Steam Turbine
Steam Turbines
Table of Contents
Introduction 3
Components 4
Principle of Operation 6
Over-Speed Trip Mechanism 6
Introduction
The Steam Turbine is a device that converts thermal energy to mechanical energy in order to produce work, which is then used to drive a load.
The steam turbine is design based on the Rankin Vapor Cycle shown in Figure 1
Figure 1: Rankin Cycle Diagram
The Rankin Vapor Cycle work in four main processes which are:
Compression – Heating – Expansion – Cooling
Process 1-2: The fluid is compressed in the pump and is transported to the heater / boiler
Process 2-3: The fluid is heated above 100˚C and is converted to high pressure steam
Process 3-4: The steam enters the turbine and causes it to rotate at high speed as the high pressurized steam converts its energy to high velocity and turns the turbine
Process 4-1 the liquid is condensed due to the heat removal in the condenser
Figure 2: Rankin Cycle
Components
The steam turbine consists of the following main components:
Main Stop Valve
Governor Valve
Turbine Casing
Turbine Shaft (Rotor)
Rotor Blades
Stator Blades
Bearings (Thrust & Journal)
Thrust Collar
Seals (Labyrinth)
Trip Mechanism
Table 1: Turbine Compnents
Principle of Operation
High pressure steam is admitted into the turbine through the governor valve which controls the amount of steam entering the turbine. As the steam enters the turbine the guide nozzles directs it to the first set of rotating blades, where its pressure energy is converted into kinetic energy, and forces the turbine shaft to rotate, the steam is then directed to the first set of stator blades where it gains slight increase in potential energy and is then directed to the second set of rotating blades. The process is then repeated until the steam reaches the final stage and then leaves the turbine. The higher the amount of high pressure steam entering the turbine the more velocity the turbine gains.
Figure 3: Simple Steam Plant Cycle
Figure 4: Steam
Table of Contents
Introduction 3
Components 4
Principle of Operation 6
Over-Speed Trip Mechanism 6
Introduction
The Steam Turbine is a device that converts thermal energy to mechanical energy in order to produce work, which is then used to drive a load.
The steam turbine is design based on the Rankin Vapor Cycle shown in Figure 1
Figure 1: Rankin Cycle Diagram
The Rankin Vapor Cycle work in four main processes which are:
Compression – Heating – Expansion – Cooling
Process 1-2: The fluid is compressed in the pump and is transported to the heater / boiler
Process 2-3: The fluid is heated above 100˚C and is converted to high pressure steam
Process 3-4: The steam enters the turbine and causes it to rotate at high speed as the high pressurized steam converts its energy to high velocity and turns the turbine
Process 4-1 the liquid is condensed due to the heat removal in the condenser
Figure 2: Rankin Cycle
Components
The steam turbine consists of the following main components:
Main Stop Valve
Governor Valve
Turbine Casing
Turbine Shaft (Rotor)
Rotor Blades
Stator Blades
Bearings (Thrust & Journal)
Thrust Collar
Seals (Labyrinth)
Trip Mechanism
Table 1: Turbine Compnents
Principle of Operation
High pressure steam is admitted into the turbine through the governor valve which controls the amount of steam entering the turbine. As the steam enters the turbine the guide nozzles directs it to the first set of rotating blades, where its pressure energy is converted into kinetic energy, and forces the turbine shaft to rotate, the steam is then directed to the first set of stator blades where it gains slight increase in potential energy and is then directed to the second set of rotating blades. The process is then repeated until the steam reaches the final stage and then leaves the turbine. The higher the amount of high pressure steam entering the turbine the more velocity the turbine gains.
Figure 3: Simple Steam Plant Cycle
Figure 4: Steam