Heat Exchanger Coating for Thermoacoustic Impedance Matching

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Solution Overview

Problem

Existing heat exchanger technologies face challenges in enhancing heat transfer between solid surfaces and gases without increasing pressure drop, which hampers their efficiency, especially in gas flow applications.

Innovation Solution

A heat exchanger element with a coating of predetermined materials on its surface for thermo-acoustic impedance matching, utilizing non-metallic amorphous materials with intermediate impedance values to reduce thermal resistance and enhance heat transfer between solid surfaces and gases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If classical heat transfer enhancement techniques (surface extensions, turbulence promotion, surface roughness increase) are used, then heat transfer efficiency is improved, but pressure drop increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidpressure drop
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The invention changes the thermal conductivity parameter of the surface material by applying a coating layer with optimized thermal conductivity (0.1-10 W/(m·K)). This parameter change enables improved heat transfer to gas without relying on turbulence promotion or surface area extension that would increase pressure drop

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The coating layer acts as an intermediary between the solid heat exchanger surface and the gas. It mediates heat transfer by providing intermediate thermal conductivity that bridges the gap between high-conductivity solids and low-conductivity gases, improving heat transfer efficiency without increasing pressure drop

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If surface area is increased through fins or extensions, then heat transfer capability is enhanced, but device complexity and pressure drop increase

Engineering Contradiction:
Improveheat transfer capabilityVSAvoidsurface extension structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Instead of changing the geometric parameter (surface area) through fins or extensions, the invention changes the material parameter (thermal conductivity) by applying a coating layer. This achieves enhanced heat transfer capability without increasing device complexity or creating additional pressure drop

Inventive Principle:
Principle #35Parameter changes

3Productivity

If thermal conductivity of surface material is increased, then heat transfer to gas is improved, but thermo-acoustic impedance mismatch increases

Engineering Contradiction:
Improveheat transfer to gasVSAvoidthermo-acoustic impedance matching
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention optimizes the thermal conductivity parameter of the coating layer within a specific range (0.1-10 W/(m·K)) to simultaneously achieve improved heat transfer to gas and appropriate thermo-acoustic impedance matching. This parameter optimization resolves the contradiction by finding the optimal value that satisfies both requirements

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The coating layer serves as an intermediary that provides intermediate thermal conductivity values between solids and gases. This intermediary function enables both improved heat transfer to gas and reduced thermo-acoustic impedance mismatch by bridging the property gap between the two media

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The solution effectively reduces the overall temperature difference between the solid surface and gas, improving heat transfer efficiency without increasing pressure drop, by matching thermo-acoustic impedances and optimizing phonon propagation, thereby outperforming classical heat transfer methods.

Implementation Method 1

the layer being suitable to enhance the heat transfer between the solid surface and said fluid by thermo-acoustic impedance matching

Methodology Applied
Scientific EffectThermo-acoustic impedance matching: Thermoacoustics

Implementation Method 2

optimizing phonon propagation, thereby outperforming classical heat transfer methods

Methodology Applied
Scientific EffectPhonon propagation:

Data Source

PatentEP3385656B1Use of a coating layer on a heat exchanger surface
Publication Date: 2020.09.16 KARLSRUHER INST FUR TECH
  • EP3385656B1 patent drawingFigure 1a~1b
  • EP3385656B1 patent drawingFigure 2
  • EP3385656B1 patent drawingFigure 3

AI summary

The present invention provides a heat exchanger element (1) and a method for manufacturing a heat exchanger element (1) being in contact with a gas (3), wherein said heat exchanger element (1) comprises at least one solid surface (2). Said solid surface (2) is coated with at least one layer (4) of a predetermined material, said layer being suitable to enhance the heat transfer between the solid surface (2) and said gas (3) by thermoacoustic impedance matching.