Air source heat pump

Abstract

The invention discloses an air source heat pump. The air source heat pump comprises a first heat exchanger, an indoor unit, an outdoor unit, a bypass defrosting unit and a controller; the first heat exchanger comprises a first heat exchange tube set and a second heat exchange tube set; the indoor unit comprises a first refrigeration circulation loop, and the first refrigeration circulation loop isformed by connecting a first compressor, a first four-way valve, the first heat exchange tube set and a second heat exchanger; the outdoor unit comprises a second refrigeration circulation loop, andthe second refrigeration circulation loop is formed by connecting a second compressor, a second four-way valve, the second heat exchange tube set and a third heat exchanger; the bypass defrosting unitis located between the second compressor and the third heat exchanger and can guide gas on the exhaust side of the second compressor to the third heat exchanger when communicating with the second compressor and the third heat exchanger; and when it is detected that the temperature decay rate of the liquid pipe side of the third heat exchanger reaches a first preset value, the bypass defrosting unit is controlled to communicate with the second compressor and the third heat exchanger, and when it is detected that the temperature decay rate of the liquid pipe side is larger than or equal to a second preset value, the first four-way valve and the second four-way valve are controlled to be reversed. According to the air source heat pump, the problem that reverse cycle defrosting of an existingair source heat pump causes large damage to system performance is solved.

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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