Abstract:

In view of the fact that, during heating, the traditional air source heat pump when placed outdoors is very prone to frost, a new type of direct expansion solar / air-assisted heat pump was proposed, which can absorb solar energy as well as air energy at the same time. Due to this creation, namely, the combination of solar collector and heat pump evaporator, the frost issue can be effectively alleviated. To verify its performance, a new direct expansion solar / air-assisted heat pump system and an air source heat pump system were established. From Feb. 26th to Mar. 2nd, a 5-day practical test on the floor radiant heating of rural buildings was conducted in a village of Handan City. Then, based on the results, we conducted comparative analysis on the two systems’ heating performance, power consumption, and the change of COP. It is found that when the average outdoor temperature is 10℃, and the solar radiation reaches the peak of 571.5 W/m², the heating capacity of the direct expansion solar / air-assisted heat pump increased approximately 70% and its total heating capacity of the day increased about 12% compared with the air source heat pump. And when the temperature is between 0℃ and 8℃, the COP can still reach 3.46, the heating needs can be basically met. Furthermore, we optimized the new type heat pump, and hopes to gradually promote its practical application in cold regions.

Key words: solar energy, air source heat pump, direct expansion heat pump system, system performance, comparative analysis

摘要：

针对传统空气源热泵制热时极易出现室外机结霜的现象，提出了可同时吸收太阳能和空气能的新型太阳能/空气能直膨式热泵机组，把太阳能集热器和热泵蒸发器合二为一，使室外机结霜得到有效缓解。为了验证新型太阳能/空气能直膨式热泵机组性能优劣，分别搭建新型太阳能/空气能直膨式热泵系统和空气源热泵系统，在2月26日—3月2日期间，对邯郸某一农村建筑的地板辐射采暖用户进行5天实际测试，对比分析了两种系统的制热性能、耗电量和COP变化情况。通过测试发现室外平均温度为10℃，太阳辐射达到峰值571.5 W·m^-2时太阳能/空气能直膨式热泵的制热量较空气源热泵提高大约70%，全天总制热量较空气源热泵提高大约12%。0～8℃的低温状态时，COP值仍可达到3.46，基本满足建筑采暖需求。并在此基础上对太阳能-空气能直膨式热泵提出进一步的优化措施，逐步推广其在寒冷地区的实际应用。

关键词: 太阳能, 空气源热泵, 直膨式热泵系统, 系统性能, 对比分析