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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
8
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
14
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
16
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
18
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)
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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.
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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).
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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.
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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).
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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.
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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
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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.
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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:
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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.
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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.
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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:
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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.
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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
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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.
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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