Vehicle thermal management system

A vehicle thermal management system comprising:

• a first refrigerant circuit including a first compressor that compresses first refrigerant and circulates the first refrigerant in the first refrigerant circuit, a first refrigerant/inside air heat exchanger that exchanges heat between the first refrigerant and inside air supplied into a vehicle interior, and a first expansion valve, the first refrigerant circuit being configured to perform air conditioning of the vehicle interior;
• a cooling water circuit including a water pump that circulates cooling water in the cooling water circuit, the cooling water circuit being configured to cool an in-vehicle electric component;
• a second refrigerant circuit including a second compressor that compresses second refrigerant and circulates the second refrigerant in the second refrigerant circuit, a second refrigerant/outside air heat exchanger that exchanges heat between the second refrigerant and outside air, and a second expansion valve, the second refrigerant circuit being configured to control a temperature of an in-vehicle battery;
• a first refrigerant/cooling water heat exchanger connected to the first refrigerant circuit and the cooling water circuit, the first refrigerant/cooling water heat exchanger being configured to exchange heat between the first refrigerant and the cooling water;
• a second refrigerant/cooling water heat exchanger connected to the second refrigerant circuit and the cooling water circuit, the second refrigerant/cooling water heat exchanger being configured to exchange heat between the second refrigerant and the cooling water;
• and
• a control unit configured to control operations of the first refrigerant circuit, the cooling water circuit, and the second refrigerant circuit, wherein
• the first refrigerant circuit, the cooling water circuit, and the second refrigerant circuit operate in a two-stage heat pump mode where the vehicle interior is heated, by a control of the control unit,
• in the first refrigerant circuit in the two-stage heat pump mode, the first refrigerant compressed by the first compressor dissipates heat into the inside air at the first refrigerant/inside air heat exchanger serving as a condenser in the first refrigerant circuit, the first refrigerant after dissipating the heat is reduced in pressure at the first expansion valve, the first refrigerant reduced in pressure absorbs heat from the cooling water at the first refrigerant/cooling water heat exchanger serving as an evaporator in the first refrigerant circuit,
• in the cooling water circuit in the two-stage heat pump mode, the cooling water circulating in the cooling water circuit absorbs heat from the second refrigerant at the second refrigerant/cooling water heat exchanger and dissipates heat into the first refrigerant at the first refrigerant/cooling water heat exchanger, and
• in the second refrigerant circuit in the two-stage heat pump mode, the second refrigerant compressed by the second compressor dissipates heat into the cooling water at the second refrigerant/cooling water heat exchanger serving as a condenser in the second refrigerant circuit, the second refrigerant after dissipating the heat is reduced in pressure at the second expansion valve, and the second refrigerant reduced in pressure absorbs heat from the outside air at the second refrigerant/outside air heat exchanger serving as an evaporator in the second refrigerant circuit.