GLOBALI NSTI TUTE OFENGI NEERI NG & TECHN HNOLOGY MEL VI SHARAM 6325 09 ME6301ENGI NEERI NG THERMO MODYNAMI MI CS I I ISEME MESTER MECHANI CALAND AUTOMOBI LEENGI NEERI NG
UNIT-1 BASIC CONCEPT & FIRST LAW PART-A
1. Write Write down the the equation equation for first first law law for a steady steady flow process process.. (Apr/May (Apr/May 16) 2. Give Give the the ener enery y equat equatio ion n appli applica ca!l !lee for for an adia adia!at !atic ic no"" no""le le and an adia adia!a !ati ticc tur!i tur!ine ne.. (Apr/May 16) #. $how how "eroth "eroth law of ther%ody ther%odyna%ics na%ics is is used for te%perat te%perature ure %easure%ent %easure%ent.(&ov/ .(&ov/'ec 'ec 1) . $how that the the enery enery of an isolated isolated syste% syste% re%ains re%ains constant. constant. (&ov/'e (&ov/'ecc 1) . $tate the the first first law for a closed syste% syste% undero underoin in a process process and a cycle. cycle. (Apr/May (Apr/May 1) 1) 6. Why does does free free e*pansion e*pansion have "ero "ero wor+ transfer, transfer, (Apr/M (Apr/May ay 1) -. What is "eroth "eroth law of of ther%ody ther%odyna%ics na%ics,, (&ov/'ec (&ov/'ec 1) . o%pare o%pare heat transfer transfer with with wor+ wor+ transf transfer. er. (&ov/'ec (&ov/'ec 1) 0. 'efine 'efine her%o her%odyna%i dyna%icc quili quili!riu% !riu%.. (May/3 (May/3une une 1) 14. 'ifferentiate !etween 5oint function and 5ath function. (May/3une (May/3une 1) 11. What is %icroscopic approach in ther%odyna%ics, (&ov/'ec1#) 12. 'efine e*tensive property. (&ov/'ec1#) 1#. 'efine 'efine ontinuu%. ontinuu%. (May/3une (May/3une 1#) 1. 'ifferentiate !etween heat and te%perature. (May/3une (May/3une 1#) 1. 'istinuish !etween Macroscopic and Macroscopic enery. enery. (&ov/'ec 2412) 16. 'efine quasistatic quasistatic process. (May/3une 12) (&ov/'ec 12) 1-. What is 5MM 1, Why it is i%possi!le, (May/3une 12) 1. 'istinuish !etween the ter%s 7state8 and 7processes of ther%odyna%ics. (&ov/'ec 2411) 10. $how that enery of an isolated isolated syste% is always always constant. (&ov/'ec 2411) 2411)
PART-B 1. A %ass of air is initially initially at 264 9 and and -44 +5a: +5a: and occupies occupies 4.42 4.42 %#.he air is e*panded at constant pressure to 4.4 %#. A polytrophic process with n ; 1. is then carried out followed !y a constant te%perature process which co%pletes a cycle. All the process are reversi!le. (1)$+etch the cycle in $ and 5< planes (2) =ind the heat received and heat re>ected in the cycle.? (#) .=in@ the efficiency of the cycle. (Apr/May 16) 2. A roo% roo% for four person person has 2 fans fans :each consu%in consu%in 4.1 +W power: power: and and three 144 W la%ps. la%ps.
