Active Spool Control for Secondary Nozzle Fuel Scheduling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fuel injectors with passive flow scheduling valves in gas turbine engines face challenges in noise reduction and structural integrity due to natural frequency excitation, requiring costly and weight-intensive adjustments to fuel manifolds and flow dividers.
Innovation Solution
The system incorporates a solenoid valve connected to a hydromechanical valve spool in the injector, allowing for active regulation of flow through primary and secondary circuits, enabling precise control of fuel flow and reducing noise by varying the flow area based on electrical power applied to the solenoid valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If passive flow scheduling valves are used in fuel injectors, then the system is simple and reliable, but noise increases due to natural frequency excitation and structural stress occurs
Solution Approach 1:
The patent replaces the purely mechanical passive flow scheduling valve with an electrohydraulic system. A solenoid valve (electrical component) controls hydraulic pressure to a spool in the flow scheduling valve assembly, enabling active control of fuel flow. This substitution allows precise regulation of flow area to decouple heat release from combustor natural frequency, reducing noise and structural stress while maintaining system reliability through fail-safe passive operation capability.
Solution Approach 2:
The patent introduces a solenoid valve as an intermediary control element between the electrical control system and the hydraulic fuel flow. The solenoid valve modulates control pressure that acts on the spool of the flow scheduling valve, providing indirect but precise control over fuel flow area. This intermediary approach enables active patternation of fuel injection to mitigate noise without requiring direct mechanical modification of the main fuel path.
2Object-affected harmful factors
If adjustments to fuel scheduling are made to decouple heat release and noise, then noise is reduced, but additional flow dividing hardware and fuel manifolds are required adding significant cost, weight, and power requirements
Solution Approach 1:
The patent makes the flow scheduling valve assembly multi-functional by integrating both passive flow scheduling capability and active noise control functionality into a single component. The spool within the flow scheduling valve assembly can operate in two modes: passive operation based solely on inlet pressure (original function) and active operation controlled by solenoid-modulated hydraulic pressure (noise control function). This eliminates the need for separate flow dividing hardware and multiple fuel manifolds, reducing weight while achieving noise reduction.
Solution Approach 2:
The patent merges the solenoid valve control system with the existing flow scheduling valve assembly. The solenoid valve connects to the control port of the flow scheduling valve spool, combining electrical control capability with the hydraulic flow scheduling mechanism. This integration allows the system to achieve active noise control without adding separate flow dividing hardware, fuel manifolds, or independent control systems, thereby minimizing additional weight and cost.
3Object-affected harmful factors
If adjustments to fuel scheduling are made to decouple heat release and noise, then noise is reduced, but significant power requirements are added
Solution Approach 1:
The patent uses hydraulic amplification to reduce power requirements. The small solenoid valve controls a relatively large spool in the flow scheduling valve assembly by modulating hydraulic pressure. The hydraulic fluid acts as a force amplifier, allowing the low-power solenoid to move the higher-inertia spool against spring forces and fuel pressure. This hydraulic intermediary reduces the electrical power requirement compared to directly actuating the main fuel flow valve electrically.
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 provides active patternation in fuel injection, reducing noise and structural stress without adding significant weight or power requirements, allowing for efficient and controlled fuel distribution in gas turbine engines.
Implementation Method 1
a solenoid valve member configured to control flow through the solenoid valve from the inlet to the outlet based on electrical power applied to an armature of the solenoid valve
Implementation Method 2
The valve spool can be biased to a closed position by one or more biasing members of the scheduling valve assembly
Data Source
AI summary
A system includes an injector having a scheduling valve assembly and a nozzle in fluid communication with the valve assembly. The scheduling valve assembly is configured for regulation of flow from an inlet of the injector to the nozzle. The injector includes two fluid circuits between the inlet of the injector and two respective outlets of the nozzle for staged flow output from the nozzle. A first one of the two fluid circuits is a primary circuit, and a second one of the two fluid circuits is a secondary circuit. A solenoid valve is connected in fluid communication with the scheduling valve assembly, wherein the solenoid valve is configured to adjust position of a hydromechanical valve spool of the valve assembly.