DEFROST SYSTEM FOR REFRIGERATION DEVICE AND COOLING UNIT

摘要

A defrost system for refrigeration devices, comprising: a cooler provided inside a freezer and having a heat exchange pipe arranged so as to have a height difference inside the casing and a drain receiving section provided below the heat exchange pipe; a refrigerator for cooling and liquefying CO2 refrigerant; a refrigerant circuit for circulating in the heat exchange pipe CO2 refrigerant that has been cooled and liquefied by the refrigerator; a bypass pipe connected between the inlet and outlet paths of the heat exchange pipe and for forming a CO2 circulation path including the heat exchange pipe; a switch valve provided in the inlet and outlet paths of the heat exchange pipe, for closing during defrost and making the CO2 circulation path a closed circuit; a pressure adjustment unit for adjusting the pressure of the CO2 refrigerant that circulates through the closed circuit during defrost; and a brine circuit arranged adjacent to a lower area of the heat exchange pipe, inside the cooler, and including a first guide path forming a first heat exchange section that heats the CO2 refrigerant circulating through the heat exchange pipe by using brine in the lower area of the heat exchange pipe. The CO2 refrigerant is naturally circulated in the closed circuit by a thermosiphon action during defrost.