HEAT PUMP SYSTEM AND HEAT PUMP SYSTEM OPERATION METHOD

PROBLEM TO BE SOLVED: To provide a heat pump system that can be used for either use, a heat pump using heat from a plurality of heat sources or a heat pump that can supply heat in a plurality of temperature ranges, and an operation method for the heat pump system.SOLUTION: A heat pump system 1 comprises: an evaporator 2; a condenser 3; a first channel 4A; a second channel 4B; a bypass channel 5; a heat exchanger 6 provided in the bypass channel 5, and causing heat exchange between refrigerant R and outside; compressors A1 and A2 provided between a first connection portion S1 and the evaporator 2 and between the first connection portion S1 and the condenser 3, respectively, and pumping the refrigerant R from the evaporator 2 toward the condenser 3; and expansion valves B1 and B2 provided between a second connection portion S2 and the evaporator 2 and between the second connection portion S2 and the condenser 3, respectively, and expanding the refrigerant R from the condenser 3 toward the evaporator 2.