Post on 01-Mar-2018
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POWER PLANT ENGINEERING
TWO MARK QUESTIONS AND ANSWERS
ACADEMIC YEAR 2015 - 2016
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UNIT I
INTRODUCTION TO POWER PLANT AND BOILERS
1 What i !"a#t $% &'(") &*a#t+
Power can be defined as the rate of flow of energy and state that a power plant is a Unit
built for production and delivery of a flow of mechanical work and electrical energy. A
machine or assembling of equipment that produces and delivers a flow of mechanical and
electrical energy is a power plant.
2 What a)" th" t%&" ', &'(") &*a#t+
Steam power plant
Hydro electric power plant
Diesel power plant
uclear power plant
!as turbine power plant
"HD power plant
Lit th" ,a.t') ', &'(") &*a#t &"),')!a#."/
#he performance of a power plant can be e$pressed through some common
Performance factors as
%. Heat rate
&. 'apacity factor(. )conomic efficiency
*. +oad factor
,. -perational efficiency
What a)" th" !a') &'(") *i!itati'# ', .'#"#ti'#a* "#")3% '4)."+
%.esources for power generation i.e/ coal/ gas etc./ are limited
&.#he hydro power is seasonal and varies depending upon the rainfall
in the catchment areas
(.Submersion of land area due to raise in water level*. 'entrali0ed power generation and distribution of the same to long distances will
result in high losses.
,.#he energy conversion process from thermal power pro1ects results in emission
of green house gases
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5 Lit '4t th" a)i'4 .'#"#ti'#a* a# #'# .'#"#ti'#a* &'(") &*a#t
#ypes of conventional power plant2
%. Hydro power plant
&. Steam power plant
(. uclear power plant*. !as turbine power plant
#ypes of non3conventional power plant2
%. #idal power plant
&. 4ind power plant
(. !eothermal power plant
*. Solar power plant
,. 4ave power plant
5. "HD !eneration
6 Lit th" th")!a* &'(") &*a#t i# Ta!i*#a4/
Alathiur 6&7%8"49/ #amilnadu/ "adras cements
)nnore 6&75:"4/(7%%:"49 #amilnadu )lectricity ;oard
eyveli 657,:"4/&7%::"49 #amilnadu eyveli lignite corp +t
What i th" 4" ', 4)3" ta#7+
#he surge tank is used to provide better regulation of water pressure in the system. #he surge tank
controls the water when the load on the turbine decreases and supplies water when the load on the
turbine increases. #hus/ surge tank controls the pressure variations resulting from the rapid
changes in water flow in penstock and hence prevents water hammer
8 E9&*ai# a$'4t &"#t'.7+
#he pipe between surge tank and prime mover is known as penstock.
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12 What i th" ,4#.ti'# ', .''*i#3 %t"! i# Di""* &'(") &*a#t+
#he function of cooling system is to remove heat from the engine cylinder to keep the
temperature of the cylinder in low range and e$tend engine life.
1 What i th" &4)&'" ', i#t").''*") i# 3a t4)$i#" &'(") &*a#t+
Since the power required to compress the air is less in isothermal process it is required to
maintain the/ temperature of air constant as far as possible. Hence the air leaving the +.P.
compressor is cooled by intercooler and then passed to the H.P compressor.
1 Na!" i!&')ta#t hi3h &)"4)" $'i*")+
+a "ont boiler
;enson boiler
+offler boiler
=elo$ boiler.
15 What i th" !ai# &4)&'" ', hi3h-&)"4)" $'i*")+
#he high3pressure boilers are used to increase the efficiency of the plant and to
reduce the cost of electricity production.
16 What a)" th" a4!&ti'# !a" ,') ai) ta#a) .%.*" a#a*%i+
#he working medium is a perfect gas throughout
#he working medium Does not undergo any chemical change throughout cycle.
#he compression and e$pansion process are reversible adiabatic.
