BRIEF HISTORY OF PLANT

Ever widening gap between the power demand and its

availability in the state of Punjab was one of the basic

reasons for envisaging the thermal plant at “Lehra

Mohabbat” Distt. Bathinda. The other factors favoring the

installation of this thermal were low initial cost and less

generation period as compared to hydroelectric

generating stations, its good railway connection for fast

proximity to load center. Guru Gobind Singh thermal plant

is Government undertaking (under P.S.E.B.)

Initially it was going to set up at

Bathinda under GNDTP but the air force personal

restricted its set up at Bathinda hence plant site is shifted

to Lehra Mohabbat about 22Km from Bathinda city. Later

this plant was approved as a separate autonomous body

with its name as Guru Hargobind Thermal Plant.

The construction of the plant

commenced in 1992 and its unit started working in

December 1997. Its second unit commenced in August

1998. The main companies whose technology pawed the

way of this plant are TATA Honeywell & BHEL in turbine

and boiler control .The total set up cost of the plant is

1200 crores and the capacity of the plant is 2*210 =420

MW. The over all efficiency of the plant is 95%.

1

The power availability from the plant now

meets 20-25% of the total power requirement in Punjab. It

has gone a long way in ushering prosperity in the state by

emerging a large number of agricultural pumping sets,

more industrial connections, 100% rural electrification,

increased employment potential reliability and

improvement in continuity of supply and system and

removal of power cuts to a great extent. It has also led

fast development of environment in area around District

Bathinda by providing employment to about 3000

persons. Two new units of 250MW each are going to be

commissioned soon, sanctioning of which has already

being done.

The following considerations have to be examined in

detail before selection of site for a plant: -

Availability of fuel such as coal.

Ash disposal facilities.

Space requirements.

Nature of land.

Most important availability of water.

Availability of labour.

Transport facilities.

Public Society problems such as pollution.

Development of backward area.

2

PROFILE OF THE PLANT

OWNER BOARD Punjab State Electricity

Board

NAME OF THE PLANT Guru Gobind Singh

Thermal Plant

SITE LOCATION Between 129 Km and

132 Km, Milestone on

Bathinda-Barnala Road

MAIN COMPANIES TATA HONFY WELL and

EVOLVED BHEL

CONSTRUCTION IN 1992

STARTED

COMMENCE MENT IN DECEMBER 1997

OF 1ST UNIT

3

COMMENCE MENT IN AUGUST, 1998

OF 2ND UNIT

TOTAL SET UP COST 1200 Crores

TOTL CAPACITY OF 420 MW

THE PLANT

TOTAL UNITS IN 2

THE PLANT

GNERATION COST 112 Paisa/kW

OVERALL EFFICIENCY 95%

OF THE PLANT

HEIGHT OF CHIMNEY 220 Meters Multi

Flue

SOURCE OF WATER Bathinda Branch of

Sirhind Canal

4

POWER DISTRIBUTION

Electric Power Generated here is send to various sectors

through distribution center. This is the main product of the

plant, which is our nations wide requirement. Electric

Power drives all our factories, industries, Railways,

Domestic equipment etc. Overall our life is dependent on

the electric power now days.

Distribution center distributes power from

here to Barnala Sub Distribution Mansa, Bathinda, Delhi,

Ludhiana and Duri as per requirements.

RAW MATERIAL AND THEIR SOURCES

Power generation is using coal, HFS etc. as burning fuels

for the generation of steam from demineralised water.

Coal coming from West Bangal & Bihar via

Rail wagons of 3800 Kcal/kg & 35% ash contents as the

minimum requirement with rate of rupees 680/-p.tone.

&4000 Tons per Day in quantity.

Water is taken from Sirhand canal by the

tunnel link of underground 2600mm dia pipes, which is

collected in water pond of 150 arcs area & capacity

100000 cubic meters.

5

BASICS OF A THERMAL PLANT

In a thermal plant, heat energy is converted into

mechanical energy of turbine that is further converted

into electrical energy with the help of generator.

A schematic view of the simplest

steam power plant is shown in fig. A that is on next page.

The three main processes in the diagram are: -

Process AD : - Water is admitted to the

boiler, raised to boiling temperature and then

superheated.

Process DF : - The super heated steam is fed to

the turbine where it does work on blades and rotates

it.

Process FA : - Heat rejected to the condenser.

Circulating water carries a very large proportion (40-

60% of total heat).

The basic cycle of a steam power

plant considered above is called the RANKINE CYCLE.

6

7

RANKINE CYCLE ON TEMPERATURE

ENTROPY DIAGRAM

The Temperature Entropy (T-S) diagram is the most

useful diagram for illustrating certain fundamental points

about steam cycle. Ideal condition for steam cycle on a T-

S diagram is shown in the fig. That is on the page no.2

At point ‘A’ the condense is at boiling

temperature corresponding to the back (condenser)

pressure. Heat (sensible) is added to this water to raise

its temperature and pressure. At the point B, it reaches

it saturation temperature. Evaporation begins at point

B. Heat (latent because no rise in temperature between

B & C, as evident from the diagram) addition continues.

At C all the water evaporates and super-heating

commences. This is shown by the curve CD and at D,

the superheated temperature is achieved.

Steam then expands as it enters the

turbine and rotates it, as shown in the line DEF. At point

E there is no super heat left in the steam and so from E

to F there is increasing wetness. At F steam is passed

out to the turbine to the condenser and condensation of

steam takes place as represented by the line FA. At

point ‘A’ the steam has all been considered and

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condense is a boiling temperature ready to begin

another cycle.

To summaries the above :

AB - Heating of feed water (i.e. sensible

heat

Addition)

BC - Evaporation of water in boiler (i.e.

Latent heat addition)

CD - Superheating of steam (i.e. superheat

Addition)

DF - Expansion of steam in turbine, point E

Donates demarcation between super-

heated and wet steam.

FA - Condensation of steam in condenser.

PROCESS OF POWER GENERATION: -

A generating unit of thermal plant consist of boiler unit, a

turbine with accessories, a generator, a unit transformer

and other equipment all arranged to operate as

complementary part of a complete monolithic set. The

plant

Overview diagram, which shows the process of generation

of electricity, is on the next to next page.

9

ELECTRICITY GENERATION PROCESS

EXPLANATION

The coal travels by the conveyer belts from the

coal handling plant to the coalbunkers from where it is fed

into pulverizing mills; which grind the coal into powder.

The powder coal is carried from the mill by steam of air

heated air in the air heater driven by primary air fan (PA)

to boiler burners where it is blown into the furnace and

burns like a gas a force draft fan provide addition

controllable to the burners to assist combustion. The

product of this combustion is dust and ash. (Ratio of 5to 1)

the ash to the bottom of the boiler and is periodically

sluiced to mash setting pits .The dust carried in the fuel

gas to the precipitators where it is extracted by high

voltage electrodes. The dust is then conveyed to settling

lagoons or removed by the road for safe. The fuel gas

passes by an induced draft fan (ID) to the chimney. The

heat released by the burning coal is absorbed by long

length of tubing which forms the boiler valves. Inside the

tube extremely pure water that is known boiler feed water

is converted by the heat into steam at high pressure and

temperature. The steam is then superheated in further

tubes and passes to the high pressure (H.P) turbine where

it is discharged through the nozzle into the turbine blades.

10

The energy of the steam striking the blades make the

turbine rotates after passing through the high-pressure

turbine. The steam is returned to the boiler for reheating

before passing through the intermediate pressure turbine

(IPT) and to the low-pressure turbine (LP). Coupled to the

turbine shaft is rotor of the generator, a large cylindrical

electromagnet, so that when the turbine rotor rotates,

other rotor rotates with it. The generator rotor is enclosed

in the stator; which consist of large coils copper bar in

which electricity is produced by the rotation of magnetic

field created by the rotor. The electricity from the stator

winding goes to a transformer; which increase its voltage

so that it can be transmitted over the power lines into grid

system. Mean while, the steam that is exhausted its useful

energy in turning the turbine is turned back into water in

the condenser so that it can be

Used again in the boiler. Before entering in the boiler at

the economizer the water is pumped by condense extract

pumps heated in the low pressure (L.P.) heaters,

deaerated in the deaerator increased in the pressure by

boiler feed pumps and heated further in high pressure

(HP) heaters. The water passes through the economizer to

the steam drum then up through the furnace wall–tubing

before returning to the steam drum for steam separation.

The steam leaves the drum and heated further in the

super heater on its way to the HP Turbine. The condenser

11

contains miles of tubing’s through which the cold water is

constantly pumped.

