Report On Steam Power Plant 386761

Report On

Steam Power Plant Introduction: A steam power station is a power plant in which the prime mover is steam driven. Water is heated, turns into steam and spins a steam turbine which either drives an electrical generator or does some other work, like ship propulsion. After it es through the turbine, the steam is condensed in a condenser and recycled to where it was heated; this is known as a Rankine cycle. The greatest variation in the design of steam power stations is due to the different fuel sources. Some prefer to use the term energy center because such facilities convert forms of heat energy into electrical energy.

History The harnessing of steam power ushered in the industrial revolution. It began with Thomas Newcomen (Dartmouth)in the early 1700's. Early developments were very slow and Newcomen's design was used in England for nearly 100years.Newcomen's engine could be better described as a 'vacuum' engine. The vacuum was created by condensing steam. The engine however, was extremely inefficient, and where coal had to be brought from a distance it was expensive to run. James Watt (1769) brought about a major increase in power and efficiency with his developments. Watt redesigned the engine so that condensation occurred outside of the cylinder. This meant that the cylinder did not lose heat during each stroke. It also allowed the use of pressurized boilers thus obtaining power on the upstroke as well as the down stroke. The beam

engine gave way to the reciprocating steam engine which was refined to a high degree. Double and triple expansion steam engines were common and there was scarcely a demand for mechanical energy which steam could not meet. However, reciprocating steam engines were complicated, and hence not always reliable. In 1884 Charles Parsons produced the first steam turbine With Michael Faraday's earlier discovery of electromagnetic induction (1831) the widespread use of electricity had begun. The two technologies came together and with the National grid, progressively eliminated the need for factories to have their own steam plant. Today, mechanical power production using steam is almost wholly confined to electricity generation.

Objectives:    

Know boiler, steam turbine, and Describe cooling towers and condensers. Calculate the power output of a steam turbine power plant.

Description of Steam Power Plant: Basic Steam Plant consists of a: a. Boiler b. Steam Turbine c. Condenser d. Feed pump e. Economizer f. Pre heater

Components used:        

Boiler Heater Inlet valve Pressure check valve Safety valve Steam output nozzle Turbine Inverter

Essentials of Steam Power Plant Equipment: A steam power plant must have following equipment: (a) A furnace to burn the fuel. (b) Boiler or boiler containing water. Heat generated in the furnace is utilized to convert water into steam. c) Main power unit such as a turbine to use the heat energy of steam and perform work. (d) Piping system to convey steam and water.

In addition to the above equipment the plant requires various auxiliaries and accessories depending upon the availability of water, fuel and the service for which the plant is intended. The flow sheet of a thermal power plant consists of the following four main circuits: (a) Feed water and steam flow circuit.

(b) Coal and ash circuit. (c) Air and gas circuit. (d) Cooling water circuit. A steam power plant using steam as working substance works basically on Rankine cycle. Steam is generated in a boiler, expanded in the prime mover and condensed in the condenser and fed into the boiler again. The different types of systems and components used in steam power plant are as follows: (a) High pressure boiler (b) Prime mover (c) Condensers and cooling towers (d) Coal handling system (e) Ash and dust handling system (f) Draught system (g) Feed water purification plant (h) Pumping system (i)Air pre heater, economizer, super heater, feed heaters.

Recommendation: At present, thermal power generation s for approximately 70% of the total amount of electricity produced around the world. However, thermal power generation, which uses fossil fuels, causes more CO2 emissions than other power generation methods. In order to reduce CO2 emissions per unit power produced, Toshiba Group is developing next generation thermal power technologies aimed at improving plant efficiency and commercializing the CO2 capture and storage system. To improve the efficiency of thermal power generation, it is of vital importance that the temperature of the steam or gas used to rotate the turbines is raised. Toshiba Group is working on the development of ultra-high-temperature materials and cooling technologies in order to commercialize an A-USC system (Advanced Ultra-Super Critical steam

turbine system) more efficient than previous models, which is designed to increase steam temperature from 600°C to above the 700°C mark.

Conclusions: Coal fired thermal power plants meet the growing energy demand, and hence special attention must be given to define a strategy for the optimization of these systems. Energy analysis presented for a coal fired thermal power plant has provided information on the irreversibilities of each process. Condenser pressure has little influence on the energy efficiency. However, a reduction in condenser pressure results in an increase of the energy efficiency. With Barapukuria (BM)coal, the energy loss in the combustor was about 35%. In the case of steam generator, the energy loss reduced to 12% from about 18% as the steam parameters were increased from sub-critical to supercritical conditions using this (BM) coal. Due to condenser pressure limitation,the maximum possible overall energy efficiency was found to be about 36.7% with the ultrasupercritical power plant. Decreasing the condenser pressure by 100 mbar will increase the power output by 2.5%.Thus, installing coal-based thermal power plants based on advanced steam parameters in Bangladesh will be a prospective option aiding energy self-sufficiency.

Reference  Google.com  Wikipedia