UNIVERSITI TEKNOLOGI MARA FAKULTI KEJURUTERAAN KIMIA CHEMICAL ENGINEERING LABORATORY 2 (CHE 523) NAME /STUDENT NO. GROU$ E%$ERIMENT DATE $ERFORMED DATE RE$ORT SUBMITTED SEMESTER LECTURER
No. 1 2 ! 5 $ * , 1' 11 12 1
Title Abstract/Summary Introduction Aims T"eory A##aratus Met"odoloy/&rocedure esults +alculations -iscussion +onclusion ecommendations eerence / A##endi Su#er0isor s radin TTA3 MA4S
C*+,-: C*0*1 :
C+,*+,
: : : : : : :
SITI AQUILAH SALIM (2!"3##!#5) (2!"3##!#5 ) EH223A SHELL AND TUBE 2" MARCH 2!& # A$RIL 2!& 3 NORHASLINA CHE RAD'I
Allocated Marks (%) 5 5 5 5 5 1' 1' 1' 2' 5 5 5 1' 1''
Marks
+NT6NT A@STA+T INT-<+TIN T67 @6+TIB6 A&&AT
&A?6S
A-,4, S"ell and Tube eat 6c"aner is t"e most common ty#e o "eat ec"aner in industrial a##lications suc" in "eatin or coolin #rocess luids and ases (7unus A.+enel). T"e ob8ecti0es o t"is e#eriment is to e0aluate and study t"e "eat balance9 3MT- and o0erall "eat transer coeicient9 to calculate eynoldss number at t"e s"ell and tube "eat ec"aner9 to study t"e :orkin #rinci#le o counter lo: "eat ec"aner9 to study t"e eect o luid lo: rated on "eat ec"aner ec"aner #erormance. #erormance. T"e a##aratus t"at "as been used in order to run t"is e#eriment is t"e S3T6; eat 6c"aner Study T bet:een t"e "ot and cold luids is lare at t"e inlet o t"e "eat ec"aner ec"aner but decreases at t"e outlet. In conclusion9 s"ell and tube "eat ec"aner ollo:s t"e basic la: o T"ermodynamics and all t"e aims in t"is e#eriment "ad been ac"ie0ed.
I+,416,7+
A "eat ec"ane ec"anerr is a de0ice de0ice t"at allo:s "eat "eat rom rom a luid (a liEuid or a as) to #ass to a second luid (anot"er liEuid or as) :it"out t"e t:o luids "a0in to mi toet"er or come into direct contact. I t"atFs not com#letely clear9 consider t"is. In t"eory9 :e could et t"e "eat rom t"e as 8ets 8ust by t"ro:in cold :ater onto t"em9 but t"en t"e lames :ould o outG outG T"e T"e essen essenti tial al #rin #rinci ci#l #lee o a "eat "eat ec" ec"an ane err is t"at t"at it trans transer erss t"e t"e "eat "eat :it" :it"ou outt transerrin t"e luid t"at carries t"e "eat.
Ciure 1 = o: "eat ec"aner :ork eat eat ec"an ec"aner er usual usually ly used used or or all kinds kinds o #lace #laces9 s9 usual usually ly :orki :orkin n to "eat "eat or or cool cool buildins or "el#in enines and mac"ines to :ork more eiciently. erierators erierators and and airH conditioners99 or eam#le9 use "eat ec"aners in t"e o##osite :ay rom central "eatin conditioners systems= t"ey remo0e "eat rom a com#artment or room :"ere itFs not :anted and #um# it a:ay in a luid to some ot"er #lace :"ere it can be dum#ed out o t"e :ay. In #o:er In #o:er #lants or #lants or enines enines99 e"aust ases oten contain "eat t"atFs "eadin uselessly a:ay into t"e o#en air. T"atFs a :aste o enery and somet"in a "eat ec"aner can certainly reduce (t"ou" not eliminate entirelysome "eat is al:ays oin to be lost). T"e :ay to sol0e sol0e t"is t"is #roble #roblem m is :it" :it" "eat "eat ec"an ec"aner erss #ositio #ositioned ned inside t"e e"aus e"austt tail #i#es or smokestacks. As t"e "ot e"aust ases drit u#:ard9 t"ey brus" #ast co##er ins ins :it" :ater lo:in t"rou" t"em. T"e :ater carries t"e "eat a:ay a:a y9 back into t"e #lant. T"ere9 it i t mi"t be recycled directlyJ maybe :armin t"e cold ases t"at eed into t"e enine or urnace9 sa0in t"e enery t"at :ould ot"er:ise be needed to "eat t"em u#. r it could be #ut to some ot"er ood use9 or eam#le9 "eatin an oice near t"e smokestack (+"ris Ko Koodird odird 9 2'1$)
