Aircraft Engine Fluid Shutoff Valve for Fire Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft engine components certified as fireproof are more costly, larger, heavier, and more complex than those certified as fire resistant, as they need to prevent leakage of flammable fluids for an additional ten minutes beyond the five-minute fire resistance requirement, making it desirable to utilize fire-resistant components instead.
Innovation Solution
Incorporating a thermal shutoff valve with a deformable member made of shape-memory alloy in the fluid system, which changes shape in response to increased temperature, disconnecting the fluid source from the component during a fire event to prevent fluid leakage, thereby allowing the use of fire-resistant components that only need to comply with five-minute fire resistance requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fireproof certification is applied to aircraft engine components, then safety is improved by preventing flammable fluid leakage for 10 minutes beyond fire resistance, but cost, size, weight, and complexity increase significantly
Solution Approach 1:
The system separates fire protection into two independent parts: (1) fire-resistant components that survive 5 minutes of fire exposure, and (2) a thermal shutoff valve that closes at elevated temperatures to stop flammable fluid flow. This segmentation allows using simpler, less expensive fire-resistant components instead of complex fireproof components while achieving equivalent safety.
Solution Approach 2:
The thermal shutoff valve acts as an intermediary device between the flammable fluid source and the component. When fire occurs, the valve closes to interrupt fluid flow, protecting the component from both fire exposure and fluid leakage. This intermediary approach enables use of fire-resistant rather than fireproof components.
2Reliability
If fireproof components are used to prevent flammable fluid leakage during extended fire exposure, then safety is improved, but weight increases
Solution Approach 1:
The fire protection function is divided between the fire-resistant component (surviving 5 minutes) and the thermal shutoff valve (stopping fluid flow). This segmentation allows using lighter fire-resistant components instead of heavier fireproof components while maintaining safety through the valve mechanism.
3Reliability
If fireproof certification is implemented to ensure no hazardous fluid leakage for 10 additional minutes, then safety is improved, but manufacturing cost increases
Solution Approach 1:
The system divides fire protection into two functions: fire-resistant component design (5-minute survival) and thermal shutoff valve (fluid flow interruption). This segmentation enables use of less expensive fire-resistant components with added valve protection, reducing overall manufacturing cost compared to fireproof certification.
Solution Approach 2:
The thermal shutoff valve automatically closes in response to temperature increase during fire events without requiring external control systems. This self-actuating mechanism reduces complexity and cost compared to electronically controlled valves while ensuring safety.
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
This solution effectively reduces the complexity and cost of fire-resistant components by ensuring they do not leak hazardous amounts of flammable fluid during a fire, simplifying compliance with regulations and avoiding the need for fireproof certification.
Implementation Method 1
a deformable member made of shape-memory alloy in the fluid system, which changes shape in response to increased temperature
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An aircraft engine, has: a fluid system (30) including a fluid circuit (33) fluidly connecting a plurality of components to a source (31) of a fluid, the fluid being flammable, a component (35) of the plurality of components containing a volume of the fluid during normal operation; and a valve (70) fluidly connected to the fluid circuit (33) upstream of the component (35) relative to a flow of the fluid towards the component (35), the valve (70) having an open configuration fluidly connecting the source (31) of the fluid to the component (35) through the valve (70) and a closed configuration in which the valve (70) disconnects the source (31) of the fluid from the component (35), the valve (70) movable from the open configuration to the closed configuration in response to the component (35) being subjected to a fire event.