1. Technical Field
Embodiments of the present invention generally relate to a system and method for delivering at least one fluid stream through a fuel cell stack.
2. Background Art
It is generally well known that a number of fuel cells are joined together to form a fuel cell stack. Such a stack generally provides electrical current in response to electrochemically converting hydrogen and oxygen into water and energy. The electrical current is used to provide power for various electrical devices. A supply generally provides hydrogen to the fuel cell stack. The fuel cell stack may use less hydrogen than provided by the supply to generate electrical power. An ejector receives unused hydrogen discharged from the fuel cell stack and combines the unused hydrogen with the hydrogen generated from the supply to sustain a flow of hydrogen to the fuel cell stack. The ejector presents the supply hydrogen with the unused hydrogen to the fuel cell stack. The recirculation of the unused hydrogen to the fuel cell stack may improve fuel efficiency.
The amount of flow of hydrogen that is passed through the fuel cell stack and needed to produce electrical current fluctuates based on the different levels of power consumption. In a high power consumption mode, the flow of the unused hydrogen discharged from the fuel cell stack is generally high since the fuel cell stack has to consume more hydrogen at a relatively faster rate in order to meet higher power demands.
During a low power consumption mode, it may be necessary to increase the flow of the hydrogen through the fuel cell stack since the fuel cell stack discharges unused hydrogen at a relatively slower flow rate. Such a slow flow rate of hydrogen may affect the life span of the fuel cell stack and affect the production of electrical power thereby leading to operational inefficiencies.
Accordingly, it would be desirable to provide a system and a method for determining when the vehicle is experiencing high and low power consumption modes and adjust the flow of the hydrogen that is presented to the fuel cell stack based on the consumption modes.