Heat pump system and heat pump system grading defrosting starting and ending point judgment method

Abstract

The invention provides a heat pump system. The heat pump system comprises a compressor, a condenser, a throttling device, a current converter and a casing evaporator, and further comprises a defrosting branch circuit. The defrosting branch circuit starts from an inlet of the condenser, passes the current converter and the casing evaporator in sequence and finally converges in front of the throttling device. A first temperature sensor and a second temperature sensor are arranged at suction and exhaust ports of the compressor correspondingly. A third temperature sensor is arranged on the casingevaporator. A first humidity sensor, a second humidity sensor and a micro differential pressure sensor are arranged at an inlet / outlet of the air side of the casting evaporator correspondingly. Through a heat pump system grading defrosting starting and ending point judgment method, the defrosting starting and ending points can be accurately judged, and grading defrosting can be implemented efficiently and accurately according to the defrosting degree. User comfort degree of the heat pump system can be effectively improved. The operating stability of the heat pump system can be improved. The defrosting efficiency can be improved. Accordingly, the energy utilization rate can be increased.

Description

technical field [0001] The invention relates to the field of heat pump systems, in particular to a heat pump system and a method for judging the start and stop of hierarchical defrosting thereof. Background technique [0002] When the air source heat pump is in heating operation in winter, the outdoor casing evaporator acts as an evaporator. Due to the low evaporation temperature, the surface temperature of the evaporator also drops, even lower than 0°C. When the outdoor air flows through When the evaporator is coiled, the moisture contained in it will precipitate to form a frost layer, and the gradually thicker frost layer will increase the heat conduction resistance, greatly reduce the air flow through the evaporator, and then reduce the heat transfer coefficient of the evaporator . With the thickening of the frost layer, the evaporation temperature will drop, the heating capacity will drop, and the performance of the fan will decline, which will affect the overall heatin...

AI Technical Summary

Problems solved by technology

Many of the above methods generally have problems such as large measurement errors in defrosting conditions, obvious waste of defrosting heat energy, poor user comfort, and inability to perform graded defrosting according to frosting conditions.

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