1.

2. 3.

AMARDEEP.M.JADEJA

B.E. MECHANICAL (THIRD YEAR)

INDUS INSTITUTE OF ENGINEERING & TECCHNOLOGY,AHMEDABAD.

4. CONTENTS

INTRODUCTIONOFBOILER

AIR PREHEATER

ASHHANDLINGPLANT

FUELOILSYSTEM

COALMILL

ID, FD & PAFAN

COOLINGTOWER

FIREFIGHTINGSYSTEM

COALHANDLINGPLANT

TURBINE

SEAWATERSYSTEM

DMPLANT

TDBFP & MDBFPSYSTEM

5. CLASSIFICATION OF POWER PLANTS:

Thermal Power Plant

Diesel Power Plant

Nuclear Power Plant

Hydro Power Plant

Gas turbine Power Plant

Geothermal Power Plant

6. THERMAL POWER PLANT:

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 either drives an electrical generator or does some other work, like ship propulsion. 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

Thermal power stations produce electricity by burning fuel in a boiler to heat water to produce steam. The steam, at tremendous pressure, flows into a turbine, which spins a generator to produce electricity. The steam is cooled, condensed back into water, and returned to the boiler to start the process over.

Power generated by this power plant covers nearly 60% of all power. They work with the help of coal, oil, natural gases, waste heat etc.

7. INTRODUCTIONOFBOILER 8. What is Boiler?

A boiler is defined as "a closed vessel in which water or other liquid is heated, steam or vapor is generated, steam is superheated, or any combination thereof, under pressure or vacuum, for use external to itself, by the direct application of energy from the combustion of fuels, from electricity or nuclear energy."

Boiler INTRODUCTION OF BOILER 9. Boiler According to Indian Boiler Regulations.

IBR Steam Boilersmeans any closed vessel exceeding 22.75 liters in capacity and which is used expressively for generating steam under pressure and includes anymounting or otherfitting attached to such vessel, whichis wholly, or partly under pressure when the steam is shut off.

10. Introduction to Adani Power 660 MW Boiler Description Unit Value Type Supercritical, Once Through Type, Sliding Pressure, Single Furnace, New Tangential Type, Single Reheat, Balanced Draft, Dryed Slag Discharge, Complete Steel Structure, Complete Hanging Construction, Double Gas Passes.Manufacturer HARBIN BOILER COMPANY, CHINA Design Code For Pressure Parts ASME, GB9222-88, IBR 11.

Large Single Funace

7.Low Nox Tangential Burner 6.Burner tiltingfor reheater steamtemperature control 3.Proven and economic heatingsurface arrangement 2.Spirally wounded evaporators for safe and reliableevaporator 5.Economic and safe low load andstartupsystem by circulating pump 8.Long life and highPerformance mills 4.High Strength materialapplication Overall View Of Adani Boiler 12. CRITICAL CONDITION

Definition

CRITICAL is a thermodynamic expressiondescribing the state of a substance beyond which there is no clear distinction between the liquid and gaseous phase.

The critical pressure & temperature for water are

Pressure = 225.56 Kg / cm2

Temperature = 374.15 C

13. SUPER CRITICALBOILER CYCLE WITH SH, RH & RegenerationofADANI5 x 660MW 256Kg/cm2 0 100 200 300 400 500 600 540C 568C Steam flow:2225 T/Hr Steam temp: 540 c Steam Pres : 256 kg/cm2 RH pre: 51.6 Kg/cm2 RH Temp: 568c Feed water Temp: 291c ENTROPY TEMP 14. WHY SUPERCRITICAL PRESSURE

The purpose of having high inlet steam pressure for turbine can be inferred from Previous deliberations.

A Boiler operating at a pressure above critical point is called SUPERCRITICAL BOILER

A point where boiling water and dry saturated lines meet so that associated latent heat is zero, this point is called Critical Point and occurs at 225 kg/cm2 (abs) 374.15 C temperature.

15. SH DRUM ECO HTR BFP W/WALL DOWN COMER RISERS Natural Circulation BoilerW/WALL BFP HTR ECO SH SEPERATOR ONCE THROUGH SYSTEM 16. FLOW DIAGRAM OF SIPAT SUPER-CRITICAL BOILER 17. Evaporator Wall Construction (1/3)

Upper Part

Vertical Wall

Lower Part

Spiral Wall

18. Spiral wall outlet temp at BMCR (front wall) Spiral Wall Evaporator Configuration of Evaporator panel Spiral wall : Vertical wall = 3 : 1 Supercritical Boiler Technology 19. spiral wall spiral wall and windbox WALLOFBOILER 20. 660 MW PLANT BOILER 21. LTSH COILS ECONOMISER COILS ECONOMISER I/L HEADER ECONOMISERO/L HEADER 22. AIR PREHEATER 23.

