Tuyen tap Cdng trinh Hdi nghi Khoa hge Cff hge Thiiy Todn qudc, Phan Thiit, 2008 447 Phuo'ng phap dong hoc nghien cuu bom nhien lieu pittong dong CO tua bin Nguyen Minh Xuan*", Hoang Xuan Hoa*^', Ta Van Nham'^> (I) Hoc viin Ky thudt Qudn sir (2) Hoc viin Phdng khdng - Khdng qudn Tom tdt: Ngdy cdc ddng ca tua bin hdng khdng dugc trang hi cdc logi bam nhien lieu tu dgng dieu chinh Mgt cdc logi bam thudng duac su dung Id bam piton Uu the cua bam nhien lieu hdng khdng Id cd dp sudt cao vd dn dinh luv luang tdt Nghien cim dgng hge bam pittong Id mgt bdi todn thiet thuc cdn dugc Idm ro nhdm tdng them sir hieu biet ve tdi de su dung hieu qua Tuy vay ddy Id mgt vdn de phuc tgp cdn phai dugc ddnh gid ket hgp giira ly thuyet vd thuc nghiem Vdn de dugc van dung tinh todn cho bam IIP-A cua dgng ca cu the vd dua cdc nhdn xet cdn thiit A kinetics method in study of fuel piston pump of airturbin engine Abstract: Today, modern airturbine engine has been installing fuel pumps with mechanics of automatic control One of them is piston pumps Superiority of airengine fuel piston pumps is hight pressure and stable flow very well Study of kinetics is pratical-minded problem that needs clearly to solve in order to increase pump's awarenees of airengine to use In practics this method of calculating taked no dlffculty Recomends were advanced by authors In calculation of paper from symple fuel piston pump IIP-Z of airturbin engine Dat van de Ddi vdi bam nhien lieu piton thi van de quan trgng phai xac djnh dugc luu lugng trung binh va tue thdi cua bom, bao dam sy lam viec binh thudng ciia dgng ca tuabin kbi Mat khac tu gdc khai thac va thiet ke thi hanh trinh va sd lugng cac pittong can d mirc vua phai de bao dam dao dgng luu lugng la nho nhat Noi dung 2.1 Nghien cu-u sff dgng hge cua bfftn Trong nghien cuu khao sat, sa dd dgng hge dugc xay dyng tren co sd kel cau thyc cua bam pittong cd ty dgng dilu chinh ciia he thdng nhien lieu dgng ca tua bin khi, (hinh 1) Viec ty dgng dilu chinh ap suit tren bom thyc hien bang thay ddi gdc nghieng cua dTa tya cac diu pittong (dTa nghieng) lam thay ddi hanh trinh cua cac pittong (theo tin hieu ap suit sau bom); tir dd thay ddi luu lugng va ap suat tren bom, [1] Tren hinh 1: 1-Id xo trugt bg dilu chinh vdng quay; 2-con trugt bg dieu chinh vdng quay; 3-con lie ly tam; 4-ld xo dinh hudng; 5-ld xo; 6-pittdng; 6'-dTa phan dau; 7roto; 8- dTa nghieng; 9-6 bi; 10-dem bit kin; 11 - true truyen dgng gan vdi true dong co; 12 khdp ndi true; 13 - true bg dilu chinh vong quay; 14-tay ga; 15-con trugt 16-pitt6ng trg dgng; 17- tai co djnh; 18 - vd d bi; 19 - chdt chan nhien lieu tdi cac vdi phun va cho phep 448 Phuong phdp ddng lire hoc nghien ciru bam