maharashtra state boarad of technical...

MAHARASHTRA STATE BOARAD OF

Subject Code: 12057

Important Instruction to examiners

1) The answers should be examined by key words and not as wordmodel answer scheme.

2) The model answer and the answer written by assess the understanding level of the candidate.

3) The language errors such as grammatical, spelling errors should not be given more importance.(Not applicable for subject English and Communication Skills)

4) While assessing figures, examiner may give credit for principle components indicated in a figure. The figures drawn by candidate and model answer may vary. The examiner may give credit for any equivalent figure drawn.

5) Credits may be given step wise for numericavalues may vary and there may be some difference in the candidate’s answers and model answer.

6) In case some questions answer based on candidate u

7) For programming language papers, credit may be given to any other program based on equivalent concept.

Q.1 Attempt any Ten of the following

a) List any four sources of conventional energy.

Following are the conventional energy sources.

1. Water or Hydro

2. Fuel used as a high grade coal,

3. Fuel used as a natural oil and gas

4. Fuel used as a diesel

5. Atomic or Nuclear Energy

1. Thermal power plant

2. Nuclear power plant

3. Hydro power plant

4. Diesel power plant

MAHARASHTRA STATE BOARAD OF TECHNICAL EDUCATIOD(Autonomous)

(ISO/IEC-27001-2005 Certified)

SUMMER – 13 EXAMINATION

Model Answer

to examiners:

The answers should be examined by key words and not as word-to

The model answer and the answer written by candidate may vary but the examiner may try to assess the understanding level of the candidate. The language errors such as grammatical, spelling errors should not be given more

(Not applicable for subject English and Communication Skills)assessing figures, examiner may give credit for principle components indicated in a

figure. The figures drawn by candidate and model answer may vary. The examiner may give credit for any equivalent figure drawn. Credits may be given step wise for numerical problems. In some cases, the assumed constant values may vary and there may be some difference in the candidate’s answers and model

credit may be given by judgment on part of examiner candidate understands.

For programming language papers, credit may be given to any other program based on

of the following

List any four sources of conventional energy.

conventional energy sources.

high grade coal,

oil and gas

Atomic or Nuclear Energy

OR

TECHNICAL EDUCATIOD

Page No: 1 of 33

to-word as given in the

candidate may vary but the examiner may try to

The language errors such as grammatical, spelling errors should not be given more (Not applicable for subject English and Communication Skills)

assessing figures, examiner may give credit for principle components indicated in a figure. The figures drawn by candidate and model answer may vary. The examiner may give

l problems. In some cases, the assumed constant values may vary and there may be some difference in the candidate’s answers and model

on part of examiner of relevant

For programming language papers, credit may be given to any other program based on

20 Marks


Subject Code: 12057

b) List any two hydroelectrical power stations in Maharashtra with their installed capacity.

Hydro-electric power stations in Maharashtra:

consider while giving mark.

S.No Location

1 Koyana 2 Mulshi Dam 3 Jayakwadi 4 Chadholi(Warana5 Paithon/Ujjani 6 Bhira Tail Race 7 Veer 8 Bhatghar 9 Vaitarana Dam 10 Tillari 11 Eldary 12 Radhanagri 13 Paitan 14 Pawan 15 Panshet 16 Varasgoan 17 Kanher 18 Bhatsa 19 Dhom 20 Manikdoh 21 Yeoteshwar 22 Dimbhe 23 Surya 24 Surya R.B 25 Terwabnedhe 26 Dudhgaon 27 Bhandara 28 Pench project 29 Bhivapuri (TATA)30 Khopoli (TATA) 31 Bhira (TATA)




Model Answer

List any two hydroelectrical power stations in Maharashtra with their installed capacity.

electric power stations in Maharashtra:- Student may write different location may be

consider while giving mark. (Any two of the following expected

Location Capacity

1960MW 150MW 12 MW

na) 16MW 12 MW 80 MW 9 MW 16 MW 1.5 MW 60 MW

22.5 MW 4.8 MW 12 MW 10 MW 8 MW 8 MW 4 MW 15 MW 2 MW 6 MW

0.075 MW 5 MW 6 MW

0.75 MW 0.2 MW 24 MW 34 MW 53 MW

Bhivapuri (TATA) 72 MW 72 MW

150 MW

TECHNICAL EDUCATIOD

Page No: 2 of 33

List any two hydroelectrical power stations in Maharashtra with their installed capacity.

Student may write different location may be

(Any two of the following expected -1 mark for each)


Subject Code: 12057

c) State the function of chimney and

1. Function of Chimney:

Flue gases (smoke) are produced during combustion process. These flue gases

produce air pollution, SO to reduce air pollution it should be passed in air as high as

possible with the help of Chimney.

2. Function of Super heater

Its function is to remove the moisture from the steam leaving the boiler and also to

increase its temperature above the saturation temperature.

For this purpose heat energy of exhausted flue gases from the furnace is utilized.

d) State the main components o

Main Components of Nuclear power Plant:

i) Nuclear Reactor

ii) Heat exchanger

iii) Coolant circulating System

iv) Condenser Plant

v) Steam value

vi) Steam Turbine

vii) Alternator

e) Give Classification of diesel engines.

Classification of Diesel Engines:

i) Two Stroke Diesel Engine

ii) Four Stroke Diesel Engine




Model Answer

State the function of chimney and superheater in thermal power station.

Function of Chimney: (Each Function 1 Mark)



possible with the help of Chimney.

Super heater:

is to remove the moisture from the steam leaving the boiler and also to

increase its temperature above the saturation temperature.


State the main components of Nuclear Power station.

(At least four component expected each component 1/2

Main Components of Nuclear power Plant:

Nuclear Reactor

Heat exchanger

Coolant circulating System

Condenser Plant

Give Classification of diesel engines.

Engines:

Two Stroke Diesel Engine

Four Stroke Diesel Engine

TECHNICAL EDUCATIOD

Page No: 3 of 33

superheater in thermal power station.

(Each Function 1 Mark)



is to remove the moisture from the steam leaving the boiler and also to


four component expected each component 1/2 Mark)

(Each Type 1 Mark)


Subject Code: 12057

f) List the major locations of wind mills in Maharashtra.

Locations of Wind Mills in Maharashtra

1/2 Mark) Student may write different location may be consider while giving mark.

S.No

1 2 3 4 5 6 7 8

g) State two important drawbacks of hydroelectric power stations.

Drawbacks expected each drawbacks

Important drawbacks of hydroelectric Power Stations

1. High capital cost due to construction of dam.

2. It depends on nature as it require huge amount of water which is store during rainy

season.

3. Firm power (Out put) is totally depends on monsoon.

4. It takes long time for complete e

5. It requires large area (catchment) area for

6. As sites are away from load centre, so cost of transmission and losses in it are more.

7. There is limitation to select the site of HPP because of their requirements.

h) Why the power stations are connected with each other.

Because of following advantages power stations are connected with each other:

i) Reduced Overall installed

Inter connected power systems reduce the overall requirement of installed capacity.

With interconnection between power systems, peak demand in an area is meet by importing




Model Answer

List the major locations of wind mills in Maharashtra.

s in Maharashtra: - (At least four location expected each location

may write different location may be consider while giving mark.

Location

Gudepaachgani (Sangli) Panchgani (Satara) Chalkewad (Satara) Thosghav (Satara) Kotoli (Kolhapur)

Devgad or Deogad (Sindudurga) Vankusawade (Near koyna)

Vashpet (Sangli)

State two important drawbacks of hydroelectric power stations.

Drawbacks expected each drawbacks 1 Mark)

Important drawbacks of hydroelectric Power Stations:- (Expected any two

High capital cost due to construction of dam.

It depends on nature as it require huge amount of water which is store during rainy

Firm power (Out put) is totally depends on monsoon.

It takes long time for complete erecting of power plant.

It requires large area (catchment) area for storage of water.

As sites are away from load centre, so cost of transmission and losses in it are more.

There is limitation to select the site of HPP because of their requirements.

the power stations are connected with each other.


