Abstract: With the implementation of the Kigali Amendment to the Montreal Protocol, the automotive air conditioning industry is facing the challenge of accelerating the transition from high global warming potential (GWP) refrigerants to low-GWP alternatives. R134a (GWP=1 300), as the current mainstream refrigerant, will be prohibited from use in air conditioning systems of M1- category vehicles for new applications for announcement in China starting from July 2029. R1234yf, with its extremely low GWP (<1), has emerged as the most promising substitute. Plug-in hybrid electric vehicle (PHEV), characterized by complex powertrain systems and diverse thermal management requirements, imposes higher demands on air conditioning performance. This paper establishes a one-dimensional model of a PHEV air conditioning system based on the AMESim platform, systematically comparing the cooling performance, coefficient of performance (COP), energy consumption, and cooling effects of R134a and R1234yf under various operating conditions. Additionally, the improvement effects of incorporating an internal heat exchanger (IHX) and optimizing the thermal expansion valve on R1234yf system performance are analyzed, providing a theoretical basis for the selection of environmentally friendly refrigerants and engineering optimization of PHEV air conditioning systems.

Key words: plug-in hybrid electric vehicle; air conditioning system; R134a; R1234yf; AMESim

摘要： 随着《基加利修正案》的实施，汽车空调行业正面临从高全球变暖潜能值（GWP）制 冷剂向低 GWP 制冷剂加速转型的挑战。R134a（GWP=1 300）作为当前主流制冷剂，将于 2029 年 7 月起被禁止用于国内新申请公告的 M1 类车辆空调系统，R1234yf 以其极低 GWP（<1） 成为最具潜力的替代方案。插电式混合动力汽车（PHEV）动力系统复杂、热管理需求多样， 对空调性能要求更高。文章基于 AMESim 平台搭建 PHEV 空调系统一维模型，系统对比 R134a 与 R1234yf 在不同工况下的制冷性能、能效比（COP）、能耗及降温效果，并分析增设内部热 交换器（IHX）、优化热力膨胀阀等改进措施对 R1234yf 性能的提升作用，为 PHEV 空调系统 环保制冷剂选型与工程优化提供理论依据。

关键词: 插电式混合动力汽车；空调系统；R134a；R1234yf；AMESim