nhiin lieu pittong ddng ca buahin dilu chinh bing tay trudng hgp khin cap; 20-cua vag nhien lieu thap ap ; 21- cira nhien lieu cag ap Hinh 1: Bom nhien lieu pittong cd tu ddng dieu chinh Tir sa ket cau cd the bieu dien so dong bgc de nghien ciru (hinh 2): Hinh 2: Sa dd ddng hoc bam piton hi thdng nhiin lieu ddng ea tuabin Tren hinh 2: PQRS la khdi bgm pit tong; A|B, - true dTa nghieng, nai cac pittdng ty mgt dau vao qua trinh djch chuyin dgc theo dng Jdt tren than bam PQRS; AA, va Nsiryin Minh Xudn Hodng Xudn Hoa, Ta Vdn Nhdm 449 BB, la true cac pittdng (ddi xung qua true bam 0 | ) Cac dai lugng khac cd bang Bdng 1: Cdc ky hieu sir dung tinh todn stt Tham sd Ky hieu dan vi Y Dg-rad Gdc nghieng ciia dTa nghieng Gdc nghieng ciia khdi rd to so vdi true bom M> Dg-rad Gdc lech cua khdi ro to P Dg-rad Tdc vong quay ciia rd to bom cao ap n^ Vdng/ph Van toe gdc 0) Rad/ph Tdc vdng quay ciia bam Hb Vdng/ph Van tdc gdc ciia bam ©b Rad/s So lugng pit tdng cua bom cao ap z - Dien tich mat cat ngang ciia ciia pit tdng Fpt cm" 10 Hanh trinh ciia pit tdng cm 11 D.kinh quy dao quay pit tdng ciia dTa nghieng D cm 12 Dudng kinh thiet dien ngang ciia pittdng d cm 13 Luang tang dudng kinh quy dao quay pit tong dTa nghieng D, cm 14 Lugng giam dudng kinh quy dao quay pittdng dTa nghieng Dg cm 15 Lugng bien ddi dudng kinh quy dao AD cm 16 Dudng kinh day khdi rd to Do cm 17 Khoang each tir day khdi rd to den dTa nghieng krd cm 18 Luu lugng cua mgt pit tdng Q cmVph 19 Luu lugng trung binh Q.b cm^/ph 20 Luu lugng tire thdi Qt cmVph 21 Djch chuyen ciia pit tdng gdc lech rdto la (3 Al cm 22 Van tdc chuyen dgng cua pit tdng V cm/ph 23 Hieu suat ciia bam n % 24 Ap suat cira vao ciia bam Pv kg/cm^ Phuang phdp ddng luc hoc nghiin ciru bam nhiin lliu pittong ddng ca buabln 450 25 Ap suat sau bom Pr kg/cm" 26 Cong suat cua bam Nb kgcm/ph 2 Luv luffng trung binh ciia bffm Khi dgng ca lam viec d nhung che khac thi vdng quay ciia bam ciing khac va bam dieu tiet luu lugng ciia bom phii hgp vdi che lam viec cua dgng eg Luu lugng trung binh cua bgm la luu lugng cua pittong tren khoi rdto thoat thdi gian mgt phiit, [3]: Q,b - ^.z.n, luu lugng trung binh mgt pittgng: q=Fpi.T Trd' I vdi : Fp,-dien tich thiet dien ngang cua pit tdng; /-khoang dich chuyen cua pit tong rdto quay mgt vdng ( tir diem ket thiic qua trinh day din diem kit thuc qua trinh hut ); d-dudng kinh thiet dien ngang cua pit long; n la vdng quay rd to cua bom; z la sd lugng pittong day ta nhan thay : dTa nghieng cua bgm nghieng di mgt gdc Gf thi quy dao chuyen dgng cua cac phtong tren bl mat dTa nghieng se la hinh oval Tiic la khoang each D (xem hinh 2) se bien ddi mgt lugng A D Nhu vay dl xac dinh dugc khoang each dich