Dynamic Diluent Control for Gas Turbine Emission Reduction
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Solution Overview
Problem
Conventional combustion systems face challenges in maintaining low emissions of greenhouse gases like CO2 and air pollutants such as NOX, particularly due to dynamic load changes and rapid fuel heating value variations, which can lead to undesirable turbulence and flameout when using high diluent-to-fuel ratios.
Innovation Solution
A dynamic control system that actively adjusts the flow of chemically inactive diluents like nitrogen, CO2, or steam to achieve a homogeneous diluent-to-fuel ratio, ensuring emissions remain below desired levels by continuously monitoring flow parameters and using static mixers and control valves to maintain optimal mixing homogeneity above 97.5%, thereby stabilizing the flame and reducing NOX emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If high diluent-to-fuel ratios are used to achieve low emissions, then emissions levels are reduced, but turbulence and flameout occur due to dynamic load changes and fuel heating value variations
Solution Approach 1:
The system employs dynamic control mechanisms that continuously adjust diluent flow rates in response to real-time changes in load and fuel heating value. The controller modifies the diluent-to-fuel ratio dynamically to maintain optimal mixing conditions, preventing turbulence and flameout while sustaining low emissions throughout varying operating conditions
Solution Approach 2:
The system incorporates feedback control by monitoring combustion parameters and adjusting diluent flow accordingly. Sensors detect changes in combustion stability and emissions, and the controller responds by modifying diluent injection rates to maintain flame stability and prevent emissions spikes during dynamic load changes
2Object-generated harmful factors
If diluent flow is increased to maintain low emissions during dynamic load changes, then emissions control is improved, but system complexity increases due to continuous monitoring and control requirements
Solution Approach 1:
The control system is designed to perform multiple functions through a single integrated controller that manages diluent flow control, mixing optimization, and emissions monitoring. The system handles various operating conditions (different loads, fuel types, and heating values) through universal control algorithms rather than requiring separate control mechanisms for each scenario
Solution Approach 2:
The system incorporates self-regulating characteristics where the control algorithm automatically adjusts diluent flow based on real-time combustion conditions without requiring external manual intervention. The feedback mechanism enables the system to self-correct deviations in emissions and flame stability, reducing the need for complex external control systems
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
The system effectively reduces NOX emissions to below 2 ppm and CO2 emissions per kilowatt hour, while increasing power output and maintaining flame stability even at high steam-to-fuel ratios, demonstrating improved efficiency and compliance with emission regulations.
Implementation Method 1
The apparatus comprises a static mixer element and preferably a Cheng rotation vane element where the combined effect of these elements produces a mixture with homogeneity preferably higher than 99%
Implementation Method 2
combustion of said mixture produces emissions below a desired level
Data Source
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AI summary
A method and apparatus for the reduction of undesirable emissions in a gas turbine combustion system, said method comprising: delivering and homogenously mixing diluent (1) and fuel (2) and introducing the mixture (3) into a flame zone for combustion; and dynamically controlling the flow of diluent to be homogenously mixed with said fuel while maintaining a diluent-to-fuel ratio of said homogenized mixture (3) above 3.0:1 to produce reduced emissions of CO, NOx and CO2, as compared to combustion of a homogenous mixture of diluent and fuel at diluent-to-fuel ratios below 3.0:1.