Corrugated Heat Exchanger Plate Flattening for Welded Fuel Cell Joints

Solution Overview

Problem

Existing heat exchangers in fuel cell systems face challenges in forming reliable, fluid-tight connections due to the corrugated shape and low thickness of heat exchange plates, which often require expensive and low-throughput vacuum brazing processes.

Innovation Solution

A method involving flattening the opposing ends of a corrugated heat exchange plate to form thicker, flattened ends that can be reliably welded to structural components, eliminating the need for vacuum brazing and enhancing manufacturing capacity and throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vacuum brazing is used to connect corrugated heat exchange plates, then fluid-tight connections are achieved, but manufacturing cost increases and throughput decreases

Engineering Contradiction:

Improvefluid-tight connectionVSAvoidmanufacturing throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The heat exchange plate is divided into two distinct zones: a corrugated middle portion for heat transfer and flattened ends for connection. This segmentation allows each portion to be optimized for its specific function, enabling conventional welding at the ends while maintaining the corrugated structure's heat exchange capability in the middle section.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the heat exchange plate have different geometries tailored to their functions: the middle portion maintains corrugations for heat transfer, while the ends are flattened to provide a smooth, planar surface suitable for conventional welding and fluid-tight sealing, eliminating the need for vacuum brazing.

Inventive Principle:

Principle #3Local quality

2Reliability

If vacuum brazing is used to connect corrugated heat exchange plates, then fluid-tight connections are achieved, but manufacturing cost increases

Engineering Contradiction:

Improvefluid-tight connectionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The heat exchange plate is divided into two distinct zones: a corrugated middle portion for heat transfer and flattened ends for connection. This segmentation allows each portion to be optimized for its specific function, enabling conventional welding at the ends while maintaining the corrugated structure's heat exchange capability in the middle section.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the heat exchange plate have different geometries tailored to their functions: the middle portion maintains corrugations for heat transfer, while the ends are flattened to provide a smooth, planar surface suitable for conventional welding and fluid-tight sealing, eliminating the need for vacuum brazing.

Inventive Principle:

Principle #3Local quality

3Temperature

If corrugated heat exchange plates with low thickness are used, then heat transfer efficiency is maintained, but connection reliability deteriorates

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidconnection reliability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The heat exchange plate is divided into two distinct zones: a corrugated middle portion for heat transfer and flattened ends for connection. This segmentation allows each portion to be optimized for its specific function, enabling conventional welding at the ends while maintaining the corrugated structure's heat exchange capability in the middle section.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the heat exchange plate have different geometries tailored to their functions: the middle portion maintains corrugations for heat transfer, while the ends are flattened to provide a smooth, planar surface suitable for conventional welding and fluid-tight sealing, eliminating the need for vacuum brazing.

Inventive Principle:

Principle #3Local quality

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 approach allows for robust, fluid-tight welded joints and increased manufacturing efficiency by enabling the use of conventional welding methods, such as arc or torch welding, while maintaining the heat transfer efficiency of the corrugated design.

Implementation Method 1

a corrugated, cylindrical heat exchange plate having opposing first and second flattened ends separated by a middle portion containing unflattened corrugations containing gas flow channels

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS11990652B2Fuel cell system heat exchanger including welded heat exchange plate and method of forming same

Publication Date: 2024.05.21 BLOOM ENERGY CORP

AI summary

A method of forming a fuel cell system heat exchanger includes flattening opposing ends of a corrugated heat exchange plate to form opposing flattened ends, and welding the flattened ends to structural components of the fuel cell system. The flattening may include using a hydraulic press or a bead roller.