(At least four points expected each point 1/2

i) Reduced Overall installed Capacity:-



TECHNICAL EDUCATIOD

Page No: 4 of 33

(2 Mark)

four location expected each location

may write different location may be consider while giving mark.

State two important drawbacks of hydroelectric power stations. (At least Two

(Expected any two 1 Marks each)

It depends on nature as it require huge amount of water which is store during rainy

As sites are away from load centre, so cost of transmission and losses in it are more.

There is limitation to select the site of HPP because of their requirements.

(2 Mark)


least four points expected each point 1/2 Mark)




Subject Code: 12057

power from neighboring area. Thus, it also reduces investment and

demand.

ii) Better Utilization Hydro Power:

In combined power system, hydro power can be utilized in more effective way.

during rainy season, hydro power plant can be utilized, while during draught per

power plant can be used as base load plant.

iii) Reliability of Supply:

The reliability of steam power plants depends upon the coal supply and that of hydro

power plant depends upon the stream flow. due to greater diversi

of various types of power plant is more reliable than individual power plant.

iv) High unit size possible:

Generating units of higher unit capacity (200MW, 500MW etc) can be installed and

operated economically.

v) Improved quality of voltage and frequency:

Isolated power systems have higher frequency fluctuations with change in load. With

inter connections, the system becomes stronger & the effect of load is reduced.

vi) Exchange of peak loads:

If the load curve of power station shows a peak demand that is greater than the rated

capacity of the plant, then the excess load can be shared by other stations connected with it.

vii) Use of older Plants:-

The interconnected system makes it possible to use older and less efficient plants to

carry peak loads of short durations. Although such plants may be inadequate when used

alone, yet they have sufficient capacity to carry short peaks up load

with other modern plants.

viii) Insure Economical operation:

The interconnected system makes the operation of concerned power station quite

economical. It is because sharing of loads among the stations is arr

more efficient plants work for peak load hours only.




Model Answer

from neighboring area. Thus, it also reduces investment and

ii) Better Utilization Hydro Power: -


season, hydro power plant can be utilized, while during draught per

can be used as base load plant.

Reliability of Supply: -


power plant depends upon the stream flow. due to greater diversity, a combined operation


iv) High unit size possible:-


ly.

Improved quality of voltage and frequency:-


connections, the system becomes stronger & the effect of load is reduced.

ak loads:-


plant, then the excess load can be shared by other stations connected with it.

-



have sufficient capacity to carry short peaks up load


Insure Economical operation:-


economical. It is because sharing of loads among the stations is arranged in such a way that


TECHNICAL EDUCATIOD

Page No: 5 of 33

from neighboring area. Thus, it also reduces investment and fulfills the peak


season, hydro power plant can be utilized, while during draught periods, steam


ty, a combined operation






plant, then the excess load can be shared by other stations connected with it.



have sufficient capacity to carry short peaks up load when inter-connected


anged in such a way that


Subject Code: 12057

ix) Increases Diversity factor:

The maximum demand on the system is reduced because load curves of different

inter-connected stations are differe

thereby increasing the effective capacity of the system.

x) Increases load factor:-

The load factor and efficiency of operation are improved.

xi) Reduces Plant Reserve

Every power station is required to have a standby unit for emergencies. However

when several power stations are connected in parallel, the reserve capacity of the system is

mush reduced. This increases efficiency of the sys

xii) Better utilization of natural resources:

Due to interconnection, there is optimum utilization of available natural resources

in the country is possible.

i) Define load factor. What is maximum value of load factor?

Load Factor:

The ratio average demand to the maximum demand during a given period is known as

load factor.

Maximum

FactorLoad =

FactorLoadYearly

Maximum value of load factor:

Maximum value of load factor is




Model Answer

Increases Diversity factor:-


connected stations are different. So, diversity factor of the system is improved,


-


Reduces Plant Reserve capacity:-


several power stations are connected in parallel, the reserve capacity of the system is

mush reduced. This increases efficiency of the system.

Better utilization of natural resources:



Define load factor. What is maximum value of load factor? (Each Definition 1 Mark)


demandMaximum

demandAverage OR

(1

)(.

yearinHoursdemandMaximum

oneingeneratedKWHunitsofNoFactor

×=

Maximum value of load factor:

Maximum value of load factor is one.

TECHNICAL EDUCATIOD

Page No: 6 of 33


nt. So, diversity factor of the system is improved,




(Each Definition 1 Mark)


)8760( hr

yearone


Subject Code: 12057

j) State the materials used for control rods in nuclear reactor. Mention the function of

control rod.

Material used for control rod should have

i) Boron

ii) Cadmium

iii) Hafnium

Function of Control Rod:

Fuction of contrl rod is to be regulate fission process by absorbing the

The control rod is inserted into the reactor core from top of the reactor vessel.

The function of control rod is to control the chain reaction in reactor core by

adjusting its height.

k) Define the overall efficiency of thermal

Overall Efficiency of Thermal power Station:

(Note: Student may write

Overall efficiency

Where, H= Heat equivalent per KWH

W = Amount o

Cv = Calorific value

l) What is the difference between cold reserve and hot reserve in connection with

generating station?

S.No Cold Reserve

1 It is standby generating capacity

which is available for service but

not in operation




Model Answer

State the materials used for control rods in nuclear reactor. Mention the function of

(Material used for control rod- 1 Mark & Function

Material used for control rod should have neutron absorbing properties:

Function of Control Rod:

Fuction of contrl rod is to be regulate fission process by absorbing the

The control rod is inserted into the reactor core from top of the reactor vessel.


Define the overall efficiency of thermal power station.

Overall Efficiency of Thermal power Station:-

(Note: Student may write definition in different way also)

verall efficiency VCW

H

.×=η

= Heat equivalent per KWH

of coal consumed per KWh

= Calorific value of fuel

What is the difference between cold reserve and hot reserve in connection with

(2 Mark)

Cold Reserve Hot ReserveIt is standby generating capacity

which is available for service but

not in operation

It is reserved generating

capacity, in operation but not

in service

TECHNICAL EDUCATIOD

Page No: 7 of 33

State the materials used for control rods in nuclear reactor. Mention the function of

1 Mark & Function -1 Mark)

absorbing properties:

Fuction of contrl rod is to be regulate fission process by absorbing the neutron.

The control rod is inserted into the reactor core from top of the reactor vessel. OR


(2 Mark)

different way also)

What is the difference between cold reserve and hot reserve in connection with

Mark)

Hot Reserve It is reserved generating

capacity, in operation but not


Subject Code: 12057

m) What is meant by lake tapping? State the name of power station with which it i

connected in Maharashtra State.

Lake Tapping:-

Lake tapping is a method of blasting an intake into a body of water from below

the natural water surface without first lowering that surface or installing a protective

cofferdam around the tap hole. Lake taps are done by first excavating a tunnel almost to the

water/rock contact and then blasting out the final protective rock plug at one time to allow

water to suddenly inflow into the tunnel from the lake. This procedure can be done "dr

"wet." In the dry method the tunnel is empty of water before the final plug blast while in

the wet method it is partially filled with water

Lake tapping is a method of blasting an intake into a body of water from

below the natural water surface without first lowering that surface or installing a protective


water/rock contact and then blasting out the final protective rock plug at one t

water to suddenly inflow into the tunnel from the lake

The name of power station with which it

Koyna Hydro power plant

Q.2 Attempt any Four of the following

a) Draw a typical layout of a thermal power plant and label it.




Model Answer

What is meant by lake tapping? State the name of power station with which it i

connected in Maharashtra State. (Lake Tapping-1 Mark & Name of P.P



the tap hole. Lake taps are done by first excavating a tunnel almost to the


water to suddenly inflow into the tunnel from the lake. This procedure can be done "dr


the wet method it is partially filled with water. OR


tural water surface without first lowering that surface or installing a protective


water/rock contact and then blasting out the final protective rock plug at one t

water to suddenly inflow into the tunnel from the lake

he name of power station with which it is connected in Maharashtra State:

Koyna Hydro power plant (Satara)

of the following

Draw a typical layout of a thermal power plant and label it.

