电动车辆热管理系统中CO₂工质替代方案对续航里程的影响

To address the phase-out of traditional refrigerants in electric vehicle thermal management systems and the concern of winter driving range anxiety, an evaluation of energy efficiency optimization and driving range impact is conducted on a thermal management system that uses the excellent heating capabilities of the natural refrigerant carbon dioxide (R744). An experimental platform for a transcritical R744 thermal management system is set up, and a detailed dynamic whole-vehicle thermal system model incorporating R134a and R744 is developed using GT-suite. This model encompasses the thermal management system, battery thermal-electric system, power system, cabin thermal model, and controller to evaluate energy consumption and driving performance under real-world driving conditions. Experimental and simulation findings reveal that the inlet coolant temperature of the battery cooler has minimal impact on the optimal exhaust pressure, while increasing the coolant flow rate raises the optimal pressure by approximately 0. 2-0. 3 MPa, with ambient temperature significantly influencing the optimal exhaust pressure. Furthermore, a thermal management energy consumption factor is defined to quantitatively evaluate the system's energy consumption impact on overall vehicle energy usage. Comparative analysis reveals that at 40°C, the energy consumption factor of the R744 system is 0. 066 higher than that of R134a, leading to a 7. 02% reduction in driving range. Conversely, at - 25 °C, the energy consumption factor of R744 is 0. 27 lower than that of R134a, resulting in a 44. 52 % increase in driving range. Considering factors such as average annual driving range, operating costs, and environmental considerations, the R744 system proves more advantageous in cold, cool, and mild climate zones, while R134a is better suited for hotter and temperate regions.