Characteristics Of Low Temperature Ashp Air Condition

Low temperature air-sourced heat pump air conditioner could meet the indoor heating demand even the environment temperature is lower than -15℃, and it also has a good stability, security and heating performance.A newly low temperature air-sourced heat pump air conditioner——the main and auxiliary compressors combined heat pump air conditioner, is proposed in this study. The main and auxiliary compressors combined heat pump air conditioning has two separate sets of unit that shares a set of heat exchangers. The heat exchanger arranges two sets of independent circulation loop with different refrigerant after special processing improvements, which was used for the main and auxiliary compressors, respectively.This paper consists of the following three parts:1. The study of function performance in the main and auxiliary compressors combined heat pump air conditioner. This article describes the structure, working principle, refrigerant cycle and defrosting mode of newly heat pump air conditioner detaily, which could also solve the mismatch problem of building cooling and heating load. The main compressor works for cooling and heating while the auxiliary compressor works for cooling or defrosting. So the main and auxiliary compressors have mutual function complementation.2. The defrosting of the main and auxiliary compressors combined heat pump air conditioner. A newly defrosting method is used in this heat pump air conditioner, which utilizes the heating cycle of auxiliary compressor to melt the frost of outdoor heat exchanger, and it could solve the following problems:(l)It could avoid the high energy consumption of electric heating defrosting; (2) this method could avoid the interior impact on the compressor and the damage to the valves of reverse cycle defrosting; (3) it could avoid the inadequate heating source problem of hot gas bypass defrosting. All in all, this method has high defrosting efficiency, low energy consumption, high security and fast defrosting speed.3. The function performance experiments and analysis of the main and auxiliary compressor combined heat pump air conditioner. The following two conclusions were draw through experiments under different weather conditions in the TianJin area. (1) The newly heat pump air conditioner possesses a good cooling and heating effect which could meet the customer’s demand. (2) This units have a short defrosting time interval of outdoor heat exchanger, good defrosting uniformity and low energy consumption.