Heat exchanger, and refrigerating cycle device equipped with heat exchanger

Solution Overview

Problem

The existing heat exchanger designs, such as those described in Patent Literature 1, suffer from uneven refrigerant distribution across heat exchange units, leading to reduced heat exchange efficiency due to the temporary merging of refrigerant streams in row straddling headers, which disrupts the initial even division of refrigerant flows.

Innovation Solution

A heat exchanger configuration with multiple heat exchange units arranged in rows, featuring a row straddling header with internal chambers that isolate refrigerant passages for each level, ensuring even distribution and maintaining the initial refrigerant state from inlets to outlets, utilizing a combination of flat tubes and fins with air passing between them, and employing headers to manage refrigerant flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the refrigerant streams are allowed to merge in the row straddling header, then the structure is simple, but the refrigerant distribution becomes uneven

Engineering Contradiction:

Improveheader structureVSAvoidrefrigerant distribution uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The row straddling header is divided into multiple independent chambers that are arranged in the level direction. Each chamber corresponds to a specific level and maintains isolated refrigerant passages, preventing mixing between different levels. This segmentation allows the header to remain structurally simple while ensuring uniform refrigerant distribution to heat exchange units at different levels.

Inventive Principle:

Principle #1Segmentation

2Productivity

If multiple heat exchange units are arranged in rows, then the heat exchange efficiency is improved, but the refrigerant flow distribution becomes uneven

Engineering Contradiction:

Improveheat exchange efficiencyVSAvoidrefrigerant flow distribution

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The row straddling header is divided into multiple independent chambers that are arranged in the level direction. Each chamber corresponds to a specific level and maintains isolated refrigerant passages, preventing mixing between different levels. This segmentation allows the header to remain structurally simple while ensuring uniform refrigerant distribution to heat exchange units at different levels.

Inventive Principle:

Principle #1Segmentation

3Manufacturing precision

If the refrigerant passages are isolated for each chamber, then the refrigerant distribution remains even, but the header structure becomes complex

Engineering Contradiction:

Improverefrigerant distribution uniformityVSAvoidheader internal structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The row straddling header is divided into multiple independent chambers that are arranged in the level direction. Each chamber corresponds to a specific level and maintains isolated refrigerant passages, preventing mixing between different levels. This segmentation allows the header to remain structurally simple while ensuring uniform refrigerant distribution to heat exchange units at different levels.

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 maintains an even refrigerant distribution throughout the heat exchanger, enhancing heat exchange performance by preventing mixing of streams and ensuring consistent flow, thereby improving the efficiency of the refrigeration cycle apparatus.

Implementation Method 1

a plurality of heat exchange units 10, 20 each including a plurality of heat transfer tubes 12, 22 through which a refrigerant in a gas-liquid two-phase state flows and a plurality of fins 11, 21 arranged such that air passes between adjacent fins in an air passing direction

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 2

a plurality of heat transfer tubes 12, 22 through which a refrigerant in a gas-liquid two-phase state flows and a plurality of fins 11, 21 arranged such that air passes between adjacent fins

Methodology Applied

Scientific EffectConduction (thermal): Conduction (thermal)

Data Source

PatentEP2865982B1Heat exchanger, and refrigerating cycle device equipped with heat exchanger

Publication Date: 2022.08.31 MITSUBISHI ELECTRIC CORP

Figure 1~2
Figure 3~4
Figure 5(a)~5(b)

AI summary

A heat exchanger includes a plurality of heat exchange units 10, 20 each including a plurality of fins 11, 21 arranged at intervals such that air passes between adjacent fins and a plurality of heat transfer tubes 12, 22 through which a refrigerant flows. The heat transfer tubes extend through the fins 11, 21 in a direction of arrangement of the fins. The heat transfer tubes are arranged at multiple levels in a level direction perpendicular to an air passing direction. The heat exchange units are arranged in multiple rows in a row direction, serving as the air passing direction. The heat exchanger further includes a row straddling header 40. Refrigerant passages are provided such that the refrigerant flowing from inlets of the refrigerant passages turns in the row straddling header 40 to outlets of the refrigerant passages. The row straddling header 40 has an interior separated into a plurality of chambers arranged in the level direction. The refrigerant passage is isolated for its corresponding chamber.