Title: Analysis of an air hybrid engine concept with an energy recovery valve

Authors: H. Zhao, C. Psanis, T. Ma

Addresses: Centre for Advanced Powertrain and Fuels, School of Engineering and Design, Brunel University, West London UB8 3PH, UK. ' Centre for Advanced Powertrain and Fuels, School of Engineering and Design, Brunel University, West London UB8 3PH, UK. ' Centre for Advanced Powertrain and Fuels, School of Engineering and Design, Brunel University, West London UB8 3PH, UK

Abstract: In this paper, an air hybrid engine with an Energy Recovery Valve (ERV) will be described and analysed. The investigation started with systematic studies on the effect of various ERV valve opening and closing events on the performance of Compressor Mode (CM) and Expander Mode (EM) operations. After having defined the optimal valve timings for CM and EM operations over a range of engine speeds, the effect of other operating parameters on the performance of the air hybrid engine was examined. It has been found that the ERV concept is characterised with constant and predictable braking torque, independent of the State of Charge (SOC) of the energy storage tank. The presence of the buffer chamber volume limits the maximum airtank pressure to 15-18 bar and actual braking mean effective pressure to 2-4 bar.

Keywords: air hybrid engines; compressor mode; energy recovery valves; expander mode; valve timings; braking torque; vehicle design; exhaust emissions; greenhouse gases; CO2; carbon emissions; vehicle powertrains.

DOI: 10.1504/IJVD.2011.038072

International Journal of Vehicle Design, 2011 Vol.55 No.1, pp.49 - 75

Received: 21 May 2010
Accepted: 05 Jun 2010

Published online: 14 Jan 2011 *

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