Enhancing heat dissipation to improve efficiency of two-stage electric air compressor for fuel cell vehicle. (1st January 2022)

• Record Type: Journal Article
• Authors: Hu, Donghai; Liu, Jie; Yi, Fengyan; Yang, Qingqing; Zhou, Jiaming
• Is Part Of: Energy conversion and management. Volume 251(2022)
• Publication Date: 2022-01-01
• Subjects: Two-stage electric air compressor -- Proton exchange membrane fuel cell -- Temperature rise characteristic -- Heat dissipating capacity; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2021.115007
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: The temperature rise law of fuel cell two-stage electric air compressor during gas compression is studied. It is analyzed that the fuel cell two-stage electric air compressor has a larger gas temperature rise, which brings extra power consumption. The mathematical relationship between compression work and calorific value of fuel cell two-stage electric air compressor is derived. It is proposed that increasing heat dissipation of shell can improve efficiency, and the feasibility of this method is verified by simulation. Abstract: The electric air compressor is the most energy-consuming auxiliary component in the PEMFC (Proton Exchange Membrane Fuel Cell), and its power consumption accounts for more than 80% of the PEMFC parasitic power. Improving the efficiency of electric air compressor is of great significance to energy saving of the PEMFC. In this study, the numerical equation of the internal flow channel of the TSEAC (Two-stage Electric Air Compressor) was established. The validity of the numerical equation was verified by the experimental study. It is found that the heat generated by the electric air compressor for the PEMFC is 2–4 times higher than that of the turbocharger for a traditional diesel engine. Besides, the temperature-rising characteristics of gas in the inner flow passage of the TSEAC are analyzed. Under its normal working conditions, the temperature rise of gas passing through impeller and diffuser reaches the maximum of 33.97 K and 48.95 K, respectively. Higher temperatures cause gas to be heated and expand more, thus increasing the compression power of compressed gas consumed, and the efficiency of the TSEAC is reduced. The theoretical compression power of the TSEAC with cooling compression process is calculated. It is concluded that shell cooling can reduce the export of first and second level compression stress and the second level compression inlet temperature. Under constant inlet pressure and temperature, shell cooling can reduce the internal power consumption of the TSEAC. In order to verify the feasibility of this study, the thermal conductivity of the TSEAC shell was increased from 273 W / ( m · K ) to 397 W / ( m · K ) and 524 W / ( m · K ), the outlet temperature was decreased by 7.5 K and 12 K, and the maximum efficiency was increased by 1.3 % and 2.4 %, respectively.