Caáu Taïo – Vaän Haønh Tuabin hôi

8/14/2019 Cau Tao Van Hanh Tuabin hi

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Cau tao van hanh tuabin hi Chng 9

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Chng 9 CAU TAO VAN HANH TUABIN HI

9.1 CAU TAO TUABIN

Ve mat cau tao, tuabin co cac bo phan chnh sau:

1. Than 2. Rotor3. Canh quat 4. Palie va palie chan5. Bo chen truc 6. Noi truc7. Thiet b bao ve 8. He thong dau

1. Than tuabin

La bo phan tnh c ban cua T, ben trong co gan cac nhom OP

tang C, banh tnh, canh tnh (hay vanh mang canh tnh), bo chen +chi tiet khac. T ac iem sc ben va cong nghe che tao, hnh dangthan T phai sao cho n gian va oi xng theo hng doc truc.

Hnh 9-1: Than tuabin

1. Na di 2. Na tren (nap) 3. Mat bch ghep noi 4. Ni gan cum VC5. Ong thoat hi 6. Cac console 7. Chot nh v than vi palie

Than gom hai na (tren va di). oi khi ngi ta chia than theohng ng: de gia cong + kha nang s dung vat lieu thch hp chotng phan. Viec lap ghep cac phan cua than phai rat can than v nhieto cho ghep noi khong ong eu, co the xuat hien khe h khi vanhanh lam ro r hi.


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Trong tuabin XL nhieu khi ngi ta khong at banh tnh vao thanma gan vao mot cai e trung gian roi sau o mi lap toan bo vaoranh trong than.

Hnh 9-3: Vanh mang canh tnh1. Than 2. Vanh mang canh

- Kha nang dung mot than chung cho vai tuabin cung kieuco cong suat khac nhau.- Ket cau than n gian giup gia cong thuan li hn nhieu.- Kha nang thay the tng vanh, neu co h hong.- De dang bo tr cac ca trch hi.- Gia nhiet than may thuan li va de ong eu.

e than khong qua dayva cac bulong ghep khongln qua mc, than CA (p >15 MPa) co the lam hai lp.

Than hai lp tuy co kchthc ln, nang ne hn, giacong phc tap nhng giamc be day moi lp vo, tangkha nang an hoi

H.9-2: Than CA hai lp1. Vo ngoai 2. Vo trong3. Ong hi vao 4. Ong hi ra5. Cac then va chot nh v

Tuabin FL : canh tnh cgan trc tiep vao ranh trong

than. Gan ay co xu hnggan tng nhom canh len vanhmang canh rieng treo trongthan (H 9-3).

Li ch cua vanh mangcanh la:


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Cac OP tang C c bo tr phan trc than, ngay sau buonghi vao. Chung xep lien nhau thanh nhom tuy theo so lng VC.e de che tao va sa cha, thng gan cac nhom OP tren mot vanhhnh mong nga.

Ket cau than T phai bao am kha nang xa nc triet e moi vtr ma hi co the ngng tu va ong lai, nhat la luc khi ong may.Boc cach nhiet can than.

2. Rotor

Rotor gom truc, banh ong va canh quat gan tren banh (hoac ganlen tang truc). Ve mat ket cau co the phan rotor theo hai nhom:

Rotor kem cac banh ong; Rotor kieu tang trong.

Rotor nhom 1 s dung cho tuabin XL. No la mot chi tiet tien, H.9-4a; ph/an nay gii han cho ti 800 mm. Khi ln hn th tngbanh ong c che tao rieng, sau o lap gang vi truc (H. 9-4b).

Hnh 9-4: Rotor co kem banh onga) Banh ong lien khoi vi truc b) Banh ong ri

Rotor kieu tang trong: cho tuabin FL. Khi u < 200 m/s, co theche tao rotor t mot vat uc (hnh 9-5a). Thng khoan mot lo daitheo truc e kiem tra chat lng uc. oi vi T ln th rotor c hant nhieu chi tiet uc gia cong rieng re (hnh 9-5b).


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Hnh 9-7: Mot so kieu chan canh

Vat lieu che tao phai la thep chat lng cao. Loai thep c sdung rong rai la hp kim cha 13% Cr vi ham lng C thap. ieu

kien nhiet o cao th thep nay c bo sung them Mo hay Va.

