| 摘要: |
| 热泵空调系统在满足电动汽车冬季供暖需求方面发挥了重要作用。本文采用新型低GWP值的R1234yf为制冷剂?对电动汽车热泵空调系统在－20~7 ℃环境下的低温制热性能进行了测试?对电动汽车冬季热负荷进行标定，并且与制冷剂R134a进行了对比,研究了系统制冷剂充注量、制热量、COP和排气温度的变化，同时对系统各部件火用损失进行了分析计算并根据结果
确定系统优化方向。结果表明:该系统最佳制冷剂充注量为1406g，制热量与COP在大部分工况下达到2kW与18以上，能够满足低温制热需求；R1234yf 直接替代R134a时，系统制热量与COP比R134a系统低71％与66％，系统的排气温度比R134a平均低53 ℃，系统工作更稳定可靠；热泵空调系统内冷凝器与压缩机的火用损失占系统总火用损的80％以上，是重点优化方向；增大内部冷凝器换热面积、增大风量、提高压缩机转速可显著提升R1234yf系统制热性能，使之与R134a系统的制热性能相比大约相等或者更高。 |
| 关键词: 电动汽车 热泵 R134yf 系统性能 火用分析 |
| DOI： |
| 投稿时间：2020-03-12 修订日期：2020-06-14
|
| 基金项目: |
|
| Low-temperature Heating Performance and Optimization of Electric Vehicle Heat Pump Air-conditioning System |
| Li Wanyong,Liu Yusheng,Shi Junye,Chen Jiangping,Guo Zhenjun,Wang Dajian |
| (Institute of Refrigeration and Cryogenics，Shanghai Jiao Tong University;Nanjing Xiezhong Auto-airconditioner(group) Co.,Ltd.) |
| Abstract: |
| Heat pump air-conditioning systems play an important role in meeting the winter heating needs of electric vehicles. In this study, the new refrigerant R1234yf, which has a low GWP value, was used for the working medium. The low-temperature heating performance of the electric vehicle heat pump air-conditioning system was tested at ?20 ℃ to 7 ℃. The winter heat load of the electric vehicle was calibrated. The refrigerant charge amount, heating performance, COP, and discharge temperature of the system were studied and compared with those of refrigerant R134a. Exergy loss of system components was analyzed, and the system was also optimized. The results show that the optimal refrigerant charge amount of the system was 1551 g, and the heating capacity and COP reached greater than 2 kW and 1.8, respectively, under most working conditions, which could meet the needs of heating at low temperatures. When directly substituted, the heating capacity and COP of the system were 7.1% and 6.6% lower than that of the R134a system. The discharge temperature of the R1234yf heat pump system is 5.3 ℃lower than that of R134a, which could make the system more stable and reliable. The exergy loss of the inner condenser and compressor accounts for more than 80% of the total exergy loss of the system, which is the key optimization parameter for heat pump air conditioning. Increasing the heat transfer area of the inner condenser, increasing the air volume, and improving the compressor speed can significantly improve the heating performance of the system, making it basically equal to or even better than the R134a system. |
| Key words: electric vehicle heat pump R1234yf system performance exengy loss analysis |