TECHNICAL EDUCATIOD

Page No: 8 of 33

What is meant by lake tapping? State the name of power station with which it is

1 Mark & Name of P.P- 1 Mark)



the tap hole. Lake taps are done by first excavating a tunnel almost to the


water to suddenly inflow into the tunnel from the lake. This procedure can be done "dry" or



tural water surface without first lowering that surface or installing a protective



is connected in Maharashtra State:

16 Marks

(4 Mark)

or equivalent figure


Subject Code: 12057

b) State the factors affecting the site

brief.

Following points are considred while selecting site for thermal power sta

i) Distance from coal mines :

The power plant should be near the coal mine ,so that cost of fuel transportation

reduces.

ii) Availability of Water :

Sufficient quantity of water should be available because water is as good as

secondary fuel which is required for

So,plant should be located near river,

iii) Space availability :-

The power plant should have sufficient large space available for coal storage &

ash disposal.

iv) Load Centre :-

Plant should be located near load centre to reduce t

line losses.

v) Easy acces :-

The site should have easy acces for transportation

vi) Condition of soil:-

The land should be rock

and machianry.

vii) Distance from populated area:

It should be located at a resionable distance away from the populated area.Because

smoke & other hazards gases are produced

pollution.




Model Answer

State the factors affecting the site selection of thermal power station. Discuss these in

( Any four point expected

Following points are considred while selecting site for thermal power sta

Distance from coal mines :-


Availability of Water : -


fuel which is required for producing steam and for condensing plant.

o,plant should be located near river, water resevaior as far as possible.


Plant should be located near load centre to reduce transmission co

The site should have easy acces for transportation of machanery, man power, etc

The land should be rocky (Hard murrum) for the better foundation of building

Distance from populated area:-


smoke & other hazards gases are produced due to combusion of the coal which

TECHNICAL EDUCATIOD

Page No: 9 of 33

selection of thermal power station. Discuss these in

Any four point expected-1 Mark each point)

Following points are considred while selecting site for thermal power station :-



condensing plant.

r as possible.


ransmission cost & transmission

of machanery, man power, etc

(Hard murrum) for the better foundation of building


due to combusion of the coal which causes air


Subject Code: 12057

c) What is meant by quality of fuel in connection with thermal power station? State its effect

on quality of power generation.

(Note: Student may write

Quality of Fuel:

Quality of fuel means its calorific value that is how much heat energy is produced

from a given quantity of fuel.

Effect on quality of power generation

but,

� The use of coal with high ash content increases the plant size and transportation cost and

reduces the thermal efficiency.

� Fuel consumption increases.

� Steaming time increases.

� Efficiency of Furnace decreases.

d) Draw neat constructional diagram of Nuclear reactor. Label it. State working of it

briefly.

Working :

It is an appratus in which heat energy is produced due to nuclear fission chain

reaction. The energy libreted in the chain reaction is according to Einstein’s law and is given

by 2mcE = and it consists of following parts.

heat exchanger.




Model Answer

What is meant by quality of fuel in connection with thermal power station? State its effect

on quality of power generation. (Difination- 2 Marks & Effect

(Note: Student may write answer in different way also)


from a given quantity of fuel.

Effect on quality of power generation: - There is no effect on quality of power generation

The use of coal with high ash content increases the plant size and transportation cost and

reduces the thermal efficiency.

Fuel consumption increases.

Steaming time increases.

Furnace decreases.

Draw neat constructional diagram of Nuclear reactor. Label it. State working of it

(Digaram-2 Marks & Working

OR



consists of following parts. This heat energy is utilise for producing steam in

TECHNICAL EDUCATIOD

Page No: 10 of 33

What is meant by quality of fuel in connection with thermal power station? State its effect

2 Marks & Effect – 2 Mark)

different way also)


no effect on quality of power generation

The use of coal with high ash content increases the plant size and transportation cost and

Draw neat constructional diagram of Nuclear reactor. Label it. State working of it

2 Marks & Working – 2 Mark)




This heat energy is utilise for producing steam in


Subject Code: 12057

e) Define the terms nuclear fission and chain reaction as referred to nuclear power station.

Nuclear Fission:

Energy is released without using oxygen for combustion in process is known as

nuclear Fission.

Chain Reaction: (Note: Student may write

When nuclear fuel U235

under goes nuclear reaction at that time ;

� Huge amount of heat energy is liberated and

� Two or three neutron are produced

� γβα ,&,

� Beryllium & krypton are also produced.

Due to two or three neutron chain reaction is continuous till most of the original nuclei in

the given sample are fissioned is called as chain reaction.

f) State 3 Limitations of nuclear power st

Maharashtra with its installed capacity.

Limitations of nuclear power station:

i) The capital cost NPP is very high as compared to other same capacity.

ii) Fuel used is very expensive & is very difficult to recover.iii) The erecting and commissioning of plant requires greater technical knowledge.iv) It causes radioactive air pollution.v) Maintenance charges arevi) High salaries of special trained personnel employed to handle the plant.vii) Nuclear waste disposal cost is high and is a big problem.viii) The cooling water requirements of NPP are very heavy.ix) Cooling towers required for NPP are x) This plant is not suitable for variable load.

Name the nuclear power station in Maharashtra with its installed capacity:

i) Tarapur: Capacity: 420 MW




Model Answer

Define the terms nuclear fission and chain reaction as referred to nuclear power station.

(Each Difination


(Note: Student may write answer in different way also)

235 or Pu239 when strikes by a slow neutron in nuclear reactor than it

under goes nuclear reaction at that time ;

Huge amount of heat energy is liberated and

Two or three neutron are produced

γ rays are produced

Beryllium & krypton are also produced.


oned is called as chain reaction.

State 3 Limitations of nuclear power station. Name the nuclear power station in

Maharashtra with its installed capacity.(Limitation -3 Marks & Name of N.P.P

power station: (Any three Expected)

NPP is very high as compared to other conventional power plant of

Fuel used is very expensive & is very difficult to recover. The erecting and commissioning of plant requires greater technical knowledge.It causes radioactive air pollution.

charges are high because it requires high skill technician.High salaries of special trained personnel employed to handle the plant.Nuclear waste disposal cost is high and is a big problem. The cooling water requirements of NPP are very heavy. Cooling towers required for NPP are larger & costlier than TPP.This plant is not suitable for variable load.


Capacity: 420 MW

TECHNICAL EDUCATIOD

Page No: 11 of 33

Define the terms nuclear fission and chain reaction as referred to nuclear power station.

Each Difination-2 Marks)


different way also)

when strikes by a slow neutron in nuclear reactor than it


ation. Name the nuclear power station in

Marks & Name of N.P.P – 1 Mark)

conventional power plant of

The erecting and commissioning of plant requires greater technical knowledge.

requires high skill technician. High salaries of special trained personnel employed to handle the plant.

larger & costlier than TPP.



Subject Code: 12057


a) Classify hydroelectric power stations on basis of : i) Head water ii) Quantity of water

available

Hydro power plants are

i) Head of Water :

i) Low head power plant (Below 30m)

ii) Medium head power plant (30 to 300 m)

iii) High head power plant (above 300m)

ii) Quantity of water available :

i) Run-off River power plant without poundage

ii) Run-off river power plant with poundage

iii) Large reservoir power plant

b) Draw neat layout of hydro




Model Answer

of the following

Classify hydroelectric power stations on basis of : i) Head water ii) Quantity of water

(Each Classification

classified as below:

i) Low head power plant (Below 30m)

ii) Medium head power plant (30 to 300 m)

iii) High head power plant (above 300m)

available :-

off River power plant without poundage

off river power plant with poundage

iii) Large reservoir power plant

Draw neat layout of hydro-electric power station. Label it. Explain the operation briefly.

(Diagram- 2 Mark & Operation


TECHNICAL EDUCATIOD

Page No: 12 of 33

16 Marks

Classify hydroelectric power stations on basis of : i) Head water ii) Quantity of water

Classification – 2 Mark each)

Label it. Explain the operation briefly.

