axial shift of a steam turbine is the shifting of turbine rotor in the forward and backward direction due to steam thrust on blades of rotor.
Thrust pads are used to protect the steam turbine rotor from damage due to axial displacement due to axial thrust created by entry of steam in the turbine. generaly the pads clearence is 0.45mm for a bearing size 250mm.
in a radial flow turbine the steam enters the turbine in the direction of its radius and leaves it in the direction of the axis of the shaft. in a axial flow turbine the steam enters the turbine in the direction of the axis of the shaft and leaves the turbine in the same direction.
When steam contains liquid droplets while doing work at high temperatures, the water droplets can etch metal. To combat this, steam can be superheated or the pressure of the system is reduced.
Ljungstrom Turbine is a Radial Outflow Steam Turbine with two counter rotating discs. Blades are mounted in circles one bigger than the other. Blades of one rotor work as nozzles for the other rotor blades. This turbine design is very forgiving on wet steam. It is said that the turbine design had limitations on scaling up above 30 MW and hence could not compete with Axial Flow Turbines.
becouse this steam is use repetdly for the turbine
Axial displacement is the motion along the shaft of the turbine caused by the force exerted by the steam or by the thermal expansion of the shaft and casing.
Thrust pads are used to protect the steam turbine rotor from damage due to axial displacement due to axial thrust created by entry of steam in the turbine. generaly the pads clearence is 0.45mm for a bearing size 250mm.
Sudden change of load Sudden drop of vacuum Sudden drop of Main steam temperature.
The thrust pads will be there at the front or non drive end of the turbine side....These are usually used to limit the axial displacement of the rotor( Means to minimize the movement of rotor axially in order to maintain the axial clearance between the moving blades and the fixed blades of steam turbine rotor).....
in a radial flow turbine the steam enters the turbine in the direction of its radius and leaves it in the direction of the axis of the shaft. in a axial flow turbine the steam enters the turbine in the direction of the axis of the shaft and leaves the turbine in the same direction.
axial shift depends upon the gap between rotot blade and fixed blade , not on float
The TSI system is Turbine Supervisory Instrumentation system, consists of multiple instruments, including speed sensors, speed monitors and so on. The system continuously monitors the steam turbines of all important parameters, such as: rotational speed, overspeed protection, eccentricity, shaft vibration, cover vibration, axial displacement, differential expansion, and thermal expansion. The system helps to improve the availability of steam turbine unit.
it is used balance axial thrust on turbine rotor due to admitting of high pressure steam in to turbine. it basic purpose is to save thrust bearing.
Dummy piston is provided to oppose the axial thrust generated (in the direction of steam) due to incoming steam.
The length of a blade depends on the style (impulse or reaction), the overall size of the turbine, whether it is an axial flow or radial flow turbine, and where the blade is located within turbine of an axial flow turbine. One thing that is constant: the length of the blade increases from the steam or gas inlet to the discharge of the unit. The profile will gradually increase in diameter from inlet to discharge.
When steam contains liquid droplets while doing work at high temperatures, the water droplets can etch metal. To combat this, steam can be superheated or the pressure of the system is reduced.
Lp turbine diaphragm breaks due to positive pressure inside the condenser because of steam expansion.