Refrigeration system and associated method

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Solution Overview

Problem

Conventional refrigeration systems struggle to effectively cool high-temperature heat sources in electronics when cooling air is unavailable or insufficient, particularly in loss-of-cooling scenarios, necessitating improved systems for efficient heat management.

Innovation Solution

A refrigeration system utilizing an expander in the cooling branch to expand partially cooled refrigerant flow, combined with wafer heat exchangers and passive pumps, which leverage waste heat to provide cooling without compressors, employing a refrigerant loop with expanders and ejector pumps to manage thermal communication with electronics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional refrigeration systems are used for cooling aircraft electronics, then cooling can be provided when ambient conditions are favorable, but the system becomes inadequate when cooling air is unavailable or too hot

Engineering Contradiction:
Improvecooling reliabilityVSAvoidadaptability to loss-of-cooling scenarios
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system uses waste heat from aircraft engines to drive the refrigeration cycle, making the system self-sufficient and independent of ambient cooling air. The waste heat source provides the energy input needed to operate the refrigeration system, allowing it to function reliably in loss-of-cooling scenarios where conventional ambient air cooling fails.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes the thermodynamic parameters by using waste heat at higher temperatures to drive the refrigeration cycle, enabling cooling operation when ambient temperatures are too high for conventional systems. This parameter change allows the system to adapt to conditions where traditional ambient air cooling is ineffective.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If a compressor is used in conventional refrigeration systems, then refrigerant circulation is achieved, but the system complexity and energy consumption increase

Engineering Contradiction:
Improverefrigeration efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the compressor from the refrigeration system, replacing it with a simpler valve mechanism. This extraction of the complex compressor component reduces system complexity while maintaining refrigeration functionality through the alternative expansion valve design that uses waste heat-driven refrigerant circulation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical compressor system is replaced with a thermal-driven system using waste heat to circulate refrigerant. The expansion valve substitutes for the mechanical compressor, using thermodynamic principles rather than mechanical compression to achieve refrigeration, thereby reducing system complexity.

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

3Ease of operation

If cooling modules are provided for each heat source, then local cooling is achieved, but the system requires abundant cooling air which may not be available

Engineering Contradiction:
Improvelocal cooling capabilityVSAvoidcooling air consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

Each cooling module is designed to be self-contained, using the waste heat from aircraft engines to drive its own refrigeration cycle. The modules operate independently without requiring external cooling air, making them self-sufficient and suitable for loss-of-cooling scenarios where ambient air is unavailable or too hot.

Inventive Principle:
Principle #25Self-service

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 efficiently cools high-temperature electronics using waste heat, achieving temperatures below ambient limits without compressors, providing localized cooling with higher efficiency and flexibility, suitable for aircraft avionics.

Implementation Method 1

a heat input disposed in the main flow circuit and configured to receive heat and transfer the heat to the refrigerant in the main flow circuit

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

a passive pump disposed in the main flow circuit downstream of the heat input configured to receive the heated refrigerant flow from the heat input and to use the heated refrigerant flow to generate a vacuum at a pump port

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

The condenser can be configured to receive heat from the heated refrigerant flow and reject heat to cool the heated refrigerant flow

Methodology Applied
Scientific EffectHeat rejection: Heat Exchanger

Implementation Method 4

The expander can be configured to receive the partially cooled refrigerant flow and cause expansion cooling to output cooling flow to the one or more cooling modules

Methodology Applied
Scientific EffectExpansion cooling: Joule-Thomson Effect

Implementation Method 5

Each wafer heat exchanger can include an adhesive surface configured to stick to the heat source

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3789693B1Refrigeration system and associated method
Publication Date: 2026.04.15 HAMILTON SUNDSTRAND CORP
  • EP3789693B1 patent drawingFigure 1
  • EP3789693B1 patent drawingFigure 2
  • EP3789693B1 patent drawingFigure 3

AI summary

A refrigeration system (100) can include a main flow circuit (101) configured to flow a refrigerant therethrough and a heat input (103) disposed in the main flow circuit and configured to receive heat and transfer the heat to the refrigerant in the main flow circuit to output heated refrigerant flow. The system can include a passive pump (105) disposed in the main flow circuit downstream of the heat input configured to receive the heated refrigerant flow from the heat input and to use the heated refrigerant flow to generate a vacuum at a pump port (105a) and a condenser (107) disposed in the main flow circuit downstream of the passive pump for receiving flow from the passive pump. The condenser can be configured to receive heat from the heated refrigerant flow and reject heat to cool the heated refrigerant flow to output partially cooled refrigerant flow. An outlet (107a) of the condenser can be upstream of the heat input.