Method of producing a micro-core heat exchanger for a compact indirect evaporative cooler

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Solution Overview

Problem

Manufacturing compact heat exchanger cores with small micro-cores faces challenges in connecting inlet and outlet manifolds to the narrow passages, and the conventional method of producing individual plates is time and labor-intensive.

Innovation Solution

A method involving a hydrophobic material roll with flocking and embossing to form air flow guiding structures, accordion pleating to create alternating wet and dry passages, and slits that open to form air inlets and outlets, allowing for efficient and precise alignment and sealing of the core.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the spacing between plates is greatly reduced to create micro-cores, then the heat exchanger becomes more compact and efficient, but it becomes increasingly problematic to connect inlet and outlet manifolds to the smaller passages in commercial scale manufacturing

Engineering Contradiction:
Improvecore sizeVSAvoidmanifold connection difficulty
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The continuous sheet is divided into multiple plates through embossed fold lines that guide folding. Each plate segment contains integrated manifold connection features, eliminating the need for separate manifold assembly and solving the connection difficulty in compact cores

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The manifold connections are integrated into the plate structure itself through embossed features on the sheet before folding. This transforms the connection problem from a three-dimensional assembly challenge into a two-dimensional pattern layout problem that can be solved in the flat sheet stage

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

2Reliability

If conventional manufacturing methods are used involving individual plate production, stacking, and bonding, then the heat exchanger can be manufactured, but the process becomes time and labour intensive

Engineering Contradiction:
Improvemanufacturing reliabilityVSAvoidproduction speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Multiple plates are formed from a single continuous sheet through embossing and folding, merging the production of multiple components into one continuous process. This eliminates separate manufacturing, handling, and bonding operations for each plate, dramatically increasing productivity while maintaining structural integrity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

All plate features including fold lines, sealing structures, and manifold connections are pre-formed in the flat sheet before folding. This preliminary formation of all necessary features eliminates time-consuming post-assembly operations and ensures consistent alignment

Inventive Principle:
Principle #10Preliminary action

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 method enables the economical and reliable manufacturing of compact heat exchanger cores with precise alignment and sealing, improving heat transfer efficiency and reducing production time, applicable to various heat exchanger types.

Implementation Method 1

providing a flock material on at least a partial surface area of at least one side of the hydrophobic material to render the flocked surface area wettable

Methodology Applied
Scientific EffectWetting: Wetting

Implementation Method 2

embossing the hydrophobic material to form air flow guiding structures therein

Methodology Applied
Scientific EffectFlow guidance:

Implementation Method 3

heat is transferred by convective transfer from the airstream to the cooled plate surfaces and by conductive heat transfer through the plates

Methodology Applied
Scientific EffectConductive heat transfer: Conduction (thermal)

Implementation Method 4

heat is transferred by convective transfer from the airstream to the cooled plate surfaces

Methodology Applied
Scientific EffectConvective heat transfer: Convection

Implementation Method 5

In the wet passages a 'working' airstream passes over wetted surfaces, accepting and carrying away sensible heat as well as latent heat of evaporation

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3262365B1Method of producing a micro-core heat exchanger for a compact indirect evaporative cooler
Publication Date: 2019.11.27 SEELEY INTERATIONAL
  • EP3262365B1 patent drawingFigure 1
  • EP3262365B1 patent drawingFigure 2
  • EP3262365B1 patent drawingFigure 3

AI summary

An indirect evaporative cooler core is manufactured from a continuous sheet of hydrophobic material. Flocking is provided on at least a partial surface area of at least one side of the sheet, to render the flocked surface area wettable. Air flow guiding structures are formed upon at least one of the first side and the second side of the sheet. Fold lines are defined in the sheet defining plates extending between adjacent fold lines. Slits are formed along the fold lines. Accordion pleating the sheet at the fold lines forms alternating wet and dry passages between the plates, the wet passages formed between opposing wettable surfaces, the dry passages formed between non- flocked surfaces, and the accordion pleating causes the slits in the folds to open and form air inlets and outlets in communication with the air flow passages.