The diagram showing this whole process is

shown on page no. 11& page no. 12

Plant overview

Conveyer belt

FD Fan

Heat released

12

COAL PLANT

BOILER BUNKERS

PULVERISING MILLS

BOILER BURNER

COMBUSION

CLEARED FUEL GAS PASS TO CHIMNEY VIA INDUCED DRAUGHT FAN

COAL BURN

BOILS WATER WHICH GIVES STEAM

DustAsh

Continue On Next Page

CONTINUED FROM THE LAST PAGE:-

Steam

Power Lines

13

STEAM IS SUPERHEATED

PASSES TO H.P TURBINE

TURBINE BLADES

CAUSES TURBINE TO ROTATE

STEAM IS RETURNED TO BOILER FOR REHEATING

TIRBINE SHAFT IS COMPLED TO ROTOR OF GENERATOR

GENERATOR ROTOR IS ENCLOSED IN STATOR

ELECTRICITY IS PRODUCED AT STATORWINDINGFROM WHICH IT GOES TO TRANSFORMER

EXHAUSTED STEAM ENERGY

CONDENSER USED AGAIN IN BOILER

WATER IS PUMPED

HEATED IN LP HEATERS

DEAERATED IN DEAERATOR

PRESSURE INCREASESBY BOILER FEED PUMPS

HEATED IN HP HEATERS

ECONOMIZER

STEAM DRUM

STEAM IS HEATEDIN SUPERHEATER

HP TURBINE

POWER IS STEPED UPBY TRANSFORMER

GRID SYSTEMS

PLANT OVERVIEW

BLOCKS DISCRIPTION

SUPERHEATER (SH)

Super Heater (SH) is a plain tubular, non-drainable vertical

in line spaced type, arranged for parallel flow. This super

heater (SH) is located in the horizontal path after

reheater. Next to Super Heater is Reheater System.

REHEATER SYSTEM (RH)

The reheater section is the single stage; spaced type,

continuous loop, and plain tubular, non-drainable, vertical

in line spaced type, arranged for parallel flow.

ECONOMISER SYSTEM (ECON)

The economizer system is a single block unit, is of

continuous loop plain tubular, drainable horizontal, in line

arrangement with water flow upwards and gases flow

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downwards. The economizer tubes are suspended from

economizer intermediate header, using ladder type

supports.

DEAERATOR (DEA)

The deaerator (DEA) is provided to remove dissolved

corrosive gases from feed water that goes to the boiler. It

prevents internal corrosion of boiler tubes. The oxygen is

reduced to untraceable limits by mechanical means in the

condense living the deaerator.

BOILER FEED PUMP (BFP)

Boiler feed pump (BFP) is very important auxiliary of the

powerhouse. It has to take supply of water from the

deaerator, and supply it to boiler drum against the

positive drum pressure.

MILLS

Bowl mills have been installed from pulverizing the raw

coal. The coal of maximum size of 25 mm is received in

raw coalbunkers from Coal Handling Plant. From the

bunker, this coal is fed into the mill through Raw Coal

15

Feeder. Regulating the speed of the Feeder can control

the feed of the coal mill.

CONDENSER (COND)

The condenser (COND) is a box type double pass with

divided water box design that facilitates the operation of

one half of the condenser while the other half is under

maintenance. The steam space is of rectangular cross

section to achieve optimum utilization of the enclosed

volume for necessary air-cooling section at the center

from where air and non-condensable gases are drawn out

with the help of air evacuation pumps. The circulating

water enters the water boxes from bottom and then

travels through several tubes and leaves the condenser

through upper water boxes in two distinct paths. Next to

condenser is condensate extraction pump (CEP).

CONDESATE EXTRACTION PUMP (CEP)

There are two 100% capacity condensate extraction

pumps (CEPs) provided in the system. Normally, one

condensate extraction pump runs and other is kept as

stand-by. These pumps are of vertical and centrifugal

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canister type with the driving motor. Condensate

extraction pumps have five stages.

GLAND STEAM COOLER (GSC)

The gland steam cooler is used to condense the steam

extracted from turbine glands and to maintain slight

vacuum at the turbine glands to avoid steam leakage to

atmosphere from turbine glands. It is a single pass heat

exchanger with the main condensate entering from one

end and leaving from the other end. Air steam mixture

passes over the tubes in zigzag path due to number of

baffles and thus steam is condensed there-by heating the

condensate inside the tubes.

DRAIN COOLER (DRN CLR)

Drain cooler (DRN CLR) is provided to sub cool the drains

coming from Low Pressure (LP) Heater to improve the

cycle efficiency by heating up the condensate flowing

through the tube system.

LP HEATERS (LP HTRS)

17

The LP heaters (LP HTRS) are of the surface cooled type.

They are designed for vertical mounting. These heaters

are of tube system withdrawal type; these are of four-pass

design. Condensate flows inside the tubes while steam

flows

Outside the tubes. The condensed steam is collected in

the bottom of the shell that is drained out.

H.P. HEATER (HP HTRS)

High Pressure heater is supplied heating steam from

extraction 5 taken from IP casing of turbine. The feed

water enters first in this H.P heater and after getting

heated goes to High Pressure (HP) heater 6. The feed

water flows through the tubes from coldest zone to the

hot most zones before it leaves the heater. The steam

flows from hot most zones to coldest zone and the drain

normally goes to deaerator.

ROTARY AIR HEATER (RAH)

The basic principal of operation of Rotatary Air Heater

(RAH) is the same as the liung storm type except that the

elements are stationary and the air hoods rotate with. In

the gas pass at approximately 1 rev./min. The axis of

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rotation may be vertical or horizontal but again and for

similar reasons the vertical spindle is preferred. The drive

is normally through an electric motor operating a pinion

that meshes with the rack on the outer rim of the hood

assembly.

FORCED DRAFT FANS (FD FAN)

To take air from atmosphere at ambient temp. To supply

essentially all the combustion, air can either be seized to

overcome all the boiler losses (pressurized system) or just

put the air in the furnace (balanced draft units).

INDUCED DRAFT FANS (ID FANS)

Used only in balanced draft units to suck the gases out of

the furnace and throw them into the stack. Handles fly ash

laden gases at temperature of 125 to 250oC.

ELECTROSTATIC PRECIPETATORS (ESP)

The principles upon which Electrostatic Precipitators

operates are that the dust-laden gases pass into a

chamber where the individual particles of dust are given

an electric charge by absorption of free ions from a high

voltage DC ionizing field. There are four different steps in

19

the precipitation viz., ionization of gases and charging of

dust particles, migration of the particle to the collector,

deposition of charged particles on the collecting surface,

dislodging of particles from the collecting surface.

VARIOUS CYCLES INVOLVED IN

POWER GENERATION

PRIMARY AIR CYCLE: -

The primary air, generated by PA (primary air) fans, is

used to carry the pulverized coal from the coal mils to the

furnace.

The Primary Air (PA) fans are two in number. A

header called the PA fan duct of the air is made and two

tapings are made from this header. One is passed through

the AIR PRE-HEATER A and B, which, using the heat of the

outgoing flue gases, heats the air, now called the hot

primary air. This hot primary air is now divide into six

parts A to F and then sent to the six coal mills by making

a hot primary air header.

The other tapping of air called the cold primary

air is also made into a cold primary header and then

divided into six parts A to F to be sent into six mills.

20

Now lets consider the action of primary air on

the mills by considering, say, mill A. Hot primary air A and

cold primary air A pass through respective valves in their

pipes before entering the coal mill. The valve is installed

as the inlet flow temperature is to be maintained at

>175ºC and the flow of the air flowing in the mill is to be

at 54-tons/hr.the outlet temperature is to be maintained

at >65ºC &< 10ºC.

From the mill, four feed outlet are taken,

carrying the coal to furnace. As these are six mills, so

there are 24 feeds to furnace.

The feed from each mill enters the furnace

at 4 different corners but at the same elevation or height.

The feed from other mills also enters the furnace at

corners but at different elevations.

All the feeds from the mill open equally.

Now consider only one corner of the furnace. The feed

from mill A enters the corner of the lowest elevation and

those from mill F at highest elevation. The other feed is

between them. In between feeds A & B, C& D, E & F, there

are oil guns called feed AB, CD, and EF respectively.

Below A and above F, There are auxiliary air inlets in the

furnace. The primary air cycle is shown on the next to

next page.

21

SECONDARY AIR CYCLE: -

The forced draft fans are used to generate the secondary

air, which is used to help in the ignition and burning of the

coal in the furnace. A common header is made of the two

FD fans (A&B) and this passed through the two air pre-

heaters, which heat the air using the heat from the flue

gases, so that the cold air doesn’t bring down the

temperature of the furnace. The secondary air for

combustion is preheated up to 317oC by means of

regenerative air-heaters (Rotary Air Heaters). The air

heater air out ducts are interconnected to provide a

balanced air flow to the furnace and to make it possible to

operate the unit at reduced load if one fan is out of

service.

22

Distribution of secondary air to Wind Box compartments is

controlled by the secondary air dampers. The steam coil

air pre-heaters (SCAPH) one each at the outlet of FD Fans

& before RAH has been provided to avoid the corrosion of

RAH by increasing the temperature of secondary air

entering the RAH when the boiler is initially lighted up.

