MC LCA. TNG QUAN PRO II.I. Tng quan v PRO II3II. 7 bc s dng phn mm PRO II31. V s qui trnh sn xut42. nh r nhng thnh phn43. La chn phng n nhit ng54. nh r dng nhp liu65. Cung cp nhng iu kin cho quy trnh66. Chy m phng77. Xem kt qu8III. S mt quy trnh s dng PRO II8IV. Nhp d liu v chn thut ton81. Nhp d liu82. Chn thut ton8V. Kim tra tin cy ca kt qu9VI. Mt s cng c h tr10B. CC THIT B V CNG C C S DNG17I. Flash 17II. Shortcut 20III. Distillation24IV. Slide column34V. Caculator371. Tng quan372. Caculator setup373. Caculator procedure40VI. Optimizer44VII. Case study48C. V D 50I. V d v h thng chng ct kh methane501. t vn 502. Xy dng h thng sn xut51a. Nhp cu t51b. Chn h nhit ng52c. Nhp thng s dng nhp liu533. S dng thp Distillation554. Tin hnh m phng60a. Xut kt qub. Chy kt quII. V d v h thng chng ct benzen toluen1. t vn 672. Xy dng h thng sn xut67

a. Nhp cu t68b. Chn gi nhit ng68c. Nhp thng s dng nhp liu683. Tnh ton thp shortcut68a. Chy m phng69b. Tnh s mm l thuyt694. S dng thp Distillation695. S dng caculator v optimizer706. Tin hnh m phng72a. Tin hnh m phng73b. Xut kt qu74D. TI LIU THAM KHO74

A. TNG QUAN PRO II.I. Gii Thiu Phn Mm Pro/II PROII l phn mm ca cng ty SIMSCI, dn u trong lnh vc m phng cng ngh t nm 1967. Cng ty SIMSCI l thnh vin ca Intelligent Automation Division, thuc cng ty Invensys. (a ch website: http://www.simsci-esscor.com ) hot ng trong lnh vc iu khin t ng, cung cp cc phn mm ng dng trong cng ngh lc ho du, thc phm, nng lng,Phn mm PRO/II l phn mm m phng tr gip cc k s cng ngh ho hc, du kh, PolimerT vic tch ra du v kh n nhng quy trnh chng ct, PRO/II kt hp nhng ti nguyn d liu ca th vin thnh phn ha hc rng ln v phng php d on thuc tnh nhit ng tin tin nht. PRO/II l cng c tnh ton d dng cc cn bng vt cht v nng lng, nhm m phng quy trnh trng thi n nh; theo di, ti u ha, ci thin nng sutC th vo trang ch PRO/II bit chi tit v phn mm,cch dng v nhiu h tr khc,c th ng k mua bn PRO/II.II. 7 bc s dng phn mm PROII S m phng kt qu ti Desktop c thc hin qua 7 buc:1. V s qui trnh sn xut: La chn hot ng n v thch hp t PRO/II t nhng biu tng thch hp, tr vo nt biu tng, kch chut, v th n v trong phm vi hot ng bng cch kch ln na. Xc nh r nhng dng bng cch chn nt STREAM, kch chut cho u vo v ra mi n v cng ngh. 2. Khai bo cu tKch nt biu tng nhng thnh phn vo mt danh sch tt c cc thnh phn trong qu trnh. Chn t hn 1,700 thnh phn uc xy dng trong c s d liu ca SIMSCI bng cch nh vo tn thnh phn hoc la chn t danh sch uc xc nh trc .

3. La chn phng n nhit ng

Kch nt chn nhng phng thc nhit ng t danh sch nhng phng thc thng s dng, khi qut ha, phng trnh trng thi, phng thc cht lng hot ng, v nhng gi d liu c bit.4. nh r nhng dng nhp liu

5. Cung cp cc iu kin cho quy trnh

6. Chy m phng

Mt ln bn cung cp tt c d liu uc yu cu v khng cn nhn thy nhng vng , vy l bn sn sng chy s m phng 7. Xem kt quBn nhp chut phi vo thit b mun theo di, chn View Results. V theo di kt qu.Hoc c th chn xut ra file excel d theo di

