Water Electrolysis Apparatus Differential Pressure Control

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Solution Overview

Problem

Existing water electrolysis apparatuses face challenges in appropriately reducing differential pressure on the electrolytic membrane, which can lead to membrane breakage and gas mixing.

Innovation Solution

A water electrolysis apparatus with an electrolytic membrane using ion-permeable membranes, controlled by a computer system that adjusts the opening degrees of pressure control valves based on feedback and feedforward control mechanisms to manage differential pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional pressure control methods are used to maintain differential pressure, then gas separation is maintained, but differential pressure on the electrolytic membrane is not sufficiently reduced, risking membrane breakage

Engineering Contradiction:
Improveelectrolytic membrane integrityVSAvoiddifferential pressure on membrane
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary action by controlling the opening degrees of pressure control valves in advance based on predicted differential pressure, preventing excessive pressure buildup before it occurs. The computer calculates required valve openings proactively to maintain differential pressure within safe limits, rather than merely reacting to pressure changes after they occur.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback control by continuously monitoring the differential pressure between oxygen and hydrogen sides and using this information to adjust the opening degrees of pressure control valves. The computer receives differential pressure data and dynamically modifies valve positions to maintain pressure balance, ensuring the electrolytic membrane is protected from excessive stress.

Inventive Principle:
Principle #23Feedback

2Reliability

If pressure control valves are adjusted to reduce differential pressure, then membrane breakage is prevented, but control system complexity increases

Engineering Contradiction:
Improveelectrolytic membrane integrityVSAvoidcontrol system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The computer system performs multiple functions: it calculates differential pressure, determines required valve opening degrees, controls both oxygen and hydrogen pressure control valves, and monitors system status. This multi-functionality consolidates what would otherwise require separate control mechanisms into a single integrated control unit, managing complexity through functional consolidation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system manages complexity by focusing control on key parameters - specifically the opening degrees of pressure control valves - rather than attempting to control all system variables. By changing these critical parameters based on differential pressure feedback, the system achieves effective pressure management with a relatively simple control approach.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If differential pressure is reduced to prevent membrane breakage, then membrane safety is improved, but gas mixing risk increases

Engineering Contradiction:
Improveelectrolytic membrane integrityVSAvoidgas mixing between oxygen and hydrogen
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system employs dynamic control by continuously adjusting the opening degrees of pressure control valves based on real-time differential pressure conditions. Rather than maintaining a fixed pressure differential, the system dynamically modulates valve positions to keep differential pressure within a safe range, adapting to changing operational conditions while preventing both membrane breakage and gas mixing.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The computer controls the opening degrees of pressure control valves as adjustable parameters to maintain differential pressure within an optimal range. By dynamically changing these valve opening parameters, the system achieves a balance between reducing membrane stress and preventing gas mixing, optimizing both safety and separation effectiveness.

Inventive Principle:
Principle #35Parameter changes

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

The apparatus effectively reduces differential pressure, preventing membrane breakage and gas mixing, while maintaining efficient gas separation and electrolysis performance.

Implementation Method 1

water electrolysis apparatuses that electrolyze water, using an electrolytic membrane and generate oxygen and hydrogen on one surface side and the other surface side of the electrolytic membrane, respectively

Methodology Applied
Scientific EffectIon permeation: Permeation

Implementation Method 2

controlled by a computer system that adjusts the opening degrees of pressure control valves based on feedback and feedforward control mechanisms

Methodology Applied
Scientific EffectFeedback control: Feedback

Data Source

PatentEP3839101B1Water electrolysis apparatus
Publication Date: 2025.06.25 ASAHI KASEI KOGYO KABUSHIKI KAISHA
  • EP3839101B1 patent drawingFigure 1
  • EP3839101B1 patent drawingFigure 2~3
  • EP3839101B1 patent drawingFigure 4

AI summary

Control of an opening degree of the oxygen pressure control valve (21) includes first feedback control for controlling the opening degree of the oxygen pressure control valve (21), based on tank internal pressure detected by the first tank internal pressure detector (22) in such a way that a difference between the tank internal pressure and a predetermined target pressure decreases and first feedforward control for controlling the opening degree of the oxygen pressure control valve (21), based on current detected by the current detector (15). Control of an opening degree of the hydrogen pressure control valve (26) includes second feedback control for controlling the opening degree of the hydrogen pressure control valve (26), based on tank internal pressure detected by the second tank internal pressure detector (27) in such a way that a difference between the tank internal pressure and a predetermined target pressure decreases and second feedforward control for controlling the opening degree of the hydrogen pressure control valve (26), based on current detected by the current detector (15).