#he operation of the engine is friction less
1 What i th" ,4#.ti'# ', ".'#'!i;")+
>eed water from the feed tank is supplied to the economi0er by feed pump. #he economi0er is
used to preheat the water before it goes the boiler. #here is a heat e$changer from the hot gases
to the feed water
18
D)a( th" P-< a# T-S ia3)a! ', th" B)a%t'# .%.*"/
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1: E9&*ai# )"-h"at .%.*"/
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5. #ehri Dam/ Uttranchal/ %::: "4
26 What a)" th" ""#tia* "*"!"#t ', h%)' &'(") &*a#t+
%. 'atchment area
&. eservation
(. Dam
*. Surge tanks
,. Draft tubes
5. Power house
. Switched for transmission of power
2 What i !"a#t $% .at.h!"#t a)"a a# "9&*ai# it ,4#.ti'#=
#he whole area behind the dam is called the catchment area. #he rain water in the area will
be drained into the dam through a dam or river.
28 E9&*ai# R"")'i)=
A reservoir may be natural/ like a lake on a mountain or artificially built by erecting a dam
across a river.
2: D",i#" 4)3" ta#7=
A Surge tank is a small reservoir in which the water level rises swings during -pening and
closing of inlet valve.
0 What i a !i#i a# !i.)' >%)' &*a#t+
#he mini power plants operate with ,m3&:m head and produce about % "4 to ,"4 of
power.
#he micro power plants require a head less than ,m and produce :.% "4 to %
1 What i !"a#t $% &)'&"**") t4)$i#"+
#he basic propeller turbine consists of a propeller.
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#he pitch of the propeller blades together with wicket gate ad1ustment enables easonable
efficiency to be maintained under part flow conditions. Such turbines are
'alled as ?aplan turbines D",i#" t(i# )4##")=
#wo runners can be placed on the same shaft either side by side or on opposite Sides of the
generator. #his configuration is unusual and would only be used if the umber of 1ets per runner
had ma$imi0ed.8 Stat" th" aa#ta3" ', i!&4*" t4)$i#" '") )"a.ti'# t4)$i#"=
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( Wh% th" &)"&a)ati'# ', .'a* i #"."a)%+
#he coal from coal nines cannot be directly fed into the furnace. Proper preparation of coal
should be done before feeding the coal to the furnace. light conveyors.
#he coal transfer starts by carrying of coal from unloading point to the storage site.
, W)it" a$'4t .*ai,i.ati'# ', )a43ht+
Draught is classified as
%. atural draught
&. Artificial draught
#he artificial draught is further classified as
6a9 Steam 1et draught
6b9 "echanical draught
6c9 orced draught
5 D",i#" th" t")! Nat4)a* )a43ht a# (hat a)" th" aa#ta3" ', #at4)a* )a43ht %t"!+
#he tall chimney creates the natural draught by the temperature difference between hot
gases in the chimney and cold atmospheric air outside the chimney.#he advantages are
o e$ternal power is required
Air pollution is less since gases are discharged at high level.
o maintenance cost
'apital cost is less than artificial draught.
W)it" a$'4t a)ti,i.ia* )a43ht+
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Pressure throughout the system is above atmospheric pressure so the air leakage into the
furnace is reduced.
%: What i th" 4" ', &4*")i") a# #a!" i,,")"#t t%&" ', &4*")ii#3 !i**+
#he pulveriser is used to pulveri0e the coal in order to increase the surface e$posure. Pulveri0ed
coal enables rapid combustion. #he different types of pulveri0ing mills are
%. ;all mill
&. Hammer mill
(. ;all and race mill.
