Download practical no.1 - Shankersinh Vaghela Bapu Institute of Technology

SHANKERSINH VAGHELA BAPU INSTITUTE OF TECHNOLOGY G’NAGAR
NAME OF SUBJECT:- ENERGY SYSTEM-140309
NAME OF FACULTY:- ANIL SHARMA, LOKIN JOSHI, NISHANT PARIKH
PRACTICAL NO. 1
Aim:- To STUDY OF STEAM
POWER STATION
NOTE:PRACTICAL SUBMISSION DATES FOR CV-II:B BATCH:- 20-1-2014 SIGN BY PROF. ANIL SHARMA
C BATCH:- 21-1-2014 SIGN BY PROF. ANIL SHARMA
A BATCH:- 24-1-2014 SIGN BY PROF. LOKIN JOSHI
PRACTICAL SUBMISSION DATES FOR CV-I:A BATCH-23-1-2014 SIGN BY PROF. ANIL SHARMA
C BATCH -21-1-2014 SIGN BY PROF. LOKIN JOSHI
B BATCH- 20-1-2014 SIGN BY PROF. NISHANT PARIKH
PRACTICAL SUBMISSION DATES FOR EC:A BATCH-24-1-2014 SIGN BY PROF. NISHANT PARIKH
C BATCH -21-1-2014 SIGN BY PROF. NISHANT PARIKH
B BATCH- 23-1-2014 SIGN BY PROF. NISHANT PARIKH
INSTRUCTION REGARDING PRACTICAL FILE PAGES:-
FILE PAGE YOU CAN USE IS DOUBLE SIDE OR SINGLE SIDE BUT IT MUST BE SAME
THROUGHOUT THE SEMESTER FOR ES PRACTICALS. ALL FIGURE MUST BE FAIR.
IF YOU ARE NOT ABLE TO COME ON DATE OF SUBMISSION THAN U CAN INFORM ME
BY MAIL OR U CAN GIVE YOUR FILE TO OTHER STUDENT.
*** DO NOT DRAW THIS FIGURE IN FILE
A thermal power station is a power plant in which the prime mover is steam driven. Water is heated, turns into
steam and spins a steam turbine which either drives an electrical generator or does some other work, like ship
propulsion. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was
heated; this is known as a Rankin cycle. The greatest variation in the design of thermal power stations is due to the
different fuel sources. Some prefer to use the term energy center because such facilities convert forms of heat energy
into electrical energy.
History
Reciprocating steam engines have been used for mechanical power sources since the 18th Century, with notable
improvements being made by James Watt. The very first commercial central electrical generating stations in New
York and London, in 1882, also used reciprocating steam engines. As generator sizes increased, eventually turbines
took over due to higher efficiency and lower cost of construction. By the 1920s any central station larger than a few
thousand kilowatts would use a turbine prime mover.
SCHEMATIC ARRANGEMENT OF STEAM POWER
STATION
(Schematic arrangement of steam power plant)
Fuel and Ash Circuit
Coal is delivered from the supply points to the storage site by road, rail or water. By road coal is transported in trucks
and for small stations such inland transport may be enough. Where power plants are situated close to a water way,
such as a canal, river or sea transportation by boat or ship may be quit effective. However, in most cases
transportation of coal by rail, road is the most common. In the case of small power plants the quantity of coal being
small, manual unloading from rail car may be used but for large power stations the unloading from the railway siding
is done with the help of wagon tipplers and then the coal is conveyed to the coal handling plant. From the coal
handling plant, the coal having been good enough to be burnt into boilers is taken into the boiler bunkers by means of
bucket conveyers. The coal is thus stored in the bunkers from where falling directly on the grate, or where the coal
spreaders are provided, coal is spread in the remaining galls at the rear end of the grate. Any unburnt coal particles in
the middle of the types
of boilers, where use of spreaders is made move from rear end to front end, and without spreaders, the movement of
the grate is from front end to rear end. Combustion is controlled ash resulting after complete combustion of fuel
collects at the back of the boiler and is removed to the ash storage by means of scrap conveyors.
