Glitserinni sovutish uchun turba ichida turba issiqlik almashinish qurilmasini xisoblang
Berilgan;
Unumdorlik G=17.11tonna/soat
Glitserinning harorati;
Yechish
Glitserinning o’rtacha harorati;
t1 o’rt=0.5(67+37)=52 0C
Glitserinning fizik-kimyoviy xassalari.
Zichlik: ρ1=1109.9 kg/m3 (512 bet lVjad)
Qovushqoqlik: µ1=2.4687∙10-3 MPa/sek(516 bet IX jad)
Issiqlik sig’imi: C1=2593.61 J/kg (562 bet Xl jad)
Issiqlik o’tkazuvchanlik: λ1=0.3977 Vt/m∙K (561bet X jad) Suvning o’rtacha harorati;
t2 o’rt=0.5(11+42)=26.50C
Suvning fizik-kimyoviy xossalari.
Zichlik: ρ2=996.03 kg/m3 (512 bet lVjad)
Qovushqoqlik: µ2=0.8694∙10-3 MPa/sek(516 bet lX jad)
Issiqlik sig’imi: C2=4194 J/kg (562 bet Xl jad)
Issiqlik o’tkazuvchanlik: λ2=0.6 Vt/m∙K (561 bet X jad)
Glitserin sarfini SI sistemasiga o’tkazamiz.
G1==4.75 kg/s
Glitserin uchun issiqlik sarfini aniqlaymiz.
Q1= G1∙ C1(t1bosh- t1oxir)= 4.75∙2593.61(67-37)=369589.4 BT
Suvning issiqlik balansi.
G2==2.87kg/sek
Harorat tasirini tuzamiz.
67 37
42 11 =0.96>2
Δtkat=25 Δtkich=26
Δto’rt=0C
Qurilmaning isitish yuzasini taxminiy qiymatini topish.
Fmax=2
Gliserin va suvning hajmiy sarfi
V1===0.00427 m3/c (gliserin)
V2===0.00288 m3/c (suv)
Issiqlik o’tkazish koeffitsienti.
Reynolds soni
𝜔2= m/s
Diametrni turba ichida turba UAA ГОСТ9930-78 dan aparatni tayorlaymiz.
d1=89х4=0.081 d2=57х3.5=0.057
57х3.5 mm parallel ishchi turbalar sonini topamiz.
nl=
nl=2 bo’lsa tezlikni va Reynolds kriteriyasini suvga nisbatan aniqlaymiz.
𝜔2= m/s
Re2=
𝜔2= m/s
Re2=
Gliserin uchun shunday qiymatlarni topamiz
𝜔1= m/s
Re2=
de=D1-d2=0.081-0.057=0.024 m
Nussel kriteriyasini aniqlaymiz
Nu=0.021∙Ee∙Re0.8∙Pr0.43∙(Pr/Prdev)0.25
Prandtli kriterisini aniqlaymiz
Pr=C1∙µ1/λ1=2593.61∙0.0024687/0.3977=16
Nu=0.021∙1∙8848*0.8∙16*0.43∙1*0.25=255.6
Glitserinda devorgacha issiqlik berish koeffitsienti.
⍺1= Vt/m2∙K
Suvning issiqlik berish koeffitsienti. Prandtli kriteriyasi.
Pr=C2∙µ2/λ2=4194∙0.0008694/0.61=5.97
Nu=0.021∙1∙36569*0.8∙5.97*0.43∙1*0.25=394
Suvdan devorgacha issiqlik berish koeffitsienti
⍺2= Vt/m2∙K
Devorning termik qarshligini aniqlash.
