Thermal-power-plant-training-training-report-aniket-kaushal

Acknowledgment The tree of knowledge grows best when it has sturdy roots and the strength of them is clearly dependent upon our intentions During the journey of knowledge we meet certain people who play a pivotal role in our development and it’s a privilege to thank them for the same So I would take this opportunity in expressing gratitude towards my mentor and guide in this period of vocational training, Mr Summit Chaurasia It would have been extremely difficult to cover this course without his able guidance Then I’m obliged to thank Mr Pawan Tiwari sir who took the pains and interest in explaining the nicks of the thermal power plant I’m ever thank full to my parents and of course god In fact, many people have contributed to this report and I would love to express my gratitude to all of them, like Mr Anil Awasthi, Mr Chandra Prakash, Mr Bharat Patel and many more Aniket Kaushal ANIKET KAUSHAL 0800116012 Abstract A thermal 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 drives an electrical generator After it passes 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 thermal 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 electricity Some thermal power plants also deliver heat energy for industrial purposes, for district heating, or for desalination of water as well as delivering electrical power A large part of human CO2 emissions comes from fossil fueled thermal power plants; efforts to reduce these outputs are various and widespread At present 54.09% or 93918.38 MW (Data Source CEA, as on 31/03/2011) of total electricity production in India is from Coal Based Thermal Power Station A coal based thermal power plant converts the chemical energy of the coal into electrical energy This is achieved by raising the steam in the boilers, expanding it through the turbine and coupling the turbines to the generators which converts mechanical energy into electrical energy ANIKET KAUSHAL 0800116012 Contents PROJECT ……………………………………………………………………………………1 OBJECTIVES…………………………………………………………………………… BRIEF HISTORY/INTRODUCTION OF ORGANIZATION…………………………… ORGANIZATIONAL CHART…………………………………………………………… PLANT LAYOUT………………………………………………………………………… PRODUCTS AND SPECIFICATION………………………………………………………7 PRODUCT FLOW CHART…………………………………………………………………8 CHRONOLOGICAL TRAINING DIARY…………………………………………………11 PRODUCTION PROCESS…………………………………………………………………12 TURBINE……………………………………………………………………………………23 210 MW TURBINES IN PARICCHA………………………………………………………32 MARKETING STRATEGIES………………………………………………………………37 DIVERSIFICATION OR EXPANSION……………………………………………………38 SUGGESTIONS…………………………………………………………………………… 39 CONCLUSION…………………………………………………………………………… 40 REFFERENCES…………………………………………………………………………… 41 ANIKET KAUSHAL 0800116012 Project To study the general concepts and working of thermal power plant, and its components, especially turbine ANIKET KAUSHAL 0800116012 Objectives • • • To learn the basic working of thermal power plants To learn about various components of the same To develop the understanding of the operation and maintenance of turbines ANIKET KAUSHAL 0800116012 Brief history This is a project run under Uttar Pradesh Rajya Vidhyut Utpadan Nigam Ltd UPRVUNL is wholly owned state thermal power utility with present generating capacity of 4082 MW, operating Thermal Power Stations within Uttar Pradesh Poised to contribute in the growth of state, we're in the process of adding further 2000 MW capacity to our existing fleet by year 2012 The name of this power project is paricha thermal power project its foundation war laid in 1979 and it started producing electricity in 1983 It is a state owned semi government project It has four units which are generating electricity Two no of 250MW which are likely to be completed tip to year 2011 Total installed capacity of the plant at present is 640 mw The total installed capacity of the plant will be 1140 mw in the year 2011 presently it is thermal power project of UPRVUNL This project is thermal based power project in which combustion of coal is used to convert water into steam and then steam is used to rotate the turbine the rotation of turbine drives an a.c generator, thereby producing a.c power The entire thermal power project needs continuous supply of water and thus they are built near Betwa river A dam has been constructed for this purpose of collection of water, by the name of paricha dam Coal is also required for this project and it is supplied from mines of BCCL, ECL At present, four units of Parichha are generating 640 mw of electricity