NGHIEN cuu-TRAO DOI
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va cOng ngh$ ch^tao thigt bj true vA sA uyng khi hydro
(*) TS NGUYEN KHAC B A N G
KS NGUYEN VIET HUNG (**) PGS-TS BUI NGOC HOI
1. MO DAU
Thiet bi true vdt (TBTV) cac vat chim dudi nudc dugc che tao va sir dung theo nhiing nguyen ly khac nhau. Thiet bi true vdt sir dung chat tao hydro la mgt hudng cdng nghe tien tien dang dugc nghien ciiu va cd nhieu trien vgng, dac biet la de true vdt cac vat bi chim d do sau Idn.
Hgp tac vdi cac nha khoa hgc Vien Cac van de Che tao may (Vien Han lam Khoa hgc Ukrauie), nhdm nghien ciiu thudc Vien Phat trien Cdng nghe - Truyen thdng vaHo trg Cdng ddng (Lien hiep Cac Hgi KH&KT Viet Nam), da che tao thir nghiem thanh cdng thiet bi true vdt sir dung khi hydro.
Bai bao trinh bay nhiing dac diem ve nguyen ly hoat ddng ciia TBTV va thiet ke che tao cac thanh phan CO - dgng luc chu yen cua TBTV (Khoang sinh khi, phao chiia khi va ca cau ghep ndi).
2. NGUYEN LY HOAT DONG CUA TBTV SU*
DUNG KHI HYDRO
Hinh 1, md ta can tnic tdng the va nguyen ly hoat dgng cua TBTV sir dimg khi hydro tao trong mdi tmdng nudc:
Dau do tim
PHAO CHLTA KID HYDRO
^ p t O ANG TAO KHI
tJlYDRO IJ
CO CAU GHEP NOI
TRUNG TAM DIEU KHIEN
Hinhl
(*) Vien Phat tnin Cong nghe - Tmyen thong va H6 trp Cpng dpng (**) Vien Khpa hpc & Cong nghe Quan su
Nhiing bd phan ca ban cua TBTV bao gom: Khoang tao khi hydro; Phao chira khi hydro; Ca can ghep ndi, Thiet bi dd tim (tir tinh va quang hgc) va Trung tam dieu khien.
Bg phan quan trgng nhat cua TBTV la ong kim loai hinh tru dugc thiet ke dam bao do can bang ddng hgc vdi hai phan ket ndi chat che vdi nhau la khoang tao khi hydro va phao chiia khi hydro. Thiet bi (dau) dd tim cam iing tir va quang hgc gan chat phia ben canh, sat day dudi cua khoang tao khi hydro, dam bao gdc va cu ly quan sat, dd tim hgp ly. Co cau ghep ndi (tay may thiiy khi) dugc gan ket chat che vdi phan dudi cua khoang tao khi hydro.
Trung tam dieu Idiien dat tren boong tau (ca nd) thuc hien cac chiic nang sau:
- Thu nhan va xii ly tin hieu tir dau dd tim de giup ra quyet dinh true vdt.
- Dieu khien ca can ghep ndi gan TBTV vdi vat can true vdt.
- Dieu khien md van cap nudc vao khoang tao khi hydro de gay phan iing.
- Dieu khien md van nap khi hydro vao phao chiia khi de tao lire nang.
Nguyen ly lam viec cua TBTV sir dung khi hydro
cd the dugc trinh bay ngan ggn nhu sau: :<ii;;
Budc 1: Nap hda chat vao khoang tao khi hydro.
De dam bao an toan, qua trinh nay dugc thirc hien trong tlii kin chira khi argon. Lieu lugng hda chat dugc tmh toan trudc phu thudc vao khdi luong, do sau cua vat can true vdt.
Budc 2: Dua TBTV xuong nudc bang can cau (hoac tdi).
Budc 3: Dd tim vat can true vdt thdng qua man hinh tren Tu dieu khien trung tam
Budc 4: Gan ca can ghep ndi (tay may thuy khi) So 10-Thang 10 nam2010
NGHIEN CUU - TRAO DOI vdi vat can true vdt thdng qua cac van thuy khi dugc
khdi ddng tir Tu dieu khien trung tam.
Budc 5: Md van cap nudc vao khoang tao khi hydro bang day dan khi cao ap dugc kich hoat tir Tu dieu khien trung tam.
Budc 6: Dua TBTV va vat can true vdt len boong (san) tau, len bd bing can cau (hoac tdi)
3. MOT SO DAC DIEM VE CONG NGHE CHE TAO KHOANG SINH K H I VA PHAO
C H T T A K H I
Trong qua trinh thiet ke, che tao TBTV, nhdm nghien ciiu gap rat nhieu van de ve cdng nghe, dac biet la thiet ke, che tao khoang sinh khi hydro, phao chiia khi hydro va cac van dieu khien. Cac ca cau nay phai dam bao cac yen cau sau day:
- Vat lieu phai cd do ben ca, ly, hda cao trong mdi trudng nudc.
