Multi-online system and low-temperature startup control method and device of multi-online system

Abstract

The invention discloses a multi-online system and a low-temperature startup control method and device of the multi-online system. The multi-online system comprises an outdoor unit and at least one indoor unit, wherein the outdoor unit is connected with the indoor units through tubing, and the outdoor unit comprises a compressor. The low-temperature startup control method comprises the following steps that when the multi-online system is controlled to conduct low-temperature startup, the maximum length of tubing between the outdoor unit and at least one indoor unit is acquired; the compressor is controlled to work for N periods of preset time according to N preset frequencies in sequence; and after the compressor works for the Nth period of preset time according to the Nth preset frequency,the frequency boost speed is determined according to the maximum length of tubing, and the operation frequency of the compressor is controlled to be increased to the target operation frequency from the Nth preset frequency at the frequency boost speed, wherein the N is a positive integer. As a result, the oil quantity of the compressor can be guaranteed in the low-temperature startup process, thecompressor is prevented from lacking oil, the requirement of heating on the indoor side is met, and the user experience is improved.

Description

technical field [0001] The invention relates to the technical field of air conditioners, in particular to a low-temperature start-up control method for a multi-split system, a low-temperature start-up control device for a multi-split system, and a multi-split system. Background technique [0002] The multi-connected system in the related art has the situation of starting at low temperature. However, the problem of the related technology is that during the low-temperature start-up process of the multi-line system, a large amount of refrigerant is usually dissolved in the refrigeration oil, resulting in no exhaust superheat of the compressor, and the oil separation effect is poor. A large amount of refrigerated oil is taken away in the oil, which makes it difficult to return the oil in the oil return capillary, and it is difficult to guarantee the oil quantity of the compressor. Contents of the invention [0003] The present invention aims to solve one of the technical prob...

AI Technical Summary

Problems solved by technology

However, the problem of the related technology is that during the low-temperature start-up process of the multi-line system, a large amount of refrigerant is usually dissolved in the refrigeration oil, resulting in no exhaust superheat of the compressor, and the oil separation effect is poor. A large amount of refrigerated oil is taken away in the oil, which makes it difficult to return oil in the oil return capillary, and it is difficult to guarantee the oil quantity of the compressor

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