The secondary air path is shown in fig. That is on the next

page.

Air I/l

PRIMARY AIR CYCLE

23

PAFANA&B

RAHA&B

MILLSA-F

FURNACE

RAHA&B

SCAPHA&B

FDFANA&B

Air I/l

SECONDARY AIR CYCLE

AIR CYCLE

FLUE GAS CYCLE: -

Flue gases travel upward in the furnace and downward

through the rear gas pass to the economizer and air

heaters. In the economizer, the some heat of flue gases is

utilized to heat the feed water before it goes to drum.

Further in the air heaters, the residual heat of the flue

gases is utilized to pre-heat the secondary and primary

air. From the air heaters, the gases pass through the

electrostatic precipitators (ESP) and induced draft fans to

the stack. Interconnections of the gas ducts at inlet and

outlet of electrostatic precipitators are provided.

24

FLUE GAS CYCLE

25

FURNACE RAHA&B ESP

ID FANA, B, C

CHIMNEYOR

STACK

WATER CYCLE: -

The steam after working in three casings of the turbine i.e.

HP, IP & LP casings is condensed in the surface condenser

installed just below the LP exhaust hood. The condensate

is collected in the bottom portion called ho well from

where it is pumped into the Deaerator by condensate

extraction pump (CEP) through different heating stages

through which condensate flows and get heated up

gradually before finally reaching the Deaerator. The

various heating stages are Gland Steam Cooler, Drain

Cooler, and LP Heater (1, 2, 3) Deaerator. The

approximate temperature rise of condensate after passing

through above heating stages is from 40/45 at hot well to

166oC at the Deaerator (at full load).

The condensate coming from LP heaters passes the tubes

of vent condenser. The steam transfers its heat to

condensate flowing within the tubes and gets condensed.

The non-condensable gases along with some steam go out

of the equipment. The drain (condensed steam) is

returned to the deaerating header.

The condensate after leaving the

deaerating header enters the feed storage tank. From

feed water tank, the boiler feed pumps takes suction of

26

feed water thorough booster Pumps and discharge is fed

to the boiler drum after passing through different heating

stages viz. HP heaters (5, 6) and feed water regulation

station (FW REG STN).

MAIN WATER CYCLE

27

FM DMM/U

COND. CEPA&B

GSC DRNCLR

LPHTR’S

DEABFPA, B, C

HPHTRS 5,6

FWREG STN

FURNACE

steam

STEAM CYCLE

Steam is that part of the whole process cycle in which the

fluent is steam i.e. part of the cycle containing steam.

Steam is first of all generated in the boiler with the help of

coal as a principal fuel. If it is not present in the adequate

amount or not of high purity then heavy furnace oil (HFO)

and light diesel oil (LDO) is used to produce heat in the

furnace.

The heat energy supplied in the furnace is

absorbed by the water walls and gets heated up. This

gives rise to the formation of steam bubbles in the water

walls and the risers. The cold water in the drum there

continuously displaces the moisture of steam bubbles and

water by destabilizing a natured circulation. With the help

of super heater (SH) the steam is super heated and

passes to the HP Turbine. For high efficiency, the turbine

is divided into three stages viz. HP Turbine, IP Turbine and

LP Turbine. Now at the starting the temperature of the

shaft of the turbine is less and at once increase in

temperature may cause ‘Sag’ in it therefore few cycles of

heated steam passes through the HP BP so that the

conductor in the turbine may achieve the equivalent

temperature of the steam by this there will be no loss of

28

heat due to temperature difference. Through HP BP it

again passes through the furnace and there it reheats

with the help of Repeater (RH) and then it passes to the IP

Turbine at a temperature of about 551oC . From here it

passes through the LP Turbine that rotates the coils of the

generator and electricity has been produced. Like HP BP,

LP BP is present as a direct passage of heat from IP

Turbine to condenser where this steam is again changed

into water.

MAIN STEAM CYCLE

29

FURNACE

ECON SH

RH

HP BP

HPT

IPT

LPT

GENERATOR

COND LP BP

WORKING OF THERMAL POWER PLANT AT G.H.T.P.

Coal received from collieries in the rail

wagons is mechanically unloaded by wagon tippler and

carried by belt conveyor system to crusher house

underground. In crusher house the coal is crushed up to

25mm. This coal is taken by belt conveyer to raw coal

bunkers near coal mill. The coal is then milled to powder

form having up to 0.5mm to1.0mm dia. There is a raw

coal chain feeder that regulates quantity of coal from

bunkers to coal mill where coal is pulverized as said

above. That pulverized coal is then pushed to the boiler

furnace by pressurized primary air from corner feeders.

This furnace have water tube wall all around through

which water circulates. Water is converted into steam by

heat released by combustion of coal. The oils

L.D.O.&H.F.O are used in combustion of coal forced by

forced draught fan. That air is sent in the boiler furnace

after heating in air heater by using the heat of flue gases.

The greatly heated steam and water

is sent to boiler drum, where the water is separated from

steam and the dry steam is sent to the T.G.set, and the

water is again sent to reheater and economizer.

30

The steam having 130km/m2 to144km/m2 pressure and

5400 c temperature is sent to H.P turbine. Turbine is made

from Germany which uses high pressure steam and

rotates at 3000rpm.The steam used in H.P.Turbine is lost

its heat up to 2400 c so to reheat i.e. to raise again the

temperature and pressure of the steam. The steam is

passed through the reheater and continuously sent to

H.P&L.P turbine, made by B.H.E.L., rotated on the same

shaft with 3000rpm. The steam from LP turbine is taken

out in a vacuum condenser having (-) 0.9kg/cm2 vacuum.

Here the steam is condensed by cold water pipes

ciculation.The condensed steam in form of hot water is

put into the hot wall. From where it is again feed into the

boiler drum through the deaerator, LP heaters, HP

heaters, BFP, Economiser etc. The condensating water,

which is used to condense steam, takes heat from steam

and it becomes hot. That hot water is taken to cooling

tower where it is dropped from 10m heights to cool water

by using natural air draught. This circulation is made by

C.W.pumps

And cooling is done up to 100 c.

The products of combustion of

furnace charge are flue gases and ash. About 20%of the

ash falls in the bottom ash hopper of the boiler and is

31

removed mechanically by mixing with water. The

remaining ash carried by flue gases is separated in the

Electrostatic Precipitator where the ash is electro statically

evacuated

And this dry ash is dumped in the ash disposal area. The

cleaned flue gases are left to the atmosphere through

220m high chimney using I.D.Fan.

The turbines are coupled to the

same shaft upon which the generator is coupled. The

Three phase generator produces 3-phase supply and

which is pumped to the power grid system through

generator transformer by stepping up the voltage which is

further send for distribution.

The raw water is taken from

‘Sirhind’ Canal to ponds and after that some amount of

water goes to the boiler through D.M. plant and the

remaining water is clarified and used for the cooling

purposes.

32

33

SYSTEM DESCRIPTION

G.H.T.P.Thermal Power Plant consists of various systems.

These are the following systems: -

Coal Handling System.

Fuel oil system

Ash handling system.

D.M. Plant.

Emergency Power supply system.

Control & Instrumentation system.

Data Acquisition system.

Power supply distribution system

COAL HANDLING SYSTEM

G.H.T.P.Thermal Plant is coal-based power plant. The

annual requirement of coal for 2 units based on specific

fuel consumption of 0.60 kg/kwh is 1.381 million

tones .The conveying and crushing system will have the

same capacity as that of the unloading system 1000

TPH.The coal comes in the coal plant in large pieces. The

34

coal is fed to the primary crushers, which reduces the size

of coal pieces from400mm to 150mm size. Then the coal

is sent to the secondary crushers through forward

conveyors be crushed from 150mm to 20mm as required

at the mills. Then the coal is sent to mills through

coalbunkers .In mills coal becomes in powder form, which

is sent to the boiler with the help of priamary air fan. The

coal is burnt in the boiler. Boiler includes the pipes

carrying water through them. Heat produced from the

combustion of the coal is used to convert water in pipes

into steam. This steam generated is used to run the

turbine. When turbine rotates the shaft of generated

which is mechanically coupled to the shaft of the turbine

get rotated and so 3 phases electric supply is produced.

FUEL OIL SYSTEM

Fuel oil is normally used for start up and for flame

stabilization at low load. Initially in the boiler either L.D.O.

or H.F.O. is combusted before the combustion of the

crushed coal from the mill.

Light Diesel Oil (L.D.O.) does not require

preheating but Heavy Fuel Oil (H.F.O.) requires preheating

because H.F.O. is very much viscous.

