Advertisement
3.4.2 Stack degradation rate and lifetime
There are generally two key life-limiting failure modes that will prevent the stack
from performing as required in a given application: voltage loss and fuel leakage.
Voltage loss is seen as a steady degradation in maximum power. Fuel leakage will
lead to both an increase in fuel consumption, and H2 emissions in the coolant air
exhaust stream.
Testing has demonstrated that the H-1000XP stack has a mean lifetime of
approximately 1000 hours and 300 on/off cycles under nominal operating
conditions In general, to maximize stack life, avoid the following conditions:
• Fuel starvation (for example, due to low/high hydrogen pressure, or operating for
significant periods of time below optimal ambient temperature)
• High operating temperatures (operating for significant periods of time above
optimal ambient temperature)
• Contaminants in the coolant/oxidant air
• Contaminants in the fuel
• Open storage. When the stack is stored over a long period of time in a dry condition
(in air conditioned room). The MEA will be dehydrated and performance of the fuel cell
will decrease. Please store the stack in an airtight container when not in use.
3.4.3 Peak power output
The H-1000XP can deliver a peak power output of 1200W* to meet the high power
requirements during vehicle climbing hills. This is realized by connecting an ultra
capacitor in parallel hybrid configuration. Fuel cell also recharges the capacitor
when excess power is available during cruise.
Please refer to section 2.0 for more details of ultra capacitor
23
Advertisement
