PETROVIETNAM AP DUNG PHUONG PHAP TINH TOAN THL/C NGHIEM ZIEGLER & NICHOLS XAC ! N H C A C THAM SO CHO BO DIEU KHIEN LUU LUONG DONG TRONG CONG NGHIEP DAU KHI ThS &6 Manh Tuan TrUdng Cao dang Nghe Dau Email: tuando.pvmtc@gmail.com Bg dieu khien PID vdi tham sd dieu khien (P - proportional -t^le,l- integral - tich phdn, D - derivative - vi phdn) dang dUUc sUdung rgng rdi diduy tri lUu lugng dong va cac thdng so cdng nghe khdc d gid trj cdi dgt tgi cde nhd mdy hda ddu cua Petrovietnam Tuy nhien, di' bg dieu khien Idm viec hieu qud cdn phdi xdc dinh cde tham sddieu khien P, I, D phu hap Phuong phdp tinh todn thuc nghiem cde tham sddieu khien P, I, D cua Ziegler & Nichols cho bg dieu khien PID dUn I gidn, nhanh chdng, hiiu qud vd khd chinh xdc Do cac thdng sdcdng nghe quan trgng cua nhd mdy dugc kiem sodt on dinh theo thiet ketgo sdn pham cd chdt lucfng cao Kjf TUkhda: Tham so dieu khien, bo dieu khien dong, luu luang dong, PID, cong nghiep dau khi, Ziegler & Nichols Mo hinh Lflu Iflpng dong la mdt bien qud trinh eo bdn dnh hfldng Idn tdi eac qud trinh edng nghe, dac biet vdi nganh cdng nghiep dau ma hau hdt cac nguyen lieu dau vao ^ va san pha'm dau hoae la chat Idng, hoae la chat khi, ji chang han nhu dau thd va xdng/dau tai nha may Ipc hda dau, nha may phan tach khi, nha mdy dam Khdng chi nganh cdng nghiep dau ma cd cac nganh cdng nghiep khde eung vay Thdng qua lUu Iflong ddng, ed the dieu khien duoc ca ve trao ddi khdi Iflpng, trao ddi nhiet va trao ddi nangIflpng fdi Trong cae nha may hda dau, Iflu Iflong ddng dflPc sfl \ dung de dieu khien hau het eae bien qua trinh khac rat hieu qua.Tfldd kiem sodt cde qud trinh eong nghe dn dmh de eho sdn pham chat Iflpng cao Vi du: chinh Iflu lupng ddng vdo vd ddng hop ly se gifl dflpc mfle d i u thd bdn d gia trj mong mudn; hoac chinh ddng dau thd va dong hdi Iflu hop ly se kiem sodt dflOc nhiet dp dinh thdp chflng c a t d l c d sdn p h i m xang chat Iflpng Bd dieu khien PID vdi tham sd dieu khien (P proportional -ty 1$, I - integral - tich phdn va D- derivative - vi phan) dang dflpc sfl dung rat rdng rdi dieu khien dieu tiet cac nhd may che bien hien dai Bp tham sd P, I, D quyet djnh chat Iflpng dieu khien eua bd dieu khien Do dd, can phdi cd phflOng phdp don gidn, hieu qua de xdc djnh cde thdng sd Phuong phdp tinh todn thfle nghiem cae tham sd dieu khien cP bdn cfla Ziegler & Nichols cho bd dieu khien PID da dflpc ap dungthdnhcdng Md hinh trinh bay he thdng dieu khien Iflu IflOng ddng nfldc bang cde thiet bt/he thdng Ifldng - tfl dpng - hda hten trfldng (field instruments), cde thiet bi cdng nghe thfle, gdm cd: PhflOng tien Iflu Iflong ddng FT-1: cd cdm bidn la tam orifice, Iflu Iflpng ddng the ti'ch thfle te, rdi gfli tin hieu tdi bd dieu khien Bd dieu khien FIC011 kieu PID: nam he thdng dieu khien phan tan Centum CS3000 R3/Yokogawa (so sanh tin hieu PVvdiSV,xflly sai lech rdi xuat tin hieu MV [manipulated variable - bien thao tae) tdi bp chuyen doi tin hieu dien sang nen (l/P transducer)) Van dieu khien kieu nen, thfldng ddng: di kem l/P transducer de bidn ddi tin hieu ddng dien - 20mA sang tin hieu nen tieu chuan - Spsig de dieu tiet dp md van dieu khien CV-1 lam thay ddi lflu Iflpng ddng Mdi quan he gifla Iflu Iflpng ddng Q(t) va tdn that dp van dieu khien, ma sat dfldng dng va ma sat tam orifice thfldng la he phi tuyen Trong thu'c te, dflpc coi la tuyen tinh bang cdch phan tieh eac bien pham vi gidi ban quanh diem van hanh, vay mo hinh todn hpc dflpc tao nhfl Hinh Trong do: i|3 HOA - CHE BIEN DAU Khi Xac djnh tham so dieu khi^n PID b^ni phuang phap thUc nghiem cua Ziegler g Nichols Xdc djnh tham sd dieu khien PID bSnj phfldng phap thu'c nghiem cfla Ziegler & Nichols thfle hi^n theo trinh tfl sau: 3.1 Ldy dudng phdn Ung Dau tien thu thap dfldng phdn flng ciJa doi tflPng dieu khien trfldc tdc ddng dieu khien ]J dfldng thi the hien sfl thay ddi cua Iflu lUOng ddngtrfldcthayddidpmdvan , 3.2 Tinh cac tham so cua dong qud trinh Tfl dfldng thj xac djnh dflpc thude tinh K Van (tht/ing ddng), I P}:B D o d d phdi d|t