低温空气源热泵的现状与发展

Current Status and Development of Low Temperature Air-source Heat Pump

热泵作为一种节能技术受到了世界各国的普遍重视,而空气源热泵可从环境大气中吸取丰富的低品位能量,使用方便,安装费用较低,因此,空气源热泵成为热泵诸多型式中应用最为广泛的一种。但是,空气源热泵的应用范围受到气候条件的约束。随着室外温度的降低,用户的需热量不断增加。当室外气温很低时,空气源热泵的制热量不能满足用户采暖要求。同时,随着压缩机压力比的增加,其COP急剧下降,排气温度迅速升高,从而导致压缩机不能正常运行甚至损坏。国内外学者针对这样的问题提出了不同的解决方案。通过对一些低温空气源热泵研究成果的分析比较,对更好地促进空气源热泵技术的发展具有积极意义。

Heat pump has been regarded widely as a kind of energy-saving technique, and it can extract abundant second-class energy from ambience. Because of its convenience and economization, air-source heat pump is most expersively adopted in heat pumps. However, its usage is limited by ambience. With the decrease of outdoor temperature, the heat that is required increases. When outdoor temperature is low enough, the heat of air-source cannot satisfy the request. And with the increase of pressure rate of compressor, the heating COP decreases sharply, and the discharge temperature increases rapidly, which can make compressor dilapidate. Scholars have put forward many schemes to settle this problem. Several schemes are list and analyzed to improve the technique of air-source heat pump better.