Study on Mixed Working Fluids with Different Compositions in Organic Rankine Cycle (ORC) Systems for Vehicle Diesel Engines

Kai Yang; Hongguang Zhang; Enhua Wang; Songsong Song; Chen Bei; Ying Chang; Hongjin Wang; Baofeng Yao

doi:10.3390/e16094769

Entropy (Aug 2014)

Study on Mixed Working Fluids with Different Compositions in Organic Rankine Cycle (ORC) Systems for Vehicle Diesel Engines

Kai Yang,
Hongguang Zhang,
Enhua Wang,
Songsong Song,
Chen Bei,
Ying Chang,
Hongjin Wang,
Baofeng Yao

Affiliations

Kai Yang: College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan No.100, Beijing 100124, China
Hongguang Zhang: College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan No.100, Beijing 100124, China
Enhua Wang: College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan No.100, Beijing 100124, China
Songsong Song: College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan No.100, Beijing 100124, China
Chen Bei: College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan No.100, Beijing 100124, China
Ying Chang: College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan No.100, Beijing 100124, China
Hongjin Wang: College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan No.100, Beijing 100124, China
Baofeng Yao: College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan No.100, Beijing 100124, China

DOI: https://doi.org/10.3390/e16094769
Journal volume & issue: Vol. 16, no. 9
pp. 4769 – 4787

Abstract

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One way to increase the thermal efficiency of vehicle diesel engines is to recover waste heat by using an organic Rankine cycle (ORC) system. Tests were conducted to study the running performances of diesel engines in the whole operating range. The law of variation of the exhaust energy rate under various engine operating conditions was also analyzed. A diesel engine-ORC combined system was designed, and relevant evaluation indexes proposed. The variation of the running performances of the combined system under various engine operating conditions was investigated. R245fa and R152a were selected as the components of the mixed working fluid. Thereafter, six kinds of mixed working fluids with different compositions were presented. The effects of mixed working fluids with different compositions on the running performances of the combined system were revealed. Results show that the running performances of the combined system can be improved effectively when mass fraction R152a in the mixed working fluid is high and the engine operates with high power. For the mixed working fluid M1 (R245fa/R152a, 0.1/0.9, by mass fraction), the net power output of the combined system reaches the maximum of 34.61 kW. Output energy density of working fluid (OEDWF), waste heat recovery efficiency (WHRE), and engine thermal efficiency increasing ratio (ETEIR) all reach their maximum values at 42.7 kJ/kg, 10.90%, and 11.29%, respectively.

Published in Entropy

ISSN: 1099-4300 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Astronomy: Astrophysics; Science: Physics
Website: http://www.mdpi.com/journal/entropy

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