(Process of Coal to Ash)
Air and Flue Gas Circuit
Air is drawn from the atmosphere by a forced draught fan or induced draught fan through the air pre-heater, in which
it is heated by the heat of flue gases passing to chimney and then admitted to the furnaces. The flue-gases after
passing around boiler tubes and super heater tubes are drawn by the induced draught fan through duct collector (or
precipitator), economizer and air pre-heater and finally exhausted to the atmosphere through chimney.
(Air and Flue gas circuit)
Feed Water and Steam Circuit
The steam coming out of the turbine is condensed and the condensate is extracted from the condenser by the
condensate extraction pump and is forced to the low pressure feed water heaters (usually three in numbers) where its
temperature is raised by the heat from bled steam (steam extracted from the lowest pressure extraction point of the
turbine). The feed water is now pumped through dearator to high pressure feed water heaters (usually 2 or 3 in
numbers) where it gets heated but the heat from bled steam extracted at suitable pint of the steam turbine. The
function of dearator is to reduce dissolved oxygen content in the condensate (i.e. in the feed water). The feed water is
then pumped into boiler through economizer in which it is further heated by the heat of flue gas passing through it on
the way to chimney. A small part (about 1 per cent) of steam and water in passing through the different components
of the system is lost. Therefore, water is added in the feed water system as make-up water, as shown in fig. In boiler
water is converted into high pressure steam, which is wet. Wet steam is passed through super-heater, where it is dried
and further superheated, and then supplied to the steam turbine through the main valve. After giving out its heat
energy to the turbine it is exhausted to the or more stages a quantity of steam is bled or withdrawn for heating og geed
water. Making up water for boiler is taken through the evaporator, where it is heated by low pressure steam extracted
at suitable point of turbine.
(Feed water and Steam circuit)
Cooling Water Circuit
Cooling water is supplied from a natural source of supply such as river, canal, sea or lake or cooling towers through
screens to remove the dry that steam and finally discharged to the suitable position near the source of supply. During
the passage its temperature rises and in the case of cooling towers the heat must be extracted before the water is again
pumped to the condenser. The circulation of cooling water to the condenser helps in maintaining a low pressure in
condenser.
(When there is enough water in river)
Choice of Site for Steam Power Stations
Choice of Site for Steam Power Stations Choice of Site for Steam Power Stations Choice of Site for Steam
Power Stations Choice of Site for Steam Power Stations. In order to achieve overall economy, the following
points should be considered while selecting a site for a steam power station:
1.
SUPPLY OF FUEL (AVAILIBITY OF RAW MATERIAL)
2.
AVAILABILITY OF WATER
3.
TRANSPORTATION FACILITIES
4.
NATURE OF LAND & ITS COST
5.
LOAD CENTRES
6.
DISTANCE FROM POPULATED AREA
7.
AVAILABILITY OF LABOUR
8.
FUTURE EXPANSION
9.
ASH DISPOSAL FACILITIES
10.
POLLUTION
11.
AWAY FROM AIR FIELDS
CONCLUSION:
It is clear that all the above factors cannot be favorable at one place. However, keeping in view the fact that
now-a-days the supply system is A.C. and more importance is being given to generation than transmission, a site
away from the towns may be selected. In particular, a site by river side where sufficient water is available, no
pollution of atmosphere occurs and fuel can be transported economically, may perhaps be an ideal choice
EQUIPMENT OF STEAM POWER PLANT
MOST IMPORTANT EQUIPMENTS OF PLANT ARE LISTED BELOW
1. Steam generating equipment
2. Condenser
3. Prime mover
4. Water treatment plant
5. Electrical equipment
Now we will study in detail on this equipment
1. Steam generating equipment
Its very important part of steam plant. Its includes boiler, boiler furnace, super heater, economizer, airpreheater
and other heat devices.
