clarify the NOx formation mechanism in diesel combustion under high-supercharged condition. Effects of ambient conditions and fuel injection parameters on diesel combustion were investigated using a constant volume chamber. NOx formation process was investigated using a total gas-sampling device. The results indicate that by using the above experimental setup it is possible to realize entirely diffusion combustion like what seen in the highly supercharged condition. Increasing ambient pressure up to 8MPa with high injection pressure shortens the ignition delay and offers a heat release rate proportional to the fuel injection rate with a short combustion duration. Increasing ambient pressure gives a higher NOx formation rate and final NOx concentration. This is due to enhancement in the fuel-air mixing which promotes the heat release. Increasing injection pressure increases the NOx formation rate during the heat release, however reduces the final NOx mass per released heat. Lowering oxygen concentration in the range of this study shows slight effects on the combustion trend, however, it greatly reduces the NOx formation rate and final NOx concentration.
To better understand the above phenomena, a spray combustion model was developed based on stochastic mixing model including NO formation scheme. Generally the calculation results well reproduce the experimental results. The analysis of calculated result reveals the role of fuel-air mixing in the NOx formation under entirely diffusion combustion with a low overall equivalence ratio. In the early stage of combustion, rich mixtures are diluted with air and fall into the equivalence ratio range of high NO production rate. Then, the mixtures are further diluted and shift to the state of freezed NO formation. According to this mechanism, the experimental results on effects of ambient pressure and injection pressure are reasonably described.
CitationKitamura, Y., Mohammadi, A., Ishiyama, T., and Shioji, M., "Fundamental Investigation of NOx Formation in Diesel Combustion Under Supercharged and EGR Conditions," SAE Technical Paper 2005-01-0364, 2005, https://doi.org/10.4271/2005-01-0364.
In-Cylinder Diesel Particulate and NOx Control 2005
Number: SP-1976 ; Published: 2005-04-11
Number: SP-1976 ; Published: 2005-04-11
- Shundoh, S., et al., The Effect of Injection Parameters and Swirl on Diesel Combustion With High-pressure Fuel Injection, SAE Paper No.910489, (1991).
- Mikulic, L., et al., Exhaust Emission Optimization of DI Diesel Passenger Car Engine with High-pressure Fuel Injection and EGR, SAE Paper No.931035, (1993).
- Minami, T., et al., Reduction of Diesel Engine NOx using Pilot Injection, SAE Paper No.950611, (1995).
- Eastwood, P., Critical Topics in Exhaust Gas Aftertreatment, Research Studies Press ltd., (2000).
- Watson, N. and Janota, M.S., Turbocharging The Internal Combustion Engine, The Macmillan Press ltd., (1982).
- Endo, S., et al, State-of-the-Art; Hino High Boosted Diesel Engine, SAE Paper No.931867, (1993).
- Tanin, K.V., et al, The Influence of Boot Pressure on Emissions and Fuel Consumption of a Heavy-Duty Single-Cylinder D.I., Diesel Engine, SAE Paper No.1999-01-0840, (1999).
- Aoyagi, Y., et al., Diesel Combustion and Emission Study by Using of High Boost and High Injection Pressure in Single Cylinder Engine, Proc. Int. Symp. COMODIA 2004, (2004), pp.119-126.
- Benajes, J., et al, Influence of Boost Pressure and Injection Pressure on Combustion Process and Exhaust Emissions in a HD Diesel Engine, SAE Paper No.2004-01-1842, (2004).
- Misawa, M., et al., High EGR Diesel Combustion and Emission Reduction Study by Single Cylinder Engine, Proc. Int. Symp. COMODIA 2004, (2004), pp.59-64.
- Desates, J.M., et al., Influence of In-cylinder Gas Density and Injection Pressure on the Combustion Process and Emissions in a Heavy-Duty Diesel Engine, FISITA 2002 World Congress, Helsinki, (2002).
- Shrivastava, R., Hessel, R. and Reitz, R.D., CFD Optimization of DI Diesel Engine Performance and Emissions Using Variable Intake Valve Actuation with Boost Pressure, EGR and Multiple Injections, SAE Paper No.2002-01-0959, (2002).
