Flexible Fluid Container for Fuel Tank Explosion Risk Reduction

Solution Overview

Problem

Existing safety systems for reducing explosion risk in aircraft fuel tanks, such as using oxygen-depleted air, increase aircraft weight due to the need for condensation devices and result in kerosene vapor emissions, which are costly and inefficient.

Innovation Solution

A flexible fluid container is positioned in the fuel tank's hollow space above the fuel, occupying it and preventing the formation of flammable mixtures by flowing fluid through an inlet and outlet, with optional pressure relief valves and condensation features to manage humidity and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oxygen-depleted air is used as protective gas, then explosion risk is reduced, but aircraft weight increases due to condensation devices

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent extracts and removes the harmful water component from the oxygen-depleted air through a condensation device, separating the useful protective gas function from the harmful humidity. This allows the system to maintain explosion protection while managing the weight penalty of the condensation device through efficient water removal and potential reuse.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent recovers and reuses the water condensed from the protective gas for other purposes on the aircraft, such as toilet flushing or cooling systems. This recovery approach justifies the weight of the condensation device by converting a waste product into a useful resource, reducing overall system weight penalties.

Inventive Principle:

Principle #34Discarding and recovering

2Reliability

If protective gas system is implemented, then explosion risk is reduced, but kerosene vapor emissions occur

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potentially harmful kerosene vapors that would normally be emitted during ventilation into a beneficial resource by directing them through the fuel cell system where they are combusted to generate electricity. This eliminates harmful emissions while producing useful energy.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The fuel cell acts as an intermediary device between the protective gas system and the atmosphere, capturing kerosene vapors that would otherwise be emitted and processing them through controlled combustion. This intermediary function transforms the emission problem into an energy generation opportunity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If condensation devices are added to dehumidify protective gas, then fuel quality is maintained, but device complexity increases

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The condensation device is integrated with multiple functions: it dehumidifies the protective gas to maintain fuel quality, recovers water for reuse, and works in conjunction with the fuel cell system for energy generation. This multi-functionality reduces overall system complexity by combining what would otherwise be separate systems.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the condensation device with the existing fuel cell and ventilation systems, combining multiple functions into an integrated assembly. This reduces device complexity by eliminating separate standalone systems and creating a unified multi-functional unit.

Inventive Principle:

Principle #5Merging (Combining)

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 reduces explosion risk, minimizes kerosene vapor emissions, and decreases aircraft weight by eliminating the need for conventional ventilation systems and condensation devices, while ensuring thermal expansion is managed without tank damage.

Implementation Method 1

fluid flows into the hollow space essentially occupying the space up to the top of the fuel tank

Methodology Applied

Scientific EffectFluid flow:

Implementation Method 2

As a result of the fluid flowing in, and of the fluid initially flowing out with a delay as a result of the limited flow-through aperture of the outlet, the fluid container extends

Methodology Applied

Scientific EffectHydraulic expansion:

Implementation Method 3

prevents a situation in which at the interface between the fuel and the hollow space a flammable mixture forms, because there is practically no free air volume present

Methodology Applied

Scientific EffectGas displacement:

Data Source

PatentUS8727282B2Safety system for reducing the explosion risk of a fuel tank

Publication Date: 2014.05.20

AI summary

A safety system for reducing the explosion risk of a fuel tank comprises at least one fluid source and at least one fluid container with an inlet and an outlet for a fluid, wherein the fluid container has a structure that is flexible at least in some regions and is designed in such a manner that it can be positioned in a hollow space of the fuel tank, which hollow space is situated above the fuel, with said fluid container when fluid flows into the hollow space essentially occupying the space up to the top of the fuel tank. In this way it is possible to avoid the presence of a free air volume in the fuel tank, which counteracts any formation of a potentially explosive mixture and in this way reduces the explosion risk.