An air source heat pump

Abstract

The invention discloses an air source heat pump, comprising: a first heat exchanger; a first heat exchange tube group and a second heat exchange tube group; 1. The first heat exchange tube group is connected to the second heat exchanger; the second refrigeration cycle is formed by connecting the second compressor, the second four-way valve, the second heat exchange tube group and the third heat exchanger; The defrosting unit is connected between the second compressor and the third heat exchanger, and the gas on the discharge side of the second compressor can be led to the third heat exchanger when it is turned on; the controller, when it detects that the third heat exchanger When the decay rate of the temperature on the liquid pipe side of the heater reaches the first preset value, the bypass defrosting unit is controlled to communicate; when it is detected that the decay rate of the liquid pipe side temperature is greater than or equal to the second preset value, the first four-way valve is controlled and the second four-way valve reversing. The invention solves the problem that the reverse cycle defrosting of the existing air source heat pump greatly damages the system performance.

Description

technical field [0001] The invention relates to the technical field of cooling and heating equipment, in particular to an improvement of the structure of an air source heat pump. Background technique [0002] The cascade high-temperature heat pump system can produce 80°C high-temperature water to meet user needs. Under low-temperature heating conditions, the heat exchanger of the outdoor unit is prone to frost. Air source heat pumps, including outdoor units and indoor units, four-way valve reversing defrosting, this method is used in the defrosting process of most heat pump systems, this method can defrost quickly, and the defrosting effect is good, but it will also cause The temperature of the outlet water drops significantly in a short time, and the temperature of the outlet water drops, which affects the user's use, and the method of reversing the defrosting through the four-way valve is equivalent to controlling the reverse cycle operation of the entire refrigeration sy...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem in the prior art that the air source heat pump adopts the four-way valve reverse cycle to defrost, the indoor outlet water temperature is low and the system performance is greatly damaged, the present invention provides an air source heat pump, which can realize hot gas bypass defrosting and The four-way valve reversing defrost can be switched. When heating at low temperature, the defrosting can be bypassed through hot gas. Only when the frost layer on the heat exchanger is thick can the four-way valve reversing defrost be carried out to ensure the water outlet. end temperature, while reducing damage to system performance

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