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#. (i) A %ass %ass of as as is co%press co%pressed ed in a quasi quasi static static process process fro% fro% 4 B5a: 4.1% 4.1% to # 1.# 4.4M5a:4.4# % .assu%in that the pressure and the te%perature are related !y 5< ;:
5redict the wor+ done !y the as syste%. (ii) A %il+ chillin unit can re%ove heat fro% the %il+ at the rate of 1.-M3/hr. Ceat lea+s into the %il+ fro% the surroundin at an averae rate of .1-M3/hr. =ind the D
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te%perature required for coolin a !atch of 44 B of %il+ fro% to . a+e p of %il+ to !e .1-B3/+ B. (&ov/'ec 241 . (i) Write the steady flow enery equation for a !oiler. (&ov/'ec 241) (ii) Air flows steadily at the rate of 4.4 +/s throuh an air co%pressor: enterin at 6 %/s with a pressure of !ar and a specific volu%e of 4. %#/+ and leavin at . %/s with a pressure of 6.0 !ar and a specific volu%e of 4.16 %#/+. he internal enery of the air leavin is +3/+ reater than that of enterin air. oolin water surroundin the cylinder a!sor!s heat fro% the air at the rate of 0 W. alculate the power required to drive the co%pressor and the inlet and outlet crosssectional areas. (&ov/'ec 241) . A tur!ine operatin under steady flow conditions receives stea% at the followin stateE pressure 1#. !ar: specific volu%e 4.1# % /+: internal enery 204 B3/B: velocity #4 %/s. he state of the strea% leavin tur!ine is tur!ine isF pressure 4.# !ar: specific volu%e .#-% /B: internal enery 2#64 B3/B: velocity 04 %/s. Ceat is lost to the surroundins at the rate of 4.2 B/s. f the rate of stea% flow is 4.# B/s: what is the power developed !y the tur!ine, (May/3une 241) #
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6. A as underoes a ther%odyna%ic cycle consistin of the followin processes # (i) 5rocess 12E constant pressure 51;1. !ar: <1; 4.42% : W12;14.+3 (ii) 5rocess 2#E co%pression with 5<;: #;2 (iii)5rocess #1E constant volu%e: 1# ; 26.+3. here are no sinificant chanes in the B and 5. 1) $+etch the cycle on a 5< diara%. 2) alculate the networ+ for the cycle in +3. #) alculate the heat transfer for the process 12. ) $how that the su% of heat transfer in the cycle is equal to the su% of wor+ transfer in the cycle. E (May/3une 241) D
-. hree ra%s of nitroen as at 6 at%. and 164 in a frictionless piston cylinder device is e*panded adia!atically to dou!le its initial volu%e: then co%pressed at constant pressure to its initial volu%e and then co%pressed aain at constant volu%e to its initial state. alculate the net wor+ done on the as. 'raw the 5< diara% for the processes. (&ov/'ec 1) . 04B3 of heat is supplied to a syste% at constant volu%e. he syste% re>ects 0B3 of heat at constant pressure and 1 B3 of wor+ is done on it. he syste% is !rouht to its oriinal state !y adia!atic process. 'eter%ineF (i) he adia!atic wor+ (ii) he values of internal enery at all states if initial value is 14 +3 (&ov/'ec 1)H 0. 'eter%ine the heat transfer and its direction for a syste% in which a perfect as havin D the %olecular weiht of 6 is co%pressed fro% 141.# B5a: 24 to a pressure of 644 B5a 1.# followin the law p< ; .a+e spe cif ic he at at constant pressure of a as is 1.-+3/BB. (May/3une 1) D
14. n a as tur!ine installation air is heated inside the heat e*chaner up to -4 fro% the
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a%!ient te%perature of2- . hot air then enters into the as tur!ine with a velocity of 4 D %/s and leaves at 644 . Air leavin the tur!ine enters a no""le a t 64%/s velocity and D leaves the no""le at the te%perature of 44 . for unit %ass of the flow rate of air: *a%ine the followin assu%in the adia!atic e*pansion in the tur!ine and no""le. I# (i) Ceat transfer to air in heat e*chaner (ii) 5ower output fro% tur!ine (iii)
(&ov/'ec 241#) () () ()
1#. A three process cycle operatin with nitroen as as the wor+in su!stance has constant D
te%perature co%pression at # with the initial pressure 144B5a. hen the as underoes a constant volu%e heatin and then polytropic e*pansion with1.# as inde* of co%pression. he isother%al co%pression requires 6- B3/B of wor+. 5oint out (i) 5: <@ around the cycle. (ii) Ceat in and out (iii)&et wor+ =or &itroen as v ; 4.-#1B3/B B. (May/3une 1#) 1. 5rove that enery is a property of a syste% and also e*plain the li%itations of first law of ther%odyna%ics. (May/3une 1#) 1. A as of %ass 1. + underoes a quasistatic e*pansion: which follows a relationship 5;aK!<: where 7a8 and 7!8 are constants. he initial and final pressures are 1444 +5a and 244 +5a respectively and the correspondin volu%es are 4.2 %# and 1.2 %# . he specific internal enery of the as is iven !y the relation ; (1.5< L ) +3/+: where 5 is in +5a and < is in %# . alculate the net heat transfer and the %a*i%u% internal enery of the as attained durin e*pansion. (&ov/'ec 12) UNIT-2 SECOND LAW AND AVAILABILITY ANALYSIS PART-A
1. A reversi!le heat enine operates !etween a source at 44 9 and a sin+ at #4 9. What is the least rate of heat re>ection per BW networ+ output of the enine,(May/3un16) 2. 'efine rreversi!ility. (May/3un16) #. What a r e the c au se s o f irreversi!ility, . What i s entropy principle, . What is ther%al enery reservoir, *plain the ter% source and sin+.
