Steam turbines consist essentially of a casing to which stationary blades are fixed on the inside and a rotor carrying moving blades on the periphery. The rotor is fitted inside the casing with the rows of moving blades penetrating between the rows of fixed blades.
A steam turbine is a machine that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Its modern manifestation was invented by Charles Parsons in 1884.
High pressure casing of a steam turbine is meshed with Hexa mesh to obtain accurate results. 3D casing model is taken up for contact pressure and structural analysis. By carrying out the contact pressure analysis it will be taken care that required contact pressure is maintained at the parting plane and thus no steam leaks out of the
A steam turbine consists of a rotor resting on bearings and enclosed in a cylindrical casing. The rotor is turned by steam impinging against attached vanes or blades on which it exerts a force in the tangential direction.
1. Blade rubs cause bending. Rubbing in the sealing of a high-pressure rotor of a 300-MW unit caused bending of this rotor and blade tip rubs. Courtesy: Ahwaz Power Generation Management
Steam turbines come in many different configurations, including (a) backpressure turbines (BPSTs) operated in cogeneration mode and (b) condensing turbines (CSTs) for power generation. Hybrid configurations, such as (c) extraction turbines and (d) induction turbines, are less common.
The steam turbine is one of the energy converters which converts the pressure energy of steam into mechanical energy in the form of the rotation of the shaft. The modern steam turbine was developed in 1884 by Anglo-Irish engineer Charles Algernon Parsons.
The major components that constitute a steam turbine are: Casing: The Casing should withstand all normal and emergency service loads and allowable piping forces and moments caused by temperature change. The design of turbine casing design shall be such that thermal stresses are minimized.
To show turbine casings acceptable, analysts conduct structural evaluations using finite element analysis (FEA) techniques. This paper outlines the analytical methods used to perform these types of analyses, provides analysis examples, and summarizes the process to create pressure and temperature limit maps.
Turbine Casing MOC. Large casings for low-pressure turbines are of welded plate construction, while smaller L. P. casings are of cast iron, which may be used for temperatures up to 230°C. Casings for intermediate pressures are generally of cast carbon steel able to withstand up to 425°C.