Water Electrolysis Cell Purging for Reliable Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing water electrolysis and electricity generating systems face challenges in smoothly and reliably switching between water electrolysis mode and electricity generating mode, leading to inefficiencies and increased system complexity.
Innovation Solution
The system incorporates a method that includes a cell member with an MEA, fluid flow paths, and a gas-liquid separator, allowing for efficient purging and water management to facilitate seamless mode switching, with the oxygen-containing gas used for both purging and humidification, and shared flow paths to reduce system size and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate flow paths are used for water supply and purging operations, then the reliability of mode switching is improved, but the device complexity and system size increase
Solution Approach 1:
The patent implements a dual-function flow path design where the supply flow path serves both water supply during electrolysis mode and purging gas transport during electricity generation mode. The flow path is equipped with switching valves that redirect the flow based on operational mode, allowing one physical path to fulfill multiple functions and reducing overall system complexity while maintaining switching reliability.
Solution Approach 2:
The system employs dynamically switchable flow paths using valves that can redirect fluid flow based on operational requirements. During electrolysis mode, the supply flow path transports water; during electricity generation mode, the same path transports purging gas. This dynamic reconfiguration allows the system to adapt its flow paths to current operational needs, reducing the need for permanent separate paths.
2Ease of operation
If dedicated purging flow paths are implemented, then the ease of operation during mode switching is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The purging flow path is designed to share infrastructure with the water supply flow path, using common components such as the supply flow path, inlet port member, and gas-liquid separator. By making these components multi-functional, the system achieves ease of operation during mode switching without requiring separate dedicated paths, thereby reducing manufacturing complexity and cost.
Solution Approach 2:
The patent merges the water supply flow path and purging gas flow path into a unified infrastructure. The supply flow path physically combines water transport and gas purging functions, and the gas-liquid separator handles both water electrolysis output and purging gas output. This merging reduces the total number of components needed while maintaining operational simplicity.
3Device complexity
If the oxygen-containing gas flow path is shared with the purging operation, then the device complexity is reduced, but the risk of electrolyte membrane drying increases
Solution Approach 1:
The system performs preliminary humidification of the purging gas by passing it through the oxygen-containing gas flow path, which contains humidified gas from the electrolysis process. This preliminary action ensures that the gas used for purging is already humidified before it contacts the electrolyte membrane, preventing membrane drying while still allowing the sharing of the oxygen-containing gas flow path.
Solution Approach 2:
The oxygen-containing gas acts as an intermediary medium that transfers humidity from the electrolysis process to the purging operation. By using this intermediary gas flow path, the system can share infrastructure between electrolysis and purging functions while protecting the electrolyte membrane from drying through indirect humidification.
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 enables reliable switching between modes, reduces system complexity and cost by utilizing shared flow paths, and prevents drying of the electrolyte membrane, thereby stabilizing electricity generation and extending component lifespan.
Implementation Method 1
a gas-liquid separator that separates into a gas and a liquid the gas-containing water that is guided from the lead-out flow path
Implementation Method 2
the water supplied to the first electrode is electrolyzed to thereby generate product hydrogen gas at the second electrode
Implementation Method 3
electricity is generated by an electrochemical reaction that takes place between the oxygen-containing gas supplied to the first electrode and the hydrogen gas supplied to the second electrode
Data Source
AI summary
A method of operating a water electrolysis and electricity generating system includes, at a time of switching from the water electrolysis mode to the electricity generating mode, a water electrolysis stopping step, a purging step and an electricity generation starting step. In the purging step after the water electrolysis stopping step, an oxygen-containing gas is caused to flow from an oxygen-containing gas flow path to a first gas-liquid separator via an oxygen-containing gas introduction flow path, a first supply flow path, a first inlet port member, a first fluid flow path, a first outlet port member, and a first lead-out flow path. In the electricity generation starting step after the purging step, the cell member is caused to generate electricity based on a predetermined required load value.