HEAT PUMP SYSTEM FOR VEHICLE

A heat pump system for a vehicle can improve cooling and heating performance by increasing a flow amount of the refrigerant by employing a gas injection device selectively operated in at least one mode selected for air conditioning of a vehicle interior, and the heat pump system can include a compressor, a condenser, a first heat-exchanger, a second heat-exchanger, a first expansion valve, an evaporator, a first refrigerant connection line, a chiller, a second expansion valve, and a gas injection device, where flowing movement of the refrigerant can be controlled according to at least one mode for temperature adjustment of a vehicle interior and/or temperature adjustment of a battery module.