What Is Turbine and Principle of Operation ofTurbine Generator?

A turbine is a machine that transforms rotational energy from a fluid this is picked up by way of a rotor machine into usable work or electricity. Turbines attain this either via mechanical gearing or electromagnetic induction to supply strength. Types of generators encompass steam generators, wind turbines, gasoline generators or water turbines. Mechanical uses of turbine power go back to historic Greece. The first wind wheels relied upon gearing and shafts to electricity equipment. Windmills and water wheels are forms of generators too and might power a millstone to grind grain, among other functions.

 

What is Turbine?

 

A turbine is a rotary mechanical device that extracts the potential energy and kinetic energy of fluids and converts them into mechanical energy. It is a prime mover that transforms the energy of working fluid into mechanical energy for the turbine shaft. The shaft is then driven by other mechanisms through reducing gears to get useful work. The basic construction of a turbine has a rotor, which is a shaft or drum with blades attached to it. 

A casing surrounds the rotor, and it contains as well as controls the flow of fluid (turbine like Pelton wheels has no casing for directing the fluid). When the fluid is directed to the rotor by nozzles, due to the shapes of the blades, the fluid imparts momentum or rotational energy to the rotor. The rotational energy of the shaft is then used to do useful work. For example, the turbine is combined with a generator to produce electrical energy in a steam power plant. The turbine has wide application in many fields of industry, transportation, and power generation. It is also used as a prime mover to drive pumps, compressors. The early examples of turbines are windmills, waterwheels, etc. Note that all pressure energy and kinetic energy of fluid gets absorbed by the turbine, large portion of this energy leaves the turbine wheel fluid, leaving the blades. Turbines are designed to increase efficiency and reduce this carryover loss. According to different factors, there are different types of turbines. The turbines are compounded to reduce carryover loss and increase the overall efficiency.

Turbine Generator Operation Principle—Generation of Electricity

 

Most nuclear power plants operate a single-shaft turbine-generator that consists of one multi-stage HP turbine and three parallel multi-stage LP turbines, a main generator, and an exciter.  An HP Turbine is usually a double-flow impulse turbine (or reaction type) with about 10 stages and shrouded blades that produce about 30–40% of the gross power output of the power plant unit. LP turbines are usually double-flow reaction turbines with about 5-8 stages (with shrouded blades and with free-standing blades for the last 3 stages). LP turbines produce approximately 60–70% of the gross power output of the power plant unit. Each turbine rotor is mounted on two bearings, i.e., there are two bearings between each turbine module.

 

These principal steam lines are cross-tied (e.g., by means of steam gatherer pipe) close to the turbine to guarantee that the tension contrast between any of the steam generators doesn't surpass a particular value, in this way keeping up with framework balance and guaranteeing uniform intensity expulsion from the Reactor Coolant Framework (RCS). The steam courses through the primary steam line detachment valves (MSIVs), which are vital, from a security perspective, to the high-strain turbine. Straightforwardly, at the bay of the steam turbine, there are choke stop valves and control valves. 

Turbine control is accomplished by changing these turbine valve openings. In the event of a turbine trip, the steam supply should be disconnected rapidly, ordinarily in a small portion of a second, so the stop valves should work rapidly and dependably.