Anode Gas Recirculation Valve for Fuel Cell Jet Pump Backflow

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Solution Overview

Problem

Existing fuel cell systems face challenges in recirculating anode gas, particularly with jet pumps, where fresh hydrogen cannot be added without activating recirculation, and there is a decrease in recirculation performance during partial load, leading to pressure losses and backflow issues.

Innovation Solution

A device with an actively controllable valve and magnet assembly allows for the introduction of fresh hydrogen without recirculation and prevents backflow by deactivating jet pumps in parallel, using a simple and inexpensive switching valve design that maintains tightness and avoids ignition sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a jet pump is used for recirculation, then recirculation can be achieved, but fresh hydrogen cannot be added without activating recirculation and recirculation performance decreases in partial load range

Engineering Contradiction:
Improverecirculation performanceVSAvoidability to add fresh hydrogen
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The inlet is segmented into a first inlet for recirculated anode gas and a second inlet for fresh hydrogen, allowing independent control of recirculation and fresh hydrogen addition. This enables fresh hydrogen to be added without activating recirculation, resolving the contradiction between recirculation performance and adaptability.

Inventive Principle:
Principle #1Segmentation

2Productivity

If a smaller second jet pump is used for partial load range, then recirculation performance in partial load is improved, but backflow occurs through the inactive first jet pump causing pressure loss

Engineering Contradiction:
Improverecirculation performance in partial loadVSAvoidpressure loss from backflow
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

Check valves are installed in parallel to each jet pump to prevent backflow through the inactive pump before it can cause pressure losses. This preliminary protective measure eliminates the harmful backflow effect while maintaining the benefits of having multiple jet pumps for different load ranges.

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If an integrated check valve is used to block backflow, then backflow is prevented, but pressure loss increases reducing recirculation performance

Engineering Contradiction:
Improveprevention of backflowVSAvoidrecirculation performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Instead of using a single check valve in series that causes pressure loss, the system segments the check valves and places them in parallel to each jet pump inlet. This configuration prevents backflow through the inactive pump while minimizing pressure losses, as each check valve only needs to handle the flow for its corresponding pump.

Inventive Principle:
Principle #1Segmentation

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

Enables efficient recirculation of anode gas with the ability to add fresh hydrogen and prevent backflow, maintaining performance across load ranges while minimizing pressure losses and ensuring hydrogen tightness.

Implementation Method 1

The valve comprises a magnet assembly for acting on a magnet armature

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

at least one jet pump with a propulsion nozzle for introducing fresh anode gas

Methodology Applied
Scientific EffectJet propulsion: Jet

Data Source

PatentEP4320354B1Device for recirculating anode gas in an anode circuit of a fuel cell system, fuel cell system
Publication Date: 2024.12.04 ROBERT BOSCH GMBH
  • EP4320354B1 patent drawingFigure 1
  • EP4320354B1 patent drawingFigure 2
  • EP4320354B1 patent drawingFigure 3

AI summary

Disclosed is a device (1) for recirculating anode gas in an anode circuit (11) of a fuel cell system (10), comprising at least one jet pump (2) with a propelling nozzle (3) for introducing fresh anode gas, preferably hydrogen, an inlet (4) for recirculated anode gas, and an outlet (5) for fresh and recirculated anode gas; an actively controllable valve (6) for closing and opening the inlet (4) is arranged in the area of the inlet (4), said valve (6) comprising a magnet assembly (7) for acting on a reciprocating armature (8), and a valve spring (9). Also disclosed is a fuel cell system (10) comprising a device (1) of said kind.