The Air Preheater absorbs waste heat from flue gas, and then transfers this heat to incoming cold air by means of continuously rotating heat transfer elements of specially formed metal plates.

Air Preheater is in general divided into two types:

• Regenerative

• 2. Recuperative

24.

1) Regenerative APHare also known as storage type heat exchangers, have an energy storage medium, called the matrix, which is alternately exposed to the hot and cold fluids. When the hot flue gases flow through the matrix in the first half of the cycle, the matrix is heated and the gas is cooled. In the next half of the cycle when air flows through the matrix, air gets heated and the matrix is cooled. The cycle repeats itself.

25.

2) Recuperative APH,heat is directly transferred from the hot gases to the air across the heat exchanging surface. They are commonly tubular, although some plate types are still in use. Tubular units are essentially counter-flow shell-and-tube heat exchangers in which the hot gases flow inside the vertical straight tubes and air flows outside. Baffles are provided to maximize air contact with the hot tubes.

26. Regenerative Type Air Pre Heater

Nos. 2

Speed of Rotation 0.9rpm

Cooling water Consumption 18t/h

Air temperature at Regenerative APH outlet -

27. General Arrangement of Airpreheater

SA

SA PA FG FG PA TG HouseChimney 28. Air Preheater, main technical specifications and list of master drawings 29.

• List of master drawing

1General arrangement of Air Preheater.

2.Rotor assembly

3.Rotor radial seal assembly

4.Rotor module assembly.

5.Rotor post and trunnion assembly.

6.Hot end and hot intermediate layer elements and element baskets.

7.Cold end element and element basket.

8.Rotor housing assembly.

9.Hot end primary center section assembly.

10. Cold end primary center section assembly.

11. Hot end connecting plate assembly.

12. Cold end connecting plate assembly.

13. Guide bearing assembly.

14. Support bearing assembly.

15. Static seal assembly (hot end and cold end).

16. Axial and by-pass seal assembly.

17. Rotor drive assembly.

18. Sector plate assembly (hot end and cold end).

19. Air seal pipe, observation port and vapor or dust proof light assembly.

20. Stationary water washing device (hot end and cold end) and fire fighting device

21. Special tools and spare parts.

30. Isometric view of Air Preheater 31. AIR PRE-HEATER OPERATION

PRE START CHECKS

Support bearing/ guide bearing lubricating oil pumps RUNNING and lubricating oil coolers are CHARGED.

Bearing temperature NOT HIGH (less than 60oC)

Electrical supply to APH motor is AVAILABLE.

Local operation - Isolating valves of air motors are 'OPEN' and bypass valves of air motor solenoids are 'CLOSED'.

'Air motors' lubricating oil level ADEQUATE

Service air pressure is ADEQUATE (> 5 Kg/cm2)

32.

APH STARTING PROCEDURE

WHEN BOTH APHS ARE OFF

START air motor of APH.

Air motors ON indications come on

Isolating dampers of APHs start opening.

INSTRUCT local operator to check, locally for any abnormal sounds from bearings/seals.

START air heater electrical motor.

Breaker CLOSED & its indication comes onUCB

Associated air motor stops.

Starting current shoots up and comes down to normal load current.

AIR PRE-HEATER OPERATION 33. AIR PRE-HEATER OPERATION

Isolating dampers of the air heater remain open.

Isolating dampers of the other air heater, not in service, start closing if its air motor is not ON.

INSTRUCT local operator to check, locally for any abnormal sounds from bearings/seals.

There should be no abnormal hunting in air heater amperes meter readings.

There should be no abnormal sounds from air pre-heater seals or bearings.

Bearing temperatures must be within the normal range (650 C -750 C)

34. Parameters related to APH

Make : Ljungstorm

Type : Trisector

Oil used : TC 680 cyndol (Bearing)

EP 320 Parthan (Gear Box)

Motor Drive :

Main Motor (Electric driven, AC)

Stand by motor (Electric driven, AC)

Motor: N=970rpm , Speed Reducer Assembly O/P: N=0.89 rpm

35. 36. ASHHANDLINGPLANT 37. INTRODUCTION

Ash is a waste product of coal and solid fuel combustion. It contains many harmful elements which can contaminate sub-soil water of water is allowed to seep through ash into soil. Further, percentage of ash present in Indian coals is large. As a result, disposal of ash also uses up considerable area of land, which could otherwise be put to better use.