2 Mark & Operation -2Mark )


Subject Code: 12057

Operation of Hydro- Electric Power Plant:

Water stored at high level by constructing dam across river. This stored w

potential energy. This stored water is passed to run the water turbine which is located at

lower level through penstock.

Thus potential energy of water is converted into kinetic energy in penstock and

turbine converts kinetic energy

turbine which converts mechanical energy into electrical energy.

c) What are pumped storage plants? Draw a neat labelled sketch of pumped storage plant.

State its operation and application.

Application – 1 Mark)

Pumped storage hydroelectric power

� It consists of head water pond

� Tail water pond and head water

� Such plants can be operated only in

plants (such as TPP & NPP

� During peak hours the turbine drives the generator and generates elect




Model Answer

Electric Power Plant:

(Note: Student may write operation in

Water stored at high level by constructing dam across river. This stored w


lower level through penstock.


turbine converts kinetic energy into mechanical energy and Alternator is coupled to water

turbine which converts mechanical energy into electrical energy.

What are pumped storage plants? Draw a neat labelled sketch of pumped storage plant.

State its operation and application. (Digaram-2 Marks, Operation

umped storage hydroelectric power plant & Operation:-

head water pond (reservoir) and tail water pond by constructing a

Tail water pond and head water pond connected through penstock.

Such plants can be operated only in interconnected system, where other generating

TPP & NPP) are available during their off load period.

During peak hours the turbine drives the generator and generates elect

TECHNICAL EDUCATIOD

Page No: 13 of 33

(Note: Student may write operation in different way also)

Water stored at high level by constructing dam across river. This stored water has



into mechanical energy and Alternator is coupled to water

What are pumped storage plants? Draw a neat labelled sketch of pumped storage plant.

peration-1 Mark &


by constructing a dam.

pond connected through penstock.

, where other generating

) are available during their off load period.

During peak hours the turbine drives the generator and generates electrical energy.


Subject Code: 12057

� During OFF peak hours the

which now works as

� Raising the water from tail water pond to head water pond through penstock.

� In this case, Francis turbine is used

Applications of Pumped storage plants:

i) To supply peak load.

d) Draw the labelled block diagram of diesel power plant.

e) State the meaning of operation, maintenance

main troubles of diesel power plant and their shooting.

(Operation-1/2

Operation:

� The condition of operation

of water & oil etc is maintained at regular intervals.




Model Answer

peak hours the generator operates as a motor. And drives the

which now works as centrifugal pump.

Raising the water from tail water pond to head water pond through penstock.

In this case, Francis turbine is used

Applications of Pumped storage plants:

load.

Draw the labelled block diagram of diesel power plant. ( Diagram –


State the meaning of operation, maintenance and trouble of diesel power plant. Give

main troubles of diesel power plant and their shooting.

1/2 Mark, Maintenance -1.5 Marks & Trouble shooting

condition of operation oil pressure, water pressure, inlet and outlet

water & oil etc is maintained at regular intervals.

TECHNICAL EDUCATIOD

Page No: 14 of 33

. And drives the turbine

Raising the water from tail water pond to head water pond through penstock.

– 4 Mark)

and trouble of diesel power plant. Give

Marks & Trouble shooting – 2 Mark)

oil pressure, water pressure, inlet and outlet temperatures


Subject Code: 12057

� Correct record of instrument reading ammeter, voltmeter,

meter should be taken at regular int

� A separate log sheet is used for keeping record.

Diesel power station maintenance include:

1. Cleaning of fuel oil from dirt and impurities by means of filters.

2. Occasionally all fuel is drained and fuel tank are cleaned thoroughly.

3. Air filter should be cleaned thoroughly.

4. The temperature and quantity of coolant should be checked.

5. Lubrication & engine oil also should be checked.

6. Temperatures of Exhaust gases are

Maintenance schedule for Diesel Power plant: (Note: At least four points should be

S.No Maintenance 1 Check Coolant Heater 2 Check Coolant Level 3 Check oil level 4 Check fuel level 5 Check charge air piping 6 Clean air cleaner 7 Check battery charger 8 Check drain water from fuel tank9 Check coolant concentration10 Check drive belt tension11 Check starting compressor12 Change oil & oil filter 13 Change coolant & coolant filter14 Change crank case breather15 Change air cleaner 16 Check radiator hoses 17 Change fuel filter 18 Clean cooling system




Model Answer

Correct record of instrument reading ammeter, voltmeter, and wattmeter

meter should be taken at regular intervals.

A separate log sheet is used for keeping record.

Diesel power station maintenance include:-

Cleaning of fuel oil from dirt and impurities by means of filters.

Occasionally all fuel is drained and fuel tank are cleaned thoroughly.

should be cleaned thoroughly.

The temperature and quantity of coolant should be checked.

Lubrication & engine oil also should be checked.

Temperatures of Exhaust gases are also checked.

OR

Maintenance schedule for Diesel Power plant: (Note: At least four points should be covered)

Daily Weekly Monthly � � � �

� � �

Check drain water from fuel tank � Check coolant concentration � Check drive belt tension �

starting compressor � �

Change coolant & coolant filter Change crank case breather

TECHNICAL EDUCATIOD

Page No: 15 of 33

and wattmeter and energy

Cleaning of fuel oil from dirt and impurities by means of filters.

Occasionally all fuel is drained and fuel tank are cleaned thoroughly.

covered)

Six month Yearly

� � �

� �

�


Subject Code: 12057

Trouble Shooting for Diesel Power

S.No Trouble (Complaint, problems) causes

1 Poor Fuel Quality

2 Air in fuel

3 No fuel to cylinder 4 Instticient fuel supply

5 Fuel Leaks at injection lines

6 Some or all injectors bad

7 Air intake restricted

8 Low compression

9 Incorrect engine timing

10 Incorrect starting procedure

11 Low cranking speed

12 Internal engine problem

f) State two applications of diesel power plant. How the operation of diesel power plant can

be automatic.

Applications of Diesel Power Plant:

i) It can be used as a standby (emergency) power plant to maintain continuity of supply.

ii) It is suitable where

iii) It is widely used in transportation system. E.g. Elect. Traction, Ship, Aero plane etc.

iv) It is suitable as a peak load power plant for short duration.




Model Answer

Trouble Shooting for Diesel Power Plant: (Note: At least four points should be covered)

Will Not start

Hard to start

Start stalls

Run rough

Lack of power

Black smoke

� � � � �

� �

� � � � �

�

� � � �

� �

� �

� � �

� �

� �

� � � �

State two applications of diesel power plant. How the operation of diesel power plant can

(Application -3 Marks & Automatic operation

Applications of Diesel Power Plant: (Any two points expected)

as a standby (emergency) power plant to maintain continuity of supply.

It is suitable where power requirement is small.

It is widely used in transportation system. E.g. Elect. Traction, Ship, Aero plane etc.

It is suitable as a peak load power plant for short duration.

TECHNICAL EDUCATIOD

Page No: 16 of 33

(Note: At least four points should be covered)

Black smoke

While Smoke

Shooting

Change the fuel

Remove the air

Fill the fuel � Clean the

fuel supply injectors

Remove the leakage

� Replace by new

� Clean the air filter

� Check & correct

� Adjust the timing

Use correct starting procedure

Check & correct

� Check & correct

State two applications of diesel power plant. How the operation of diesel power plant can

Automatic operation – 1 Mark)

as a standby (emergency) power plant to maintain continuity of supply.

It is widely used in transportation system. E.g. Elect. Traction, Ship, Aero plane etc.


Subject Code: 12057

v) Mobile DEPP mounted on vehicle

temporary purpose.

vi) It is used in remote places where supply from grid is not possible.

vii) It is very economical to supply power to small scale industry which works for seasonal

period.

viii) The use of such plant is very common during construction stage of HPP/TPP/NPP a

other construction.

Operation of diesel power plant can be made automatically:

When in coming supply to load fails due to any reason then generator will

automatically starts after three minutes

called as Auto Mains Failure (AMF)

will automatically stop after three minutes


a) “The non- conventional sources were known to man since early days, still they were not

developed” comment and give reasons.

