相变蓄热型空气源热泵系统蓄、释热特性与供暖节能运行温度条件的研究

Study on the thermal energy storage and release characteristics and the energy-saving operating temperature condition of PCM based ASHP system

文章通过对典型城市最冷月的日逐时室外空气的平均温度进行分析,并结合空气源热泵的运行特性、建筑供暖负荷规律和人们的用能规律,提出了一种相变蓄热型空气源热泵系统,实现了通过日蓄、夜释的方式弥补低温时段空气源热泵供热能力不足的目的。文章设计了新型翅片管式相变蓄热器,开展了相变蓄热型空气源热泵系统蓄、释热特性实验。实验结果表明:翅片管式相变蓄热器蓄热时,相变蓄热材料温度分布均匀,空气源热泵的冷凝温度与相变蓄热材料之间的温度差为1.1℃,这有利于降低空气源热泵冷凝温度、提高空气源热泵性能系数;翅片管式相变蓄热器释热时,相变蓄热器入口水温对释热速度具有重要影响。同时,对相变蓄热型空气源热泵系统的蓄热能效进行分析,得到了相变蓄热型空气源热泵系统供暖节能运行温度条件。

Based on the analysis of the average hourly ambient temperature variation of 3 typical cities in the coldest month,the operation characteristics of air source heat pump(ASHP),the law of building’s heating load and people’s energy consumption,a PCM based ASHP system with phase change thermal storage was presented to make up for the insufficient heating supply capacity of ASHP in low temperature period by daily storing and night releasing.A fin-tube phase change thermal storage heat exchanger was designed,and experimental study on the thermal energy storage and release characteristics of the PCM based ASHP system was carried out.Results show that the temperature of PCM in the thermal storage heat exchanger is uniform in thermal energy storage process.The average difference between the PCM’s temperature and condensation temperature is only 1.1℃,which is beneficial to the ASHP’s coefficient of performance(COP)by reducing the condensation temperature of ASHP.In the process of thermal energy release process,inlet water temperature of the thermal storage heat exchanger has great influence on heat release rate.By analyzing the COP of the PCM based ASHP system operated in thermal energy storage and release modes,the energy-saving operating temperature condition for the PCM based ASHP is obtained.