h f l d n g d i e u khidn n g h j c h c h o b p d i e u khien F l C O l l 1^ = 4,1(5) 3,3 L, Tp = 5,6(s) T i n h t o d n cac t h a m sd didu khien P, I, D (Bang 3) 83[Kp\ 4.3 Kiem nghidm Igi cde tham sddieu khien D f l p c t h f l e hten b a n g cdch nap cde b d t h a m sd P, I, D cho t f l n g kieu d i e u k h i e n (kieu P, kidu PI va kidu PIO) cho b d d i e u k h i e n lflu Ifldng FIC011 t h d n g q u a giao diei t u n i n g D e FIC011 d che d p t f l d p n g sau d d dp dung t h a y d d i bfldc dOn vi (tang) vdi ASV = 5% T h e o doi va p h d n tich d f l d n g d o t h j d a p flng cua FICOl t f l ddng d i a c h i n h M V (dp m d van) d e dfla Iflu Iflpng d o n g thfle te l^n SV m d i D i e u khien kieu P ( H i n h ) D i e u khien kieu PI ( H i n h 9) D i e u khien kieu PID ( H i n h 10) Hinh Chon hudng dieu khien nghich cho bo dieu khien database Hinh 10 Dieu khien kieu PID Bdng Ke! qud Imh todn ede tham sddieu khien P Dieu khien kieu P l(s) I 42 \ ' P Oieu k h i l n kieu PI ' ' Ks} " 3,3 Lp no\K,\f lQO\Kp\:f111,7 D(s) 9999,9 oiu KHl-50 2/2016 | p i e u khien kieu p i b D(s) 83\K,\:^ I (s) 2,0 Lp D(s) 0,05 Lp PETROVIETNAM Ket luan md hinh toan hpe thdi gian ngan Cach don gian Trong Hinh - dieu khien kieu P: bd dieu khien khong the dfla dflpc PV (Iflu Iflpng thfle te) ve Iflu Iflpng mong mudn SV mdi Luon co sai lech (offset) Trong Hinh - dieu khien kieu PI: bd dieu khien nhanh chdng dfla dfloc PV ve va on djnh d SV Trong Hinh 10 - dieu khien kieu PID: bd dieu khidn de dieu chinh tham sd tuning cua vdng dieu khien la dp dung phflOng phdp tinh todn thyc nghiem cua Ziegler & Nichols PhflOng phdp se hieu qua ddi vdi cac qua trinh co dac tinh gan gidng vdi tre bac nhat Tai li^u tham khdo Bruce R.Whalen Basic of instrumentation rat nhanh ehdng dfla dflpc PV vd SV, nhflng ket qua lai vot Petroleum extension Service, division of continuing Id tr^n (overshoot) vd vot Id dfldi (undershoot) Education University of Texas at Austin 1983 Do qua trinh ddng dap flng nhanh, thdi gian tre khdng ddng ke, nhieu loan chi rung ddng cfla mdy bom vd ddng xody, tfl ket qud neu tren rut kieu dieu khien thich hop la PI (ty le - tich phdn ket hpp) Hoang Minh Son Gido trinh CO sd he thong dieu khiin qud trinh Nhd xuat bdn Bach khoa Ha Ndt 2009 J.G.Ziegler and N.B.Niehols Optimum settings for automatic controllers.Ttam ASME 1942; 64: p 759 - 768 Qud trinh dieu khien phflc tap vd khd cd the phat trien Application of Ziegler & Nichols' experiment method for calculating the parameters for flow controllers in the petroleum industry Do Manh Tuan Petrovietnam Manpower Traing College Email: tuando.pvmtc@gmail.com Summary PID controllers with control parameters (P - proportional, I - Integral, and D - derivative) are widely used to maintain flow rate and other variables of various processes at set values in Petrovietnam's petrochemical plants In order to ensure the proper function of these controllers, suitable control parameters ofP, I and D need to be found The Ziegler & Nichols' experiment method has been applied for calculating the P, I and D parameters for the PID controllers because it is rather simple, fast, effective and correct The critical process variables at the plants have, therefore, been kept stable at setpoints, resulting in the production of high quality products Key words: Control parameter, flow controller, flow rate, PID, petroleum industry, Ziegler & Nichols fliU KHl sd 2/2016 43 ... BIEN DAU Khi Xac djnh tham so dieu khi^n PID b^ni phuang phap thUc nghiem cua Ziegler g Nichols Xdc djnh tham sd dieu khien PID bSnj phfldng phap thu''c nghiem cfla Ziegler & Nichols thfle hi^n theo... va on djnh d SV Trong Hinh 10 - dieu khien kieu PID: bd dieu khidn de dieu chinh tham sd tuning cua vdng dieu khien la dp dung phflOng phdp tinh todn thyc nghiem cua Ziegler & Nichols PhflOng phdp... ddng thuan K < FIC011 100,0%p OPN 3.4 Tinh todn PID Cac tham sd dieu khien PID dupe ttnh toan bang cdng thfle thfle nghiem cua Ziegler & Nichols (Bang 2) CLS 0,0% Ket qua thUc hi^n tren he thdng