paper 2 set-a - key

8/11/2019 Paper 2 Set-A - key

1/23

Paper 2 Set A Key

Regn No: _________________

Name: ___________________

(To be written by the candidate)

12thNATIONAL CERTIFICATION EXAMINATIONFOR

ENERGY MANAGERS & ENERGY AUDITORS Ot!"er# 2$11

PAPER 2% Eer'y E(())ey ) Ther*a+ Ut)+)t)e,

Date% 1-.1$.2$11 T)*)',% 1/%$$ 0 1%$$ RS D3rat)!% 4 RS Ma5. Mar6,% 1-$

Set)! 0 I% O78ECTI9E TYPE Mar6,% -$ 5 1 : -$

(i) Answer all -$questions(ii) Each question carries !emark(iii) Please hatch the aroriate o!al in the "#R answer sheet with $lack Pen or %$

encil& as er instructions

' The density o a substance relati!e to water is called

a) !iscosity b) seciic gra!ity c) dew oint d) our oint

* +hich o the ollowing is not a unit o !iscosity

a) Engler b) Rankine c) ,aybolt d) Redwood

- The amount o heat required to raise the temerature o ' kg o a substance by 'o. iscalled

a) sensible heat b) latent heat c) seciic heat d) net caloriic !alue

/ +hich among the ollowing uels is likely to contain ma0imum ercentage o sulhur1

a) kerosene b) diesel oil c) 2,%, d) urnace oil

3 +hich o the ollowing grades o 4ndian coal will ha!e the highest caloriic !alue1

a) $ b) 5 c) A d) E

6 +hich o the ollowing is not measured in ro0imate analysis1

a) !olatile matter b) i0ed carbon c) sulhur d) ash

7 +hich o the ollowing is not measured in the ultimate analysis o a uel 1

'_______________________$ureau o Energy Eiciency


2/23

Paper 2 Set A Key

a) o0ygen b) i0ed carbon c) sulhur d) nitrogen

8 .aret loss is associated with

a) combustion o coal b) storage o coal c) combustion o oil d) storage o natural gas

9 +hich o the ollowing is not true with resect to imroer siing o coal

a) results in oor combustion b) lower e0cess air resulting in lesser stack lossc) increase o unburnts in ash d) lower thermal eiciency

'; +hich o the ollowing uel constituents releases ma0imum amount o heat er kg duringcombustion 1

a) hydrogen b) carbon c) sulhur d) nitrogen

'' +hich is the statement that is true o a ire tube boiler

a) has a single steam drum b) ire is in the tubesc) water in the tubes d) has multile steam drums

'* .oal is not burnt in susension in

a) luidised bed boiler b) chain o steam?water mi0ture 1

a) the temerature at critical oint is -7/'3o.

b) the ressure at critical oint is **'* bar

c) saturated liquid and saturated !aour lines meet at critical oint

d) enthaly o e!aoration is ma0imum at critical oint

'7 The head loss due to riction in a ie is

a) directly roortional to the diameter b) directly roortional to the gra!itational constantc) in!ersely roortional to the !elocity d) directly roortional to the square o !elocity

*_______________________$ureau o Energy Eiciency


3/23

Paper 2 Set A Key

'8 ,elect the wrong statement with resect to steam tras

a) discharges condensate as soon as it is ormedb) does not allow steam to escaec) caable o discharging air and other incondensable gasesd) does not allow condensate to escae

'9 %eat transer in a urnace is eected by

a) radiation rom lame b) radiation rom urnace wallsc) con!ection due to mo!ement o hot gases o!er the stock d) all o the abo!e

*; 4n a coke ired cuola&carbon mono0ide is roduced in the

a) reheating one b) reducing onec) combustion one d) melting one

*' 4n an oil ired heat treatment urnace which o the ollowing is not required to determine itseiciency by direct method

a) weight o inut material b) o0ygen ercentage in lue gasc) uel consumtion d) caloriic !alue o uel

** +hich o the ollowing may not hel in energy eicient urnace oeration1

a) maintaining a ositi!e drat inside the urnaceb) minimiing reractory lossesc) comlete combustion with ma0imum e0cess aird) use o ceramic ibre in batch tye urnace

*- ,elect the wrong statement with resect to urnace oerations

a) the burner lame should not touch the stockb) air iniltration leads to o0idation o billetsc) ceramic ibre linings are used in the e0terior o the urnaced) heat loss through oenings is roortional to T/

*/ The eecti!eness o a heat e0changer does not deend on

a) seciic heat o hot luid b) 4nlet temerature o hot luidc) 2#T@ d) 4nlet temerature o cold luid

-_______________________$ureau o Energy Eiciency


4/23

Paper 2 Set A Key

*3 Pinch analysis uses the _____ law o thermodynamics

a) 5irst b) ,econd c)Third d) $oth (a) (b)