III. S mt quy trnh dng phn mm PRO/II IV. Nhp d liu v chn thut ton

1. Nhp d liu :Khi nhp d liu cn ch n tnh hp l cc thng s cng ngh thc t, do thit b c th b h hng v cho kt qu sai m khng bit.Chng trnh mun hi t cc thng s phi tng ng v hi ho vi nhau. Mt thng s khng hp l lm qu trnh tnh ton khng hi t lm khng bit nguyn nhn.Qu trnh nhp d liu ch cn nhp mt phn cc gi tr cn thit, cc thng s cn li c tnh ton khi chy chng trnh. Thng s c chia ra lm 3 loi: Thng s khng i: l thng s gi c nh trong sut qu trnh tnh ton nh p sut, nhit , lu lng dng trch ngang Thng s c lng : l thng s phi khai bo hoc khng cn khai bo tu . i vi thng s ny, b tnh ton xem nh l gi tr u ca thut ton lp, kt qu tnh ton c th khc so vi gi tr c lng ban u. Tuy nhin kt qu c lng phi gn k vi gi tr kt qu th chng trnh mi hi t. Thng s khng cung cp: l thng s khng cn nhp, c phn mm qui nh.Khi nhp xong d liu vo, thng s chuyn sang mu xanh. Nu d kin vn cn thiu th c mu v cn b sung cho khi no chuyn sang mu xanh th mi c chy chng trnh.2. Chn thut ton: Trong qu trnh lp, PRO II cn cc gi tr ban u ca thng s, t PR II t ng c lng bng cng c IEG da trn cc thng s cung cp. IEG ch c s dng hai thut ton lp I/O v Chemdist trong PRO/II. Khi m phng qu trnh chng ct du m th I/O thng c s dng v gii nhanh v ph hp cho cc h Hydrocacbon.

Phng php tnh lp I/O (inside/outside): chia cng vic tnh ton thnh hai vng lp, vng lp ni v vng lp ngoi.Vng lp ni PRO/II gii cc phng trnh ca ct chng ct: phng trnh cn bng vt cht, cn bng nhit v iu kin bin. Vng lp ni dng phng php tnh gn ng nn xc nh cc bin s rt nhanh.

Sau khi vng lp ni hi t (sai s gia hai ln lp t yu cu) th PRO/II chuyn sang tnh vng lp ngoi. Ti vng lp ngoi, s tnh cc gi tri nh K ( bay hi tng i ), H (enthalpy) da trn kt qu vng lp ni v thnh phn, nhit . Vic tnh ton cc phng trnh nhit ng c th chim ti 80% thi gian tnh ton v y l cc phng trnh phc tp v thnh phn v p sut.PRO/II chia lm hai vng lp ni v ngoi gim s ln gii cc phng trnh nhit ng, trong c vng lp ni tnh ton gn ng. Lu tnh ton ca phng php I/OKhi chng trnh khng hi t, c nhiu nguyn nhn dn n khng hi t: Thng s u vo khng chnh xc, d kin b thiu hoc qu chc ch nn khng thc hin c.Do m hnh khng hp l nh khng s mm l thuyt, thut ton chn sai, b tnh ton tnh cht khng ph hpDo thng s mc nh cho phn mm khng thch hp: mc d qu trnh hi t nhng khng s vng lp nn khng c p s, do vy cn phi tng thm s vng lp ti a cho php hoc gim h s dampingSai s khc khe, kh t c .V. KIM TRA TIN CY CA KT QU

Khi phn tch kt qu v thy m hnh tnh ton ph hp qui trnh thc t th kim tra tin cy ca kt qu tnh ton bng cch :

