NGHIEN cufu - TRAO OOI
^ NGHIEN CUU VADE XUAT BO THONG S6 CONG NGHE PHUC VU THUG NGHIEM Ot NANG CAO HIEU S U A T THier Bj LOG BUI TTNH DIEN TRONG NHA MAY NHIET DIEN THAN
RESEARCH AND SUGGEST TECHNOLOGY PARAMETERS FOR EXPERIMENTAL WORK TO ENHANCEMENT EFFECT OF ELECTROSTATIC FILTER IN FIRED COAL POWER PLANT
ThS. Trieu Quy Huy', PGS.TS. Hoang Van Gat' 'TrUdng Dai hoc Viet Bac 'Vien Nghien ciiu Cd khi, Bp Cong Thuong TOlU TAT
l/u diem chinh cua thiet bj Igc btii tinh dien (LBTD): Hieu sudt khd bui cao, co the dat tdi 99%, ton thdp dp lUc be, tieu hao dien ndng be, lUOng khoi chda hui di qua thiet bi ldn, chiu nhiet dd cao. dk dieu khien tii dgng hoa. Vi vdy, LBTD dang dUdc sd dung rong rdi trong nhd mdy nhiet dien than. Hieu sudt cua LBTD phu thugc vdo nhieu nhdn to nhU; Hdm lUdng bui vdo, van toe dong khi hui, luu lUdng dong khoi bui, tong dien tich be mdt tich bui, tinh chdt dong khi cdn loc, kich thUdc htit bui, chieu day ldp hui tren tdm ciXc thu, dien trd sudt cua bui, cUdng do dien trudng...[2]. Viec nghien cdu luachgn mgt so thong sd chinh cho khdo sdt de xdc dinh ddi gid tri phu hdp nham ndng cao hieu sudt LBTD Id vdn de rdt quan trgng trong cong tdc van hdnh.
Tif khoa: Thiet hi Igc bui tinh dien; Hieu sudt loc hui.
ABSTRACT
Main advantage of Electrostatic filter (ESP) follow; Hight effect which is obtainable to 99%, lower pressure loss, lower electrical energy expenditure, big flue dust rate; hight automatism...
Therefore, ESP have being to use much in Fired Coal Power Plant (PCPP). ESPs effect on dependence of many factors; Input dust content, speed flue dust, flue dust rate, dust surface area, filted gaz quality, dust element dimension, dust layer thickness on negative plate, dust electric resistivity electricfield,...l2j.
Learning main technology parameters to explore for defining amount rational area of them. ESPs effect enhancement is very impotant problem on ESP operating work.
Keywords: Electrostatic filter: Dust filter effect.
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NGHIEN cufu - TRAO D O I
l . D A T V A N D E
Hien nay, tai niiofc ta cd hang tram nha may dang stf dung thiet bi lpc bui tinh dien nhap ngoai nhif nha may nhiet dien than, nha may san xuat vat lieu xay diing,... Gia thanh mdi TBLBTD, tuy theo cdng suat cd the tdi vai chuc trieu do la My. Cd nhieu giai phap de lam tang hieu qua thiet bi nhU; Giai phap thiet ke, giai phap nang cao dp chinh xac che tao va lap dat he ciic thu bui, giai phap liia chpn che dp van hanh, giai phap han che ham lUpng bui vac,...
Viec nghien cilu tim ra glai phap xay diing che dp lam viec de nang cao hieu su£t LBTD trong di^u kien cua niidc ta dang sii dung thiet bi nhap ngoai la can thiet va phu hpp. De liia chpn mdt sd thdng sd cdng nghe chinh phuc vu khao sat thiic nghiem nham nang cao hieu suat thiet bi, can phai nghien ciiu, phan tich cac nhan td
^nh hiidng tdi hieu qua sii dung thiet bi.
2. NGUYfiN L i T H U BUI TRONG THIET BI LBTD
Lpc bui tinh dien (LBTD) la he thdng lpc bd cac hat bui cd kich thUdc nhd khdi ddng khdng khi chay qua budng lpc, tren nguyen ly ion hoa va tach bui ra khdi khdng khi khi chung di qua vung cd trudng dien ldn. Budng lpc bui tinh dien diioc cau tao hinh thap trdn hoac hinh hpp chii nhat, ben trong cd dat cac tam ciic song song hoac cac thanh thep gai. Hat bui vdi kich thiidc nhd, nhe bay lo lifng trong khdng khi diiOc diia qua budng lpc cd dat cac tam ciic. Tren cac tam ciic, dUpc cap dien cao ap mOt chieu cd til vai chuc cho den lOOkV de tao thanh mpt dien triidng cd ciidng dp Idn. Hat bui khi di qua dien tnidng manh se bi ion hoa thanh cdc phan ttf ion mang dien tich am sau dd chuyen ddng ve phia tam cUc dUOng va bam v^o tam ci^c dd. Bui se diioc tach khdi cac tam ciic bdng vi?c rung rH tam ciic. So dd nguyen ly
tich bui trong buong lpc (hinh 1), [3], [4].
