Impact of Exhaust Gas Recirculation on Performance and Emissions of Free-Piston Electrical Generator Fueled by DME
Publication: Journal of Energy Engineering
Volume 144, Issue 3
Abstract
This study presents a novel and interesting investigation regarding the use of exhaust gas recirculation (EGR) in free-piston engines by exploring EGR impact on both engine performance and emissions. A single-cylinder, two-stroke free-piston engine with an electrical generator model was investigated under the influence of EGR. A new dimethyl ether (DME) reaction mechanism was modified and used to simulate the DME combustion process under homogenous charge compression ignition conditions. The combustion process was described using the one-dimensional approach in which the in-cylinder gas mixture was treated as a single-zone reactor. Chemical kinetics approach was applied to calculate the combustion heat releasing rate and to include EGR effects. Many engine parameters were investigated by applying EGR in different ratios and in different temperatures. The results showed that EGR influences the combustion process by shifting the top dead center location toward the cylinder head, which yields higher compression ratio but shorter ignition delay. The engine ran with less generator power output when EGR was applied but with higher overall efficiency, meaning that the engine could convert more energy out of the combustion process at constant or low generator power demands. The study includes EGR impact on engine emissions in which both oxides of nitrogen () and carbon monoxide (CO) emissions were investigated. Exhaust gas recirculation reduced the maximum bulk mean temperature of the gas mixture, which decreased the reaction rate of emissions. When running under stoichiometric conditions, EGR seemed to decrease CO emission by reducing the dissociation rate of carbon dioxide. Increasing the intake temperature by applying hot EGR affected both the engine power and emissions. A reduction in the engine efficiency and generator power output was observed as hot EGR was applied; additionally, high intake temperatures decreased EGR’s ability to reduce .
Get full access to this article
View all available purchase options and get full access to this article.
References
Abd-Alla, G. (2002). “Using exhaust gas recirculation in internal combustion engines: A review.” Energy Convers. Manage., 43(8), 1027–1042.
Amjad, A., Saraya, R., Mahmoud, S., and Rahimia, B. (2011). “Availability analysis of -heptane and natural gas blends combustion in HCCI engines.” Energy, 36(12), 6900–6909.
Annamalai, K., and Puri, I. (2001). Advanced thermodynamics engineering, CRC Press, Boca Raton, FL.
Arcoumanis, C., Bae, C., Crookes, R., and Kinoshita, E. (2008). “The potential of di-methyl ether (DME) as an alternative fuel for compression-ignition engines: A review.” Fuel, 87(7), 1014–1030.
Atkinson, C., et al. (1999). “Numerical simulation of a two-stroke linear engine-alternator combination.”, SAE International, Warrendale, PA.
Blair, G. (1996). Design and simulation of two-stroke engines, Society of Automotive Engineers, Warrendale, PA.
Blarigan, P., Paradiso, N., and Goldsborough, S. (1998). “Homogeneous charge compression ignition with a free piston: A new approach to ideal Otto cycle performance.”, SAE International, Warrendale, PA.
Callahan, T., and Ingram, S. (1995). “Free piston engine linear generator for hybrid VEHICLES modeling study.” Center for Electro-mechanics at The Univ. of Texas at Austin, Austin, TX.
Carter, D., and Wechner, E. (2003). “The free piston power pack: Sustainable power for hybrid electric vehicles.”, SAE International, Warrendale, PA.
Charalambides, A. (2013). “Homogeneous charge compression ignition (HCCI) engines.” Chapter 4, Advances in internal combustion engines and fuel technologies, H. Kiat, ed., Intech, London, 119–148.
Chun-lan, M., Yu-sheng, Z., Yu, S., Jian, H., and Hai-ying, S. (2007). “Experimental and numerical study on emission in an HCCI engine operated with neat dimethyl ether.”, SAE International, Warrendale, PA.
Curran, H., Gaffuri, J., Pitz, W., and Westbrook, C. (2002). “A comprehensive modeling study of iso-octane oxidation.” Combust. Flame, 129(3), 253–280.
Dang, D., and Wallace, F. (1992). “Some single zone scavenging models for two-stroke engines.” Int. J. Mech. Sci., 34(8), 595–604.
Deepak, A., Kumar, S., and Kumar, A. (2011). “Effect of exhaust gas recirculation (EGR) on performance, emission, deposits and durability of a constant speed compression ignition engine.” Appl. Energy, 88(8), 2900–2907.
Duret, P., et al. (2004). “Progress in diesel HCCI combustion within the European SPACE LIGHT project.”, SAE International, Warrendale, PA.
Easley, W., Agarwal, A., and Lavoie, G. (2001). “Modeling of HCCI combustion and emissions using detailed chemistry.”, SAE International, Warrendale, PA.