1. Thay i b tnh ton tnh cht (phi ph hp vi h ang m phng).2. Thay i cu t gi ca dng nhp liu 3. Khi tng s cu t gi m kt qu tnh ton chnh lch khng ng k th phi ly kt qu mi chnh xc hn .Ni chung bc kim tra tin cy khng nht thit phi c thc hin nu khng c mi nghi ng no.VI. MT S CNG C H TR1. CalculatorCalculator l mt module rt linh hot, nhiu tin ch v c s dng thng xuyn trong qu trnh m phng quy trnh cng ngh.Cc thng s cho qu trnh tnh ton c ly t quy trnh v vic tnh ton s dng ngn ng FORTRAN.Tnh nng c bn ca Calculator: Tnh ton tnh cht ca cc dng c bit. M phng mt s thit b nh bnh phn ng. Xc nh iu kin vn hnh. Kt qu tnh ton t s liu ca quy trnh cng ngh. Tnh ton chi ph hoc li nhun kinh t. Phc v cho cng c Controller v l hm mc tiu ca cng c Flowsheet optimizers.Tin ch ca Calculator ph thuc nhiu vo ngi s dngCalculator gm 2 phn chnh : Setup v Procedure. Setup: truy xut thng s ca thit b v dng c t s quy trnh; gn cc hng s; thit lp cc chui cho dng ra v dng vo; xc nh kch thc ca cc mng ch lm vic v c th m rng nu mun. Procedure: th hin cc php tnh c vit theo ngn ng FORTRAN, cho php thc hin cc chc nng tnh ton, m rng hay tnh lp. Mt s hm c th truy xut thnh phn v tnh cht ca dng t s quy trnh. Cc chng trnh con c bit gip ta tnh ra kt qu trc tip t dng lu cht. Kt qu t Calculator c s dng cho vic vn hnh cc thit b khc trong quy trnh.Cch s dng Calculator: Nhn vo Edit/View Declarations trong ca s Calculator m View Area.

Nhn Parameters nhp cc thng s t s quy trnh cho Calculator. Nhng thng s ny s c truy cp vo Calculator procedure nh l cc phn t ca ma trn P.

Nhn vo Constants nhp cc hng s s dng trong qu trnh tnh ton. Nhng hng s ny s c truy cp vo Calculator procedure nh l cc phn t ca ma trn C. Tuy cc hng s c th nhp trc tip trong qu trnh vit code phn Procedure, nhng ma trn C gip ta tp hp tt c nhng hng s c th thay i khi cn.

Nhn vo Results nhp tn cho cc kt qu tnh ton. Nhng gi tr ny s c truy cp vo Calculator procedure nh l cc phn t ca ma trn R v c dng trong bo co kt qu u ra.

Hnh 21 Nhn vo Arrays khai bo ln cho cc ma trn s dng trong Calculator, bao gm ma trn P, C, R khai bo trc v ma trn IS c dng trong vic s dng gi cc bin ca dng lu cht.

Nhn vo Stream Sequence thit lp trt t cho cc dng. Bng ny c 2 chc nng chnh: kt ni thng tin dng chy gia cc Procedure v cc dng trong s quy trnh; kim sot vng lp trong qu trnh thc hin th tc.

Khi hon thnh vic khai bo trong Setup, click Hide Declarations ng ca s View Area. V Calculator Procedure: y l phn bt buc trong vic lp trnh cho Calculator. Cc dng lnh theo ngn ng FORTRAN c nhp trc tip vo Procedure trong ca s chnh ca Calculator.* Mt s im lu :- Mi hng lnh cha ti a 80 k t, ta c th s dng k hiu & t cui hng lnh biu th s ni tip vi hng lnh di tip theo.- Tt c cc dng lnh, tr lnh PROCEDURE, c th c bt u bng mt dy s t 1 n 99999.- Nhng k t pha sau du $ c xem l ch thch thm.* Cc bin s c nh ngha sn:Cc bin ny bao gm kch thc cho cc ma trn. Ta c th dng lnh DIMENSION trong phn Calculator setup t li s phn t ca mi ma trn.* Mt s dng thng dng: AnTrong A l mt trong cc ma trn C, P, V, R hay B v n l mt s nguyn ch ra s phn t n ca ma trn . A(index)Trong A l mt trong cc ma trn C, P, V, R hay B v (index) l mt biu thc c t trong ngoc n. A(n) An2. OptimizerCng c Optimizer c th tin hnh vic cc i hay cc tiu hm mc tiu bng cch thay i mt hay nhiu bin trong s quy trnh cng ngh n khi t c yu cu (hi t). Ta c th chn la nhiu rng buc cho gi tr cc i hay cc tiu. Hm mc tiu c th l tiu chun vn hnh nh thu c lng sn phm l ln nht hay tn tht t nht, hoc tiu chun v kinh t nh li nhun cc i hay chi ph thp nht. c th ti u cc mc tiu v kinh t, ta phi b sung thm cng c Calculator trong s quy trnh tnh li nhun hay tn tht, sau mi s dng cng c Optimizer cc tiu hay cc i kt qu t Calculator (hm mc tiu).Hm mc tiu:Ta tin hnh vic xc nh hm mc tiu l cc tiu hay cc i trong ca s Optimizer. Nhp hm mc tiu bng cch nhp vo ch Parameter c gch di m ca s Parameter. Hm mc tiu c th l mt tham s ca s quy trnh hoc l mt bin thc ton hc lin qua n 2 tham s khc nhau ca s quy trnh.

