Heat Exchanger Relay Layout to Prevent Refrigerant Stream Merging

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Solution Overview

Problem

In existing heat exchangers, the relay passages connect multiple second heat transfer pipes to multiple first heat transfer pipes, causing refrigerant streams to merge and then distribute, resulting in increased pressure loss when acting as an evaporator.

Innovation Solution

The heat exchanger design includes relay passages with a single inlet connected to each second heat transfer pipe and multiple outlets connected to corresponding first heat transfer pipes, distributing refrigerant without merging streams, thereby reducing pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If relay passages have multiple inlets connected to second heat transfer pipes and multiple outlets connected to first heat transfer pipes, then the heat exchanger can connect main and sub heat exchange units, but refrigerant streams merge and then distribute, resulting in increased pressure loss

Engineering Contradiction:
Improverelay passage configurationVSAvoidrefrigerant pressure loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The relay passages are segmented into multiple independent passages, where each relay passage has exactly one inlet connected to a corresponding second heat transfer pipe and multiple outlets connected to corresponding first heat transfer pipes. This segmentation prevents refrigerant streams from merging within the relay unit, as each inlet feeds a separate relay passage that directly distributes to multiple outlets without convergence with other streams.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If relay passages merge refrigerant streams, then multiple second heat transfer pipes can be connected to multiple first heat transfer pipes through a common relay unit, but pressure loss increases due to merging and redistribution

Engineering Contradiction:
Improverelay unit connectivityVSAvoidrefrigerant pressure loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The relay unit is segmented into multiple independent relay passages, each maintaining separate refrigerant flow paths from their respective inlets to their outlets. This allows the relay unit to connect multiple second heat transfer pipes to multiple first heat transfer pipes while preventing stream merging, as each passage operates independently with its own inlet-outlet configuration.

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If relay passages have one inlet and multiple outlets per passage, then refrigerant distributes without merging streams, but the relay unit structure becomes more complex

Engineering Contradiction:
Improverefrigerant pressure lossVSAvoidrelay passage configuration
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The relay unit is divided into multiple relay passages, with each passage being a separate flow path element. This segmentation into standardized one-inlet-multiple-outlets passages creates a modular structure that, while having more components, provides systematic and repeatable manufacturing patterns that can offset the apparent complexity through standardization.

Inventive Principle:
Principle #1Segmentation

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 refrigerant pressure loss through the relay unit, enhancing heat transfer performance and reducing the risk of refrigerant flow rate issues, while maintaining efficient heat exchange in both evaporator and condenser modes.

Implementation Method 1

Each of the plurality of relay passages distributes refrigerant flowing from the one inlet, without merging streams of the refrigerant together, and causes the refrigerant to flow out of the plurality of outlets

Methodology Applied
Scientific EffectPressure loss reduction through non-merging flow distribution:

Implementation Method 2

When the heat exchanger acts as an evaporator, refrigerant flows into the first heat transfer pipes from the second heat transfer pipes through the relay passages. When the heat exchanger acts as a condenser, the refrigerant flows into the second heat transfer pipes from the first heat transfer pipes through the relay passages

Methodology Applied
Scientific EffectHeat transfer:

Data Source

PatentEP3205968B1Heat exchanger and air conditioning device
Publication Date: 2019.02.20 MITSUBISHI ELECTRIC CORP
  • EP3205968B1 patent drawingFigure 1~3
  • EP3205968B1 patent drawingFigure 4~5
  • EP3205968B1 patent drawingFigure 6~8

AI summary

A heat exchanger (1) includes a main heat exchange unit (10) including a plurality of first heat transfer pipes (11) arranged side by side, a sub-heat exchange unit (20) including a plurality of second heat transfer pipes (21) arranged side by side, and a relay unit (40) including a plurality of relay passages (40A) connecting the plurality of first heat transfer pipes (11) and the plurality of second heat transfer pipes (21). Each of the plurality of relay passages (40A) has one inlet (40Aa) connected to a corresponding one of the plurality of second heat transfer pipes (21), and a plurality of outlets (40Ab) each connected to a corresponding one of the plurality of first heat transfer pipes (11). Each of the plurality of relay passages (40A) distributes refrigerant flowing from the one inlet (40Aa), without merging streams of the refrigerant together, and causes the refrigerant to flow out of the plurality of outlets (40Ab).