6. What is reversed heat enine, -. $tate +elvin 5lanc+8s second law state%ent. . What is the entropy principle, 0. Write arnot theore% and its corollaries. 14. Write the applications of reversed carnot cycle. 11. What is the difference !etween adia!atic and isentropic process, 12. $tate lausius state%ent. 1#. 'raw a sche%atic of an heat pu%p. 1. Give the conditions for reversi!ility. 1. What is %eant !y dead state,
(&ov/'ec1) (&ov/'ec1)
(May/3un1) (May/3un1) (&ov/'ec1) (&ov/'ec1) (May/3un1) (May/3un1#) (May/3un1#) (&ov/'ec1#) (&ov/'ec1#) (May/3un12)
16. Give the e*pressions for the ther%al efficiency of a heat enine and the ..5.
of a heat pu%p. 1-. With s diara% find the isother%al heat addition process.
(May/3un12) (&ov/'ec12) 1. n an isother%al process 1444 +3 of wor+ is done !y the syste% at a te%perature of 2449. What is the entropy chane of this process, (&ov/'ec12) 10. 5oint out the purpose of second law of ther%odyna%ics. 24. What is the difference !etween Nefrierator and heat pu%p, PART –B
1. A heat enine operatin !etween two reservoirs at 1444 + and #44+ is used to drive a heat pu%p which e*tracts heat fro% the reservoir at #44 + at aO rate twice that at which the enine re>ects heat to it. f the efficiency of the enine is 4Pof the %a*i%u% possi!le and the cop of the heat pu%p is 4P of the %a*i%u% possi!le: what is the te%perature of the reservoir to which the heat pu%p re>ects heat , What is the rate of heat re>ection fro% the heat pu%p if the rate of heat supply to the enine is 4 +W, (Apr/May 16) 2. 4 + of water is at #1# B and enouh ice at 9 is %i*ed with water in an adia!atic vessel such that at the end of the process all the ice %elts and water at 4 9 is o!tained. =ind the %ass of ice required and the entropy chane of water and ice. Given 5 of water ; .2 +3/+B: 5 of ice ; 2.1 B3/++ and latent heat of ice; ## +3/+. (Apr/May 16) #. (i) What i s a reversed carnot heat e n i n e , (ii)A heat pu%p wor+in on a reversed carnot cycle ta+es in enery fro% a reservoir %aintained delivers .it to another reservoir where at #9 and te%perature is --9 . he heat pu%p drives p o w e r for its ope rat ion fro% a reversi!le heat enine operatin within the hiher and lower te%perature li%its of 14--9 and --9 . =or 100 kJ/s of enery supplied to the reservoir at --9: esti%ate the enery ta+en fro% the reservoir at 14--9. (&ov/'ec1)
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A fluid underoes a reversi!le adia!atic co%pression fro% 4. M5a: 4.2 % to # 1.# 4.4% : accordin to the law 5< ;. deter%ine the chane in enthalpy and entropy and (&ov/'ec1) the heat transfer and wor+ transfer durin the process. D
. (i) A reversi!le heat pu%p is used to %aintain a te%perature of 4 in a refrierator when it D
re>ects the heat to the surroundins at 2 . if the heat re%oval rate fro% the refrierator is 14+3/%in: deter%ine the 5 of the %achine and the wor+ input required. (ii) f the required input to run the pu%p is developed !y a reversi!le enine which D
receives heat at #4 and re>ects heat to the at%osphere and then deter%ines the overall 5 of the syste%. (May/3un1) #
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6. % of air at 2 !ar: 2- is co%pressed up to 6 !ar pressure followin 5< ;. it is su!sequently e*panded adia!atically to 2 !ar. onsiderin the two processes to !e reversi!le deter%ine the networ+: net heat transfer: and chane in entropy. Also plot the process on 5< and $ diara%. (May/3un1)
7. (i) wo arnot enines A and I are operated in series. he first one receives heat at D
-4 and re>ects to a reservoir at . I receives heat re>ected !y the first enine and in turn re>ects to a sin+ #44 B. calculate the te%perature for