Bin s: Bin s ca qu trnh c nhp vo bng cch click vo ch Variables. Trong ca s Parameter, xc nh thng s s thay i, tng t nh trong vic xc nh hm mc tiu. i vi bin s cho dng hay thit b, ta phi nhp vo gi tr cc tiu v cc i.Kch thc bc tin v gii hn:Click vo default step sizes trong ca s Optimizer m ca s Variable Step Sizes. y, step sizes (kch thc bc tin) c mc nh l 1.0, (gi tr mc nh c th thay i), ta c th nhp vo kch thc bc tng i hay tuyt i cho mi bc tnh lp.

Specifications c th c nhp thm vo lm bin iu khin.Click vo Specificationstrong ca s Optimizer m ca s Specifications. Check vo Use Specifications c th nhp cc tham s cho mi SPECification. SPECification c th l mt tham s ca quy trnh hoc l mt biu thc ton hc lin quan n 2 tham s khc nhau. K tip, ta nhp cc gi tr v sai s cho qu trnh tnh.

Constraints (rng buc): gii hn cc bin s trong phm vi s dng. Click vo Constraints trong ca s Optimizer m ca s Constraints. Check vo Use Constraints c th nhp cc tham s cho mi CONStraint. Trong ca s Parameter cho php ta xc nh dng hay thit b dng cho rng buc, tng t nh Specifications.

Cc chn la khc:C rt nhiu chn la cho vic thit lp cng c Optimizer c ch ra bng cch click vo Options trong ca s chnh Optimizer.- S vng lp:S vng lp mc nh ca Pro/II l 20 cng vi s bin hin ti. Tuy nhin ta c th thay i s vng lp theo mun bng cch check vo Specified Number v nhp s vng lp.

Scaling of Optimization Variables:Theo mc nh, cng c Optimizer tnh theo phng php hi t. Cc mc c th c thay i bng cch check vo Use Scaling trong ca s Options b chn. Khi gi tr mc nh cho kch thc bc tin trong ca s Variable Step Sizes s tng t 2% ln 5%.- Sai s chung cho cc bin s (Overall Error in any Variable): Gi tr sai s ngm nh cho cc bin l 10-7. Ta c th thay i nu mun bng cch nhp vo tng ng.- Thay i tng i nh nht (Minimum Relative Change in Objective Function)Gi tr mc nh l 0.005. Ta c th thay i bng cch nhp vo tng ng trong ca s Options.* Advanced Options:Click vo Advanced Options thm vo cc chn la cho cng c Optimizer, nhng iu ny khng cn thit i vi nhng ngi cha c kinh nghim s dng Pro/II.Cn mt s la chn khc nng cao hiu qu cho cng c Optimizes, ta c th tham kho thm trong Users Guide.