There There are are many many types types of heat heat exchang exchanger er and some of them them are are shell shell and tube heat exchangers, plate heat exchangers and regenerative heat exchang exchanger. er. Shell and tube heat exchang exchangers ers are comprised comprised of multiple multiple tubes through which liquid ows. The tubes are divided into two sets: the rst rst set set cont contai ains ns the the liqu liquid id to be heat heated ed or cool cooled ed.. The The seco second nd set set contai contains ns the liquid liquid respo responsi nsible ble for trigge triggerin ring g the heat heat excha exchange nge,, and eith either er remov emoves es heat heat from from the the rst rst set set of tube tubes s by abso absorb rbin ing g and and transmitting heat awayin essence, cooling the liquidor warms the set by transmitting its own heat to the liquid inside. !hen designing this type of exchanger, care must be ta"en in determining the correct tube wall thic"ness as thic"ness as well as tube diameter, to allow optimum heat exchange. #n
terms of ow, shell and tube heat exchangers can assume any of three ow path patterns. $late heat exchangers consist of thin plates %oined together, with a small amount of space between each plate, typically maintained by a small rubb rubber er gas" gas"et et.. The The su surf rfac ace e area area is lar large, ge, and and the the cor corners ners of each each rectangular plate feature an opening through which uid can ow between plates, extracting heat from the plates as it ows. The uid channels themselves alternate hot and cold uids, meaning that heat exchangers can can e&ec e&ecttivel ively y cool cool as well well as heat heat uid uidthey they are are often ten used sed in refriger refrigeration ation applications. applications. 'ecause 'ecause plate heat exchang exchangers ers have such a large surface area, they are often more e&ective than shell and tube heat exchangers #n a regene regenerativ rative e heat excha exchanger, nger, the same same uid uid is passed passed along both sides of the exchanger, which can be either a plate heat exchanger or a shell and tube heat exchanger. 'ecause the uid can get very hot, the exit exitin ing g uid uid is us used ed to war warm the the inco incomi ming ng uid uid,, main mainta tain inin ing g a near near constant temperature. ( large amount of energy is saved in a regenerative heat heat exch exchan ange gerr beca becaus use e the the proc proces ess s is cycl cyclic ical al,, with with almost all relative heat being transferred from the exiting uid to the incoming uid. To maintain a constant temperature, only a little extra ener energy gy is need eed to raise aise and and low lower the the over verall all uid uid tempe emperratur ature e )Thomas*et, )Thomas*et, +- Cor t"is t"is e#e e#erime riment9 nt9 counte counterHc rHcurre urrent nt "eat ec"an ec"aner er is used. used. In counte counterr lo: lo: "eat "eat ec"aners9 t"e t:o luids lo: aainst eac" ot"er9 maintainin a maimum tem#erature dierence bet:een t"e "ot and cold streams :"ic" allo:s or maimum "eat transer. Ciure 2 s"o:s "o: t"e counterHcurrent "eat ec"aner :orks
Ciure 2 = T"e T"e lo: o "ot L cold :ater in counterHcurrent counterHcurrent "eat ec"aner
O8*,79*-
1
To e0al e0aluat uatee and and study study t"e t"e "eat "eat balan balance9 ce9 3MT3MT- and and o0e o0eral ralll "ea "eatt tran transe serr coe coe ici icien ent. t.
2
To calc calcul ulat atee ey eyno nold lds sss num numbe berr at at t"e t"e s"el s"elll and and tub tubee "ea "eatt ec ec"a "an ner er
To stud study y t"e t"e :ork :orkin in #ri #rinc nci# i#le le o coun counte terr lo lo: : "ea "eatt ec ec"a "an ner er..
!
To stu study dy t"e t"e e eec ectt o o lui luid d lo lo: : rat rated ed on "eat "eat ec ec"a "an ner er #er #ero orm rman ance ce..
