Multi-Phase Plate Heat Exchanger for Hygroscopic Air Conditioning

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Solution Overview

Problem

Current air conditioning systems consume high amounts of energy and fail to efficiently utilize heat recovery, especially in extreme climatic conditions, due to inefficiencies in heat exchangers that do not simultaneously facilitate cooling, condensation, and evaporation, leading to increased energy demands and humidity-related issues.

Innovation Solution

A multi-phase plate heat exchanger design that enables efficient evaporative cooling and heating through countercurrent or parallel flow of gaseous media with liquids on active heat transfer surfaces, allowing for precise liquid distribution, uniform wetting, and hygroscopic solution regeneration, while maintaining hygienic conditions and compactness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional heat exchangers are used for air conditioning, then cooling and heating can be achieved, but energy consumption is high and heat recovery is inefficient

Engineering Contradiction:
Improveenergy consumptionVSAvoidheat recovery efficiency
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent combines multiple functions (cooling, heating, condensation, evaporation, and heat recovery) into a single heat exchanger system. The heat exchanger simultaneously performs cooling of supply air and heating of exhaust air, condenses water vapor from supply air, and evaporates water into exhaust air, thereby recovering both sensible and latent heat. This integration eliminates the need for separate systems and significantly improves energy efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes phase transitions of water (condensation and evaporation) as core mechanisms for heat transfer. Water vapor in the supply air condenses on the cold surface, releasing latent heat that is transferred to the exhaust air. Simultaneously, water evaporates into the exhaust air, absorbing heat and cooling it. This phase change-based heat recovery efficiently handles both sensible and latent heat loads.

Inventive Principle:
Principle #36Phase transitions

2Productivity

If cooling and heating, condensation and evaporation take place simultaneously in the same place, then heat recovery efficiency improves, but the heat exchanger design becomes more complex

Engineering Contradiction:
Improveheat recovery efficiencyVSAvoidheat exchanger design
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The heat exchanger is divided into distinct functional zones or surfaces within a single integrated structure. Different surfaces are optimized for different functions: cold surfaces for condensation and cooling, warm surfaces for evaporation and heating. This segmentation allows simultaneous performance of multiple functions while maintaining a compact, manageable design that avoids excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heat exchanger is designed as a multi-functional device that performs cooling, heating, condensation, and evaporation simultaneously. By making the heat exchanger universal and capable of handling multiple thermodynamic processes in one unit, the design achieves high heat recovery efficiency without requiring multiple separate components, thus limiting the increase in complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If constant humidification of heat exchanger surfaces is applied, then evaporative cooling efficiency improves, but bacterial and microbial growth increases

Engineering Contradiction:
Improveevaporative cooling efficiencyVSAvoidmicrobial growth
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The heat exchanger surfaces are designed with different local properties: some surfaces are hydrophilic to promote water film formation and evaporation for cooling, while other surfaces or zones are designed to be hydrophobic or have antimicrobial properties to prevent microbial growth. This local differentiation allows the system to maintain evaporative cooling efficiency in necessary areas while preventing microbial contamination in vulnerable areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent converts the potential harm of water accumulation (which promotes microbial growth) into a benefit by designing the heat exchanger to rapidly evaporate water through controlled airflow and surface properties. The water that would otherwise stagnate and promote microbial growth is instead used for evaporative cooling, where it quickly evaporates, leaving no standing water for microbial proliferation. This transforms the potential harm into a useful cooling mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 multi-phase plate heat exchanger achieves significant energy savings by utilizing hygroscopic solutions for air conditioning, regulating humidity, and regenerating solutions effectively, allowing for efficient cooling and heating without excessive energy consumption and minimizing microbial growth.

Implementation Method 1

hygroscopic Liquid from warm humid air by sorption extracts water vapor with heat release

Methodology Applied
Scientific EffectSorption: Sorption

Implementation Method 2

Heat recovery can only take place efficiently if cooling and heating, condensation and evaporation take place simultaneously

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

heat exchanger between supply and exhaust air according to the preamble of claim 1 is known, where these two air flows are separated by a heat-conducting wall

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 4

the condensation water is discarded instead of being used for evaporative cooling

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3436757B1Air-conditioning via multi-phase plate heat exchanger
Publication Date: 2020.01.22 KUNZE GERHARD
  • EP3436757B1 patent drawingFigure 1a
  • EP3436757B1 patent drawingFigure 1b
  • EP3436757B1 patent drawingFigure 1c

AI summary

The invention relates to a multi-phase plate heat exchanger for 2 air media, wherein the surfaces (13a) are wetted for the heat transfer of fluids (3, 4), and the primary medium (1) is the warm and moist fresh air (15) and the secondary medium (2) is the cool dry exhaust air (16) of an occupied space, which flows in the opposite direction to the primary medium (1), wherein the surfaces of the plate gaps (1a) for the primary medium (1) are wetted with hygroscopic solution (17a) and the surfaces of the plate gaps (2a) for the secondary medium (2) are wetted with water (18), and wherein the regeneration of this hygroscopic solution (17b) occurs in a heat exchanger (14), in which the surfaces of the plate gaps (1a) for the primary medium (1) are wetted with preheated thinned hygroscopic solution (17b), and wherein the secondary medium (2) is air (15c) which is heated after the primary passage through the heat exchanger (14) and is saturated with steam, such that, on the surfaces of the plate gaps (1a) for the secondary medium (2), evaporation heat is fed back via the formation of condensation during the cooling thereof.