*6 4n a counter


5/23

Paper 2 Set A Key

-7 ____ indicates the sotening temerature o the reractory

a) reractoriness under load (RD2) b) cold crushing strengthc) yrometric cone equi!alent (P.E) d) orosity

-8 An increase in bulk density o a reractory increases its

a) !olume stability b) heat caacity c) resistance to slag enetration d) all o the abo!e

-9 The insulation material used or medium temerature alication is

a) calcium silicate b) olyurethane c) wood d) mica

/; A coal ired 5$. boiler can oerate at ___ e0cess air

a) - / C b) *;


6/23

Paper 2 Set A Key

Set)! 0 I% O78ECTI9E TYPE Mar6,% -$ 5 1 : -$

(i!) Answer all -$questions(!) Each question carries !emark(!i) Please hatch the aroriate o!al in the "#R answer sheet with $lack Pen or %$

encil& as er instructions

3' The density o a substance relati!e to water is called

a) !iscosity b) seciic gra!ity c) dew oint d) our oint

3* +hich o the ollowing is not a unit o !iscosity

a) Engler b) Rankine c) ,aybolt d) Redwood

3- The amount o heat required to raise the temerature o ' kg o a substance by 'o. iscalled

a) sensible heat b) latent heat c) seciic heat d) net caloriic !alue3/ +hich among the ollowing uels is likely to contain ma0imum ercentage o sulhur1

a) kerosene b) diesel oil c) 2,%, d) urnace oil

33 +hich o the ollowing grades o 4ndian coal will ha!e the highest caloriic !alue1

a) $ b) 5 c) A d) E

36 +hich o the ollowing is not measured in ro0imate analysis1

a) !olatile matter b) i0ed carbon c) sulhur d) ash

37 +hich o the ollowing is not measured in the ultimate analysis o a uel 1

a) o0ygen b) i0ed carbon c) sulhur d) nitrogen

38 .aret loss is associated with

a) combustion o coal b) storage o coal c) combustion o oil d) storage o natural gas

39 +hich o the ollowing is not true with resect to imroer siing o coal

a) results in oor combustion b) lower e0cess air resulting in lesser stack lossc) increase o unburnts in ash d) lower thermal eiciency

6; +hich o the ollowing uel constituents releases ma0imum amount o heat er kg duringcombustion 1

a) hydrogen b) carbon c) sulhur d) nitrogen

6' +hich is the statement that is true o a ire tube boiler

a) has a single steam drum b) ire is in the tubesc) water in the tubes d) has multile steam drums

6_______________________$ureau o Energy Eiciency


7/23

Paper 2 Set A Key

6* .oal is not burnt in susension in

a) luidised bed boiler b) chain1

a) caloriic !alue o uel b) latent heat o steam c) uel quantity d) all o the abo!e

6/ +hen solutions o diering concentrations are searated by a semi o steam?water mi0ture 1

a) the temerature at critical oint is -7/'3o.

b) the ressure at critical oint is **'* bar

c) saturated liquid and saturated !aour lines meet at critical oint

d) enthaly o e!aoration is ma0imum at critical oint

67 The head loss due to riction in a ie is

a) directly roortional to the diameter b) directly roortional to the gra!itational constant

c) in!ersely roortional to the !elocity d) directly roortional to the square o !elocity

68 ,elect the wrong statement with resect to steam tras

a) discharges condensate as soon as it is ormedb) does not allow steam to escaec) caable o discharging air and other incondensable gasesd) does not allow condensate to escae

69 %eat transer in a urnace is eected by

a) radiation rom lame b) radiation rom urnace wallsc) con!ection due to mo!ement o hot gases o!er the stock d) all o the abo!e

7; 4n a coke ired cuola&carbon mono0ide is roduced in the

a) reheating one b) reducing onec) combustion one d) melting one

7' 4n an oil ired heat treatment urnace which o the ollowing is not required to determine itseiciency by direct method



8/23

Paper 2 Set A Key

a) weight o inut material b) o0ygen ercentage in lue gasc) uel consumtion d) caloriic !alue o uel

7* +hich o the ollowing may not hel in energy eicient urnace oeration1

a) maintaining a ositi!e drat inside the urnace

b) minimiing reractory lossesc) comlete combustion with ma0imum e0cess aird) use o ceramic ibre in batch tye urnace

7- ,elect the wrong statement with resect to urnace oerations

a) the burner lame should not touch the stockb) air iniltration leads to o0idation o billetsc) ceramic ibre linings are used in the e0terior o the urnaced) heat loss through oenings is roortional to T/

7/ The eecti!eness o a heat e0changer does not deend on

a) seciic heat o hot luid b) 4nlet temerature o hot luidc) 2#T@ d) 4nlet temerature o cold luid