L.D.O. or H.F.O. are used initially because this

oil has less heat of combustion then coal. Heat liberated

35

from the combustion of these oils is used for starting

combustion of coal as soon as coal starting combustion

L.D.O. and H.F.O.is stopped and coal is supplied

continuously from the fuel guns in to the boiler.

The H.F.O. is preheated by using the heat

of burnt gases, which is coming from boiler of the 2nd Unit

through Chimney.

ASH HANDLING SYSTEM

When the coal is burnt in the boiler nearly 35% of the ash

is liberated in the addition with another burnt gases.

These ash and gases are coupled out by the reduce draft

fan from the boiler E.S.P. is between the boiler and

I.D.Fan. E.S.P. contains charge electrodes that attract the

ash particles and the collect ash this ash is sent for

disposal.

DEMINERALISED PLANT (D.M)

A Demineralised water treatment plant is provided for

supplying make up water to the boiler.

Water as it occurs is never pure as

whatever may be the source always contain

impurities .the major impurities of water are: -

Non-ionic & undissolved

36

Ionic &dissolved

Gaseous

In the DM plant these impurities are removed chemically

& Demineralised water is sent to the boiler.

EMERGENCY POWER SUPPLY SYSTEM

For the safe shut down of the plant under emergency

conditions i.e. in the case of total power failure diesel

generating sets are purposed to be installed for meeting

the power requirements of the essential auxiliaries.

CONTROL&INSTRUMENTATION

The function of the control & instrumentation system is to

add the operator in achieving the safe and efficient

operation of the unit. The operator is to be provided with

the adequate information considered essential for start

up, normal operation, planned shut down and emergency

shutdown of the unit.

Centralized control of the boiler

&turbine generator unit from a centrally located Unit

Control Board (UCB) room is envisaged. It would be

possible

37

To start or to stop all electrically driven unit auxiliaries

&power operated valves and dampers from UCB expect

where recommended, otherwise, by the main equipment

suppliers.

DATA ACQUISITION SYSTEM

In line with the modern practice of centralized monitoring

and control of large capacity power plants Data

acquisition system (DAS) shall be provided for monitoring

and logging of different parameters of steam generator,

turbine, important temperature points of H.T & L.T motors,

generator & other auxiliaries of the unit.

The system shall monitor, log, the

various parameters at different time e.g. at the time of

start up, shut down, normal run sudden load throw off

positions.

The electronic system of DAS shall be of high speed and

equipment with alphanumeric and trend display CRT and

alphanumeric logging printer.

POWER SUPPLY DISTRIBUTION SYSTEM

Power supply/control supply panels with adequate no. Of

spare feeders shall be provided to meet the requirement

of primary instruments, secondary instruments, controls

38

panels, DAS, sequential control system protection and

interlock system. Suitable arrangement for automatic

changes over from normal supply to stand by supply and

provision of uninterrupted power supply (UPS) to meet the

essential load requirements shall also be provided.

TDC-3000

TDC 3000 organized by process plant instrumentation and

control needs flexibility. Before going in detail of the TDC-

3000 (DCS) we should familiar with the following objects.

AREA UNIT POINT CONCEPT: -

In TDC-3000 plant instrumentation is classified into areas

and plant can be sub-divided into max. 10 areas.

Collection of points on geographical or

functional sets is identified as units, which in terms are

assigned to respective plant area.

In one area max. 36 units can exist.

Area boiler subdivided into 5 units.

Feed water system (FW)

39

Steam system (ST)

Flue gas system (FG)

Combustion air system (CA)

Fuel system (FU)

Each unit will have respective set of process data points.

AREA UNIT POINT DIAGRAM

POWER PLANT

40

BOILER TURBUNE

FU ST FG CAAA

FU

TIC100

FIC100

TIC 100and FIC100: -

Points belonging to steam system unit of boiler area.

Parameters of process points of the total plant (all areas)

can be viewed on any of the universal station (with

operating and universal personality), but process

parameter manipulation and alarm reporting are area

specific.

ALARMS AND MESSAGES: -

Alarm and messages will only reported for the points,

which are belonging to the signed units. Whose area

database is currently present in the universal station?

Alarm acknowledgements console wide function.

MANIPULATION OF PROCESS PARAMETERS: -

41

These are at the operator accessing level. Manipulation of

parameters of the process points will be allowed only for

the points, which are belonging to the assigned units,

whose area database is currently present in universal

station.

Manipulation of parameters of the

process points that are not belonging to the assigned unit

to the area database currently present in the universal

station, will be allowed only at the access level higher

than that of operator’s access level.

ABOUT THE AREA UNIT POINT

ORGANISATION: -

1.CONSOLE STATUS: - Unit display target is used to

determine units configured and assigned to the area

database present in the universal station.

2.SYSTEM MENU:-Organization survey menu target to

determine the points attached to individual units of the

area.

WHAT IS TDC3000: -

Total distributed control system (TDC) 3000 is a

Honeywell make DISTRIBUTED CONTROL SYSTEM.

42

WHAT IS DISTRIBUTED CONTROL

SYSTEM:

Functionally and physically separate automatic process

controllers, process monitoring and data logging

equipment, connected with each other to share relevant

information for optimum plant control is called

DISTRIBUTED CONTROL SYSTEM.

HOW DCS CAME IN TO EXISTANCE?

Customer in process industry resulted in advancements in control and instrumentation(C&I) technology. This advancement and their advantages and disadvantages are shown in fig.

43

Development of (C&I) technology from pneumatic to

electronic equipment was itself a very big change. In

electronic C&I equipment, various functional blocks were

used to function under vinter dependent circuits and

control logic.

At this stage these functions were

interconnected by signals through multiple cables.

44

Application of microprocessor and

digital communication technique made it possible to

distribute the C&I equipment distributed geographically

and functionally, reducing multiple cable into single cable.

This inter connection of processing function blocks of a

system is termed as a network (N/W)

The signal level and states previously used through

multiple cables are now digital information packets,

multiplexed in time, around the N/w, sent and received by

connected functional processors.

Further advancement allowed the distribution of C&I

system of various type of function n/w like: -

Process N/w

Supervisory N/w

Plant information N/w

45

Plant wide C&I automation dependent on these N/w’s,

emerging as a DCS.

The important benefit of DCS, which is

making it popular is the fact that even failure of processor

or a N/w will not result in failure of other processors or

N/w’s of the system respectively.

WHAT ARE THE FUNCTIONS

DISTRIBUTED AROUND A DCS?

Following diagram shows the function blocks in a DCS with

their use:

46

WHAT IS THE MAIN BENEFITS OF DCS

OVER CONVENTIONAL C&I EQUIPMENT?

Reduction in cabling in control room.

Physically and functionally separate modules.

More uniform operations and tighter controls.

Excellent information management.

Better integration of plant controls.

Considerable reduction over maintenance efforts.

WHEN &FROM WHOM THE FIRST DCS

WAS MADE AVAILABLE?

47

First DCS came in 1974 from HONEYWELL. It was named

then TDC 2000 (total distributed control 2000). The

communication link in TDC 2000 is called DATA HIWAY.

HOW TDC 3000 THEN CAME INTO

EXISTANCE? AND HOW IT IS

ORGANISED?

Further advancement resulted in release of TDC3000 in

1984. This now release of DCS from HONEYWELL

contained new Supervisory LOCAL CONTROL NETWORKK

(LCN).

EARLY TDC 3000 SYSTEM ACHITECTURE:

-

48

HONEY WELL TDC 3000 is a data acquisition and control

system that can be tailored to meet the user specific

requirements. It can be small system with just a handful

device, or it may be highly complex system with hundreds

of devices and several kinds of communication networks

interconnecting these devices.

The LCN connected to UNIVERSAL

STATION (US) is used for man-machine interface and

HISTOY MODULE (HM) is used for storage of process

system related information.

Process connected controllers like BASIC

CONTROLLERS (CB) and ADVANCED MULTI FUNCTIONAL

49

CONTROLLERS (AMC) are linked to LCN through the

process N/w DH and an interface HIGHWAY GATEWAY

(HG).

Further development introduced a new

process N/w UNIVEWRSAL CONTROL N/w (UCN) in

1989.The process N/w is connected to LCN through

NETWORK INTERFACE MODULE (NIM). Capacity of NIM is

higher than HG.

The new TDC 3000 system architecture after inclusion of

UCN and process connected boxes is shown in fig below: -

50

APM and LM are the UCN connected automatic process

controllers

In various process plants TDC3000 is

practically implemented with redundant communication

medium (cables), gateway and process controllers.

WHAT IS TDC 3000 PROCESS

OPERATION:

This means, monitoring and operating the process plant

using universal station of TDC3000 system, this includes: -

Calling various displays.

Monitoring status, values, trends, modes and event on

displays.

Manipulating parameters.

Responding to various alarms and messages.

Taking various hard copies on printers.

51

Storing important process related information.

