ROTOR SKIN FOR STEAM TURBINE COOLING
Publication Date: 2012-Dec-31
The IP.com Prior Art Database
The present invention provides a rotor skin for cooling rotors of steam turbines. The rotor skin is provided on the rotor rim to insulate the rotor from the main flow heat conduction. Material used for fabricating the rotor skin may have improved thermal capability. The rotor skin is used in the packing region of the steam turbine. Circumferential discrete axial cooling holes are provided on the rotor through the dovetails. The cooling holes are provided to carry cooling steam along the rotor from the aft direction. The cooling holes are provided for the identified few initial stages for which the rotor is intended to be cooled. Rotor cooling through the rotor skin enables high temperature steam operation and higher power and efficiency in the steam turbines.
The present invention relates generally to wind turbines, and more particularly to measure deflections in or at main shaft of the wind turbines by using optical measuring methods and system.
In general, utility grade wind turbines (i.e., wind turbines designed to provide electrical power to a utility grid) can have large rotors (e.g., 30 or more meters in diameter). The wind loads going through the rotor are not equal at the entire rotor area. Asymmetric loads occur across these rotors due to vertical and horizontal wind shears. As a result, misalignment and turbulence is also caused.
Further, the asymmetric loads contribute to extreme loads, and the quantity of fatigue cycles on the rotor blades and other wind turbine components. Such asymmetric loads causes bending moments on the main shaft and resulting in deflections of the main shaft.
Therefore, there exists a need in the state-of-art to control the loads at rotor blades of the wind turbines.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an exemplary configuration of optical measurement system that is installed in the main shaft of the wind turbine in accordance with the present invention.
The present invention discloses an optical measurement methods and systems to measure deflections in or at main shaft of the wind turbines. The optical measurement systems and methods described herein, comprises a light source like laser, mirror and a detection sensor or receiver.
Figure 1 - Exemplary configuration of optical measurement system.
On one side of the main shaft the light source / laser and the receiver is placed and on the other side of the shaft a mirror is placed. The light feedback that comes from the mirror is detected with a system that measures the deflection, since the deflection of the light is a direct result of the deflection of the main shaft.
The receiver / detection sensor is used to receive the light feedback and transfer it to a voltage or current signal (or on other measurable signal). The produced voltage or current signal (measured deflection of the main shaft) is then transferred to program logic controller (PLC) of the wind t...