Defrosting method of three-pipe heating recovery system

Abstract

The invention discloses a defrosting method of a three-pipe heating recovery system. An outdoor unit of the three-pipe heating recovery system comprises more than two outdoor heat exchangers, more than two three-way valves, more than one compressor, a high-pressure liquid pipe, a low-pressure air pipe and a high-pressure air pipe; and in a heating mode or a mixed refrigerating/heating mode, one outdoor heat exchanger is in a condenser defrosting state, and the other outdoor heat exchanger is certainly not in a condenser defrosting state. In the defrosting process, the defrosting sequence of the outdoor heat exchangers can be adjusted at will according to the actual condition. In the defrosting method, the defrosting time of all the outdoor heat exchangers of the outdoor unit of the three-pipe heating recovery system is staggered, therefore, the capacity of an indoor machine for continuously supplying heat towards indoor is maintained, the influence on indoor heating effect is reduced, and the using comfort of an air conditioner is improved, so that the defrosting method achieves the characteristics of simpleness and flexibility for control, no need of additional electric-heating defrosting equipment, high defrosting efficiency, less influence on heating effect of the indoor unit in the defrosting period, and the like.

Description

technical field [0001] The invention relates to a three-pipe heat recovery system, in particular to a defrosting method for the three-pipe heat recovery system. Background technique [0002] In some low-temperature or high-humidity environments, frosting of the outdoor heat exchanger in the outdoor unit of the three-pipe heat recovery system is inevitable. There are several defrosting methods for the existing three-pipe heat recovery system: 1) Add an electric heating defrosting device to realize the defrosting effect through electric heating, but this method needs to add an electric heating device, which has high cost, high power consumption, and low efficiency. Extremely high; 2) There is only one outdoor heat exchanger, and the system switches the flow direction of the refrigerant, so that the outdoor heat exchanger originally used as an evaporator is transformed into a condenser, which uses the refrigerant to condense to release heat and melt the frost accumulated on the...

AI Technical Summary

Problems solved by technology

[0002] In some low-temperature or high-humidity environments, frosting of the outdoor heat exchanger in the outdoor unit of the three-pipe heat recovery system is inevitable. There are several defrosting methods for the existing three-pipe heat recovery system: 1) Add an electric heating defrosting device to realize the defrosting effect through electric heating, but this method needs to add an electric heating device, which has high cost, high power consumption, and low efficiency. Extremely high; 2) There is only one outdoor heat exchanger, and the system switches the flow direction of the refrigerant, so that the outdoor heat exchanger originally used as an evaporator is transformed into a condenser, which uses the refrigerant to condense to release heat and melt the frost accumulated on the heat exchanger. But the disadvantage is that the switched indoor unit acts as an evaporator, which is equivalent to running the cooling mode, which runs counter to the user's needs; 3) Stop defrosting and let the frost melt naturally. Although this method is the most energy-saving, it is at the expense of The user's heating effect is the premise, and the outdoor ambient temperature is generally low when frosting occurs, the defrosting speed is slow, and the efficiency is very low

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