Fathi, M., Saray, R., and Checkel, M. (2011). “The influence of exhaust gas recirculation (EGR) on combustion and emissions of n-heptane/natural gas fueled homogeneous charge compression ignition (HCCI) engines.” Appl. Energy, 88(12), 4719–4724.
Fischer, S., Dryer, F., and Curran, H. (2000). “The reaction kinetics of dimethyl ether. I: High-temperature pyrolysis and oxidation in flow reactors.” Int. J. Chem. Kinet., 32(12), 713–740.
Ganesan, V. (2003). Internal combustion engines, McGraw Hill, Boston.
Goodwin, D. G., Malaya, N., and Speth, R. (2017). “Cantera: An object-oriented software for chemical kinetics, thermodynamics and transport processes.” ⟨https://code.google.com/p/cantera/⟩ (Feb. 7, 2018).
Heywood, J. (1988). Internal combustion engine fundamentals, McGraw-Hill Education, New York.
Hohenberg, G. (1979). “Advanced approaches for heat transfer calculations.”, SAE International, Warrendale, PA.
Jang, J., Yang, K., Yeom, K., Bae, C., Oh, S., and Kang, K. (2009). “Improvement of DME HCCI engine performance by fuel injection strategies and EGR.” SAE Int. J. Fuels Lubr., 1(1), 1075–1083.
Jung, D., Kwon, O., and Lim, O. (2011). “Comparison of DME HCCI operating ranges for the thermal stratification and fuel stratification based on a multi-zone model.” J. Mech. Sci. Technol., 25(6), 1976–3824.
Kee, R., et al. (2005). CHEMKIN release 4.0.2, Reaction Design, San Diego.
Lapuerta, M., Hernandez, J., and Gimenez, F. (2000). “Evaluation of exhaust gas recirculation as a technique for reducing diesel engine emissions.” Proc. Inst. Mech. Eng., Part D, 214(1), 85–93.
Machrafi, H., Cavadias, S., and Guibert, P. (2008). “An experimental and numerical investigation on the influence of external gas recirculation on the HCCI autoignition process in an engine: Thermal, diluting, and chemical effects.” Combust. Flame, 155(3), 476–489.
MATLAB [Computer software]. MathWorks, Natick, MA.
Patel, A., Kong, S., and Reitz, R. (2004). “Development and validation of a reduced reaction mechanism for HCCI engine simulations.”, SAE International, Warrendale, PA.
Putrasari, Y., Jamsran, N., and Lim, O. (2017). “An investigation on the DME HCCI autoignition under EGR and boosted operation.” Fuel, 200, 447–457.
Sanli, A., Ozsezena, A., Kilicaslan, I., and Canakci, M. (2008). “The influence of engine speed and load on the heat transfer between gases and in-cylinder walls at fired and motored conditions of an IDI diesel engine.” Appl. Therm. Eng., 28(11–12), 1395–1404.
Sato, S., and Iida, N. (2003). “Analysis of DME homogeneous charge compression ignition combustion.”, SAE International, Warrendale, PA.
Wei, H., Zhu, T., Shu, G., Tan, L., and Wang, Y. (2012). “Gasoline engine exhaust gas recirculation—A review.” Appl. Energy, 99, 534–544.
Woschni, G. (1967). “A universally applicable equation for the instantaneous heat transfer coefficient in the internal combustion engine.”, SAE International, Warrendale, PA.
Xie, F., Li, X., Su, Y., Hong, W., Jiang, B., and Han, L. (2016). “Influence of air and EGR dilutions on improving performance of a high compression ratio spark-ignition engine fueled with methanol at light load.” Appl. Therm. Eng., 94, 559–567.
Xutaoand Wangyang.(2011). “Simulation of a two-stroke dimethyl-ether free piston engine operating on HCCI combustion.” Proc., 2011 Int. Conf. on Transportation, Mechanical, and Electrical Engineering, IEEE, New York, 2106–2110.
Yuan, C., Feng, H., He, Y., and Xu, J. (2016). “Combustion characteristics analysis of a free-piston engine generator coupling with dynamic and scavenging.” Energy, 102, 637–649.
Zhao, H., Peng, Z., Williams, J., and Ladommatos, N. (2001). “Understanding the effects of recycled burnt gases on the controlled autoignition (CAI) combustion in four-stroke gasoline engines.”, SAE International, Warrendale, PA.
Information & Authors
Information
Published In
Journal of Energy Engineering
Volume 144 • Issue 3 • June 2018
Copyright
©2018 American Society of Civil Engineers.
History
Received: Aug 12, 2017
Accepted: Nov 7, 2017
Published online: Mar 27, 2018
Published in print: Jun 1, 2018
Discussion open until: Aug 27, 2018
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.