Dehumidifying method and dehumidifying device

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Solution Overview

Problem

Existing dehumidifying devices with desiccant wheels face challenges in supplying air with low relative humidity for applications beyond refrigerated warehouses, as the cooling step by the air cooler increases relative humidity, making it difficult to achieve low humidity without reducing thermal efficiency.

Innovation Solution

A dehumidifying method and device that uses a desiccant wheel with a heat pump system, including a temperature increasing step to raise the supply air temperature using regeneration air or outside air, which reduces relative humidity without affecting the heat pump's coefficient of performance, and optionally pre-cools the supply air to enhance dehumidification efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the air cooler cools the supply air after the desiccant wheel, then the supply air temperature is reduced, but the relative humidity increases

Engineering Contradiction:
Improvesupply air temperatureVSAvoidrelative humidity
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The patent divides the air handling process into separate functional sections: the desiccant wheel section for dehumidification and the air cooler section for temperature reduction. By segmenting these functions, the system can cool the air without re-introducing moisture that would occur if cooling happened before dehumidification, thus resolving the contradiction between temperature reduction and humidity control

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The desiccant wheel performs dehumidification before the air cooler performs cooling. This preliminary action of removing moisture prior to cooling prevents the subsequent cooling step from increasing relative humidity, thereby resolving the technical contradiction

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If the desiccant wheel adsorbs water vapor from supply air, then the relative humidity is reduced, but the supply air temperature increases due to exothermic reaction

Engineering Contradiction:
Improverelative humidityVSAvoidsupply air temperature
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

The patent converts the harmful effect of the exothermic reaction (temperature increase) into a beneficial element by using the warmed air to improve the efficiency of the desiccant wheel. The temperature increase from adsorption is utilized to enhance the desiccant's performance rather than being merely discarded as a negative side effect

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

Solution Approach 2:

The system changes the temperature parameter of the supply air through controlled cooling after adsorption. By adjusting the cooling degree and timing, the system optimizes the balance between removing the heat generated during adsorption and maintaining low relative humidity, thus resolving the contradiction between humidity reduction and temperature control

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If a temperature increasing step is added to raise supply air temperature after cooling, then relative humidity is reduced, but device complexity increases

Engineering Contradiction:
Improverelative humidityVSAvoidsystem structure
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent merges the temperature increasing function with the existing heat pump system by using the regeneration air heater. Instead of adding a separate heating device, the system combines the heating function into the regenerative cycle, thereby reducing device complexity while still achieving the goal of lowering relative humidity through temperature increase

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

Enables the supply of air with low relative humidity to consumers in a simple and cost-effective manner without reducing the thermal efficiency of the dehumidifying device, effectively addressing the limitations of existing systems.

Implementation Method 1

a desiccant wheel which has an adsorption surface supporting an adsorption material or a hydrophilic adsorption surface on the disc-shaped wheel surface. Such a desiccant wheel is capable of adsorbing water vapor on the adsorption surface from supply air

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

In the adsorption step, adsorption heat is generated due to exothermic reaction and increases the temperature of supply air

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Implementation Method 3

a heat pump device including an air cooler for cooling the dehumidified supply air after the adsorption step

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

an air heater for pre-heating regeneration air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3343117B1Dehumidifying method and dehumidifying device
Publication Date: 2019.09.04 MAYEKAWA MFG CO LTD
  • EP3343117B1 patent drawingFigure 1
  • EP3343117B1 patent drawingFigure 2
  • EP3343117B1 patent drawingFigure 3

AI summary

A dehumidifying method includes: a dehumidifying step of causing an adsorption surface of a desiccant wheel to adsorb water vapor in the supply air; a cooling step of cooling the supply air dehumidified in the dehumidifying step with an air cooler constituting a part of a heat pump device; a first temperature increasing step of increasing a temperature of the supply air cooled in the cooling step with a temperature increasing medium to reduce a relative humidity of the supply air; a supplying step of supplying an air conditioning chamber with the supply air having a reduced relative humidity; a second temperature increasing step of increasing a temperature of the regeneration air with an air heater constituting a part of the heat pump device to reduce a relative humidity of the regeneration air; and a desorbing step of desorbing the water vapor adsorbed on the adsorption surface from the adsorption surface with the heated regeneration air.