T*4 T"e eneral unction o a "eat ec"aner is to transer "eat rom one luid to anot"er. T"e basic com#onent o a "eat ec"aner can be 0ie:ed as a tube :it" one luid runnin t"rou" it and anot"er luid lo:in by on t"e outside. T"ere are t"us t"ree "eat transer o#erations t"at need to be described= 1. +on0ecti0e +on0ecti0e "eat "eat transer transer rom luid to t"e inner inner :all :all o t"e t"e tube9 tube9 2. +onducti0e +onducti0e "eat transer transer t"rou" t"rou" t"e tube tube :all9 and . +on0ecti0e +on0ecti0e "eat "eat transer transer rom t"e outer outer tube tube :all to to t"e outsid outsidee luid. luid. eat eat ec" ec"an ane ers rs are are ty#i ty#ical cally ly class classii iied ed acco accord rdin in to lo: lo: arran arrane eme ment nt and and ty#e ty#e o construction. T"e sim#lest "eat ec"aner is one or :"ic" t"e "ot and cold luids mo0e in t"e same or o##osite directions in a concentric tube (or doubleH#i#e) construction. In t"e #arallelHlo: arranement o Ciure (a) (a)99 t"e "ot and cold luids enter at t"e same end9 lo: in t"e same direction9 and lea0e at t"e same end. In t"e counter lo: arranement o Ciure (b) (b)99 t"e luids enter at o##osite ends9 lo: in o##osite directions9 and lea0e at o##osite ends (&ro. . S. S#ako0sky 9nd)
O&arallel lo:P
O+ounterlo:P Ciure = +oncentric tubes "eat ec"aners In t"is e#eriment9 e#eriment9 students students conduct conduct t"is e#eriment e#eriment usin usin counter counter current current lo: o s"ell s"ell and tube "eat ec"aner. T"e tube side is used or t"e luid t"at is more likely to oul t"e
:alls9 or more corrosi0e9 or or t"e luid :it" t"e "i"er #ressure (less costly). +leanin o t"e inside o t"e tubes is easier t"an cleanin t"e outside. K"en a as or 0a#or is used as a "eat ec"ane luid9 it is ty#ically ty#ically introduced on t"e s"ell side. Also9 "i" 0iscosity liEuids9 liEuids9 or :"ic" t"e #ressure dro# or lo: t"rou" t"e tubes mi"t be #ro"ibiti0ely lare9 can be introduced on t"e s"ell side. 2 T"e most common material o construction is carbon steel. t"er materials suc" as stainless steel or co##er are used :"en needed9 and t"e c"oice is dictated by corrosion concerns as :ell as mec"anical strent" reEuirements. 6#ansion 8oints are used to accommodate accommodate dierential dierential t"ermal e#ansion e#ansion o dissimilar dissimilar materials materials (. S"ankar Subramanian 9 nd ) @asic conce#t and in s"ell and tube "eat ec"aner S#eciic "eat is deined as t"e amount o "eat enery needed to raise 1 ram o a substance 1Q+ in tem#erature9 or9 t"e amount o enery needed to raise one #ound o a substance 1QC in tem#erature. ; R m.+#. (T2 T1) K"ere= ; R "eat enery (oules) (@tu)9 m R mass o t"e substance (kilorams) (#ounds)9 +# R s#eciic "eat o t"e substance (/kQ+) (@tu/#ound/QC)9 (T2 T1 ) R is t"e c"ane in tem#erature (Q+) (QC) T"e "i"er t"e s#eciic "eat9 t"e more enery is reEuired to cause a c"ane in tem#erature. Substances :it" "i"er s#eciic "eats reEuire more o "eat enery to lo:er tem#erature t"an do substances :it" a lo: s#eciic "eat. T"e main basic eat 6c"aner eEuation is (urandir &rimo9 &6 9 2'12) = ; R < A Tm T"e lo mean tem#erature dierence Tm is= •
Tm = O( T"9in Tc9out) (T"9out Tc9in)P / lnO( T"9in Tc9out) /(T"9outH Tc9in)P
K"ere= T"9in R Inlet tube side luid tem#erature Tc9out Tc9out R utlet s"ell s "ell side luid tem#erature te m#erature T"9out R utlet tube side luid tem#erature Tc9in R Inlet s"ell side luid tem#erature K"en used as a desin eEuation to calculate t"e reEuired "eat transer surace area9 t"e eEuation can be rearraned to become= A R ;/ (< Tm) K"ere= A R eat transer area (mU) (tU) ; H eat transer rate (k/") (@tuV")J < H 0erall "eat transer coeicient (k/".mU.Q+) (@tu/"r.QC) Tm H 3o mean tem#erature dierence (Q+) (QC)