(i) qual wor+ output of !oth enines (ii) $a%e efficiencies (iii)Mention lausius inequality for open: closed and isolated syste%s. (&ov/'ec 241#) D
. # B of air at 44 B5a: 04 e*pands adia!atically in a closed syste% until its volu%e is dou!led and its te%perature !eco%es equal to that of the surroundins at 144B5a and D 14 . calculate the %a*i%u% wor+: chane in availa!ility and irreversi!ility. (ii) Iriefly discuss a!out the concept of entropy. (&ov/'ec 241#) D
0. A reversi!le heat enine operates !etween two reservoirs a te%perature of 644 and D 4 . the enine drives a reversi!le refrierator which operates !etween the reservoirs at D D te%peratures of 4 and 24 . the heat transfer to the heat enine is 2444 B3 and the networ+ output for the co%!ined enine refrierator is #4 B3. valuate the heat transfer D to the refrierant and the net heat transfer to the reservoir at 4 . (May/3une 241#) D
14. (i) Celiu% enters an actual tur!ine at #44B5a and e*pands to 144 B5a: 14 . Ceat D
transfer to at%osphere at 141.#2B5a: 2 a%ounts to -B3/B. alculate the enterin strea% availa!ility: leavin strea% availa!ility and the %a*i%u% wor+. =or heliu%: p;.2 B3/B and %olecular weiht; .44#B/B%ol. (ii) Qist out and e*plain various caused of irreversi!ility. (May/3une 241#) 11. (i) n a arnot cycle the %a*i%u% pressure and te%perature are li%ited to 1 !ar and 149. he volu%e ratio of isentropic co%pression is 6 and isother%al e*pansion is 1.. Assu%e the volu%e of the air at the !einnin of isother%al e*pansion as 4.1 %#. $how the cycle on p< and s diara%s and deter%ine (1) he pressure and te%perature at %ain points (2) her%al efficiency of the cycle. (ii) 'efine the reversi!le and irreversi!le process. (&ov/'ec 2412) 12. (i) $tate and prove lausius inequality. (ii)A %etal !loc+ with % +: c 4. +3/+.B at 49 is +ept in a roo% at 249. t is cooled in the followin two waysE (1) sin a arnot enine (e*ecutin interal nu%!er of cycles) with the roo% itself as the cold reservoirF (2) &aturally. (&ov/'ec 2412) 1#. A arnot enine delivers 144 +W of power !y operatin !etween te%perature reservoirs at 144deree and 1444 deree . alculate the entropy chane of each reservoir and the net entropy chane of the two reservoirs after 24 %in of operation. (May/3un 2412) 1. (i) 1244B3 of heat is supplied to an enine fro% a source of 24 R: the sin+ te%perature is 2 R. Which of the followin cycle represents reversi!le: irreversi!le or i%possi!le cycle, (1) 2- B3 heat is re>ected to sin+ (2) 2 B3 heat is re>ected (#) #4B3 heat is re>ected. (ii) $how that Belvin5lanc+ state%ent of the second law i%plies a violation of the lausius state%ent. (May/3un 2412) 1. A heat pu%p wor+in on the carnot cycle ta+es in heat fro% a reservoir at R and delivers heat to a reservoir at 64R. the heat pu%p is driven !y a reversi!le heat enine which ta+es heat fro% reservoir at 4R and re>ect heat to a reservoir at 64R. the reversi!le heat enine also drives a %achine that a!sor!s #4BW. f heat pu%p e*tract 1-B3/$ec fro% the
reservoir at R(&ov/'ec 11) 3.PROPERTIES OF PURE UBSTANCE AND STEAM POWER CYCLE
PART –A
