HEAT PUMP SYSTEM FOR VEHICLE

An embodiment heat pump system for a vehicle includes a compressor that compresses a refrigerant, a condenser connected to the compressor through a refrigerant line that condenses the refrigerant by heat-exchanging the refrigerant with a coolant, an evaporator connected to the condenser through the refrigerant line that evaporates the refrigerant, a gas injection device that selectively expands and flows the refrigerant and selectively supplies a portion of the supplied refrigerant to the compressor, a first refrigerant connection line having a first end connected to the refrigerant line and a second end connected to the gas injection device, a chiller that adjusts a temperature of the coolant by heat-exchanging the refrigerant introduced through the first refrigerant connection line with the coolant, and a second refrigerant connection line having a first end connected to the refrigerant line and a second end connected to the gas injection device.