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Hinh 1: Sd do nguyen lythu bui trong loc bui tinh dien:
a) Sd do nguyin ly tich bui;
b) Sd do nguyen ly bo tri cdc bdn cUc 3. CAC NHAN TO ANH H U 6 N G T C H HIEU QUA CUA THIET BI LBTD
3.1. Nhan td tinh chat khi can Iam sach Tinh chat khi can Ipc can hieu la dac tinh ciia bui cd trong khi nhii kich thUdc hat bui, tinh chat hat bui. Loai bui di qua budng lang khac nhau thi kha nang tich dien cung khac nhau, dieu do co the lam giam dien ap tren dien cUc sang, dan den lam giam dien ap tren hai ban cUc va hau qua ISng bui kem. Kich thudc hat bui anh hUdng tdi kha nang thu bui (dd thj hinh 2),[3], [4]. Ca hai dac tinh tren deu
giam hieu suat thiet bi [2].. ^
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NGHIEN Cljru-TRAO Ddi
Do vay, nhdm III thu bid kem. Anh hddng dien trd suat tdi hieu suat thu bui t h i hien tren hinh 3.
Hinh 2: Do thi sii dnh hUdng cua kich thUdc hgt bui tdi hieu sudt loc cua mpt so dgng bdn ciic
3.2. Anh hitdng cua ldp bui tren cac dien ciic Ldp bui bam tren cac ban cUc, chii yeu la ciic lang, ldp bui bam cang day se lam giam cUdng dp dien gifla hai ban ciic, d i n tdi lam giam kha nang bam bui tren cUc l&ng va hieu suat lpc bui giam.
3.3. Anh hiidng cua dien trd suat
Dp dan dien (dien trd suat) ciia ldp bui tren cac ban ciic anh hUdng tdi kha nang tich bui ten cac ban ciic. Bui chufa trong khi dUpc chia thanh 3 nhdm [3]:
- Nhdm I: p < 10 ''Cera: Khi lang vao cac dien cUc, cac hat bui bi mat dien tich ngay nen cd the bi cuon di lan nUa theo khi, bui khdng bi lang tren ban cUc;
- Nhdm II: p = 10-* ^ I.lO'^n.cm: Lpc bui tinh dien khii tdt nhat, vi ling vao dien cUc, cac hat khdng bi mat tinh dien ngay nen cd du thdi gian tao thanh ldp. Do vay nhdm dien trd suat II la dieu kien thu bui tdt;
- Nhdm III: p > 2.10"'a.cm: Lpc bui tinh dien khif rat khd. Bui thudc nhdm nay khi lang vao dien cUc se tao thanh ldp bui xdp each dien. Khi cUdng dp dien trUdng tang len den gia tri tdi han nao dd se xay ra phdng dien qua ldp bui xdp de tao thanh ranh nhd chiia day cac ion dUOng.tiep theo se la hien tUpng phdng dien.
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Hinh 3: Do thi dnh huSng diin trd sudt tdi hieu suat thu bui
3.4. A n h hiidng cua h a m Iticfng bui b a n dau LUdng bui dau vao buong lang cao, lam giam dang ke cUdng dp ddng dien trong buong lang, hien tUdng nay lam giam kha nang thu bui dang ke.
3.5. Anh cua nhiet do t6i hieu suat loc Nhiet dp trong budng lpc anh hiidng nhieu tdi hieu suat thiet bi, khi nhiet dp ddng khi giam thi dp nhdt ddng khi giam, dieu nay dong nghia vdi liic can tac dung len cac p h ^ tii tich dien khi di chuyen ve cUc lang giam, dp on dinh dien tang trong viing phdng dien tich dong thdi giam dien trd suat cua bui. Sii phu thudc cua hieu suat vao nhiet dp dUpc the hien tren hinh 4, [4].
