Corrugated Heat Exchanger Fin Thickness Layout for Brazing Erosion

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Solution Overview

Problem

The existing methods for manufacturing fins in heat exchangers face erosion issues when bonding thin metal plates with brazing materials, which can lead to increased flow path resistance and reduced heat exchange efficiency, as well as higher material costs and weight if the fin thickness is increased to prevent erosion.

Innovation Solution

A method of manufacturing corrugated fins with varying thickness, where the apex and valley portions are thicker than the inclined portions, preventing complete erosion during brazing while maintaining a thinner profile to minimize weight and material costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the thickness of the fin is increased to prevent erosion during brazing, then erosion resistance is improved, but flow path resistance increases and heat exchange efficiency is reduced

Engineering Contradiction:
Improveerosion resistanceVSAvoidheat exchange efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The fin is designed with non-uniform thickness distribution, where the apex portions have greater thickness than the inclined portions. This local quality variation ensures that the critical apex areas resistant to brazing material erosion while maintaining thinner sections elsewhere to preserve fluid flow characteristics and heat exchange efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fin structure is segmented into distinct regions with different thickness characteristics - thicker apex portions for erosion resistance and thinner inclined portions for optimal fluid flow. This segmentation allows each region to fulfill its specific functional requirement independently.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the thickness of the fin is increased to prevent erosion during brazing, then erosion resistance is improved, but material cost and weight increase

Engineering Contradiction:
Improveerosion resistanceVSAvoidfin weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

Instead of uniformly increasing fin thickness throughout, the invention applies increased thickness only to the apex portions where erosion occurs during brazing. This localized approach provides the necessary erosion resistance while minimizing additional material usage, weight, and cost.

Inventive Principle:
Principle #3Local quality

3Reliability

If the thickness of the fin is increased to prevent erosion during brazing, then erosion resistance is improved, but flow path resistance increases

Engineering Contradiction:
Improveerosion resistanceVSAvoidflow path resistance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The fin thickness is locally increased only at the apex portions where erosion resistance is needed, while the inclined portions and flow path areas maintain thinner profiles. This selective thickness distribution prevents erosion without significantly increasing flow path resistance.

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 effectively suppresses erosion during brazing, maintains heat exchange efficiency, and reduces the material and weight costs of the heat exchanger by ensuring the base material remains intact, even if erosion occurs.

Implementation Method 1

a part of the metal plate may be eroded by molten brazing material. Such a phenomenon is also called 'erosion'.

Methodology Applied
Scientific EffectErosion: Erosion

Implementation Method 2

compressing at least a portion to be the inclined portion of the metal plate by a pair of rollers, such that the thickness of the metal plate in the portion is made smaller than the thickness of the peak portions or the like

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3572757B1Method for manufacturing a heat exchanger fin
Publication Date: 2021.03.03 DENSO CORP
  • EP3572757B1 patent drawingFigure 1
  • EP3572757B1 patent drawingFigure 2
  • EP3572757B1 patent drawingFigure 3

AI summary

A fin according to the present disclosure is a corrugated fin (100) formed of a metal plate by bending into a corrugated shape, and the corrugated fin includes peak portions (110) extending in a first direction, valley portions (120) extending in the first direction, and inclined portions (130) connecting the peak portions and the valley portions adjacent to each other. The peak portions and the valley portions are alternately arranged in a second direction perpendicular to the first direction, and a thickness of the metal plate at each apex of the peak portions and the valley portions is larger than a thickness of the inclined portions of the metal plate.