CERTIFICATE This is to certify that the project work entitled “Different Power Plants“ Is being submitted by Name of the student : Enroll no.: Patel Akshaykumar V Shaikh Shahrukh Tiwari Brijesh Pandey Nitesh For fulfillment of requirements of semester-III of the degree Bachelor of Engineering ELECTRONICS AND COMMUNICATION at GUJARAT TECHNOLOGICAL UNIVERSITY For academic year

 Thermal Power Plants  Steam Power Plants

THERMAL POWER PLANT

 A Thermal Power Plant converts the heat energy of coal into electrical energy. Coal is burnt in a boiler which converts water into steam. The expansion of steam in turbine produces mechanical power which drives the alternator coupled to the turbine.Thermal Power Plants contribute maximum to the generation of Power for any country  Thermal Power Plants constitute 75.43% of the total installed captive and non-captive power generation in India  In thermal generating stations coal, oil, natural gas etc. are employed as primary sources of energy.

 Coal handling plant  Pulverizing plant  Draft fans  Boiler  Ash handling plant  Turbine  Condenser  Cooling towers and ponds  Feed water heater  Economizer  Superheated and Reheated  Air preheated

Coal Handling Plant Coal Handling Plant

Air Fuel HFO,LDO & Coal Boiler Fuel HFO,LDO & Coal Dryer Air compressor FD Fan Atmospheric Air The boiler is fed with HFO and LDO initially to ignite the coal in the Boiler. Types of boilers: 1.Water tube Boiler: A boiler in which water circulates in tubes heated externally by the fire. 2.Fire tube Boiler: Water is present in the drum inside the boiler and Hot air is circulated around maintain the temperature. The fuel and air are feed from 2 directions to increase the efficiency

 The circulation of air is caused by a difference in pressure, known as Draft.  Draft is a differential pressure b/w atmosphere and inside the boiler.  It is necessary to cause the flow of gases through boiler setting  It may be – 1. Natural draft 2. Mechanical draft

The Ash from the boiler is collected in two forms: 1. Bottom Ash(Slurry):It’s a waste which is dumped into a Ash Pond 2. Fly ash: Fly ash is separated from Flue Gases in ESP(Electro static Precipitator). Fly Ash & Flue Gases EconomizerESP Bottom ash(wet ash) Ash Pond Boiler Cylo Cement Factory Economizer : Reduces the temperature Chimney Fly ash Flue Gases

In a Thermal Power Plant generally 3 turbines are used to increase the efficiency.  High Pressure Turbine(HPT): The superheated steam is directly fed to this turbine to rotate it.  Intermediate Pressure Turbine(IPT): The out put from the HPT is reheated in a reheated(RH) and used to rotate IPT.  Low Pressure Turbine(LPT): The Exhausted steam from the IPT is directly fed to rotate the shaft of LPT. Condenser HPTIPTLPT RH Steam Super Heater Generator Steam Shaft *All the turbines are connected to a single shaft which is connected to the Generator.

 Steam after rotating steam turbine comes to condenser. Condenser refers here to the shell and tube heat exchanger (or surface condenser) installed at the outlet of every steam turbine in Thermal power stations of utility companies generally.

o A condenser needs huge quantity of water to condense the steam. o Typically a 2000MW plant needs about 1500MGallon of water. o Most plants use a closed cooling system where warm water coming from condenser is cooled and reused o Small plants use spray ponds and medium and large plants use cooling towers. o Cooling tower is a steel or concrete hyperbolic structure having a reservoir at the base for storage of cooled water o Height of the cooling tower may be 150 m or so and diameter at the

 Advantages of heating water before feeding back to the boiler:- a) Feed water heating improves overall plant efficiency. b) The dissolved oxygen and carbon dioxide which would otherwise cause boiler corrosion are removed in feed water heater c) Thermal stresses due to cold water entering the boiler drum are avoided. d) Quantity of steam produced by the boiler is increased. e) Some other impurities carried by the steam and condensate, due to corrosion of boiler and condenser are precipitated outside the boiler

Water in a Power Plant is used for 1. Production of Steam- for rotating turbine. 2. Cooling Purpose- For cooling of various equipment. Water is recycled and used for various purpose: 3% of water is wasted during this process. Appx 4 cubic mt water is lost /day/MW Raw Water Purified DM water For cooling purpose Steam Conden ser

Reservoir Water Clarification DM Plant (Demineralized Plant) DM Plant (Demineralized Plant) Chlorification & Filtration Chlorification & Filtration Various Equipment Cooling Water Cooling Tower CT Cooling Tower CT Auxiliary cooling Water (ACW) DMCWP DMCW Demineralized cooling Water CWP CT CWP Condenser Boiler Steam water Cool water Hot water Hot Well Dearator 25D  35D 25D  20D PHE Various Equipment D-Degrees CWP-cooling water Pump PHE-Pre heat Exchange Water Cycle

 The coal is brought and crushed to powder. This is feed to Boiler for producing heat  In Boiler the water is converted to steam.  In Super heater the moisture content is removed from the steam and that steam is called super heated steam  The superheated steam rotates the shaft of the High pressure turbine  The Exhausted steam is sent to preheater and the steam then rotates the Intermediate pressure(IP) Turbine  The steam from the IP turbine is then feed to low pressure turbine.  The turbine shaft is connected to the Generator, which produces Electric Power.  The power generated is then Transmitted.

The Synchronous Generator is used to Generate power by connecting the shaft of the Turbine to the shaft of the generator which cuts the magnetic flux producing Emf.  The Generated Voltage will generally 11KV to 20 KV max.  The Generated Voltage is stepped up by connecting Step up transformer and is transmitted and is also used for Auxiliary purposes. Bus Duct Generator Transformer 20KV to 400KV SYNCHRONOUS GENERATOR UAT 20Kv to 6.KV Unit Auxiliary Transformer: This transformer is used to step down the produced voltage and use for Auxiliary purpose.

Steam Power Plant

 mechanical power is produced by a heat engine that transforms thermal energy (from combustion of a fuel) into rotational energy  heat (generated in the furnace) is transmitted to the boiler where water forced into the boiler by the feed pump is converted into steam

 steam drives turbine blades shaft

 the efficiency of a steam turbine is limited by the maximum temperature of the steam produced and is not directly a function of the fuel used (for the same steam conditions, coal, nuclear and gas power plants all have the same theoretical efficiency)

 Operating pressure  Boiler efficiency  Steaming hours  Heating surface  Generating surface  Superheated steam

 Operating pressure – the pressure at which the boiler is operated in service  Boiler efficiency -the ratio between the thermal energy actually absorbed by water and the thermal energy available in fuel (80 – 90 %)

 Steaming hours -the time during which the boiler generates steam  Heating surface -the total surface of all parts exposed to combustion gases (tubes, superheater, economiser)

 Generating surface - a part of the surface in which water is heated and steam is generated (tubes, drum)  Superheated steam = saturated steam + more heat at constant pressure –> dry steam (to avoid damage to tubine blades)

 FURNACE  BOILER  SUPERHEATER  TURBINE  CONDENSER