Heat exchanger comprising microstructure elements and separation unit comprising such a heat exchanger

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Solution Overview

Problem

Conventional heat exchangers with small transverse dimensions in primary channels lead to uneven liquid distribution, resulting in dry areas that reduce performance and increase the risk of impurity deposits, compromising safety and efficiency in cryogenic gas separation units.

Innovation Solution

The heat exchanger features parallel plates with microstructure elements in primary channels, enhancing heat transfer and safety by increasing the wetted surface area without additional pressure drops, using microstructure elements with specific dimensions and distributions to ensure even liquid distribution and high wettability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional smooth primary channels with small transverse dimensions are used, then the heat exchanger structure is simple and easy to manufacture, but the primary liquid is not distributed evenly leading to dry areas that reduce heat transfer performance

Engineering Contradiction:
Improvechannel structure simplicityVSAvoidheat transfer performance
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies porous or rough surface materials on the primary channel walls to enhance capillary action. The microstructured surface creates capillary forces that actively draw the primary liquid across the entire channel perimeter, ensuring uniform distribution and eliminating dry areas while maintaining conventional channel geometry for ease of manufacture

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent modifies the surface parameters of the primary channel by introducing microstructures with specific dimensional parameters (porosity, surface area, roughness). These parameter changes enhance the wettability and capillary action without altering the overall channel geometry, thus improving heat transfer performance while keeping the structure manufacturable

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If smooth primary channels are used, then the manufacturing process is simple, but dry areas form that increase the risk of impurity deposits and compromise safety

Engineering Contradiction:
Improvechannel manufacturing simplicityVSAvoidsafety against impurity deposits
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The porous or rough surface materials create capillary forces that ensure continuous liquid coverage of the channel perimeter. This complete wetting prevents the formation of dry areas where impurities could accumulate, thereby eliminating the safety hazard while maintaining simple conventional channel geometry for ease of manufacture

Inventive Principle:
Principle #31Porous materials

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 improves heat transfer coefficients and safety by ensuring complete wetting of the primary channel perimeter, preventing dry vaporization and reducing the risk of impurity deposits, while maintaining conventional geometry for ease of manufacturing and operation.

Implementation Method 1

the microstructure elements are configured so that, for each rough primary channel: r>1+1.3⋅103⋅Ra⋅ε where r is the ratio of the actual area of a respective rough primary channel to the geometric area, Ra is the arithmetic mean deviation from the mean line representing roughness, and ε is the actual surface void ratio

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP3283835B1Heat exchanger comprising microstructure elements and separation unit comprising such a heat exchanger
Publication Date: 2019.06.05 LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE
  • EP3283835B1 patent drawingFigure 1~6
  • EP3283835B1 patent drawingFigure 4~5
  • EP3283835B1 patent drawingFigure 7

AI summary

The invention relates to a heat exchanger comprising parallel plates and spacers arranged in parallel and defining i) rough primary channels (21) and ii) secondary channels arranged so as to exchange heat. Said heat exchanger comprises a primary liquid inlet to be fluidically connected to a primary liquid dispenser. Each rough primary channel (21) has the shape of a prism having a polygonal cross-section and consisting of a plurality of essentially flat faces. The primary channels comprise rough primary channels. Each rough primary channel (21) has microstructure elements (30) which are distributed along the entire length of the channel and have dimensions of between 1 μm and 300 μm.