*** DO NOT DRAW THIS FIGURE IN FILE
i> Boiler:
boiler is closed vessel in which water is converted into steam by utilizing heat of coal combustion. Boiler
classified broadly into 2 parts
a> Water tube boiler: In water tube boiler water flow through the tubes and hot gases of combustion surrounds
it. It has number of advantages over fire tubes are required space is less, smaller in size of tubes and drums, high
working pressure due to small drum, less liable to explosion etc. Due to these reasons this type of boiler mostly
used for large capacity boiler at worldwide.
b> Fire tube boiler: in fire tube boiler hot gases of combustion passes through tubes and water surround it.
ii>Boiler Furnace:
it’s a chamber in which fuel is burnt to liable the heat energy also provide support and enclosure for combustion
equipment.
Boiler furnace walls are made of refractory materials like fire clay, silica, kaolin etc. these material resist to
change in shape, weight, physical properties at high temperature..
The construction of furnace walls is mostly 3 types
a> plain refractory wall: its suitable for small plants where temperature is low
b> Hollow refractory wall’s with an arrangement for air cooling: it is used to keep temperature of furnace
wall low by circulate air through hollow space.
c> Water walls: recently this type of construction is used in which water is used for cooling to air.
Note: the tubes are connected to upper and lower headers of the boiler. The boiler water is made to circulate
through the tubes. The water walls absorb the radiant heat in the furnace which would otherwise heat up the
furnace walls.
iii> Super heater: Main function of superheats the steam< it raise the temperature of steam above boiling
point of water. This increases overall efficiency of plant. It consist of group of tubes made of specially alloy steels
such as chromium-molybdenum. It is mainly classified into 2 parts.
a> Radiant super heater: its placed between water walls and receive heat from the burning fuel through
radiation process. These has 2 mail disadvantages which are:
 it may get overheated due to higher temperature into the boiler so required a careful design.
 Temperature of super heater falls with increase in steam output.
b> Convection super heater: it’s placed in boiler tube bank and receive s heat from flue gases entirely trough
the convection process. Only for this reason it is widely used.
iv> Economiser: it is a device which heats the feed water on its way to boiler by deriving heat from the flue
gases. Results increase the efficiency of the plant, by saving fuel and reduce stress in to boiler due to higher
temperature of feed water. Economiser consists of large number of closely spaced parallel steel tubes connected
by headers of drums. Feed water flow through these tubes.
v> Airpreheater: Super heater and economizer can’t fully extract the heat from flue gases so we employ
airpreheater. This increase the efficiency of plant. Airpreheater can be classified on 2 types on the method of
transfer of heat from flue gases to air.
a> Recuperative type: it consist group of steel tubes. The flue gases are transferred to air.
b> Regenerative type: it consists of slowly moving drum made of corrugated metal plates. The flue gases
continuously on one side of the drum and sir on the other side. This action permits heat transfer.
2. Condenser:
Its device which condenses heat at the exhaust of turbine. It perform mainly 2 function which are it creates a very
low pressure ay the exhausted of turbine, thus permitting expansion of the steam in the prime mover and
condensed steam can be used as feed water to the boiler. It has 2 types of condenser
a> Jet condenser: in this cooling water are mixed with exhausted steam, so the temperature os the same at the
time of leaving. Advantages of this type are low initial cost, less floor area are required, less cooling water
required and low maintenance charges.
b> Surface condenser:
There is no direct contact between water and steam. It consists of bank of horizontal tubes enclosed in a cast iron
shell. The steam gives up its heat to water is itself condensed. Advantages are condensed can be used as feed water,
less pumping power required and creation of better vacuum at the turbine exhaust. Disadvantages are higher initial
cost, required large floor area and high maintenance charges.
3. Prime Movers:
The prime movers convert steam energy into mechanical energy. Mainly 2 types of steam prime movers are steam
engine and steam turbines. A Steam turbine has several advantage over steam engine which are high efficiency,
simple construction, higher speed, less floor area required, low maintenance cost.
Steam turbine is generally classified into 2 parts according to the action on moving blades. Impulse and reaction
turbine.
a> Impulse turbine: steam expands completely in the fixed blades the pressure over the moving blades
remaining constant. In this mainly steam attains a high velocity and impinges against the moving blades,
which improves impulse force ion the blades which set the rotor rotating.
b> Reaction turbine: steam is partially expanded in the fixed blades; the remaining expansion takes place during
its flow over the moving blades.