%% >'( th" ah ha#*i#3 %t"! i .*ai,i"+
%. "echanical handling system
&. Hydraulic system(. Pneumatic system
*. Steam 1et system
%& Na!" i,,")"#t t%&" ', 4t .'**".t')+
%. "echanical Dust collector
!ravitational separators
;ag house dust collector
#here are three types of bag house dust collector
-pen pressure type
'losed pressure type
'losed suction type
&. 'yclone. Separators
(. )lector Static Precipitator 6)SP9
%( What i th" !ai# &4)&'" ', .hi!#"%+
#he main purpose of chimney is to emit the flue gases at a considerable height to avoid nuisance
to the surrounding people.
%* / D",i#" ,')." )a,t a# i#4." )a,t .''*i#3 t'(")
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i. #he outlet water comes in contact with the driest air and warmest water comes in contact
with most humid air.
ii. #he re3circulation is seldom a problem.
iii. #he first cost is low due to the reduction in pump power consumption.
%5 What i th" (')7i#3 &)i#.i&*" ', C''*i#3 T'(")+
#he hot water is sprayed from the top of the tower/ while the air is made to flow from the bottom of
the tower to the top. #his air cools the hot water in the cooling tower. Air vapori0es a small
percentage of water/ there by cooling the remaining water. #he air absorbs the heat and leaves at
the top of the tower and cooled water leaves at the bottom and recalculated to the condenser.
% What a)" th" ,a.t') that a,,".t th" )at" ', "a&')ati'# ', (at") i# .''*i#3 t'(")+ A!'4#t', (at") 4),a." a)"a "9&'"
#he time of e$posure
#he relative velocity of air passing over the droplets
#he H of air
#he direction of airflow relative to water
%8 Na!" i,,")"#t t%&" ', .''*i#3 t'(")+
#he cooling towers are classified as follows.
6a9 According to the construction of material
%. #imber 3 for small tower
&. >erro concrete 3 for large capacity stations.
(. "ulti deck concrete towers 3 for large steam stations
*. "etallic
6b9 According to the nature of air draught3
%. Atmospheric 6or9 atural draught cooling system
&. "echanical draught cooling tower.
%@ >'( th" at!'&h")i. @') #at4)a* )a43ht .''*i#3 t'(")- a)" .*ai,i"+
'( !".ha#i.a* )a,t .''*i#3 t'(") a)" .*ai,i"+
"echanical draft cooling tower is classified into three types
%. >orced draft tower.
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&.
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UNIT III
NUCLEAR AND >YDEL POWER PLANT
% D",i#" N4.*"a) ii'#/
An atomCs nucleus can be split apart. 4hen this is done a tremendous amount of energy is
released. #he energy is both heat and light energy. #his energy/ when let out slowly can be
harnessed to generate electricity.
& D",i#" N4.*"a) 4i'#/
>usion means 1oining smaller nuclei to make a larger nucleus. #he sun uses nuclear fusion of
hydrogen atoms into helium atoms. #his gives off heat and other radiation.( Na!" th" i,,")"#t .'!&'#"#t ', #4.*"a) )"a.t')+
%. uclear fuel &. "oderator (. 'ontrol rods *. eflectors
,. eactor vessel 5. ;iological shielding . 'oolant
* What i th" &4)&'" ', )"&)'."i#3 ', #4.*"a) (at"+
#he used fuel contains @5E uranium/%E plutonium and (E radioactive wastes. eprocessing
is used to separate the waste from the uranium and plutonium which can be recycled into new fuel.
#he reprocessing effectively reduces the volume of waste and limits the need to mine new supplies
of uranium/ so that e$tending the time of resources.
, What i N"4t)'# *i," ti!"+
#he prompt neutron lifetime/ is the average time between the emission of neutrons and either
their absorption in the system or their escape from the system. #he term lifetime is used because
the emission of a neutron is often considered its birth/ and the subsequent absorption is considered
its death.
5 What i U)a#i4!-25 .hai# R"a.t')+
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uranium atoms splitting those. #hose particles given off split still other atoms in a chain reaction. ;9
,. High temperature !as cooled reactors6H#!'9
%( What a)" &)"4)i;" (at") )"a.t') @PWR+
#he P4 belongs to the light water type. #he moderator and the coolant are both light water
6H&-9. #he cooling water circulates in two loops/ which are fully separated from one another. P4
keep water under pressure/ so the water heats but does not boil even at the high operating
temperature.
