Passive Refrigerant Tray Cooling for Aircraft Galley Carts

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Solution Overview

Problem

Conventional galley chillers used in aircraft for maintaining food items at low temperatures are heavy, noisy, consume significant power, and require complex and costly mechanical refrigeration units, which occupy valuable space and increase operational costs.

Innovation Solution

A passively cooled container system with a refrigerant tray that sublimates to produce cold gas, maintaining the container interior at temperatures below 4°C for extended periods without the need for mechanical refrigeration units, using vacuum insulated panels and a self-contained cooling unit within the galley cart.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional mechanical refrigeration units are used in galley carts, then cooling effectiveness is maintained, but weight increases and payload capacity is reduced

Engineering Contradiction:

Improvefood temperatureVSAvoidgalley cart weight

Core Design Contradiction:

TemperatureVSWeight of moving object

Solution Approach 1:

The patent replaces the mechanical refrigeration system with a chemical refrigerant system. The refrigerant absorbs heat from the food through phase change (evaporation) in closed loops, eliminating compressors, condensers, and other heavy mechanical components while maintaining effective cooling.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The refrigerant utilizes phase transitions (evaporation from liquid to gas) to absorb heat from the food. This phase change process provides efficient cooling without requiring mechanical work, thereby reducing the weight of the cooling system.

Inventive Principle:

Principle #36Phase transitions

2Temperature

If conventional mechanical refrigeration units are used in galley carts, then cooling capability is provided, but noise increases and passenger comfort is reduced

Engineering Contradiction:

Improvefood temperatureVSAvoidnoise

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The mechanical components that generate noise (compressors, fans, motors) are replaced with a passive chemical refrigeration system. The refrigerant circulates through capillary tubes or expansion devices without mechanical power sources, eliminating noise generation while maintaining cooling capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Temperature

If conventional mechanical refrigeration units are used in galley carts, then cooling function is achieved, but space is occupied and cabin area is reduced

Engineering Contradiction:

Improvefood temperatureVSAvoidgalley cart volume

Core Design Contradiction:

TemperatureVSVolume of moving object

Solution Approach 1:

The bulky mechanical refrigeration units (compressors, condensers, evaporators, ducting) are replaced with compact refrigerant loops integrated within the galley cart structure. This chemical refrigeration approach reduces the volume required for cooling by over 50% compared to mechanical systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Temperature

If conventional mechanical refrigeration units are used in galley carts, then cooling performance is maintained, but manufacturing and installation costs increase

Engineering Contradiction:

Improvefood temperatureVSAvoidmanufacturing cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The complex mechanical refrigeration system with multiple moving parts, seals, and control mechanisms is replaced with a simpler chemical refrigeration system using refrigerant loops and phase change materials. This reduces manufacturing complexity and cost while maintaining cooling effectiveness.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

5Temperature

If conventional mechanical refrigeration units are used in galley carts, then cooling capability is provided, but power consumption increases and payload capacity is reduced

Engineering Contradiction:

Improvefood temperatureVSAvoidpower consumption

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The mechanical refrigeration system that consumes electrical power for compression and circulation is replaced with a passive chemical refrigeration system. The refrigerant absorbs and releases heat through phase changes without requiring external power input, eliminating power consumption entirely.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

6Temperature

If conventional mechanical refrigeration units are used in galley carts, then cooling function is achieved, but device complexity increases and maintenance requirements increase

Engineering Contradiction:

Improvefood temperatureVSAvoidrefrigeration system complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The complex mechanical system with compressors, valves, sensors, and control circuits is replaced with a simple chemical refrigeration system using closed-loop refrigerant circulation and phase change. This eliminates mechanical complexity and reduces maintenance requirements to minimal monitoring of refrigerant levels.

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

The system effectively maintains food items at safe temperatures for up to 15 hours, reducing weight, noise, and operational costs while minimizing space usage and eliminating the need for complex refrigeration systems.

Implementation Method 1

The refrigerant may produce a cold gas upon sublimation of the refrigerant

Methodology Applied

Scientific EffectSublimation: Sublimation

Implementation Method 2

using vacuum insulated panels and a self-contained cooling unit within the galley cart

Methodology Applied

Scientific EffectThermal Insulation: Thermal Insulation

Data Source

PatentUS9303912B1Passively cooled container system and method

Publication Date: 2016.04.05 THE BOEING CO

AI summary

A container system may comprise a container, a refrigerant tray, and refrigerant. The container may have a container interior. The refrigerant tray may be mountable within the container interior and may include a sublimation port. The refrigerant may be mounted within the refrigerant tray. The refrigerant may produce a cold gas upon sublimation of the refrigerant. The cold gas may pass through the sublimation port and enter into the container interior.