Auto-thermal Valve for Gas Turbine Fuel Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbines face challenges in reducing NOx emissions and efficiently controlling fuel flow to axial fuel stages, particularly at varying operational loads, which affects combustion efficiency and emissions.
Innovation Solution
A passively-actuated, thermally-actuated auto-thermal valve that directs fuel flow to an axial fuel stage based on the temperature of the fuel, ensuring optimal fuel injection and emission control by opening or closing in response to temperature set points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a passive valve is used to control fuel flow to axial fuel stage, then device complexity is reduced, but fuel flow control precision deteriorates
Solution Approach 1:
The valve operates by detecting changes in fuel temperature parameter and automatically adjusting its opening degree accordingly. The thermal response characteristic of the valve is designed to match the desired fuel flow control profile, enabling precise control through temperature-driven actuation without complex mechanical or electronic control systems.
Solution Approach 2:
The valve system is self-regulating, using the inherent thermal properties of the fuel itself as the control signal. The fuel temperature naturally varies with operating conditions, and the valve automatically responds to these temperature changes to regulate fuel flow, eliminating the need for external control mechanisms.
2Manufacturing precision
If active control systems are used for fuel flow control, then fuel flow control precision is improved, but device complexity increases
Solution Approach 1:
The invention replaces complex mechanical or electronic active control systems with a thermally-actuated passive valve. The control function is achieved through thermal field interaction rather than mechanical actuation or electronic signaling, simplifying the overall system architecture while maintaining control precision.
Solution Approach 2:
Fuel temperature serves as an intermediary parameter that indirectly controls fuel flow. Instead of directly actuating the valve through mechanical or electronic means, the system uses temperature changes in the fuel as a mediator to automatically regulate valve opening, simplifying the control mechanism.
3Productivity
If fuel temperature is increased to improve combustion efficiency, then combustion efficiency is improved, but NOx emissions increase
Solution Approach 1:
The system dynamically adjusts fuel flow to the axial fuel stage based on real-time fuel temperature conditions. The valve opening degree varies continuously with temperature changes, enabling the system to adapt combustion conditions to minimize NOx formation while maintaining efficient combustion. This dynamic control allows optimization of the trade-off between combustion efficiency and emissions.
Solution Approach 2:
The axial fuel stage provides a controlled partial injection of fuel into the combustion zone, rather than full injection. This partial action approach allows the system to achieve sufficient combustion efficiency while limiting the total fuel quantity that could potentially form NOx, thereby controlling emissions levels.
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 enhances combustion efficiency and reduces NOx emissions by allowing precise control of fuel flow to axial fuel stages, improving turndown capability and emissions compliance without requiring extensive fuel circuit upgrades, thus offering a cost-effective solution for existing gas turbines.
Implementation Method 1
a passively-actuated valve for selectively directing a supply of fuel to the axial fuel stage fuel injector based on a characteristic of the fuel; the passively-actuated valve comprises a thermally-actuated valve
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A combustor 11 for a gas turbine, including: an axial fuel stage fuel injector 62; and a passively-actuated valve 66 for selectively directing a supply of fuel 64 to the axial fuel stage fuel injector based on a characteristic of the fuel.