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Potentials of Electrical Assist and Variable Geometry Turbocharging System for Heavy-Duty Diesel Engine Downsizing
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 28, 2017 by SAE International in United States
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Diesel engine downsizing aimed at reducing fuel consumption while meeting stringent exhaust emissions regulations is currently in high demand. The boost system architecture plays an essential role in providing adequate air flow rate for diesel fuel combustion while avoiding impaired transient response of the downsized engine. Electric Turbocharger Assist (ETA) technology integrates an electric motor/generator with the turbocharger to provide electrical power to assist compressor work or to electrically recover excess turbine power. Additionally, a variable geometry turbine (VGT) is able to bring an extra degree of freedom for the boost system optimization. The electrically-assisted turbocharger, coupled with VGT, provides an illuminating opportunity to increase the diesel engine power density and enhance the downsized engine transient response. This paper assesses the potential benefits of the electrically-assisted turbocharger with VGT to enable heavy-duty diesel engine downsizing. A 1D engine simulation model of the Caterpillar 7.1L 6-cylinder diesel engine has been developed and validated against engine test data taken with ETA device fitted. Both steady state and transient engine performance are evaluated with different electric power levels, motor response time and VGT vane positions. The ETA technology gives transient response benefits over a range of transient events, but with diminishing returns at the higher levels of ETA power. Better transient response and fuel consumption could be achieved by combining ETA device with VGT versus a standard fixed turbine. The importance of ETA control with fast response time during transient maneuver is highlighted. This study also demonstrates the engine speed drop is less significantly affected than recovery time over block load test by employing ETA technology. This potential limit of the requirement to have sufficient initial excess boost for downsized engine could be addressed by controlling the VGT vane position. Finally, the capability of this optimized boosting system to enable downsizing from 9.3L to 7.1L is demonstrated.
CitationXue, X. and Rutledge, J., "Potentials of Electrical Assist and Variable Geometry Turbocharging System for Heavy-Duty Diesel Engine Downsizing," SAE Technical Paper 2017-01-1035, 2017, https://doi.org/10.4271/2017-01-1035.
- Salehi, R., Martz, J., Stefanopoulou, A., Hansen, T. et al., "Comparison of High- and Low-Pressure Electric Supercharging of a HDD Engine: Steady State and Dynamic Air-Path Considerations," SAE Technical Paper 2016-01-1035, 2016, doi:10.4271/2016-01-1035.
- Saulnier, S. and Guilain, S., "Computational Study of Diesel Engine Downsizing Using Two-StageTurbocharging," SAE Technical Paper 2004-01-0929, 2004, doi:10.4271/2004-01-0929.
- Eilts, P., "Investigation of Engine Processes with Extreme Pressures and Turbocompounding," SAE Technical Paper 2016-01-0567, 2016, doi:10.4271/2016-01-0567.
- Keidel, S., Wetzel, P., Biller, B., Bevan, K. et al., "Diesel Engine Fuel Economy Improvement Enabled by Supercharging and Downspeeding," SAE Int. J. Commer. Veh. 5(2):483-493, 2012, doi:10.4271/2012-01-1941.
- Uchida, H., “Trend of turbocharger technologies,” R&D Review of Toyota CRDL, Vol. 41, 2006, No. 3, 1-8.
- Costall, A., Ivanov R., and Langley T.. "Electric turbo assist: efficient rapid boost for heavy duty diesel engines," In Proceedings of the Conference on Thermo and Fluid Dynamic Processes in Direct Injection Engines, pp. 1-18. 2012.
- Buchi, A., “Internal Combustion Engine,” US Patent 2036989, 1936.
- Bailey, M., “Electrically-assisted turbocharger development for performance and emissions,” No. CONF-200008-35, Oak Ridge National Lab., Oak Ridge, TN (US), 2000.
- Kruiswyk, R., “An Engine System Approach to Exhaust Waste Heat Recovery,” Final Report, US Department of Energy Contract DE-FC26-05NT42423, 2010.
- Arnold, S., Balis, C., Bathelet, P., Poix, E., Samad, T., Hampson, G and Shahed, S.M. (2005a) “Garrett Electric Boosting Systems (EBS) Program,” Federal Grant DE-FC05-00OR22809, Final Report, Honeywell Turbo Technologies, 22 June, 2005.
- Watkins S. and Winward E., “Modeling and control of an ultrahigh-speed switched reluctance machine,” 8th IET International Conference on Power Electronics Machines and Drives, 19-21 April, Glasgow, Scotland, 2016.
- Winward E., et al., “Performance testing of an electrically assisted turbocharger on a heavy duty diesel engine,” 12th International Conference on Turbochargers and Turbocharging, 2016.
- Terdich, N. and Martinez-Botas, R., "Experimental Efficiency Characterization of an Electrically Assisted Turbocharger," SAE Technical Paper 2013-24-0122, 2013, doi:10.4271/2013-24-0122.
- Fluga, E., "Modeling of the Complete Vehicle Powertrain Using ENTERPRISE," SAE Technical Paper 931179, 1993, doi:10.4271/931179.
- Williams, D., Koci, C., and Fiveland, S., "Compression Ignition 6-Stroke Cycle Investigations," SAE Int. J. Engines 7(2):656-672, 2014, doi:10.4271/2014-01-1246.
- Ernst, Benedikt, Kammeyer Jasper, and Seume Joerg R.. "Improved Map Scaling Methods for Small Turbocharger Compressors." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition, pp. 733-744. American Society of Mechanical Engineers, 2011.
- Zhang, Qingning, Pennycott Andrew, and Brace Chris J.. "A review of parallel and series turbocharging for the diesel engine," Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 227, no. 12 (2013): 1723-1733, 2013.
- Smith, H. W., and E. J. Davison. "Design of industrial regulators. Integral feedback and feed forward control." Electrical Engineers, Proceedings of the Institution of 119, no. 8 (1972): 1210-1216, 1972.
- Zhao, D., Winward, E., Yang, Z., Rutledge, J. et al., "Control-Oriented Dynamics Analysis for Electrified Turbocharged Diesel Engines," SAE Technical Paper 2016-01-0617, 2016, doi:10.4271/2016-01-0617.
- Zhao, D., Winward, E., Yang, Z. et al., "Decoupling control of electrified turbocharged diesel engines." In American Control Conference (ACC), 2016, pp. 4207-4212. American Automatic Control Council (AACC), 2016.