Defrosting method for heat pump type air conditioner

Abstract

The invention discloses a defrosting method for a heat-pump type air conditioner, which decides whether the defrosting operation mode, namely setting environment determination temperature t<1> and t<2> and three constants a, b and c, is carried out by combination of coil tube temperature T of an outdoor heat exchanger, outdoor temperature T, actual heating time H and set heating time h; under the following conditions, the unit starts the defrosting operation mode: 1. when T is less than or equal to t<1> and more than or equal to t<2>, if the coil tube temperature T of the outdoor heat exchanger meets the condition of T less than a, T plus c and H larger than h in a continuous M minutes, the unit starts to defrost; 2. when T is less than t<2>, if the coil tube temperature T of the outdoor heat exchanger meets the conditions of T less than b, T plus c and H larger than h in a continuous M minutes, the unit starts to defrost. The defrosting method has the advantages of shortening defrosting time, improving defrosting efficiency, leading to thorough defrosting and greatly improving heating efficiency.

Description

Technical field [0001] The invention relates to a defrosting method for a heating mode of an air conditioner, in particular to a defrosting method for a heat pump type air conditioner. Background technique [0002] The defrosting method of the traditional heat pump air conditioner is generally to detect the temperature of the central coil of the outdoor heat exchanger and the heating operating time. When the heating operating time is greater than the set value and the temperature of the central coil is less than the set value, the defrosting starts. The defrosting method must first determine whether the compressor has been running continuously for a specified time before the unit enters the defrosting method, and the specified time is fixed. When the outdoor environment temperature is too low, this defrosting method is likely to cause frequent defrosting of the unit and reduce the heating efficiency; at the same time, when the outdoor humidity is high, due to the existence of a f...

AI Technical Summary

Problems solved by technology

When the outdoor ambient temperature is too low, this defrosting method will easily cause frequent defrosting of the unit and reduce the heating efficiency; The heater is covered with thick frost, which leads to a sharp decline in the heating effect, and greatly increases the defrosting time. The defrosting efficiency is low, and the defrosting will not be complete, which greatly reduces the heating efficiency.

[0003] A defrosting method for a heat pump air conditioner is disclosed on the website of the State Intellectual Property Office. It determines whether to defrost according to the first temperature difference between the indoor pipe temperature and the room temperature and the second temperature difference and the reference value. It changes the traditional The problem of fixed time in the defrosting method improves the heating efficiency, but because the defrosting method does not consider the outdoor ambient temperature, absolute humidity and defrosting time, it cannot be automatically adjusted according to the frosting of the outdoor heat exchanger. Therefore, when the outdoor ambient temperature is lower than 0°C and the humidity is greater than 70°C, the heating time is short, the defrosting time is long, the frost cannot be completely removed, the defrosting efficiency is low, and the heating efficiency is still not ideal

[0004] In addition, in the defrosting method of the heat pump air conditioner in the prior art, when the unit enters the defrosting, the indoor fan generally stops running, so there is a large amount of liquid return to the outdoor unit when the defrosting is in progress, which will lead to defrosting. The time is greatly extended, and if it is not handled properly, it may cause liquid shock of the compressor

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