A thermal management system of a ship composite energy power system and a control method thereof are provided, including a thermal management circuit, which includes a seawater heat exchange circuit, an internal combustion engine thermal management circuit, a hydrogen fuel cell thermal management circuit, and a power battery and accessories thermal management circuit. It provides a thermal management control strategy for composite energy of internal combustion engine, fuel cell, and power battery; the various circuits can be independently adjusted; the heat dissipation effect is obvious, and the temperature of each cooling circuit can be better controlled; the energy utilization rate can be improved; the heat can be transferred to the other subsystems, and the heat dissipation area can be enlarged; and the fuel cell circuit can be elevated to the temperature by the heat exchanger and the electric heater, and it can reach the target working temperature more quickly.

A cooling water control apparatus controls a cooling apparatus having first pipe which circulates cooling water through an engine; second pipe which circulates cooling water not through the engine; a switching valve whose state is changed between opened and closed states; and a supplying mechanism which supplies cooling water, and has a determining device which determines whether there is failure of the switching valve based on difference between first temperature of cooling water in first pipe and second temperature of cooling water in second pipe after the command for changing the state of the switching valve from closed state to opened state is outputted; and a controlling device which controls the supplying mechanism to supply cooling water even after the engine stops, when the engine stops while the determining device determines whether there is failure of the switching valve.

A cooling apparatus comprises a first cooling conduit branching off from a downstream side connection conduit to cool the cylinder head, a second cooling conduit branching off from the downstream side connection conduit, is provided in parallel with the first cooling conduit, an intermediate cooling conduit being connected to the first and second cooling conduits, is provided with an EGR cooler, a third cooling conduit running from a connection point of the intermediate cooling conduit and the first cooling conduit to an upstream side connection conduit, a fourth cooling conduit running from a connection point of the intermediate cooling conduit and the second cooling conduit to the upstream side connection conduit, and a changeover valve for adjusting the flow resistance of the second cooling conduit. And the direction of coolant flow in the intermediate cooling conduit is changed over by operating the changeover valve.

An engine cooling device for a vehicle of the present invention includes: an engine cooling circuit that circulates a cooling liquid to an engine and a heat exchanger; a reservoir tank that is connected to the engine cooling circuit, and that stores the cooling liquid to absorb pressure changes within the engine cooling circuit; at least one or more cooling liquid circulating circuits that circulates the cooling liquid to devices installed in the vehicle; a switching section that selectively switches between either of a communicating state of communicating the engine cooling circuit and the cooling liquid circulating circuit, and a cut-off state of cutting-off the engine cooling circuit and the cooling liquid circulating circuit; and a control section that, in a case in which an ignition switch is turned off, controls the switching section such that the communicating state is set.