4. Palie va palie chan

Palie

Moi rotor T at tren hai o trt c boi trn bang dau tuanhoan. Khi T lam viec, ngong truc quay trong lp dau boi trn, ma satsinh ra la MS t. o ln cua MS nay phu thuoc vao o nht dau,

khe h trong palie va tai trong tac dung. NL ton hao do MS lam nongdau, v the dau boi trn am nhan ca chc nang lam mat. Nh co lpdau ngan cach, ngong truc va lot o (cutxine) khong trc tiep tiep xucvi nhau nen khong b mai mon.

Palie kieu xecmang va palie lo ovan co kha nang giam rung tothn loai lo tron nh s phan bo ap suat on nh hn va mang dau boitrn khong b t.


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Hnh 9-8: Cac dang cutxine

Cutxine la chi tiet uc, mat trong c trang mot lp hp kimchong mon goi la lp babit. Lp babit se giam MS khi lam viec, giamo gia nhiet va o mon cua ngong truc.

Dau tuan hoan vao palie co tv = 40 45 oC se b nong len themkhoang (12 15) oC. Yeu cau tra khong qua 60 oC; lu y ay la ttb, taimot vai v tr cuc bo trong cutxine nhiet o mang dau rat cao.

Palie chan

Palie chan dung e chu lc doc truc, thng la loai palie gomnhieu tam chan ap len be mat a chan cua truc. Khi truc quay, cac

tam chan nghieng theo a chan tao nen nhng nem dau tren be mata chan khien a khong the tiep xuc vi tam chan.

Palie chan co the c bo tr rieng biet, nhng ngi ta thngket hp vi palie nh mo ta tren hnh 9-11.

Kiem soat nhiet o dau ra khoi cutxine la viec rat quan trong.Neu to tang qua mc, tnh nht cua dau giam xuong, che o MS tco the chuyen sang MS na t lam he so MS tang vot len. Hau quala lam chay palie. e han che h hong khi co s co, tren be mat cactam chan co mot lp babit. Ban than tam chan cung c che taobang KL co kha nang tiep tuc lam viec sau khi lp babit a chay.


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Hnh 9-11: Ket hp palie chan vi palie 1. Than palie 2. Xecmang o chan 3. Vong chan 4. Mieng em

5. Vong chen dau 6. Vong cach 7. Be palie

5. Bo chen

V du ve ket cau bo chen lat leo c mo ta hnh 9-12. Motloat ranh va bac tien tren stator ket hp vi cac la kim loai mong gantren rotor tao ra he thong rang lc co khe h hng knh rat be.Cung co the gan rang chen ve pha stator. Cac khe h hng trucphai u ln, cho phep o dch chuyen tng oi nhat nh gia R viS. V yeu cau phai gia cong chnh xac nhng bac chen, ngi ta

thng bo tr chung tren mot chi tiet goi la vanh chen. Cac rang chenc che tao t kim loai mong, mem e phong khi R va cham vao Sth chung ch b quyet nhe, khong sinh ra nhiet qua mc va khonggay h hai cho truc T.


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Hnh 9-12: Mot kieu chen truc1. Than tuabin 2. Vanh chen 3. Truc 4. Rang chen 5. ai xiet

6. Noi truc

Hnh 9-13: Noi truc cng Hnh 9-14: Noi truc na cng

e lien ket truc T vi truc G ngi ta dung cac loai noi truc:cng, na cng, khp rang va noi truc mem. Noi truc truyen cong suatt cac rotor T en rotor G, chu phu tai ln va quay vi n cao. Ngoai

cac ng lc do tac dung ly tam cua cac chi tiet, con xuat hien cac ngsuat co dau thay oi, ng suat va ap va cac ng suat khac.

Loai noi truc mem: chu yeu la khp lo xo, co the truyen ongquay t na khp nay sang na khp kia. T hien ai khong dung loainay na v hay b mon, kho bao am ung v tr cua cac lo xo, khocan bang ong va gay tr lc ang ke khi truyen momen xoan ln.


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e quay T khi khi ong va sau khi dng may nham giup chophan bo nhiet o trong T ong eu va tranh b cong truc ngi tadung bo quay truc (con goi la bo tr lc). TB quay truc lam viec theonguyen ly c hoc, thuy lc hay ien. bo quay truc c kh, rotor Tc truyen ong nh ong c ien thong qua hop giam toc lien ketvi noi truc bang banh rang (xem hnh 9-13 va 9-14).