Sensors and actuators of various kinds from the process

plant are connected to process controllers through N/w’s;

process information (values, status, modes, alarms etc.) is

made available on the US displays.

From US it is possible to manipulate direct

actuator drive, values and mode change of different

parameter in automatic control function, also various

commands to controllers and other N/w’s connected

function blocks can be sent from the US.

Monitoring and operation of TDC3000 system

itself is also done at US. Along with process operation,

system operation aspects are also practiced in TDC3000

process operation session

UNIVERSAL STATION

Universal Station is the man machine interface of

TDC3000 system. In our subsequent session we will be

learning and practicing above-mentioned activities from

US.

52

US is a single window to the process as well as

TDC3000 system allow the operator both monitored

and manipulate the process the system.

System configuration is also done from Universal

Station.

Before operating TDC 3000 universal station we should be

familiar with the following concepts: -

Universal station equipment.

Universal station personality.

The Access level type of universal station for

operating security.

DIFFERENT PERIPHERAL CONNECTED

TO THE UNIVERSAL STATION (U.S).

Color video display monitor with touch screen facility.

Operator’s keyboard.

Electronic card rack.

Engineer keyboard (optional).

53

Cartridge/floppy drive (optional).

Printer (optional).

Trend pen recorder (optional).

Video copier (optional).

Track ball (optional).

DIAGRAM OF US IS SHOWN BELOW: -

1 . COLOUR VIDEO SCREEN DISPLAY MONITOR

WITH TOUCH FACILITY: -

Consist of 48cm. (19-inch) high resolution colors CRT

and associated electronics. Each CRT has brightness

and contrast thumb wheels and a degaussing push

button on the bezel. The color video display monitor

shows system displays and process displays.

54

The touch screen option on the color video display

monitor is implemented using infrared sensor and

transmitters that are located in the bezel of the CRT

screen.

2.OPERATING KEYBOARD: -

Contain 147 touch keys that initiate actions. In this 85

are user configurable function keys & 61 are standard

operated function keys.

Red and yellow color lamps (LED’s) are included on

certain keys to indicate important process and

TDC3000 alarm systems.

User Configurable keys are 85 buttons on left side of

operator keyboard, that the user can define or

configure to perform certain functions, such as call up

of certain critical frequently displays. Cross screen

displays or to activate particular action sequence.

Standard Output function keys.61 keys on the right side

of the operator keyboard.

These are further divided into five groups:-

Standard Process displays call &display control keys.

Standard system displays call &system function keys.

Standard process alarm management keys.

Standard operator control keys.

55

Standard numeric keys.

AC POWER ON/OFF AND ELECTRONICS

MODULE

It is the part of the US, helps in AC &DC On/Off control,

main electronic processors, memory, and Local control

network (LCN) interfaces and other interfaces to

connected peripherals and optional devices. Also, the DC

power supply, fan module and necessary interconnecting

cable assemblies for the US are also housed in the same

unit.

4.ENGINEER KEY BOARD: -

These are of two types: -

One is fixed in front of operator keyboard.

2nd one is plugged into appropriate model of US.

5.CARTRIDGE AND FLOPPY DISK DRIVE: -

Used for random data storage. Both type of disk drives

are compact, easy to use, data storage and retrieval

devices that accept removable magnetic media.

56

Disk drive: - 5.25-inch floppy diskette called floppy disk

drive. A floppy disk is a flexible; double sided, double

density, enclosed in a sealed jacket and has storage

capacity of 1.2-MB.

Cartridge disk drive accepts cartridge disk. The

cartridge disk is compact and high capacity disk rigidly-

encased in plastic casing. A cartridge drive has storage

capacity of 20/40/150 MB.

6.DOT MATRIX PRINTER: -

Take B/w hard copy of various processes & it can print

Logs Reports, Trends and Journals.

Whatever is on the VDM screen, including Graphics?

A record of alarms.

7.TREND PEN RERCORDER: -

Record continuous trend of process values on the

recorder paper.

Up to 8 trends pen can be driven by US.

The trend pen recorders can be mounted on the

universal station within full view of the operation.

57

8.VIDEO COPIER: -

Video copier is an optional colour copier, which can be

attached with a US to take hard copy of current display

on the VDM screen.

9.TRACK BALL: -

Cursor pointing and target selection device

Front mounted by the operator keyboard panel.

UNIVERSAL STATION PERSONALITY

To service man machine interface needs, following two

software functions termed, as personalities are available

for Universal station (U.S).

OPERATOR PERSNALITY is used for process operation

from US.

58

ENGINEER PERSONALITY is used for TDC 3000

system configuration for process control engineering

and system maintenance.

With the operating personality present in US,

the operator can: -

Monitor and manipulate process parameter including

startup and shut down of plant units.

View and manage the process and system alarm and

message.

Display and print continuous and discontinuous

histories.

Display and print process trend and averages.

Display and print reports, logs, and journals.

Copy data to/from floppy diskettes or cartridge.

Monitor and change status of system equipment in the

control room and near the process.

Load operating programs and data busses from a

history module, floppy diskettes, or cartridges.

Functions of Operator & Engineer

personalities in single software packed are also available

which is termed as UNIVERSAL PERSONALITY (U.P).

59

SYSTEM AND PROCESS OPERATION

FUNCTION:

Monitoring and controlling continuous and

discontinuous process operation.

Annunciating and handling alarms.

Display and printing trends and logs, journals and

reports.

Monitoring and controlling system status and

diagnostics.

PROCESS ENGINEERING FUNCTIONS: -

Network configuration.

Building process database.

Building custom graphics.

Designing reports.

Preparing control language (CL) programs.

SYSTEM MAINTENANCE FUNCTIONS: -

Diagnosing system problems.

Displaying and printing information required during

troubleshooting.

60

LOADING OF UNIVERSAL STATION: -

Loading is the task of putting any one of the above

mentioned personality programs (OP/EP/UP) in the

memory of US. After the loading a personality, the US can

serve as the man machine interface with appropriate

functions.

61

Loading of US is required on the following circumstances:

On initial start up of US.

Power resumption after power failure

Change of personality program is in the US

After resetting the malfunctioning US.

The US is loaded with operator personality in following

steps:

Step 1: A. check US powered ON

B. Adjust the contrast and brightness controls on

VDU panel to the prompt.

C. Check the prompt on the left top of the

powered

ON universal station screen.

D. If the prompt is present then go to step 2

Else press RESET button on OKB and wait for

Prompt on US.

Step 2: A. Press LOAD key on OKB

B. Check on the US screen

If “N, 1,2,3,4,X?” displayed then go to step 3

Else contact the trainer.

Step 3: A. Type “N” and press ENTER key on OKB.

B. Check on the US screen;

If “OPR, ENG, X?” displayed then go to step 4

Else contact the trainer.

62

Step 4: A. Type “o” and press ENTER key on OKB.

B. Check on the US screen.

If “load in progress” displayed then go to step

5

Else contact the trainer.

Step 5: wait till “CONSOLE STATUS” display appears on

the

Screen.

After the console status display appears on the US screen,

US takes little more time to settle down with the

personality programs.

UNIVERSAL STATION OPERATIONAL

SECURITY: -

Following operational security is implemented in universal

station: -

63

Checking each data entry for the right type. Universal

station checks each data entry from keyboard for the

right type required for the operation.

Restricted access to TDC3000 functions and database

like operating parameters, configuration data and

programs.

Following three access levels designed for the restricted

access to TDC3000 database are shown below in figure: -

THREE ACCESS LEVELS ARE GIVEN BELOW: -

Operator level

Supervisor level

Engineer level

64

Operator level: -permits the user to effectively monitor

and manipulate process parameters during normal

operation, but doesn’t permit changes to sensitive process

parameters.

Supervisor level: -permits user to alter sensitive process

parameter and permit all the functions allowed at the

operating level.

Engineer level: - permit user to access the entire data

base to perform process and system configuration

functions and programs along with all the functions

allowed at the operate and supervisor level.

Level of access is determined by the

keyboard, key-switch position, access level position is

marked on the key- switch panel.

Following key types enables key-switch positions:

Supervisor’s key

Engineer’s key

SUPERVISOR’S KEY

It enables the access key switch to supervisor level.

65

ENGINEER’S KEY

It enables the access key switch to engineer level. This

key can enable the key switch to supervisor level also.

Without a key, the key switch remains enabled for the

operator level access. The access key can be removed

from the key switch only by bringing the key switch

position back to the operator level.

One more special level of operational security can be

configured called view only.

VIEW ONLY

This level of access allows call up of various displays on

US screen for viewing, but does not permit any data entry.

TDC OPERATOR CONSOLES

The group of universal stations is called an operator

console.

66

Universal stations are combined to:

Provide the required area and unit specific

perception of the process plant to the operator.

Collect methodical responses from the operator for

the process plant area and unit specific operations.

Printers, floppy /cartridge drives and trend pen recorders

attached to respective us can be shared within an

operator console.