4. Water Treatment Plant:
Boiler required clean and soft water for longer life and better efficiency. Mainly source of water is river, lake
which contains suspended and dissolved impurities, dissolved gases etc. water were purified and soft by chemical
treatment than delivered to the boiler.
The suspended impurities are removed through sedimentation, coagulation and filtration.
Dissolved gases are removed by aeration and degasification. The water is then softened by removing temporary
and permanent hardness through different chemical processes.
5. Electrical Equipment:
i> Alternators: it converts the mechanical energy into electrical energy. It may be hydrogen or air cooled.
Necessary excitation provided by exciter and pilot exciter by direct coupled to the alternator shaft.
ii> Transformer: generating station has different types of transformer,
a> Mainly step-up which step-up the generation voltages.
b> Station transformer which are general used for general services like lightning in power station.
c> Auxiliary transformer which supply to individual unit-auxiliaries.
iii> Switchgear: it houses such equipment which locates the fault on the system and isolate the faulty part from
the healthy section. It contains circuit breaker, relays, switches and other control devices.
ADVANTAGES OF TPS (THERMAL POWER STATION)
1. Used fuel is very cheaper.
2. It can handle change in load very quickly.
3. Space required for plant is less to hydro.
4. Steam can be used in various industries.
5. Overloaded up to 20%.
6. Initial and power generation Cost is less to diesel plants.
7. Located near the load so transmission Line cost and Losses reduces.
DISADVANTAGES OF TPS
1. Cost of Operation & Maintenance is high.
2. Required time for Errection is more before the operation of plant.
3. Water requirement is higher.
4. Handling of coal & ash is major problem.
5. Efficiency of plant is low.
6. Health problem because of pollution to workers and nearby area person are major.
NOTE FOR STUDENTS:---STUDENTS HAVE TO WRITE UPTO ABOVE THEORY ONLY.
THE BELOW LIST OF QUESTION WILL BE ASK IN TEST WHICH WILL BE CONDUCTED IN
BETWEEN 20 TO 25TH JAN 2014 WEEK AS PER YOUR RESPECTIVE LAB SESSIONS.
LIST OF Questions of TPS FOR TEST IN LAB
1. Explain the function and location of following equipments with respect to thermal power plant
I-Super Heater
II-Electrostatic Precipitator
III-Economizer
IV-Condenser
V-I.D. Fan
VI-F.D. Fan
VII-Exciter
2. Draw typical layout of thermal power plant with help of schematic diagram.
(Or)
Explain schematic arrangement of steam power station with neat sketch.
3. Give Merit and Demerit of steam power station.
4. Discuss: choice of site selection for thermal power station.
(Or)
Discuss: Site selection for thermal power station.
5. Usually steam power plant operates on which kind of fuel?
ANS:
Solid fuel as coal
Liquid fuel as oil
Gaseous fuel as natural gas
7. Give the list of coal transportation methods used in thermal power plant
ANS:
By sea or river
By rail (when plant is far from mines)
By road (only used for small power plant)
By pipe line (most economical and easy method)
8. What are the requirements for coal handling plant at site?
ANS:
Minimum maintenance
Simple
Reliable
Continuous supply of coal as per demand of power plant
Minimum wear in running the equipment due to abrasive action of coal particles
9. Give the list of methods used for coal weighting in power plant.
ANS:
Mechanical
Pneumatic
Electronic
10. Which kind of precautions should be taken in coal storage in power plant?
ANS:
Place for coal storage should have proper drainage system
Coal is stored in compact piles which are not loose or porous
Conical piling is avoided
Piles are sealed with asphalt or fine coal
Firefighting equipment must be installed near the storage
11. Why we should do disposal of Ash from power plant.
ANS: Ash produced in central plant is about 10% to 20% of coal burnt /day; it’s necessary to provide some means
to remove this ash and disposed off at a sufficient distance from the site of power station for the following reason:
Ash is dust; hence it’s irritating and annoying to handle in general and particularly to eyes.