1. $tate the phase rule for pure su!stance. (May/3une 16) 2. Mention the two wor+in fluids used in !inary vapour cycle. (May/3une 16) #. What is nor%al !oilin point, (&ov/'ec 1) . When is reheat reco%%ended in a stea% power plant, (&ov/'ec 1) . What is %eant !y ?dryness fraction of stea%?, (May/3un 1) 6. 'raw the standard Nan+ine cycle on 5v and s coordinates.(May/3un1) -. 'ifference !etween the flow and nonflow process. (&ov/'ec 1) . Write the %ethods of i%provin Nan+ine cycle. (&ov/'ec 1) 0. 'raw the 5 diara% for water and la!el all salient points. (May/3une 1) 14. Give the possi!le ways to increase ther%al efficiency of Nan+ine cycle. (May/3une 1) 11. $+etch the Nan+ine ycle s diara% and indicate the all process on it (&ov/'ec1#) 12. 'efine a pure su!stance. (&ov/'ec1#) 1#. 'efine triple point. (May/3une 1#) 1. $tate dryness fraction. (May/3une 1#) 1. 'efine deree of superheat. (May/3une 12) 16. 'raw the 5 diara% for pure su!stances. (May/3une 12) 1-. 'ifference !etween the flow and nonflow process. (&ov/'ec 12) 1. $+etch the Nan+ine ycle s diara% and indicate the all process on it. (May/3une 11) 10. $uperheated stea% at #4 !ar and #44D enters a tur!ine and e*panded to !ar and quality 4.0- dryness: co%pute the loss in availa!ility for the adia!atic process if the at%ospheric te%perature is 2-4 D. (May/3une 11) 20. alculate the %ass of 4.- %# of wet stea% at 14D and 04P dry. (&ov/'ec 11)
PART –B
1. A lare insulated vessel is divided into two cha%!ers: one containin . + of dry saturated stea% at 4.2 M5a and the other 14 + of stea%: 4. quality at4. M5a. f the partition !etween the cha%!ers is re%oved and the $tea% is %i*ed thorouhly and allowed to settle: find the final pressure: stea% quality and entropy chane in the process. (May/3une 16) 2. n a stea% power plant the condition of stea% at inlet to the stea% tur!ine is 24 !ar and #44 9 and the condenser pressure is 4.1 !ar. wo feed water heaters operate at opti%u% te%peratures. 'eter%ineE (1) he quality of stea% at tur!ine e*haust: (2) networ+ per + of stea%: (#) cycle efficiency: () the stea% rate. &elect pu%p wor+. (May/3une 16) #. $tea% at 04 !ar and 49 is supplied to a stea% tur!ine. he stea% is reheated to its oriinal te%perature !y passin the stea% throuh reheater at 12 !ar. he e*pansion after reheatin ta+es place to condenser pressure of 4.4- !ar. =ind the efficiency of the reheat cycle and wor+ output if the flow of stea% is +/sec. &elect the pressure loss in the syste% and assu%e e*pansions throuh the tur!ine are isentropic. 'o not nelect pu%p wor+. (&ov/'ec 1) . (i)'iscuss the different "ones of < diara% for water when the te%perature rises fro% 249 to 2449 at 1 at% pressure (ii) A vessel of volu%e 4.4 %# contains a %i*ture of saturated water and saturatedstea% at a te%perature of 249. he %ass of the liquid present is 0 +. =ind the pressure: %ass: specific volu%e: enthalpy: entropy and the internal enery. (&ov/'ec 1)
. A vessel of volu%e 4.4 % contains a %i*ture of saturated water and saturated stea% at a te%perature of 249. he %ass of the liquid present is 0 +. =ind the pressure: the %ass: the specific volu%e: theenthalpy: and entropy: and the internal enery of the %i*ture. (May/3une 1) 6. A stea% power plant operates on a si%ple ideal Nan+ine cycle !etween the pressure li%its of # M5a and 4 +5a. he te%perature of the stea% at the tur!ine inlet is #44 and the %ass flow rate of stea% throuh the cycle is # +/s. $how the cycle on a s diara% with respect to saturation lines and deter%ine a) the ther%al efficiency of the cycle and !) the net power output of the power plant. (May/3une 1)
-. *plain the stea% for%ation with relevant s+etch and la!el all salient points and e*plain
every point in detail. (&ov/'ec 1) . n a Nan+ine ycle: the stea% at inlet to the tur!ine is saturated at a pressure of # !ar and the e*haust pressure is 4.2 !ar. 'eter%ine (&ov/'ec 1) (i) he pu%p wor+ () (ii) he tur!ine wor+ () (iii)he condenser heat flow () (iv)he dryness at the end of e*pansion. Assu%e flow rate of 0.+/s. () #
0. A vessel havin a capacity of 4.4% contains a %i*ture of saturated water and saturated D