9/23

Paper 2 Set A Key

73 Pinch analysis uses the _____ law o thermodynamics

a) 5irst b) ,econd c)Third d) $oth (a) (b)

76 4n a counter


10/23

Paper 2 Set A Key

87 ____ indicates the sotening temerature o the reractory

a) reractoriness under load (RD2) b) cold crushing strengthc) yrometric cone equi!alent (P.E) d) orosity

88 An increase in bulk density o a reractory increases its

a) !olume stability b) heat caacity c) resistance to slag enetration d) all o the abo!e

89 The insulation material used or medium temerature alication is

a) calcium silicate b) olyurethane c) wood d) mica

9; A coal ired 5$. boiler can oerate at ___ e0cess air

a) - / C b) *;


11/23

Paper 2 Set A Key

Set)! II% SORT DESCRIPTI9E ;UESTIONS Mar6,% < 5 - : /$

(i) Answer all E)'htquestions(ii) Each question carries F)=e marks

S01 The ,pe)()at)! !( (3rae !)+ (r!* +a" aa+y,), ), ')=e "e+!>#

Car"! %


12/23

Paper 2 Set A Key

Ans Absorbed heat in thermic luid G m H . H del T

Absorbed heat in thermic luid G (';; H 8*;) H ;33 H *;

Absorbed heat in thermic luid G $2$$$ Ka+hr

Thermal eiciency o the heater G absorbed duty ? heat duty

#ass o coal required G absorbed duty ? (eiciency H caloriic !alue o coal)

#ass o coal required G 9;*;;; ? (;63 H /*;;)

#ass o coal required :44$./6'hr

S04 A heat e5ha'er ), t! "e @e,)'e@ t! !@e,e a =ap!3r at the rate !(


13/23


14/23

Paper 2 Set A Key

8No clinker ormation

92ess e0cess air

';,imle oeration& quick startu

''5ast resonse to load luctuations

'*No soot blowing

'-Pro!ision o automatic coal and ash handling systems

'/Pro!ision o automatic ignition system

'3%igh reliability

'6Reduced maintenance

'7Luick resonse to changing demand

'8%igh eiciency o ower generation

S0 a Bhy ,tea* ), *!,t pre(erre@ heat)' *e@)a ) pr!e,, )@3,tr)e,H

" Bhy ,at3rate@ ,tea* ), pre(erre@ !=er ,3perheate@ !r >et ,tea* (!r )@)retheat)' ) a pr!e,,H

ANS,team is most reerred or ollowing reasons

Kery high heat content

Mi!es u heat at constant temerature

Produced rom water (chea& lentiul)

.lean& odorless& tasteless

4t>s heat can be used o!er and o!er

.an generate ower& then used or heating

.an be readily distributed& easily controlled

,aturated steam has a high heat transer coeicient 4t immediately releases the latentheat on contacting the cold surace ,o heat transer is aster and at uniormtemerature ,uerheated steam has a low heat transer coeicient and irst it has togi!e u it suerheat which haens slowly and then once it reaches the saturation stateit gi!es u the latent heat ,o it takes more time to heat with suerheated steam %encesaturated steam is reerred

S0ater te*perat3re ),/$C. GC9 !( (3e+ ), 1$$$$ 6Ca+6' a@ e(())ey !( the "!)+er ),


17/23

Paper 2 Set A Key

Fee@ >ater te*perat3re % -$ C

Stea* etha+py % $ 6Ca+6'

Stea* Sat3rat)! te*perat3re % 1$ C

GC9 !( (3e+ !)+ % --$ 6Ca+6'

C!,3*pt)! !( (3e+ !)+ % 4$$ 6'hr

Ca+3+ate the "!)+er e(())ey )( the @rye,, (rat)! ), $.


18/23

Paper 2 Set A Key

L04 I a r3@e @),t)++at)! 3)t !( a re()ery# -$ Metr)T!ehr !( r3@e ), heate@ 3,)',at3rate@ ,tea* ) a heat e5ha'er (r!* 4-C t! ! ,tea* hea@er, !perat)' at 4 "ar a@ < "ar re,pet)=e+y# pa,,)' ear"y theheat e5ha'er. C!,t !( ,tea* ), ,a*e (!r "!th 4 "ar a@ < "ar R,./.-$6'

A, a Eer'y Maa'er# >h)h !( the (!++!>)' !pt)!, >)++ y!3 re!**e@ t! the3)t "a,e@ ! the a3a+ !,t !( ,tea*H

a Ut)+),)' 4 "ar ,tea*

" Ut)+),)' < "ar ,tea*

G)=e% Data (r!* ,tea* ta"+e%

Stea*Pre,,3re#

"ar

Etha+py 6Ca+6'