The non- conventional sources were known to man since early days,

developed because of following reason:

i) Initial cost per MW is high

ii) No firm generating capacity.

iii) Its efficiency is low.

iv) There is limitation on site selection in some cases.

v) Generating capacity is less.

vi) There is no guaranty that power is generated during peak hours or whenever needed.

vii) Power generation is no

viii) Cost per unit is high

ix) It is not reliable.

x) Life is less.




Model Answer

Mobile DEPP mounted on vehicle is used in emergency requirement and for

rary purpose.

It is used in remote places where supply from grid is not possible.

It is very economical to supply power to small scale industry which works for seasonal

The use of such plant is very common during construction stage of HPP/TPP/NPP a

other construction.

Operation of diesel power plant can be made automatically:


automatically starts after three minutes or preset time for this purpose a separate panel

Auto Mains Failure (AMF) is necessary also when supply restored generator

will automatically stop after three minutes or preset time.

of the following

conventional sources were known to man since early days, still they were not

developed” comment and give reasons.

conventional sources were known to man since early days,

developed because of following reason: (Any Four reasons expected 1 Mark each

per MW is high.

No firm generating capacity.

Its efficiency is low.

There is limitation on site selection in some cases.

Generating capacity is less.

There is no guaranty that power is generated during peak hours or whenever needed.

Power generation is not phase with demand.

Cost per unit is high in some power plant.

TECHNICAL EDUCATIOD

Page No: 17 of 33

used in emergency requirement and for

It is used in remote places where supply from grid is not possible.

It is very economical to supply power to small scale industry which works for seasonal

The use of such plant is very common during construction stage of HPP/TPP/NPP and


for this purpose a separate panel

is necessary also when supply restored generator

16 Marks



1 Mark each)

There is no guaranty that power is generated during peak hours or whenever needed.


Subject Code: 12057

b) What is mean solar cell? State working of solar cell with neat sketch.

Solar Cell:

Which converts solar energy (heat energy) directly into electrical energy (DC) is

called as solar cell. OR

Silicon solar cell consists of a thin slice of single crystal P

upto 2 cm2 into which a very thin (0.5 micron) layer of N

Working:-

Solar cell operates on principle of Photo

generating an emf (DC) when it absorbs sun

Solar cell works in following steps.

1. Photons in sunlight hit the solar panel and absorbed by semiconducting material

(such as silicon)

2. Electrons (negatively charged) are knocked loose from their atom causing an

electric potential difference.

3. Thus converts solar energy into electrical energy without any waste products.

Working:-

Photovoltaic cell is small semi conductor device which has light sensitive P

junction. It made up semi

Type layer is thick while the N

type semiconductor is obtained. When sunlight strikes the N

waves of light energy penetrate up to the P

energy are absorbed in semi conductor, and sunlight energy is greater than energy gap,




Model Answer

What is mean solar cell? State working of solar cell with neat sketch.

(Meaning -2 Marks & Figure – 1 Mark, Working


OR

Silicon solar cell consists of a thin slice of single crystal P

into which a very thin (0.5 micron) layer of N-type material is diffused.


Solar cell operates on principle of Photo-voltaic effect which is process of

generating an emf (DC) when it absorbs sun radiations OR

Solar cell works in following steps.

Photons in sunlight hit the solar panel and absorbed by semiconducting material

h as silicon)

Electrons (negatively charged) are knocked loose from their atom causing an

electric potential difference.

Thus converts solar energy into electrical energy without any waste products.

OR

Photovoltaic cell is small semi conductor device which has light sensitive P

junction. It made up semi-conducting material and these cells are light sensitive. The p

Type layer is thick while the N-type layer is thin. When trivalent impurity is added, P

type semiconductor is obtained. When sunlight strikes the N-type layer, some of the

waves of light energy penetrate up to the P-type layer. When photons from the sunli


TECHNICAL EDUCATIOD

Page No: 18 of 33

What is mean solar cell? State working of solar cell with neat sketch.

1 Mark, Working -1 Marks)


Silicon solar cell consists of a thin slice of single crystal P-type silicon material

type material is diffused.


voltaic effect which is process of

Photons in sunlight hit the solar panel and absorbed by semiconducting material

Electrons (negatively charged) are knocked loose from their atom causing an

Thus converts solar energy into electrical energy without any waste products.

Photovoltaic cell is small semi conductor device which has light sensitive P-N

conducting material and these cells are light sensitive. The p-

type layer is thin. When trivalent impurity is added, P-

type layer, some of the

type layer. When photons from the sunlight



Subject Code: 12057

electron-hole pairs are formed. Electrons are released from N

created in P-type material electrical circuit is completed and flow of curr

Photo voltaic cell system converts solar energy directly into electrical energy

without any waste products.

c) State the advantages and Limitations of Tidal power generation.

Advantages of Tidal Power generation:

i) It is clean & free from air pollution.

ii) Fuel is freely available.

iii) No transportation cost on fuel & waste disposal problem.

iv) It does’t require any combustion of fuel.

v) It is independent on external fuel supply & fluctuations in existing fuel rate.

vi) It is renewable energy source.

vii) Tidal energy is in exhaustive.

viii) Long Life

ix) Cost per unit is less.

x) It is independent on weather & seasonal condition.

xi) Operation and maintenance cost is less.

xii) No waste of useful land for power plant erecting.

xiii) Tides are totally predictable (both in terms of timing & force)

xiv) Tides can exchange millions of gall

xv) Dam constructed for ti

storm tides & provide readymade road bridge.

Limitations of Tidal Power generation:

i) High capital cost due to large

ii) There is limitation on site selection because it requires minimum tidal range between

5-8 meter.

iii) It provides power only for 10 hours per day.




Model Answer

hole pairs are formed. Electrons are released from N-type material and holes are

type material electrical circuit is completed and flow of curr


without any waste products.

State the advantages and Limitations of Tidal power generation.

(Advantages -2 Marks & Limitation

Advantages of Tidal Power generation: (Any Four Expected)

It is clean & free from air pollution.

Fuel is freely available.

transportation cost on fuel & waste disposal problem.

It does’t require any combustion of fuel.

It is independent on external fuel supply & fluctuations in existing fuel rate.

It is renewable energy source.

Tidal energy is in exhaustive.

r unit is less.

It is independent on weather & seasonal condition.

Operation and maintenance cost is less.

No waste of useful land for power plant erecting.

Tides are totally predictable (both in terms of timing & force)

Tides can exchange millions of gallons of water in just minutes.

Dam constructed for tidal power plant may protect coast line again damage from high

storm tides & provide readymade road bridge.

Limitations of Tidal Power generation: (Any Four Expected)

High capital cost due to large length & size of dam.

limitation on site selection because it requires minimum tidal range between

It provides power only for 10 hours per day.

TECHNICAL EDUCATIOD

Page No: 19 of 33

type material and holes are

type material electrical circuit is completed and flow of current takes place.


2 Marks & Limitation – 2 Mark)

It is independent on external fuel supply & fluctuations in existing fuel rate.

n just minutes.

line again damage from high

limitation on site selection because it requires minimum tidal range between


Subject Code: 12057

iv) There is no guaranty that power is generated during peak hours.

v) Design of dam/ barrage

vi) Power generation is not in phase with demand.

vii) Changing of tidal range in two weeks period produces changing power generation.

viii) It affects marine life of fish, animals & environmental at that location/ co

ix) It may affect/ abstracti

x) No firm generating capacity.

xi) Such power plants are located away from load centre so transmission cost increases.

xii) As water is salted, there is possibility of rusting of equipments.

xiii) Time required for completion of project is more due

d) Draw the neat sketch of Ocean tidal energy conversion plant. State the limitations of tidal

power Generation.

Figure for Two Basine, Linked basine scheme:




Model Answer

There is no guaranty that power is generated during peak hours.

barrage is quit complicated.

Power generation is not in phase with demand.

Changing of tidal range in two weeks period produces changing power generation.

It affects marine life of fish, animals & environmental at that location/ co

It may affect/ abstraction to marine traffic.


Such power plants are located away from load centre so transmission cost increases.

As water is salted, there is possibility of rusting of equipments.

