Gas Turbine Fuel Split Control for MWI Variations
Solution Overview
Problem
Gas turbine engine combustion systems face challenges in maintaining low NOx and CO emissions while accommodating variations in fuel composition and temperature, which can lead to combustion dynamics issues and require frequent retuning when fuel properties deviate from design values, limiting operational flexibility and efficiency.
Innovation Solution
A method and system for automatically adjusting fuel split schedules based on the Modified Wobbe Index (MWI) of the fuel, using sensors to determine fuel properties and algorithms to modulate fuel temperature and distribution, allowing for a wider range of fuel composition and temperature variations while maintaining emissions and dynamics within predetermined limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fuel nozzle gas areas are sized for a limited range of fuel MWI, then combustion dynamics and emissions are maintained within acceptable limits, but the system cannot accommodate larger variations in fuel composition without retuning
Solution Approach 1:
The fuel split schedules are made dynamically adjustable based on real-time MWI measurements. The system transitions from static nozzle designs to dynamic control where fuel distribution is continuously modified to accommodate varying fuel compositions while maintaining stable combustion dynamics and emissions within acceptable limits.
Solution Approach 2:
The system changes the fuel split parameter (distribution of fuel among multiple injection points) in response to changes in fuel MWI. By adjusting the fuel split schedule based on measured MWI values, the system adapts to different fuel compositions without requiring physical modification of the nozzle geometry.
2Reliability
If fuel schedule adjustments are made manually through tuning, then emissions and combustion dynamics are optimized, but the process requires special instrumentation and takes a day or longer to accomplish
Solution Approach 1:
The system performs self-adjustment by automatically measuring MWI and modifying fuel split schedules without requiring manual intervention from technicians. The automated control system continuously monitors combustion conditions and adjusts fuel distribution to maintain optimal emissions performance, eliminating the need for time-consuming manual tuning operations.
Solution Approach 2:
The system uses real-time MWI measurements and combustion monitoring data as feedback to automatically adjust fuel split schedules. This closed-loop control enables continuous optimization of emissions performance without requiring manual retuning, significantly reducing the time and expertise resources needed compared to traditional manual tuning processes.
3Adaptability or versatility
If fuel properties change by more than about plus or minus two percent in MWI, then fuel schedule adjustments are required, but frequent adjustments increase operational complexity and maintenance requirements
Solution Approach 1:
The automated control system serves multiple functions: it measures MWI, determines appropriate fuel split schedules, monitors combustion dynamics, and adjusts fuel distribution automatically. This multi-functional approach consolidates what would otherwise require multiple separate systems and manual processes into a single integrated control solution, reducing overall operational complexity.
Solution Approach 2:
The system replaces manual mechanical adjustment processes with automated electronic control. Instead of requiring technicians to physically adjust fuel schedules based on MWI changes, the system uses sensors, processors, and automated actuators to continuously monitor and adjust fuel distribution, simplifying the management complexity while maintaining adaptability to fuel property variations.
4Adaptability or versatility
If multiple independently controlled fuel injection points are used, then gas turbine operation from start-up through full load is enabled, but the system requires careful management of combustion conditions to achieve stable operation
Solution Approach 1:
The automated control system manages the complex coordination of multiple fuel injection points self-service manner. It continuously monitors combustion conditions across all injection points and automatically adjusts fuel distribution to maintain stable operation, eliminating the need for manual management of combustion conditions while enabling operation across the full operating range.
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
Enables continuous, cost-effective operation of gas turbine engines with varying fuel compositions and temperatures, reducing the need for frequent retuning and improving efficiency by automatically adjusting fuel splits and preheat temperatures, thus enhancing reliability and availability.
Implementation Method 1
raising the fuel gas temperature to cause it to have an MWI value equal to the design MWI
Implementation Method 2
determining the heating value and specific gravity of the fuel and computing the resulting the MWI
Implementation Method 3
modulate fuel temperature and distribution, allowing for a wider range of fuel composition and temperature variations while maintaining emissions and dynamics within predetermined limits
Data Source
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AI summary
Methods and systems for operating a gas turbine engine system (10) include an electrical generator (24) configured to provide electrical energy to a load, a gas turbine engine including at least one combustor (14) that includes a plurality of fuel injection points configured to inject a fuel into the combustor at a plurality of different locations wherein the combustor configured to combust the fuel and the gas turbine engine is rotatably coupled to the generator through a shaft. The gas turbine engine system includes a control system (18) including a plurality of sensors (26) positioned about the gas turbine engine system and configured to measure at least one parameter associated with the sensor, a processor programmed to receive a signal indicative of a heating value of the fuel, and automatically control a fuel split between the fuel injection points on the combustor using the determined heating value.