3D-Printed Microtube Heat Exchangers With Integrated Headers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Traditional compact heat exchangers, such as shell-and-tube exchangers, are poorly suited for transport vehicles due to their large size and weight, and existing manufacturing methods limit the achievement of high transfer surface area densities and heat transfer effectiveness.

Innovation Solution

Additive manufacturing techniques are used to create microtube heat exchangers with integrated headers and microtube arrays, allowing for complex geometries and high-density structures that achieve up to 20,000 m²/m³ surface area density and 90% heat transfer effectiveness by forming continuous solid bodies with microtubes and headers, and incorporating lattice structures for support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional manufacturing methods are used for heat exchangers, then structural strength is maintained, but surface area density and heat transfer effectiveness are limited

Engineering Contradiction:
Improvesurface area densityVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent merges the header and microtube array into a single integrated component manufactured through additive manufacturing. This integration eliminates the need for separate manufacturing and assembly processes, enabling complex geometries with high surface area density (up to 20,000 m²/m³) that would be impossible to achieve with traditional manufacturing methods while maintaining structural integrity through the continuous material deposition process

Inventive Principle:
Principle #5Merging (Combining)

2Manufacturing precision

If additive manufacturing is used to create integrated headers and microtube arrays, then surface area density increases to 20,000 m²/m³, but manufacturing process complexity increases

Engineering Contradiction:
Improvesurface area densityVSAvoidgeometric complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent utilizes parameter changes in the additive manufacturing process, specifically varying the tube diameter (down to micrometer scale) and spacing parameters to achieve the target surface area density of 20,000 m²/m³. The digital model allows precise control of geometric parameters including tube diameter, wall thickness, and spacing, enabling optimization of heat transfer surface area while managing manufacturing complexity through software-based process control

Inventive Principle:
Principle #35Parameter changes

3Reliability

If microtube arrays with diameter ≤2mm are manufactured, then heat transfer effectiveness reaches 90%, but manufacturing precision requirements increase

Engineering Contradiction:
Improveheat transfer effectivenessVSAvoidtube diameter precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces traditional mechanical manufacturing methods (such as drilling, boring, or extrusion) with additive manufacturing technology. This substitution enables precise control of tube diameter (≤2mm) and wall thickness through digital modeling and layer-by-layer material deposition, achieving the required manufacturing precision for high heat transfer effectiveness (90%) while eliminating the tolerances and tooling constraints of mechanical processes

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If traditional brazing techniques are avoided, then manufacturing time and complexity are reduced, but joining reliability must be maintained through alternative methods

Engineering Contradiction:
Improvemanufacturing timeVSAvoidjoint integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent merges the header and microtube array into a single monolithic component manufactured through additive manufacturing. This integration eliminates the need for separate joining operations such as brazing, welding, or mechanical fastening. The continuous material deposition process creates inherent joint integrity through the fused material structure, reducing manufacturing time and complexity while maintaining or improving reliability compared to traditional multi-step joining processes

Inventive Principle:
Principle #5Merging (Combining)

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 additive manufacturing of microtube heat exchangers results in compact, high-performance heat transfer systems with improved surface area density and effectiveness, reducing mass and enabling efficient heat exchange between fluids without the need for traditional brazing techniques.

Implementation Method 1

additive manufacturing techniques are used to create microtube heat exchangers with integrated headers and microtube arrays

Methodology Applied
Scientific EffectAdditive manufacturing: 3D Printing

Implementation Method 2

The at least one header is for directing a fluid through a plurality of tubes of the microtube array to transfer heat between the fluid and a medium external to the plurality of tubes

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3649419B1Apparatus and methods for additively manufacturing microtube heat exchangers
Publication Date: 2025.03.26 DIVERGENT TECHNOLOGIES INC
  • EP3649419B1 patent drawingFigure 1
  • EP3649419B1 patent drawingFigure 2
  • EP3649419B1 patent drawingFigure 3

AI summary

Apparatus and methods for additively manufacturing microtube heat exchangers are disclosed herein. A heat exchanger header is additively manufactured with high density microtube arrays to achieve an integrated structure achieving values of heat transfer effectiveness Eff up to ninety percent and values of transfer surface area densities up to 20,000 m2/m3. The heat exchanger header can be printed with a high density microtube array to separate different types of fluids or liquids into different microtubes and to form a high quality seal. Additionally, microtubes and/or microtube arrays can be additively manufactured to be curved or to have pleats; and microtube lattice arrays can be compactly positioned within hollow support structures.