An operator console can contain maximum ten US with or

without respective optional equipment.

US’s belonging to one console needs not to be located at

the same place.

Alarm acknowledgement is console wide.

OPERATOR’S KEY BOARD

The operator’s keyboard with its key organization is

shown below:

67

It consists of user configurable function keys& standard

operator function keys.

DESCRIPTION OF STANDARD OPERATOR

FUNCTION KEYS.

It is subdivided into five types of keys:

68

Standard system displays call & system function

keys.

Standard process display call &display control keys.

Standard process alarm management keys.

Standard process operator control keys.

Standard numeric key.

STANDARD SYSTEM DISPLAYS CALL &

SYSTEM FUNCTION KEYS.

69

SYST STATS : System status key calls up the system

status display on US. The red lamp of the key blinks when

there is an unacknowledged system alarm and remains

steady ON when all console alarms are acknowledged but

not removed.

CONS STATS: Console status key calls up the console

status display on US. The red lamp of the key blinks when

there is an unacknowledged console alarm and remains

steady ON when all the console alarms are acknowledged

but not removed.

RECRD: Trend pen recorder key activates trend pen

recording of selected point on the trend pen recorder. The

red lamp of the key becomes ON while recording is in

70

progress. Pressing the key again terminates the recording

and lamp switches OFF.

FAST: Fast update key causes the update rate for

process related display information to increase to 2-

second interval instead of the standard update rate of

once in 4 seconds. Red lamp of the key becomes ON when

fast update is selected. Pressing the key again terminates

the fast update and the lamp switches OFF.

CANCL PRINT: cancel print key is used to abort any

currently printing output on any printer in the console.

When pressed, the prompt asks the operator to enter the

console related printer number. Cancel print does not

function across stations with different personalities.

PRINT DISP: print display key is used to print the

current screen display on the assigned printer.

PRINT TREND: print trend key activates trend printing

for the selected point. Trend for all points in an operating

group can be printed on the dot matrix printer.

SYST MENU: system menu display calls up the system

menu display.

71

LOAD: load key is used to initiate the Universal Station

for personality loading. It works only when the US is not

having any personality loaded in its memory and is in

POWER ON condition.

STANDARD PROCESS DISPLAYS CALL &

DISPLAY CONTROL KEYS

These are the sixteen keys located at the left column of

the standard function keys. The diagram is shown below:

72

GROUP: Group display key calls up the required group

display on the Universal station screen. A group number is

required to be entered after pressing of the key.

DETAIL: detailed display key calls up the detail display

of required point on the universal station screen. A point

ID is required to be entered after pressing this key.

73

UNIT TREND: unit trend key calls the unit trend display.

A unit ID is required to be entered after pressing this key.

TREND: trend key calls up the trend of the selected

points on the group display currently shown on the

Universal station.

BATCH: function of this key is deferred.

GOTO: go to key used to select a point on the group

display. A point number (1to8) is required to be entered

after pressing this key.

SCHEM: Schematic key calls up a schematic display on

the universal screen. A schematic name is required to be

entered after pressing this key.

HELP: Help key calls up the pre configured display for

showing required help associated with current display on

the universal station.

DISP SET: not implemented.

74

HOUR AVG: hourly averages key calls up the hourly

average of process values of the points from the group

display, currently showing on the universal station screen.

PRIOR DISP: prior display key calls up the display that

showing immediately before the current display on the

universal station screen.

ASSOC DISP: associated display key calls up the

configured display associated with the current display on

the universal station screen.

DISP BACK: display back key calls up next lower

numbered display within the same type of display

currently showing on the universal station screen.

DISP FWD: display forward key calls up next higher

numbered display within the same type of display

currently showing on the universal station screen.

75

PAGE BACK: page back key calls up the next lower

numbered page of a multi page display currently showing

on the universal station screen.

PAGE FWD: page forward key calls up the next higher

numbered page of a multi page display currently showing

on the universal station screen.

PROCESS ALARM MANAGEMENT KEYS:

There are the middle eight keys in lower rows of the

standard function keys. These keys are used for alarm

management. Diagram showing these keys is shown

below:

76

ACK: alarm acknowledges key is used to acknowledge

the process and system alarms for the console. Details of

use of this key will be covered in alarm management.

77

SIL: silence key is used to silence audible alarms in the

console. Pressing this key dose not ACKNOWLEDGE the

alarms.

MSG SUMM: message summary key calls up the

message summary display on the universal station screen.

The red lamp of the key blinks on the presence of

messages that require operator acknowledgement.

Steadily ON lamp indicates the presences of a message

acknowledged but requires operator

confirmation/cancellation.

ALM SUMM: alarm summary key calls up the area

alarm summary display on the universal station screen.

The red and yellow lamps of the key represent different

alarm priorities. On the occurrence of the process alarm

the respective priority lamp blinks for the operator

attention & requires operator acknowledgement.

ALM ANNC: alarm annunciator key calls up the alarm

annunciator display on the universal station screen.

MSG CONFM: message confirmation key is used to

confirm a message currently displayed on the message

summary display.

78

MSG CLEAR: message clear key is used to clear

messages that have been acknowledged and confirmed

on the message summary display.

UNIT ALM SUMM: unit alarm summary key calls up

the unit alarm summary display. A unit ID is required to be

entered after pressing this key.

STANDARD PROCESS OPERATOR CONTROL KEYS

79

These are the right side fifteen keys of the standard

operator function keys. These keys are used to change the

process parameter currently selected on the universal

station display.

80

MAN: manual mode key used to change the operating

mode of the selected point to manual mode of operation.

AUTO: auto mode key used to change the operating

mode of the selected point to automatic mode of

operation.

NORM: normal mode key used to change the operating

mode of the selected point to normally configured mode

for operation.

SP: set point key used to initiate set point value changes

of a point. A value is required to be entered either by

numeric keys or by raise/lower keys after pressing this

key.

OUT: output key is used to initiate analog or digital

output value changes of respective points. A value is

required to be entered either by numeric keys or by

raise/lower keys after pressing this key.

SLOW RAISE: slow raise or digital state (ON) change

key.

SLOW LOWER: slow lower or digital state (OFF) change

key.

81

FAST RAISE/FAST LOWER KEY: fast raise /lower

keys are used to fast increment/decrement the selected

value of the point. When the key is pressed fast increment

/decrement in value results every 2/3 of a second by

2,3,5,10%of the full scale depending on the system

configuration.

CLR ENTRY: clear entry key clears an entry made

before the ENTER key is pressed.

SELECT: select key is used to select an item at the

current cursor position.

TAB KEYS: tab keys are used to position the cursor on

the universal station screen. On pressing these keys

cursor can be moved horizontally left/right or vertically

up/down. If the key is held down the cursor movement is

continuous.

82

STANDARD NUMERIC KEYS

These are the 13 keys centrally located on the standard

operator function keys & are used to enter numeric

values. The numeric keys are shown below:

83

The ENTER key is pressed to complete the data (numeric

as well as well alphabetic keying) entry.

TOTAL PLANT SOLUTION

The total plant solution TPS system consists of a local

control network& at least one process network. There are

three possible process networks, the Data hiway, the

Universal Control Network (UCN)& the programmable logic

controller (PLC) subsystem.

Each of the process networks has an interface

(called a “gateway”) that allows it to communicate with

the Local Control Network, which is where TPS work

station are located. The gateway for universal control

network interface is called the network interface module

(NIM)& the gateway for the Programmable Logic

Controller subsystem is called the PLCG.

The process network (Data Hiway, Universal

Control Network, Or Programmable Logic Controller

Subsystem) transmit process data from/to process

connected devices such as controllers & data aquisation

devices (such as temperature, flow & level) through their

gateway to local control network. This makes it possible to

see what is happening at the process without leaving the

workstation, on the local control network. TPS workstation

84

can be Universal Station Or Global Universal Station

(GUS).

Combination of these devices is also possible.

TOTAL PLANT SOLUTION SYSTEM

OVERVIEW

85

THE MAJOR COMPONENTS OF TPS

SYSTEM ARE: -

UNIVERSAL CONTROL NETWORK (UCN)

The communication channel for the advanced process

manager is called universal control network (UCN) .The

UCN is the platform for processors I/O connections to the

TDC 3000.

It is high speed, high accuracy & high

security process control network. It is peer to peer

communication capability allow for easy sharing of

process data making it convenient to implement

sophisticated control schemes.

The UCN features a 5-mega bit per second

Carrier Band Communication System with a token bus

network. It is designed to be compatible with IEEE and ISO

standard. UCN communications are consistent with the

growth and direct of evolving international standards,

86

appropriate honey well extension for secure process

applications.

