Research on control strategies for low-pressure components in integrated thermal management systems based on optimal coefficient of performance

Abstract

In pure electric vehicles (PEVs), the thermal management system's energy consumption under cooling conditions constitutes between 9.8 % and 26.9 % of the total vehicle energy expenditure. To enhance the driving range of electric vehicles, it is crucial to reduce the thermal management system's energy consumption and improve its efficiency. This research investigates the performance variations of thermal management systems under different operating conditions of low-pressure components (fans, blowers and pumps) to enhance COP (coefficient of performance) and decrease energy consumption. The study finds that while increasing the condenser air speed, HVAC (Heating, Ventilation, and Air Conditioning) air volume, and coolant flow the system's COP increase first and then decline, although the compressor's volumetric efficiency consistently improves. Especially, the research identifies a negative correlation between the evaporator's cooling capacity and the battery-side chiller's cooling capacity as HVAC air volume and coolant flow adjust. These insights are meaningful for developing effective system control strategies to boost energy efficiency and optimize cooling capacity distribution. According to analysis above, a control strategy for fans, HVAC blowers, and pumps based on optimal COP has been proposed, which demonstrates a 5.45 %–14.69 % improvement in system COP compared to traditional pressure and temperature-based control methods.

Keywords

• Pure electric vehicles
• Thermal management
• Coefficient of performance
• Control policy