| 摘要 |
PROBLEM TO BE SOLVED: To appropriately control a door heater in a cooling storage to securely prevent frost formation on a heat insulating door. SOLUTION: An outside air temperature is detected by an outside air temperature sensor 85, and an indoor temperature of a refrigerating chamber 20 is detected by a right refrigerating chamber temperature sensor 80. A microcomputer 90 compares the outside air temperature output from the outside air temperature sensor 85 with the indoor temperature output of the refrigerating chamber 20 from the right refrigerating chamber temperature sensor 80 and determines whether the outside air temperature is lower than the detected indoor temperature of the refrigerating chamber 20 or not. When it is determined that the outside air temperature is lower than the indoor temperature of the refrigerating chamber 20, the microcomputer 90 performs the duty control of the door heater 39 and performs control so that the duty factor of the door heater 39 becomes 70%. When it is determined that the outside air temperature is not lower than the indoor temperature of the refrigerating chamber 20, the microcomputer 90 calculates a temperature difference between the detected indoor temperature of the refrigerating chamber 20 and the outside air temperature and determines whether the temperature difference is higher than 25°C or not. When the outside air temperature is high and the temperature difference is larger than 25°C, the microcomputer performs control so that the duty factor of the door heater 39 becomes 60%. COPYRIGHT: (C)2011,JPO&INPIT |
