Gas Turbine Combustor Mixing Devices with Varying Lance Tip Positions
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Solution Overview
Problem
Combustion devices in gas turbines face pressure pulsations due to non-uniform temperature distribution across mixing devices, leading to reduced longevity of components and complex fuel control challenges.
Innovation Solution
The combustion device features mixing devices with conical bodies and lances of varying tip positions, allowing for uniform operation temperature and simplified fuel control, thereby damping pressure oscillations without the need for temperature adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If mixing devices are operated at different temperatures to damp pressure pulsations, then pressure pulsations are reduced, but temperature uniformity deteriorates and component stress increases
Solution Approach 1:
The patent applies local quality by varying the lance tip position in different mixing devices within the same group. Specifically, mixing devices have lance tips at different distances from the conical body open end, creating local geometric variations that modify pressure oscillation characteristics without affecting temperature distribution. This allows pressure pulsation damping while maintaining uniform temperature across all mixing devices.
Solution Approach 2:
The patent changes the geometric parameter of the lance tip position to control pressure oscillations. By adjusting the distance of the lance tip from the conical body open end, the patent modifies the acoustic resonance characteristics of each mixing device, enabling pressure pulsation damping through geometric parameter variation rather than temperature adjustment.
2Object-affected harmful factors
If mixing devices are operated at different temperatures to damp pressure pulsations, then pressure pulsations are reduced, but device complexity increases due to differential fuel control
Solution Approach 1:
The patent uses local quality by implementing geometric variations (different lace tip positions) in individual mixing devices rather than operational variations (different temperatures). This geometric differentiation allows each mixing device to have unique pressure oscillation characteristics while maintaining uniform operational parameters, including temperature and fuel composition, thereby simplifying the fuel control system.
Solution Approach 2:
The patent replaces the thermal control mechanism (differential fuel adjustment to create temperature differences) with a geometric mechanism (fixed lance tip position variations). This substitution eliminates the need for complex real-time fuel control adjustments across different mixing devices, as the pressure pulsation damping is achieved through static geometric configuration rather than dynamic operational control.
3Object-affected harmful factors
If lance tips are positioned at different distances, then pressure oscillations are damped, but manufacturing precision requirements increase
Solution Approach 1:
The patent deliberately changes the geometric parameter of lance tip position to achieve pressure pulsation damping. While this does require manufacturing precision, the patent addresses this by establishing clear design criteria for the distance variations and incorporating these specifications into the manufacturing process, transforming a potential precision challenge into a controlled design parameter.
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 configuration enhances the lifetime of combustion devices and rotor blades by maintaining uniform temperature and simplifying fuel control across all operating conditions, reducing stress and operational complexity.
Implementation Method 1
The lance tips of different mixing devices have different distances from the open end of the corresponding conical body, respectively... This configuration enhances the lifetime of combustion devices and rotor blades by maintaining uniform temperature and simplifying fuel control across all operating conditions, reducing stress and operational complexity.
Data Source
AI summary
A combustion device includes a plurality of mixing devices into which a fluid containing oxygen and a fuel are introduced and mixed to form a mixture. The combustion device also includes a combustion chamber in which the mixture formed in the mixing devices is burnt. Each mixing device has a conical body with a lance projecting into the conical body, where the fuel is injectable into the conical body. Tips of the lances of different mixing devices have different distances from corresponding open ends of the respective conical bodies.