NGHIEN CU'U-TRAO DOl
ANH H l f d N G CUA CHI^U SAU CAT VA T 6 C D O QUAY DEN MO MEN DAN DONG VA NANG LUONG RltNG CLIA
DAU
C A THUT SAN HO
INFLUENCE OF CUTTING DEPTH AND ROTATIONAL SPEED ON THE DRIVING TORQUE AND SPECIFIC ENERGY OF CUTTER SUCTION
DREDGER HEAD
TS. Tran Hiru Ly Hpc vien Ky thudt Qudn su
TOM TAT
Thiit bi cdt hut m& luong da duac sir dung rgng rdi ti'in the gi&i. O Viet Nam, Tong cong ty Xdy dtmg Ldng Lo da nhgp thiit bi cdt hut tir ndm 2015. Tuy nhien, chua co tinh todn ndo cua thiit bi khi thi cong a biin ddo nuac ta nen khd ndng triin khai cong viic cdn hgn che. Bdi bdo trinh bdy phuangphdp phdn tich tuang tdc giira ddu cdt vd dd san ho, tir do xdc dinh luc cdn cdt, tinh todn mo men cdn cdt trin true ddn dgng vd ndng luang cdt rieng, khdo sdt dnh hu&ng cua chiiu sdu cdt vd tdc do quay cua ddu cdt den mo men cdn cdt vd chi phi ndng lugng rieng trong qud trinh ngo vet nen san ho bdng thiit bi cdt hut chuyin dung. Tu do, co chi do ldm viic phii hcrp cua ddu cdt vai moi logi san ho.
Tix khda: Ddu cdt dd; Dd san ho; Chieu sdu cdt. Toe do quay ddu cdt.
ABSTRACT
Cutter suction dredger equipment has been widely used around the world. In Vietnam, Lung Lo Construction Corporation has imported cutter suction dredger equipment since 2015. However, there is not a calculation of equipment when constructed in the sea of our country yet, therefore the ability to apply in this situation is limited. This article presents the interaction analysis method between the cutting head and the coral to determine the cuttingforce, the cutting torque on the drive shaft and the specific cutting power Investigating the influence of cutting depth and the rotational speed ofthe cutting head to the cutting torque and the specific energy costs during the coral dredging process by a special suction cutter From there a suitable working mode ofthe cutter with each type of coral is determined
Keywords: Cutter suction dredger, coral, cutting depth, rotational speed.
ISSN 0866 - 7056
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NGHIEN CLTU - TRAO D 6 |
1. D^T VAN DE
Phuong phap md ludng chii yeu cua chiing ta hien nay vdn la su dung vat lieu nd vi CO uu diem Id md ludng nhanh, nhung nhupc diem la de gay ra mat an toan cho ngudi, dnh hudng tdi mdi sinh va dia chdt cua khu vuc.
Ngoai ra, viec su dung vat lieu nd hien nay rat nhay cdm khi ttanh chap tai khu vuc qudn ddo Trudng Sa dang gia tang. Sir dung thidt bi cat hiit chuyen dung la phuong phdp md ludng khdng nd. Thidt bi nay vira cdt pha dd vua hiit va chuyen san phdm di nai khac mdt cdch nhanh chdng va khdng dnh hudng tdi cdu tnic dia chdt cung nhu mdi sinh (hinh 1).
Da cd nhieu cdng trinh khoa hpc nghien cim ve tuong tdc giiia rang cdt vd nen ddt nhu N.G Dombroski, A.N Zelenhin, Ju.A.
Vetto...[l], phuang phap tinh toan nay da dupc su dung rdng rai de tinh toan luc can cat dat ttong qua trinh tinh toan va thidt ke may thi cdng ddt. Tuy nhien, nhiing cdng thiic nay chua phan anh ddy du ban chat ciia tuong tac mdi ttudng den thiet bi cat hiit. Cdc tdc gid [2], [3] da dua ra md hinh tinh todn ly thuyet de tinh toan luc can cat, mdmen va nang luong cat rieng cua ddu cat thi cdng dudi nudc. Bai bdo nay ke thira phuong phap tinh toan d tren de tmh toan anh hudng cua chieu sdu cat vd tdc dp quay cua dau cat den md men cdn cat va chi phi nang lupng rieng khi thi cdng md ludng tai cac ddo Viet Nam.
2. TUDONG TAC G I C A DAU CAT VOfI NEN
2.1. Tinh toan luc can va md men ddn dgng Hien, cd hai phuong phdp cdt pha duac sir dung khi ddu cat lam viec dudi nudc phu thudc vdo hudng cita ludi cat vd chieu quay cua dau cdt. Phuang phdp 1: Cdt tii tren xudng va phuong phdp 2: Cdt tir dudi len, so dd tinh toan luc cat dupc the hien ttong hinh (2).
Hinh 2 Sa do linh lodn lire cdn cdt Theo [21, tdng luc can trung binh dupc tinh bang tdng cac luc can thanh phan tdc dung len ddu cdt bang cdng thiic:
Ho
JF^dQ (1)
Hinh 1. Ddu cdt phd ma luong
2;r ^ Trong dd:
p- Sd lupng rang cdt, [chiec];
F^- Tdng luc cdn trung binh, [N], Q. - Gdc d tdm phan cung dau cat cat ddt, [rad].
Hp- Gdc d tam ldn nhdt, [rad].
Luc va md men theo cdc phuang duac xac dinh nhu sau:
+ Tdng luc cdn theo phuang s.
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NGHIEN CU'U - TRAO B6\
g, I sin- HcosfidQ + g, J" sin^ H d n [+] Tdng lire can theo phuang dimg v:
g, [ sm^ QdQ - g ; I sin^ Q c o s a d Q
gj J sinncosQdQ ±g^ f sin^ QdQ
Ho no
±g3 j sin^ QdQ ~ g, J sin^ OdQ
+ Tdng luc can theo phuong dpc true a:
Fa. = CgcBs j sin^ Q d Q + c^^g^ j sin Q6D.
