Air temperature and humidity control device

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Solution Overview

Problem

Conventional air conditioning systems are inefficient in humidity control, requiring significant energy for supercooling and reheating, and suffer from corrosion and maintenance issues due to direct contact methods, while desiccant wheel systems are space-consuming and cumbersome, and liquid desiccant systems generate noise and have modularity problems.

Innovation Solution

An air temperature and humidity control device using a heat pump with a liquid-liquid contactor featuring porous sidewalls for efficient water vapor transfer between liquid desiccant and vacuum or airflow, eliminating the need for direct contact and reducing energy consumption by leveraging pressure differences and heat exchange.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If direct expansion (DX) coils are used to condense moisture through supercooling, then humidity control is achieved, but significant energy is consumed and corrosion problems occur

Engineering Contradiction:
Improvehumidity control capabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent introduces a liquid desiccant as an intermediary substance between the air stream and the heat pump system. The liquid desiccant absorbs moisture from the air through direct contact in a contactor, eliminating the need for DX coils and supercooling. This mediator approach resolves the contradiction by providing humidity control through a less energy-intensive mechanism while avoiding corrosion issues associated with metallic DX coils.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the operating parameters from refrigerant-based phase change (supercooling) to liquid desiccant-based absorption. By altering the fundamental mechanism from thermal condensation to hygroscopic absorption, the system achieves humidity control with reduced energy consumption and without the corrosion problems inherent in DX coil systems.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If desiccant wheels are used for humidity control, then low humidity outputs are achieved, but the systems are space-consuming and require heating energy for regeneration

Engineering Contradiction:
Improvehumidity control capabilityVSAvoidsystem space
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent replaces the mechanical rotating desiccant wheel system with a liquid desiccant contactor system. Instead of using a solid desiccant on a rotating wheel that requires significant space and mechanical drive, the invention uses liquid desiccant flowing through a contactor where mass transfer occurs across a liquid-gas interface. This substitution eliminates the bulky mechanical structure while maintaining humidity control effectiveness.

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

3Use of energy by moving object

If liquid desiccant systems with direct contact are used, then energy consumption is reduced, but significant noises are generated and liquid desiccant entrainment causes corrosion and health issues

Engineering Contradiction:
Improveenergy consumptionVSAvoidnoise and liquid entrainment
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a membrane or packing material as an intermediary structure within the contactor. This intermediary provides a large surface area for mass transfer between the liquid desiccant and air stream while preventing direct bulk mixing. The result is reduced liquid entrainment into the air stream, eliminating corrosion and health issues, while maintaining the low energy consumption benefits of liquid desiccant technology.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If contact towers with packing materials are used, then humidity control is achieved, but the construction is cumbersome and not easy to modulate

Engineering Contradiction:
Improvehumidity control capabilityVSAvoidconstruction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the contactor into modular sections with standardized components such as removable packing materials and segmented liquid distribution systems. This segmentation allows the contactor to be constructed from standardized modules that can be easily assembled, disassembled, and configured for different applications, reducing construction complexity while maintaining effective humidity control.

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 solution enhances efficiency by minimizing energy use and reducing maintenance through efficient humidity control without direct contact, eliminating noise, and providing modular operation for a wide range of applications.

Implementation Method 1

The porous sidewall defines an internal space through which a liquid desiccant flows. A vacuum pump is coupled to the first contactor. The vacuum pump is configured to generate a pressure difference between an internal side and an external side of the porous sidewall such that water vapor transfers between the vacuum and the liquid desiccant.

Methodology Applied
Scientific EffectVapor transfer through porous material: Permeation

Implementation Method 2

The vacuum pump is configured to generate a pressure difference between an internal side and an external side of the porous sidewall such that water vapor transfers between the vacuum and the liquid desiccant.

Methodology Applied
Scientific EffectPressure difference driven mass transfer: Pressure Gradient

Implementation Method 3

The evaporator is configured to heat the liquid desiccant in the first contactor.

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2767771B1Air temperature and humidity control device
Publication Date: 2019.05.15 CARRIER CORP
  • EP2767771B1 patent drawingFigure 1
  • EP2767771B1 patent drawingFigure 2
  • EP2767771B1 patent drawingFigure 3

AI summary

An air temperature and humidity control device is provided including a heat pump and a humidity controller. The heat pump has a condenser, a first evaporator, a compressor, and a second evaporator. The humidity controller includes a first contactor fluidly coupled to the second evaporator. The first contactor includes at least one contact module having a porous sidewall that defines an internal space through which a liquid desiccant flows. A liquid source is coupled to the first contactor such that a second liquid provided by the liquid source flows through the first contactor adjacent an external side of the porous sidewall. Heat and/or water vapor transfers between the second liquid and the liquid desiccant.