Uttar Pradesh Rajya Vidyut Utpadan Nigam Ltd was constituted on 25 August 1980 under the company’s act 1956 for construction of new thermal power projects in the state sector On 14th Jan 2000, in accordance to up state electricity reforms acts 1999, UP state electricity board, till then responsible for generation, transmission and distribution of power within the state of Uttar Pradesh, was unbundled and operations of the state sector thermal power stations was handed over to UPRVUNL ANIKET KAUSHAL 0800116012 PLANT LOCATION IT IS LOCATED IN DISTRICT JHANSI ABOUT 25 KM BEFORE JHANSI, ON KALPIJHANSI ROAD JHANSI IS WELL CONNECTED BY AIR/RAIL AND ROAD ROUTE FROM ALL MAJOR CITIES ABOUT GENERATING UNITS AT PARICHHA THERMAL POWER STATION ALL THE UNITS OF THIS STATION ARE COAL FIRED THERMAL POWER PLANTS, HAVING A TOTAL GENERATING CAPACITY OF 640 MW AND CONSISTS OF FOLLOWING UNITS - STAGE ORIGINAL DERATED ORIGINAL UNITS DATE OF FIRST CAPACITY CAPACITY EQUIPMENTS NO COMMISSIONING MW MW MANUFACTURERS 01 110 110 31.03.1984 BHEL 02 110 110 25.02.1985 BHEL 03 210 210 25.11.2006 BHEL 04 210 210 01.12.2007 BHEL THE COAL TO ALL THESE UNITS IS FED FROM COAL MINES OF BCCL, ECL BY MEANS OF RAILWAYS ANIKET KAUSHAL 0800116012 Organizational chart Chief Engineer, Level Chief Engineer level 2(O&M) Chief Engineer Level 2(admin.) Chief Engineer level (construction) CIRCLE OPERATION AND MAINTENANCE SE SE SE SE SE (CIVIL) SE(HQ) EXECUTIVE ENGINEER EE …… EE EE EE EE(CIVIL) ……… ASSISTANT ENGINEER AE AE AE …… AE AE(CIVIL) JUNIOR ENGINEER JE JE JE … OPERATOR (TG 2) OPERATOR OPERATOR … ANIKET KAUSHAL 0800116012 ……… Plant Layout ANIKET KAUSHAL 0800116012 Products and Specifications Following two are the main products in a thermal power plant:1) Electricity Electricity is produced at approximately 15.5 KV after which it is stepped up to 220 KV for reduction in losses due to transmission Then it is connected to the grid for supply The main client for purchasing electricity of UPRVUNL is UPPCL which is UTTAR PRADESH POWER CORPORATION LIMITED 2) Ash:Ash is the byproduct of coal after its combustion It can be categorized in two parts:1) Fly ash, which is sold to cement manufacturing organizations like Diamond and Satna Earlier they were given away to the same, but since posses certain value, they’re now being sold to them which generates revenues up to twenty lakhs 2) Ash slurry, it is a waste product which is generally provided to construction companies for road-filling etc ANIKET KAUSHAL 0800116012 Impulse turbines An impulse turbine has fixed nozzles that orient the steam flow into high speed jets These jets contain significant kinetic energy, which the rotor blades, shaped like buckets, convert into shaft rotation as the steam jet changes direction A pressure drop occurs across only the stationary blades, with a net increase in steam velocity across the stage As the steam flows through the nozzle its pressure falls from inlet pressure to the exit pressure (atmospheric pressure, or more usually, the condenser vacuum) Due to this higher ratio of expansion of steam in the nozzle the steam leaves the nozzle with a very high velocity The steam leaving the moving blades has a large portion of the maximum velocity of the steam when leaving the nozzle The loss of energy due to this higher exit velocity is commonly called the "carry over velocity" or "leaving loss" Types of turbine blades 27 ANIKET KAUSHAL 0800116012 REATION TURBINES In the reaction turbine, the rotor blades themselves are arranged to form convergent nozzles This type of turbine makes use of the reaction force produced as the steam accelerates through the nozzles formed by the rotor Steam is directed onto the rotor by the fixed vanes of the stator It leaves the stator as a jet that fills the entire circumference of the rotor The steam then changes direction and increases its speed relative to the speed of the blades A pressure drop occurs across both the stator and the rotor, with steam accelerating through the stator and decelerating through the rotor, with no net change in steam velocity across the stage but with a decrease in both pressure and temperature, reflecting the work performed in the driving of the rotor 28 ANIKET KAUSHAL 0800116012 Operation and maintenance When warming up a steam turbine for use, the main steam stop valves (after the boiler) have a bypass line to allow superheated steam to slowly bypass the valve and proceed to heat up the lines in the system along with the steam turbine Also, a turning gear is engaged when there is no