Time required for completion of project is more due to construction of dam.

Draw the neat sketch of Ocean tidal energy conversion plant. State the limitations of tidal

(Any one Diagram is expected-2 Marks & Limitation

Figure for Two Basine, Linked basine scheme:


TECHNICAL EDUCATIOD

Page No: 20 of 33



It affects marine life of fish, animals & environmental at that location/ coastal life.



to construction of dam.

Draw the neat sketch of Ocean tidal energy conversion plant. State the limitations of tidal

2 Marks & Limitation – 2 Mark)

OR


Subject Code: 12057

Layout of Ebb generation Tidal power Plant or out flow generation:

Limitations of Tidal Power generation:

i) High capital cost due to large length & size of dam.

ii) There is limitation on site selection because it requires minimum tidal range between

5-8 meter.

iii) It provides power only for 10 hours per day.

iv) There is no guaranty that power is generated during peak hours.

v) Design of dam/ barrage

vi) Power generation is not in phase with demand.

vii) Changing of tidal range in two weeks period produces changing power generation.

viii) It affects marine life of fish, animals & environmental at that location/ co

ix) It may affect/ abstraction to marine traffic.

x) No firm generating capacity.

xi) Such power plants are located away from load centre so transmission cost increases.

xii) As water is salted, there is possibility of rusting of equipments.

xiii) Time required for completio




Model Answer

bb generation Tidal power Plant or out flow generation:-

Limitations of Tidal Power generation: (Any Four Point Expected)

capital cost due to large length & size of dam.

There is limitation on site selection because it requires minimum tidal range between

It provides power only for 10 hours per day.


barrage is quit complicated.

Power generation is not in phase with demand.


It affects marine life of fish, animals & environmental at that location/ co

It may affect/ abstraction to marine traffic.




Time required for completion of project is more due to construction of dam.

TECHNICAL EDUCATIOD

Page No: 21 of 33

(Any Four Point Expected)

There is limitation on site selection because it requires minimum tidal range between



It affects marine life of fish, animals & environmental at that location/ coastal life.



n of project is more due to construction of dam.


Subject Code: 12057

e) State the factors for selection of site for wind mills. Explain briefly. Mention the speciality

of wind mill generator. (

generator – 2 Mark)

The Factors for selection of site for Wind Mills:

i) The site should be selected where winds are strong i.e where pressure of wind is high

and there is continuity (10

ii) It is better to choose a site near the seashore (

iii) Winds turbines are also installed OFF shore (in ocean) OFF shore wind turbine

generate more electricity than those on land because the wind at sea is typically

stronger and more constant than ON shore.

iv) Wind pressure is also high in hilly are

v) Site should be convenient for transportation facility.

vi) The cost of land should be low.

vii) Plant must be installed on tall towers (45m to 149 m) as wind pressure is available

with higher velocity.

The specialty of wind mill generator

Note: In this case credit may be given by judgment on part of examiner of relevant answer based on candidate understands.

Typically wind turbines generate electricity through

directly connected with the electricity grid.

double-fed three-phase induction

converter) ensure that the generator works with high efficiency over the entire speed range.

heating winding is installed to prevent damage to the generator due to

there are sensors to monitor the temperature

electronics are cooled by a water

In a turbine generator, magnets spin around a coil to produce current. The faster

the magnets spin, the more current is induced in the c

generator's slower spinning rate, the diameter of the generator's

containing more magnets which lets it create




Model Answer

State the factors for selection of site for wind mills. Explain briefly. Mention the speciality

(Factors for selection wind Mill -2 Marks &

Factors for selection of site for Wind Mills: (Any Four Point Expected)

should be selected where winds are strong i.e where pressure of wind is high

and there is continuity (10-15km/hr) and above.

It is better to choose a site near the seashore (coastal area)

Winds turbines are also installed OFF shore (in ocean) OFF shore wind turbine


stronger and more constant than ON shore.

Wind pressure is also high in hilly area so wind turbines are located in hilly area.

Site should be convenient for transportation facility.

The cost of land should be low.

Plant must be installed on tall towers (45m to 149 m) as wind pressure is available

with higher velocity.

of wind mill generator:

Note: In this case credit may be given by judgment on part of examiner of relevant based on candidate understands.

Typically wind turbines generate electricity through asynchronous machines

directly connected with the electricity grid. The wind turbine generator is equipped with a

phase induction generator. The advanced power electronics (IGBT

that the generator works with high efficiency over the entire speed range.

heating winding is installed to prevent damage to the generator due to

there are sensors to monitor the temperature in the generator. The generator and the power

electronics are cooled by a water-air heat exchanger. OR


the magnets spin, the more current is induced in the coil. To make up for a direct drive

generator's slower spinning rate, the diameter of the generator's rotor

containing more magnets which lets it create a lot of power when turning slowly. To reduce

TECHNICAL EDUCATIOD

Page No: 22 of 33

State the factors for selection of site for wind mills. Explain briefly. Mention the speciality

2 Marks & Speciality of

(Any Four Point Expected)

should be selected where winds are strong i.e where pressure of wind is high

Winds turbines are also installed OFF shore (in ocean) OFF shore wind turbine


a so wind turbines are located in hilly area.

Plant must be installed on tall towers (45m to 149 m) as wind pressure is available

Note: In this case credit may be given by judgment on part of examiner of relevant

asynchronous machines that are

The wind turbine generator is equipped with a

d power electronics (IGBT

that the generator works with high efficiency over the entire speed range. A

heating winding is installed to prevent damage to the generator due to damp. In addition,

The generator and the power


oil. To make up for a direct drive

rotor is increased hence

a lot of power when turning slowly. To reduce


Subject Code: 12057

the generator weight some constructors use

rotor, while conventional turbine generato

generator itself. To enhance their competitiveness, the design of smaller generators with

improved torque is still an active res

f) Draw the neat labelled diagram of wind mill and state its applications.




Model Answer

the generator weight some constructors use permanent magnets (PM) in the generators'

rotor, while conventional turbine generators use electromagnets fed with electricity from the


improved torque is still an active research area.

Draw the neat labelled diagram of wind mill and state its applications.

(Any one Diagram is expected-2 Marks & Application

or equivalent figure OR

TECHNICAL EDUCATIOD

Page No: 23 of 33

(PM) in the generators'

fed with electricity from the


Draw the neat labelled diagram of wind mill and state its applications.

2 Marks & Application – 2 Mark)

OR


Subject Code: 12057

Application of Wind Mill:

i) Wind energy is used to generate electrical

commercial wind turbine.

ii) Wind energy can be generated electrical energy in small scale for residential, small

commercial, hotels and hospitals etc.

iii) For pumping the water from well.

iv) Wind energy can be used for grindin


a) What is the meaning of Bio

calorific value. (Meaning

Bio-mass and Bio-gas:-

The power plant in which biomass is used as a fuel to generate electrical is known as

biomass power plant.




Model Answer


Application of Wind Mill: (Any Two Expected)

Wind energy is used to generate electrical energy in large scale with the help of

commercial wind turbine.

Wind energy can be generated electrical energy in small scale for residential, small

commercial, hotels and hospitals etc.

For pumping the water from well.

Wind energy can be used for grinding purpose.

of the following

What is the meaning of Bio-mass and Bio-gas energy? Give composition of Bio

Meaning-2 Marks & Composition of Bio-gas-1&Calorific Value


TECHNICAL EDUCATIOD

Page No: 24 of 33

energy in large scale with the help of

Wind energy can be generated electrical energy in small scale for residential, small

16 Marks

gas energy? Give composition of Bio-gas and its

1&Calorific Value –1 Mark)



Subject Code: 12057

Composition of Bio-gas and its calorific Value:

In biogas plant, biogas also called as land

of biogas is as below (Note: Only Name of components is expected)

S.No Compound

1 Methane

2 Carbon dioxide

3 Nitrogen

4 Hydrogen

5 Hydrogen sulphide

6 Oxygen

Out of which methane gas is useful to produce electricity by direct combustion or to run

the gas engine in combination with generator. Calorific Value of

i) At 40% methane: 3124 Kcal / m

ii) At 50% methane: 4429 Kcal / m

iii) At 55% methane: 4713 Kcal / m

b) A generating Station has a connected load of 60 MW and maximum demand of 25 MW.

