Staged Combustion Fuel Distribution for Gas Turbine Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine combustion chambers with staged combustion designs experience non-uniform combustion efficiency at low speeds and low power conditions, leading to lower efficiency in some scenarios due to the limited use of pilot fuel nozzles.
Innovation Solution
The method involves an annular combustion chamber with pilot and main fuel nozzles, where fuel distribution is optimized by supplying a greater amount to pilot nozzles than main nozzles in certain regions and switching modes based on temperature and power conditions, using fuel flow restrictors and valves to adjust fuel flow according to predetermined pressures and temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pilot fuel nozzles are used only during low speed and low power conditions, then combustion stability is maintained during idle and approach, but combustion efficiency becomes non-uniform across different low speed conditions
Solution Approach 1:
The system dynamically switches between different fuel nozzle configurations based on operating conditions. During low speed/low power conditions, fuel is supplied to pilot nozzles only. During high speed/high power conditions, fuel is supplied to both pilot and main nozzles. This dynamic adaptation resolves the contradiction by optimizing combustion efficiency across different operating regimes while maintaining combustion stability when required.
Solution Approach 2:
The invention changes the fuel distribution parameters by introducing multiple fuel supply modes. The first mode supplies fuel only to pilot nozzles at low speeds, while the second mode supplies fuel to both pilot and main nozzles at high speeds. This parameter change enables uniform combustion efficiency across all operating conditions while preserving combustion stability during critical low speed operations.
2Productivity
If fuel is supplied equally to pilot and main fuel nozzles at high speed conditions, then combustion efficiency is optimized, but NOX production increases
Solution Approach 1:
The system applies different fuel distribution strategies to different nozzle groups based on local combustion requirements. During high speed conditions, fuel is distributed between pilot and main nozzles in specific ratios that optimize combustion efficiency while controlling peak temperatures. This localized control of fuel-air mixture quality reduces NOX formation while maintaining efficient combustion.
3Productivity
If staged combustion with separate pilot and main fuel nozzles is used, then combustion efficiency is improved, but device complexity increases
Solution Approach 1:
The fuel nozzle system is designed with multi-functionality where the same physical nozzles serve different purposes under different operating conditions. The pilot nozzles provide both stabilization function at low speeds and contribute to efficient combustion at high speeds. This universal design reduces overall system complexity while maintaining high combustion efficiency across all operating regimes.
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 enhances combustion efficiency and maintains desirable combustion product limits across varying conditions by optimizing fuel distribution and nozzle operation, improving performance at low speeds and low power conditions.
Implementation Method 1
fuel flow restrictors in the pilot fuel nozzles at, or in, the first circumferential region of the annular combustion chamber being arranged to open at a first predetermined pressure and the pilot fuel nozzles at, or in, the second circumferential region of the annular combustion chamber being arranged to open at a second predetermined pressure
Implementation Method 2
staged combustion of the fuel
Implementation Method 3
optimizing fuel distribution and nozzle operation, improving performance at low speeds and low power conditions
Data Source
AI summary
A combustion chamber system has pilot and main fuel manifolds, and pilot and main fuel nozzles. Each pilot nozzle is connected to the pilot manifold. Each main nozzle is connected to the main manifold. A greater total amount of fuel is supplied to the pilot nozzles than to the main nozzles. A greater amount of fuel is supplied to pilot nozzles at, or in, a first region of the combustion chamber than to pilot fuel nozzles at, or in, a second region. A greater amount of fuel is supplied to the main nozzles at, or in, the first region than to the main nozzles at, or in, the second to improve combustion efficiency, weak extinction and relight of the combustion chamber in a first mode of operation. A greater total amount of fuel is supplied to the main nozzles than to the pilot nozzles in a second mode of operation.