chuyen / ta phai xac dinh lugng biln ddi khoang each A D Xet tam giac vudng AHO ta cd : AH = AO sin( / ) = — sin( / ) Xet tam giac vudng AHA| ta cd : AA| Tir ta suy ra: AA| AH AH cos{A^AH) cos{y + ip) Ds'm{/) 2cos(/-f ^ ) Xettamgiac vudng A|1A ta cd : A|l = A,A sin(v/ ) = Dsm{r)s\n{i^) ^ ^^ 2cos{y-\-i//) (1) Xet tam giac vudng BH.O ta cd : BH, = BO Sin (/) = ^-^'"(^) Xet tam giac vudng BH,B| tacd:BB, BH, cos(r-'i') Xet tam giac vudng BliB, ta cd : Bl, = 6 , sin(^) Tir (1) va (2) ta tinh dugc lugng biln ddi A D: ^ D.s'mjr) 2cos{r-i^) D.s\n{y).sm{y/) 2cos(7-^//) D„ (2) Nguyen Minh Xudn, Hodng Xudn Hoa, Ta Vdn Nhdm 451 A D = D,- D = D - D, = D.Si,Ay).Stn{ip)'''^^-'f'\'''^l^'^\ (3) cos(7 - ^ ) cos(/ -y/) Khi quay mgt vdng pit tdng se thyc hien dugc mot hanh trinh toan phin la doan A.M (ki hieu /)• Xet tam giac vudng MKA, ta cd : A|M = 'i^ ; cos((//) Xet tam giac vudng A|KB| ta cd: A.K = D,, tg (}^) Doddtacd: A.M = H\tg{r) = l cos((//) Tir(3)tarut : D, = D + A D Do dd : / = [D + DSin{r).Stn{y^).r'^'r'^\'''i^'^\)] -l^A 2COS(;K +V^).cos(7-^//) cos(^/^) 2cos(;K + ^^j.cas(x-^^j / = [ 1+ Dat K, = cos((i/) sin-(r).sin-(^) j tg{y) sin"(/)cos'(v/)-sin"(x)sin'(^//) cos((//) sin"(/).sin"(^) sin"(/)cos"(^^)-sin"(/)sin"(^) K = tg{y) Ta cd : / = D ( 1+K,) K cos(^) Luu lugng trung binh cua bam se la luu lugng ciia Z pit tdng rd to quay dugc n vdng thdi gian phut : Qtb = q z n Nhu vay: Q,b = ^"^^ D.(l+Ki) K z n [1/ph] Luu lu'ffng tue thffi cua bffm Luu lugng tue thdi mgt pit tdng cua bom se dugc tinh theo cdng thirc sau, [3]: ,1 ^ d' qi = Fpt • V, = „, , V, Thay v, vao ta co: q= n:.d'.D.tg(r) / ^ £-ii_/ s,n(aj.a; 8.cgs(^^) Luu lugng tdng cgng cua bom tai thdi diem dang xet la: Q = I a, = /=! S - ^ ^ ^ s i n ( a ; + a.i\ ' = cos(^j Phuang phdp ddng luc hoc nghiin ciru bam nhiin liiu pittong ddng ca bitabin 452 Trong dd: ^., 2n La gdc giua hai pit long ke Z la sd pit tong cua khoi rdto Khdi bam pit tdng cua bom HP-A pit long gdc lech giua cac pit tong la 360/7 Nhu vay: = nd^D ^ tg{y)o} ( 360 ^ I ^^ / sin a + / '=icos(^//) day : Q la luu lugng tue thdi; d la dudng kinh thiet dien ngang cua pit tdng; D la dudng kinh quy dao quay cua pit long tren be mat dTa nghieng; vvt, la toe gdc cua bam pit tdng; Dao dgng luu luanu truns binh cua bam la (bien dao ddng) ^^^^—^^ dong luu luong bom la : ^rnax ~ Qm,n ioof%l Qi„ Cudng dd dao Ket qua tinh toan Cac sd lieu su dung tinh toan Tinh toan ddi vdi bom HP-A vdi cac sd lieu sau: Sd pit tdng: Z=7; gdc lech giua true pit tong vdi true rdto cua bam: 4^=15°; gdc nghieng cua dTa nghieng: y =14"'dudng kinh lam viec cua dTa nghieng: = [cm]; dudng kinh thiet dien ngang ciia pit long: d = 1,3 [cm] Ket qua tinh loan luu lugng tue thdi d chl vdng