Steam Turbine Coupling with Differential Angle Control
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Solution Overview
Problem
In combined gas and steam power plants, the random coupling angle between gas and steam turbines leads to unoptimized vibration loads, as existing methods do not effectively minimize imbalances and vibration loads during the coupling process.
Innovation Solution
A method where the steam turbine is accelerated to match the gas turbine's speed, with a differential angle adjustment to achieve an optimal coupling angle, allowing for continuous acceleration without interrupting the process, enabling quick engagement and minimizing vibration loads by controlling the clutch angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the steam turbine is accelerated to match the gas turbine speed with differential angle adjustment, then the coupling angle is optimized to minimize vibration loads, but the control complexity and measurement requirements increase
Solution Approach 1:
The system performs preliminary measurement of the differential angle between the two turbines before coupling, and pre-calculates the required acceleration profile to achieve the target coupling angle. This allows the control system to plan the entire coupling sequence in advance, optimizing vibration characteristics while maintaining manageable control complexity through systematic pre-computation.
Solution Approach 2:
The invention implements dynamic acceleration control where the steam turbine's acceleration is continuously adjusted based on real-time differential angle measurements and speed differences. The acceleration profile is not fixed but adapts dynamically during the coupling process, allowing optimal vibration minimization while maintaining system stability through feedback control.
2Productivity
If continuous acceleration is used without interruption, then the coupling process is quick and efficient, but precision in achieving the target coupling angle becomes more difficult
Solution Approach 1:
The system continuously measures the differential angle and speed difference during acceleration and uses this feedback to adjust the acceleration profile in real-time. This closed-loop control enables the steam turbine to reach the target coupling angle with high precision even during continuous acceleration, reconciling the need for speed with the requirement for angular precision.
Solution Approach 2:
The invention dynamically changes acceleration parameters based on the current state of the system. By adjusting the acceleration rate as a function of the differential angle and speed difference, the system maintains precision throughout the continuous acceleration process, achieving both high coupling speed and accurate angle control.
3Reliability
If the steam turbine is accelerated below gas turbine speed initially, then sufficient steam availability is ensured, but the coupling process takes longer
Solution Approach 1:
The system maintains continuous acceleration of the steam turbine from its initial lower speed through the coupling process, without interrupting or holding at intermediate speeds. This continuous acceleration minimizes the time required to reach coupling speed while ensuring that the turbine starts from a speed that guarantees sufficient steam availability, thus resolving the time-reliability trade-off.
Data Source
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AI summary
The invention relates to a method for coupling a rotational device, particularly a steam turbine, and a shaft device, particularly a gas turbine, said method comprising the following steps: accelerating the rotational device up to an output rotational speed that is below the rotational speed of the shaft device; detecting a differential angle between the shaft device and the rotational device; and accelerating the rotational device with an acceleration value that is derived from the target rotational speed difference, which is formed as a function of the detected differential angle, the acceleration and a desired target coupling angle. The invention also relates to an associated arrangement.