E2dev=.2∙10-4
Kl= Vt/m2
Issiqlik oqimini yuza zichligi.
q11= Kl∙Δto’rt=331.3∙25=8282.5 ℃
Δtldev1vaΔtldev2 taxminiy axamiyatini aniqlash
Δtl= q1/⍺ll=8282.5/423.5=19.56 ℃
Δtldev= q1/E1dev=8282.5∙0.00042=3.48 ℃
Δtl2= q1∙ =8282.5/4216.5=1.96 ℃
Tekshirish;
Δto’rt=Δtl+Δtldev+ Δtl2=19.56+3.48 + 1.96 =25 ℃
Bu yerda;
Δtldev1=t1- Δt11=48.5-19.56=28.94 ℃
Δtldev2=t2- Δt21=23.5+1.96=25.46 ℃ Issiqlik berish koeffitsientiga o’zgartirish kiritish ( Pr/Prdev)0.25
Prandtli kriteriyasini aniqlash. Δtldev1=32.7 ℃
Prdev1=Cdev1∙µdev1/λdev1=2220,7∙0.000282/0.165=3.8 ℃
Prandtli kriteriyasini suv uchun aniqlash. Δtldev2=30.35 ℃
Prdev2=Cdev2∙µdev2/λdev2=4399.5∙0.00074/0.616=5.29 ℃
Atseton uchun issiqlik berish koeffitsienti
⍺1=⍺11( Pr1/Prdev1)0.25=423.5(16/3.8)0.25=606.65 Vt/m2∙K
Suv uchun issiqlik berish koeffitsienti
⍺2=⍺21( Pr2/Prdev2)0.25=4216.5(5.97/5.29)0.25=4345.92 Vt/m2∙K
Kl= Vt/m2
q=k∙Δto’rt=331.3∙25=8282.5 ℃
Δtldev1 =t1-=48.5-℃
Δtldev2 =t2-=23.5-.6 ℃
Issiqlik berish yuzasini topamiz.
Fpl =
UAA larni sirt maydonini 1 ta elementar uzunligi 6 m deb
F1=do’rt∙L=3.14∙0.0535∙6=1.01 m2
Elementlar soni xar biri 2 sektordan iborat
N= ta
Umumiy elementlar soni
9∙2=18 ta
Gidravlik Hisob
ΔP= (λ+Σξ)
λ= ==0.0325
ξ1 = 0.5 ξ2=13.2 ξ3=1
Σξ = ξ1+ξ2+ξ3=14.7 L=6 m
ΔP = (0.02+14.7) =10721 Pa
Ksiloleritmasini isitishu chun IAQ ni hisoblang.
Ber;
G=10 t/soat,tbosh=12℃,tox=60℃,d=50x3mm,P=0.2MPa
Yechish;
1.Suv bug’ining kondensatlanishi t0si
Tkon=119.6 ℃ [LVII-549 bet 0.2 MPa da olamiz]
2.Haroratlar tasirini tuzamiz.
119.6 119.6
12 60<2
Δtkat=107.6 Δtkich=59.6
3.Xaroratlar tasirini o’rtacha farqini aniqlaymiz
Δto’rt =0C
Agarda>2 bo’lsa, u holda Δto’rt=
4.Ksilolning o’rtacha harorati
t2 =tkon-Δto’rt=119.6-83.6=36 0C
5.Ksilolning sarfi berilgan G=10t/soat, uni SI da aniqlaymiz
G2 =
6.Ksilolning hajmiy sarfi
V= m3/s
=850 ksilolning 36℃dagi zichligi [512bet IV-jad]
7.Ksilolni isitish uchun issiqlik sarfi
Q=G2∙C(tox-tbosh)=2.8∙1802∙(60-12)=242189 Kj/soat
C-36℃ dagi solishtirma issiqlik sig’imi [562bet XI-rasm]
8.Isituvchi bug’ning sarfi {7% yo’qotilish bor}
G1 ===0.12 kg/s
r=2208∙103suvning solishtirma bug’ hosil bo’lish issiqligi [549bet LVII-jad]
