Abstract
High power density, stoichiometric, turbocharged, directly injected engines with water injection and a three-way catalytic converter after treatment have been proposed as one of the most promising H2ICE [1]. These throttle-controlled engines have top brake efficiencies exceeding 40%, but large penalties in efficiency reducing the load with 1 bar BMEP values approaching 10%. Recovery of the large amount of fuel energy lost in the coolant especially at low loads as well as the fuel energy lost in the exhaust that is significant at high loads and speeds may push not only the top brake efficiencies to exceed the 45% mark, but also to dramatically increase the low load efficiency compromised by the throttling. in this paper, recovery of the waste heat from the exhaust gases and the coolant in a H2ICE is performed with Organic Rankine Cycles (ORC). the engine without ORC has a maximum efficiency of 42% and an average efficiency over the map points of 32.7%. with the exhaust ORC, neglecting the possible back pressure increase due to the heat exchanger downstream of the catalytic converter the maximum efficiency increases to 45.6%, and the average efficiency rises to 35.3%. with the coolant ORC, neglecting the reduced mechanical efficiency for the coolant back pressure increment, the maximum efficiency increases to 43.4% and the average efficiency increases to 34.6%. Finally, combining the two ORC with same assumptions, the maximum efficiency increases to 46.9% and the average efficiency to 38%. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Recommended Citation
A. Boretti, "Stoichiometric H2ICE with Water Injection and Exhaust and Coolant Heat Recovery through Organic Rankine Cycles," International Journal of Hydrogen Energy, vol. 36, no. 19, pp. 12591 - 12600, Elsevier, Sep 2011.
The definitive version is available at https://doi.org/10.1016/j.ijhydene.2011.06.124
Department(s)
Mechanical and Aerospace Engineering
Keywords and Phrases
Coolant energy recovery; Exhaust energy recovery; Hydrogen internal combustion engines; Organic rankine cycles
International Standard Serial Number (ISSN)
0360-3199
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Elsevier, All rights reserved.
Publication Date
01 Sep 2011