stea% at a te%perature of 2 . the %ass of the liquid present is 14 B. alculate the pressure: %ass: specific volu%e: specific enthalpy: specific entropy: and specific internal enery. (May/3une 1) 14. A stea% power plant operates on a theoretical reheat cycle. $tea% at !oiler at 14 !ar: 49 e*pands throuh the hih pressure tur!ine. t is reheated at a constant pressure of 4 !ar to 49 and e*pands throuh the low pressure tur!ine to a condenser at 4.1 !ar. 'raw s and hs diara%s. =indE (i) Juality of stea% at tur!ine e*haust (ii) ycle efficiency (iii) $tea% rate in +/+Wh. (May/3une 1) D
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11. $tea% at 4 : 04 !ar is supplied to a Nan+ine cycle. t is reheated to 12 !ar and 4 . the %ini%u% pressure is 4.4- !ar. alculate the wor+ output and the cycle efficiency usin stea% ta!les with and without considerin the pu%p wor+. (&ov/'ec 1#) D
12. (i)$tea% initially at 4.#M5a: 24 is cooled at constant volu%e. At what te%perature D will the stea% !eco%es saturated vapour, What is the stea% quality at 4 . also find D D what is the heat transferred per + of stea% in coolin fro% 24 to 4 . (ii)When will u call a vapour superheated, Give e*a%ples. Also when will you call a liquid as co%pressed liquid, Give e*a%ples. (&ov/'ec 1#)
1#. n an Nan+ine cycle uses stea% at 24 !ar: #649 which is e*panded in a stea% tur!ine to 4.4 !arE =ind the Nan+ine cycle efficiency. (May/3une 1#) 1. $tea% enters the tur!ine at #M5a and 449 and is condensed at 14B5a. $o%e quality of stea% leaves the tur!ine at 4.6M5a and enters open feed water heater. o%pute the fraction of the stea% e*tracted per + of stea% and cycle ther%al efficiency. (&ov/'ec 12)
1. n a reheat cycle : the initial stea% pressure and the %a*i%u% te%perature are 14 !ar and 4 derees celcius respectively . if the condenser pressure is 4.1 !ar and the %oisture at the condenser inlet is 1P : and assu%in ideal processes : detr%ine(a) the reheat pressure: (!) the cycle eeficiency: and (c) the stea% rate (May/3une 12) 4.IDEAL AND REAL GASES, TERMODYNAMIC RELATIONS PART-A
1. What are reduced properties, Give their sinificance, (May/3un16) 2. What is the i%portance of 3ouleho%son coefficient , (May/3un16) #. Why do the specific heats of an ideal as depend only on the ato%ic structure of the as, (&ov/'ec1) . 'efine volu%e e*pansivity. (&ov/'ec1) . What is 3ouleho%son coefficient, Why is it "ero for an ideal as, (May/3un1) (May/3un1) 6. What is the law of correspondin states, -. What are the properties of ideal as, (&ov/'ec1) . $tate the
1. A vessel of volu%e 4.2 %# contains 14 + of air at #24 B. 'eter%ine the pressure e*erted !y the air usin a) perfect as equation !)
and volu%e are . B: 2.-# M5a and 4.416%#/B %ol. Neadin fro% a co%pressi!ility chart for a reduced pressure of 1.#: the co%pressi!ility factor S is 4.-. What are the correspondin specific volu%e: pressure: te%perature and reduced volu%e, (&ov/'ec 1) . 'erive any three Ma*well relations.
(May/3une 1) #
6. 'eter%ine the pressure of nitroen as at ;1- B and v ; 4.44#-% /B on the !asis of a. he ideal as equation of state. !. he van der Walls equation of state. c. he van der Walls constant for nitroen areT;4.1-%6B5a/BF !;4.441#%#/B (May/3une 1)
-. *plain the irreversi!ility with respect to flow and nonflow process. *plain the effectiveness of the syste%. $tate the %ain reason for Neal as !ehavior. (&ov/'ec 1) . he pressure and te%perature of %i*ture of + of 2 and 6 + of &2 and !ar and 2-Drespectively. =or the %i*ture deter%ine the followinF a) he %ole fraction of each co%ponent !) he averae %olecular weiht c) he specific as constant d) he volu%e and density e) he partial pressure and partial volu%e. (May/3un1) 0.
