Regenerative Fuel Cell Depressurization via Bypass Gas Consumption
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Solution Overview
Problem
The existing regenerative fuel cell systems face challenges in accurately controlling the depressurization rate due to fluctuations in primary and secondary pressures of flow regulating valves, leading to gas cross-leaking and discharge, and complex timing control of on-off valves, resulting in gas loss and inefficiency.
Innovation Solution
A regenerative fuel cell system with a control device that manages depressurization by setting supply pressure reducing valves lower than bypass pressure reducing valves, allowing gas to be supplied via bypass paths to the fuel cell for consumption, thereby controlling the depressurization process effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If flow regulating valves are used to control depressurization rate, then gas can be supplied to fuel cell, but pressure fluctuations cause inaccurate control and gas cross-leaking
Solution Approach 1:
The patent replaces the mechanical flow regulating valves with an electrochemical approach by utilizing the fuel cell itself to consume the gas during depressurization. The fuel cell operates in reverse mode, consuming hydrogen and oxygen to generate electricity, thereby controlling pressure reduction without mechanical moving parts that cause fluctuations and leakage.
2Ease of operation
If on-off valves are controlled to manage depressurization timing, then gas supply can be regulated, but complex timing control leads to operation complexity
Solution Approach 1:
The patent extracts the timing control function from the valve system and transfers it to the control device that manages fuel cell operation. By controlling when the fuel cell consumes gas, the system achieves precise depressurization timing without complex valve coordination, simplifying the overall control architecture.
3Productivity
If depressurization is executed without consuming gas in fuel cell, then depressurization speed increases, but gas is discharged to exterior causing loss
Solution Approach 1:
The patent converts the previously harmful gas discharge to the exterior into a beneficial process by having the fuel cell consume the gas during depressurization. The gas that would have been wasted is now utilized to generate electricity, simultaneously achieving rapid depressurization and preventing gas loss while producing useful energy.
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 ensures precise control of the depressurization rate, prevents gas cross-leaking, and enhances the efficiency of the system by ensuring continuous power generation.
Implementation Method 1
a fuel cell configured to carry out power generation by an electrochemical reaction between oxygen gas and hydrogen gas
Implementation Method 2
a compression device configured to generate either one of a pressurized oxygen gas or a pressurized hydrogen gas
Implementation Method 3
a supply pressure reducing valve disposed in the gas supply path between the tank and the merging portion, a bypass pressure reducing valve disposed in the bypass path
Data Source
AI summary
When executing a depressurizing process of a hydrogen compression device and a water electrolysis device, on-off valves that supply a hydrogen gas or an oxygen gas to a fuel cell are placed in an opened state, and further, a set pressure of supply pressure reducing valves are adjusted to a value that is lower than a set pressure of bypass pressure reducing valves. Gas remaining in gas depressurizing regions is supplied, via the bypass pressure reducing valves, to the fuel cell.