0 n, + Md men dan ddng:
IVI, = Cg^g,R j sin^ n a n + c^^gjR I sin O d Q 0 n,
Cdc he sd cgc va cca cd don vi la (kN), chiing dupc xac dinh bdng cdng thiic sau:
(2)
(3)
(4)
(5)
•Pwg-bpr-^.,R-hfa
•Pw-g-tpr-(Z + 1 0 ) h , „ g^ ^-dj.tant.sin^ + dj. COSi^
cost '
g, =C,.COSt.COSi^
g j =-C|.sinLsini^.cos^-i-C2.cos^i^ g^ =dj.tant.coS(^-l-d,
gj ^ C j . s i n t . c o s ^ ^ + C j . s i n ^ . c o s ^ ; s i n ^ c o s t ' Trong dd:
t - Gdc nghieng ciia rang cat theo phuang dpc true ddu cat [rad];
R- Ban kinh dau cat, [m];
Vg- Van tdc chuyen ddng cua dau cat theo phuong s, [m/s];
n- Tdc dp vdng quay ciia ddu cat, [rpm];
b^- Chieu rdng vet cat cua rang cat theo phuang dpc true dau cat, [m];
t,- Gdc ndn ciia dau cat, [rad];
t- Gdc nghieng cua rdng cdt theo phuang dpc true ddu cat, [rad];
V^- Van tdc dai cua rang cat, [m/s];
h^- Chieu ddy phoi cat ldn nhdt, [m].
h,- Chieu day phoi cat, [m].
Q.^- Gdc xdy ra qud trinh xdm thuc, [rad];
CpCj- He sd luc cat khdng thii nguyen;
d,;dj- He so lire cdt khdng thir nguyen.
ISSN 0 8 6 6 - 7056
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NGHIEN C L f U - T R A O D 6 |
2.2. Nang lirong cSt rieng cua d^u cat
Nang luang cat rieng duac tinh toan dua tren mo men din dong trung hinh luc dSn tien tnmg binh va Iuc cat pha trung binh. Nang Iugng rieng cit rieng dugc tinh theo cong thiic;
M,ft) + F,v, M,cu
Av, v , b . R ( l - c o s n „ ) Tir phucmg trinh (9), (12) va (13) ta co:
2c,egRv, cos i cos ^ E =
Pk„
l - c o s f 2 , ) + di(z + 1 0 ) ( n „ - n , )(13)
(14)
3. ANH HlTdNG CtJA CUA CHIEU SAU VA TOC DO QUAY DAU CAT Tdl MO MEN DAN DQNG VA NANG LU'ONG CAT RifiNG
De thuan lgi cho qua trinh khao sat, nhom tac gia su dung dir lieu nghien cuu vg nen san ho tir tai lieu [6] va [2].
c, 0.291
a 30"
<=,
0.202
|3 33.636°
d, 2.303
<P 37"
1.
1.424 6 21°
P,i 1000
n 80
g 9 81
P 10
V
0.2 b 0.2
I
30"
z 0.6
^
30"
R 0.5 Cac thdng sd ldm viec cdn khdo sdt
gdm cd: Chieu sdu cat Bv, tdc dp quay cua dau cat n, van tdc ddn tien ddu cdt v^. Sii dung phan mem Mathlap tinh toan theo cdng thiic (9), ta thu dupc cac gia tri can thiet.
3.1. Anh htr^g ciJa chieu sau cdt B^
Khi tang chieu sau cat thi luc can cdt tang len, md men ddn dpng va ndng lupng rieng trong trudfng hpp nay tang gan nhu tuyen tinh theo chidu sdu cat (hinh 5).
Hinh 3. Anh hu&ng chiiu sdu cdl den momen ddn dong vd ndng lugng neng ^ ISSN 0866 - 7056
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NGHIEN ciiu-TRAO DOI
3.2. Anh huffng cua tdc dp vong quay dau cat n
Ngay nhdn bai: 10/5/2017 Ngay phdn bien: 15/6/2017 Gid tri md men ddn ddng ddu cdt trong
trudng hpp nay se giam tuang ty nhu sy giam cua luc can cat cdn nang lupng rieng cua dau cat trong trudng hpp nay gan nhu khdng ddi (hmh 7).
Tai Iidu tham khao:
[1]. P. Dong, L. Thuan, H. Ngii; Mdy ldm ddt, 2004.
[2]- S. Miedema, "The Cutting Forces in Saturated Sand ofa Seagoing Cutter Suction Dredger," Processding WODCON XII, Orlando, Florida USA, April 1989, 1989.
[3]. I. Kovacs, M.-S. Nan, and I. Andras, "Study of the interaction of ike cutting heads of the rock culling machines with rocks,"
University of Miskolc Series A. Mining, vol.
65, no. A, pp. 73-93,2004.
[6]. H. X. Lupng; Nghien ciru cdc chi tieu ky thudt cua nen san ho vd tuang tdc giira kit cdu cdng trinh vd nen san hd, 2010. Bao cao tdng hpp kSt qua dg tai KC.09.07/06-10.
Hinh 4. Anh hu&ng cua toe do ddu cdl den dp sudt ddu mo la quay ddu
4. KET LUAN
Bdi bdo trinh bay phuang phap xac dinh lyc can cdt, md men dan ddng vd nang lupng rieng cua dau cat pha da san hd thi cdng dudi nudc. Ddng thdi, khao sat dnh hudng cua cdc thdng sd lam viec cua dau cat den cac gia tri nay. •
ISSN 0866 - 7056
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