Systems and methods for managing conditions in enclosed space

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Solution Overview

Problem

Current cooling systems for enclosed spaces, such as data centers, face challenges including high energy consumption, dust accumulation, contaminant transfer, and limited climate suitability due to existing evaporative and air-side/water-side economizer methods, which require frequent maintenance and backup equipment.

Innovation Solution

A system combining a direct evaporative cooler (DEC) with an air-to-air heat exchanger (AAHX), including a sensible wheel, to indirectly and sensibly cool process air, reducing dust and contaminant transfer risks and allowing for better humidity control, while expanding the cooling range beyond wet-bulb temperature limitations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If air-side economizer is used to reject heat from data center, then energy consumption is reduced, but risk of dust accumulation and air contaminants increases

Engineering Contradiction:
Improveair-conditioning energy consumptionVSAvoiddust accumulation and air contaminants
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an air-to-air heat exchanger as an intermediary device between the outdoor air and the data center air. This heat exchanger transfers heat from the data center air to the outdoor air without direct mixing of the air streams, thereby rejecting heat while preventing dust and contaminants from entering the data center. The heat exchanger acts as a mediator that achieves thermal transfer without the harmful side effects of direct air-side economizer operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If direct evaporative cooler is used to cool buildings, then energy efficiency is improved, but indoor air quality deteriorates due to contaminant carryover

Engineering Contradiction:
Improvecooling energy consumptionVSAvoidindoor air quality and contaminants
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent segments the cooling process into two separate stages performed by different devices: first, the air-to-air heat exchanger performs sensible heat rejection, and second, the direct evaporative cooler performs latent cooling. This segmentation allows each device to operate in its optimal mode without the drawbacks of combining them in a single system. The DEC operates on outdoor air rather than indoor air, preventing contaminant carryover into the data center.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The air-to-air heat exchanger serves as an intermediary that handles the sensible heat rejection before the air reaches the direct evaporative cooler. This intermediary device protects the indoor environment by preventing direct contact between the evaporative cooler's water spray and the data center air stream, thereby eliminating the contaminant carryover problem while maintaining energy efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If evaporative cooler operates alone, then system complexity is reduced, but cooling temperature is limited by wet bulb temperature

Engineering Contradiction:
Improvesystem complexityVSAvoidcooling temperature capability
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent merges two cooling technologies - the air-to-air heat exchanger and the direct evaporative cooler - into a hybrid system. The heat exchanger handles sensible heat rejection down to outdoor air temperature, while the DEC provides additional cooling down to the wet bulb temperature. This combination allows the system to achieve lower temperatures than either device could accomplish alone, effectively expanding the cooling temperature capability without excessive complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a continuous cooling action chain where the air-to-air heat exchanger continuously rejects sensible heat, and the direct evaporative cooler continuously provides latent cooling. This continuous operation of both devices in sequence ensures that the full cooling potential is utilized, allowing the system to maintain temperatures below the wet bulb temperature limit by combining the effects of both cooling mechanisms.

Inventive Principle:
Principle #20Continuity of useful action

4Power

If water-side economizer (cooling tower) is used, then cooling capacity is improved, but maintenance challenges increase due to mineral deposition and biofilm growth

Engineering Contradiction:
Improvecooling capacityVSAvoidmaintenance requirements
Core Design Contradiction:
PowerVSEase of repair

Solution Approach 1:

The patent replaces the water-based cooling tower system with an air-based cooling system consisting of an air-to-air heat exchanger and a direct evaporative cooler. This substitution eliminates the water circulation system that causes mineral deposition, corrosion, and biofilm growth. The new system uses only air and evaporative water (which does not circulate), thereby eliminating the maintenance challenges associated with water-side economizers while maintaining or improving cooling capacity.

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

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 combination reduces air filtration needs, enhances humidity control, and eliminates the need for backup chillers, improving system efficiency, flexibility, and cost-effectiveness across various climates and applications.

Implementation Method 1

a direct evaporative cooler (DEC) in a scavenger air stream to cool the scavenger air stream below an outdoor air wet bulb temperature

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

an air-to-air heat exchanger exchanging heat between the scavenger air stream and a process air stream

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3158271B1Systems and methods for managing conditions in enclosed space
Publication Date: 2021.09.22 NORTEK AIR SOLUTIONS CANADA INC
  • EP3158271B1 patent drawingFigure 1
  • EP3158271B1 patent drawingFigure 2
  • EP3158271B1 patent drawingFigure 3~4

AI summary

Systems and methods for controlling temperature in an enclosed space can include an air-to-air heat exchanger (AAHX) and a direct evaporative cooler (DEC). The DEC can be located in a scavenger or outdoor air stream such that the DEC cools the outdoor air, which is then used to cool or reject heat from a process air stream passing through the AAHX. In an example, the AAHX can be a sensible wheel. In another example, the AAHX can be a counter-flow flat plate. The system can operate in various modes, including an economizer mode and an evaporation mode, depending, in part, on the outdoor air conditions and a load on the system. In some examples, the system can include a DX coil to provide additional cooling to the process air in another operating mode.