KHOA HOC CONG NGHE
M O T S O K E T Q U A IVBHIEIV CIJLI T U A BIIM HUOIMG CHEO CAIVH CD DflMH P H U C V U T H U Y DIEIM IMHD V I E T IMAIVI
Pham Phiic Yen\ Biii Qudc Thai^
TOM T A T
Bai bao trinh bay ket qua nghien ciru loai tua bin moi, tua bin budng cheo canh co dinh pham \i cong suat nho, cot nuoc thap va trung binh. Loai tua bin nay co ket cau banh cong tac don gian, hieu suat cao, co the thay the tua bin tam true va tua bin huong true canh co dinh trong pham vi tren va phii hgp nang luc che tao tai Viet Nam. Thong so lam viec cita mo hinh tua bin nay la: liru lugng quy din Q'i= 9001050 1/s, van tdc quy din n'i=8595 v6ng/phut, hieu suat tdi da ri„,„= 83%. Viing lam viec: cong suit tir 801000 kW; cot nuoc tir 2040 m.
Tir khoa: Tua bin hudng cheo, nha may thuy dien, cong suit nho.
LDATVANDE ' -
O nude ta hien nay, trong pham vi thity dien nhd va cue nhd, vung cot nude t h i p va tmng binh mdi nghien ciiu, img dyng hai loai tua bin hudng tryc canh cd dinh va tam true. Tua bin hudng cheo canh xoay cd hieu suit cao hon, vung l i m viec tdi uu rdng hon, dac biet hieu qua trong pham vi nay vdi ti tdc n,= 250 450 v/p, tuy nhien ket ciu phirc tap nen thudng dugc ap dung cho c i c tram thity dien ldn.
Viec nghien ciiu ap dung dac tinh nang lugng tdt cua tua bin hudng cheo (TBHC) cho thity dien nhd v i cue nhd cd y nghia thuc te r i t ldn.
Tir lap luan tren, cho thay r i n g Nghien cuu ung dung tua bin hudng cheo canh cd dinh phirc vu thuy dien nho & Viet Nam l i r i t can thiet. Tua bin hudng cheo canh cd dinh se phu hgp vdi thuy dien nhd va cue nhd, vimg cdt nude t h i p va tmng binh. Nd cd ket ciu don giin, sd canh it hon b i n h cdng tic tua bin tam true, dd che tao hon do dd gia thanh re hon, cd the thay thd cho 2 loai tua bin hudng true canh cd dinh vi tam true, phii hpp cdng nghe che tao trong nude.
II. HUONG NGHIEN CUU
Qua nghien cim img dyng TBHC cinh xoay tren the gidi, rut ra cac nhan xet sau: TBHC cd ti tdc n, = 250 - 450 v/p (cot nudc t h i p v i tmng binh) lim viec hieu qua hon tua bin hudng true v i tam true:
\aing lim viec tdi uu rdng hon, hieu suit 77^,^^ cao hon (88 92%). Cic ket q u i nghien ciru cho thiy cac 'Vien Thuy dien \ a Nang luong Tai tao - Vien Khoa hoc Thiiy Igi Viet Niini
- Xru-onc Dai lioc Bach khoa Ha Npi.
thdng sd eua he thdng din ddng (z, 1/t, dt. Do, D,, Dj, 6) rit quan trpng i n h hudng den dac tinh lim viec eua tua bin. Vd ket ciu md hinh: TBHC canh xoay cd ket ciu true dimg, khe hd giiia vinh canh v i budng l i khe hd ndn yeu ciu dp hd rit k b i t khe, sd canh binh cdng tic (BCT) tir 6 12 cinh [5],[6].
Tir cac ket q u i phan tich v i nhan xet tren, ta cd cac ket luan sau: Viec ap dung rap khudn cic nghien cuu cita TBHC canh xoay cho thity dien nhd va cyc nhd a Viet Nam khdng phu hpp vdi k h i nang che tao trong nude, gia thinh che tao r i t cao. Vi vay, xin de xuat hudng nghien cvru va pham vi nghien cuu l i loai banh cdng t i c (BCT): kieu cd dinh, cd vinh ngoii try, sd canh gidi han de giai quyet bii toin thyc tidn, phii hpp ve mat thuy lye ciia he thdng dan ddng.
