Battery Housing Degassing Vent With Particle-Retaining Grid

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Solution Overview

Problem

Existing degassing units for electronics housings, particularly battery housings in motor vehicles, fail to effectively retain hot particles and flammable gases during cell defects, leading to potential fires and vehicle damage due to excessive pressure loss during emergency degassing.

Innovation Solution

A degassing unit with a semi-permeable membrane and a separation grid that maintains hot particles and flammable gases within the housing, utilizing a membrane support device and a separation grid with distinct distances from the membrane to minimize pressure loss and maximize particle retention, ensuring the separation grid's area is larger than the gas passage opening to prevent clogging and retain over 75% of particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a semipermeable membrane is used for pressure equalization, then gas exchange is enabled and liquid ingress is prevented, but hot particles can escape unretained during cell defects

Engineering Contradiction:
Improvepressure equalizationVSAvoidhot particle escape
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The degassing unit is segmented into multiple functional layers: a semipermeable membrane for pressure equalization, a membrane support device for structural stability, and a separation grid for particle retention. Each layer performs a specific function, collectively resolving the contradiction between allowing gas exchange and retaining hot particles.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The separation grid acts as an intermediary element between the membrane and the external environment. It mediates the conflict by allowing gas to pass through while intercepting and retaining hot particles that would otherwise escape through the membrane opening.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the separation grid area is increased to retain particles, then particle retention efficiency improves, but pressure loss during emergency degassing increases

Engineering Contradiction:
Improveparticle retentionVSAvoidpressure loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The separation grid features locally varied properties: the grid bar diameter and spacing are optimized to provide sufficient particle retention while maintaining adequate open area for gas flow. The grid opening area ratio is specifically designed to balance retention efficiency with pressure loss minimization.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention optimizes critical parameters of the separation grid, including grid opening area ratio, grid bar diameter, and spacing between grid bars. These parameter changes enable the grid to retain particles effectively while minimizing pressure loss during emergency degassing events.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the separation grid is placed close to the membrane, then particle retention is maximized, but the grid may clog the gas passage opening

Engineering Contradiction:
Improveparticle retentionVSAvoidgas exchange efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The separation grid is positioned in a spatial arrangement that extends beyond the simple plane of the membrane. By considering the three-dimensional configuration and spacing, the grid captures particles effectively while maintaining sufficient clearance for gas flow paths.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Strength

If a membrane support device is added to support the membrane, then membrane stability improves, but device complexity increases

Engineering Contradiction:
Improvemembrane stabilityVSAvoidstructural complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The membrane support device is merged with the separation grid structure, combining two functions into a single integrated component. This reduces overall device complexity while maintaining both membrane stability and particle retention capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The separation grid serves multiple functions simultaneously: it provides structural support to the membrane, retains hot particles, and minimizes pressure loss. This multi-functionality reduces the need for separate components, thereby simplifying the overall device structure.

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

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 solution effectively retains hot particles and flammable gases, reducing the risk of fires and maintaining housing integrity by minimizing pressure loss and ensuring efficient particle separation, even under high thermal conditions.

Implementation Method 1

a gas passage opening covered by a semipermeable membrane which allows passage of gaseous media from an environment into the electronics housing and vice versa, but prevents passage of liquid media and solids

Methodology Applied
Scientific EffectSemipermeable membrane permeation: Semipermeable Membrane

Implementation Method 2

which at least partially overlaps the gas passage opening and is located at a first distance from the semipermeable membrane... arranged on an inside of the base body at a second distance from the semipermeable membrane, which is greater than the first distance

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Data Source

PatentEP3916899B1Degassing unit and electronics enclosure, in particular battery housing
Publication Date: 2025.01.08 MANN HUMMEL GMBH
  • EP3916899B1 patent drawingFigure 1~2
  • EP3916899B1 patent drawingFigure 3~4
  • EP3916899B1 patent drawingFigure 5~6

AI summary

The invention relates to a degassing unit (10) for an electronics housing, in particular for a battery, especially for a traction battery of a motor vehicle, which has a base body (1) that can be connected in a fluid-tight manner to an edge of a pressure equalization opening of the electronics housing and which has at least one gas passage opening (15) covered by a semipermeable membrane (6). The membrane allows the passage of gaseous media from the environment into the electronics housing and vice versa, but prevents the passage of liquid media and/or solids. Furthermore, the degassing unit (10) has a membrane support device (2) on an inner surface (17) of the base body (1), which at least partially overlaps the gas passage opening (15) and is located at a first distance from the semipermeable membrane (6).At a second distance from the semipermeable membrane (6), which is greater than the first distance, a separating grid (8) with a plurality of grid openings (81) is arranged on an inner surface (17) of the base body (1), which completely covers the gas passage opening (15). Furthermore, an electronics housing with a degassing unit (10) according to the invention is disclosed.