Simulation analysis of BOP thermal management system for hydrogen fuel cell bus

Hydrogen fuel cell bus has been rapidly developed. As an important part of the hydrogen fuel cell system, its BOP (Balance of plant) mainly includes air compressor, controller, and intercooler. In practical applications, the BOP thermal management system generally includes separated cooling circuits. This study proposes an integrated BOP thermal management system, in which the air compressor, the controller and the intercooler share the same cooling circuit. A 1-D numerical model is built in this paper. On the basis of the model, the 13 possible layout schemes of cooling circuit are investigated. Additionally, the BOP temperature variation characteristics under the UDDS (Urban Dynamometer Driving Schedule) condition are also analyzed. The results indicate that not all layouts of integrated scheme can meet the cooling requirements. To meet cooling requirements of the whole BOP, the coolant should pass through the intercooler first in the serial schemes. As for the parallel schemes, the air compressor should be in a single branch, and the controller and the intercooler should be in series successively at another branch. Under the same total flow rate, the average temperature of BOP in the series scheme can be lower than that in parallel scheme by 8 %. In the three components, the intercooler is most affected by the stack power. This study provides reference for the design of the BOP thermal management system.