Flat Tube Protrusions Block Fluid Bypass in Heat Exchangers

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Solution Overview

Problem

In heat exchangers with flat tubes, the space between the inner fin and the shorter sides of the tube can lead to reduced heat exchange performance due to fluid bypassing the fin.

Innovation Solution

The flat tube design incorporates protrusions on the side walls that at least partially block the flow of fluid near the side walls, guiding it towards the inner fin to enhance heat exchange.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an inner fin is provided inside the flat tube to increase heat exchange, then heat exchange performance is improved, but fluid may bypass through the space between the inner fin and the shorter sides, reducing effectiveness

Engineering Contradiction:
Improveheat exchange performanceVSAvoidfluid bypass loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The invention extracts the problematic space between the inner fin and shorter sides by introducing protrusions that extend into this space, effectively removing the bypass pathway while preserving the heat exchange function of the inner fin

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The protrusions act as intermediary elements between the inner fin and the shorter sides, blocking the bypass space without directly connecting to both components, thus preventing fluid leakage while maintaining heat exchange efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the inner fin does not contact the shorter sides due to welding joint or forming width limitations, then manufacturing is simplified, but heat exchange performance is reduced due to fluid bypass

Engineering Contradiction:
Improveinner fin installationVSAvoidheat exchange performance
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The protrusions serve as intermediary blocking elements that prevent fluid bypass in the gap between the inner fin and shorter sides, allowing the inner fin to be installed without direct contact with the shorter sides while maintaining heat exchange performance

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protrusions are strategically positioned at specific locations where fluid bypass occurs, providing localized blocking function without requiring the inner fin to contact the shorter sides, thus maintaining both manufacturing ease and heat exchange performance

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 design effectively reduces fluid bypass and enhances heat exchange efficiency by ensuring that the fluid interacts more closely with the inner fin.

Implementation Method 1

at least one protrusion protruding from the at least one of the two side walls, is configured to at least partially block the flow of fluid in the vicinity of the at least one of the two side walls

Methodology Applied
Scientific EffectFluid flow guidance:

Implementation Method 2

The first fluid flowing inside the flat tube exchanges heat with a second fluid flowing outside the flat tube

Methodology Applied
Scientific EffectHeat exchange: Conduction (thermal)

Data Source

PatentEP4553439A1A tube for a heat exchanger
Publication Date: 2025.05.14 VALEO SYST THERMIQUES SAS
  • EP4553439A1 patent drawingFigure 1
  • EP4553439A1 patent drawingFigure 2
  • EP4553439A1 patent drawingFigure 3

AI summary

A flat tube for a heat exchanger comprises a plurality of walls forming a fluid passage through which a fluid flows, at least one inner fin provided in the fluid passage and at least one protrusion protruding towards the inner fin, is provided in the fluid passage. The flat tube comprises a flat first wall, a flat second wall parallel to the first wall and two side walls joining the first wall and the second wall. The at least one inner fin is meandering between the first wall and the second wall of the flat tube. The at least one protrusion is protruding from the at least one of the two side walls and is configured to at least partially block the flow of fluid in the vicinity of the at least one of the two side walls.