Aircraft Galley Cooling Interlock for Evaporator Freeze Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing aircraft galley chilling systems face issues when cart bay doors are left open, allowing ambient moisture and warm air to enter, causing the evaporator to freeze and leading to temperature fluctuations that can render food cart contents hazardous.

Innovation Solution

An interlock system using active sensors, such as reflective light sensors or Hall Effect sensors, is implemented to detect when the cart bay door is open, sending a signal to deactivate the chilling unit, preventing warm air and moisture from entering the chilled compartment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the cart bay door is left open for access or service, then ease of operation is improved, but moisture and warm air enter the compartment causing the evaporator to freeze and chilling system failure

Engineering Contradiction:
Improvedoor accessVSAvoidchilling system operation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The sensor detects door opening in advance and triggers the processor to shut off the chilling unit before moisture and warm air can cause the evaporator to freeze. This preliminary action prevents the harmful effect from occurring in the first place

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sensor provides continuous feedback about door status to the processor, which automatically adjusts the chilling unit operation accordingly. When the door is detected as open, the system responds by shutting off the chilling unit to prevent evaporator freezing

Inventive Principle:
Principle #23Feedback

2Temperature

If the chilling unit operates continuously to maintain temperature, then temperature stability is improved, but warm air intrusion when door is open causes evaporator freezing and system shutdown

Engineering Contradiction:
Improvetemperature stabilityVSAvoidmoisture intrusion
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The system applies preliminary anti-action by shutting off the chilling unit before moisture from ambient air can contact the evaporator and cause freezing. The sensor detects door opening and triggers immediate shutdown to counteract the harmful effect before it occurs

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The sensor-processor system provides feedback control by monitoring door status and automatically adjusting chilling unit operation. When the door is detected as open, the system responds by shutting off the chilling unit to prevent evaporator freezing while maintaining temperature stability when the door is closed

Inventive Principle:
Principle #23Feedback

3Reliability

If a sensor-based interlock system is added to detect door status, then reliability is improved by preventing evaporator freezing, but device complexity increases

Engineering Contradiction:
Improvechilling system operationVSAvoidinterlock system components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical interlock systems with a sensor-based detection system that uses optical or magnetic fields to detect door status. This substitution reduces mechanical complexity while improving reliability through automatic electronic control of the chilling unit

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

Effectively prevents the evaporator from freezing and maintains optimal temperatures by shutting off the chilling unit when the compartment is open, ensuring food safety and extending the operational life of the chilling system.

Implementation Method 1

An interlock system using active sensors, such as reflective light sensors

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

An interlock system using active sensors, such as reflective light sensors or Hall Effect sensors

Methodology Applied
Scientific EffectHall Effect: Hall Effect

Data Source

PatentEP2920074B1Aircraft galley compartment cooling system with door lock sensor
Publication Date: 2019.01.09 BE AEROSPACE INC
  • EP2920074B1 patent drawingFigure 1~2
  • EP2920074B1 patent drawingFigure 3A~3B
  • EP2920074B1 patent drawingFigure 4~6

AI summary

An aircraft galley compartment cooling system includes a source of chilled air (100), and a closed compartment (80) with a door (90). A sensor (120) detects the opening of the door (90), and sends a signal to a processor (220) to deactivate a chiller (230) while the door is opened to prevent ambient air from entering the cooling system. Once the door is closed, the chiller is reactivated. The sensor (120) can be a light sensor (180), a mechanical sensor, a magnetic sensor, or the like for determining movement or the presence/non-presence of the door (90) to the compartment.