Model based detection of hydrogen leaks in a fuel cell stack

Hydrogen leaks are potentially dangerous faults in fuel cell systems. The paper presents an approach to detect hydrogen leaks. The method is applicable during startup and shutdown as well as normal operating conditions. The method relies on simple mass balance equations but takes into account the natural leak of the stack and humidity. Hydrogen leak detection without using relative humidity sensors is specially studied. In that case, adaptive alarm thresholds are given so that false alarms due to the lack of humidity sensors are eliminated. The validity of the method is also discussed in terms of common hydrogen supply system configurations. The detection method is validated on an real fuel cell laboratory rig where leaks could be introduced in a controlled manner.