This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A New Turboexpansion Concept in a Twin-Charged Engine System
Technical Paper
2014-01-2596
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Engines equipped with pressure charging systems are more prone to knock partly due the increased intake temperature. Meanwhile, turbocharged engines when operating at high engine speeds and loads cannot fully utilize the exhaust energy as the wastegate is opened to prevent overboost. The turboexpansion concept thus is conceived to reduce the intake temperature by utilizing some otherwise unexploited exhaust energy.
This concept can be applied to any turbocharged engines equipped with both a compressor and a turbine-like expander on the intake loop. The turbocharging system is designed to achieve maximum utilization of the exhaust energy, from which the intake charge is over-boosted. After the intercooler, the turbine-like expander expands the over-compressed intake charge to the required plenum pressure and reduces its temperature whilst recovering some energy through the connection to the crankshaft. It is anticipated that such a concept has benefits for knock resistance and energy recovery despite suffering higher pumping losses.
This paper, for the first time, will investigate the net fuel efficiency benefit from this concept using a super-turbo twin-charger 1-D simulation model. By the operation of a switch between compressor and expander mode, the supercharger could provide boost at low engine speed whilst behaving like a turbine presenting an indirect means to recover exhaust gas energy at high engine speed and meanwhile reducing the intake temperature. The results showed that the BSFC improvement depended on the efficiency of the supercharger as an expander.
Recommended Content
Authors
Topic
Citation
Hu, B., Copeland, C., Brace, C., Akehurst, S. et al., "A New Turboexpansion Concept in a Twin-Charged Engine System," SAE Technical Paper 2014-01-2596, 2014, https://doi.org/10.4271/2014-01-2596.Also In
References
- Turner , J. , Popplewell , A. , Patel , R. , Johnson , T. et al. Ultra Boost for Economy: Extending the Limits of Extreme Engine Downsizing SAE Int. J. Engines 7 1 387 417 2014 10.4271/2014-01-1185
- Turner , J. , Pearson , R. , and Milovanovic , N. , 12 Reducing the Octane Appetite of Pressure-Charged Gasoline Engines using Charge Air Conditioning Systems 2006 JSAE Annual Congress Japan May 2006
- Turner , J. , Pearson , R. , Bassett , M. , Blundell , D. et al. The Turboexpansion Concept - Initial Dynamometer Results SAE Technical Paper 2005-01-1853 2005 10.4271/2005-01-1853
- Whelan , C. , Richards , R. , Spence , S. , Young , A. , Design and development of a turbo-expander for charge air cooling ImechE 9 th international Conference on Turbochargers and Turbocharging UK May 19-20 2010
- Romagnoli , A. , Wan-Salim , W. , Gurunathan , B. , Martinez-Botas , R. et al. Assessment of supercharging boosting component for heavily downsized gasoline engines ImechE 11th international Conference on Turbochargers and Turbocharging UK May 13-14 2014
- Eichhorn , R. , Boot , M. , and Luijten , C. , Waste Energy Driven Air Conditioning System (WEDACS) SAE Int. J. Engines 2 2 477 492 2009 10.4271/2009-24-0063
- Rose , A. , Akehurst S. , and Brace , C. , Investigation into the trade-off between the part-load fuel efficiency and the transient response for a highly boosted downsized gasoline engine with a supercharger driven through a continuously variable transmission Proc. of IMECHE, Part D: Journal of Auto. Eng 2013 10.1177/0954407013492932
- Douaud , A. and Eyzat , P. , Four-Octane-Number Method for Predicting the Anti-Knock Behavior of Fuels and Engines SAE Technical Paper 780080 1978 10.4271/780080
- GT-SUITE manual, Version 7.4.0 Build 1