- Zhang, L., Takatsuki T. and Yokota, K., An Observation and Analysis of the Combustion under Supercharging on a Diesel Engine, SAE Paper No.940844, (1994).
- Ryan, T.W. and Shahed S.M., Injection Pressure and Intake Air Density Effects on Ignition and Combustion in a 4-Valve Diesel Engine, SAE Paper No.941919, (1994).
- Crua, C., Kennaird, D.A. and Heikal, M.R., Laser-induced Incandescence Study of Diesel Soot Formation in a Rapid Compression Machine at Elevated Pressures, Combust. Flame, Vol.135, (2003), pp.475-488.
- Picket, L.M. and Siebers, D.L., Soot in Diesel Fuel Jets: Effects of Ambient Temperature, Ambient Density and Injection Pressure. Combust. Flame, Vol.138, (2004), pp.114-135.
- Mohammadi, A., Kidoguchi, Y. and Miwa, K., Effect of Injection Parameters and Wall-Impingement on Atomization and Gas Entrainment Processes in Diesel Sprays, SAE Paper No.2002-01-0497, (2002).
- Aoyagi, Y., et al., A Gas-sampling Study on The Formation Processes of Soot and NO in a DI Diesel Engine, SAE Paper No.80254, (1980).
- Vioculecu, I.A. and Borman, G.L., An Experimental Study of Diesel Engine Cylinder-Averaged NO Histories, SAE Paper No.780228, (1978).
- Mohammadi, A., Miwa, K. and Kidoguchi, Y., Effects of Injection Pressure and Fuel Properties on NOx Formation during Diesel Combustion, Trans. of JSAE, vol.32, No. 4, (2001), pp.23-28.
- Miwa, K., Mohammadi, A. and Kidoguchi, Y., A Study on Thermal Decomposition of Fuels and NOx Formation in Diesel Combustion Using a Total Gas Sampling Technique, Int. J. of Engine Research, Vol.2, No. 3, (2001), pp.189-198.
- Dec, J.E. and Canaan, R.E., PLIF Imaging of NO Formation in a DI Diesel Engine, SAE Paper No.980147, (1998).
- Ikegami, M., Ishiyama, T., Nakatani, K., Ohtani, T. and Nakai, S., Effect of Exhaust Gas Recirculation and Injection Pressure on Exhaust Emissions from a Diesel Engine, Proc. Int. Symp. COMODIA98, (1998), pp.87-92.
- Siebers, D.L., Ignition Delay Characteristics of Alternative Diesel Fuels: Implications on Cetane Number, Trans. SAE, Vol.94, Paper No.852102, (1985), pp.673-686.
- Ikegami, M., Shioji, M. and Koike, M., A stochastic Approach to Model the Combustion Process in Direct-Injection Diesel Engines, Proc.20th Symp. (Int.) on Combust. (1984), pp.217-224.
- Nakatani, K., Shioji, M., Ihara,T. and Ikegami, M., Prediction of Ignition Delay of a Diesel Spray by Stochastic Model, Prepr. of jpn. Soc. Mech. Eng.,No.994-1, (1999), pp.5-21 - 5-22. (in Japanese)
- Ikegami, M., Nakatani, K. and Shioji, M., Prediction of Ignition Process in Diesel Sprays by Stochastic Model, Trans. Jpn. Soc. Mech. Eng., Vol.65, No.595, B, (1999), pp.3489-3496. (in Japanese)
- Ishiyama, T., Shioji, M., Ihara, T and Katsuura, A, Modeling and Experiments on Ignition of Fuel Sprays Considering the Interaction Between Fuel-Air Mixing and Chemical Reactions, SAE Paper No.2003-01-1071, (2003).
- Raine, R.R, Stone, C.R and Gould, J., Modeling of nitric oxide formation in spark ignition engines with a multizone burned gas, Combust. Flame, Vol.102-3, (1995), pp.241-255.