Vehicle heat management system

A vehicle heat management system comprising:

• a refrigerant circuit configured to compress, condense, expand and evaporate refrigerant and including a first refrigerant-heat medium heat exchanger, a first decompressor, a second refrigerant-heat medium heat exchanger, a second decompressor, and a third refrigerant-heat medium heat exchanger;
• and
• a heat medium circuit through which heat medium having been subjected to a heat exchange with the refrigerant in at least one of the first refrigerant-heat medium heat exchanger, the second refrigerant-heat medium heat exchanger, and the third refrigerant-heat medium heat exchanger circulates, wherein:
• the first refrigerant-heat medium heat exchanger functions as a condenser;
• the first decompressor is provided between the first refrigerant-heat medium heat exchanger and the second refrigerant-heat medium heat exchanger;
• the second refrigerant-heat medium heat exchanger is configured to selectively function as a condenser and an evaporator;
• the second decompressor is provided between the second refrigerant-heat medium heat exchanger and the third refrigerant-heat medium heat exchanger;
• the heat medium circuit includes a switch device configured to be able to switch between a circuit state in which the heat medium having passed through the second refrigerant-heat medium heat exchanger flows to the first refrigerant-heat medium heat exchanger and a circuit state in which a flow path of the heat medium having passed through the first refrigerant-heat medium heat exchanger and a flow path of the heat medium having passed through the second refrigerant-heat medium heat exchanger form individual circuits, respectively;
• and
• the switch device is configured to be able to switch to the circuit state in which the flow path of the heat medium having passed through the first refrigerant-heat medium heat exchanger and the flow path of the heat medium having passed through the second refrigerant-heat medium heat exchanger form individual circuits, respectively, when the first refrigerant-heat medium heat exchanger and the second refrigerant-heat medium heat exchanger both function as condensers.