- Ket can phai chac chan, ggn nhe (theo dang modul) de de van chuyen va thao tac
- Khoang sinh khi va phao chira khi hydro phai cd do kin khi tuyet doi.
- Cac CO cau van, khda phai cd do tin cay va chi sd an toan cao nhat bdi tiep xiic vdi chat tao khi hydro cd hoat tinh manh, de chay nd.
De giai quyet nhiing van de ndi tren, khi thiet ke, gia cdng khoang tao khi va phao chira khi, nhdm nghien Cliu da dac biet chii y tdi chi tiet sau day:
- Nap phao phai chac chan du do day chiu luc nen cua khi hydro dugc tao ra va phai tuyet ddi kin de khi hydro khdng thoat ra ngoai;
- Cac true dinh vi banh hda chat phai can bang, on dinh va tuyet doi song song vdi nhau, dudng ren phai thang va du sd lugng de giii chac chan cac banh hda chat.
- Vd phao chira khi hydro phai dugc han kin vdi nap ga tren, moi han dugc kiem tra bang sieu am va true giac bang dau hda bdi d nhiing vi tri xung yeu.
- Khoang chira khi va phao chiia khi phai cd cac gan trg luc xung quanh va d nap tren.
- Vat lieu lam vd khoang tao khi la thep cd do ben ca, ly, hda cao. Neu lam viec trong mdi trudng nudc nggt thi chgn thep tam C45 chiu 3,^=23 O^N/mm^, cd do day tir l,2H-2mm. Neu lam viec trong mdi trudng nudc man (nudc bien) chgn thep khdng gi.
Phao chiia khi
Khoang sinh khi
Co cau ghep noi
Hinh2
Nhdm nghien ciiu da chgn giai phap tdi uu la thiet ke khoang tao khi hydro cd 2 ldp: Ldp trong chiu ap suat cua nudc va chira hda chat sinh khi. Ldp ngoai cd dien tich Idn hon, chac hon cdn de lien ket vdi ca cau ghep ndi (tay may thuy khi). Sa do thiet ke ky thuat khoang va phao tao khi hydro dugc trinh bay d hinh 2.
De dam bao cac chi tieu ky thuat va yeu cau thir nghiem, nhdm nghien ciiu da dua ra phuong an thiet ke, che tao hai chi tiet rat quan trgng ciia TBTV cd nhung diem khac vdi phuong an cua ddi tac. Dd la van hut nudc vao khoang sinh khi va van xa khi tir khoang sinh khi vao phao chira khi. Day la hai ca cau phirc tap ddi hdi phai sir dung vat lieu cd do ben cao va dugc gia cdng vdi do chinh xac cao.
4. TINH TOAN, THIET KE HE THUY LlTC CUA C O CAU GHEP NOI
He thiiy lire la thanh phan chu yeu cua ca cau ghep ndi. Tren hinh 3 la so dd he thuy lire chuyen ddng tinh tien sir dimg pit tdng
cs^
Sd 10 - Thang 10 nam 2010
NGHIEN cuu-TRAODO!
A|^F, .\,
1 ^
Dudng kinh cua cau pit-tdng:rTTT ( 8 ) j = 2 / A ^ ^ 2
?^ffiTO^
r®"^
L U
^ V
Hinh3
6 day:
- Lire quan tinh: (1) F^ = m.a -Luc ma sat: (2)F^_. = m.gt
- Luc ma sat trong xi lanh Fg thudng bang 10% luc tong cdng, tiic la:
(3)F3 = 0,1F
- Luc tong cong tac dung len pit tong se la:
(4) F = — + F„, +F^+F^ \daN]
1000 >"' ' ' L J Trong dd:
Fj - lire di tai trgng ngoai gay ra (ngoai luc).
Do sut ap qua van se ty le vdi binh phuong he so dien tich R, tiic la:
(9)P„ = P,=(P^-P^),R2 Trong dd:
Pj, - ap suat dau cung cap cho van; • -' ^ Pj, P^ - ap suat d cac budng ciia xi lanh;
P^ - ap suat dau ra khdi van;
Aj, A, - dien tich hai phia ciia pit tdng.
Tir cdng thiic (5), (6) va (9) ta tim dugc Pj va P,:
P,.A,+R'(F + P,.A,) ., ( 1 0 ) i ^ = -
4(l + i?')
P.-P
0 -"iin)P,=Pr+ ^,
Tuong tu, khi pit tdng lam viec theo chieu ngugc lai thi:
( 1 2 ) P , = P ^ + (P„-P^)R2 _ PgA^R^ + F + Pj-A^R (13)^2
daN; A^(l + R')
daN;
m - khdi lugng vat nang, kg. s7cm;
a - gia tdc chuyen ddng, cm/s-;
F^^ - luc ma sat cua bd phan chuyen ddng.
Luu lugng dau vao xi lanh de pit tdng chuyen ddng vdi van tdc cire dai la:
(14) Q, = v .A, [cmVs],
^ ^ ^ I m a x max 1 •- J '
F^ - luc ma sat trong pit tdng - xi lanh, daN;
Ta cd phuong trinh can bang tinh ciia cac lire tac dung len pit - tdng.
