Waste heat recovery device

A waste heat recovery device comprising:

• a Rankine cycle including a working fluid circuit, the working fluid circuit including:
• a heater configured to heat and evaporate working fluid,
• an expander configured to expand the working fluid having passed through the heater to generate power,
• a condenser configured to condense the working fluid having passed through the expander, and
• a working fluid pump configured to feed, to the heater, the working fluid having passed through the condenser,
• wherein the heater, the expander, the condenser and the working fluid pump are sequentially arranged;
• a first coolant water circuit configured to circulate coolant water by way of an internal combustion engine and a radiator;
• a second coolant water circuit configured to circulate the coolant water by way of the internal combustion engine and a first branched path branched between the internal combustion engine and the radiator;
• and
• a third coolant water circuit configured to circulate the coolant water by way of the radiator and a second branched path branched between the first branched path and the radiator, wherein
• a heat source of the heater is waste heat of the internal combustion engine,
• the condenser is a heat exchanger configured to exchange heat between the working fluid and the coolant water of the third coolant water circuit, and
• a check valve configured to prevent a backflow of the coolant water toward the radiator is provided between the first branched path and the second branched path on a downstream side of the radiator in the first coolant water circuit.