Anode Jet Pump Valve Control to Prevent Fuel Cell Return Flow

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Solution Overview

Problem

The existing recirculation systems for anode gas in fuel cell systems face challenges in adding fresh hydrogen without activating the recirculation process and preventing return flow through inactive jet pumps, especially in the partial load range, leading to reduced recirculation efficiency.

Innovation Solution

A device with an actively controllable valve using a magnet assembly and valve spring to control the inlet of the jet pump, allowing for the introduction of fresh hydrogen without recirculation and preventing return flow through inactive jet pumps by deactivating them, ensuring efficient recirculation and minimal pressure drop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a jet pump is used for recirculation, then recirculation is achieved, but fresh hydrogen cannot be added without activating recirculation

Engineering Contradiction:

Improveability to add fresh hydrogen independentlyVSAvoidrecirculation system control

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system separates the fresh hydrogen addition function from the recirculation function by introducing a bypass line with a separate control valve. This allows fresh hydrogen to be added to the anode circuit independently of the recirculation process, resolving the contradiction between adaptability and system complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A bypass line acts as an intermediary pathway between the hydrogen source and the anode circuit, allowing fresh hydrogen to be introduced without passing through the jet pump recirculation system. This mediator enables independent control of fresh hydrogen addition while maintaining the recirculation function through the jet pump.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If a smaller second jet pump is added for partial load range, then recirculation performance improves, but return flow through inactive jet pump increases

Engineering Contradiction:

Improverecirculation performance in partial load rangeVSAvoidpressure drop from return flow

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

Check valves are installed in each jet pump's flow path before operation to prevent reverse flow. This preliminary protective measure ensures that when one jet pump is inactive, its check valve blocks any potential return flow, eliminating energy losses while allowing multiple jet pumps to operate effectively in parallel across different load ranges.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If check valve is integrated to block return flow, then recirculation efficiency improves, but pressure drop increases

Engineering Contradiction:

Improveprevention of return flowVSAvoidpressure drop in anode circuit

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The system uses dynamically controllable valves instead of fixed check valves to control flow paths. By actively controlling valve openings based on operational requirements, the system maintains reliable flow direction control while minimizing pressure drops that would occur with constantly closed check valves. The dynamic adjustment allows optimal flow conditions during different operating states.

Inventive Principle:

Principle #15Dynamics

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 the addition of fresh hydrogen without activating the recirculation process and prevents return flow through inactive jet pumps, maintaining recirculation efficiency and reducing pressure drop, thus improving the overall performance of the fuel cell system.

Implementation Method 1

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

Methodology Applied

Scientific EffectMagnetic force: Magnetism

Implementation Method 2

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

Methodology Applied

Scientific EffectJet pump effect: Jet

Implementation Method 3

Given that only low differential pressures occur in the anode circuit, only a low actuator force is required

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentUS20240186544A1Device for recirculating anode gas in an anode circuit of a fuel cell system, and fuel cell system

Publication Date: 2024.06.06 ROBERT BOSCH GMBH

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 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.