Fuel cell system and warming up completion determining method for the same

摘要

A fuel cell system includes a fuel cell stack, a warming up status detector, a warming up completion threshold setter, an informing device, an estimator, and a threshold changer. The warming up status detector is configured to detect a warming up status of the fuel cell stack. The informing device is configured to inform of completion of warming up when a value corresponding to a warming up status detected by the warming up status detector is equal to or higher than a threshold value set by the warming up completion threshold setter. The estimator is configured to estimate whether generated water is frozen in the fuel cell stack. The threshold changer is configured to change the threshold value set by the warming up completion threshold setter in accordance with a freezing state of the generated water in the fuel cell stack estimated by the estimator.

主权项

1. A fuel cell system comprising:
a fuel cell stack configured to generate electric power using reactive gas supplied to the fuel cell stack; a warming up status detector configured to detect a warming up status of the fuel cell stack and including an activation timer configured to measure an activation time during which the fuel cell system is in operation and a temperature detector configured to detect a temperature in the fuel cell stack; a memory configured to record the activation time measured by the activation timer in a previous operation of the fuel cell system as a previous activation time and configured to record the temperature detected by the temperature detector in the previous operation of the fuel cell system as a previous operation temperature; a warming up completion threshold setter configured to set an integrated current threshold value and a temperature threshold value in order to determine completion of warming up of the fuel cell stack; an informing device configured to inform of completion of warming up when an integrated current value corresponding to the warming up status detected by the warming up status detector is equal to or higher than the integrated current threshold value set by the warming up completion threshold setter and when a temperature value corresponding to the warming up status detected by the warming up status detector is equal to or higher than the temperature threshold value set by the warming up completion threshold setter; an estimator configured to estimate whether generated water is frozen in the fuel cell stack on a basis of the previous activation time and the previous operation temperature, the estimator estimating that the generated water is frozen in the fuel cell stack if the previous activation time is equal to or shorter than a first estimation threshold and if the previous operation temperature is equal to or lower than a second estimation threshold; and a threshold changer configured to change, if the estimator estimates that the generated water is frozen in the fuel cell stack, the integrated current threshold value and/or the temperature threshold value set by the warming up completion threshold setter to extend a time period until the informing device informs of the completion of warming up, wherein, when the estimator determines that a low-temperature short-time operation was performed in the previous operation, the threshold changer changes the integrated current threshold value and the temperature threshold value, and wherein, when the estimator determines that a low-temperature short-time operation was not performed in the previous operation and was performed in the present operation, the threshold changer changes only the temperature threshold value and maintains the integrated current threshold value.