T"e assum#tions assum#tions are neliible neliible "eat transer transer bet:een bet:een t"e system and its surroundin surroundins9 s9 neliible #otential or kinetic enery c"anes9 constant s#eciic "eats9 and t"at t"e luids are not underoin underoin any #"ase c"ane. T"e basic t"eory in t"is e#eriment e#eriment is ;"R;c9 ;"R;c9 :"ic" t"e amount o "eat transer is eEual to t"e amount o "eat absorb. In t"is case9 t"e "eat transer rate across a "eat ec"aner is usually e#ressed in t"e orm ; R m+ # >T and t"e calculation t"at bein used in t"is e#eriment are= •
eat transer rate or "ot :ater9
•
eat transer rate or cold :ater9
•
eat loss ate R
Qh Qc
R m" + # >T R mc + # >T
Q h−Q c
Qc x 100 Qh
•
6iciency R
•
-irt Cactor9 ; R '.5 (; "W;c) :"ere = ; is "eat ec"aned m is lo:rate + # is "eat ca#acity >T is t"e tem#erature dierence T"ere :ere also calculation o 3o Mean Tem#erature Tem#erature -ierence (3MT-). 3MT-9 >T 3M R O( T"9in Tc9out) (T"9out Tc9in)P / lnO( T"9in Tc9out) /( T"9out H Tc9in)P
0erall "eat transer coeicient9 U 0erall 0erall "eat transer transer coeicie coeicient nt at :"ic" :"ic" eEui0a eEui0alen lentt to U D can be calculated by usin eEuation belo:. In t"is case9 t"e 0alue o total "eat transer area A "as been i0en and eEual to '.'5 m2
U =
Q A × LMTD × FT
K"ere= Q
=
FT
eat rate :it" res#ect to t"e a0erae "ead load =
+orrection actor
eynolds Number +alculation
ρv ( d s− d o )
ℜ=
μ
At :"ic" do
=
Tube outside diameter9 m
ds R S"ell diameter9 m µ
=
As
Biscosity9 Biscosity9 taken at a0erae luid tem#erature in t"e s"ell9 &a.s
=
6c"ane area9 m2
A4,6•
S3T6; S3T6; eat 6c"aner Study
Ciure 2= S3T6; S3T6; eat 6c"aner Study
$4*164*
G*+*4; S,4,<6 $4*164*-:
1. A Euick ins#ection :as #erormed to make sure t"at t"e eEui#ment is in #ro#er :orkin condition.
2. All 0al0es :ere initially closed ece#t B1 and B12. . ot tank :as illed 0ia a :ater su##ly "ose connected to 0al0e B2. nce t"e tank is ull9 t"e 0al0e :as closed. !. T"e cold :ater tank :as illed u# by o#enin 0al0e B2* and t"e 0al0e :as let o#ened or continuous :ater su##ly. 5. A drain "ose :as connected to t"e cold :ater drain #oint. $. Main #o:er :as s:itc"ed on. T"e "eater or t"e "ot :ater tank :as s:itc"ed on and t"e tem#erature controller :as set to 5'o+. . T"e :ater tem#erature in t"e "ot :ater tank :as allo:ed to reac" t"e set #oint. *. T"e eEui#ment :as no: ready to be run.
G*+*4; S,4,<6 $4*164*-:
1. T"e "eater :as s:itc"ed o. T"e "ot :ater tem#erature :as :aited until it dro##ed belo: !'o+. 2. &um# &1 and #um# &2 :ere s:itc"ed o. . T"e main #o:er :as s:itc"ed s :itc"ed o. !. All :ater in t"e #rocess line :as drained o. T"e :ater in t"e "ot and cold :ater tanks :ere retained or net laboratory sessions. 5. All 0al0es :ere closed. C6+,*4<644*+, S*;; = T6* H*, E>+?*4 $4*164*- :
1. ?eneral startHu# #rocedures :as #erormed. 2. T"e 0al0es to counterHcurrent S"ell L Tube eat 6c"aner arranement :as s:itc"ed. . &um#s &1 and &2 :ere s:itc"ed on. !. Bal0es Bal0es B and B1! :ere ad8usted and o#ened to obtain t"e desired lo:rates or "ot :ater and cold :ater streams9 res#ecti0ely. 5. T"e system :as allo:ed to reac" steady state or 1' minutes. $. CT19 CT29 TT19 TT29 TT and TT! :ere recorded. . &ressure dro# measurements or s"ellHside and tube side :ere recorded or #ressure dro# studies. *. Ste#s ! to :ere re#eated or dierent combinations o lo:rate CT1 and CT2.
,. &um#s &1 and &2 :ere s:itc"ed o ater t"e com#letion o e#eriment.
R*-6;, 6#eriment A = +ounterHcurrent S"ell L Tube Tube eat 6c"aner (constant CI 1). CI 1
CI 2
TT 1
TT 2
TT
TT !
