Abstract: A power supply system of the embodiment includes a fuel cell which is able to generate power, a power storage device which stores the power generated by the fuel cell, a converter which converts power from the fuel cell or the power storage device and switches between supply of power from the fuel cell to an auxiliary device and supply of power from the power storage device to the auxiliary device, and a controller which controls at least the switching of the converter.

Abstract: A method for cleaning a radiator of a vehicle, includes stopping the vehicle that includes a fuel cell through which a coolant is to pass. Electric power in the fuel cell is generated to raise a temperature of the coolant while stopping the vehicle. The coolant is circulated from the fuel cell to a radiator while stopping the vehicle. The coolant flowing from the radiator is supplied to an ion exchanger to remove ions from the coolant while stopping the vehicle.

Abstract: A method for cleaning a radiator of a vehicle, includes stopping the vehicle that includes a fuel cell through which a coolant is to pass. Electric power in the fuel cell is generated to raise a temperature of the coolant while stopping the vehicle. The coolant is circulated from the fuel cell to a radiator while stopping the vehicle. The coolant flowing from the radiator is supplied to an ion exchanger to remove ions from the coolant while stopping the vehicle.

Abstract: A waste heat recovery system includes a fuel cell, a coolant circulation flow passage, a first heat exchanger, a waste heat recovery flow passage, a second heat exchanger, an upstream end of the waste heat recovery flow passage, and a downstream end of the waste heat recovery flow passage. The coolant circulation flow passage includes a first coolant supply flow passage, a first coolant exhaust flow passage, and a first bypass flow passage. The upstream end is connected to at least one of an inlet coolant reservoir and the first coolant exhaust flow passage at a position downstream of a connection point between the first coolant exhaust flow passage and the first bypass flow passage. The downstream end is connected to at least one of the inlet coolant reservoir, an outlet coolant reservoir, and the first coolant supply flow passage.

Abstract: A waste heat recovery system includes a fuel cell, a coolant circulation flow passage, a first heat exchanger, a waste heat recovery flow passage, a second heat exchanger, an upstream end of the waste heat recovery flow passage, and a downstream end of the waste heat recovery flow passage. The coolant circulation flow passage includes a first coolant supply flow passage, a first coolant exhaust flow passage, and a first bypass flow passage. The upstream end is connected to at least one of an inlet coolant reservoir and the first coolant exhaust flow passage at a position downstream of a connection point between the first coolant exhaust flow passage and the first bypass flow passage. The downstream end is connected to at least one of the inlet coolant reservoir, an outlet coolant reservoir, and the first coolant supply flow passage.

Abstract: A coolant composition for a fuel cell unit, which contains at least one aliphatic alcohol having unsaturated bonds in the molecules having 2 to 20 carbon atoms each. The coolant composition maintains the electrical conductivity of the coolant at 10 ?S/cm or below as well as the fluctuation of the electrical conductivity within the range of 0 to 10 ?S/cm.

Abstract: The present invention relates to a coolant composition for fuel cell coolant, comprised of sulfur containing alcohol or sulfur containing phenol having at least one sulfur atom per molecule, which effectively prevents increase of electric conductivity due to oxidation of its base component for a long time. The coolant composition when diluted with water to a predetermined concentration effectively suppresses increase of electric conductivity of the coolant and maintain fluctuation of electric conductivity within the range from 0 to 10 ?S/cm so that power generation efficiency of the fuel cell may not be lowered.