Fuel Cell Stack Coolant Flow Guide Members for Temperature Uniformity
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Solution Overview
Problem
Conventional fuel cell stacks face challenges in maintaining uniform temperature distribution, particularly in cold weather, leading to reduced performance and durability due to temperature variations and flooding issues, which existing solutions address with thick insulators, heaters, and complex control systems.
Innovation Solution
The fuel cell stack incorporates coolant flow guide members, such as vanes, in the coolant inlet and outlet manifolds to recirculate coolant from high temperature cells to low temperature cells adjacent to the end plate, ensuring improved temperature uniformity without the need for additional insulation, heaters, or complex control systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If thick insulators are added to maintain temperature uniformity, then temperature distribution is improved, but stack thickness increases
Solution Approach 1:
The patent uses coolant flow dynamics (hydraulics) to achieve temperature uniformity. By strategically directing coolant flow through specific cells using guide members, the system balances temperature distribution without adding thermal insulation layers, thus avoiding increased stack thickness.
Solution Approach 2:
The patent changes the coolant flow parameters (flow rate distribution, flow path) to different cells based on their temperature conditions. By adjusting which cells receive coolant and at what flow rates, temperature uniformity is achieved through operational parameter optimization rather than structural modification.
2Temperature
If heaters are added to maintain temperature uniformity, then temperature distribution is improved, but device complexity increases
Solution Approach 1:
The system uses the coolant itself to perform the heating function by redirecting it through specific cells. The coolant, which has absorbed heat from other cells, naturally serves as the heat source for colder cells, eliminating the need for separate heating devices and reducing system complexity.
Solution Approach 2:
The patent merges the cooling and heating functions into a single coolant circulation system. The same coolant that cools hot cells simultaneously heats cold cells through strategic flow direction, combining multiple thermal management functions into one integrated system.
3Temperature
If complex control systems are added to maintain temperature uniformity, then temperature distribution is improved, but device complexity increases
Solution Approach 1:
The coolant flow guide members are designed to automatically direct coolant flow based on temperature conditions without requiring external control. The system self-regulates temperature distribution through passive flow direction mechanisms, eliminating complex control electronics and sensors.
Solution Approach 2:
The patent introduces dynamic flow direction capabilities through movable or adjustable guide members that can adapt coolant distribution in response to changing operating conditions, achieving temperature uniformity through dynamic flow management rather than static control systems.
4Temperature
If coolant flow is increased to cool cells, then temperature control is improved, but energy loss increases
Solution Approach 1:
The patent converts the wasted thermal energy in the coolant into a useful resource by directing it to heat cold cells. The coolant's thermal energy, which would otherwise be lost to the environment, is reused to balance temperature distribution, turning an energy loss into a beneficial heating source.
Solution Approach 2:
The coolant serves multiple functions simultaneously: it cools hot cells, heats cold cells, and maintains overall temperature uniformity. This multi-functionality maximizes the utility of the coolant and minimizes energy waste by ensuring thermal energy is utilized throughout the stack.
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 reduces temperature variation across the fuel cell stack, enhancing performance and durability by efficiently distributing heat energy from high temperature cells to low temperature cells, thus maintaining optimal operating conditions without increasing stack thickness or requiring external power sources.
Implementation Method 1
coolant from the coolant inlet manifold is guided into the first predetermined cell... flows through the coolant channel of the first predetermined cell to the coolant inlet manifold, wherein the coolant is then guided by the second coolant guide member to flow into the second predetermined cell... back to the coolant outlet manifold
Data Source
AI summary
The present invention provides a fuel cell stack which can reduce variation in temperature distribution of whole cells by a simple change in the structure of a coolant inlet manifold and a coolant outlet manifold in the fuel cell stack without the use of a conventional insulator, which increases the thickness of the fuel cell stack, a heater, which requires a power supply and its control logic, or a cover for forming an air layer for thermal insulation, which disadvantageously prevents the heat generated in the electrode from being transferred to the end plate. The invention provides a fuel cell stack with improved temperature uniformity, comprising one or more coolant flow guide members positioned within a coolant outlet manifold and/or a coolant inlet manifold, which causes coolant present in the coolant outlet manifold to be recirculated to the coolant inlet manifold and then back through one or more predetermined cells adjacent to the end plate to the coolant outlet manifold, thereby providing uniformity in the heat of the fuel cell stack.