HVAC Baffle Layout for Refrigerant Leak Detection and Ignition Mitigation

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Solution Overview

Problem

HVAC systems using moderate-to-low GWP refrigerants face challenges in safely managing refrigerant leaks due to the potential for ignition from electrical components, as current solutions like redesigning components or complete sealing are costly and do not aid in leak detection.

Innovation Solution

A baffle is placed vertically adjacent to the heat exchanger with a fishbone or helical configuration to direct refrigerant leaks away from electrical components and towards a nondispersive infrared sensor for detection, mitigating ignition risks and facilitating leak detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If ignition components are redesigned or areas are completely sealed, then the risk of refrigerant ignition is reduced, but the cost of the unit significantly increases and leak detection capability is not improved

Engineering Contradiction:
Improveignition riskVSAvoidunit cost
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The baffle extracts and redirects the refrigerant leak flow away from the control box containing ignition components. By physically separating the refrigerant path from the electrical components, the system reduces ignition risk without requiring redesign of the ignition components or complete sealing of the control box, thus avoiding significant cost increases.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The baffle acts as an intermediary element between the refrigerant leak source and the control box. It intercepts the refrigerant flow and redirects it toward the drain pan, preventing direct contact between the refrigerant and potential ignition sources while maintaining system cost-effectiveness and enabling leak detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If ignition components are redesigned or areas are completely sealed, then the risk of refrigerant ignition is reduced, but leak detection capability is not improved

Engineering Contradiction:
Improveignition riskVSAvoidleak detection capability
Core Design Contradiction:
Object-affected harmful factorsVSDifficulty of detecting and measuring

Solution Approach 1:

The baffle serves as an intermediary that not only redirects refrigerant away from ignition sources but also channels the leak flow toward the drain pan area where leak detection sensors can be positioned. This dual function simultaneously reduces ignition risk and enhances leak detection capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of relying on complex sealed enclosures or redesigned components, the system uses a simple mechanical baffle structure to control refrigerant flow direction. This mechanical solution is cost-effective and can be easily integrated with sensor-based detection systems to monitor refrigerant leaks.

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

3Object-affected harmful factors

If a baffle is placed vertically adjacent to the heat exchanger, then refrigerant leaks are directed away from ignition sources and toward detection sensors, but device complexity increases

Engineering Contradiction:
Improveignition riskVSAvoidsystem structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The baffle divides the space around the heat exchanger into distinct zones: one where refrigerant leaks are redirected away from the control box, and another where leaks are channeled toward the drain pan and detection sensors. This spatial segmentation achieves safety and detection goals with a relatively simple structural addition.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The baffle introduces a vertical dimension to refrigerant flow control by being disposed vertically adjacent to the heat exchanger. This vertical orientation creates downward flow paths that naturally guide refrigerant away from horizontally positioned control boxes and toward the drain pan, adding a dimensional aspect to leak management without significantly increasing overall system complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 baffle effectively directs refrigerant leaks away from potential ignition sources and enhances detection capabilities, ensuring safer operation of HVAC systems with flammable refrigerants like A2L and A3 refrigerants by triggering appropriate responses when flammability limits are reached.

Implementation Method 1

The baffle is configured to direct at least a portion of a refrigerant leak away from the control box and toward a nondispersive infrared sensor

Methodology Applied
Scientific EffectFluid flow direction:

Implementation Method 2

at least a portion of the refrigerant leak is directed downward by the baffle toward a nondispersive infrared sensor

Methodology Applied
Scientific EffectInfrared detection: Infrared Radiation

Data Source

PatentEP3882528B1Baffle and method for directing refrigerant leaks
Publication Date: 2024.09.11 CARRIER CORP
  • EP3882528B1 patent drawingFigure 1
  • EP3882528B1 patent drawingFigure 2
  • EP3882528B1 patent drawingFigure 3

AI summary

A heating, ventilation, and/or air conditioning (HVAC) system (100) including a baffle (400) disposed vertically adjacent to a heat exchanger (210, 310), and a method (800) for controlling the flow of a refrigerant leak are provided. The baffle (400) may direct at least a portion of a refrigerant leak toward a refrigerant detection assembly (500). The refrigerant detection assembly (500) may include a nondispersive infrared (NDIR) sensor. The baffle (400) may include a fishbone configuration or a helical configuration. The baffle (400) may direct substantially all of the refrigerant leak away from a control box (340), which may include at least one potential ignition source (e.g., an electrical component (320), such as a contactor). When the heating, ventilation, and/or air conditioning (HVAC) system (100) utilizes a flammable refrigerant, the baffle (400) may help mitigate potential ignition of the flammable refrigerant.