9.Qurilmani isitish yuzasini maksimal taxminiy qiymati
Ftax=2
K=140 BT/(m2∙K) {172bet 4.8jad}
10.Oqimni harakat rejimini aniqlaymiz
𝜔= m/s
Re=
=0.51∙10-3 - 36℃ dagi ksilolning dinamik qovushqoqligi
{516bet IX-jad}
11.Trubilent rejim uchun Nussel kriteriyasini aniqlaymiz
Nu=0.021∙Ee∙Re0.8∙Pr0.43∙(Pr/Prdev)0.25∙1
( Pr/Prdev)0.25=1.05=1 doimiy son Ɛc=1
Pr=C∙µ/λ=1802∙0.00051/0.127=7.24
λ =0.127 BT/(m∙K) Ksilolning issiqlik o’tkazish koeffitsienti
{561bet 10-rasm}
12.Nu=0.021∙161330.8∙7.240.43∙1.05∙1=118
13.Issiqlik uzatish koeffitsientini topamiz
Kl=1=bug’dan devorgacha issiq berish 2=devordan eritmagacha issiq berish
Ɛdev =devorning termik qarshiligi
1=2.02∙Ɛ1 ∙Ɛr ∙Bt∙()1/3∙l1/3=2.02∙0.62∙0.6∙1070∙()1/3∙31/3=13604Bt/(m2∙K)
Ɛ1=0.62 ga teng {162bet 4.7-rasm}
Ɛr=0.6 bug’dagi havo miqdori{164bet 4.9-rasm}
Bt=1070-119.6℃dagi suv bug’ining kondensatsiya tenglamasiga bog’liq kattalik{162bet 4.6-rasm}
n=trubalar soni l=trubalar uzunligi
2===340
14.Devorning termik qarshiligi
Ɛrdev ={131bet XXXI-jad}r1-suv bug’I tomonidan devordan ifloslanishdagi issiqlik o’tkazish 5800 Bt/(m2∙K)
r2-eritma tomonidan devordan ifloslanishdagi issiqlik o’tkazish 5800 Bt/(m2∙K)
δ=0.002m po’latning yemirilishi
=po’latning issiqlik o’tkazish koeffitsienti
Ɛrdev = =2578 Bt/(m2∙K)
15. Kl= =298.5 Bt/(m2∙K)
16.Issiqlik almashinish qurilmasini issiqlik almashinish yuzasini topamiz
F= m2
Standart bo’yicha 1 yo’lli IAQ ni tanlab olamiz
F=10m2
D=385mm
n=62 ta
l=2 m
Toluolni sovutish uchun garizantal IAQ ni hisoblang
Yechish;
Ber;
Toluol G=18 t/soat,tb1=105℃,tox1=30℃,
Suv tb2=15℃,tox2=45℃,
Yechish;
1.Toluolning o’rtacha xarorati
Δt2o’rt=0C
Yuqorida chiqqan qiymat asosida biz toluolni shu haroratdagi xususiyatlarini aks ettiruvchi birliklarni tanlab olamiz. Bu birliklar jadval asosida olinadi.
Zichlik: ρ1=820.5 kg/m3 (512 bet lVjad)
Qovushqoqlik: µ1=0.35∙10-3 MPa/sek(512 bet lVjad)
Issiqlik sig’imi: C1=1780.7 J/kg (562 bet Xl jad)
Issiqlik o’tkazuvchanlik: λ1=0.151Vt/m∙K (561 bet X ja)
2.Suvning o’rtacha xarorati
Δt2o’rt=0C
Yuqorida chiqqan qiymat asosida biz suv shu haroratdagi xususiyatlarini aks ettiruvchi birliklarni tanlab olamiz. Bu birliklar jadval asosida olinadi.