The UCN uses redundant coaxial cables

and can support up to 32 redundant devices. The UCN

support peer-to-peer communication for sharing data

between devices on this network & allowing greater

coordination of control strategies. This feature enables

sharing information among advanced process manager,

process manager, and logic manager on the network (UCN

process connecting device) and local control network

modules such as history module, application module and

plant network module, thus offering tremendous power

and flexibility in implementing advance coordinated

control strategies.

The UCN is connected to single or multiple

LCN’s using network interface module (NIM). Up to 20 UCN

and data Hiway can be connected to the same LCN. At

LCN all of the process data from this process network is

available for the standard TDC3000 operate, control

history and management functions. For example, both

UCN & data Hiway based information can be combined

into the sane group and custom the graphic displays. Or

accessed for history or more advanced control functions

as needed.

87

FUNCTIONAL DESDCRIPTION: -

The universal control network provide a power

communications platform for efficient secure real

time process communication .as a leader in a

process control, HONEYWELL has extensive,

expensive with real time process network

LOCAL CONTROL NETWORK (LCN)

The TPS system consists of many different hardware

modules. These modules are dependent on one another

and require efficient and reliable communication paths

between them. LCN is basically used for man machine

interface.

LCN DESCRIPTION

Each of these nodes has a separate address and is

configured to this address through the use of these

jumper plugs (pinning) at the time of installation.

Each of the Hardware Module (nodes) attached to the

LCN have some common functionality, consisting of

an LCN interface mechanism, a processor and

memory. This common functionality is often referred

to as the “kernel”.

An LCN node takes from when distinct hardware is

added to its Kernel or common logic. A specific

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purpose board such as diskette controller, video

generator, special hardware board, etc. bring a

personality with it to the LCN hardware module. In

addition, the node is loaded with a unique software

package, written specially for that application. The

combination of common hardware, special hardware

and specially designed software combine to form the

node’s specialized personality.

The LCN network consists of two redundant coax

cables that run continuously from node to node (in a

bus topology). Each cable is connected to each

node’s LCN interface circuits with a T-connector. One

cable is marked CABLE A and the other is marked

CABLE B.

Both redundant cables are connected to each node.

Each node has specific connection for both A and B

cable and they must not be crossed. Terminators are

used on the ends of both cable A and B. The over all

length of each LCN cable segment should be kept

nearly equal to its redundant companion with a

maximum length of 300 meters and maximum load

of 40 physical connections for each LCN cable. Fiber

optics can be used to exceed some limitations.

LCN COMMUNICATION PROTOCOL

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The LCN communication Protocol is broadcast type of local

area network. Modules “talk”(broadcast) on both the A

and B cables simultaneously, but they “listen”(receive) on

only one cable. All LCN modules hear all transmission but,

depending on message destination and type, only some

modules process certain messages.

A token passing algorithm is used so that up to 64

modules can share access to the LCN. The communication

master node defines (to other nodes) which cable should

be used for listening. The communication master node is

the Universal Station (US) with the lowest LCN address; it

periodically issues an instruction to switch cables. This

ensures that both cables remain functional.

If any node experiences difficulty in

receiving data on a specific cable, it switches cables and

informs the communication master. The communication

master then informs all the other nodes to switch to the

good cable and dispatches a message to the system

maintenance control center (SMCC) requesting

maintenance on the suspect cable. This allows operation

to continue while the faulty cable is being repaired.

TOKEN PASSING

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Following figures illustrate a sample LCN arrangement

where token passing has been established between

several nodes. The number inside the “ring” in the figure

represents the node address of the modules on an LCN.

Remember, the “ring” is imaginary; the physical nodes

are really in a “string” with the actual node addresses

arranged in random order.

LCN OVERVIEW

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TOKEN PASSING SYSTEM

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AVANCED PROCESS MANAGER (APM)

It is an advanced data acquisition and control device used

for regulatory, logic and sequence control operation

required for continuous or batch applications. It consists of

a redundant advanced process manager module (APMM)

and maximum 40 input out put processors (IOP).

The advanced process manager (APM) is

Honeywell premier TDC 3000 data acquisition and control

device for industrial control applications.

Like the process manager (PM), the advanced

process manager new technology platform offers a range

of capabilities that best meet today and tomorrow’s

process requirements. The ASPM offer highly flexible I/O

functions for both data monitoring and control. Power

control functions, including regularity, logic and

sequencing control for provided for continuous, batch or

hybrid applications. An optical toolbox of functions that

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can be configured and programmed meets the needs of

data acquisition and advance control requirements in a

highly secure and performance intensive manner. Of

course, Amp’s capabilities include peer-to-peer

communication and compatibility with industry standard

protocols. As seen in the figure the advanced process

manager is a fully integrated member of the TDC 3000

family.

ACCORDINGLY APM IS CAPABLE OF: -

Performing data acquisition and control functions,

including regularity, logic and sequential control

functions, as well as per to peer communications

with other universal control network-reside4nt

devices.

Providing bi-directional communication to modbus

and ALLEN –BRADLEY COMPATIBLE subsystems

through a serial interface.

Fully communicating with operators and engineers at

universal station and universal workstations.

Procedures and displays are identical or similar to

those used with other TDC3000 controllers. Plant

personnel may already be familiar with them.

Supporting higher-level control strategies available

on the Local Control Network through the application

module and host computer.

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ADVANCED FEATURES: -

As described above, the Advanced Process Manager (APM)

has the same functionality that of the process manager

(PM) plus:

Digital input sequence of events (DISOE) processing.

Device control points.

Array point for CL programs.

Foreign device (serial) interface capability.

Larger memory (over four times larger than the PM).

String variables.

Time variable.

FUNCTIONAL DESCRIPTION: -

The advanced process manager is designed to provide

flexible and powerful process scanning and control

capabilities .To do this, it uses advanced multiprocessor

architecture with separate microprocessor dedicated to

perform specific tasks. The APM consist of the advanced

process manager module (APMM) and the I/O subsystem.

The advanced process manger module consists of an

advanced communication processor and modem,

advanced I/O link interface processor and advanced

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control processor, a redundant APMM can be optionally

provided.

The advanced communication processor is

optimized to provide high performance network

communications. Handling such functions as network data

access and peer-to-peer communication, it also supports

high accuracy time samps.

NETWORK INTERFACE MODULE (NIM)

The network interface module (NIM) provides the link

between the LOCAL CONTROL NETWORK and the

UNIVERSAL CONTROL NETWORK. Accordingly it makes the

transition from the transmission technique and protocol of

the local control network to the transmission technique

and protocol of the universal control network.

The NIM provides the LCN module access to

data from UCN resident device. It support program and

database loads to the advanced process manager and

forward alarms and message from the network device to

the LCN. The NIM is also available in the redundant

96

configuration to provide automatic continued operation in

the event of primary failure.

LCN time and UCN time are synchronized by

the NIM. The NIM broadcast LCN time over the UCN. The

APM uses it for all alarms (or events) time stampings.

LOGIC MANAGER (LM)

The logic manager (LM) is a process-connected device

that resides on the TDC 3000 Universal Control Network

as a peer to the process manager. The LM consists of a

standard Honeywell Logic Controller (LC) that contains a

two-slot option module known as Logic Manager Module

(LMM) and is mounted in one or more standard TDC3000

cabinets.

The main features of Logic manager are:

1. Direct peer-to-peer communication with other UCN

devices.

97

2. Communication with operator, engineer and

maintenance technicians at the universal station.

3. Support of higher-level control strategies through

communication with AM.

4. Database saving and restoration from the HM.

The logic manager (LM) is implemented for the application

requiring fast logic program execution, extensive digital or

interlock logic and ease of ladder programming.

LOGIC MANAGER OVERVIEW: -

98

As shown in the figure the Honeywell 620 Logic Controller

uses two basic types of racks. These are: -

Processor Rack

I/O Rack

Logic Manger (LM) consists of a Honeywell 620-35 PLC

processor rack with Logic Manager Module (LMM), Parallel

and Serial I/O racks and an MS-DOS Loader Terminal. The

LMM serves as an interface between the 620-35 processor

racks and the UCN. It converts the PLC data into UCN

format and vice versa.

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The MS-DOS loader terminal is an IBM compatible PC,

which serves as a man machine interface and is used for

graphic display and ladder programming. The

communication between the PC and processor take place

using an interface board and a serial cabinet shipped with

620-35 PLC.

The LM processor subsystem consists of a

standard Honeywell 620-35 processors rack plus a two

slot optional module known as Logic Manger Module

(LMM), used for UCN connectivity. The subsystem

hardware includes the chassis, back plane, and front

plates. The processor module is vertically positioned in

the racks with the component side towards left. Back

plane connector is offset to prevent inserting a module

upside down. The rack fits into an 8” NEMA 12 enclosure

or 19” instrumentation rack with 14 slots to insert

modules.

The LM processor rack has 14 slots from

A to N where different optional or standard modules could

be inserted.

