光伏太阳能热泵/环形热管复合热水系统性能模拟

摘要

A numerical model for photovoltaic solar assisted heat pump/loop heat pipe (PV-SAHP/LHP) hybrid water heater system was established. The performances of independent heat pump mode (HP) and loop heat pipe-heat pump switching mode (LHP-HP) were simulated. Based on the least power consumption, the effects of various solar radiation and ambient temperature on optimal switch ofLHP-HP mode were analyzed, and the all-year-round operation status was also calculated. The results show that when heating 150 L tank from 15℃ to 50℃ in typical spring and autumn sunny weather, the average thermal efficiency and electrical efficiency ofLHP-HP mode are respectively 37.00％ and 6.88％ lower than that of independent HP mode, while using theLHP-HP mode saves up to 40.60％ power consumption. With the increase of solar radiation and ambient temperature, the optimal switching water temperature ofLHP-HP increases and the compressor power consumption decreases. On sunny days from March to November,LHP-HP mode should be in priority-of-use mode to save electricity. HP mode should be used in winter or in low-solar radiation and ambient temperature conditions.%针对光伏太阳能热泵/环形热管(PVSA-HP/LHP)复合热水系统建立数学模型,对该系统在热泵(HP)模式独立运行、环形热管-热泵(LHP-HP)复合模式运行下的性能进行对比模拟.基于压缩机耗能最少的原则,分析太阳辐照强度和环境温度的变化对LHP-HP模式下合理切换时刻的影响,并以此为基准计算系统在复合模式下全年各月份的运行状况.研究结果表明:在春、秋季典型晴天工况下,将150 L水从15℃加热到50℃的运行过程中,LHP-HP模式的平均热效率和电效率分别比HP模式低37.00％和6.88％,但节约40.60％的电能;随着太阳辐照强度的增强以及环境温度升高,LHP-HP模式下切换时刻的冷凝水温升高,压缩机所消耗的电能减少.在3～11月份晴天工况下,应尽量优先采用LHP-HP复合模式运行以节约电能;在冬季或太阳辐照较低时,则采用HP模式独立运行.