This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Fuel-Economy Performance Analysis with Exhaust Heat Recovery System on Gasoline Engine
Journal Article
03-15-06-0045
ISSN: 1946-3936, e-ISSN: 1946-3944
Sector:
Topic:
Citation:
Kumar, V., Dadam, S., Zhu, D., and Mehring, J., "Fuel-Economy Performance Analysis with Exhaust Heat Recovery System on Gasoline Engine," SAE Int. J. Engines 15(6):825-847, 2022, https://doi.org/10.4271/03-15-06-0045.
Language:
English
Abstract:
As the electrification and connectivity technologies penetrate the market, the
opportunities for intelligent thermal management of the vehicles become more
salient. When an exhaust gas heat recovery (EGHR) system is used to recover
waste heat from gasoline engine exhaust, the thermal parameters of the exhaust
gas vary greatly, and these influence the performance of the heat exchanger (HE)
system. To improve the recovery of exhaust waste heat and its conversion to
faster coolant warm-up and cabin heating performance effectively, the heat
transfer evaluation and optimal performance analysis are conducted on different
EGHR system designs with different exhaust thermal parameters. This study aims
at analyzing the fuel economy benefit with state-of-the-art HE designs in the
automotive industry for exhaust gas-to-oil and exhaust gas-to-coolant heat
transfer. Both physical testing and virtual simulation helped us develop a
method to take advantage of the exhaust gas heat. The test result indicates that
with the integration of the exhaust gas-to-coolant and exhaust gas-to-oil HEs,
the gasoline engine makes a 0.5% and 0.8% fuel efficiency improvement,
respectively. More specifically, the Worldwide harmonized Light vehicles Test
Cycles (WLTC) fuel consumption on the 1.0L engine can be reduced by 0.5% with
the integration of exhaust gas to the coolant HE, which has a smart bypass
control strategy upstream of the oil cooler. Also the implementation of exhaust
gas-to-oil HEs leads to a WLTC fuel consumption reduction of 0.8%. HE design
with bypass valve and valve-controlled oil cooler from the experiments proved to
be the most efficient HE design among the four investigated designs. The
proposed simulation-based performance and engine dynamometer (dyno) evaluation
shed light on the importance of selecting bypass valve and valve-controlled oil
cooler HEs and design-related improvements in fuel economy for practical
applications in building intelligent thermal management for vehicles.