Low-temperature Heating Performance and Optimization of Electric Vehicle Heat Pump Air-conditioning System
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-co...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | zho |
| Published: |
Journal of Refrigeration Magazines Agency Co., Ltd.
2020-01-01
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| Series: | Zhileng xuebao |
| Subjects: | |
| Online Access: | http://www.zhilengxuebao.com/thesisDetails#10.3969/j.issn.0253-4339.2020.06.031 |
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| Summary: | 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. |
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| ISSN: | 0253-4339 |