Therefore, it is desirable to put ash to use so that the problem of providing land area for its disposal is solved. All out efforts are being made for finding uses of ash. Presently, only negligible amount of total ash produced in the country is put to use. However, ash being a good landfill material can be used in bulk in projects like highway construction. This is being done to as large an extent as possible.

Pollution Control Regulations have made it mandatory to dispose ash in dry form only so that harmful elements do not find ingress in the sub-soil water

38. ASH HANDLINGSYSTEM

In modern boilers ash is collected in two locations namely (i) Bottom of the furnace and (ii) in Electrostatic Precipitators (or Dust Collection Systems). Out of these two fractions generally the quantity of ash collected in Electrostatic Precipitators (or Dust Collection Systems) is larger. Ash collected in the Bottom of Furnace is generally small in quantity and is handled wet, whereas that collected in Electrostatic Precipitators (or Dust Collection Systems) is now collected by means of dry handling systems.

39. Silos for collection of FLY-ASH 40. FLY ASH HANDLING SYSTEM

The fly ash handling plant will remove fly ash from Electro static precipitator (ESP) hoppers and transport it to the storage silos. This will be carried out by pressure pneumatic conveying system on a continuous, cyclic basis. One boiler unit will be provided with one pneumatic conveying system for handling fly ash collected in the ESP hopper. The system layout and the conveying pipeline configuration will be designed and constructed to enable evacuation of fly ash at maximum design rate. The output of the system will be not less than 200% of actual ash amount. The capacity of each set of system will be 30t/h.

41. ELECTROSTATIC PRECIPATATOR

It is a device which captures the dust particles from the flue gas thereby reducing the chimney emission.

Precipitators function by electrostatically charging the dust particles in the gas stream. The charged particles are then attracted to and deposited on plates or other collection devices. When enough dust has accumulated, the collectors are shaken to dislodge the dust, causing it to fall with the force of gravity to hoppers below. The dust is then removed by a conveyor system for disposal or recycling 42. LOCATION OF ESP ESP CHIMNEY APH ECO 43. Electro Static Precipitator

Basic Principle

44. ESP PROCESS STEPS Collectingelectrode, grounded Rapping mechanism Discharge electrode with Negative high tension (20-60kV) 4.dust collection 4 Dust layer 1 1.Electron emission 2 2.Dust particle charging 3 3.Migration 5 5.Rapping 45. ESP Flue gas Emitter coil Gas distribution plate Collector plate 46. ESP TECHNICAL SPECIFICATIONS Description Unit Value Nos. of Gas Stream / ESP Double Nos. of Parallel Path per Stream Nos. 38 Nos. of electrical fields in series Nos. 5 Total active treatment length per stream m 3.5 Treatment Time Seconds 15 47. Description Unit Value Total Number of Electrode Nos. 3192 x 2 Total numbers of Rappers per Unit Nos. 7 Total Nos. of Transformer Rectifier Unit Nos. 20 Capacity of Transformer Rectifier Unit Each KVA 1.6A/72 KV Total No. of Dust Hoppers Nos. 40 48. FUEL OIL SYSTEM 49.

There are two types of fuels are used for ignition in combustion chamber.

1) Heavy fuel oil(HFO).

2) Light diesel oil(LDO).

50. HEAVYFUELOIL

The density of HFO is higher.

Cost is low compare to the LDO.

The viscosity is high.

The auxilary steam is mixed for easely flowing through pipe.

The storage tank of HFO is 2000 m3

51. BOILER LIGHT-UP

"HFO" inlet and re-circulation flow start increasing

"HFO header pressure very low" alarms clear off.

HFO temperature in the HFO header increases up to 110o C.

OPEN Ignitor oil trip valve

Ignitor oil trip valve opens up.

Ignitor air fans A & B, start automatically.

Ignitor oil and ignitor air pressure increase up to 23 Kg/cm2 and 400 mm wcl, respectively.

"Ignitor air to furnace DP low & "Ignitor oil/Atomising air pressure low" & "Ignitor oil/HFO trip valve closed" alarms clear off.

CHECK these parameters are within their operation limits.

Drum level normal (-60 mm. to 0, preferably on lower side).

52. BOILER LIGHT-UP

HFO temp. 110o C . (Min. temp. required is 95o C).

HFO atomising steam pressure 8.75 Kg/cm2

Light oil pressure more than 15 Kg/cm2.