It forms clinkers by fusing together in large lumps which must be broken before given to any conveying
equipment.
Ash is hot when it comes out of the furnace so its quenching is necessary.
It produces corrosive acids when mixed with water.
11. Explain the Electrostatic Dust Collector OR Electrostatic Precipitator OR ESP.
ANS:
Commercial ESP was developed in 1937, used in many power plant used by steel, paper mills and other industries.
Basic elements of ESP are listed below,
High voltage source of 440V, 50Hz, 3 phase supply
2 set of electrodes insulated from each other called emitting and collecting electrodes
High voltage transfer
Rectifier to covert AC into DC
EXPLAINATION OF THE ESP:
-
Two set of electrodes INSULATED from each other
-
1st set has the row of electrically grounded vertical parallel plates called Collection electrodes.
-
2nd set of electrodes consists of wires called discharge or emitting electrodes, its carry the negatively charged
high voltage (40 to 80 kV) current from an external DC source.
-
Dust laden gas is passed between these two electrodes which are oppositely charged, this gas becomes
ionized as the high voltage of 40 to 80 kV is applied depending on the electrode spacing.
-
Both negative and positive ions are formed, positive iron travel to the negatively charged wire electrodes.
-
The electrons follow the electrical field towards the grounded electrodes but there velocity decreases as they
move away. Gas molecular capture the low velocity electrons and becomes negative irons. As these irons
move to the collecting electrodes, they collide with fly ash particles in the gas streams and give them negative
charged. The negatively charged fly ash is driven to the collecting plate by the electrostatics force and is
separated from the gas.
-
The use of these collectors is increasing due to strict pollution norms. Sometimes they are used in addition
with cyclone a collector if the size of dust particle is high of has high collection efficiency of the order of 90%
and above.
ADVANTAGES:
1. It can remove fine dust particle efficiently.
2. The maintenance charges are low.
3.
Easy to operates.
4. It is most effective with high dust loaded gas(100gm/m^3)
5. Dust is collected in dry form.
DISADVANTAGES:
1. Capital cost is high.
2. Operational charges are high.
3. Space requirement is more compare to other dust collectors.
4. If gas velocity above the design speed increases, its collection efficiency is reduced.
PLANNING FOR THERMAL POWER PLANT(FOR YOUR
REFERENCE ONLY NOT ASK IN TEST)

First unit of 800 MW to be commissioned in July 2011.

Will sell electricity to state-owned utilities in 5 states – Gujarat, Maharashtra, Haryana, Rajasthan and Punjab.

Project cost of US$4.2 billion to be financed by equity (US$1 billion) and debt from IFC (US$450 million), ADB (US$450 million),
Korean ECAs (US$800 million), local banks (US$1.5 billion).

India’s first private sector power project using supercritical technology; most energy efficient plant in the country.

Creation of 5,000 construction jobs and 700 jobs during operations.

Project site is sparsely vegetated with marginal cultivation; remotely situated from eco-sensitive spots; impacted coastal area devoid of
mangrove vegetation and coral reefs.
Adani Group are also in the process of setting up a 4620MW Thermal Power Plant at Mundra, this is due to be the Worlds 3rd largest
upon

completion
in
Thermal Power Current installed capacity of Thermal Power (as of 12/2008) is 93,392.64 MW which is 63.3% of total installed
capacity.
* Current installed base of Coal Based Thermal Power is 77,458.88 MW which comes to 53.3% of total installed base.
* Current installed base of Gas Based Thermal Power is 14,734.01 MW which is 10.5% of total installed base.
* Current installed base of Oil Based Thermal Power is 1,199.75 MW which is 0.9% of total installed base.
The state of Maharashtra is the largest producer of thermal power in the country
2012.
REFERANCES:
Retrieved from "http://en.wikipedia.org/wiki/Thermal_power_station"
GOOGLE SEARCH
BOOKS:
PRINCIPLE OF POWER SYSTEM: -J.B.GUPTA
PRINCIPLE OF POWER SYSTEM: -V.K.MEHTA
ENERGY SYSTEM:-B.L.SINGHAL