TT 5
-&T 1
-&T 2
(3&M) (3&M) ('+) ('+) ('+) ('+) ('+) (mm2) (mm2) 1' 2 !!.1 2.2 !.2 !*. 5'.2 * ! 1' ! ,.5 2.1 !$.1 !*., 5'.2 *! , 1' $ .* 1.! !$.5 !,. 51.2 *$ !! 1' * 5., 1.* !!.$ !.* !,.$ *5 1'* 1' 1' 5. 2.' !*. !,.' 5'.* *5 2'2 Table Table 1 = +ounterHcurrent S"ell L Tube eat 6c"aner :it" constant CI 1
6#eriment @ = +ounterHcurrent S"ell L Tube Tube eat 6c"aner (constant CI 2). CI 1
CI 2
TT 1
TT 2
TT
TT !
TT 5
-&T 1
-&T 2
(3&M) (3&M) ('+) ('+) ('+) ('+) ('+) (mm2) (mm2) 2 1' .5 1., !'.$ !., 51.$ 5 2'5 ! 1' ., 2.' !. !*.$ 5'.! 2'1 $ 1' !.$ 2.' !., !*.5 51., 2 1* * 1' 5.2 2.1 !!. !*. $'.1 5 1,$ 1' 1' $.' 2.2 !5.$ !,.2 5'.* *, 1,* Table Table 2 = +ounterHcurrent S"ell L Tube eat 6c"aner :it" constant CI 2
S;* C;6;,7+ 6#eriment A= +ounterH+urrent Clo: H, @,*4
-ensity=
,**.1* k/m
eat +a#acity=
!15.'' /k.4
T"ermal cond=
'.$!$ K/m.4
Biscosity=
'.'''5!,! &a.s
C;1 @,*4
-ensity=
,,5.$ k/m
eat +a#acity=
!1*.'' /k.4
T"ermal cond=
'.$155 K/m.4
Biscosity=
'.'''*'' &a.s
6D&6IM6NT 1 = 1. +alculation +alculation n n eat Trans Transer er and "eat "eat load (constant (constant CT1) CT1) and and +alculation +alculation o 3o 3o Mean Tem#erature Tem#erature -ierence (3MT-) =
•
eat transer rate or "ot :ater9
Qh
3
R m" + # >T kg
1 m 1000 L
1 min 60 s
eat transer rate or cold :ater9
Qc
R mc + # >T
Qh
L
R 1'.'
min
,**.1* m
3
!15
J kg.C
(!*.H!.2) X+ R 5$. K •
Qc
R 2.'
L min
3
1m 1000 L 1000 L
(!!.1H2.2) X+ R 1$52.' K •
eat loss ate R
Q h− Q c
Q h−Q c
R 5$.H1$52.'
R H*,5.' K ε=
−895.70 Q = × 100 =−54.21 Qmax 1652.07
kg 1 min 60 s ,,5.$ m3 !1*
J kg.C
•
6iciency
R
Qc x 100 Qh
R
1652.07 x 100 756.37
R 21.*2 % •
3MT-9 >T 3M R O( T"9in Tc9out) (T"9out Tc9in)P / lnO( T"9in Tc9out) /(T"9outH Tc9in)P
( 48.3− 44.1 )−( 47.2−32.2 ) ( 48.3 −44.1 ) R ¿ ( 47.2−32.2 ) R *.!*Q+ •
-irt Cactor9 ; R '.5 (; "W;c) R '.5 (5$.W1$5.') R 12'!.22
6D&6IM6NT 2 = 1. +alculation +alculation n eat eat Transer Transer and "eat "eat lost (constant (constant CT2) CT2) and +alculation +alculation o 3o 3o Mean Tem#erature Tem#erature -ierence (3MT-) = •
Qh
eat transer rate or "ot :ater9
R 2.'
