Double Dimple Heat Exchanger Plates with Wall Sections

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Solution Overview

Problem

Conventional heat exchangers face challenges in achieving efficient heat transfer while maintaining stability and durability, particularly with dimple patterns that lead to uneven fluid flow and potential deformations under pressure, limiting the design of heat exchanger dimensions and gasket usage.

Innovation Solution

The use of wall sections connecting dimples with the same height as the dimples themselves, forming closed pairs that block fluid flow and creating patterns of rows to direct fluid flow effectively, while being elastically deformable to prevent permanent deformations, allows for improved heat transfer efficiency and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the contact surface area of neighboring heat exchanger plates is reduced to improve heat exchange efficiency, then the heat transfer efficiency is improved, but the durability and stability of the plates deteriorate due to insufficient resistance against high fluid pressures and external pre-tension

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoiddurability of heat exchanger plates
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The contact surface between neighboring plates is segmented into multiple discrete contact points formed by dimples rather than a continuous contact area. This segmentation allows the plates to maintain structural integrity while providing sufficient heat transfer pathways, as the dimples create localized contact zones that distribute mechanical stresses across multiple points rather than concentrating them on a single large area.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dimple pattern creates localized contact zones with specific geometric properties (depth, diameter, spacing) that optimize both mechanical support and heat transfer. The local geometry of each dimple is designed to provide adequate contact pressure for heat exchange while the overall distribution of dimples ensures sufficient structural support across the plate surface to resist high fluid pressures and external pre-tension.

Inventive Principle:
Principle #3Local quality

2Productivity

If the thickness of heat exchanger plates is reduced to improve heat exchange efficiency, then the heat transfer efficiency is improved, but the stability and resistance to deformation under pressure deteriorate

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidresistance to deformation
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The dimples introduce curved, spherical-like features on the plate surfaces that create favorable stress distribution patterns. The curved geometry of the dimples helps to distribute mechanical loads more evenly across the plate thickness, reducing stress concentrations that would otherwise lead to deformation. This allows thinner plates to maintain adequate structural strength while improving heat transfer efficiency through reduced thermal mass and increased surface area-to-volume ratio.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If conventional dimple patterns are used to create fluid flow paths, then heat exchange occurs, but the fluid flow becomes uneven leading to reduced heat transfer effectiveness

Engineering Contradiction:
Improveheat exchange occurrenceVSAvoidheat transfer effectiveness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The dimple pattern employs asymmetric arrangements where dimples are positioned and sized to create controlled variations in fluid flow paths. This asymmetric pattern prevents uniform, laminar flow that would reduce heat transfer effectiveness by creating dead zones and uneven velocity distributions. The asymmetric dimple placement forces the fluid to follow more turbulent, mixed flow paths that enhance heat exchange effectiveness while maintaining stable pressure distributions.

Inventive Principle:
Principle #4Asymmetry

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 solution enhances the stability and efficiency of heat exchangers by effectively directing fluid flow and preventing deformations, enabling the design of more robust and efficient heat exchangers with desired pressure and flow characteristics across various dimensions.

Implementation Method 1

at least some of the wall sections have the same height as the dimples forming closed dimple pairs and the wall sections of neighboring plates are in contact with each other completely blocking the fluid path where the closed dimple pairs and meet

Methodology Applied
Scientific EffectFluid flow blocking:

Implementation Method 2

Plate heat exchangers are well known devices for the transport for heat between two different media, in particular fluids

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

The two media will then be allowed to circulate between alternating pairs of plates to allow a transfer of heat through the heat exchanger plates

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

The wall sections connecting dimples with the same height as the dimples themselves, forming closed pairs that block fluid flow and creating patterns of rows to direct fluid flow effectively, while being elastically deformable to prevent permanent deformations

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2775247B1Double dimple pattern heat exchanger
Publication Date: 2018.11.28 DANFOSS AS
  • EP2775247B1 patent drawingFigure 1~2B
  • EP2775247B1 patent drawingFigure 3
  • EP2775247B1 patent drawingFigure 4~5

AI summary

The invention relates to a heat exchanger (1) comprising a plurality of heat exchanger plates (2), wherein each of the heat exchanger plates (2) comprises a plurality of dimples (8). The dimples (8) comprise tops (7) and bottoms (9). Furthermore, the tops of at least one heat exchanger plate (2) are connected to the bottoms of a neighboring heat exchanger plate (2). In order to improve the efficiency and stability of the heat exchanger at least part of the dimples (8) are connected to at least one adjacent dimple (8) by a wall section (10).