Vehicle air-conditioning device

A vehicle air-conditioning device having a vehicle-cabin radiator for heating air guided into a vehicle cabin of a vehicle, comprising:

• a first coolant-water circulation path in which coolant water passes through an engine;
• a second coolant-water circulation path communicated with the first coolant-water circulation path and in which the coolant water passes through the vehicle-cabin radiator;
• a shutting off mechanism configured to, when switched to a shut-off state, shut off communication between the first coolant-water circulation path and the second coolant-water circulation path;
• and
• a refrigeration cycle having a compressor configured to compress cooling medium, a secondary evaporator configured such that the cooling medium in the secondary evaporator absorbs heat from the coolant water in the first coolant-water circulation path, a secondary condenser configured to release heat of the cooling medium that has absorbed the heat at the secondary evaporator to the coolant water in the second coolant-water circulation path, and a secondary expander configured to decompress the cooling medium that has passed through the secondary condenser,
• a radiator configured to perform heat exchange with the secondary evaporator and which is provided in the first coolant-water circulation path, and
• a heat absorber configured to perform heat exchange with the secondary condenser and which is provided in the second coolant-water circulation path.