steam to the turbine to slowly rotate the turbine to ensure even heating to prevent uneven expansion After first rotating the turbine by the turning gear, allowing time for the rotor to assume a straight plane (no bowing), then the turning gear is ddisengaged isengaged and steam is admitted to the turbine, first to the astern blades then to the ahead blades slowly rotating the turbine at 10 to 15 RPM to slowly warm the turbine A modern steam turbine generator installation Problems with turbines are now rar raree and maintenance requirements are relatively small Any imbalance of the rotor can lead to vibration, which in extreme cases can lead to a blade letting go and punching straight through the casing It is, however, essential that the turbine be turned with dry steam - that is, superheated steam with a minimal liquid water content If water gets into the steam and is blasted onto the blades (moisture carryover), rapid impingement and erosion of the blades can occur leading to imbalance and catastrophic failu failure re Also, water entering the blades will result in the destruction of the thrust bearing for the turbine shaft To prevent this, along with controls and baffles in the boilers to ensure high quality steam, condensate drains are installed in the steam pipingg leading to the turbine Speed regulation The control of a turbine with a governor is essential, as turbines need to be run up slowly, to prevent damage while some applications (such as the generation of alternating current electricity) require precise speed control Uncontrolled acceleration of the turbine rotor can lead to an overspeed trip, which causes the nozzle valves that control the flow of steam to the turbine to close If this fails then the turbine may continue accelerating until it breaks apa apart, rt, often 29 ANIKET KAUSHAL 0800116012 spectacularly Turbines are expensive to make, requiring precision manufacture and special quality materials During normal operation in synchronization with the electricity network, power plants are governed with a five percent droop speed control This means the full load speed is 100% and the no-load speed is 105% This is required for the stable operation of the network without hunting and drop-outs of power plants Normally the changes in speed are minor Adjustments in power output are made by slowly raising the droop curve by increasing the spring pressure on a centrifugal governor Generally this is a basic system requirement for all power plants because the older and newer plants have to be compatible in response to the instantaneous changes in frequency without depending on outside communication 30 ANIKET KAUSHAL 0800116012 31 ANIKET KAUSHAL 0800116012 The 210 MW Turbine of Parichha Thermal Power Project Since I got specially assigned to the turbine department, I had the privilege of understanding turbines more closely Apart from the kind of turbine employed, its specifications, I came across various concepts regarding the steam turbines like axial shift, casing expansion and learnt about the same The turbine used for electricity generation is a three cylinder- reheat- condensing turbine This name means that the turbine assembly is made of three turbines, namely:1) HP turbine (high pressure turbine) 2) IP turbine (intermediate pressure turbine) 3) LP turbine (low pressure turbine) The term reheat is used to imply that the steam, after passing the hp turbine and before entering the ip turbine, is reheated by passing it through the boiler again Since the previous introduction we are well aware of the importance of a turbine and its working in a power plant There are various other aspects like axial shift, casing expansion, bearings, turbine lubrication etc Turbine requires perfect conditions to work efficiently The manufacturer of turbine is BHEL which is abbreviation of BHARAT HEAVY ELECTRICALS LTD The turbine is based on KWU desigh, which stands for KRAFT WORKS UNION The given manufacturer as specified certain condition for turbine working and certain specification of the same, which are as follows 32 ANIKET KAUSHAL 0800116012 TECHNICAL SPECIFICATION OF 210 MW STEAM TURBINE SL.NO DESCRIPTION PARAMETER RATED CAPACITY 210 MW PRESSURE AT STOP VALVE 150 KG/CM2 TEMPERATURE AT STOP VALVE 535 C MAX STEAM FLOW AT S.V 641 TONNES /HR REHEAT/NON REHEAT REHEAT TYPE OF GOVERNING THROTLLE CONTROL TURBINE SPEED 3000 RPM EXHAUST PRESSURE 76 MM HG.ABS NUMBER OF CYLINDERS H.P-1,DOUBLE FLOW IP-1,DOUBLE FLOW LP-1 10 NUMBER OF STAGES HP-25, IP-20 +20,LP8+8 11 HEIGHT OF LAST STAGE BLADE 