Ignitor atomising air pressure 5 to 7 Kg/cm2

Wind box pressure between 35 to 40 mm wcl

ADJUST HFO header pressure set point to 50%(13 Kg/cm2) and TRANSFER its control to auto.

HFO pressure controller transfers to auto and modulates to maintain the set HFO header pressure.

CLOSE heavy fuel oil re-circulation valve.

HFO re-circulation flow valve closes.

HFO re-circulation flow comes to minimum position

53. 54. LIGHTDIESELOIL

The density of LDO is low.

Cost is high compare to the HFO.

The viscosity is low.

The fuel is easely flowing through pipe.

The storage tank of LDO is 300 m3

55. 56. 57. COAL MILL 58. INTODUCTION

As coal powder is the most important fuel in the power plant, the plant owners need coal mill or coal pulverizer to grind the coal to micro powders. Raw coal (crushed) is fed through hopper at the top of the coal pulverizer and falls down to grinder ring to be pressed, crushed and milled into pieces by rollers. After the first crush, coal powder fall into the second and third layer. The pumping of the high-pressure centrifugal blower put the outside air into the coal mill. The coarse coal powder will be brought into the classifier.

59. TYPES OF MILLS

1) Ball mill

2) BallandRace mill

3) Impact or Hammer mill

4) Bowl mill

60. COALMILL 61. A B C D E F ESPPASS A ID-A ID-B PA-B FD-B PA-A FD-A FURNACE WIND BOX SCAPH SA PA FG SA PA FG SCAPH ESPPASS B ESPPASS C ESPPASS D WIND BOX ESP I/L X OVER DUCT ESP O/L X OVER DUCT SA X-OVER DUCT COLD PA HOT PA FLUE GAS COLD SA HOT SA CHIMNEY MILL LOCATION APH APH MILL 27C 324C 320C 1165C ECO I/L 493C 351C 136C 134C 129C 126C 62. Milling System

PRE START CHECKS(Typical: Raymond Bowl Mill)Local

Ensure R.C. Bunker level satisfactory.

R.C. feeder and mill properly boxed up and no maintenance staff working.

Gear box oil level normal.lubricatingoil coolers charged.

Pulveriser START PERMIT is AVAILABLE. (Boiler total airflow is < 40% and all burners are HORIZONTAL). Alternatively, if anyone coal feeder is proven then start permit will come from the proven feeder.

Tramp iron gate open.

Cold air gate 100 % open. Hot air gate closed.

Mill outlet valve open.

Seal air valve 100 % open.

"No unsuccessful start" permissive for pulveriser is ON.

Mill fire fighting system ready.

63. Milling System

PRE START CHECKS(Typical: Raymond Bowl Mill)UCB

Ensure no PTW pending.

Ensure at least one P.A. fan and a seal air fan is in service. Check the header pressure for both primary and seal air is normal.

Check that mill ignition energy is O.K. (Minimum 3 out of 4 gun nozzle valves in adjacent elevation are open and elevation oil flow is more than 30% OR adjacent feeder speed is more than 50% and boiler load is more than 30%.

Check that mill start permissive as per FSSS are satisfied

Ensure E.P. zones have been charged (for first mill).

Get the electrical supply for the mill.

Inform the local operator to be near mill for start up.

Start the mill

64. Milling System

POST START CHECKS

Local-Check there is no abnormal sound from mill. Check return oil flow from upper bearing is satisfactory. Check all the rollers are rotating and the rate of reject is normal (after the mill is loaded).

U.C.B. -Check mill starting time and current. Ensure that they are normal. Open hot air gate. Warm up the mill.

Start the RC feeder and load the mill gradually.

Keep the air flow through mill - 54 T/hr.

Keep watch on mill differential to avoid mill choking.

Maintain mill outlet temperature between 75C to 80C.

As the pressure, temperature of main steam shoots up with coal firing proper check should be kept on these parameters. (Especially for first mill).

65. Milling System

MILL SHUTDOWN PROCEDURE

TRANSFER mill feeder and fuel master controller to manual.

Fuel master and feeder control transfer to manual.

REDUCE feeder speed to minimum, gradually.

Coal flow to mill starts coming down.

Other running feeders start loading up, to maintain boiler loading, if on auto.

STOP the mill feeder.

Hot air gate closes with a time delay of 30 sec approx.

Mill current and differential pressure start reducing as the mill becomes empty, gradually.

EVACUATE the mill reject chamber locally and STOP the mill.

Mill temperature comes down to less than 50 0 C.

Mill CAD goes to