B. CHI TIT CC THIT BI. FLASH1. Gii thiu tng quanThit bi phn tach cn bng pha m phong cac hoat ng da trn s cn bng pha. Co th dung m phong 1 s thit bi cn bng n gian nh thit bi bc hi thit bi lng gan,thit bi c c.2. Phng php tinh toan:Pro/II cha nhng phn tnh ton cho nhng trng thi cn bng tch chng hn nh flash drums , mixers,valves,splitters. Flash calculations cng thng c dng xc nh trng thi nhit ng ca mi dng vo cho mt s n v vn hnh . i vi Flash calculation cho 1 vi dng, y c s tng cng ca NC v 3 mc ca t do. NC l s ca tt c cc cu t trong dng ny . Nu thnh phn cu to ca dng v t l c trn ln th cng c 2 bc t do cng c trn . V d nhit v p sut ca tch ng nhit .Ni thm , i vi tt c cc n v vn hnh, Pro cng c th biu din 1 Flash calculation trn dng sn phm ti iu kin u ra.S khc bit enthalpy ca dng sn phm v dng vo l net duty ca n v vn hnh.

H thng cc phng trnh:

3. Flash drumn v ca Flash drum c th c vn hnh vi nhng thng s iu kin , ng nhit im sng , im si bt khc nhau im si bt cng c th c xc nh cho pha hydrocacbon hay pha nc . im cao hn im sng cng c th c xc nh cho tng dng. Ni thm, i vi 1 s dng tng qut c bit nh tc cu t hay l c tnh dng c bit chng hn nh sulfur c cha p sut v nhit .

4. Flash setup

Chn cc thng s cho flash drum

II. SHORTCUT1. Gii thiu tng quanShortcut c s dung trong tinh toan s b xac inh s bc cn thit i vi 1 s phn tach cho trc. Vic tinh toan da trn quy trinh c in Fenske-Gilliland-Underwood, c lam thich ng x ly cac b ngng tu 1 phn hay toan phn. Ta nn s dung cac m hinh tinh toan nhanh trong cac giai oan u cua tinh toan flowsheeting hi tu cac dong hoan lu 1 cach d dang hn, bi cac thng s se lun lun c thoa man ngay ca khi vic inh kich thc co vn .Pro/II iu khin phng php tnh ton chng ct shortcut nhm xc nh trng thi lm vic ca thp nh phn tch cu t, s a cc tiu, t s hi lu ti thiu. Thit b Shortcut gi thit rng lung trung bnh ca cht d bay hi c th c xc nh. Quy trnh Fenske uc dng tnh ton hiu sut v s a cc tiu cn thit. T s hi lu ti thiu uc xc nh bi phng php Underwood. Quy trnh Gilliland uc dng tnh s ia l thuyt yu cu, t l dng hi lu thc t. ng thi phng php ny cng xc nh chc nng ca thit b ngung t v un si c th em li t s hi lu thp nht. Cui cng, quy trnh Kirkbride dng xc nh v tr nhp liu ti u.Shortcut l 1 phng php rt c ch cho nhng ai ln u thit k nhng n thc t. Phng php ny c nhc im l khng hot ng i vi mt s h thng. i vi h thng gn nh khng l tng, shortcut s cho kt qu rt xu hoc khng c kt qu. Trong cc trng hp thp c nhiu cht d bay hi khc nhau shortcut cng s cho kt qu rt xu.Cc ch lm vic ca thit b ngng t c th chn sao cho ph hp: Partial: ngng t 1 phn Mixed: ngng t hn hp Bubble Temperature : ngng t nhit si(chn) Subcooled, Fixed Temperature : nhit qu lnh Subcooled, Fixed Temperature Drop : gim nhit qu lnh2. Phng php tinh toan Quy trnh Fenske:Mi quan h gia tc ho hi gia cu t i v cu t j trn mi a trong thp c th hin qua phng trnh sau

vi x:thnh phn mol trong pha lng y:thnh phn mol trong pha hich s i, j tng ng vi cu t i v jch s N l s a phn ng.i vi nhng thp c bay hi gia cc cu t chnh lch rt nh, ta c th nh ngha bay hi trung bnh. s l ga tr trung bnh ca sn phm nh v sn phm y

S a l thuyt ti thiu c tnh theo cng thc

Quy trnh Underwood:Gi tr ca bay hi ca cc cu t trong dng nhp liu quyt nh cu t no nh cu t no nng. Cu t nh l cu t d bay hi v ngc li.Nu ta t j l bay hi tng i trung bnh ca cu t j

vi j l cu t khaj=1 cu t khaj>1 cu t nh hn cu t khaj