Membrane Humidifier Stack Frame for Sealing and Tolerance Compensation

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Solution Overview

Problem

Existing humidifiers for fuel cell systems face complex sealing issues and limited tolerance compensation, complicating assembly and efficiency in humidifying cathode supply air using cathode exhaust air.

Innovation Solution

A humidifier design featuring a membrane stack supported by a separate stack support frame that seals the membrane stack to the housing, allowing for simplified assembly and tolerance compensation, with air chambers and ducts arranged to prevent mixing of cathode supply and exhaust air while enabling moisture exchange.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple seals are used to seal the membrane stack in the housing, then sealing reliability is improved, but device complexity increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidsealing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the sealing function and support function into a single integrated stack support frame structure. The frame includes integrated sealing elements that directly seal against the housing, eliminating the need for separate seal components and reducing assembly complexity while maintaining reliable sealing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stack support frame serves multiple functions simultaneously: it provides structural support for the membrane stack, creates air chambers, and performs sealing against the housing. This multi-functional design reduces the number of components needed while ensuring reliable operation.

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

2Manufacturing precision

If traditional sealing methods are used, then sealing is achieved, but tolerance compensation is limited

Engineering Contradiction:
Improvetolerance compensationVSAvoidassembly complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The stack support frame incorporates flexible or adjustable elements that can adapt to manufacturing tolerances and dimensional variations. This dynamic capability allows the frame to compensate for tolerances between the membrane stack and housing, ensuring proper sealing and alignment without requiring extremely tight manufacturing tolerances.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If the membrane stack is directly sealed to the housing, then assembly is simple, but sealing reliability is insufficient

Engineering Contradiction:
Improveassembly simplicityVSAvoidsealing reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The stack support frame acts as an intermediary component between the membrane stack and the housing. It provides a dedicated sealing interface with integrated sealing elements that ensure reliable sealing while simplifying the assembly process. The frame mediates the connection, making assembly easier than direct sealing while ensuring better sealing reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Simplifies the sealing and assembly process, effectively humidifies cathode supply air using cathode exhaust air, and compensates for manufacturing tolerances, ensuring efficient operation of the fuel cell system.

Implementation Method 1

The membranes are airtight but permeable to water vapor, so that the cathode supply air and cathode exhaust air are separated by the membranes, yet the cathode supply air can still be humidified by the cathode exhaust air passing through the membranes.

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP4000721B1Humidifier
Publication Date: 2026.01.07 MAHLE INT GMBH
  • EP4000721B1 patent drawingFigure 1~2
  • EP4000721B1 patent drawingFigure 3~4
  • EP4000721B1 patent drawingFigure 5

AI summary

The invention relates to a humidifier (1) comprising a housing (2) with an interior space (5) and a membrane stack (3). The membrane stack (3) is permeable to cathode supply air (K-ZL) and cathode exhaust air (K-AL) without mixing and has two airtight sealed end faces (7a, 7b) and four airflow surfaces (8a, 8b, 8c, 8d). The membrane stack (3) is accommodated in the interior space (5) such that an air chamber (9a, 9b, 9c, 9d) is formed between each airflow surface (8a, 8b, 8c, 8d) and the housing (2). According to the invention, the humidifier (1) has a stack support frame (4), wherein the membrane stack (3) is inserted into the stack support frame (4) and the stack support frame (4) is inserted into the housing (2). The invention also relates to a membrane insert (6) for the humidifier (1) with the membrane stack (3) and the stack support frame (6).