Air Handler Unit with Direct Misting for Efficient Heat Transfer

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Solution Overview

Problem

Traditional HVAC systems experience slowed heat transfer processes due to indirect heat transfer from air to metal coils and then to cold water, leading to decreased performance and output.

Innovation Solution

An advanced air handling unit (AHU) system utilizing a high pressure cold water misting system that generates 1.9 X 10^9 to 1.9 X 10^12 mist droplets from 1 liter of water, with droplets ranging from 0.1 to 0.01 mm in diameter, which are mixed with air flows for direct heat transfer, incorporating a mist supply system with a high pressure pump, nozzle, and controllable valve, and a drainage system, along with a controller to adjust mist droplet sizes and spread volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If indirect heat transfer through metal coils is used, then structural simplicity is maintained, but heat transfer efficiency deteriorates

Engineering Contradiction:
Improvestructural simplicityVSAvoidheat transfer efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent removes the metal coil intermediary from the heat transfer path. Instead of using traditional evaporator coils, the system directly sprays chilled water onto the air stream, eliminating the metal barrier that impedes heat transfer efficiency while maintaining system functionality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces chilled water spray as a new intermediary medium between the cooling source and air. The water droplets act as mobile heat transfer carriers, directly contacting the air stream and enabling efficient heat exchange without requiring metal coil structures

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If chilled water is sprayed directly into air stream, then heat transfer efficiency is improved, but system complexity increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs hydraulic principles by using a water spray system with pumps, nozzles, and distribution pipes to deliver chilled water directly into the air stream. This hydraulic approach enables controlled water delivery and atomization, achieving efficient heat transfer through properly engineered fluid delivery mechanisms

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the physical state and distribution parameters of chilled water by atomizing it into fine droplets through spray nozzles. This parameter change from bulk liquid to dispersed droplets dramatically increases the surface area for heat transfer, improving efficiency while the spray system manages the complexity

Inventive Principle:
Principle #35Parameter changes

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 system achieves efficient and direct heat transfer between air flows and mist, improving heat transfer and system efficiency compared to traditional AHU systems.

Implementation Method 1

high pressure cold water mist is used in an air handling unit (AHU) of a heating, ventilation and air-conditioning (HVAC) system to achieve efficient cooling of air flows. The high pressure cold water mist is mixed with air flows in an air chamber and result in direct heat transfer between the mist and the air flows.

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

result in direct heat transfer between the mist and the air flows

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3775707B1Air handler unit
Publication Date: 2024.10.02 CARRIER CORP
  • EP3775707B1 patent drawingFigure 1
  • EP3775707B1 patent drawingFigure 2~3

AI summary

An air handling unit (AHU) system is provided and includes an AHU. The AHU includes an enclosure formed to define an inlet and at least one outlet downstream from the inlet, an air supply system to drive an air flow through the enclosure from the inlet to the outlet and a misting system operably coupled to the AHU. The misting system is configured to spray high pressure, cold water mist that includes mist droplets into a portion of the enclosure upstream from the at least one outlet whereupon heat transfer occurs directly between the mist droplets and air prior to the air reaching the outlet.