Heat Pump System for Vehicle

A heat pump system for a vehicle, comprising:

• a first cooling device including a first radiator, a first water pump, and a first valve connected by a first coolant line and configured to circulate a first coolant on the first coolant line to cool at least one electrical component provided on the first coolant line;
• a second cooling device including a second radiator and a second water pump connected by a second coolant line, and configured to circulate a second coolant on the second coolant line;
• a third cooling device including a third coolant line connected to the second cooling device through a first valve, a third water pump provided on the third coolant line, and a battery module and configured to selectively circulate the second coolant on the third coolant line, the first cooling device having a first branch line connected to the first coolant line between a first radiator and a first water pump through the first valve provided on the first coolant line between the first radiator and the first water pump, the second cooling device having a second branch line separating the second coolant line and the third coolant line, and the third cooling device having a third branch line connected to the third coolant line through a second valve to form a closed circuit independent of the second cooling device;
• a chiller provided on the third coolant line, connected to a refrigerant line of an air conditioner through a refrigerant connection line, and configured to exchange heat between the second coolant selectively introduced through the third coolant line and a coolant selectively supplied from the air conditioner to control a temperature of the second coolant circulated on the third coolant line;
• a gas injection device configured to selectively expand a refrigerant supplied from an internal condenser included in the air conditioner and supply the expanded refrigerant to a heat exchanger of the air conditioner, and selectively supply a portion of the refrigerant to a compressor in the refrigerant supplied from the internal condenser to the compressor, wherein the heat exchanger is connected to the first coolant line and the second coolant line, respectively, so that the first coolant and the second coolant are configured to pass through, the gas injection device includes:
• a gas-liquid separator separating a gas refrigerant and a liquid refrigerant among the refrigerants introduced thereinto and selectively discharging the gas refrigerant and the liquid refrigerant;
• and
• a supply unit connected to the internal condenser through the refrigerant line so that the refrigerant supplied from the internal condenser is configured to be introduced;
• a HVAC module including an evaporator connected through the refrigerant line and including an opening/closing door provided therein to control external air passing through the evaporator to be selectively introduced into the internal condenser according to cooling, heating, and dehumidifying modes of the vehicle;
• a compressor connected between the evaporator and the internal condenser through the refrigerant line;
• a sub-condenser provided on the refrigerant line between the heat exchanger and the evaporator;
• an accumulator provided on the refrigerant line between the evaporator and the compressor and connected to the refrigerant connection line;
• and
• a refrigerant branch line configured to selectively introduce the refrigerant discharged from the heat exchanger directly into the accumulator between the heat exchanger and the sub-condenser through an operation of a refrigerant valve provided on the refrigerant line, wherein the refrigerant valve opens the refrigerant branch line in a heating mode of the vehicle.