为评估自然工质CO₂与R290在热管理系统中替代R134a的转型潜力，基于仿真平台搭建了涵盖乘员舱、电池及动力系统的整车高精度动态模型，并据此系统评估了其在CLTC（China Light-Duty Vehicle Test Cycle）下的热管理性能。结果表明：电机功率与车速变化之间呈现显著相关性，而热管理系统的功率较之更稳定。在制冷条件下，R290相较于CO₂具有能效优势，热管理能耗系数（Thermal Management Energy Consumption Factor, TMEF）更小。但极端高温40℃和45℃时，R290系统的TMEF高于CO₂系统。在制热工况下，CO₂热管理系统具有突出的能效优势。0 ℃和7 ℃环境温度时，3个系统能效基本持平。此外，当环境温度在-10℃以下时，R290系统相较R134a系统的性能表现更优。随着环境温度降低，CO₂系统相较于R290系统的优势不断提升。因此，CO₂在严寒地区存在性能优势，而R290更适用于温和炎热地区。这些分析为电动汽车低碳高效的热管理工质替代提供了理论依据。

To evaluate the potential of natural refrigerants CO₂ and R290 for replacing R134a in thermal management systems, a high-precision dynamic vehicle-level model encompassing the cabin, battery, and powertrain was developed on a simulation platform. The thermal management performance of systems using these refrigerants was systematically evaluated under the China Light-Duty Vehicle Test Cycle (CLTC). During dynamic operation, the motor power was significantly correlated with speed variations, whereas the power of the TMS was more stable. In cooling conditions, R290 had an energy efficiency advantage over CO₂, with a smaller thermal management energy consumption factor (TMEF). However, at extreme high temperatures of 40°C and 45°C, the TMEF of the R290 system exceeded that of the CO₂ system. In heating conditions, CO₂ TMS has an outstanding energy efficiency advantage. At ambient temperatures of 0°C and 7°C, the TMEF of all three systems were essentially equivalent. When the ambient temperature dropped below -10°C, the R290 system performed better than the R134a system. Besides, as the ambient temperature decreased, the advantage of the CO₂ system over the R290 system continued to increase. Therefore, CO₂ has a performance advantage in cold or extremely hot regions, while R290 is more suitable for mildly hot regions. These analyses provide important guidance for low-carbon and efficient refrigerant substitution in thermal management for electric vehicles.