(i) 'erive the lausius lapeyron equation and discuss its sinificance. (ii) Write down two ds relation.
10.
11.
(&ov/'ec 1#)
'raw a neat $che%atic of a o%pressi!ility chart and indicate .
(&ov/'ec 1#)
(i) 'erive lausius lapeyron equation. What are the assu%ptions %ade in this equation, # (ii) onsider an ideal as at #4# B and 4.6% /B. As a result of so%e distur!ance the #
state of as chanes to #4 B and 4.-% /B. sti%ate the chane in pressure of the as as the result of this distur!ance. (May/3un 1#) 12.
=ro% the !asic principles: prove the followin pv ;
validity of Ma*well8s relation
and verify the
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for stea% at #44 and 44 B5a. (M ay /3 un 1# )
1#.(i)An insulated riid tan+ is divided into two co%part%ents !y a partition: ne co%part%ent contains - + of o*yen as at 49 and 144 +5a: and the other co%part%ent contains + of nitroen as at 249 and 14 +5a. &ow the partition is re%oved: and the two ases are allowed to %i*. 'eter%ine (a) the %i*ture te%perature and ( b) the %i*ture pressure after equili!riu% has !een esta!lished. (ii) *plain the physical sinificance of the co%pressi!ility factor S. (&ov/'ec 12) 1. 'erive the 3oule ho%son coefficient. 1. *plain and derive lausius lapeyron equation.
(&ov/'ec 12) (May/3une 12)
!.GAS MI"TURES AND PSYCROMETRY
PART –A
1. $tate 'alton?s law of partial pressure. n what assu%ptions this law is !ased, (May/3un 16) 2. What is adia!atic %i*in and write the equation for that, (May/3un 16) #. 'efine dew point te%perature. (&ov/'ec1) . What i s che%ical dehu%idification, (&ov/'ec1) (May/3un 1) . What is A%aat?s law, (May/3un 1) 6. What is sensi!le heatin, -. 'efine %olar %ass. (&ov/'ec1) . 'efine $ensi!le heat factor. (&ov/'ec1) (May/3un 1) 0. 'efineE Adia!atic saturation te%perature. 14. What is !ypass factor, (May/3un 1) 11. 'efine 'eree of saturation. (&ov/'ec1#) 12. Why do wet clothes dry in the sun faster, (&ov/'ec1#) 1#. &a%e any two adsor!ents used in che%ical dehu%idification. (May/3un1#) 1. What is adia!atic evaporative coolin, (&ov/'ec12) 1. What is the relative hu%idity of air if the '5 and 'I are 29 and #44 at 1 at%ospheric pressure, (&ov/'ec12) 16. 'ifferentiate !etween relative and specific hu%idity. (May/3un 12) 1-. 'efine psychro%etry. (&ov/'ec11) 1. $tate the effects of very hih and a very low !ypass factor. (&ov/'ec11) 10. What is need of slin psychro%eter, (May/3un11) 24. What are the assu%ptions %ade while %i*in two air strea%s, (May/3un11) PART –B #
1. A riid tan+ of % contains as %i*ture co%prisin # + of4 2: + of &2 and + of 42 at 204 B. alculate the %olar specific volu%e: initial pressure of the as. f it is heated to #4 B: calculate the heat transfer and chane in enthalpy. Also verify the Gi!!s theore% for entropy. (May/3un 16) 2. A roo% -%U%U% is occupied !y an airwater vapour %i*ture at # 9. he at%ospheric pressure is 1 !ar and the relative hu%idity is -4P. 'eter%ine the hu%idity ratio: dew point: %ass of dry air and %ass of water vapour. f the %i*ture of airwater vapour is further cooled at constant pressure until the te%perature is 149. =ind the a%ount of water vapour condensed. (May/3un 16) D
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#. (i) he slin psychro%eter reads 4 'I and 2 WI: alculate specific hu%idity: relative hu%idity: vapour density in air: dew point te%perature and enthalpy of the %i*ture per + of dry air: assu%e at%ospheric pressure to !e 1.4# !ar. (ii)What is wet !ul! depression and where it is equal to "ero, (&ov/'ec 1)
. (i) *plain adia!atic evaporative coolin. D
