Cooling Storage Cabinet and Method of Operating Thereof

Abstract

When an internal temperature of a freezing compartment becomes lower than a lower limit temperature TF(OFF) during R-compartment F-compartment alternate cooling, a request for start of R-individual overcool preventing control is made. Then, the rotational speed of the compressor is decreased by one stage and, subsequently, a three-way valve comes to a “R-side open state”, and thus individual cooling of the refrigerating compartment is executed. Thereafter, after a set time, the rotational speed of the compressor is decreased by one stages. When the refrigerating compartment becomes lower than a lower limit temperature TR(OFF), a request for stop of the R-individual overcool preventing control is made. Then, the process shifts to individual cooling of the freezing compartment and then, after waiting for the freezing compartment to again become lower than the lower limit temperature, the compressor is stopped. When shifted to the individual cooling of the refrigerating compartment, the rotational speed of the compressor is drastically decreased in a short time, i.e. the cooling capacity is drastically decreased.

Description

TECHNICAL FIELD[0001]The present invention is related to a cooling storage cabinet having a plurality of evaporators and supplying refrigerant from a single compressor to the evaporators, and a method of operating the same.BACKGROUND ART[0002]A known cooling storage cabinet is described in Patent Document 1. In this art, a freezing compartment and a refrigerating compartment are formed by separating the inside of a heat-insulating storage cabinet body. The freezing compartment and the refrigerating compartment each are heat insulated. The freezing compartment and the refrigerating compartment each have respective set temperatures differing from each other. Each of the compartments has an evaporator, and a single compressor supplies refrigerant alternately to evaporators to cool the compartments.[0003]More specifically, a cooling cycle is configured as follows. An inverter motor operates a compressor. An outlet side of the compressor is connected to a condenser. The downstream side o...

AI Technical Summary

Benefits of technology

The present invention relates to a cooling storage cabinet with two storage compartments that can be individually cooled. The cabinet includes an inverter compressor, a condenser, a valve unit, constriction units, evaporators, and a refrigerant circulation path. The invention provides a method for controlling the compressor to supply refrigerant to the evaporators while changing the rotational speed of the inverter compressor based on the set temperatures of the storage compartments and the internal temperatures of the compartments. The method can also include decreasing the rotational speed of the inverter compressor when the internal temperature of one of the storage compartments becomes lower than the set temperature, stopping the inverter compressor when the internal temperature of both compartments become lower than the set temperature, and decreasing the rotational speed of the inverter compressor when the internal temperature of one of the storage compartments becomes higher than the set temperature. The invention also includes a compressor control means that can decrease the rotational speed of the inverter compressor in stages or at predetermined intervals to ensure proper cooling and motor oil circulation. The technical effects of the invention include efficient cooling of the storage compartments, improved control of the cooling process, and reduced risk of overcooling.

Problems solved by technology

However, because of such a higher rotational speed of the compressor, there is a concern of over cooling capacity, which results in over cooling of the refrigerating compartment.

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