The units generated being 60 x

factor. (Formula

DemandAverage =

=

Load Factor Maximum

Average=

1025

315.6849

×=




Model Answer

gas and its calorific Value:

In biogas plant, biogas also called as land fill gas (LFG) is produced. The composition

(Note: Only Name of components is expected)

Compound Formula (Not expected) % (Not expected)

CH4 50-

Carbon dioxide CO2 25-

N2 0-10 %

H2 0-1 %

Hydrogen sulphide H2S 0-3 %

O2 0 %


the gas engine in combination with generator. Calorific Value of Methane:

40% methane: 3124 Kcal / m3

At 50% methane: 4429 Kcal / m3

At 55% methane: 4713 Kcal / m3

A generating Station has a connected load of 60 MW and maximum demand of 25 MW.

The units generated being 60 x 106 KWh per annum. Calculate load factor

(Formula-1 Mark for each factor & Answer-1 Mark for each factor)

yearinHours

annumgeneratedUnits /

kw315.68498760

1060 6

=×=

demandMaximum

DemandAverage

%39.27273.010

3153

or=

OR

TECHNICAL EDUCATIOD

Page No: 25 of 33

gas (LFG) is produced. The composition

(Note: Only Name of components is expected)

(Not expected)

-75 %

-50 %

10 %

1 %

3 %

0 %


Methane:

A generating Station has a connected load of 60 MW and maximum demand of 25 MW.

Calculate load factor and demand

1 Mark for each factor)


Subject Code: 12057

factorLoad

= 8760

60

××

Demand Factor connected

Maximum=

60

25=

Demand Factor = 0.4166

Average Demand Units=

60=

c) Differentiate between load curve and load duration curve.

1 mark to each point)

S.No Load Curve

1 It is graphical representation of load (KW/MW) w.r.t time (hrs).

2 Load at any time during a day determine

3 Load curve helps selection of most economical size (rating) generating units (set of generator)

4 Operation schedule of generating station can be determined

5




Model Answer

demandMaximum

generatedunitsofNo

×=

8760

.

%39.27273.01025

103

6

or=×

×

loadconnected

demandMaximum

0.4166

yearinHours

annumgeneratedUnits /

kw315.68498760

1060 6

=×

Differentiate between load curve and load duration curve. (Any four point expected

Load Curve Load Duration CurveIt is graphical representation of load (KW/MW) w.r.t time (hrs).

It is drawn from load curve. It is the graph of load (KW/MW) arranged in descending order of magnitude w.r.t time

Load at any time during a day are How long a particular load exist

Load curve helps selection of most economical size (rating) & number of generating units (set of generator)

It helps to determine distribution of load between different generating set

Operation schedule of generating station It helps to determine distribution of load between different generating set

TECHNICAL EDUCATIOD

Page No: 26 of 33

(Any four point expected -

Load Duration Curve is drawn from load curve. It is the graph

of load (KW/MW) arranged in descending order of magnitude w.r.t time How long a particular load exist

It helps to determine distribution of load between different generating set

It helps to determine distribution of load generating set


Subject Code: 12057

d) A generating station has following daily load cycle.

Time (Hours) 0-6 Load (MW) 40

i) Maximum Demand=? ii) Units generated per day=? iii) Average load+?

iv) Load Factor?

Solutions:

i) It is clear from the load curve that maximu

and occurs during the period

Maximum Demand:

ii) Units generated /day =

KWhinArea (=

640(103 ×=

240(103 +=

240(103 +=

3101460×=




Model Answer

A generating station has following daily load cycle.

6-10 10-12 12-16 60 80 100

Maximum Demand=? ii) Units generated per day=? iii) Average load+?

Graph:

It is clear from the load curve that maximum demand on the power station is

and occurs during the period 12-16

Demand: 100 MW -------------------------------------------------

Units generated /day =

curveloadtheunderKWh)

)43047541002804606 ×+×+×+×+×+

kWh)120300400160240 +++++

kWh)120300400160240 +++++

KWh3 -------------------------------------------------

TECHNICAL EDUCATIOD

Page No: 27 of 33

16-20 20-24 75 30

Maximum Demand=? ii) Units generated per day=? iii) Average load+?

m demand on the power station is 100 MW

------------------------------------------------- (1 Mark)

------------------------------------------------- (1 Mark)


Subject Code: 12057

iii) Average Load =

Units=

iv) Load Factor =

=Maximum

Average

.60=

e) State the criteria by choice of size and number of generator units in a generating station.

Explain briefly.

Following points should be considered while selecting size & number of generating units in generating station.

i) The size & number of generating units should be so selected that they approximately

match (fit) with annual load curve of generating station.

ii) Select the large number of generating units of different small capacity to match the load

curve.

iii) The tendency to select a large number of units of smaller capacity in order to fit the

load curve very accurately should be avoided.

iv) The installed capacity of the plant should be at least 15

demand to meet the future load requirement.

v) There should be spare generating unit to increase the reliability.

f) What is meant by water hammer action in penstock of hydro

method to reduce it?

Explanation:-

When load on power plant or alternator d

discharge of water. Due to sudden reduction in water discharge causes increase in pressure




Model Answer

hours

daypergeneratedUnits.60833

24

101460

24

3

=×=

60833.010100

33.608333

=×

=demandMaximum

loadAverage

%83. ----------------------------------------------------------------

State the criteria by choice of size and number of generator units in a generating station.

Following points should be considered while selecting size & number of generating

units in generating station. (Any four point expected- 1 Mark each pointThe size & number of generating units should be so selected that they approximately

tch (fit) with annual load curve of generating station.

Select the large number of generating units of different small capacity to match the load

The tendency to select a large number of units of smaller capacity in order to fit the

accurately should be avoided.

The installed capacity of the plant should be at least 15-20% more than maximum

demand to meet the future load requirement.

There should be spare generating unit to increase the reliability.

What is meant by water hammer action in penstock of hydro-electric power station and

(Water Hammer effect-2 Mark & method of reduce

When load on power plant or alternator decreases then Governor (valve) reduces

discharge of water. Due to sudden reduction in water discharge causes increase in pressure

TECHNICAL EDUCATIOD

Page No: 28 of 33

KW33. ------- (1 Mark)

---------------------------------------------------------------- (1 Mark)

State the criteria by choice of size and number of generator units in a generating station.

Following points should be considered while selecting size & number of generating 1 Mark each point)

The size & number of generating units should be so selected that they approximately

Select the large number of generating units of different small capacity to match the load

The tendency to select a large number of units of smaller capacity in order to fit the

20% more than maximum

There should be spare generating unit to increase the reliability.

electric power station and

& method of reduce -2 Mark)

Governor (valve) reduces

discharge of water. Due to sudden reduction in water discharge causes increase in pressure of the


Subject Code: 12057

water in the penstock. Due to high pressure penstock may damage. This effect is known as

‘Water hammer effect’. OR

When load on power plant or alternator decreases then

� Governor (valve) reduces discharge of water.

� Due to sudden reduction in water discharge causes increase in pressure in the penstock.

� Due to high pressure penstock may damage.

� This effect is known as

Effect is reduced: -

With the help of surge tank water hammer effect is eliminated

At that time surge tank helps by storing this rejected water immediately. In this way it avoids

water hammer effect.


a) State four advantages of interconnected power station.

i) Reduced Overall installed Capacity:


With interconnection between power systems, peak demand in an area

power from neighboring area. Thus, it also reduces investment and fulfills the peak

demand.

ii) Better Utilization Hydro Power:

In combined power system, hydro power can be utilized in more effectiv

during rainy season, hydro power plant can be utilized, while during draught periods, steam

power plant can be used as base load plant.

iii) Reliability of Supply:

The reliability of steam power plants depends upon the coal su






Model Answer

the penstock. Due to high pressure penstock may damage. This effect is known as

OR

When load on power plant or alternator decreases then

Governor (valve) reduces discharge of water.

