Heat Exchanger Return Header Design for Even Coolant Distribution

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Solution Overview

Problem

Existing heat exchangers experience uneven distribution of coolant in the vertical direction due to gravity, leading to areas that do not contribute to heat exchange, resulting in reduced efficiency.

Innovation Solution

A heat exchanger design with a return header formed by joining platy members with concave portions to connect inlet-side and outlet-side heat exchanger tubes, reducing the size of the return header while maintaining strength and ensuring even coolant distribution across multiple tubes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional heat exchanger designs are used, then structural simplicity is maintained, but heat transfer efficiency is insufficient

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidstructural complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The heat exchanger is divided into multiple heat transfer modules arranged in series, where each module contains alternating first and second heat transfer plates forming separate fluid passages. This segmentation increases the total heat transfer area and improves efficiency while maintaining a modular structure that doesn't overly complicate the overall design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a vertical stacking arrangement of heat transfer plates in multiple layers, transitioning from a single-plane to a three-dimensional configuration. This dimensional change significantly increases heat transfer area within a compact volume, improving efficiency without proportionally increasing structural complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If heat exchanger size is reduced, then installation space is saved, but heat transfer area is insufficient

Engineering Contradiction:
Improveheat exchanger volumeVSAvoidheat transfer area
Core Design Contradiction:
Volume of moving objectVSProductivity

Solution Approach 1:

Multiple heat transfer plates are nested vertically to form compact layers, with fluid passages arranged in alternating patterns between adjacent plates. This nesting approach packs maximum heat transfer area into minimal volume, achieving high productivity within a compact footprint suitable for space-constrained installations.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes vertical stacking of heat transfer plates to transition from a two-dimensional to three-dimensional heat transfer area distribution. This allows the heat exchanger to achieve large total heat transfer area while maintaining a small horizontal footprint, effectively resolving the volume-productivity contradiction.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Object-generated harmful factors

If fluid passages are enlarged, then flow resistance is reduced, but heat transfer area is reduced

Engineering Contradiction:
Improveflow resistanceVSAvoidheat transfer area
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The fluid passages are segmented into multiple parallel channels formed between alternating heat transfer plates. This segmentation distributes the total flow across multiple smaller passages, reducing flow resistance through increased surface area while maintaining adequate passage dimensions for smooth flow, thereby resolving the contradiction between flow resistance and heat transfer area.

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

The design inhibits areas that do not contribute to heat exchange, enhancing overall heat exchange efficiency by maintaining even coolant distribution and reducing the size of the return header for space savings.

Implementation Method 1

a first fluid passage extending through the heat exchanger from a first end to a second end, a second fluid passage extending through the heat exchanger from the first end to the second end

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4095475B1Heat exchanger
Publication Date: 2026.05.06 GENERAL INC
  • EP4095475B1 patent drawingFigure 1
  • EP4095475B1 patent drawingFigure 2
  • EP4095475B1 patent drawingFigure 3

AI summary

A heat exchanger includes an inlet header (120) in which a first inlet space and a second inlet space adjacent to and under the first inlet space are formed; a plurality of inlet-side heat exchanger tubes (111a) that includes a plurality of first inlet-side heat exchanger tubes that are connected to the first inlet space and a plurality of second inlet-side heat exchanger tubes that are connected to the second inlet space; a return header (170) in which a plurality of return spaces are formed, the return spaces including a plurality of first return spaces (5-1) that are connected to the first inlet-side heat exchanger tubes, respectively, and a plurality of second return spaces (5-2) that are connected to the second inlet-side heat exchanger tubes, respectively; and a plurality of outlet-side heat exchanger tubes (111b) that are connected to the return spaces, respectively, wherein a communication path (21) that enables a first return space (6) on a bottom side among the first return spaces (5-1) and a second return space (7) on a top side among the second return spaces (5-2) to communicate is further formed in the return header (170) .