Ppt Steam
STEAM TURBINES
A steam turbine is a prime mover which converts heat energy into mechanical energy. In a conventional steam turbines cycle, water is used as the working fluid. The water is heated in a boiler by burning fuel. It evaporates into steam which is expanded in a turbine where mechanical power is generated. The steam generated is of high temperature and high pressure. The temperature is often in the 450 to 540 degrees centigrade range. The pressure ranges between 60 and 120 bar. The essential parts of all steam turbines are similar, consisting of nozzles through which steam flows and expands (dropping in temperature and gaining kinetic energy) and the blades against which the swiftly moving steam exerts pressure. The blades are mounted on rotor drum, and an outer casing confines the steam to the turbine. Both temperature and pressure fall as the steam passes through the turbine. The greater the pressure drop, the more energy can be captured from the steam. The more efficient power plants condense the steam back to water at the end of the turbine. The theoretical maximum efficiency of a steam turbine- based power plant is determined by the difference between the temperature at which steam enters the high pressure turbine and the temperature at which it exits the low pressure turbine. The greater the temperature difference, the more energy can be extracted. Steam turbines are finding greater use in process industries (like steel and chemicals) producing large quantities of waste heat. The waste heat produced can be used to generate steam as well as power. The capital cost of such plants can be slightly higher but the generation of power represents a useful by-product when the waste must be burnt in any case. Steam turbines can also be deployed advantageously in industries with greater requirements of both steam and power. They are used in cogeneration or combined heat and power applications where process steam is also used in the turbine to
A steam turbine is a prime mover which converts heat energy into mechanical energy. In a conventional steam turbines cycle, water is used as the working fluid. The water is heated in a boiler by burning fuel. It evaporates into steam which is expanded in a turbine where mechanical power is generated. The steam generated is of high temperature and high pressure. The temperature is often in the 450 to 540 degrees centigrade range. The pressure ranges between 60 and 120 bar. The essential parts of all steam turbines are similar, consisting of nozzles through which steam flows and expands (dropping in temperature and gaining kinetic energy) and the blades against which the swiftly moving steam exerts pressure. The blades are mounted on rotor drum, and an outer casing confines the steam to the turbine. Both temperature and pressure fall as the steam passes through the turbine. The greater the pressure drop, the more energy can be captured from the steam. The more efficient power plants condense the steam back to water at the end of the turbine. The theoretical maximum efficiency of a steam turbine- based power plant is determined by the difference between the temperature at which steam enters the high pressure turbine and the temperature at which it exits the low pressure turbine. The greater the temperature difference, the more energy can be extracted. Steam turbines are finding greater use in process industries (like steel and chemicals) producing large quantities of waste heat. The waste heat produced can be used to generate steam as well as power. The capital cost of such plants can be slightly higher but the generation of power represents a useful by-product when the waste must be burnt in any case. Steam turbines can also be deployed advantageously in industries with greater requirements of both steam and power. They are used in cogeneration or combined heat and power applications where process steam is also used in the turbine to