Defrosting control device and method for air source heat pump system

Abstract

The invention discloses a defrosting control device for an air source heat pump system. The device is characterized by comprising a compressor, a four-way reversing valve, an indoor heat exchanger, a gas-liquid separator, a throttling part, an outdoor heat exchanger, a phase change heat accumulator, a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a first bypass pipeline and a second bypass pipeline, wherein the phase change heat accumulator is connected to the downstream position of the indoor heat exchanger to be used as a subcooler when the system supplies heat and to be used as a low-temperature heat source when the system defrosts, high and low pressure butt joint of the system before and after defrosting is completed by switching the bypass pipelines and the solenoid valves, so that the four-way valve does not perform reversing, the indoor temperature does not decrease, and the indoor comfort is guaranteed. The device has the advantages of simple structure, reliable performance, good defrosting effect, long service life and the like, and the method which is scientific, reasonable, high in adaptability and high in popularization and application value is provided.

Description

technical field [0001] The invention relates to the field of refrigeration and heat pumps, and relates to a defrosting control device and method for an air source heat pump system. Background technique [0002] Air source heat pump is an energy-saving and widely used heating equipment. However, during the heating operation in winter, the fins of the outdoor unit will frost, and the frost layer will block the air passage, which seriously affects the heating effect. When the frost layer reaches a certain thickness, it must be defrosted. The existing defrosting methods include electric heating defrosting method, reverse cycle defrosting method, hot gas bypass defrosting method and dehumidification method to prevent frosting, but these defrosting methods have disadvantages. The electric heating defrosting method has the advantages of simple system, complete defrosting, and simple control, but the disadvantage is that it consumes a lot of power and is not suitable for large-scal...

AI Technical Summary

Problems solved by technology

The electric heating defrosting method has the advantages of simple system, complete defrosting, and simple control, but the disadvantage is that it consumes a lot of power and is not suitable for large-scale devices; the reverse cycle defrosting method is simple and easy to implement, and the defrosting effect is good. When frost occurs, the compressor must be shut down first to complete the high and low pressure connection of the system, then the four-way valve is reversed, and then the compressor is restarted to make the system run in reverse to defrost. This process will have a relatively serious impact on the components of the system. Reliability is affected, and this defrosting method lacks low-temperature heat during defrosting, so it needs to absorb heat from the heating room, causing the room temperature to drop sharply. Reduced indoor comfort;

[0003] In the hot gas bypass defrosting method, due to the increase of the inlet temperature of the evaporator, the heating capacity of the system is reduced. The energy of the hot gas bypass defrosting mainly comes from the input work of the compressor. It causes "liquid shock", which affects the service life of the compressor, and the energy loss of the refrigerant flowing through the liquid separator and the liquid capillary is relatively large, the defrosting time is longer than the reverse cycle defrosting time, and no heat is supplied to the room during defrosting. Affects indoor comfort; the dehumidification method prevents frosting. This method mainly prevents frosting by reducing the air humidity at the entrance of the outdoor unit. Affected the popularization and application of the technical solution

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