(&ov/'ec 1) D
(ii) Air at 24 : 4P relative hu%idity is %i*ed adia!atically with air at 4 : 4P relative hu%idity in the ratio of 1 B of the for%er with 2 B of the latter (on dry !asis). =ind the condition of air. D
. A as %i*ture consists of - B of nitroen and # + of o*yen at !ar and 2- . calculate the %ole fraction: partial pressures: %olar %ass: as constant: volu%e and density. (May/3un 1) 6. At%ospheric air at 1.41#2 !ar has a 'I of #4D and WI of 2D. o%pute i. he partial pressure of the water vapour ii. $pecific hu%idity iii. 'ew point te%perature iv. Nelative hu%idity v. 'eree of saturation vi. 'ensity of air in the %i*ture
vii. 'ensity of vapour in the %i*ture viii. nthalpy of the %i*ture (use ther%odyna%ics ta!le only). (May/3un 1) -. A %i*ture of hydroen and o*yen is to !e %ade so that the ratio of C2 and 2 is 2E1 !y D volu%e. f the pressure and te%perature of 1 !ar and 2 respectively: calculate (i) he %ass of 2 required. (ii) he volu%e of the container. (&ov/'ec 1) #
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. 124 % of air per %inute at # 'I and 4P relative hu%idity is cooled to 24 'I !y passin throuh coolin coil. 'eter%ine the followin (&ov/'ec 1) (i) Nelative hu%idity of out co%in air and its WI. (ii) apacity of coolin coils in tones of refrieration. (iii)A%ount of water vapour re%oved per hour. D
0. (i) An air water vapour %i*ture enters an air conditionin unit at pressure of 1.4 !ar # 'I: and a relative hu%idity of -P. he %ass of d ry air enterin is 1B/s. he airvapour D %i*ture leaves the air conditionin unit at 1 !ar: 1 : P relative hu%idity. he %oisture D condensed leaves at 1 . (ii) 'eter%ine the heat transfer rate for the process. (May/3une 1) 14. t is required to desin an air conditionin syste% for an industrial process for the followin hot and wet su%%er conditions D
utdoor conditions
E #2 'I and 6 D
Nequired air inlet conditions E 2 'I and 64P NC # A%ount of free air circulated E 24 % /%in D
oil dew te%perature E 1# he required conditions are achieved !y first coolin and dehu%idifyin and then !y heatin. alculate the followin (!y psycho%etric chart) (i) he coolin capacity of the coolin coil and its !ypass factor. (ii) Ceatin capacity of the heatin coil in +W and surface te%perature of the heatin coil if the !ypass factor is 4.# (iii)he %ass of the water vapour re%oved per hour. (May/3une 1) 11. (i) *plain adia!atic evaporative coolin. D
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(ii) Air at 24 : 4P relative hu%idity is %i*ed adia!atically with air at 4 : 4P relative hu%idity in the ratio of 1 B of the for%er with 2 B of the latter (on dry !asis). =ind the condition of air. (&ov/'ec 1#) 12. 'efine the ter%s of Nelative hu%idity and $pecific hu%idity and also e*plain the adia!atic saturation process with a sche%atic. (&ov/'ec 1#) 1#. (i) 'erive the sensi!le heat factor for coolin and dehu%idification process. Also e*plain the process. D D D (ii) ne + of air at 4 'I and 4P NC is %i*ed with 2 B of air at 24 'I and 24 dew point te%perature. alculate the te%perature and specific hu%idity of the %i*ture. (May/3un 1#) 1. (i) 5rove that specific hu%idity of air is ;4.622 1#) (ii) With the aid of %odel psychro%etric chart e*plain the followin process (i) Adia!atic %i*in
(May/3un
(ii) vaporative coolin 1. At%ospheric air at 1.41#2!ar at 24o 'I and 6P NC. =ind the hu%idity ratio: wet !ul! te%perature: dew point te%perature: derees of saturation: enthalpy of the %i*ture and density of air and density of water vapour in the %i*ture. (&ov/'ec 12)
