Turbine Run-Up Control via Condenser Pressure Feedback
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Solution Overview
Problem
Power plant turbines face limitations in startup and operation due to condenser pressure constraints, which restrict their efficiency and flexibility in meeting grid demands, leading to longer startup times, higher fuel consumption, and increased emissions.
Innovation Solution
A control system that receives condenser operating pressure, turbine rotor speed, and last stage blade protection limits to regulate turbine run-up and acceleration, allowing for precise management of rotor speed and speed gradients to avoid critical speed ranges, thereby optimizing turbine operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the turbine is allowed to run up faster to meet grid demands, then productivity and responsiveness improve, but the risk of exceeding condenser pressure limits and damaging last stage blades increases
Solution Approach 1:
The control system dynamically adjusts the turbine run-up rate based on real-time condenser pressure conditions. Instead of using a fixed conservative limit, the system continuously monitors condenser pressure and modulates the governor control signal to optimize the acceleration profile, allowing faster startup when conditions permit while maintaining blade safety margins
Solution Approach 2:
The system implements closed-loop feedback control by continuously monitoring condenser pressure and using this information to adjust the turbine governor control signal. The control system compares actual condenser pressure against target profiles and modifies the run-up rate accordingly, enabling adaptive optimization of startup performance while ensuring blade protection limits are not exceeded
2Reliability
If the turbine operates under stricter condenser pressure limits to protect last stage blades, then reliability improves, but startup time increases and operational flexibility decreases
Solution Approach 1:
The system transitions from static conservative pressure limits to dynamic adaptive limits that evolve during the startup process. The control system adjusts the effective pressure threshold based on the current run-up stage and condenser evacuation rate, allowing the turbine to operate closer to blade protection limits during controlled acceleration phases while maintaining safety margins
Solution Approach 2:
The control system modifies operational parameters during the startup sequence by adjusting the governor control signal to optimize the balance between condenser pressure management and turbine acceleration. This dynamic parameter adjustment enables faster startup times while maintaining blade protection through real-time control optimization
3Productivity
If the turbine run-up is optimized for speed to reduce startup time, then productivity improves, but fuel consumption and emissions may increase due to less efficient operation
Solution Approach 1:
The control system maintains continuous optimization of the turbine run-up process by continuously adjusting the governor control signal based on real-time condenser pressure feedback. This ensures the turbine accelerates as efficiently as possible at each moment, minimizing unnecessary delays and associated fuel consumption while maintaining optimal acceleration profiles
Solution Approach 2:
The system employs periodic adjustments to the governor control signal during the startup sequence, optimizing acceleration in phases rather than using a single fixed rate. This allows the turbine to operate at optimal efficiency points during different stages of startup, reducing overall fuel consumption while maintaining fast startup performance
Data Source
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AI summary
Systems and methods to control power plant operation via control of turbine run-up and acceleration are disclosed. According to one embodiment of the disclosure, a method (800) of controlling a turbine (120) in a power plant (105) can be provided. The method (800) may include receiving (810) an operating pressure of a condenser (140) associated with a power plant (105); receiving (820) a rotor speed of a turbine (120) associated with the power plant (105); receiving (830) a last stage blade (LSB) protection limit (230) for the turbine (120); based at least in part on the operating pressure of the condenser (140), the rotor speed of the turbine (120), and the LSB protection limit (230), allowing (840), via a control system (160), a run-up of the turbine (120). The method (800) may further include: receiving (850) a rotor speed gradient of the turbine (120); receiving (860) one or more critical speed ranges (410, 420) associated with the rotor speed of the turbine (120); and based at least in part on the operating pressure of the condenser (140), the rotor speed, the rotor speed gradient, and the one or more critical speed ranges (410, 420), regulating (870), via the control system (160), at least one of: the rotor speed of the turbine (120) and the rotor speed gradient of the turbine (120).