L min
3
1m 1000 L 1000 L
R m" + # >T
kg 1 min 60 s ,**.1* m3 !15
J kg.C (!.,H!'.$)
X+ R 1''.,1 K •
eat transer rate or cold :ater9
R 1'.' 1.,) X+
L min
3
1m 1000 L 1000 L
Qc
R mc + # >T
kg 1 min 60 s ,,5.$ m3 !1*
J kg.C (.5H
R 111'.$! K eat loss ate R
•
Q h−Q c
R 1''.,1H111'.$! R H1'$. K ε=
−106.73 Q = × 100 =−9.61 Qmax 1110.64
6iciency
•
R
R
1110.64 x 100 1003.91
Qc x 100 Qh
R 11'.$ %
3MT-9 >T 3M R O( T"9in Tc9out) (T"9out Tc9in)P / lnO( T"9in Tc9out) /( T"9out H Tc9in)P
•
( 33.5 −47.9 )−(31.9 −40.6 ) (33.5 −47.9 ) R ¿ (31.9 −40.6 ) R 11.1Q+ •
-irt Cactor9 ; R '.5 (; "W;c) R '.5 (1''.,1W111'.$!) R 1'5.2*
E%$ERIMENT ! :
+alculation n eat Transer and "eat load (constant CT1) and +alculation o 3o Mean Tem#erature Tem#erature -ierence (3MT-) =
CI 1
CI 2
(3&M)
(3&M)
eat transer rate or "ot
eat transer rate or cold
eat loss ate (K)
6iciency (%)
3MT-9 >T3M
-irt Cactor9 ;
ε (%)
:ater9 Qh
1' 1' 1' 1' 1'
(K)
(K) 5$. 1,25.' 22''.5 22''.5 !*1.2
2 ! $ * 1'
(℃ )
Qc
:ater9
1$52.' 2'5!.$* 2$$5.' 22$.*1 25$*.!5
H*,5.' H12,.* H!$5.1* H$.!* H2'*.!5
21.*2 1'$.2 121.1! 1'.! 5.$
*.!* 11.55 1.!* 12.! 1!.5
12'!.22 1,*,.,, 2!2.,! 22*.5* 152!.*,
H5!.1* H$.' H1.!5 H.$ H*1.2
E%$ERIMENT 2 :
+alculation n eat Transer and "eat lost (constant CT2) and +alculation o 3o Mean Tem#erature Tem#erature -ierence (3MT-)
CI 1
CI 2
(3&M)
(3&M)
2 ! $ * 1'
eat transer rate or "ot :ater9
eat transer rate or cold
Qh
(K)
:ater9
(K) 1''.,1 1!.1 1*,.*' 22''.5 25''.!!
1' 1' 1' 1' 1'
Qc
111'.$! 11*.** 1*'!.* 2151.*$ 2$.$
eat loss ate (K)
6iciency (%)
H1'$. 2*.* ,.'2 !*.!, H1.2
11'.$ ,.*$ ,5.1' ,.*' 1'5.!,
3MT-9 >T3M (
℃¿
11.1 12.' 12.* 12.$! 1.'
S;* C;6;,7+ ,* -*;; +1 ,6* *, ,4+-*4 *77*+,
E%$ERIMENT ! 0.8
At tube side ("ot :aterHcoolin #rocess)= Nu =0.023 × ℜ × Pr 3 3 ´ ´V =10 L × 1 m × 1 min =1.67 × 10−4 m
min
π d A = 4
2
1000 L 1000 L
60 s 2
π ×( 0.02664 ) = 4
= 0.000557 m2
s
0.33
-irt Cactor9 ;
1'5.2* 1.' 1*51.2, 21$.11 25$,.1'
ε (%)
H,.$1 2.1! !.,' 2.2' H5.21
´V 1.67 × 10−4 m =0.299 v= = A
s
0.000557
988.18
ρvd = μ
m
ℜ=
μ C % = Pr = k
kg
× 0.299 3
0.0005494 Pa ∙ s
=14327 ( turu!"nt #!o$ )
J ) ( 0.0005494 Pa 0.0005494 Pa ∙ s ) × ( 4175 kg∙&
' 0.6436 m ∙ & 0.8
Nu =0.023 × ℜ × Pr
Nuk = h= d
m × 0.02664 m s
0.33
=3.564
=0.023 × 14327 0.8 × 3.564 0.33=73.55
' m ∙ & ' =1776.91 2 0.02664 m m ∙ &
73.55 × 0.6436
0.8
Nu =0.023 × ℜ × Pr
At s"ell side (cold :aterH"eatin #rocess)= E%$ERIMENT 2
Cor (2 3&M) 3 3 ´ min 1 −5 m ´V =2 L × 1 m × 1min =3.33× 3.33 × 10
min
1000 L 1000 L
60 s
s
0.085
¿
2
( ¿ ¿ 2−( 0.0334 ) ) ¿ π ׿ π ( d s− d o) =¿ A = 2
2
4
´V 3.33 × 10−5 =0.0069 m v= = A
0.0048
s
0.4
ρv ( d s− d o )
ℜ=
μ
955.67
kg m
=
× 0.0069 3
m × ( 0.085−0.0334 m) s
0.0008007 Pa ∙ s
¿ 425 ( !aminar !aminar #!o$ )
μ C % = Pr = k
J ) Pa∙ s ) × ( 4183 ( 0.0008007 Pa∙ kg∙&
' 0.6155 m ∙ &
0.8
Nu =0.023 × ℜ × Pr
0.4
=5.49
0.8
0.4
=0.023 × 425 × 5.49 =5.76
' Nuk m ∙ & ' = =68.68 2 h= d ( 0.085 m−0.0334 m ) m ∙ & 5.76 × 0.6155
´ V
CT2 (3&M)
v
A ( m
3
m ( s
2
¿
ℜ
Nu
Pr
m ¿ ( s
)
h (
' 2
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3.33 × 1 0.0048
0.0069
425
5.49
5. 5.76
68.68
1'.*'
12'.2$
13.91
1$$.'
