TY - JOUR
TI - Experimental study on quasi-two-stage compression heat pump air conditioning system for pure electric bus
AU - Zhao Dengke
AU - Li Haijun
AU - Liu Shengyong
AU - Tian Liying
AU - Chen Gang
JN - Thermal Science
PY - 2025
VL - 29
IS - 3
SP - 1981
EP - 1989
PT - Article
AB - In response to the challenge of achieving efficient low temperature heating  performance in heat pump air conditioning systems for pure electric buses,  a quasi-two-stage compression heat pump air conditioning system  incorporating fully micro-channel technology is developed. A series of  experimental studies were conducted to investigate the influence of  different compressor speeds and fan frequencies on system performance,  resulting in corresponding performance curves. In a low temperature  environment of -10°C, the compressor exhaust temperature is maintained at  44.34°C. Concurrently, the system heat exchange capacity is enhanced by  11.3% to 47% compared to the non-supplemented air system. Moreover, at a  compressor speed of 4000 rpm, the system COP was found to be 2.72. The  implementation of variable frequency compressor speed and fan frequency in  the pure electric bus heat pump system has resulted in enhanced system  performance, leading to energy savings.