Difference between velocity compounding turbine and pressure. This method of compounding is used in rateau and zoelly turbines. Compounding of steam turbines is the strategy in which energy from the steam is extracted in a. In all turbines the rotating blade velocity is proportional to the steam velocity passing over the blade. The first practical electricity generating system using a steam turbine was designed and made by charles parsons in 1884 and used for lighting an.
Are you a person willing to work in industrial sectors then logon to steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Steam turbine convert a part of the energy of the steam evidenced by high. The reaction principle, the impulse turbine, compounding of impulse turbine. Pressure compounding is the method in which pressure in a steam turbine is made to drop in a number of stages rather than in a single nozzle. As the steam emerges in a jet from between the rotor blades, it creates a reactive force on the blades which in turn creates the turning moment on the turbine rotor, just as in heros steam engine. Highpressure turbine an overview sciencedirect topics. In steam turbine compounding there are three major forms of. Pressure compounding velocity compounding pressure velocity compounding. Therefore, for good efficiency the blade velocity should be about one. If the steam is expanded only in a single stage from the boiler pressure to the exhaust pressure, its velocity must be extremely high. Steam turbine compounding of steam turbine mechanicaltutorial. In order for the steam to give up all its kinetic energy to the moving blades in an impulse turbine, it should leave the blades at zero absolute velocity. So, steam s pressure drop and it will increase its velocity.
Principles of operation of a steam turbinewhen high temperature steam passes through a steam turbine. Newtons third law for every action there is an equal and opposite reaction. Impulse turbines, reaction turbines, the impulse principle, the reaction principle, the impulse turbine, compounding of. Compounding of steam turbines is the strategy in which energy from the steam is extracted in a number of stages rather than a single stage in a turbine. Compounding of steam turbine free download as powerpoint presentation. There are two types of modern steam turbines impulse turbine in this type of turbine the steam nozzles direct superheated steam at the buckets of rotor blades, the impact of this causes the rotor to rotate. This condition will exist if the blade velocity is equal to one half of the steam velocity. Velocity compounding an impulse turbine that is velocity compounded has fixed and moving blades. Cross compound steam turbine arrangement for marine use. Excellent text on steam turbine design but now dated as it covers only smaller units. This type of compounding is known as the pressure compounding and the nozzle and blade arrangement for a pressure compounded impulse turbine is sketched. The several sets of blades in a single turbine are perhaps better thought of as similar in principle to the uniflow steam engine than to compounding. Figure 4 shows steam process in enthalpy against entropy diagram of curtis and single row rateau turbine.
In this type, the total pressure drop of the steam does not take place in the first nozzle ring, but is divided up between all the nozzle rings. The following are chief methods for reducing the rotor speed. In principle, the impulse steam turbine consists of a casing containing stationary steam nozzles and a rotor with moving or rotating buckets. Lecture series on steam and gas power systems by prof. What is velocity and pressure compounding in impulse turbine. Steam is expanded in nozzles as well as it passes through blades. Normally the high pressure and intermediate pressure stages of a steam turbine are of the impulse type. It includes heat exchange and energy conversion equipment.
Steam process in steam turbine steam entrance to turbine through governor valv e to control steam capacity and therefore to control turbine speed. In its simplest form, a steam turbine consist of a boiler steam generator, turbine, condenser, feed pump and a variety of auxiliary devices. In general, a steam turbine is a rotary heat engine that converts thermal energy contained in the steam to mechanical energy or to electrical energy. Compounding of steam turbine in hindi by d verma sir. The rotor arrangement can be either tandemcompound. Steam for turbine is provided by pp330140p55 type steam generator, a oncethrough coalfired boiler 8. This refers to the use of blading which causes a series of pressure drops and a series of velocity. Steam pressure at the outlet side of blade may be less than that at inlet side. The steam turbines operate at very high speed in the range 30000 r. Impulse turbine and reaction turbineprinciple, working and. The method in which energy from steam is extracted in more than single stage is called compounding. Steam turbine is device where kinetic energy heat converted into mechanical energy in shape of rotation. In modern steam engine practice high pressure steam is used, as the use of such a. The steam is partially expanded in the highpressure casing, then exhausted to the lowpressure casing.