676 MM 12 LAST STEAGE MEAN DIA 2132 MM 13 SPECIAL FEATURE -DOUBLE SHELL HP WITH BARREL TYPE OUTER SHELL DOUBLE SHELL DOUBLE FLOW IP HYDRAULIC BARRING - ELECTROHYDRAULIC GOVERNING 14 WEIGHT OF TURBINE 425 TONNES 15 LENGTH OF TURBINE 14.1 METERS 16 TYPE OF TURBINE REACTION 17 COLLABORATOR SIEMENS, GERMANY 33 ANIKET KAUSHAL 0800116012 Construction The turbine is a tandem compound machine which separates the hp, ip and lp sections The hp section is single flow while ip & lp are dual flow The turbine rotor and generator rotor are connected by rigid couplings The hp turbine is throttle controlled, the steam is entered ahead of blades via combination of two stop and control valves A swing check valve is installed between the exhaust and the reheater, to prevent the flow of hot steam back into the hp turbine The steam coming from reheater is passed to ip turbine via combination of two reheat stop and control valves Cross around pipes connect the ip and lp cylinders Connections are provided at several point of turbine for feed water extraction HP TURBINE The outer casing of turbine is of barrel type, which has neither axial nor a radial flange This prevents mass concentration which would cause high thermal stresses The inner turbine is axially split, which is accommodate thermal expansion IP TURBINE The ip turbine is a dual flow turbine, with horizontally split casings This is to facilitate thermal movement of inner casing within outer casing LP TURBINE The lp turbine is dual flow It has a three shell design which are horizontally split and are of rigid welded construction The innermost shell, which carries first row of stationary blades, is supported, so as to allow the thermal expansion of inner shell within intermediate shell BLADING The entire turbine provided with reaction blading The moving blades of hp and ip turbine and the blades of front rows of lp trurbine are designed with integrally milled T-roots and shrouds The last stages of lp turpine are fitted with a twisted drop-forged moving blades with firtree roots engaging in corresponding grooves in rotor Highly stressed guide blades of hp and ip parts have inverted T roots and shrouding are machined from one piece like the moving blades The other guide blades have inverted L roots and rivetted shrouding The last three stages of lp turbine have fabricated guide blades BEARINGS The HP rotor is supported on two bearings, a journal bearing on its front end and a combined journal and thrust bearing immediately next to the coupling of the ip rotor 34 ANIKET KAUSHAL 0800116012 The ip and lp rotors have journal bearings at each of their rear ends The combined journal and thrust bearings incorporates a journal bearing and a thrust bearing which takes up residual thrust from both direction The bearing metal temperatures are measured by thermocouples directly under the babbit lining The temperature of the bearing is measured in the two opposite thrust pads on each side SHAFT SEAL ANF BLADE TIP SEALING All shaft seals, which seal the steam from the outer atmosphere are axial flow labyrinth type seals They consists of a large number of thin strips of seals which, in hp and ip turbine are caulked alternately into the grooves in the shafts and the surrounding seal rings In the lp turbine, the seals are caulked only into seal rings Seal strips of similar design are also used to seal the radial blade tip clearences VALVES The hp turbine is fitted with two main stop and control valves One main stop valve and control valve with stems arranged at right angles to each other, are combined in the common body The main stop valves are single seat spring action valves The control valves are also single seat valves but use diffuser a reduce the pressure losses The ip turbine has two reheat stop valves and control valves The reheat stop valves are single seat spring action valve, while the control valves are single seat valves loaded with diffusers The control valves operate in parallel and are completely open in the upper load range The main, reheat and control valves are supported free to move in thermal expansion All the valves are operated by individual hydraulic servomotors TURBINE CONTROL SYSTEM The turbine has an electrohydraulic control system backed up with hydraulic governing system An electric system measures the speed and output and controls them by operating the control valves hydraulically via controller electrohydraulic converter The electro hydraulic controller ensure controlled acceleration of the turbine generator up to the rated speed