Hydraulic Fuel Control Valve for Gas Turbine Engine
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Solution Overview
Problem
Existing fuel control systems in gas turbine engines face challenges such as alignment issues, thermal growth, reliability problems due to dynamic seals, and difficulty in achieving accurate fuel valve position control in high-temperature environments, leading to potential fuel stagnation and degradation.
Innovation Solution
A fuel control arrangement utilizing a fuel injector coupled with a fuel control valve that receives fuel flow through a variable aperture port, operated by a hydraulic working fluid pressure source located remotely in a distinct temperature environment, ensuring precise control and continuous fuel circulation between primary and secondary fuel paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical systems use rods and unison ring to distribute and control fuel valves, then fuel delivery control is achieved, but physical alignment issues and thermal growth problems occur
Solution Approach 1:
The patent replaces the mechanical rod and unison ring system with a hydraulic control system using pilot pressure to distribute control of fuel through fuel valves. This substitution eliminates the need for physical alignment of mechanical components while maintaining fuel delivery control functionality.
Solution Approach 2:
The patent employs hydraulic control systems using pilot pressure to distribute control of fuel through fuel valves, replacing the mechanical system with fluid-based control that avoids alignment and thermal growth issues inherent in mechanical rod systems.
2Ease of operation
If hydraulic control systems use pilot pressure to distribute control of fuel, then mechanical alignment issues are eliminated, but additional fuel lines and supplies are required
Solution Approach 1:
The hydraulic pilot pressure system serves multiple functions: it controls fuel valve distribution and also provides the necessary pressure control for fuel flow regulation, reducing the need for separate dedicated pressure control systems and associated fuel lines.
3Reliability
If flexible drive actuation processes control individual fuel valves remotely, then control is achieved in high-temperature environments, but accurate sensing of fuel valve positions becomes difficult
Solution Approach 1:
The patent introduces hydraulic pilot pressure as an intermediary control mechanism that can be sensed and measured accurately without requiring direct contact with the high-temperature fuel valve environment, thereby maintaining measurement precision while achieving remote control.
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 accurate and reliable fuel control, preventing fuel stagnation and degradation by maintaining consistent fuel flow and circulation, enhancing system reliability and flexibility while reducing thermal issues.
Implementation Method 1
the working fluid pressure operating the control valve to alter the available aperture opening area of the variable port aperture dependent upon the working fluid pressure
Data Source
AI summary
Fuel control arrangements for gas turbine engines generally comprise an injector and a fuel control valve. Typically the fuel control valve is controlled in terms of fuel demand through fuel pressure presented to the valve. Fuel demand may vary and in such circumstances stagnation of fuel adjacent to the valve may cause degradation of the fuel and therefore spurious operational performance. By providing a dedicated working fluid, and typically hydraulic, pressure to the valve a variable aperture port can be displaced to alter the fuel flow configuration within the valve. In such circumstances different fuel valve conditions can be generated by altering the available area of aperture in the port to divert or present fuel to the injector between and across first or primary fuel paths and second or pilot fuel paths as required. Thus more flexibility with regard to fuel presentation to the injector is achieved as well as consistency with respect to avoiding fuel degradation as fuel demand varies.