Horizontal Header Heat Exchanger for Uniform Refrigerant Flow

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Solution Overview

Problem

Heat exchangers with multi-hole flat tubes and vertical headers experience performance decline due to liquid refrigerant pooling, leading to uneven refrigerant flow and increased pressure loss, as the refrigerant flow channels at the bottom become submerged in liquid refrigerant during condensation.

Innovation Solution

Arranging headers horizontally to reduce the risk of refrigerant flow channels being immersed in liquid refrigerant, minimizing liquid retention, and optimizing flow channel cross-sections and configurations to enhance flow resistance and heat transfer efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the header is arranged to extend along the vertical direction, then the structure is compact and easy to install, but liquid refrigerant pools in the header interior causing refrigerant flow channels to be submerged and heat exchange performance to decline

Engineering Contradiction:
Improveheader arrangement structureVSAvoidheat exchange performance
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent inverts the conventional vertical header arrangement to a horizontal arrangement. This inversion changes the gravitational effect on liquid refrigerant, preventing it from submerging the refrigerant flow channels in the multi-hole flat tubes, thereby maintaining heat exchange performance while keeping the structure compact.

Inventive Principle:
Principle #13The other way round (Inversion)

2Temperature

If the multi-hole flat tubes are arranged to extend along the vertical direction, then the flow channel cross-section is optimized for heat transfer, but liquid refrigerant must be lifted against gravity causing increased pressure loss

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidpressure loss
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent inverts the arrangement direction of multi-hole flat tubes from vertical to horizontal extension. This inversion eliminates the need to lift liquid refrigerant against gravity, significantly reducing pressure loss while maintaining effective heat transfer through optimized flow channel cross-sections.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent optimizes the flow channel cross-sections locally within the multi-hole flat tubes to ensure efficient heat transfer. By adjusting the cross-sectional dimensions and shapes of individual flow channels, the patent maintains high heat transfer efficiency despite the horizontal arrangement that reduces gravitational effects.

Inventive Principle:
Principle #3Local quality

3Area of stationary object

If the refrigerant flow channels are positioned at the bottom of multi-hole flat tubes, then heat exchange area is maximized, but channels become submerged in liquid refrigerant causing uneven flow distribution

Engineering Contradiction:
Improveheat exchange areaVSAvoidflow distribution uniformity
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent inverts the spatial relationship between liquid refrigerant and refrigerant flow channels by changing from vertical to horizontal header arrangement. This prevents liquid refrigerant from submerging the bottom-positioned flow channels, ensuring uniform flow distribution while maintaining maximum heat exchange area.

Inventive Principle:
Principle #13The other way round (Inversion)

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 configuration reduces performance decline, minimizes pressure loss, and ensures uniform refrigerant distribution, maintaining heat exchange efficiency even when liquid refrigerant pools, by preventing submersion of refrigerant flow channels and optimizing flow channel designs.

Implementation Method 1

a refrigerant that undergoes a phase change during heat exchange... when the refrigerant changes from a gas to a liquid during condensation

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

when the header is arranged so as to extend along a vertical direction, the refrigerant flow channels formed in the multi-hole flat tubes which, of the plurality of multi-hole flat tubes connected to the header, are those positioned at the bottom, will be submerged in the liquid refrigerant

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2942594B1Heat exchanger
Publication Date: 2019.04.24 DAIKIN INDUSTRIES LTD
  • EP2942594B1 patent drawingFigure 1
  • EP2942594B1 patent drawingFigure 2
  • EP2942594B1 patent drawingFigure 3

AI summary

Provided is a heat exchanger (10) for carrying out heat exchange between a refrigerant that undergoes a phase change during heat exchange, and another heating medium, the heat exchanger being provided with refrigerant headers (50), a plurality of multi-hole flat tubes (40), and a plurality of flat tubes (20). The refrigerant flows through the interior of the refrigerant headers (50). The multi-hole flat tubes (40) extend in a direction intersecting a lengthwise direction of the refrigerant headers (50). Within the multi-hole flat tubes (40) are formed a plurality of refrigerant flow channels through the interior of which the refrigerant flows. The flat tubes (20) are stacked in alternating fashion with respect to the plurality of multi-hole flat tubes (40). The other heating medium flows through the interior of the flat tubes (20). Additionally, the refrigerant headers (50) are arranged in such a way as to extend along a horizontal direction.