The control device and method for controlling a door heater in cold storage

摘要

PPROBLEM TO BE SOLVED: To surely obtain a desired temperature difference in upper and lower parts of a cooling refrigerating chamber. PSOLUTION: 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 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 a 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 indoor temperature of the refrigerating chamber 20 and the outside air temperature. When the outside air temperature becomes lower to further reduce the temperature difference and the temperature difference is smaller than 25°C, it is determined whether or not the temperature difference is larger than 15°C. When the temperature difference is larger than 15°C, control is performed so that the duty factor becomes 50%. PCOPYRIGHT: (C)2011,JPO&INPIT