Cooling medium circuit for ice making machine etc

Disclosed is a cooling medium circuit for ice making machines and the like, comprising a freezing circuit in which a high-pressure and high-temperature vaporized cooling medium compressed in a compressor is fed to a condenser, the cooling medium liquefied through condensation in the condenser is fed to an expansion means through a first solenoid valve, the cooling medium expanded and vaporized through the expansion means is fed to an evaporator to perform heat exchange and the thus heated vaporized cooling medium is fed back to the compressor; and a hot gas circuit in which the high-pressure and high-temperature vaporized cooling medium fed from the compressor is partly by-passed to the evaporator through a second solenoid valve and a choking means to achieve ice releasing and the like in the evaporator, wherein the state of the first solenoid valve and that of the second solenoid valve can be changed over synchronously each time the ice making machine is switched to freezing operation or to ice releasing operation to assume states contrary to each other; and additionally a bypass circuit where the cooling medium fed from the condenser is designed to be partly by-passed to the compressor through a third solenoid valve. According to this constitution, the ice releasing capacity of the evaporator can greatly be improved independent of the ambient temperature.