%* What i $'i*i#3 (at") )"a.t') @BWR+
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the water boils away in the reactor pressure vessel/ thus a mi$ture of water and steam leaves the
reactor core.
%, What i M'*t"# Sa*t R"a.t') @MSR+
A molten salt reactor is a type of nuclear reactor where the primary coolant is a molten salt.
"olten salt refers to a salt that is in the liquid phase that is normally a solid at standard temperature
ionic liquid/ although technically molten salts are a class of ionic liquids.
%5 N4.*"a) P'(") &*a#t a,"t%/
adiation doses can be controlled through the following procedures2
%.#he handling of equipment via remote in the core of the reactor
&. Physical shielding
(. +imit on the time a worker spends in areas with significant radiation levels
*. "onitoring of individual doses and of the working environment
,. Safety mechanism of a uclear power reactor
% Lit th" N4.*"a) &'(") &*a#t i# I#ia/
%. ?aiga6(7&&"4PH49/ ?arnataka
&. ?akrapar 6&7&&"4PH49/ !u1arat
(. ?udankulam 6&7%::"4P49/ #amilnadu
*. "adras 6&7%"4PH49/ #amilnadu
%8 D",i#" !"a# 3"#")ati'# ti!"/
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UNIT Ile$ibility in operation
*. 'apability to quick start
,. High efficiency etc../
& +ist the ma1or components of gas turbine.
%.'ompressor
&. 'ombustion chamber and
(. #urbine
( +ist the types of gas turbine power plants.
%.-pen cycle gas turbine power plant
&. 'losed cycle gas turbine power plant* +ist the disadvantages of gas turbine power plant.
%.o load and Partial load efficiency is low
&.High sensitive to component efficiency
(.#he efficiency depends on ambient pressure and ambient temperature
*. High air rate is required to limit the ma$imum inlet air temperature. Hence e$haust
losses are high
,. Air and gas filter is required to prevent dust into the combustion chambers.
, Define regenerator efficiency.
#he regenerator efficiency is defined as2GActual temperature rise of air "a$imum temperature rise possible
5 .+ist the factors which affect the performance of gas turbine power plants.
%. Part load efficiency
&. >uel consumption
(. Air mass flow rate
*. #hermal efficiency
,. egeneration
4hat are the working fluids in gas turbineB
%.Air
&.Helium
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(.Argon
*.'arbon dio$ide
8 +ist the various types of diesel plants.
;ased on number of strokes2
6a9 #wo stroke diesel engine
6b9 >our stroke diesel engine
;ased on orientation2
6a9 Hori0ontal diesel engine
6b9 =ertical diesel engine
;ased on number of cylinders2
6a9 single cylinder
6b9 "ulti cylinder
And other type like naturally aspirated/ superheated etc./
@ +ist the components of diesel power plant.
%.Diesel engine
&. Air intake system
(. )$haust system
*. >uel system
,. 'ooling system
5. +ubricating system
. Starting of engine
%: +ist the various functions of fuel in1ection system.%.
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%( 4hat are the methods of cooling system usedB
%. Air cooling
&. 4ater cooling
%* +ist the methods adopted for circulating the water in a cooling system.
%. #hermosipon cooling
&. >orced cooling by pump
(. #hermostat cooling
*. Pressuri0ed water cooling
,. )vaporative cooling
%, 4hat are the important functions of a lubricating systemB
%. +ubricating
&. 'ooling
(. 'leaning
*. Sealing
,. oise absorption
%5 +ist the various types of lubricating system used in diesel engine.
%. "ist lubricating system
&. 4et sump lubrication system
(. Dry sump lubrication system
% 4hat are the starting methods of diesel engineB
%. ;y an au$iliary engine
&. ;y an electric motor
(. ;y compressed air
%8 +ist any four advantages of diesel power plant.
