Anode End Fuel Cell Channel Depth for Cold Start Starvation
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Solution Overview
Problem
Fuel starvation at the anode end of a fuel cell stack during cold boot strap starts is exacerbated by ice formation, leading to poor performance and carbon corrosion, with existing solutions being costly, time-consuming, and unsuitable for vehicular applications.
Innovation Solution
Deepening the fuel flow field channels at the anode end of the fuel cell stack by 35% to 65% compared to other cells ensures sufficient fuel flow, preventing starvation while minimizing ice accumulation and reducing carbon corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the fuel flow field channel depth at the anode end is increased, then fuel flow to the anode end cell is improved, but the device complexity increases
Solution Approach 1:
The patent applies local quality by making the fuel flow field channels at the anode end specifically deeper than channels in other cells. This localized modification targets the specific problem area (anode end fuel starvation) without requiring uniform changes throughout the entire stack, thus improving fuel delivery where needed while limiting the overall structural complexity increase.
Solution Approach 2:
The fuel cell stack is segmented into different regions with different channel depths - the anode end cell has deeper channels while other cells maintain standard channel depths. This segmentation allows the system to address the specific fuel starvation problem at the anode end without unnecessarily complicating the design of the entire stack.
2Reliability
If deep fuel flow field channels are used at the anode end, then fuel starvation is avoided, but ice accumulation may increase
Solution Approach 1:
The patent changes the geometric parameter of the fuel flow field channels (increasing depth) at the anode end to improve fuel delivery. This parameter change creates a volume effect where the deeper channels provide sufficient fuel flow that can prevent or reduce ice blockage by maintaining better fuel supply to the catalyst layer during cold startup conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively eliminates fuel starvation and reduces carbon corrosion at the anode end during cold starts, enhancing overall performance without increasing ice blockage, making it suitable for vehicular fuel cell power plants.
Implementation Method 1
providing the fuel reactant flow field channel depth of the anode end cell to be significantly deeper than the depth of fuel reactant flow field channels in all of the other cells of the stack... This results in the elimination of fuel starvation in the anode end cell
Data Source
Figure 1
AI summary
The fuel flow channels (20a) of the end fuel cell (9a) at the anode end (34) of a fuel cell stack are significantly deeper than the fuel flow field channels (20) of the remaining fuel cells (9) in the stack, whereby fuel starvation caused by ice in the fuel flow channels is avoided during cold startup. The fuel flow field channels of the end cell (9) at the anode end of the stack is between about 0.15 mm and about 1.5 mm deeper than the fuel flow field channels in the remaining fuel cells of the stack, or between about 35% and about 65% deeper than the fuel flow field channels in the remaining fuel cells of the stack.