Air conditioner

Abstract

The invention relates to an air conditioner, aiming at shortening the time for defrosting while defrosting and heating are simultaneously proceeded to ensure the indoor comfort. In case of starting the defrosting for an outdoor heat exchanger during the heating, a part of a main loop switch valve (713) and a bypass switch valve (715) is under switch control, other outdoor heat exchangers (732,733, 734) are used to implement defrosting and heating operation while a part (713) of the outdoor heat exchanger (73) is defrosted, and heating operation is resumed subsequent to repeatedly implementing defrosting and heating operation on all the outdoor heat exchanger sequentially by means of control, in addition, upon the ending of the defrosting and the heating operation, the outdoor exchanger with large frost-covering amount is detected and judged, the main loop switch valve and the bypass switch valve of this outdoor exchanger are subjected to switch control, and other outdoor heat exchangers are used to implement restrictive defrosting and heating operation while the defrosting only for this outdoor heat exchanger is implemented.

Description

technical field [0001] The present invention relates to an air conditioner, in particular, to an air conditioner that simultaneously performs defrosting of an outdoor heat exchanger and indoor heating. Background technique [0002] During the heating operation of the air heat source heat pump air conditioner, if the humidity of the outdoor air is high, frost will occur on the outdoor heat exchanger. When frost occurs, since the ventilation path of the outdoor heat exchanger is narrowed, the amount of outdoor air circulating in the outdoor heat exchanger is reduced. When the amount of circulating outdoor air decreases, the amount of heat exchanged decreases, and the evaporation temperature of the refrigerant flowing in the outdoor heat exchanger decreases accordingly. When the evaporating temperature of the refrigerant decreases, the surface temperature on the outside of the outdoor heat exchanger also decreases, and frost formation is more likely to occur, and the frost for...

AI Technical Summary

Problems solved by technology

[0013] In the case of starting the heating operation when the outside air temperature is low in the winter morning, it is necessary to start defrosting before the room temperature reaches the set temperature. After the operation, the reverse cycle defrosting operation is started, so there is a problem that the room temperature drops greatly during the defrosting process, which destroys the comfort, and the time required for the room temperature to reach the set temperature becomes longer.

[0014] In the air conditioner of Patent Document 1, since defrosting is always performed during heating operation, there is a problem that indoor heating is always performed in a state where the heating capacity is lowered.

In addition, since the defrosting of the smallest part of the outdoor heat exchanger divided into three is sequentially switched, there is a problem that the defrosting time becomes longer.

[0015] In the air conditioners of Patent Document 2 and Patent Document 3, since the outdoor heat exchangers are divided into two rows in front and behind with respect to the air flow and defrosted alternately, one of the divided outdoor heat exchangers is defrosted. The resulting melted water cannot be used to melt the frost of the other party, so it is impossible to efficiently defrost in a short time

[0016] In the air conditioner of Patent Document 4, since the outdoor heat exchanger is separated left and right with respect to the air flow and the defrosting is performed alternately, the melted water generated by the defrosting of one of the divided outdoor heat exchangers cannot be used. Due to the melting of frost on the other side, it is impossible to defrost efficiently in a short time

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