Refrigerating unit, control method and refrigerating equipment

Abstract

The invention discloses a refrigerating unit, a control method and refrigerating equipment. The refrigerating unit comprises a compressor, a reversing valve, an outdoor heat exchanger, a throttling device and an indoor heat exchanger. The outdoor heat exchanger is provided with at least one middle outlet which is connected to the air suction side of the compressor through an auxiliary branch. The control method comprises the steps that when the reversing valve needs to be subjected to reversing switching, the exhaust pressure and the suction pressure of the compressor are detected, and the pressure difference delta Pj between the exhaust pressure and the suction pressure is calculated; whether delta Pj is larger than delta Ps or not is judged, wherein delta Ps is the lowest reversing pressure difference of the reversing valve; if yes, reversing switching of the reversing valve is carried out; and if not, the air suction side of the compressor is pressurized through the middle outlets. The auxiliary branch is led out of the outdoor heat exchanger to pressurize the air suction side of the compressor, so that the unit can meet the requirement for the lowest pressure difference during reversing switching of the reversing valve during defrosting under various working conditions.

Description

technical field [0001] The invention relates to the technical field of refrigeration units, in particular to a refrigeration unit, a control method and refrigeration equipment. Background technique [0002] There are various types of refrigeration units. Take the common air-cooled condensing unit as an example. The air-cooled condensing unit is a commercial refrigeration equipment used for cold storage. As the temperature of the indoor heat exchanger decreases, the water vapor in the indoor environment will flow on the surface of the indoor heat exchanger. When a frost layer forms, it is necessary to defrost the indoor heat exchanger to ensure the cooling effect. [0003] The air-cooled air-cooling unit in the prior art uses the four-way reversing valve to reverse the direction of the reverse cycle to achieve defrosting. Since the four-way reversing valve has the lowest pressure difference requirement when switching, that is, the four-way reversing valve piston When the act...

AI Technical Summary

Problems solved by technology

In some periods of severe working conditions, the pressure difference between the exhaust pressure and the suction pressure of the unit is very small, which is lower than the minimum pressure difference requirement when the four-way reversing valve is switched. In this case, the unit directly enters the defrosting control The reversing of the four-way reversing valve is unsuccessful, resulting in the failure of defrosting, and the refrigeration capacity of the unit cannot be exerted due to the influence of the frost layer, which in turn affects the storage effect of the cold storage items.

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