7. Thiet b bao veThiet b bao ve thng tac ong ong van stop va cac xupap

VC khi co s co e ngng ngay tuabin.Mot so bo phan quan trong bao ve T co the ke la:

- Chot an toan e bao ve tuabin khi vt toc.- Rle di truc chong o di truc cua rotor vt qua mc.- Bo phan gi ap suat dau ieu chnh va boi trn khong oi.- Bao ve chan khong trong bnh ngng.

Bo phan bao ve quan trong nhat la chot an toan at trong truc T,hnh 9-16. Trong tam cua chot khong nam tren tam truc T. Bnhthng th lc nen cua lo xo can bang vi lc ly tam. Khi n tang vtgia tr cho phep, lc ly tam cua chot thang lc lo xo, chot vang ra ap

vao can truyen ong trung gian e ong van stop, ngat hi vao.

Hnh 9-16: Chot vang an toan1. Chot 2. Lo xo

3. Rotor T. Trong tam chot

Hnh 9-17: Vong an toan1. Vong lech tam 2. Lo xo

3. Truc tuoc bin


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Mot kieu bao ve an toan khi vt toc khac la vong an toan (hnh9-17). Vong lech tam c lap ben ngoai truc. Bnh thng th lo xoep vong bam vao truc; khi n tang en gia tr ti han, lc ly tam selam vong dch chuyen vi khoang chay a.

8. He thong dauDau T dung e boi trn va lam mat cac palie, ong thi cung cap

NL cho he thong ieu chnh. S o dau pho bien ve tren H.9-18.

Hnh 9-18: S o he thong dau

Dau c bm dau chnh bm t be cha. Ch mot phan nho dauvi ap lc toan phan (3 6) bar i ti cac bo phan ieu chnh va baove; phan ln con lai c giam ap xuong khoang (1,3 2,0) bar +lam mat trc khi ti nhng v tr can boi trn. Thng lam mat dau

bang nc ngng. Lng dau d c hoi ve thung cha qua nga vanhoi lu. e phan phoi chnh xac lng dau cho tng palie, trong cacong dan dau nhanh co at vong tiet lu.

Trong qua trnh khi ong va ngng T, do n thap, bm dau chnhkhong bao am c lu lng va ap lc dau can thiet nen phai cobm dau phu. Bm dau phu c keo bang mot tuabin nho at ngay

1. Bm dau chnh 2. Van giam ap

3. Van hoi lu 4. Bnh lam mat dau

5. Bm dau phu 6. Thung dau


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tren be dau va t ong chay khi ap suat trong he thong giam xuong.Ngoai ra con co bm dau s cochay bang ong c ien.

9.2 VAN HANH TUABIN HI

Nhiem vu: cung cap ien va nhiet nang lien tuc, am bao chatlng, an toan, vi o tin cay cao va hieu qua kinh te toi a.

Trnh t + cac thao tac van hanh cu the c ghi trong Qui trnhvan hanh lap rieng cho tng loai T.

Noi dung qui trnh van hanh co ba phan:

1. Gii thieu ac iem chung ve cau tao thiet b.2. ac tnh ky thuat cua thiet b.3. Hng dan van hanh.

Van hanh tuabin la thc hien cac cong viec:

- Kiem tra, chuan b ieu kien van hanh.- Chuan b khi ong.- Khi ong.- Kiem soat thiet b khi lam viec bnh thng.-

Ngng thiet b.Trong muc nay chung ta ch xem xet mot so van e c ban canlu y khi khi ong va ngng thiet b. ay la hai giai oan quantrong trong van hanh tuabin v luc o trang thai c hoc va nhiet cuacac bo phan, chi tiet tuabin va ng ong dan thay oi rat ln.

1.Khi ong tuabin Khi ong t trang thai nguoi

a. Say ong dan hiOng c say bang cach t t m van a hi vao. Neu m van

nhanh se lam KL ong chuyen ot ngot t lanh sang nong tao ra ngsuat do gian n nhiet; nc ngng tu b dong hi cuon i vi van tocln gay hien tng thuy kch (bua nc) lam ong rung ong manh cothe dan ti hau qua nghiem trong nh t cac moi han, bat bch noi.