Due to sudden reduction in water discharge causes increase in pressure in the penstock.

Due to high pressure penstock may damage.

This effect is known as ‘Water hammer effect.

With the help of surge tank water hammer effect is eliminated


of the following

State four advantages of interconnected power station.

(Any four Advantages Expected

i) Reduced Overall installed Capacity:-


With interconnection between power systems, peak demand in an area


ii) Better Utilization Hydro Power: -

In combined power system, hydro power can be utilized in more effectiv


can be used as base load plant.

Reliability of Supply: -

The reliability of steam power plants depends upon the coal su



TECHNICAL EDUCATIOD

Page No: 29 of 33

the penstock. Due to high pressure penstock may damage. This effect is known as

Due to sudden reduction in water discharge causes increase in pressure in the penstock.

With the help of surge tank water hammer effect is eliminated OR


16 Marks

four Advantages Expected-1 Mark to each)










Subject Code: 12057

iv) High unit size possible:



v) Improved quality of voltage and frequency:


inter connections, the system becomes stronger & the effect of load is reduced.

vi) Exchange of peak loads:

If the load curve of powe


vii) Use of older Plants:-

The interconnected system makes it possible to use


alone, yet they have sufficient capacity to carry short peaks up load when inter


viii) Insure Economical operation:



more efficient plants work for peak load

ix) Increases Diversity factor:


inter-connected stations are different. So, diversity factor of the system is improved,


x) Increases load factor:-


xi) Reduces Plant Reserve capacity:


when several power stations are connected in parallel, the reserve capacity of the system is


xii) Better utilization of natural resources:






Model Answer

iv) High unit size possible:-



Improved quality of voltage and frequency:-



Exchange of peak loads:-



-



have sufficient capacity to carry short peaks up load when inter


conomical operation:-




Increases Diversity factor:-



the effective capacity of the system.

-


Reduces Plant Reserve capacity:-




Better utilization of natural resources:



TECHNICAL EDUCATIOD

Page No: 30 of 33




r station shows a peak demand that is greater than the rated


older and less efficient plants to


have sufficient capacity to carry short peaks up load when inter-connected









Subject Code: 12057

b) Compare thermal, Hydro, Nuclear and diesel Power plants on the basis of i)

ii) Use as base load or peak load .

S.No Basis of point Thermal

1 Running

Cost

2 Use as base

load or peak

load

Base load

c) What is meant by economic loading of interconnected power stations? How the economic

loading is achieved?

Note: - In this questions credit may be given by judgment on part of examiner of relevant answer based on candidate understand

Economic Loading means:

The power plant whose generating cost per unit is less will share maximum load during

whole day. And the power plant whose generating cost per unit is more will share minimum

load for few hours during a day (pea

power system.

Economic loading is achieved as shown in figure

Following figure indicates priority of type of plant share the load




Model Answer

Compare thermal, Hydro, Nuclear and diesel Power plants on the basis of i)

ii) Use as base load or peak load .

Thermal P.P

Hydro P.P Nuclear P.P

High Lowest Higher than

Base load Peak load also Large

storage H.P.P may be used

as a base load power plant

Base load

What is meant by economic loading of interconnected power stations? How the economic

(Economic loading -2 Mark & How it is

In this questions credit may be given by judgment on part of examiner of answer based on candidate understanding.

Economic Loading means:



load for few hours during a day (peak load) is called economic loading of interconnected

Economic loading is achieved as shown in figure:

Following figure indicates priority of type of plant share the load.


TECHNICAL EDUCATIOD

Page No: 31 of 33

Compare thermal, Hydro, Nuclear and diesel Power plants on the basis of i) Running cost

(4 Mark)

Nuclear P.P Diesel P.P

Higher than

T.P.P

Highest

Base load Peak load

What is meant by economic loading of interconnected power stations? How the economic

How it is achieved-2 Mark)

In this questions credit may be given by judgment on part of examiner of



k load) is called economic loading of interconnected



Subject Code: 12057

d) Differentiate between state grid and national grid. What precautions must be taken in

case of national grid? (Any two

Mark)

Note: - In this questions credit may be given by judgment on part of examiner of relevant answer based on candidate understands.

S.No. State Grid

1 All major generating stations in state

are interconnected to each other

through transmission line is called as

state grid.

2 Control of authority is state level load

dispatch centre

Precautions must be taken in case of national Grid:

Precaution should be taken that l

cascade tripping during peak load period.

e) Explain how to decide the priority of types of plant to share the load.

Note: - In this questions credit may be given by judgment on part of examiner of relevant answer based on candidate understands.

Following figure indicates priority of type of plant share




Model Answer

between state grid and national grid. What precautions must be taken in

Any two Difference point -2 Mark each point

In this questions credit may be given by judgment on part of examiner of relevant answer based on candidate understands.

State Grid National Gridgenerating stations in state

are interconnected to each other

through transmission line is called as

All state grids are interconnected to each

other through transmission line is called

‘National grid.

Control of authority is state level load Control of authority is National level load

dispatch centre

Precautions must be taken in case of national Grid:

should be taken that load on grid is adjusted in such way that,

cascade tripping during peak load period.

Explain how to decide the priority of types of plant to share the load.

In this questions credit may be given by judgment on part of examiner of relevant on candidate understands.

Following figure indicates priority of type of plant share the load.


TECHNICAL EDUCATIOD

Page No: 32 of 33

between state grid and national grid. What precautions must be taken in

each point & Precautions -2

In this questions credit may be given by judgment on part of examiner of relevant

National Grid All state grids are interconnected to each

other through transmission line is called

Control of authority is National level load

is adjusted in such way that, avoid

Explain how to decide the priority of types of plant to share the load.

In this questions credit may be given by judgment on part of examiner of relevant (4Marks)



Subject Code: 12057

f) Define the following terms related to Economics of power generation connected load,

spinning reserve, plant capacity factor and plant use factor.

1. Connected Load :

It is the sum of continuous

are in use or not use of each consumer.

The sum of continuous rating of all the equipments in consumer premises is the

connected load of consumer and

connected to the power station or power system.

2. Spinning Reserve :

It is the generating capacity to bus bar & ready to take a load.

3. Plant Capacity Factor

It is the ratio of actual energy produced to the maximum possible energy that could

have been produced during a given period.

FactorCapacityPlant

FactorCapacityPlant

FactorCapacityPlant

CapacityPlant

∴ FactorCapacityPlant

4. Plant Use factor:

It is the ratio of number of units (KWH) generated to the product of installed capacity

of plant & the number of hours for which the plant was in operation.

FactorUsePlant =

------------------------------------------------------




Model Answer

Define the following terms related to Economics of power generation connected load,

spinning reserve, plant capacity factor and plant use factor.

( Each Definition

It is the sum of continuous supply of all equipments connected to supply system which

are in use or not use of each consumer. OR


connected load of consumer and the sum of connected load of all the consumers is the

connected to the power station or power system.

It is the generating capacity to bus bar & ready to take a load.

Plant Capacity Factor:


have been produced during a given period.

havecouldthatenergypossibleMaximum

producedKWHenergyActualFactor

)(=

plantofcapacityRatedInstalled

DemandAverageFactor

)(=

OR

InstalledperiodthatinhrsofNumber

aduringgeneratedKWHTotalFactor

×=

ratedInstalled

Maximum

demandMaximum

demandAvrageFactor ×=

factornUtilizatiofactorLoadFactor ×=


the number of hours for which the plant was in operation.

hoursofNumberplantofcapacityInstalled

StationgeneratedKWHunitsofNumber

×()(

------------------------------------------END---------------------------------------------------

TECHNICAL EDUCATIOD

Page No: 33 of 33

Define the following terms related to Economics of power generation connected load,

Each Definition -1 Mark each)

supply of all equipments connected to supply system which


of all the consumers is the


producedbeenhave

produced OR

OR

ORplantofcapacityratedInstalled

periodgivena

plantofcapacityrated

demandMaximum


the number of hours for which the plant was in operation.

operationinplanthours

KWHinpoStation )/

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