NGHIEN CLUU - TRAO DPl
UNG DUNG SOFT_SENSOR D £ D I ^ U KHIEN TRUC Ti^P NdNG DO THANH PHAN PROPAN THAP CHU'NG CAT C01
NHA MAY XU" LY KHI DINH C6
APPLICATION OF SOFT SENSORS TO DIRECTLY CONTROL THE COMPOSITION OF PROPANE FOR PETROLEUM DISTILLATION
COLUMN COI - DINH CO GAS PROCESSING PLANT
D i n g Van Chf, Le Ngoc Dung', Lull Hong Quan' 'Truong Dai hpc Mo - Dia cllit 'Tmong Dai hoc Cong nghe Dong Nai
TOM TAT
Thdp chung cdt COI Nhd may Xu ly khi Dinh Co la mot trong nhieng Ihdp chimg cdt dien hinh. Ddc diem ciia thdp Id mot doi luong da bien, giua chung lal Ion lai cdc moi quan he phi tuyen phire tgp. Viec dieu khien, giic on dtnh vd ndng cao chdt luang sdn phdm thdp Id mot de Idi luon CO linh thdi su. Muc lieu cua he thong dieu khien Id duy tri on dinh nong do Ihdnh phdn cdc cdu iir chia khoa sdn phdm dinh vd ddy thdp. Bdi bdo trinh bdy nghien ciru, img dung sofl_sensor trong do ludng true tuyen de img dung vdo vong dieu khien true liep nong do propan ddy Ihdp chung cdl COI. Ket qud nghien dm dgt duac se md ra mot gidi phdp de ung dung he thong dieu khien ndy vdo thuc te sdn xudt. Gop phdn duy tri on dinh. ndng cao chdt luang sdn phdm cua thdp chung cdl trong cdc nhd mdy loc ddu vd xu ly khi hien nay.
Tir khoa: Cdm bien mem. dieu khien nong do, thdp chung cdl, thdp COI Dinh Co.
ABSTRACT
Distillation column COI of Dinh Co Gas Processing Plant is one of the typical chemical processes. Features of Ihe column is a multivariable objects, among them the existence of a nonlinear relationship complexity. Control and improve the product quality of Ihe column is an urgent topic The objective of Ihe control system is to maintain stability composition of the top and bottom. This paper presents the application of soft sensors to control components of propane at Ihe bottom.
Research results can be applied to Ihe control system into practice. Contribute to maintain stability, improving product quality distillation column in oil refineries and gas processing plants.
Keywords: Soft sensor, control component, distillation column, COI column Dinh Co.
NGHIEN C U T U - T R A O D O I
l.DAT VAN BE
Thap chung cdt COI cua Nha may Xix ly khi Dinh Cd, cd nhidm vu tach cac hydrocacbon nhe nhu^ metan, etan ra khoi ddng condensate la mpt hdn hgp long hai ddu vao. Ddng khi nhe thuang phdm trdn dinh thap gdm cac thanh phdn chinh C| vd C^ dugc cung cap cho cac nha may didn. Ddng long dudi day thap chu ydu la cac thanh phdn C3, C^ va C^+ cung cdp cho cac thap chung cat phia sau. Thuc te, de didu khidn ndng dp san pham thap thi ngudi ta se chpn ra hai cdu tu quan trpng nhdt trong tdng sd cac cdu tu he chung cdt dd dieu chinh, dd la hai cau tu chia khda. Cdu tu nhe la dai didn chinh cho cac chit d dinh va cau tu nang la dai dien chinh cho cac chdt d day. Tren ca sd do nong dp thanh phan Propan (C3) dugc chpn la cau tu chinh d day dd dieu khidn. Chung cd ndng dp mol^49.2% [3], ldn nhat d day vd ddng thdi cd mat rdt it tren dinh.
Dd kidm soat ndng dp thanh phdn san pham thdp chung cat, ngudi ta thudng duy tri on dinh ap sudt, ddng thai giam sat va didu khien nhidt dp cac dia tren dinh va day thap. Tuy nhien, chidn lupc didu khidn nhidt dp khdng phai liic nao cung dat hidu qud, dac bidt la d trong cac thap chung cdt da cdu tir. Khi dd vide giii dn dinh nhidt dp khdng the dam bao chae chan la duy tri dn djnh chdt lupng san phdm trong trudng hgp cd nhidu trdn ddng cdp lieu. Ddi phd vdi vdn dd trdn, mot each tidp can khdc dugc de xudt la do ludng cac bidn thu cdp cua qua trinh.
Mpt gidi phap thay thd tin cay, khdng ton kem va khdc phuc dugc cac nhugc didm tren. Ddy chinh la bp cdm bien mdm soft sensor su dung mang noron nhan tao da dugc tac gia xdy dung [1],[2].
Su thanh cdng trong hudn luydn mang na ron nhan tao da lam tien dd dd xay dung he thdng didu khidn true tidp ndng dp thanh phdn propan day thap COI.