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Toc o say ong phu thuoc vao TSH mi va s o ong hi chnh.Cac van xa tren oan ong say phai m e kp thi xa nc ong dohi ngng tu trong ong; ong xa con lam nhiem vu lu thong hi say.

Trc khi say ong can nh quay truc tuabin lien tuc e tranh

trng hp co hi ro vao lam rotor nong khong eu gay cong truc.Cung v ly do o phai he m van nc tuan hoan e lam mat ong BN,phong khi khi ong T m nc vao ot ngot gay hong ong.

b. Tao chan khongCung vi viec say ong can tien hanh tao chan khong trong bnh

ngng nh ejector khi ong. Luc o phai chay bm ngng e capnc lam mat hi ejector.

c. Xung ong rotorLa ong tac a nhanh hi vao T cho rotor quay n qui nh

(khoang 300 500 v/ph) e say T.

Trc khi xung ong phai chay bm dau phu e cap dau boitrn. Sau khi xung ong can kiem tra lng dau ra cac palie va ngheam thanh trong may.

d. Gia nhiet tuabinTang dan n theo tng cap vi thi gian qui nh cho ti khi at n

nh mc e say T. Neu thc hien qua trnh say khong tot co the xayra nhng hau qua:

- Xuat hien ng suat nhiet trong than T va cac VC.- Cong venh do gian n cua than tren va than di khong eu.- Rotor b rung do ng suat nhiet.- S thay oi kch thc dai gia rotor va stator khong tng

ng co the dan en va cham.- Thay oi ng suat cho lap ghep cac chi tiet tren rotor.- ong nc trong T gay ra thuy kch.

Qua trnh say T thng c chia thanh ba giai oan:

- Giai oan say so vong quay thap (300 500 v/ph).


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- say n trung bnh (1000 1200 v/ph).- say va nang n ti nh mc.

Thi gian duy tr tng mc so vong phu thuoc CS tuabin, TSHban au va toc o say cho phep cua kim loai. Khi nang n ma xuat

hien rung qua mc phai giam n cho en het rung va say tiep e cheo nhiet ong eu hn. giai oan ba can chu y vt nhanh qua n tihan, luc o rung cua rotor tang vot. Khi n gan ti nh mc (khoang2600 2700 v/ph) cung nen nang nhanh e cho bm dau chnh lamviec han, sau o th ngng bm dau phu.

e. Kiem tra va th nghiemSau khi n at gia tr nh mc can kiem tra tnh trang va cac

thong so cua thiet b nham khang nh rang tuabin hoat ong bnhthng va co kha nang mang tai. Th nghiem tac ong cua cac bophan bao ve nh: an toan khi vt toc, bao ve di truc,

f. Nhan phu taiLuc nay tan so quay cua thiet b tuabin c hoa vi tan so li

bang bo phan ong bo, may phat c kch thch va noi vao liien. Van hi chnh m hoan toan, cac van xa va van nhanh th ong.

Cac van ieu chnh t ong m e t t tang tai. giai oan nhan tai, trang thai c nhiet cua tuabin con tiep tuc

thay oi. V the toc o nang tai cung c xac nh bi che o saytuabin va cac tieu chuan o tin cay. Noi chung, toc o nang tai tuabinthng khong qua 1% cong suat nh mc trong mot phut.

Trong QT nang tai neu phat hien s rung ong bat thng thphai ngng nang va duy tr phu tai khong oi cho ti khi het rung.

Khi T at en cong suat nhat nh th bat au cho he thong GNnc cap lam viec.


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Hnh 9-19: Bieu o khi ong

ac iem khi ong tuabin t trang thai ac bietKhi ong T t trang thai nong

T coi la nong (cha nguoi) neu nh.o phan nong nhat con qua150 oC, may mi dng di 30 gi. Khi dng, T mat nhiet dan nenphai quay truc e rotor c lam nguoi ong eu. Thng la na thandi nguoi nhanh hn na than tren nen than may va rotor co xuhng b cong len. Ngoai ra trang thai nhiet cua cac bo phan T khacnhau do mc o nguoi nhanh cham khac nhau. V vay viec khi ongT t trang thai nay phai rat than trong.

