Defrosting control method for multi-on-line variable-frequency air conditioners

Abstract

The invention relates to multi-on-line variable-frequency air conditioners and provides a defrosting control method for the multi-on-line variable-frequency air conditioners in order to solve the problem that system performance is affected as a system cannot be defrosted normally. The method comprises the steps that firstly, the system detects the temperature of an outdoor environment and the temperature of heat exchangers of all outdoor units and figures out the temperature difference of the outdoor units, and meanwhile the system detects the continuous operation time of compressors of all the outdoor units; secondly, the system judges whether the continuous operation time of the compressors of the outdoor units is greater than or equal to the set operation time of the compressors and judges whether the temperature difference of the outdoor units is within a frosting temperature difference area or not at the same time; if yes, the system issues a defrosting application to a host; if not, the operation is repeated; finally, after receiving the defrosting application of any outdoor unit, the host judges whether to allow defrosting or not according to the current operation condition of the system; if yes, the host issues defrosting commands to all the outdoor units; if not, the operation is repeated; after receiving the defrosting commands, the outdoor units operate according to an automatic defrosting program and perform defrosting. The defrosting control method is suitable for the multi-on-line variable-frequency air conditioners.

Description

technical field [0001] The invention relates to a multi-connected frequency conversion air conditioner, in particular to a defrosting control method for the multi-connected frequency conversion air conditioner. Background technique [0002] When the air conditioner is heating, the liquid refrigerant at room temperature and pressure will absorb the surrounding heat and vaporize in the outdoor unit, the temperature around the outdoor unit will decrease, and the air temperature next to it will be higher, and frost will form on the outdoor unit at this time. After the air conditioner is frosted, how to detect the amount of frost through the software? The basis for software judgment is generally based on the difference between the temperature of the outdoor unit heat exchanger (outer disk temperature) and the outdoor ambient temperature. Generally, it is judged that the outer disk is a certain temperature lower than the outdoor temperature. It is judged that there is frost, and t...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: 1. When there are multiple outdoor units outdoors, each outdoor unit will automatically defrost when it detects that defrosting is required, which will cause frequent defrosting of outdoor units in the multi-connected system, which will affect heating Effect

2. When the outdoor ambient temperature is different, the temperature difference between the outdoor ambient temperature and the outdoor heat exchanger temperature will also be different for the same thickness of frost. If the temperature difference is set to a fixed value, it will cause frost in some working conditions, which cannot be accurately judged. Frosting under working conditions did not reach the thickness of defrosting, and wrong defrosting was carried out

Regardless of whether the frost has reached the defrosting condition and cannot be defrosted, or the defrosting condition has not been reached and the defrosting is performed by mistake, it will affect the performance of the system, resulting in poor heating effect

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