PURPOSE: To provide a defrosting device of a cooling unit wherein defrosting of a cooler and drain plate can be performed without overheating the cooler.
CONSTITUTION: There are provided a cycle wherein a compressor 14, condenser 17, expansion valve 23, and cooler 21 are connected in series, a drain plate 25 for receiving drain generated in the cooler 21, a first defrosting means which sends high temperature, high pressure refrigerant delivered from the compressor 14 directly to the cooler 21 to heat it, and a second defrosting means which heats the drain plate 25 by means of an electric heater 26 provided in the drain plate 25. Further there are provided a temperature sensor 27 of the first defrosting means which is provided in the cooler 21 to sense the completion of defrosting, a temperature sensor 28 of the second defrosting means which is provided in the drain plate 25 to sense the completion of defrosting, and a plurality of return set temperatures from the sensor 27 and the sensor 28, and also a set element 31 which selects each return set temperature to set it.
YUZURIHA HIROYUKI
UEKI MOTOJI