P,A, = P A + F
Doi vdi xi - lanh khdng doi xiing thi luu lugng vao khac luu luong ra:
(6) Qj = Q,R, vdi ^ - ^ (he sd dien tich)
Tir dd, ta xac dinh dugc dudng kinh cua xi lanh (D), dudng kinh ciia cau pit-tdng (d). Cu the la:
- Dudng kinh ciia xi lanh:
(7)Z) = 2 . , / A V n
(15)Q,_ = ^ . 4 [ / / / ' / ^ ] ' '
Luu lugng dau ra khdi he thong khi lam viec vdi V la:
max
(16) Q, = v .AJcmVs]
^ '' ^ 2 m a x max 2 •- J
Luu lugng qua van tiet luu va van dao chieu dugc xac dinh theo cdng thiic Torricelli):
(18)g = ^ . ^ j ^ . V A P [cm'/s]
TAP CHf C a KHi VIET NAM V Sd 10-Thang 10 nam 2010
NGHIEN CUU - TRAO DOI
cm^];
Trong dd:
p - he sd luu lugng;
A^ - tiet dien mat cit cua khe hd [cm-];
AP = (Pj - P^) - ap suat trudc va sau khe hd [N/
S - Khoi lugng rieng cua dau [kg/cm^].
Luu lugng ciia bom: chgn bam dua vao P va Q =>
N deo dien
(19)Q, = n.VTi^. lOMvg/ph]
Trong dd:
n - Sd vdng quay [vg/ph];
V - The tich dau/vdng [cmVvg];
T]^ - hieu suat the tich [%].
Ap suat cua bom:
(20)P, =^^^^^.10[Ziar]
Cdng suat de truyen dgng bom:
(21) iV^ m, ,n-2
6^, -.10" [kW]
Trong dd:
M - md men tren true ddng co ndi vdi bam [Nm];
r|j^ - hieu suat co va thuy luc [%];
\ - hieu suat toan phan [%].
Cdng suat can thiet cua ddng ca dien la:
(22) N„ N
n,
[kW]
m/s;
Tinh va chgn dng dan (dng hiit, dng nen, dng xa):
Chgn van tdc chay qua dng:
- Ci ong hiit: v = 0,5 H- l,5m/s;
- d dng nen: P < 50 bar thi v = 4 -^ 5 m/s;
P = 50 + 100barthiv = 5-^6 P > 100 bar thi V = 6 - 7 m/s;
- 0 ong xa: v = 0,5 -^ l,5m/s.
Chgn kich thudc dudng dng:
Ta cd phuong trinh luu lugng chay qua ong dan:
(23)Q=Av Trong dd:
Tiet dien: (24) A •- nd'
Suy ra: (25) Q = ^—.v Trong dd: - d [mm]
- Q [lits/phiit];
- V [m/s].
Tit dd nit ra dugc:
(26)v = ^ : ^ . 1 0 ' 6.d^n
Bach thudc dudng kinh dng dan la:
(27)^ = 10.,
I2Q_
\mm\Nhiing ket qua tinh toan d tren cho phep thiet ke, che tao he thuy luc cua ca cau ghep ndi sir dimg pittong cd do ben ca hgc va do tin cay cao. Cac ket qua thu nghiem cho thay, cac thanh phan ca - dgng lire cua TBTV hoat dgng tin cay trong nhiing dieu kien sat vdi thirc te.
5. KET LUAN
TBTV sir dung khi hydro trong mdi trudng nudc la mdt he thdng gdm nhieu modul, trong do cd cac modul CO - ddng luc quan trgng la khoang sinh khi hydro, phao chira khi hydro va co cau ghep ndi. Nhdm de tai da xay dirng phuong an tdi uu va giai quyet nhiing van de cdng nghe phiic tap trong qua trinh thiet ke, che tao cac thanh phan ca - dgng luc de cimg vdi he thdng dieu khien ddng bg, TBTV dugc che tao da dam bao do an toan va hieu qua hoat ddng trong nhiing dieu kien sat vdi thuc tien.
Day la mgt trong nhiing san pham quan trgng nhat cua de tai KC05.21/06-10. San pham dang trong qua trinh thir nghiem, hoan thien va cd the dugc img dung phu hgp vdi dieu kien Viet Nam.
Tai lieu tham khao:
1. Oleg Kravchenko, Dmitri Cuzmin. Creation system ot the positive floatatibility on the basis of the hydrogen generation.
NationalAcad. Of science of Ucraitie.
2. "Sue ben vat lieu". Le Quang Muih, Nguyen Van Vupng.
NXB Dai hpc va THCN. Ha Npi 1989.
3. "Chi tiet may". Nguyin Trpng Hiep. NXB Dai hpc va THCN. Ha Npi 1970.
4. "Ky thuat thuy khi". Vu Duy Quang. NXB Dai hpc BK. Ha Noi 2000.
TAP CHi C a KHi VIET NAM V So 10-Thang 10 nam 2010
