Heating-based defrost control method of multi-split air-conditioning system

Abstract

The invention provides a heating-based defrost control method of a multi-split air-conditioning system. Each indoor machine and each outdoor machine are respectively provided with one switch valve for controlling operation of each indoor machine or each outdoor machine. The method comprises the following steps of: when the multi-split air-conditioning system is in an indoor heating operation state, judging whether a defrost condition is met or not; if the defrost condition is met, switching operation of a four-way valve so as to enable the outdoor machines to perform heating-based defrosting, and regulating to close at least one switch valve of one indoor machine needing to further heat among the multiple indoor machines; and regulating to open at least one switch valve of residual indoor machines except for the indoor machine needing to further heat. The heating-based defrost control method is capable of effectively overcoming the defects that a refrigerant of an air conditioner in the prior art inevitably absorbs away heat during a heating-based defrosting process to cause indoor temperature decrease and influence on indoor human body comfort, and reducing occurrence of a situation that temperature in a heating indoor machine room is reduced due to heat absorption of a low-temperature refrigerant for defrosting during a defrosting process to the greatest extent.

Description

technical field [0001] The invention belongs to the technical field of air conditioning, and in particular relates to a heating and defrosting control method for a multi-connected air conditioning system. Background technique [0002] When the air conditioner in the prior art is heating indoors, the outdoor unit often frosts when the ambient temperature is low. However, in the prior art, the hot air defrosting method is generally used for defrosting, that is, through four The reversing of the through valve forms a refrigeration cycle, and the high-temperature gaseous refrigerant discharged from the compressor first passes through the outdoor heat exchanger for defrosting. However, when the air conditioner using this technology is defrosting, because it belongs to cooling operation, that is, the refrigerant first defrosts on the outdoor heat exchanger and then becomes a low-temperature liquid. When it flows through the indoor unit, due to the low temperature of the refrigeran...

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Problems solved by technology

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the air conditioner in the prior art will inevitably cause the indoor temperature to drop due to the heat absorption of the refrigerant during heating and defrosting, which will affect the comfort of the indoor human body, thereby providing a multi- On-line air conditioner heating and defrosting control method

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