Phân tích động lực học tương tác rotor và ổ trục

NGHIEN CUU - TRAO DOI ' P H A N TiCH DONG LlTC HOC TUONG TAG ROTOR VA O TRUC Van Thanh Ngo, Danmei Xie Vien Co Dong luc, Truang Dai hoc Vii Han, Trung Qudc TOM TAT Trong thiit ki, che tgo rotor, mot sd tham sd cd dnh hudmg true tiep den tinh ndng dgng luc hoc cita mdy vd thuang khdng biit mdt cdch chinh xdc Mdt cdc thdng so ca bdn la dnh huang cua citng d true tdi tdc giai hgn vd trgng thdi dao ddng rieng cua rotor Bdi bdo tien hdnh phdn tich dao ddng cita md hinh turbine mdy phdt dien tren ca sa phuang phdp phdn tu hiru hgn Tdc tdi hgn vd dgng dao ddng rieng duac phdn tich dua trin ca sd thay ddi dd cung ciia d true, tit dd cho thdy cmg d true cd dnh hudng quan trgng din trgng thdi dao ddng cua rotor Tir khoa: Do cimg d true; Dao ddng ngang; Tdc tdi han; Trgng thdi dao ddng MO DAU cua true Can tnic cua turbine may phat dien Trong thiet ke may quay, true la mpt dugc bao gom dgng co dien (MOT), mo hinh nhimg phan quan nhat No anh huong true quay turbine may phat dien thiiy luc 300MW true tiep den hieu suat, tuoi tho va dp tin cay cua voi ty le 1: 10 [4] True quay dugc chia may moc Tham chi sau co cSu may dugc hai phan, rotor ap suat cao va ap suat trung binh thiet ke va van hanh, thay doi hoac sua chiia cac HP-IP (high pressure and intermediate pressure), tham so ciia true co anh huong true tidp din tinh rotor ap suat thap LP (low pressure) dupe lien ket nang hieu qua, tinh kinh te va hieu suit dong cua voi bang khop noi cung True may dugc dpng CO [1] Dp Cling ciia true khong nhimg phu lap dat tren true dugc ki hieu la Brg 1, Brg2, thupc vao thiet ke che tao ma phu thupc vao Brg3, Brg4 True may co tong chieu dai 2.77ni phuang phap lap dat cua chi tilt may [2] vai nhieu bac co duang kinh khac duoc mo Bai bao trinh bay trang thai dao dpng ciia ta nhu hinh mo hinh may turbine may phat dien (tai Phong Thi nghiem, Truong Dai hpc Vu Han, Trung Qu6c) bang phuang phap phkn tu huu han (Finite Element Method-FEM) [3] Kk qua tinh toan chi rang, toe dp toi ban trang thai dao dpng rieng Hinh I: Md phdng he thdng true quay, true ciia cua rotor phu thupc vao su thay d6i cac tham s6 rei ^ ^ TAP CHi CO KHi VIET NAM, S6 nam 2014 www.cokhivietnam.vn turbine mdy phdt diin NGHIEN ciru-TRAODOI PHAN TICH MO HINH 2.2 Tham so true Thong thuang, phuang frinh dao dpng cua he true nhieu bac tu dugc vilt duoi dang sau: Mq + (QG + C)q + Kq = F(t) (I) Trong do: M la ma tran kh6i lugng, K la ma tran dp cung, C la ma tran can, G la ma tran Gysroscopic, Cl la toe dp quay ciia true, F(t) la vec ta luc suy rgng, q la vec ta chua cac tga dp suy rgng Hinh 2: Md phdng d true 2.1 Dao dong tu Dao dgng tu la la dac trung dpng luc hgc CO ban ciia he thong rotor va true Doi voi dao dgng tu (F(t)=0), phuang trinh dugc viet khong gian trang thai nhu sau: C + QG M M dM^ dt\qi K 0" -M (2) He phuong trinh vi phan bac nhat viet khong gian trang thai ^ = {(7^} nhu sau: Thong thuong, true dugc mo phong bang ma tran dp cung va ma tran nhatnhu hinh Hau het cac dang true, moi quan he giiia tai trpng va dich chuyen la moi quan he phi tuyen tinh va phan tich phiic tap hon rat nhieu he tuyen tinh Tuy nhien, de don gian phan tich true, phan tich tuyen tinh van dugc sii dung rgng rai Vi vay, quan he giiia luc tac dung len ngong true la phu thupc vao va toe va dich chuyen ciia ngong true ttong true va dugc uac lugng theo phuang trinh sau[l,2] AX + BX^0(3) (6) Thong thuang, nghiem cua he dugc viet duoi dang: Trong do: f^f la cac luc dgng theo phuong X va phuong y, x,y,x,y la cac tham so dp dich chuyen va van toe ciia ngong true theo phuang x Trong do, X^ Id vec ta phirc, s tri rieng (dual va phuong y X{t) = X,e- ("f) dgng so phuc) 2.3 Phan tich nhay cam ciia he true Ham so tinh toan nhay cam dugc cho boi cong thiic sau [4] Trong do: o),,,. Ngay nhan bai: 19/02/2014 Ngay phan bien: 15/3/2014 Tai lieu tham khao: [1] Friswell M I, Penny J E T , Garvey S D, Lees AW, ^'Dynamics of Rotating Machines", Cambridge University Press, New York, (2010) [2] Vance J, Zeidan F, Murphy B, "Machinery vibration and Rotordynamics", John wiley & Songs, INC, Hoboken, (2010) [3] Van Thanh Ngo, Danmei Xie, Hengliang Zhang, Yangheng Xiong, Yi Yang, "Dynamic analysis of a ng shafting vibration based on finite element" Front Mech Eng 2013, 8(3): 244-251 [4] Xie D, Liu Z, Zhang H, Yang Z, Dong C, "Sensitivity analysis of torsional vibration behavior of the shafting of a turbo-generator set to changes of its mechanical parameters" Power Engineering, 25(4): 462-465 ^ 2005 TAP CHI CO KHi VIET NAM, S6 nam 2014 wwvi^.cokhivietnam.vn ... 2: Md phdng d true 2.1 Dao dong tu Dao dgng tu la la dac trung dpng luc hgc CO ban ciia he thong rotor va true Doi voi dao dgng tu (F(t)=0), phuang trinh dugc viet khong gian trang thai nhu sau:... dpng diu tien thutmg ep dp nhay cam Ion hon so vai cac tin s6 khac Trong tinh toan dpng lire hpe rotor, dl thi anh huang cua dp cirng I true dli voi tic tai han va trang thai dao dpng rieng la... Cambridge University Press, New York, (2010) [2] Vance J, Zeidan F, Murphy B, "Machinery vibration and Rotordynamics", John wiley & Songs, INC, Hoboken, (2010) [3] Van Thanh Ngo, Danmei Xie, Hengliang