Dieu khidn ndng dp thanh phdn chdt dugc thuc ddy bdi khd khan trong qua trinh do
ludmg bdng each sir dung nhung thiet hi phan tich on-line, cung nhu vide thuc hidn dieu khidn khdng dang tin cdy bdi chidn lugc didu khidn nhiet dp. Didu khidn ndng dp thdnh phan thdng qua mdt md hinh du bao softsensor su dung cac phep do thu cdp tu cac cam bien Cling. Hoat ddng do nhanh nay, md ra mpt ca hpi didu khidn san pham mdt each chat che va bd didu khidn se boat dpng hidu qua, loai tru dugc su bidn doi vd ndng dp bdi cac nguyen nhan do nhieu cua qua trinh.
2. D 6 I TU'ONG NGHIEN CUtJ
Md hinh hda thdp chung cat CO 1 dd dugc tac gia nghien cuu md phdng [2], d do cdu tii chia khda nhe (light-key component) etan C^H^
dugc thu hdi tu ddng chung cat da cdu tu trdn dinh thap. Trong khi dd cac cau ttr chia khda nang (heavy-key component) nhu propan C^H^, butan C^Hijj va condensate C^+ dugc tap tnmg dudi day thap chung cdt va tidp tuc dugc tach d cac cpt thap tidp theo. Propan C3H. la sdn pham chinh cua day thap chung cdt, ddi tugng didu khidn tap trung vao vide dieu chinh ndng dp thanh phdn C^ nay de dap ung cac chi tieu dac tinh ky thudt cho thdp chung cat phia sau.
Muc tidu nay khdng dd cd thd dat dugc khi cd sir hidn dien cua cac nhidu khac nhau trong ddng cap lidu. Vi vdy, ydu cdu bp didu khidn can phai chinh xdc, bdn vimg dd cd thd duy tri dn dinh va ddng thdi nang cao chdt lupng san phdm.
3. THIET KE HE THONG DIEU KHIEN Didu khidn mdt qua trinh thanh cong ddi bdi phai cd mpt thiet kd he thdng didu khidn phii hop. Cac yeu td ca ban trong viec thidt kd he thdng didu khien bao gdm: Muc tidu didu khidn, qua trinh do ludng, bidn didu khidn, cdu hinh didu khien va chd dp didu khidn. Xdy dimg he thong didu khien cho chidn lugc didu khidn true tidp ndng dp dugc de xuat cdu hinh nhu so dd
hinh 1 [1],[4]. ®
ISSN 0866 - 7056
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NGHIEN CIJIU - TRAO Dpi
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4. XAC DINH DAC TINH QUA DO CUA QUA T R I N H
Muc tieu didu khidn la duy tri dn dinh ndng dp cua cdu tu chia khoa tren dlnh va day thap bang each didu khidn luu lugng cua ddng hdi luu (dmh vd day). Dac tinh thu dugc bang each thay ddi mpt budc dau vao vdi he thdng hd va ghi lai cdc gia tri tuang ung ddu ra theo thdi gian. Xem xet su dnh hudng cua vide tang 10% luu lugng dong hdi luu dd xdy dung ldn dudng cong cua qua trinh. Ham truyen [2], chinh la quan he giua nong dp thanh phan cdu tir can didu khien (propan) va luu lugng ddng hdi luu nhan dugc tu xung kidm tra md hinh dpng hpc khi xet tdi su thay doi ddng hdi luu ngoai day thap. Dac tinh qua dp nhdn dugc nhu hinh 2,
0 i a 2 D 3 n « i g n a o 7 Q i
Hmh 2 Dgc finh qud do propan khi thay doi 10% luu lugrng dong hoi lieu.Tir dac tinh qua dp tren, nhdn dang dugc ham truydn: Gp(s) = -^—e~**'^
NGHIEN cufu-TRAO Ddl
S. TINH TOAN CAC THAM SO CHO BO DiEU KHIEN
Dieu chinh bp diSu khiln dugc xem nhu mpt qua trinh xac dinh cac gia tri thich hpp cho bp dieu khien. Voi bp di6u khiSn PID, co 3 tham s6 cin diSu chinh nhu he s6 khuSch dai K^, hang s6 thoi gian tich phan T va hSng s6 thoi gian vi phan T^. Phuong phap tiep can pho bien nhat trong nganh cong nghiep lpc hoa dSu dS tinh toan cac tham s6 PID, co khau quan tinh bac 2 chu yeu dua theo phuang phap thirc nghiem Cohen-Coon [3],[4]. Cac tham s6 chinh dinh theo Cohen-Coon dupc cho nhu bang 1, [6].
Bdng 1. Cdc tham so PID theo Cohen - Coon
Bd Siea khien
PID
Kp
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6. MO PHONG VA DANH GIA CHAT LU'ONG CUA BO DIEU KHIEN 6.I.So-dddi^uldiidn
So dd khdi didu khidn true tidp ndng dp propan day thap nhu hinh 3, [2].