Zichlik: ρ2=995.7 kg/m3 (512 bet lVjad)
Qovushqoqlik: µ2=0.82∙10-3 MPa/sek(512 bet lVjad)
Issiqlik sig’imi: C2=4184 J/kg (562 bet Xl jad)
Issiqlik o’tkazuvchanlik: λ2=0.616 Vt/m∙K (561 bet X ja)
3.Issiqlik yuklamasini aniqlaymiz
Q=G∙C1(tb1-tox1)=5∙1780.7∙(105-30)=667763 BT
G=18 t/soat=5kg/s
4.Suvning sarfini issiqlik balans tenglamasidan aniqlaymiz
G2==5.3 kg/sek
5.Temperaturalar farqi
105 30
45 15 =4>2
Δtkat=60 Δtkich=15
Δto’rt=0C
6.Turbulen rejimdagi oqim uchun 25x2mm o’lchamli trubalar sonini aniqlaymiz
n=G/(0.785∙µ1∙d∙Re)=5(0.785∙0.35∙10-3∙0.021∙15000)=57
7.Quyidagi tasnifni g’ilofsimon IAQ ni tanlaymiz
D=325mm n=61 ta 1 yo’llik {215bet 4.2-jad}
8.Reynolds kriteriyasini aniqlaymiz
Re=
9.Toluol uchun Prankli kriteriyasi
P1===4.13 u holda
⍺1= ∙Re0.8∙Pr0.43=0.151∙142060.8∙4.130.43=583.2 Vt/m2∙K
10.Suv uchun t2o’rt=300C bo’lganda Pr=5.56 ga teng
(564 bet XIII ras)
11.Trubalar orasidagi suvning harakat tezligini aniqlaymiz
Wsuv=G2/[ρ2∙0.785(D2-n∙d2)]=5.3/[995.7∙0.785∙(0.3252-61∙0.0252)]=0.1m/s
12.Reynolds kriteriyasini topish uchun dэni topamiz
dэ=D2-nd2\D+nd=0.3252-61∙0.0252\0.325+61∙0.025=0.0365m
13.Reynolds kriteriyasi
Re2=oraliq
Reynolds kriterisini 10000 deb qabul qilamiz. Nu esa
Nu=1.72∙(dэ∙Re)0.6∙Pr0.33=1.72∙(0.0365∙10000)0.6∙5.560.33=104.4
15.Devorning sovutuvchi suvga issiqlik berish koeffitsienti
⍺2=Nu∙\dэ=104.4∙0.616\0.0365=1762 Vt/m2∙K
16.Issiqlik uzatish koeffitsientini aniqlaymiz
Kl=.8 Vt/m2∙K
17.ƐΔt qiymatini aniqlash uchun P va R katalik topiladi
P=toxsuv-tbsuv/tbtol-tbsuv=45-15/105-15=0.33
R=tbtol-toxtol/toxsuv-tbsuv=105-30/45-15=2.5
Bu qiymatlardan ƐΔt=0.49 bo’ladi (560bet 8-rasm)
18.Uning Δto’rt2=ƐΔt∙Δto’rt1=0.94∙32.5=30.55℃
19.Talab etilgan issiqlik almashuv qurilmasi almashinish yuzasini topamiz.
F=.9 m2
Standart bo’yicha (215bet 4.12-jad) dan
F=65 m2 D=600 mm n=206 ta
l=4 m
Uzluksiz ishlovchi elaksimon tarelkali rektifikatsion kalonnani hisoblang. Aralashma benzol-toluol (50%-50%).Unumdorligi G=10t/soat atmosfera bosimi ostida ishlaydi, distilyatsiyaga benzolning kerakli miqdori XD=96%,kub xolidagi toluolni kerakli miqdori,XK=98%,Par bosimi P=3 kg/m2(0.3MPa)
I.Moddiy xisob
Ditilyatning massaviy sarfini GD(kg/soat) orqali kub qoldiq massaviy sarfini Cw(kg/soat) orqali aniqlaymiz. Ular quyidagi tenglama asosida topiladi.
