Integrated Fuel Cell Humidifier Water Separator

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing treatment devices for fuel cell exhaust gas require significant space and numerous components, leading to high installation costs and inefficiencies.

Innovation Solution

A treatment device with an integrated humidifier and water separator, where the outflow area has a larger cross-section than the inflow area, decelerating exhaust gas flow for efficient water separation, and utilizing gravity and density differences for additional separation within the humidifier itself, reducing the need for separate components and space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate water separator is provided downstream of the humidifier, then liquid water separation is improved, but device complexity and installation space increase

Engineering Contradiction:
Improveliquid water separationVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the water separator function directly into the humidifier housing, eliminating the need for a separate downstream water separator. The housing is designed with an expanded outflow area that serves dual purposes: as the exit for humidified air and as a water collection chamber. This merging of functions reduces the number of components while maintaining effective liquid water separation through the enlarged outflow area where water droplets can settle and be drained.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a separate water separator is provided downstream of the humidifier, then liquid water separation is improved, but installation space requirement increases

Engineering Contradiction:
Improveliquid water separationVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent combines the humidifier and water separator into a single integrated unit, where the housing serves both functions. The outflow area of the humidifier is expanded to create a water collection chamber within the same spatial envelope, eliminating the need for additional space for a separate downstream separator and reducing overall installation footprint.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The water separation function is nested within the humidifier housing structure. The collection area for liquid water is formed as an expansion of the outflow area, effectively nesting the water separator functionality inside the existing humidifier volume rather than adding external components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If the outflow area cross-section is enlarged to decelerate exhaust gas flow, then water separation efficiency is improved, but humidifier volume increases

Engineering Contradiction:
Improvewater separation efficiencyVSAvoidhumidifier volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The enlarged outflow area serves multiple functions simultaneously: it acts as the exit for humidified air, provides a deceleration zone for water droplet separation through reduced flow velocity, and forms a collection chamber for accumulated liquid water. This multi-functionality achieves effective water separation without requiring additional volume beyond what is needed for the expanded outflow area itself.

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

This configuration allows for efficient water separation with reduced pressure loss and installation space, lowering costs and improving the treatment device's functionality by integrating the humidifier and water separator, enabling effective humidification and water removal within a compact unit.

Implementation Method 1

Through off-gas inlets the off-gas is introduced into a hollow tube membrane bundle at a rear end of the humidifier. The off-gas then flows in counter-current to the air which passes through the hollow tube membranes.

Methodology Applied
Scientific EffectHumidification through membrane: Permeation

Implementation Method 2

an outflow area of the humidifier has a cross-section capable of being passed by the exhaust gas, which is larger than a cross-section of an inflow area of the humidifier capable of being passed. By enlarging the cross-section capable of being passed in the area of the humidifier serving for transferring humidity, a deceleration of the flow of the exhaust gas is achieved.

Methodology Applied
Scientific EffectFlow deceleration through area expansion: Bernoulli Effect

Implementation Method 3

a deceleration of the flow velocity of the exhaust gas, a particularly efficient separation of liquid water can be achieved in the outflow area

Methodology Applied
Scientific EffectGravity-based separation: Gravitation

Implementation Method 4

even within the distance from the inflow area to the outflow area and/or in the inflow area itself, efficient separation of liquid water with the aid of gravity and due to density differences is achievable.

Methodology Applied
Scientific EffectDensity difference separation: Density Gradient

Data Source

PatentEP3155683B1Treatment device for treating exhaust gas of a fuel cell stack, fuel cell system and vehicle with a fuel cell system
Publication Date: 2018.12.05 MERCEDES BENZ GROUP AG
  • EP3155683B1 patent drawingFigure 1

AI summary

The invention relates to a treatment device for treating exhaust gases of a fuel cell stack (16) of a fuel cell system (10). In a humidifier (12), in which the exhaust gas is usable for humidifying a medium capable of being introduced into the fuel cell stack (26), a water separator for reducing a content of liquid water in the exhaust gas is provided. Herein, the humidifier (12) and the water separator are integrated in a common constructional unit. An outflow area (28) of the humidifier (12) has a cross-section capable of being passed, which is larger than a cross-section of an inflow area (26) of the humidifier (12) capable of being passed. In the constructional unit, at least one collection area (36) for the liquid water separated upon exit from the outflow area (28) is provided. Furthermore, the invention relates to a fuel cell system (10) with such a treatment device as well as to a vehicle with a fuel cell system (10).