Hmh 3. H4 thong diiu khien true tiep nong do thdnh phdn ddy ti
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NGHIEN ClJfU - TRAO D 6 |
Sa dd tren, ddu vao cua soft_sensor dugc ldy true tiep tir cdc ddu ra cua cac cam bidn ciing.
Gdm ap sudt, nhidt dp dinh va day thap, luu lugng, dp suat va nhidt dp ddng cdp lieu. Softsensor dugc hudn luydn trdn ca sd mang na ron nhan tao, dugc dung de chan doan true tuyen ndng dp day thdp.
6.2. Ket qua md phong va danh gia chat luung cua hd dieu Idiidn.
+ So do md phdng:
Dupc thidt lap trdn simulink-matlab [5],[2] nhu hinh 4.
^ J
Hmh 4. Sa do cdu tnic mo phdng hi thong diiu khien propan ddy thdp + Kdt qua md phdng vdi bd didu khidn nong dp propan pha long day thap;
[
Hinh 5. Biiu khien Cfl^pha Idng vdi ldc ddng nhiiu 5%J
I
J/
ITmh 6. Bieu khien C/I^pha long vdi ldc ddng nhiiu 10%
NGHIEN cufu-TRAO D 6 |
6 3 . Danh gia ch^t luung cua bp dilu Idiidn
Cac tham sd ciia bd PID dugc tinh toan dua trdn Cohen - Coon. Sau do dugc ldp vao md hmh thap kdt hgp vdi bp cam bidn mdm (soft-sensor) da dugc hudn luydn. thuc hidn md phdng trdn simulinkmatlab va dugc ddnh gid bdng chdt lugng cua he thdng didu khien thdng qua cac chi tidu:
- Thdi gian dap iing (qua trinh qua dp) vdi bd dieu khidn PID: 300s.
- Dp qua didu chinh vdi bo didu khidn PID: 23%.
-Sai ldch tmh: 2,63.10-5
Kidm tra kdt qua md phdng dap iing vdng kin bang each thay ddi tai hoac nhidu dd danh gia ve hieu qua cua bp didu khidn PID. Su thay ddi 5%, 10% tac ddng nhidu trdn ddng cdp lieu vdi cac didm dat khac nhau trong mpt chu ky ngan. Ket qua chiing minh rang cac thdng sd dugc didu chinh bang Cohen - Coon ddu cd chdt lugng tdt vd loai bd dugc nhimg thay ddi vd ndng dp thanh phdn khi cd nhidu tac dpng.
7. KET LUAN
Didu khidn true tidp ndng dp thanh phdn da dugc phat tridn sau khi da huan luydn mdt mang noTon, xdy dung mdt bd cdm bidn mdm soft_sensor trdn co sd tap dii Ueu bao triim ldn toan bd cac dieu kidn van hdnh. Md hmh dugc danh gia vdi bidn ddng nhieu khac nhau, vdi cac didm dat khac nhau. Y tudng didu khien true tidp ndng dp thanh phan dugc dua ra vdi muc dich didu khien, duy tri nong dp thdnh phan ciia thap chung cat. Ket qua dat dugc frong nghidn ciiu mo phdng da dem lai tridn vpng iing dung vao thuc td dd gdp phdn nang cao chdt lugng san phdm va hidu sudt lam vide cho thap chung cdt ddu hidn nay. •
Ngay nhan bai: 12/5/2015 Ngay phan bien: 10/6/2015
Tai lifu tham lihao:
[1]. D5ng Vdn Chi (2010); Ung dung thugt lan tniyen ngugc ciia mang noron nhdn tgo de xdy dimg bg cdm bien mem trong du bdo ndng do sdn phdm & cgt thdp chung cdt ddu mo. Bao cao hpi nghi khoa hpc thii 19, Tmdng Dai hpc M6 - Dia chit.
[2]. DSng van Chi (2012); Nghien cuu cdc gidi phdp de ndng cao chdt lugng sdn phdm vd hiiu suat ldm viic Clia thdp chung cat trong cong nghiep ddu mo. Luan an tien si ky thuat, Trudng Dai hpc Mo - Dia chat.
[31. Samsung Engineering Condensate.,Ltd_Operating-Manual Rev_D_1987. Tai lidu van hanh nha may xu ly khi Dinh Co.
141 K Ramesh, N. Aziz, SR Abd Shukor, Dynamic Rate-Based and Equilibrium Model Approaches for Continuous Tray Distillation Column. Joumal of Applied Sciences Research, INSInet Publication, 2007.
151 Lutz, Wendt, 2007. Taschenbuch der Regelungstechnik mit Matlab und Simulink. 7.,ergaenzte Auflage.
Verlag Harri Deutsch.
f61 S Majhi.L Litz, 2004. Relay Based Closed-Loop Turning PID Controllers,"Adaption der PID-Reglerparameter im geschlosscnen Kreis durch Einkopplung eines zweipungktreglers".
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