Abstract: The present invention relates to a cooling water supply system and a cooling water supply method for a fuel cell system in which a temperature difference in a fuel cell stack is prevented from increasing due to a rapid increase of a power output required in the stack by detecting a requested/demanded output. According to the present invention, a temperature difference in the stack due to a rapid increase in a power output demanded by the fuel cell stack is prevented from being rapidly increased by detecting a requested output (e.g., an amount an accelerator pedal is pushed, etc.) to calculate a power output required by the stack, calculating a predicted amount of generated heat depending on a required power output, and calculating a flux of supplied cooling water corresponding to the predicted amount of generated heat to control a flow rate of a cooling water supplier.

Abstract: The present invention relates to a fuel cell cooling system for a vehicle comprising: a cooling water circulating loop formed to cool a fuel cell stack where a plurality of fuel cells are stacked. The cooling water circulating loop includes: a plurality of cooling water introducing ports through which cooling water passing through the stack is introduced; a plurality of cooling water discharging ports corresponding to the plurality of cooling water introducing ports and through which the cooling water which has passed through the stack is discharged; and a plurality of cooling water channels connecting the plurality of cooling introducing ports and the plurality of cooling water discharging ports. Notably, cooling water flows in different directions in the plurality of cooling water channels.