HIGH EFFICIENCY HEAT PUMP EQUIPPED WITH THE OPENING AND CLOSING CIRCUIT AND AUTOMATIC OIL RECOVERY

摘要

The present invention relates to a high efficiency heat pump having an automatic oil recovery and opening/closing circuit, recovering oil accumulated on the heat pump used as an evaporator through the automatic oil recovery and opening/closing circuit without use of an oil recovery machine when performing a cooling/heating operation using the heat pump, thereby reducing power consumption of the heat pump with respect to flow of a fluid such as oil or the like and increasing the coefficient of performance (COP). According to the present invention, a refrigerant of a compressor is recovered after flowing in an expansion valve of an indoor unit or an outdoor unit depending on switching of a four-way valve. At this time, the oil included in the refrigerant expanded by the expansion valve is introduced into the compressor depending on the opening and closing of a solenoid valve. Moreover, when the temperature of an inlet of the compressor is reduced when compared with the temperature of an outlet, a controller performs a control operation such that the solenoid valve is opened. Furthermore, the high efficiency heat pump allows a smooth flow of the oil, thereby remarkably reducing noise and vibration of the heat pump.