Bater E=ap!rat)! Stea*

4.$ 144 -1 -$


19/23

Paper 2 Set A Key

L0/ Ma6e a )++3,trat)=e ,6eth !( the (!++!>)',

a ,)*p+e "a6 pre,,3re t3r")e

" @!3"+e e5trat)! "a6 pre,,3re t3r")e

@!3"+e e5trat)! !@e,)' t3r")e

@ 'a, t3r")e !*")e@ y+e

ANS

a) b) (c)

d)

L0- I a !3ter (+!> heat e5ha'er# >ater ), "e)' h)++e@ "y ,!@)3* h+!r)@e "r)e.The rate !( (+!> !( the "r)e ), 2. 6', a@ that !( the >ater ), 1.-< 6',. E,t)*ate

'9_______________________$ureau o Energy Eiciency


20/23

Paper 2 Set A Key

the te*perat3re t! >h)h the >ater ), !!+e@ )( the "r)e eter, at < C a@ +ea=e,at 1$ C# a@ )( the >ater eter, the e5ha'er at 4< C. Ca+3+ate the area !( theheat e5ha'er ,3r(ae )( the !=era++ heat tra,(er !0e(())et ), 1$$ 8*2,C.C!,)@er the ,pe)() heat !( "r)e a@ >ater ), 4.4< & /.1< 686'C re,pet)=e+y.

ANS %eat gain by brine G heat lost by water

*7 H --8 H (';


21/23

Paper 2 Set A Key

ANS a Re3)re*et, !( re(rat!ry *ater)a+

a) Ability to withstand high temperatures.

b) Ability to withstand sudden changes o temperatures.

c) Ability to withstand action o molten metal slag! glass! hot gases! etc.

d) Ability to withstand load at ser"ice conditions.e) Ability to withstand load and abrasi"e orces.

) #ow coeicient o thermal e$pansion.g) %hould be able to conser"e heat.

h) %hould not contaminate the material with which it comes into contact.

b)Tube ailures can be attributed to design& manuacturing& oerational& maintenance andageing related asects The tube ailures mechanisms can be classiied as #echanical&chemical& metallurgical in adequate quality comliance

Meha)a+ a3,e,

#echanical damage o tubes takes lace due to ly ash erosion& steam imingement romsoot blowers& alling clinker and uel articles The #echanical damage increases thestress le!el leading to tube ailure

Che*)a+ a3,e,

+ater side and ire side corrosion ailure o tubes occurs due to henomenon like causticgouging& hydrogen embrittlement& itting& and stress corrosion cracking while ire sidecorrosion is oten due to high as well as low temerature eects

Meta++3r')a+ a3,e,

4n high tem comonents like suerheaters& reheaters cree damage occurs due too!erheating wherein the tube material loses its strength and ailure occurs by stressruture +eld Ooint ailures by cracking and atigue ailures by !ibration& thermal andcorrosion henomenon are other reasons or metallurgical related tube ailures

;3a+)ty a,,3rae 'ap,

Tube ailures are also known to occur due to inadequate quality assurance roceduresduring design?manuacturing o boiler tubes @ue care during material rocurement&adotion o healthy abrication ractices& good oeration and maintenance ractices intube manuacturing would hel to minimie tube leakages and achie!e high a!ailability

Ther*!!*pre,,!r

*'_______________________$ureau o Energy Eiciency


22/23

Paper 2 Set A Key

4n many o the steam utiliation equiment wherecondensate comes out at high ressure& a maOorortion o it lashes into low ressure steam whichgoes wasted Dsing a thermocomressor it becomeseasible to comress this low ressure steam by high

ressure steam and reuse it as a medium ressuresteam in the rocess The maOor energy in steam is inits latent heat !alue and thus thermocomressingwould gi!e a large imro!ement in waste heatreco!ery

Thermocomressors are designed to accurately mi0lower


23/23

Paper 2 Set A Key

The %eat Pie comrises o three elements a sealed container& a caillary wick structureand a working luid The caillary wick structure is integrally abricated into the interior

surace o the container tube and sealed under !acuum Thermal energy alied to thee0ternal surace o the heat ie is in equilibrium with its own !aour as the container tubeis sealed under !acuum Thermal energy alied to the e0ternal surace o the heat iecauses the working luid near the surace to e!aorate instantaneously Kaour thusormed absorbs the latent heat o !aourisation and this art o the heat ie becomes ane!aorator region The !aour then tra!els to the other end the ie where the thermalenergy is remo!ed causing the !aour to condense into liquid again& thereby gi!ing u thelatent heat o the condensation This art o the heat ie works as the condenser regionThe condensed liquid then lows back to the e!aorated region A igure o %eat ie isshown in 5igure

-------- End of Section - III ---------

*-

paper 2 set-a - key

Documents