- BCT cd vinh try ngoii: chuyen dugc khe hd mep cinh vdi budng tir hudng ndn sang hudng true, do dd dd dang hon nhieu cho ehe tao va lip rap.
Tang tinh dn dinh cua BCT cd kich thude nhd, giim tdn thit diu miit canh.
- BCT cd sd la cinh gidi han, cd dinh phu hgp n h i may thuy dien nhd va cyc nhd khdng cd hd dieu tiet nam, cot nudc it thay ddi. Kieu BCT nay lam tang k h i nang thoit, cd the md rdng vung lim viec v i dd che tao bing phuong p h i p due hen.
Pham vi i p dyng TBHC cinh ed dinh cdng suit nhd, eye nhd cdt nude thip v i tmng binh: cdng suit:
50 - 1000 KW, cdt nudc: 20 - 40 m, sd vdng quay dac trung: 250 - 450 vg/phut.
III. PHUONG PHAP NGHIEN CUU
Phuong phap nghien ciiu ke! hgp giiia nghien ciiu ly thuyet va thyc nghiem. Nghien ciiu ly thuyet:
NC i NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1 /2011 27
Tinh toan thief ke cic miu cinh; tinh toin phan bd van tdc, phan bd ap suit, cac tdn thit BCT; tim ra sy lien quan giira cac thdng sd kdt ciu den dac tinh nang lugng, lya chgn miu canh tdt cho thuc nghiem.
Nghien cim thyc nghiem: Dung thyc nghiem de kiem chimg cac ket q u i ly thuyet, thdng qua thyc nghiem da phat hien mdt sd khac nhau giira cinh cd dinh va canh xoay, da xac dinh dugc miu canh tdt cho tua bin canh cd dinh.
De tinh toan thiet ke mat nghieng (profile) cinh BCT tua bin hudng cheo lya chgn phuong phap mdt tga dd- Phuong phap mdt tpa dp la phuong phap bidn hinh bio giac len mat ndn. Dac diem cita phuong phap nay la coi cac thdng sd cua ddng chay chi thay ddi dpc theo dudng ddng vdi gii thiet, cd the xem ddng chay tren timg mat ddng khac nhau va ddc lap vdi nhau. Cac thdng sd cua ddng chiy chi thay ddi dpc theo dudng ddng, cd nghia la nd chi phu thupc vao mpt toa do - toa do chay theo ddng chay [3],[2].
1. Tinh toan thiet ke cac BCT tua bin mo hinh Tham khao mgt sd thdng sd chinh cita BCT canh xoay da cdng bd [5], tinh toan thiet ke mdt miu chuin, thay ddi do mau ludi cinh de cd cac miu mdi, so sanh dac tinh lam viec cac miu, nhim chgn mlu canh tdi uu cho thii nghiem.
Mdu A: Chgn gdc dat canh cp = 0°; cac thong so khac tinh chgn theo tai lieu [5]. Tinh toan ton that thiiy lye va ve dac tinh ly thuyet.
Mdu B: Gili nguyen gdc dat canh cp = 0°. nhung tang ty sd 1/t 6% so vdi miu A. Tinh toan tdn that thuy lye va ve dac tinh ly thuyet.
Mdu C: Giii nguyen gde dat canh cp = 0°. nhung giam ty sd 1/t 6% so vdi miu A. Tinh toan ton that thuy lye v i ve dac tinh ly thuyet.
Tinh todn cdc mau thir nghiem: Tu miu tinh toan tdi uu a tren, thay ddi gdc dat canh cp duge cic miu mdi de thir nghiem (03 miu).
Mdu li Chgn gdc dat canh cp = 0", miu canh dugc chgn tir 03 miu A, B , C.
Mdu 2i Chgn gdc dat canh cp = 5° nhim nghidn ciiu tang kha nang thoat luu lugng qua BCT. Tinh toan tdn thit thuy lye va ve dac tinh ly thuyet.
Mdu 3A Chgn gdc dat canh cp = 5°, giam dp mau ludi canh 1/t, tang dudng kinh ra D2 ...Nham cai thien cic inh hudng do vanh ngoai cd dinh gay ra, chgn miu canh cd kdt ciu mdi tdi uu. Thdng qua cac
budc tinh toan ly thuydt de kiem tra dac tinh lim viec cita miu tmdc khi thir nghiem.