This provides a follow up of basic engineering cycles with applications to conventional power plants. The devices as a load operate at slow speeds in range of to 4000 r. Schematic diagram of 200 mw unit 8 construction of the steam generator is carried out in two distinct bodies, symmetrical with the axis of the group, operating in parallel to the k2001 steam turbine. Development of tandemcompound 1,000mw steam turbine and. Pressure compounding of an impulse turbine is the use of a number of stages of nozzle and blade to reduce progressively the steam pressure. According to the blade and wheels arrangement, it may be divided following categories. The first recorded example of a steam turbine was heros aeolipile, a reaction turbine dating from about 60 a. In case of turbines with cooling water preheating and lowpressure lp bypass, prior to supplying steam the regeneration and dumping systems have to be. Steam pressure at the outlet side of blades equals that at inlet side. Compounding of steam turbines what is nuclear power. Compounding and governing of steam turbines with methods. This highvelocity strikes the turbines rotor and the speed of the rotor. The hp turbine is a pressurevelocity compounded, single axial flow, noncondensing impulse turbine.
Steam pressure inside the turbine is literally equal to the atmospheric pressure so there will be no problem of steam leakage. Aug 19, 20 a condenser installed at the exhaust or low pressure end of the turbine receives and condenses the steam prior to it being pumped back to the boiler. A pressurecompounded impulse stage is a row of fixed nozzles followed by a row of moving blades, with multiple stages for compounding. Cross compound steam turbine arrangement compounding is the splitting up, into two or more stages, of the steam pressure or velocity change through a turbine.
In this article we will discuss about the methods of compounding and governing of steam turbines. Compounding of steam turbines is the method in which energy from the steam is extracted in a number of stages rather than a single stage in a turbine. Steam turbines their construction, selection and operation pdf. Steam is coming from nozzles when passed through a single set of moving blades called single stage steam turbine and to flow multistages of moving blades called multistages steam turbine. Thermal engineering pdf of rk rajput for mechanical. Unlike the uniflow steam engine, which has found niche uses only, multiple row turbines have found enormous practical application. This highvelocity strikes the turbines rotor and the speed of the rotor becomes high.
Steam expands from boiler pressure to the condenser in one stage. Feb 19, 2017 lecture series on steam and gas power systems by prof. Reaction turbine this type of turbine the rotor blades act as nozzles, steam. Impulse turbines, reaction turbines, the impulse principle, the reaction principle, the impulse turbine, compounding of impulse turbine. As the steam turbine spins the generator spins and creates electricity. Pdf power plant lecture notes chapter4 steam turbine. Prior to supplying steam to the turbine, the steam supply pipelines have to be drained and heated up. The chance of steam leakage will be more when compared to velocity compounded turbine. It is the process by which rotor speed come to its desired value. The motive power in a steam turbine is obtained by the rate of change in.
Pdf compounding of steam turbine lecture slide 04 md. Pressurevelocity describes the type of compounding. Compounding of steam turbine mechanics rotating machines. Steam turbine working principle and types of steam turbine.
The steam is fed through one or several nozzles which do not extended completely. What is pressure compounding rateau turbine zoelly. Compounding is a method of absorbing the jet velocity in stages when the steam flows over moving. The modern power plant concept is based on multiple turbine cylinders with the rotors coupled to a single shaft.
Two types of modern steam turbines and their mechanical. Pdf power plant lecture notes chapter2 steam power plant. Following figures show steam process in steam turbine. What is steam turbine description and characteristics. Proceedings of the south african sugar technologists association. Definition a steam turbine is a prime mover in which the potential energy of the steam is transformed into kinetic energy and later in its turn is transformed into the mechanical energy of rotation of the turbine shaft. Compounding of steam turbine is used to reduce the rotor speed.
In this arrangement, the pressure of the steam drops in each set of nozzles as indicated by the pressure graph. Compounding of steam turbines is the method in which energy from the steam is. A compound turbine is a steam turbine in which there are two casings, a high pressure casing and a lowpressure casing, operating in concert to extract work from a single source of steam. It is designed to efficiently extract work out of high pressure steam. In steam turbine compounding, there are three major forms of compounding turbines which include the velocity compounding, pressure compounding, and pressurevelocity compounding. Power plant lecture notes chapter2 steam power plant cycles.
When the steam passes through the stationary nozzles and is directed at high velocity against the rotor buckets. In order for the steam to give up all its kinetic energy to the moving blades in an impulse turbine, it should leave the. To improve the thermal efficiency of any power plant, generally high pressure near about 120 to 140 bar, high temperature and highvelocity steam is used. Applications of steam turbines power generation transport 4. Schofield ge company schenectady, ny introduction the need to provide stateoftheart products for a diverse and everchanging market is the chal lenge facing steam turbinegenerator manufactur ers in the 90s.
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