HEAT PUMP WITH INJECTION CYCLE

摘要

PURPOSE: A heat pump with injection cycle is provided to perform a high efficiency operation regardless of outdoor temperature during heating operation, and ensure sufficient flow amount of circulating refrigerant when the operation mode is switched to a cooling operation. CONSTITUTION: A heat pump comprises a compressor(1) for compressing refrigerant into a high temperature high pressure gas; a four-way valve(2) for changing the flow direction of the refrigerant; an indoor heat exchanger(3) for converting the refrigerant into a high temperature high pressure liquid and radiates heat to the outside; a first expansion valve(21) for expanding the flowing refrigerant; a refrigerant heating unit(23) for heating the refrigerant; a gas-liquid separator(27) for separating the flowing refrigerant into gas and liquid; a second expansion valve(22) connected to the gas-liquid separator and which expands the liquid refrigerant; an outdoor heat exchanger(4) for changing the liquid refrigerant into gaseous state and absorbing heat from the outdoor area; and an injection pipe(26) connecting the gas-liquid separator and the compressor.