2. Thu nghiem tua bin mo hinh
Dudng kinh BCJT tua bin md hinh theo tieu chuin la 250, 300, 460 mm. Theo didu kien thyc td cita gia thi nghiem tai Vien Thuy dien va Nang lugng Tai tao, chpn dudng kinh BCTF thi nghiem la 300 mm.
Didu kien md hinh hoa dat tieu chuin Qudc te IEC 41 - 1991 - 11 ( he sd Raynol Re = 2,302.10'^ > 2.10'').
Cho phep tidn hanh thu nghiem tua bin md hinh [11,[31.
Thong so chon cua tua bin mo hinh
Sd vdng quay quy dan: n, = 90 v/ph; luu lugng quy dan: Q, = 950 1/s ; sd vdng quay dac trung cita tua bin: n, = 303,75 vg/ph; ti sd biu: d^/D, = 0,5 dudng kinh danh nghia; BCT: Dj = 300 mm ; cot nude tua bin: H = 4 m; luu lugng qua tua bin: Q = 160 1/s; cdng suit cua tua bin: N = 4,94 kw; chgn hieu suit tinh toan tua bin: T| = 90%; sd vdng quay ciia tua bin: n = 561 vg/ph.
Ban ve thiet ke chd tao canh BCT va phan din ddng cua tua bin mo hinh:
/ ^'\'4ifc
IW / 2 J 4 S J ' " '
lOien: C-C TOieti: B-B Wn: A-A
lOifn: F-F lOien, C-[ TOifn: D-D
Mat nghieng cdc ti^t diin cdnh tren mat non BHBG
28 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1/2011
KHOA HOC CONG NGHE
Dudng dac tinh tong hgp ly thuyet m^u B
Kit cau phin din ddng tua bin hudng cheo md hinh IV. KET quA NGHIEN CUU
1. Ket qua tinh toan ly thuyet chpn mlu canh a) Dudng dac tinh tong hgp ly thuyet cac miu canh
o;(i/s)
Dudng dac tinh tong hgply thuyet miu A (miu 1)
o;(i/v)
Dudng dac tinh tong hgp ly thuyet miu C
Dudng dac tinh tong hgp ly thuyet mau 2
Duong dac tinh tong hgp ly thuyet mau 3 b) Phan tich tinh toan chon miu canh toi uu:
- Mlu B so vdi miu A, hieu suit ly thuyet ldn nhit q^jax = 83,5% thip hon miu A 2,5%. Nhu vay dac tinh lim viec cita mlu B kem hon mlu A
- Mlu C so vdi mlu A, diem lim viec tdi uu thip hon, n'i= 88 vg/ph vi Q'l = 885 1/s. Nhu vay mau C cd dac tinh lam viec cd xu hudng thip hon mlu A. Qua phan tich d tren mlu A cd dac tinh lam viec tdt hon 2 miu tren, do vay chpn mlu A cho tinh toan thu nghiem tua bin md hinh.
NC . NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1/2011 29
c) Phdn tich tinh todn chon cdc mdu cdnh thuc nghiem:
Cac thdng sd chinh m l u A gdm: cac thdng sd quy din n, = 90 v/ph, Q,' = 950 1/s, gdc dat cinh: cp = 0°, hieu suit tai diem tdi uu: r\„^^ = 86,75% .
So sanh dac tinh lam viec ly thuyet 02 mlu canh thyc nghiem khi gdc dat canh cp = 0" ( miu 1) v i cp = 5" (miu 2):
- Vimg lim viec cua mlu 2 cd xu hucmg dich sang phii, luu lupng Q', tdi uu tang them 5% (997 1/s). Nhu vay kha nang thoat duge tang len, mat khac n'l cung tang. Miu nay md rgng vung lam viec cita tua bin.
- Hieu suit 1cm nhat ri,„.^.< cua miu 2 giim so vin miucp = 0"lal,5%.
- Dudng dac tinh tdng \\a\^ ly thuyet cua 2 miu cho thiy vung lam viec tdi tm phii hcrp ly thuyet tinh toan, cd the dua vao thir nghiem.
