Optimizing the influence of refrigerant superheat on the cooperative thermal management system performance for the vehicle cabin and battery

Abstract

The refrigerant superheat significantly impacts on the energy consumption of the vehicle cabin and battery collaborative thermal management system. The study investigates the problem using a genetic algorithm. Firstly, the model of collaborative thermal system is established and verified. Then, the coefficient of performance (COP) maximization is taken as the optimization target during steady-state conditions. The results show that the optimal refrigerant superheat at the evaporator outlet (SEva) is very low for different heat dissipation of the battery (HBat) as well as ambient temperature, while the optimal refrigerant superheat at the chiller outlet (SChi) is affected by the HBat as well as ambient temperature. Finally, according to conclusions under the steady state, the SEva is set to 1 K and taking the energy consumption (EC) as the response under transient condition, the SChi is determined. The results indicate that when the SChi is decided by single-point optimization, the optimal SChi is 18 K, and the EC is 1490 kJ, which is 2.3 % energy saving compared to the basic condition. When the SChi is decided by two-point optimization, the optimal two superheats are 12 K and 37 K and the EC is 1460 kJ, which is 4.3 % energy saving compared to the basic condition.