Trc het say s bo nhng bo phan hay chi tiet a b nguoi nhieuhn nh cac tuyen ong dan hi, van hi chnh, van stop QT say sbo c coi la ket thuc khi nhiet o cua cac bo phan o gan bangnhiet o kim loai than T. Tiep theo la a hi vao T e nang n. Thigian nang so vong can giam xuong toi thieu nham giam bt toc onguoi cua phan cap hi va o say nong phan cuoi than ha ap.


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Khi ong tuabin vi thong so trt

ay la PP khi ong tuabin cung luc vi khi ong lo hi, cthc hien cho to may thuoc s o khoi (mot LH noi vi mot T): ahi thap ap sinh ra t lo e say T ngay.

Luc khi ong, tat ca cac van tren ng ong hi chnh t LHen T cung nh cac van xa tren ng ong o eu m hoan toan. Khi

p at (3 10) bar tuy T ln nho th bat au xung ong rotor. Nhvay trong QT khi ong viec say cac ong dan hi, van va T c tienhanh ong thi bang hi co nhiet o va phai.

Khi ong T theo thong so trt co nhng u iem:

- Thi gian khi ong ngan v viec say van, ong va tuabinong thi ch khong tuan t nh khi ong vi thong so nh mc.

- Giam chi ph nang lng khi khi ong.- Giam ton that nhiet ra moi trng nh thi gian khi ong

khoi lo tuabin ngan.

- Cach khi ong nay an toan v chenh nhiet o gia hi sayva kim loai nho, tranh c tac hai do KL b nong ot ngot.

2.Ngng tuabinGiai oan ngng T cung rat quan trong, de sinh ra s co. V vay

viec ngng may phai tien hanh than trong va ung QT.

a. Ngng may bnh thng. Gom cac cong viec:

Giam cong suat. Trong QT giam phu tai can theo doi:- o gian n dai tng oi gia rotor va stator.-

Trang thai rung cua tuabin may phat.- Chenh lech nhiet o gia cac phan than tuabin.- Mc nc trong bnh ngng.- He thong hi chen truc.- Nhiet o dau ra t cac palie.


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Ngng tuabinSau khi giam het phu tai th tach may phat khoi li. T.ong len

chot an toan e ong VC va SV cat hi vao T. Sau khi dap chot antoan, T con quay theo quan tnh, ta phai ghi chep o giam n va

th.gian chay theo a cua may. Th.gian chay theo a ac trng cho ohoan hao cua T, bnh thng khoang 20 25 phut cac T ngng nho,30 35 phut oi vi T ln. Khi n bat au giam th bm dau phu tong lam viec, luc nay can k.tra can than AS dau boi trn va sh.ong cua bm dau phu.

Trong thi gian chay a oi khi phai giam bt chan khong (bangcach giam hi chen) e rotor ngng nhanh hn.

Cong viec sau khi rotor ngng quaySau khi rotor ngng han phai cho thiet b quay truc lam viec lien

tuc trong 8 gi au. Tiep theo nh ky tr rotor 180 o cho en khi maynguoi han. e e phong lp babit trong cac o truc khoi b chay vadau boi trn khong b nong qua ta phai cho bm dau chay tiep,khoang 30 40 phut oi vi T trung ap va 4 8 gi oi vi T cao ap.

Co nhieu muc ch ngng T khac nhau: e d phong, e sacha hay ngng lau dai. Neu ngng lau dai th phai thc hien che o

phong mon e ngan nga s an mon cua hi va khong kh.Ngng may do s co

Nhng s co xay ra bat buoc phai ngng may eu c ghi rotrong QTVH cho tng loai T.

Neu s co khong nghiem trong lam th co the ngng may theotrnh t bnh thng. Nhng neu s co nguy cap th phai ngng mayngay cang nhanh cang tot. Muon ngng may nhanh th sau khi ap

chot an toan phai pha hoai chan khong trong BN nham tao them lccan, giam th.gian rotor quay theo quan tnh.Viec ngng may pha hoai chan khong la viec bat ac d, v no

lam cho phan uoi T b nong qua mc, co the gay nen h hong dong suat nhiet gay nen. Ch AD cho nhng trng hp that khan capva c ghi ro trong QT chong s co.

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Caáu Taïo – Vaän Haønh Tuabin hôi