Blow-off Valve Control for Gas Turbine De-loading Stability
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Solution Overview
Problem
Gas turbines face instability in the combustion chamber during sudden de-loading events, such as load rejection, leading to potential flame stabilization issues.
Innovation Solution
A blow-off valve assembly is used to establish fluid communication between the compression stage and the flue gas exhaust stage, controlled by a system that detects sudden de-loading and activates the valve to maintain stability, allowing for controlled fluid flow and pressure management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the blow-off valve remains closed during sudden de-loading, then the pressure in the compression stage is maintained, but the flame stability in the combustion chamber deteriorates
Solution Approach 1:
The control system detects sudden de-loading conditions and activates the blow-off valve in advance to prevent flame instability before it occurs. By opening the valve proactively when de-loading is detected, the system maintains pressure balance and air-fuel ratio, preventing flame blowout rather than reacting after instability occurs.
Solution Approach 2:
The blow-off valve acts as an intermediary component that provides a bypass path for compressed air to flow from the compression stage to the flue gas exhaust stage. This intermediary flow path allows the system to maintain pressure balance and air-fuel ratio during sudden de-loading, stabilizing the flame without requiring direct modification of the combustion chamber.
2Stability of the object's composition
If the blow-off valve opens to stabilize the flame, then the flame stability improves, but the pressure in the compression stage decreases
Solution Approach 1:
The blow-off valve opens partially or fully during sudden de-loading to provide sufficient bypass flow for stabilizing the flame. The control system determines the appropriate valve opening degree based on the severity of de-loading, allowing enough air flow through the bypass to maintain air-fuel ratio and flame stability, while minimizing unnecessary pressure loss in the compression stage.
Solution Approach 2:
The system dynamically changes the blow-off valve opening parameter in response to sudden de-loading conditions. By adjusting the valve opening degree, the control system modifies the bypass flow rate to maintain optimal air-fuel ratio and pressure balance, thereby stabilizing the flame while minimizing pressure loss in the compression stage.
3Device complexity
If no blow-off system is used, then the device complexity is reduced, but the system cannot handle sudden de-loading events
Solution Approach 1:
The blow-off valve assembly serves multiple functions: it stabilizes the flame during sudden de-loading, maintains pressure balance in the compression stage, and controls the air-fuel ratio in the combustion chamber. This multi-functional component allows a single valve assembly to handle various operating conditions and突发事件, justifying its inclusion despite the added complexity.
Solution Approach 2:
The control system continuously monitors operating conditions and provides feedback to the blow-off valve actuator. When sudden de-loading is detected through sensors monitoring pressure, flow rate, or other parameters, the control system automatically adjusts the valve opening to maintain stable operation, enabling the system to adapt to changing conditions dynamically.
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 solution effectively stabilizes the flame in the combustion chamber during sudden de-loading events, preventing damage and ensuring continuous operation by managing the air-fuel ratio and pressure imbalances.
Implementation Method 1
The blow-off valve assembly is configured to provide fluid communication between the compression stage and the flue gas exhaust stage
Data Source
Figure 1
AI summary
For the sake of improving a control system for a gas turbine system having a compressor, a combustion chamber, a flue gas exhaust stage, a driveshaft and a blow-off valve assembly that selectively provides fluid communication between the compressor and the flue gas exhaust stage, the present disclosure teaches a control system comprising a controller configured and adapted to signal the blow-off assembly to provide the fluid communication in response to a sudden de-loading of the gas turbine.