METHOD FOR CONTROLLING OPENING OF ELECTRONIC EXPANSION VALVE FOR MULTI-HEAT PUMP

摘要

PURPOSE: A method for controlling an electronic expansion valve of a multi-heat pump is provided to prevent a pipe temperature from dropping below zero by controlling opening of an electronic expansion valve, thereby preventing a pipe from being frozen. CONSTITUTION: A pipe temperature of each indoor unit is detected in the middle of cooling operation. It is judged whether the detected pipe temperature is lower than a first set temperature. If not, the pipe temperature is controlled by regular control opening of an electronic expansion valve. If so, it is judged whether the detected pipe temperature is lower than a second set temperature. If so, the electronic expansion valve is opened at first reference opening for a period of first time. If not, the electronic expansion valve is opened at second reference opening for a period of second time.