( !aminar !aminar #!o$ ) !
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0.0139
856
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!aminar #!o$ ) ( !aminar $
−4
1 × 10
0.0048
0.0208
1281
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0.0278
1712
5.!,
17.55
2',.*
5.!,
20.96
25'.'2
( !aminar !aminar #!o$ ) 1'
'.''!*
1.667 ×
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2137
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S;* C;6;,7+ 4 O9*4;; *, ,4+-*4 *77*+,: (ota!"xcha ota!"xchang" ng" ar"a ar"a ) A = π×tu"od×!"ngth = π × 0.02664 m × 0.5 m=0.05 m
* =
Qhot A + ( !m
=
756.37 ' 2
0.05 m × 8.48 ℃
=1783.89
2
' 2
m ∙ &
CT1 (T) +onstantR1' 3&M CT1
CT2
(3&M)
(3&M)
1' 1' 1' 1' 1'
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D7-6--7+
In t"is t"is e#erimen e#eriment9 t9 students students need to sol0e sol0e t"e t"e ob8ecti0es ob8ecti0es :"ic" are to to e0aluate e0aluate and study t"e "eat balance9 3MT- and o0erall "eat transer coeicient9 to calculate eynoldss number at t"e s"ell and tube "eat ec"aner9 to study t"e :orkin #rinci#le o counter lo: "eat ec"aner and to study t"e eect o luid luid lo: rated on "eat ec"aner #erormance. #eror mance. Students studi studied ed abou aboutt t"e t"e ee eect ct o lui luid d tem#er tem#erat atur uree on coun counte terH rHcu curr rren entt lo: lo: "eat "eat ec" ec"an ane er r #erormance.In counter lo:9 on t"e ot"er "and9 t"e "ot and cold luids enter t"e "eat ec"aner in o##osite ends and lo: in o##osite direction :"ile in #arallel lo: bot" "ot and cold luids enter t"e "eat ec"aner in same direction direc tion and same ends (7unus (7unus A.+enel 2'15). So9 one o t"e reason :"y student need to run t"is e#eriment are :"ic" met"od is more eecti0e. In a coHcurrent lo:9 t"e tem#erature o t"e cold stream outlet9 T"9 out must reater t"an Tc9 Tc9out . T"ereore9 T"ereore9 t"e "eat transer transer is restricted by t"e cold cold streamFs outlet outlet tem#erature9 tem#erature9 :"ile in a counter current lo:9 t"ere is no restriction and Tc9 Tc9 out can eceed T"9out. ence in t"is desin9 t"e "eat transer is restricted by t"e cold streamFs inlet tem#erature9 Tc9in. In order to ac"ie0e reater "eat reco0ery9 many researc"er #reerred to use counter current lo:. In e#eriment 1 9 t"e "eat transer coeicient readin increase and and some are decrease as t"e lo:rates increases. T"is #roblem occurs maybe because t"e tec"niEue o t"e luids lo: is not smoot". In order to im#ro0e t"e result9 students need to do some enc"ancement on t"e luid sid suc" as inned surace. In e#eriment 29 t"e "eat transer coeicient increase as t"e lo:rate increase. T"e 3MT- or bot" e#eriment also increases :"en any o t"e lo:rate increases. increases. T"e eynolds number t"at calculated by t"e students students in e#eriment e#eriment 1 is turbulent lo: and or e#eriment 2 9 all t"e lo: are laminar lo:. In e#eriment 19 students run t"e e#eriment at constant 3&M o "ot :ater :"ic" is 1' 3&M and t"e lo: o cold :ater are 2 3&M9 ! 3&M9 $ 3&M9 * 3&M9 and 1' 3&M. Cor e#eriment 29 t"e cold :ater is constant at 1' 3&M :"ile "it :ater is c"ane to 29!9$9* and 1' 3&M. T"e reason :"y t"e lo: rates are c"ane is to study t"e "eat transer in dierent lo: rates. T"e result t"at students et is "eat transer o "ot :ater and also cold :ater did not constantly increase or decrease as lo: rates o cold :ater increase :"ic" are It is also same to e#eriment 2 :"ic" is t"e "eat transer o "ot :ater and cold :ater did not constantly increase or decrease as lo: rates o "ot :ater is increases. Some o t"e e#eriments result t"at "ad done by ot"er researc"er 9 it s"o:s t"at "eat transer "ot :ater and cold :ater or bot" e#eriment increase as t"e lo: rates increase. Students assume t"at maybe t"e "eat loss to surroundin aect t"e result. To a0oid t"is error9 t"e s"ell and tube "eat ec"aner must :ell insulate.