Mau 3 dugc tinh toan thiet kd tren co sd khi thi nghiem mlu 1 va miu 2 cho ket qui khdng dung tinh toan ly thuyet . Cac thdng sd chinh cua mau 3 nhu sau:Gdc dat canh cp = 5" ; giim do mau lucii canh tmng binh 1/t tai cac tiet dien: tai tiet dien mdp ngoii 1/t giam tir 1,006 xudng 0,89, tai tiet dien sat biu 1/t tang tir 1,433 den 1,59; tang ducbng kinh mep ra D2 = 0,99 D, (D2 = 298mm).
Dac tinh lam viec ly thuyet cua mau 3 nhu sau:
Tai diem lam viec tdi uu sd vdng quay quy din khdng ddi n'i= 90 vg/ph, Imi lugng quy dan tang len Q'j = 1000 1/s, hieu suit v^„,^^ = 86% khdng thay ddi. Nhu vay man 3 cd xu hucing lam viec tdt hon mau 1 va 2
(khi nang thoat tdt hon). Mlu 3 cd k h i nang khic phuc ducjc tdn tai do inh hucmg cua vanh ngoai try khi thir nghiem.
2. Kdt qua nghien o i u thyc nghiem
a) Cdc du&ng ddc tinh thuc nghiem cdc mdu cdnh tua bin mdhinh:
-t — rV ' -P& ,4 \4r •i-\-H<r~\
Dudng ddc tinh thuc nghiem mdu cdnh 2((p = 5°)
Ducmg ddc tinh thuc nghiem mdu cdnh Sdp = 5P) b) Ket qud thay doi dp mau luoi cdnh l/t cua
mdu 3 so v&i mdu 2:
1: Ti sd l/t cua mdu 1-2; 2: Ti sd l/t cua mdu 3 Bang 1. So sanh k^t qua cua mlu 3 vdi cac mlu
l v ^ 2 Mlu canh
Mlu cinh 1 Mlu canh 2 Mlu canh 3
Imai (%)
83 81,5
83
n'l tai n ^ (v/p)
80 80 90
Q'l t?d llmax
0/s)
800 900 950
Du&ng ddc tinh thuc nghiem mdu cdnh l((p = CP)
c) Phdn tich ket qud thuc nghiim
- Ket qud thuc nghiem 02 mdu ddu, mdu 1 va 2:
Viing lam viec tinh toan cua cac m i u n i m trong vimg thyc nghiem (diem lam viec tinh toan Q'l = 9501/s va n'l =90 v g / ph). Tuy nhien vimg lam vifc cd hieu suit cao nhat d ca 2 mlu cd chieu hudng dich chuyen ve ben trai v i xudng dudi so vdi diem lam
30 NONG NGHliP VA PHAT TRJ^N
N 6 N GTHON - KY 1 - THANG 1/2011
KHOA HOC CONG NGHE
viec tmh toan ly thuyet. Nhu vay khi dua vanh cd dinh vao, dac tinh cua miu canh mcM sai khae so vdi mau canh xoay. Vanh cd dinh cd the lam thay ddi ddng chay qua BCT, diem lam viee n i m ngoai vung tdi uu. Dd giai quyet vin dd nay phii nghien ciai hieu chinh va thay ddi mcit sd thdng sd ket cau cinh BCT tren co sd miu canh tren.
- Mau canh men dugc tinh toan ( mau 3) co cac thdng sd CO bin sau: Giam mat do day canh tmng bmh 1/t tai cac tiet dien; tang duong kinh mep ra D^
= 0,99D, (D2 = 298 mm). Tien hanh thyc nghiem mau canh mdi, xii ly sd lieu thyc nghiem, ve duong dac tinh tdng hpp thyc nghiem.
- Kit qua thuc nghiem mau 3: Luu lupng v i tdc dp tai tung che do deu tang. Tai do md a<, = 30 mm (tuong ung 60% hanh trinh), hieu suit dat cao nhit i],,,.,^ = 83% (bing hieu suit miu 1), Q', = 950 1/s, n', = 90 v/p. Diem lam viec thyc nghiem g i n tmng vdi diem lim viec tinh toan. Nhu vay ket qua thyc nghiem la phu hpp vdi tinh toin ly thuyet ban dau.
