Fuel Injector Purging via Selective Manifold Bypass
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Solution Overview
Problem
Gas turbine engine fuel manifolds often require purging to prevent 'coking' of fuel injectors, which is inefficient as traditional methods involve substantial air usage and leave the manifold full of fuel, posing operational and environmental challenges.
Innovation Solution
The method involves selectively disconnecting primary and secondary fuel passages from the fuel manifold and injecting a purging fluid, such as compressed air, directly into the passages while bypassing the manifold, using electro-mechanical valves to control the flow and pressure, allowing for efficient purging of only the fuel injectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional purging methods are used to empty the fuel manifold, then fuel residue burning on nozzles is prevented, but substantial air usage is required and the manifold is left empty
Solution Approach 1:
The fuel injector is divided into separate primary and secondary fuel passages that can be independently purged. The flow divider valve separates the fuel flow paths, allowing selective purging of one passage while maintaining fuel supply through the other passage, thereby reducing overall air consumption during purging operations
Solution Approach 2:
Instead of purging the entire fuel manifold system, the invention applies partial purging only to the specific fuel passages that require cleaning. The flow divider valve enables selective isolation and purging of individual passages, performing exactly the necessary action without excessive air usage on the entire system
2Reliability
If the fuel manifold is purged to prevent coking, then nozzle durability is improved, but the manifold is left full of fuel which creates operational challenges
Solution Approach 1:
The fuel system is segmented into multiple independent passages with separate purging capabilities. After purging one passage, fuel can be immediately reintroduced through that same passage without requiring manual intervention, while other passages continue to operate normally
Solution Approach 2:
The flow divider valve is positioned to allow automatic refilling of purged passages. After a passage is purged, the valve configuration enables fuel to automatically flow back into the passage without requiring manual refilling operations, maintaining system readiness
3Loss of substance
If traditional purging methods are used, then fuel passages are cleaned, but fuel waste occurs and environmental regulations are difficult to comply with
Solution Approach 1:
The invention implements partial purging that targets only the specific passages containing fuel residue, rather than purging the entire manifold system. This selective approach minimizes fuel waste by leaving fuel in passages that are still functional and do not require cleaning
Solution Approach 2:
The flow divider valve enables the system to recover and maintain fuel in the manifold by selectively isolating only the passages that need purging. Fuel remaining in the manifold and non-purged passages can be recovered and reused, reducing overall fuel waste and improving environmental compliance
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 approach reduces the amount of air required for purging, minimizes fuel waste, maintains the manifold filled with fuel, and effectively prevents nozzle coking, enhancing operational efficiency and compliance with environmental regulations.
Implementation Method 1
purging the one or more of the primary and secondary fuel passages by injecting a purging fluid into the one or more of the primary and secondary fuel passages
Data Source
AI summary
A method of purging fuel injectors of a gas turbine engine, the fuel injectors fluidly connected to a fuel manifold and having primary and secondary fuel passages fluidly connectable to the fuel manifold, the method includes: selectively fluidly disconnecting one or more of the primary and secondary fuel passages from the fuel manifold; and purging the one or more of the primary and secondary fuel passages by injecting a purging fluid into the one or more of the primary and secondary fuel passages while bypassing the fuel manifold. A fuel injector having two fuel passages, a flow divider valve, and a purging valve is disclosed.