Heat pump system for vehicle

A heat pump system for a vehicle comprising:

• an air conditioner;
• a battery cooling line connected with a battery module, and water flowing through the battery cooling line;
• a chiller provided at the battery cooling line, connected with a coolant line of the air conditioner through a connection line, and configured to control the cooling water selectively introduced into the chiller by heat-exchanging the cooling water with a coolant;
• a cooling part comprising a radiator and a first water pump connected with each other by a cooling line, configured to circulate the water through the cooling line to cool an electrical device, and connected with the battery cooling line through a first valve;
• and
• a bypass line configured to selectively connect the connection line with the coolant line through a second valve provided at the coolant line,
• wherein the air conditioner comprises:
• an HVAC module comprising an opening/closing door connected with through the coolant line to control external air passed through an evaporator to be selectively introduced into an internal condenser according to a cooling mode, a heating mode, or a heating and dehumidification mode of the vehicle,
• a compressor connected with through the coolant line between the evaporator and the internal condenser,
• an accumulator provided between the compressor and the evaporator at the coolant line,
• an external condenser connected with the internal condenser through the coolant line, and disposed forward of the vehicle,
• a first expansion valve provided at the coolant line to connect the external condenser with the evaporator,
• a dehumidification line including one end connected with the coolant line between the internal condenser and the external condenser and another end connected with the coolant line between the evaporator and the first expansion valve, and comprising a third valve,
• a defrost line connected with the coolant line between the external condenser and the first expansion valve through a fourth valve provided at the coolant line between the internal condenser and the external condenser, and
• a second expansion valve provided at the connection line,
• wherein the first valve connects the battery cooling line with the cooling line connected with the electrical device between the radiator and the chiller, the battery cooling line comprises a first branch line to connect the chiller with the battery module through the first valve, the cooling line comprises a fifth valve to selectively connect the cooling line with the battery cooling line between the radiator and the battery module, and the cooling line for connecting the first valve with the electrical device comprises a second branch line to connect the radiator with the electrical device through the fifth valve.