Mau cinh 3 la mau canh cd dac tinh lam viec tdt cho loai TBHC mdi, cinh cd dinh phu hpp cdng suit nhd, cot nude thap va trung binh.
V. KET LUAIM
1. Trong nghien cim tua bin hudng cheo (TBHC) cinh cd dinh da su dung kdt ciu tua bin md hinh khac vdi tua bin md hinh hudng cheo canh xoay nhim giai quyet bii toan phu hpp didu kien thyc td chd tao tai Viet Nam va quy md cdng suit nhd nhu:
Banh cdng tic cd vinh ngoai cd dinh hinh tru.
- Tua bin md hinh kieu true ngang, budng xoin kim loai.
(Dng hut dang cong, tiet dien trdn deu.
- Sd cinh tren BCT li z = 6 canh.
2. Vung lam viec cua miu canh moi cho hieu suit cao trong khoang Q'l = 900 - 1050 1/s, n', = 85 - 95 v/p, hieu suit q,,,,.^., = 83%. Day chinh li miu canh tdt dupe xac dinh b i n g thyc nghiem phu hpp cho TBHC canh cd dinh cot nude thip va tmng binh.
3. Ket qua tinh toin ly thuyet vi tiiyc nghiem cho ket luan: tua bin hudng cheo cd dinh vanh ngoii try trong pham vi cdng suit nhd, cot ap thap v i tmng binh H= 20-40 m
- Cd the thay the tua bin hudng true cinh cd dinh, vi vung lam viec hieu suit cao rdng hon.
- Cd the thay the tua bin tam true, vi dac tinh lam viec gin voi tua bin tam true, nhimg ket ciu binh cdng tic (BCT) don giin, sd canh it - dd chd tao (cd the thyc hien b i n g cdng nghe due lien).
- Ket q u i nghien cim buoe dau nay gdp phin cho viec nghien cuu hoin thien tua bin huong cheo canh cd dinh ap dung cho thuy dien nhd, bd sung mdt loai tua bin nira cho gam tua bin phin lye hien cd d nude ta, giup nginh co khi chd tao cd tii lieu tham khio khi che tao cac thiet bi thuy dien cho thi trudng trong nucic.
TAI UEU THAM KHAO
1- Dinh Ngpc Ai, Dang Xuan Chi, Nguyen Phude Hoang, Pham Due Thuan. "Thuy lye va miy thuy lue". Tap 1 v i 2. NXB - DHTHCN - 1972.
2- Le Danh Lien, Vo Sy Huynh. Ly thuyet canh.
NXB- DHTHCN - 1977.
3- Vo Sy Huynh, Nguydn Thi Xuan Thu. Tua bin nude. Dai hpc Bach khoa HN-1991.
4- Toshiba engineering. Micro hydro power generating equipment. Tokyo - 2001.
5-KBTKOBCKnfi B. C. Jiia,xj!ia:ibHbie cudpomvpowibi.
MsATe.ibCTBo "MaujimocTpoeHiie", MocKsa, 1971.
(> KBHTKOBCKIIH B. C , PaooNuii npoijccc oceeoii ciidpomypduubi. H.1, Tp\abi BHTM, obin. XIV, 1951.
SOME RESULTS OF FIXED - WINGS DLVGONALTURBINE RESEARCH TO SERVE SMALL ' • HYDRO IN VIET NAM
Pham Phuc Yen, Bui Quoc Thai Summary
This article presents results of research on a new turbine, fixed-wings diagonal turbine, in scale small power, low and medium head. Its runner has simply stmcture, high productivity. On above scope, it can be replace Francis turbine and fixed-wings Caplan turbine. .Moreover, it is suitable for producing ability in Vietnam. Working specifications of turbine model are flow Q',=9001050 1/s, velocity n',=8595 rpm, maximum |ii'oductivit\' ii„„,= 83%. Working range: power 801000 kW; head 2040 meter.
Keywords: Diagonal turbine, hydropower station, small size capacity.
Ngudi phan bien: PGS.TS. Vo Sy Huynh.
NO- ' 9 NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1/2011
