Defrosting method and device for supercooling of refrigerant in refrigerating circulating main pipeline

Abstract

The invention discloses a defrosting method and a device for supercooling of a refrigerant in refrigerating circulating main pipeline. The defrosting method comprises the following steps of shunting the refrigerant of the refrigeration main pipeline to an evaporator to be defrosted, wherein a split refrigerant is used as a defrosting medium, and heat is released to melt frost on the evaporator; the defrosted refrigerant is conveyed to a main pipeline cooler and evaporates and absorbs heat in the main pipeline cooler, and the refrigerant in the refrigeration main pipeline is subjected to subcooling; and the refrigerant subjected to defrosting before supercooling is introduced into the post-supercooling refrigerant, and the refrigerant is conveyed back to a compressor for circulation work. According to the defrosting method and the device, the defrosted refrigerant is used for supercooling the refrigerant in the refrigeration main pipeline, and the refrigerant with a low enthalpy value before supercooling is introduced into the supercooled refrigerant with a high enthalpy value, the compressor return air pressure is controlled within a reasonable range, and meanwhile, the return airsuperheat degree is controlled to be near the low value of the reasonable range, the refrigerating capacity of a refrigeration system is improved twice, and the refrigeration efficiency is improved.

Description

technical field [0001] The invention relates to a defrosting technology of a refrigeration system, in particular to a defrosting method and device for supercooling a refrigerant in a main circuit of a refrigeration cycle. Background technique [0002] During the operation of the refrigeration system, when the evaporation temperature is lower than 0°C, frost will appear on the evaporator, which will lead to a decrease in heat exchange and refrigeration efficiency, so defrosting treatment is required. [0003] The existing defrosting methods mainly include refrigerant defrosting and non-refrigerant defrosting. Among them, the refrigerant defrosting technology is an energy-saving technology. Defrosting; of course liquid refrigerants also exist as defrosting medium. In the common defrosting process, when the defrosting medium passes through the evaporator, it will release heat to defrost, and then enter the cooling evaporator for evaporative cooling. For example, in a continuo...

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Problems solved by technology

[0005] 1. Refrigerant after defrosting enters the evaporator of refrigeration to cool down the cooling object. The evaporation temperature must be lower than the temperature of the object to be cooled, so the cooling capacity of the refrigerant after defrosting will not be fully utilized. less quantity

[0006] 2. After defrosting, the refrigerant evaporates and absorbs heat after throttling through the expansion valve. When the refrigerant moves to the back section of the evaporation channel, it is almost completely evaporated and converted into gas. Although this can effectively prevent the liquid refrigerant from entering the compressor In this case, the compressor is protected, but since the gas refrigerant in the rear section of the evaporation channel will no longer evaporate and absorb heat, it will cause a waste of evaporation area in the rear section of the evaporation channel, and the evaporation temperature of the refrigeration system is higher than that of the refrigeration system during defrosting. When there is no defrosting, the evaporation temperature is low, the return air pressure is low, the superheat is high, and the cooling capacity is reduced

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