and prevents the over shooting of speed in case of sudden load rejections The linear power frequency droop characteristics can be adjusted in fine steps even when the turbine is running 35 ANIKET KAUSHAL 0800116012 TURBINE MONITORING SYSTEM In addition to measuring and display instruments for pressure, temperatures, valve lifts and speed etc the monitoring system also includes the instruments for measuring and indicating the following parameters:• • • • • • Absolute expansion measured at the front and rear bearing pedestal of the hp turbine Differential expansion of hp and ip turbines Rotor expansion measured at the rear bearing pedestal of the lp turbine Axial shift measured at the hp-ip pedestal Bearing pedestal vibration, measured at all turbine bearings Shaft vibration measured at all turbine bearings Turbine Stress Controller is provided to monitor thermal stresses in vital turbine components OIL SUPPLY SYSTEM A single oil supply system lubricates and cool the bearings, governs the machine, operates the hydraulic actuators and the safety and the protective devices and the drives the hydraulic timing gear The main oil pump is driven by turbine shaft and draws oil from main oil tank Auxillary oil pumps maintain the oil supply on start-up and shut down, during turning gear operation and when the main oil pump is faulted When the turning is started a jacking oil pump forces high pressure oil under the shaft journals the prevent boundary lubrication The lubricating and cooling oil is passed through oil coolers before entering the bearings AXIAL SHIFT The axial shift is the measure of axial displacement of the shaft within the thrust bearing Axial shift is set at zero when thrust is at the center of the axial clearance at the thrust pads Axial shift towards generator is positive and towards generator is negative Alarm and tripping is provided when the axial shift reading exceeds the set value 36 ANIKET KAUSHAL 0800116012 MARKETTING STRATEGIES The UPRVUNL, is the sister organization of UPPCL, hence all of the electricity generated is sold to UPPCL at a fixed rate which is decided by UP State Electricity Regulatory Authority The other by product, which is fly-ash, is sold to various cement factories like Diamond factory and cement factory of Satna 37 ANIKET KAUSHAL 0800116012 Diversification or Expansion The Parichha thermal power project is in a constant state of expansion in context to the power produced Earlier the plant was of the capacity of 110X2 MW only Its power output was increased to the capacity of 640MW by installation of 210X2 MW units The development is not stopped yet, there is installation 250X2 MW units underway and are expected to be operational with in some time Due to aggressive policy of government in power sector, the power sector is going to show aggressive growth in the coming years 38 ANIKET KAUSHAL 0800116012 Suggestions The plant is working fine with not many hindrances, but the main concern is the cleanliness of plant The plant, especially 110X2 unit building of the plant is not clean enough What I believe is that cleaner environment might help in improving of productivity and decrease the rate of breakdowns This might improve the efficiency of the unit as lesser number of foreign elements will be present which prevent the proper functioning of the unit If the efficiency increases, the coal consumption will be reduced for the same load and that would provide a better profit to the organization 39 ANIKET KAUSHAL 0800116012 Conclusion From all the study it can be concluded that the Pariccha thermal power project of 210X2 unit is a fairly organized unit with the latest machinery available The turbine is a very sophisticated assembly of machinery which requires specific conditions of steam temperature and pressure to work efficiently Any alteration of the specific requirements may prove hazardous to the turbine Another interesting yet worrying fact is the quantity of coal consumed, which approximately 10800 tonne per day The level of pollution is always controlled according the established norms, but still I consider it to be quite enough Well, efforts are always underway inreducing the pollution and improving the efficiency of the plant All in all, a thermal power project is very large establishment with many components and it awes me to see how all the components work in a synchronized manner 40 ANIKET KAUSHAL 0800116012 References • • • • Steam turbine for power generation NPTI Wikipedia indianpowersector.com www.uprvunl.com 41 ANIKET KAUSHAL 0800116012