Numerical simulation of indirect contact phase-change cooling system with R1234yf/R152a mixed refrigerant for battery thermal management

ABSTRACT

Refrigerant indirect contact phase-change cooling system flows refrigerant into a cold plate and utilizes the phase-change to exchange heat with the battery. However, R134a, commonly used, is being gradually restricted due to its environmental impact. A new kind of near azeotrope mixed refrigerant R1234yf/R152a (mass ratio 60.5:39.5) is proposed under environmental protection and safety. Based on the fluid-structure interaction model, the evaluation of different indirect contact phase-change cooling systems for battery thermal management (BTM) using R1234yf/R152a is investigated. After obtaining battery (150 Ah, 3.2 V LiFePO₄) parameters, heat generation power, and main test conditions through experiments, the thermal properties are numerically studied by computational fluid dynamics (CFD). At 1 C discharge rate, the temperature gradient (TG) of single battery and the maximum temperature difference (TD) among batteries are analyzed for two cases: The maximum TD among batteries of Case_b is 6.5°C lower than that of Case_a. In addition, the effect of the mixed refrigerant and traditional liquid cooling on the battery temperature is studied at different evaporation temperatures (ETs) (20°C, 25°C) and different mass flow rates (MFRs) (0.02, 0.10, and 0.18 kg/s). The results show that both the increase of inlet MFR and the reduction of inlet ET may significantly improve the battery module cooling rate. Compared with 0.02 kg/s, as the MFR increases, the temperature drop slopes to 9.56 and 11.2 at 20°C. The battery module temperature uniformity is improved with the increase of ET. Overall, the mixed refrigerant has advantages in temperature uniformity and consistency. The new mixed refrigerant plays a positive role in controlling battery temperature.

KEYWORDS:

• phase-change
• mixed refrigerant
• R1234yf/R152a
• battery thermal management
• CFD

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Natural Science Fund of China (51976014), and the Special Fund for Basic Scientific Research of Central Colleges, Chang’an University (300102222502, 300102383501, 300102383502).

Notes on contributors

Yujia Kang

Yujia Kang is currently a PhD student majored in Vehicle Operation Engineering, Chang’an University. Xi’an, China. His research interest includes battery thermal management.

Chunhua Zhang

Chunhua Zhang is currently a professor and doctoral supervisor in the School of Automobile, Chang’an University. Xi’an, China. His research interest includes new energy vehicles.

Jing Ma

Jing Ma is currently a vice-professor and doctoral supervisor in the School of Automobile, Chang’an University. Xi’an, China. Her research interest includes battery thermal management.

Ke Yang

Ke Yang is currently a PhD student majored in Vehicle New Energy and Energy Conservation Engineering, Chang’an University. Xi’an, China. His research interest includes numerical simulation.