%.
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*. Used as emergency plant
&% Define mean effective pressure as applied to gas power cycles. How it is related to indicated power
of an
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% What a)" th" .'!&'#"#t ', '*a) "#")3%+
%. %.'ollector&. Storage unit
& D",i#" "!a# ,a.t')+
Demand factor is defined as the ratio of ma$imum demand to connected load.
'onnected load is the sum of ratings in k4 of equipment installed in the consumers
premises.
"a$imum demand is the ma$imum load/ which a consumer uses at any time.
( D",i#" *'a .4)"+
+oad curve is a graphical representation between load in k4 and time in hours. i$ed cost includes the following cost.
%. 'ost of land &. 'ost of building
(. 'ost of equipment *. 'ost of installati5n
,.
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8 What i th" #"" ', "&)".iati'# .'t+
Depreciation cost is the amount to be set aside per year from the income of the plant to
meet the depreciation caused by the age of service/ wear and tear of the machinery and
equipments. Depreciation amount collected every year helps in replacing and repairing the
equipment.
@ What i .'#."#t)ati'# )ati'+
'oncentration ratio is defined as the ratio between the aperture area and the receiver
Absorber area of the collector.
%: Lit th" a)i'4 t%&" ', '*a) "#")3% .'**".t')/
%.Stationary collectors 6or9 on3 concentrating
6a9 >late plate collectors
6b9 'ompound parabolic collectors
6c9 )vaculated tube collectors
&.Sun tracking concentrating collector
6a9 single a$is tracking
6b9 #wo3a$is tracking
%% Lit a#% ,'4) a&&*i.ati'# ', '*a) .'**".t')/
%.Solar water heating
&. Solar space heating systems
(. Solar refrigeration
*.
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*.#he plant requires little maintenance or help after setup
,. loating plant
%5 Lit th" .*ai,i.ati'# ', OTEC $a" '# .%.*"/
%.-pen cycle
&.'losed cycle
(.Hybrid cycle
% Lit a#% ,'4) iaa#ta3" ', OTEC/
%. Degradation of heat e$changer performance as dissolved gases.
&. Degradation of heat e$changer performance by microbial fouling
(.
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&% W)it" '(# th" a)i'4 t%&" ', (i# &'(") &*a#t/
%.emote
&.Hybrid
(.!rid connected
&& Lit a#% ,'4) aa#ta3" ', (i# t4)$i#"/
%.
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&@ What a)" th" !ai# &a)t ', 3"'th")!a* &'(") &*a#t+
%.Production well
&.=apori0er
(.'irculating pump
*.)$pansion turbine,.!enerator
5.'ondenser
.#ransformer
(: What a)" th" .*ai,i.ati'# ', 3"'th")!a* "#")3% .'#")i'# %t"!+
%.Single cycle geothermal power plant
&.;inary cycle power plant
(% What a)" th" aa#ta3" ', 3"'th")!a* "#")3%+
%.'heaper
&.=ersatile in its use
(.Delivers greater amount of energy
(& What a)" th" iaa#ta3" ', 3"'th")!a* "#")3%+
%. Drilling operation is noisy
&. D %t"!+
%.-pen cycle systems
&. 'losed cycle systems
6a9 Seeded inert gas systems
6b9+iquid metal systems
(* What a)" th" aa#ta3" ', M>D %t"!+
%. +arge amount of power is generated
&. o moving parts/ so more reliable.
(.'losed cycle system produces power/ free of pollution
*. Ability to reach its full power as soon as started.(, Lit th" .*ai,i.ati'# ', 'i* i#".ti'# %t"!/
6a9 'ommon rail in1ection system
6b9
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magnetic field.
( What a)" th" a&&*i.ati'# ', 3"'th")!a* "#")3%+
%.!eneration of electric power
&.Space heating for building
(.