THE DIFFERENT LM PROCESSOR RACKS ARE:

Processor Module (PM)-slot H

System control Module (SCM)-slot G

Register Module (RM)-slot F

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Memory Module –slot E

Input/output Control Module (IOCM)-slot I

Power Supply Module (PSM)-slot J&K

Parallel link Drive Module (PLDM)-slot N

Serial Link Module (SLM)-slot L & M

Logic Manger Module (LMM)-slot A &B

Redundancy Control Module (RCM)-slot C

Addition 8Kword Memory Module

REDUNDANCY SYSTEM

The LM redundant control system consists of two identical

configured processors, each containing a redundancy

control module (RCM). One processor is LEAD processor

and the other is the BACKUP processor. The system permit

sharing of data between the two redundant processor by

transferring I/O status cable, register table and system

status table. In the event of failure the control of I/O is

transferred from the LEAD processor to the back up

processor.

REDUNDANCY CONTROL MODULE

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It is a primary component of a LM redundancy control

system. It is responsible for:

Transferring I/O status table, Data register table and

system status table information from the LEAD to

BACKUP processor.

Monitoring the status of other RCM and its own host

processor.

Switching the control from LEAD to BACKUP

processor in the event of hardware failure of LEAD

processor or the user request.

SERIAL LINK SELECTOR

This is general purpose switching device, which may be

used, for connecting MS-DOS loader terminal to the two

processors.

REDUNDANT SIOM

In LM redundant system this module is used instead of

normal SIOM. It has two ports to which the serial I/O

cables coming from the two processors are connected. It

also has the RUN/FREEZE toggle switch. When the switch

is in:

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RUN position normal communication between SLM

and serial I/O track is permitted

FREEZE position all real I/O is freezing and

communication between SLM and serial I/O rack is

halted.

OVERVIEW OF REDUNDANCY SYSTEM

103

OPERATION OF REDUNDANCY CONTROL

SYSTEM

Consider a LM redundancy processor system with two

processor viz. A and B. suppose initially processor A is in

lead status and processor B is in the backup status. In the

two processor same ladder program is stored and before

every program scan processor A updates the I/O status

and register data in the processor B. thus even though

both the processor share the same program and data but

actual controlling is done by processor A. a backup

processor can be requested to take over the control of the

104

system either automatically (when lead processor fails) or

manually (by pressing the lead request switch). When the

RCM of the back up processor (in above case it is

processor B) grants the lead request it take following

action:

It informs the RCM of processor A that it is taking over

the control of the system.

It commands PBS to transfer all PBS to transfer all

parallel I/O operation to it instead of processor A.

It commands SLS to transfer all serial I/O operation to it

instead of processor A.

Turns on the LEAD status LED on the front plate.

The RCM of the processor A, in turn relinquishes the

control of serial and parallel I/O racks and turns off the

LEAD status LED. Now the processor B act as a lead

processor and processor A act as a backup processor in

the PLC system. Normally the manually lead request is

done while updating the control program. Thus there is no

disturbance in the process operation while a program

upgrading is being done. After the fault is recovered or

when a new program is down loaded the user can again

put processor A in lead position using above method. A

step by step method of online program down loading

making use of redundancy is as follows:

105

Consider above LM redundant processor system with

two processor viz. A and B with initially, say processor A

in lead status and processor in backup status and we

want to download a new program in the system. Ensure

that both the processors are online. That is they are

either in RUN or RUN/PROG mode.

Press led request switch on the RCM of processor B and

wait till the LEAD status indicator becomes on. Now

processor B executes the control program and the

program A is backup status.

Put processor A in PROGRAM mode using the mode key

switch on its PLDM.

Connect the MS-DOS loader terminal to processor A and

download the modified ladder program to it.

Put processor A in RUN or RUN/PROG mode using the

mode switch key on its PLDM.

Press led request switch on the RCM of the processor A

and wait till the lead status indicator becomes on. Now

the new control program start execution and the

processor B goes in backup state.

If the new program is not working properly then repeat

steps 2 to 6.

Put processor B in PROGRAM mode so that the new

program gets downloaded in the processor B from A via

106

data cable. Wait till PORT ACTV indicator on the both

RCMs is on and after that put processor B back in RUN

or RUN/ROG mode.

INDUSTRIAL TRAINING REPORT

Doing at

GURU HARGOBIND THERMAL PLANTLEHRA MOHABATTDISTT. BATHINDA

In

The Partial Fulfillment For The Requirement OfAward of DEGREE

InElectronics&communication

107

SUBMITTED TO : H.O.D.

ELECTRONICS&COMMUNICATIONS.U.S.C.E.T.TANGORI

MOHALI

SUBMITTED BY:INDER VERSHA

E.C.E-FINAL YEARROLL NO. 9901744

ACKNOWLEDGEMENT

Industrial training is the effort to provide linkage between the student and Industry in order to develop the awareness of industrial approach for saving the problem based on broad understanding of tools, modes of operation of Industrial Organization.

With the deep sense of gratitude, I express my sincere thanks to PSEB, Patiala, who permitted me to take up training at the Organization. I wish to extend my thanks to Er. M.S.Thind (S.E./C&I), Er.A.K.Chugh (Add. S.E.), Er.K.K.Jain (Add.S.E)&Er. Chhabra (Add.S.E) for their considerable help to join the training in different sections of C&I department. I humbly express my cordial thanks to Mr. Parveen Jain (A.E), Mr. AjitPal Singh (A.E), Mr. Dhiraj Bansal (A.E) and Mr. S.k.Sharma (A.E) for their extra pain to see me through my problems. They have been always a source of encouragement and inspiration for me. Under their efficient guidance, I had no problem in acquiring and getting various jobs done. I am always thankful to staff of industry for their kind cooperation and help, which made me training a success.

I feel that information gathered by me during this training will surely help me a lot in coming future.

108

ABSTRACT

My industrial training of six months of seventh semester of

B.Tech. Electronics&communication

As planned by Punjab technical university is organized in the Thermal Power Generation Plant at Lehra Mohabbat Distt. Bathinda.

My training of six months is divided in

three departments of control&instrumentation

each of two months. This report contains overall

plant circuit &department wise description.

INDERVE

RSHA

I

109

110

CONTENTS

1. INTRODUCTION2. WORKING OF THERMAL PLANT

3. SYSTEM DESCRIPTION 4. TDC 3000 5. UNIVERSAL STATION 6. TOTAL PLANT SOLUTION 7. REDUNDANCY SYSTEM

111

INTRODUCTION

BRIEF HISTORY OF PLANT

PROFILE OF PLANT

POWER DISTRIBUTION

RAW METERIAL &THEIR SOURCES

BASICS OF THERMAL PLANT

RANKINE CYCLE ON TEMPRATURE ENTROPY

DIAGRAM

PROCESS OF POWER GENERATION

PLANT OVERVIEW

BLOCKS DISCRIPTION

VARIOUS CYCLES INVOLVED IN POWER

GENERATION

112

113

SYSTEM DISCRIPTION

COAL HANDLINGSYSTEM FUEL OIL SYSTEM ASH HANDLING SYSTEM D.M.PLANT EMERGENCY POWER SUPPLY SYSTEM CONTROL&INSTRUMENTATION SYSTEM DATA ACQUISATION SYSTEM POWER SUPPLY DISTRIBUTION SYSTEM

TDC 3000 SYSTEM

AREA UNIT POINT CONCEPT

DISTRIBUTED CONTROL SYSTEM FUNTIONS DISTRIBUTED AROUND DCS

114

BENEFITS OF DCS

TDC ARCHITECTURE

TDC 3000 PROCESS OPERATIONS

UNIVERSAL STATION

DIFFERENT PERIPHERIAL CONNECTED TO U.S.

UNIVERSAL STATION PERSONALITY

LOADING OF U.S

115

U.S OPERATIONAL SECURITY

TDC OPERATOR CONSOLES

OPERATOR’S KEYBOARD

DESCRIPTION OF STANDARD OPERATION

FUNTION KEYS

TOTAL PLANT SOLUTION

1. OVERVIEW OF TPS

2. MAJOR COMPONENTS OF TPS

LOCAL CONTROL NETWORK (LCN)

DESCRIPTION

LCN COMMUNICATION PROTOCOL

116

TOKEN PASSING

OVERVIEW OF LCN

ADVANCE PROCESS MANAGER (APM)

CAPABILITIES OF APM

ADVANCE FEATURES

FUNCTIONAL DESCRIPTION

NETWORK INTERFACE MODULE (NIM)

LOGIC MANAGER (LM)

OVERVIEW OF LM

DIFFERENT LM PROCESSOR RACKS

REDUNDANCY SYSTEM

REDUNDANCY CONTROL MODULE

SERIAL LINK SELECTOR

REDUNDANT SIOM

OVERVIEW OF REDUNDANCY SYSTEM

117

OPERATION OF REDUNDANCY CONTROL

SYSTEM

118