Multi-shaft Gas Turbine Combustor Control via Real-time Flow Calculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional combustion control methods for multi-shaft gas turbines face challenges in precisely measuring high-temperature and high-pressure state quantities, making it difficult to estimate combustion temperature and control the fuel-air ratio for stable combustion, especially when combustion air flow and fuel flow changes are independent.
Innovation Solution
A combustor control method and controller that calculates combustion air flow and fuel flow based on the open position of compressor inlet guide vanes, turbine speeds, and atmospheric temperature, using an ignition/extinction control unit to determine a real-time fuel-air ratio for stable combustion, without requiring complex calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional combustion control methods estimate combustion temperature from state quantities, then combustion mode switching can be achieved, but measurement precision deteriorates due to difficulty in measuring high-temperature and high-pressure state quantities immediately and precisely
Solution Approach 1:
The patent introduces an intermediary calculation approach that avoids direct measurement of difficult-to-measure state quantities. Instead of measuring high-temperature and high-pressure state quantities directly, the system calculates combustion air flow from compressor inlet guide vane position and revolution speed, and calculates fuel flow from power turbine revolution speed, then derives combustion temperature from these calculated flows. This intermediary calculation chain resolves the measurement precision problem.
Solution Approach 2:
The patent replaces the mechanical measurement system (direct measurement of high-temperature and high-pressure state quantities) with a calculation-based system. By substituting physical measurement with mathematical calculation based on easily measurable parameters (IGV position, revolution speeds), the system achieves reliable combustion temperature estimation without the limitations of direct measurement.
2Stability of the object's composition
If systematic combustion transferring method based on fuel flow demand is used, then stable combustion can be achieved, but adaptability deteriorates because combustion air flow changes continuously depending on gas generator turbine operation and cannot be considered
Solution Approach 1:
The patent implements feedback control by continuously calculating both combustion air flow (from IGV position and gas generator revolution speed) and fuel flow (from power turbine revolution speed), then using these real-time calculated values to determine the fuel-air ratio. This feedback mechanism ensures that combustion control adapts to continuous changes in combustion air flow while maintaining stable combustion, resolving the contradiction between stability and adaptability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided are a combustor control method and a combustor controller capable of calculating the combustion air flow and the fuel flow in multi-shafts gas turbine with high precision and without the need of performing complicated calculations and thereby calculating a fuel-air ratio necessary for stable combustion control. The multi-shaft gas turbine is made up of a gas generator turbine 110 and a power turbine 120. A combustor 114 includes a diffusive combustion unit F1 and a plurality of premixed combustion units F21 - F24. An ignition/extinction control unit 220 of the combustor control device calculates the combustion air flow supplied to the combustor 114 based on the open position of compressor inlet guide vanes 112A attached to the gas generator turbine 110, revolution speed of the gas generator turbine 110 and compressor inlet temperature, calculates the flow of fuel supplied to the combustor 114 based on revolution speed of the power turbine 120, and calculates the fuel-air ratio in real time as flame reference based on the calculated combustion air flow and fuel flow.