quay Idn nhit vdi 4000[v6ng/phiit] thi hien tren cac hinh 3, 4, n= Ket luan Khao sat dac tinh luu lugng cua cum bgm pit long bam nhien lieu HP-A ta da thu dugc kit qua tinh loan vl hanh trinh, luu lugng cua bom Vdi nhung thdng s6 vl luu lugng ta thiy bam dam bao kha nang cung cap nhien lieu cho dgng eg boat dgng d mgi chl lam viec a mat dat cung nhu tren khdng Qua khao sat ta thiy luu lugng cua bgm la mgt dai lugng kha on dinh Luu lugng dao dgng quanh gia tri luu lugng trung binh Tuy nhien vdi sd lugng pit tdng thi sy dao dgng cua luu lugng nim gidi ban cho phep, [4] C) c ac phuang an khac luu lugng cua bam la mgt dai lugng khong 6n djnh (dl lam ro vin dl chung ta so sanh luu lugng tire thdi sd pit tdng thay ddi, cac thdng sd diu vao vin giCr nguyen) ^ Ket qua cho thay de giam dao dgng cin sir dung s6 pit tdng la le va cang tang nhilu sd pit tdng cang tdt Tuy nhien vdi yeu ciu vl kit ciu ciia bom va luu luang cin dung, su dao dgng cho phep thi bom HP-A su dung pit tdng la hgp ly Nlu tinh loan dao ddng quanh gia tt! trung binh theo % ta thay dao dgng luu lugng cua bam la 2% Nhirng ket qua sg sanh vdi thuylt minh ky thuat dat dd chinh xac va tin cay Cac gia tti hanh trinh luu lugng, ap suat dugc sira chua bam cd sai sd vdi tinh toan tir 45%, [2] Cdng trinh dugc thyc hien vdi sy hd trg cua dl tai nghien ciru ca ban 453 Nguyen Minh Xudn Hodns Xudn Hoa, Ta Vdn Nhdm •.3 ,1 (cm) i1 ^ \\ ^ = 14° \ IJ * Hinh 3: Dd thi hdnh trinh cua pit Idng Q [cmVp] V.\MJ6 lu >rs\ Hinh 4: Dd thi hru hrong trung binh cua bam HTK = niKHiax Hinh 5: Dd thi hru luong tue th&i ciia bam Tai lieu tham khao [1] Nguyin Minh Xuan, Le Van Mot (1992) '"Ly thuyit ddng ca hdng khdng" Hge vi?n Phong khong - Khong quan, Ha Ngi 454 Phuang phdp ddng luc hoc nghien ctru bam nhiin lieu pittong ddng ca buabln [2] Cyc Ky thuat "Quy trinh cdng ngh^ sua chua bam pd tdng hdng khdng" Cue Ky thuat quan chiing Phong khong-Khong quan Ha Ngi 1990 [3] A.A CxcHKHH (1996) '"Teopun APfl." AKaflCMHa HM )KyKOBCKoro, MocKsa [4] r.K) CrenaHOBa B.JI SjiuireHiia (1999) "HpaKcmuiecKue sadamoi om Teopuu AT/f MSM " MAH, MocKBa ... nghien ciru bam nhiin lieu pittong ddng ca buahin dilu chinh bing tay trudng hgp khin cap; 20-cua vag nhien lieu thap ap ; 21- cira nhien lieu cag ap Hinh 1: Bom nhien lieu pittong cd tu ddng dieu... che lam viec cua dgng eg Luu lugng trung binh cua bgm la luu lugng cua pittong tren khoi rdto thoat thdi gian mgt phiit, [3]: Q,b - ^.z.n, luu lugng trung binh mgt pittgng: q=Fpi.T Trd'' I vdi :... phdp ddng luc hoc nghiin ciru bam nhiin lliu pittong ddng ca buabln 450 25 Ap suat sau bom Pr kg/cm" 26 Cong suat cua bam Nb kgcm/ph 2 Luv luffng trung binh ciia bffm Khi dgng ca lam viec d nhung