Performance Investigation of a Cabin Thermal Management System for Electric Vehicles Based on R290 Refrigerant

Abstract

Electric vehicle (EV) thermal management systems (TMSs) face a critical challenge in adopting environmentally friendly refrigerants, essential for adaptability, thermal safety, driving range optimization, and passenger comfort across wide temperature ranges. This study investigates the use of R290, a low-cost and environmentally friendly refrigerant, in a secondary-loop-based TMS. A system test bench was established to validate the system performance experimentally, and a comparison was made with the system using R134a. The experimental results show that the R290 charge amount is approximately 50% of that of R134a. Under low-temperature heating condition (0°C), R290 demonstrates significant performance advantages, with heating capacity and coefficient of performance (COP) increasing by up to 67.6% and 36%, respectively, compared to R134a. At extremely low temperatures (−20°C), R290 achieves a COP of 1.24, further showcasing its superior heating performance. Under high-temperature cooling conditions (35 and 43°C), R290 exhibits slightly lower cooling capacity compared to R134a; however, its performance remains sufficient to meet the operational requirements of a TMS. In summary, the proposed TMS using R290 as the refrigerant demonstrates excellent performance and promising potential for application in EVs across a wide range of operating conditions.