GD+Gw=10000
GD∙0.96+Cw∙0.02=10000∙0.5
0.02-98% kub qoldiqdan qolgan miqdor
0.5-50%
2. GD=10000-Gw
GD∙0.96+Gw∙0.02=10000∙0.5=(10000- Gw)∙0.96+ Gw∙0.02=5000
9600-0.96Gw+0.02Gw=5000
0.94Gw=4600
Gw=4894(kg/soat)
3.GD=10000- Gw=10000-4894=5106(kg/soat)
4.Keyingi hisoblar uchun distilyat va kub qoldig’ini mol ulushda ifodalaymiz
Xf===0.541
5.Distilyat
Xd===0.966
6.Kub qoldig’i
Xw===0.022
7.Oziqlanishdagi solishtirma mol sarfi
F===1.82
8.Flegmaning minimal soni
Rmin===1.135 Bu yerda Yf=0.74-benzolning bug’dagi mol ulushi,oziqlanishda suyuqlik bilan muvozanati. {327bet 7.7-rasm}
9.Flegma sonini topamiz
R=1.3Rmin+0.3=1.3∙1.135+0.3=1.78
10.Ishchi tizim tenglamasi
a)Kalonnaningyuqoriqismida;
Y===0.640x+0.347
b)Kalonnaning quyi qismida;
Y===1.3x-0.006
Kalonna diametrik va bug’ tezligini topish
11.Suyuqlikning o’rtacha konsentratsiyasi
a)Kalonna yuqori qismida
XIcp=(XF+XD)/2=(0.541+0.966)/2=0.753
b)kalonna quyi qismida
XIIcp=(XF+XW)/2=(0.541+0.022)/2=0.281
12.Bug’ning o’rtacha konsentratsiyasi ishchi tizim tenglamasi ⑩dan topamiz.
a)Kalonna yuqori qismida
YIcp=0.640x+0.347=0.64∙0.753+0.347=0.828
b)kalonna quyi qismida
YIIcp=1.3x-0.006=1.3∙0.281-0.006=0.359
13.Bug’ning o’rtacha xaroratini t-x,y (7.6-rasm) diagrammadan topamizYIcp= 0.828 YIcp= 88℃
YIIcp=0.361tIIcp= 103℃
14.Bug’ning o’rtacha mol massasi va zichligi
a)MIcp=0.829∙78+0.171∙92=80.3 kg/k mol
Bu yerda
0.829-------------- YIcp
0.171----1---0.829
ΡIcp=MIcp∙T0/22.4∙tIcp=80.3∙273/22.4∙(273+88)=2.71 kg/m3
b)MIIcp=0.361∙78+0.639∙92=87kg/k mol
ΡIIcp= MIIcp∙T0/22.4∙tIIcp=87∙273/22.4∙(273+103)=2.81 kg/m3
15.Kalonnadagi bug’ning o’rtacha zichligi
Ρo’r.p.=(ΡIcp+ΡIIcp)/2=(2.71+2.82)/2=2.77 kg/m3
16.Suyuq benzol va toluolning zichliklari yaqin. Kalonna yuqori qismida YD0.965 bo’lganda xarorat 82℃,bug’latish kubida esa XW=0.023 bo’lganda 109 ℃ ga teng. Suyuq benzolning 82℃ da gizichligi ρb=813 kg/m3; suyuq toluolning 109 ℃ da gizichligi ρt=783 kg/m3 Kalonnadagi suyuqlik o’rtacha zichligini qabul qilamiz;
ρж=(ρb+ ρt)/2=(813+783)/2=800kg/m3
17.Bug’ning kalonnadagi tezligi. Tarelkalar orasidagi masofa <<Калоние Апарати>> katalog-malumotnoma kitobidan olamiz.
H=300mm elaksimon tarelkalar uchun C=0.032mm grafik 7.2 dan topamiz. {323bet П.Р.}
𝜔=C=0,032=0,54m/s
18.Kalonnadan o’tayotgan hajmiy sarfni toppish uchun
To’rt=(88+103)/2=96 ℃
Xajmiy sarf
V=GD(R+1)22.4TcbPo/MDTO3600P=5106(2.78)∙22.4∙369∙1.033/78.5∙273∙3600∙1=1.57 m3/s
MD=XD∙Mb+(1-XD)∙Mt=0.966∙78+0.034∙92=78.478
P0=1.033 atm bosimidagi absalyut bosim.
Tcb=273+96=369 ℃
P=1 partsial bosim
19.Kalonna diametric
D===1.92 m
20.<<Калоние Апарати>> kitobidan D=1900mm ni olamiz unda kalonadagi parning tezligi
W=V/0.785∙D2=1.57/0.785∙1.922=0.6 m/c2>
Do'stlaringiz bilan baham: |