3astly9 t"e :orkin #rinci#le o counter current lo: in s"ell and tube "eat ec"aner is t"e "ot and cold luids enters t"e "eat ec"aner ec"aner rom o##osite o##osite sides and t"e outlet tem#erature tem#erature o t"e cold luid in t"is case may eceed t"e outlet tem#erature o t"e "ot luid. In t"e limitin case9 t"e cold luid :ill be "eated to t"e inlet tem#erature o t"e "ot luid. o:e0er9 t"e outlet tem#erature o t"e cold luid can ne0er eceed t"e inlet tem#erature o t"e "ot luid9 since t"is :ould be t"e 0iolation o t"e second la: o t"ermodynamics9 (7unus (7unus A. +enel9 2'15).
C+;6-7+ As t"e conclusion9 all t"e ob8ecti0e are sol0e by t"e student :"ic" are9 students need to sol0e study t"e "eat balance :ere e0aluated9 3MT- and o0erall "eat transer coeicient :ere determined9 t"e eynoldss number at t"e s"ell and tube "eat ec"aner :ere calculated9 :orkin #rinci#le o counter lo: "eat ec"aner t"e eect o luid lo: rated on "eat ec"an ec"aner er #eror #erorman mance ce :ere :ere determ determine ined. d. T"e T"e results results t"at t"at studen students ts et are not #erect #erectly ly correct due some errors t"at occur :"ile runnin t"is e#eriment.
R**+1,7+!. Make sure t"ere are no air bubbles at t"e tube because :"en #resent o air bubble at t"e tube it :ill aect t"e readin and also :ill "a0e error in t"e calculation. 2. It is recommended to insulate t"e "eat s"ell and tube ec"aner. T"is is because t"e "eats :ill not loss to t"e surroundin. &resently9 t"e s"ell and tube in t"e laboratory did not co0er by insulator9 so t"e result t"at obtained by t"e students "a0e some error due to "eat loss to surroundin. 3. T"e readins o CT19 CT29 -&T19 and -&T2 must be taken :"en t"e system is stabilied and reac" its steady state. T"is is because t"e lo: o :ater must run com#letely in order to et t"e accurate readin. ". T"e im#ro0ement t"at can be made is t"e s"ell and tube "eat ec"aner s"ould t"e eact time :"en to take t"e readin. T"e students or enineer t"at run t"e e#eriment s"ould be take t"e readin at t"e correct timin so t"at t"e readin "at obtained is correct and "a0e less error. 5. T"e :ater :ater to t"e tube tube side s"ould s"ould be be t"e irst and and last lo: lo: rate to be be turned on. on. Ater Ater t"e :ater start to lo: t"rou" t"rou" t"e tube side 9 t"en turn on t"e steam and t"e :ater s"ould be turned on only ater t"e steam "as been turned on so t"at t"e tube and s"ell "eat ec"aner can o#erates eecti0ely.
R**4*+*urandir &rimo9 &6.(2'12)9Shell &6.(2'12)9 Shell and Tube. Tube . etrie0ed Marc" 2,9 2'1$9rom "tt#=//:::.#d"center. "tt#=//:::. #d"center.com/courses/m1/m1content.#d com/courses/m1/m1content.#d
. S"ankar Subramanian.(nd)9Shell Subramanian.(nd)9 Shell and Tube Projects.etrie0ed Projects .etrie0ed Marc" 2,9 2'1$9rom "tt#=//:eb2.clarkson.edu/#ro8ects/subramanian/c"'2/notes/s"elltube.#d T"omasNet.(1*,*).Thermodynamic T"omasNet.(1*,*).Thermodynamic .etrie0ed .etrie0ed Marc" 2,9 2'1$9rom "tt#=//:eb.mit.edu/1$.uniied/:::/CA33/t"ermody "tt#=//:eb.mit.edu/1$.uniied/:::/C A33/t"ermodynamics/notes/node11."tml namics/notes/node11."tml 7unus A. +enel9 A. . (2'15). Heat and Mass Transfer; Transfer; Fundamentals Fundamentals and Alication! Ne: Alication! Ne: 7ork= 7ork= Mc?ra:Hill 6ducation.
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