^
FTinh 4: Do thi sU dnh hUdng ciia nhiit dp tdi hiiu sudt loc bui
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NGHIEN ClIU - TRAO D O I
3.6. Anh hifdng cua v4n t6c di chuyen phSn tufbui
Van tdc di chuyen cua phan tif bui anh hudng dang ke tdi thu bui cua ciic lang, khi van tdc tang, ddng nang tang, lam giam hieu qua hut bui cua tam ciic thu, khi van toe giam thi hieu thu biu tang, hieu suat tich bui tang. Md hinh toan hpc the hien cdng thdc...(1), [2].
= qE/37t^d (1)
Lien he gida van tdc di chuyen bui (v) va hieu suat lpc bui, the hien tai cdng thiic (2), [2]:
p = e-v^Q (2) Trong dd: v: Van tdc di chuyen cua bui,
cm/s; [i: Dp nhdt khdi, g/cm.s; q: Dien tich ciia hat bui; E: CUdng dp dien trudng, Kv/cra; d:
Dudng kinh hat bui, cm, Q: LUu lUpng ddng khdi cd bui, mVs; A: Tong dien tich be mat tich bui, m l
4. DE XUAT MOT SO T H 6 N G SO PHUC VU K H A O S A T D E NANG CAO HIEU SUAT Tf CH BUI
Cac thiet bi lpc bui tinh dien dUpc nhap ngoai, dang dUpc sii dung tai cac nha may cdng nghiep tai Viet Nam nhU nha may nhiet dien than, nha may san xuat xi mang,.. .deu do nUdc ngoai hudng d i n van hanh, dUa vao sil dung.
Trong qua trinh sii dung da phat sinh nhflng van de can dieu chinh cac thdng sd cdng nghe cho phu hpp, vi du: Thay loai than dot,...Do vay, chiing ta can Iam chu viec liia chpn cac thdng sd ky thuat de nang cao hieu qua cho thiet bi.
Cac thdng so co kha nang dieu chinh dUpc nhU:
LUu lupng ddng khdi, van tdc di chuyen ciia
bui, ldp bui bam tren ban cUc tich bui, nhiet dp ddng khi bui, cUdng dp dien trUdng,...De lUa chpn dupc cac gia tri cua thdng sd ky thuat, cdng nghe van hanh thiet bi can phai thiic hien bang thUc nghiem tren thiet bi va dilu kien thUc tien. So sanh cac hieu suat lui bui vdi cua cac bp thdng sd ky thuat, cdng nghe khac nhau, lam CO sd quyet dinh.
5. KET LUAN
Tfl ndi dung neu tren cd the riit ra ket luan sau:
Da phan tich dviac ndi dung chinh ve ban chat cua cua qua trinh tich bui vao cac ban cflc trong buong Ipc la d dieu kien dien ap mdt chieu cao, cd tfl vai chuc cho den lOOkV de tao thanh mot dien trfldng cd cfldng dp ldn. Hat bui khi di qua dien trUdng manh se bi ion hoa mang dien tich am sau do chuyen ddng ve phia tam cUc duong va bam vao tam cUc dd. Bui se dupc tach khdi cac tam cUc bang viec rung ru tam cUc.
Da luan giai cac nhan td chinh anh hudng tdi hieu suat thiet bi LBTD nhU: Ham Iflpng bui vao, van toe ddng bui, lUu Iflpng ddng khdi bui, dien tich be mat tich bui, tinh chat ddng khi can Ipc, kich thflde hat bui, chieu day ldp bui tren tam cflc thu, dien trd suat ciia bui, cUdng dp dien trUdng. Tfl dd da khang dinh dung phfldng phap thUc nghiem cho Ifla chpn bd thdng sd ky thuat, cong nghe de nang cao hieu suat loc bui.
Ket qua nghien cdu cd the cung cap dfl lieu cdng nghe quan trpng cho cdng tac thiet ke
thiet bi loc bui tinh dien. • "^
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NGHIEN cdu - TRAO ePi
Ngay nhan bai: 05/7/2014 Ngay phan Men: 20/8/2014
Tai li^u tham khao:
[1]. Vien Nghien ciiu Co khi (2012), Nghien cdu thiet ke che too vd dUa vdo vdn hdnh loc bui tinh dien cong sudt 1.000.000m3/h.
[2]. GS,TSKH. Nguyen Sy Mao (2008), Mdi trUdng vd ky thuat xd ly chdt phdt thdi NXB. Khoa hgc vdKy thuat.
[3]. Hoang Kim Co (1999), Ky thuat loc bui vd lam sach khi. NXB. Giao due.
[4]. Hoang Kim Co (2002), Tinh todn ky thuat loc bui vd ldm sach khi. NXB. Khoa hoc va Ky thuat.
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