1. The field
The present invention relates a control method for a refrigerator.
2. Description of the Related Art
In a refrigerator having a cooling cycle in which refrigerants discharged from a compressor dividually flow to a freezer evaporator and a fridge evaporator through a 3-way valve, when the cooling cycle is reactivated while the compressor stops, refrigerants passages of the freezer evaporator and the fridge evaporator are closed and pump-down to operate the compressor is performed. By this configuration, the refrigerants in the freezer evaporator which are relatively in a low pressure are collected and the refrigerants are sent to the fridge evaporator.
Specifically, in general, in the case of a refrigerator in which the freezer evaporator and the fridge evaporator are provided in parallel, chambers are cooled in the sequence of cooling of the fridge, cooling of the freezer, and stopping of the compressor. Herein, when the refrigerants are sent to the freezer evaporator in order to cool the freezer, the pressure of the fridge evaporator is relatively high, such that refrigerants remaining the fridge evaporator are naturally collected by a pressure difference during cooling the freezer. That is, the refrigerants in the fridge evaporator get together with refrigerants of an outlet of the freezer evaporator to flow to an expansion device. However, when the refrigerants are sent to the fridge evaporator in order to cool the fridge, since the pressure of the freezer evaporator is lower than that of the fridge evaporator, the refrigerants cannot be smoothly collected and the refrigerants of the fridge evaporator may rather flow backward to the freezer evaporator.
Furthermore, at the time when the compressor stops, most refrigerants remain in the freezer evaporator. Therefore, when the compressor is reactivated to cool the fridge, it is difficult to collect the refrigerants of the freezer evaporator. For this reason, before the compressor stops, pump-down to collect the refrigerants of the freezer evaporator and gather the collected refrigerants in a condenser is performed. That is, a process of sending all the refrigerants gathered in the freezer evaporator and the fridge evaporator by closing both inlets of the freezer evaporator and the fridge evaporator and actuating the compressor is performed.
In the case of a refrigerator having such a system, the pressure of the outlet of the evaporator rapidly decreases to decrease to a vacuum level during the pump-down. In addition, the temperature of the evaporator rapidly decreases to a low temperature due to a sudden decrease in pressure and the resulting evaporation of the refrigerants. As a result, extremely low temperature refrigerants enter the compressor to decrease the temperature of the compressor and cause liquid compression, thereby deteriorating reliability of the compressor.