两级压缩空气源热泵热水器实验研究

Experiment on Two-stage Compression Air-source Heat Pump Water Heater

空气源热泵热水器是一种消耗少量电能驱动热泵从空气中吸取热量加热热水的装置,但普通单级空气源热泵热水器在低温环境下运行中存在压缩比过大、制热量不足和制热效率低等问题。采用两级压缩制冷循环用于空气源热泵热水器,则可以解决空气源热泵热水器低温适应性的问题。设计出具有单双级两种循环模式的两级压缩空气源热泵热水器系统,并搭建了实验台进行了实验研究。实验表明:低温环境下,双级压缩循环压缩比低于普通单级压缩循环压缩比;系统制热量始终大于单级压缩循环制热量;系统能效比(COP)在-20℃环境温度下依然能够保持在1.5左右。

The two-stage compression refrigeration cycle was adopted in air-source heat pumps（ASHP） to improve the feasibility of ASHP at low ambient temperature. An air-source heat pump water heater with both modes of single-stage and two-stage compression cycles was designed and a test rig was built up. The experimental results show that the compression ratio in the two-stage compression cycle mode was smaller than that in the single-stage compression cycle mode while the heating ability of the pump with the two-stage compression cycle mode was higher at low ambient temperature. The COP of the two-stage compression system could reach about 1.5 when the ambient temperature was -20°C.