TNH TON TIU TH NHIN LIU MY CHNH TU BINCALCULATION OF FUEL
COMSUMPTION FOR MAIN DIESEL ENGINESThS. NGUYN HNG VNG, TS. KHIU HU
TRIN, ThS. V NH PHIKhoa My tu bin, Trng HHHTm ttBi bo gii thiu mt s
phng php xc nh lng tiu hao nhin liu cho my chnh tu bin, t kt qu
nghin cu a ra mt bi ton ti u gip cc nh qun l tu c th tnh nh mc lng
tiu hao nhin liu ph hp vi thc t khai thc tu bin Vit nam.AbtractThis
article briefly introduces the methods for estimating fuel oil
consumption of main diesel engines. Based on the results of
research to establish optimum calculation method to estimate FO
consumption for ships that is applicable for Vietnam shipping
companies. t vn Khi gi c nhin liu trn th trng ngy cng cao th sc cnh
tranh trong vn ti bin cng khc lit. Chi ph nhin liu (NL) chim t trng
ln nht trong cc chi ph khai thc tu, thng vo khong 45 - 50%, thm ch
trn 50%. Do vy khng ch cc ch tu, cc nh my ng tu, m cc hng ch to ng
c ang tm mi bin php nhm gim chi ph nhin liu. Vic tnh ton nh mc hp l
tiu hao nhin liu ca tng con tu l ht sc quan trng.Vi khun kh bi bo
ny chng ti ch t ra vn tnh ton tiu th NL cho my chnh tu bin vi tnh
trng k thut hin ti, cc tuyn i c th. Mc ch l tm c cc h s hiu chnh ph
hp vi tng con tu c th theo tnh trng k thut ng c chnh, v tu v chn vt
trong cc iu kin khai thc - hnh hi thc t. T a ra kt qu tng i chnh xc
ph hp vi thc t trn tng con tu.Vi phng php tnh ton thng nht cho ton
b i tu trong cng ty, gip vic qun l chi ph NL s t hiu qu cao hn, nhm
hn ch cc hin tng tiu cc x hi, trnh c s tranh ci thng ny sinh gia nh
qun l vi cc s quan my trn tu khi bo co tiu th nhin liu. Phng php
tnh di y c kim nghim bng thc t trn mt s con tu. khng nh tnh kh thi
p dng cch tnh NL ny cho i tu ca mt s cng ty VTB Vit nam vi phng thc
tin hnh nh sau:nh gi tnh trng k thut thc t ca con tu v my chnh; (ch
yu l xc nh cng sut) Xem xt nh mc hin ti ca tng tu v tiu th nhin liu
theo kt qu th tu sau ng mi;Tnh ton li tiu th ca my chnh theo cng
thc xy dng da trn c s l thuyt; Xc nh tiu th NL thc t trn tu cho mt
chuyn i iu kin khai thc c th no ;Hiu chnh li cc h s cho ph hp vi
tng con tu v iu kin khai thc thc t;a ra nh mc tiu th ca my chnh tng
tu, ng vi cc iu kin ban u v vng quay my chnh, lng hng ho, cp sng
gi, tc tu.C s l thuyt tnh tiu th nhin liu my chnh tu binCng thc tnh
tiu th nhin liu cho ng c chnh lai chn vt tu bin c xy dng da trn c s
l thuyt nh trnh by sau y.- G24 - lng tiu hao NL ca my chnh, tn/ngy;
- no - vng quay nh mc ca my chnh, v/p;- Go - lng tiu hao NL my chnh
vi cng sut v vng quay nh mc; - n - vng quay ton ti ca my chnh ti
thi im tnh ton, v/p;- T - lng hng ch trn tu ti thi im tnh ton,tn;-
24 - s gi trong mt ngy.- To - trng ti ca tu, tn DWT;Cc yu t nh hng
nh kt cu ng c, tnh trng k thut, nh hng ca ti trng hng ho, tnh trng
k thut v tu, iu kin khai thc thc t c hiu chnh. Ci - l cc h s hiu
chnh do cc nh hng tc ng n tiu hao NL c th nh lng c nh sau: H s nh
hng ca tnh trng v tu v chn vtCng thc: C1 = Ykt - 1, trong : Kr l t
s tng tng sc cn R theo cng thc ca lU.A.Sved:l t s thay i hiu sut
chn vt theo thi gian khai thc v c tra theo th; Tkt - l thi gian tnh
t ln ln gn nht ca tu. H s tnh n nh hng ca cht lng nhin liu s dngXut
pht t cng thc tnh nhit tr NL:Qh
=(46,704-8,802.d2.10-6+3,167.d.103)(1-0,01(x+y+s))+0,0942.s
-0,02449.xCng thc xc nh h s Hoc c ththam kho Bng 1.Bng 1. H s nh
hng ca cht lng nhin liu.Thng s NLD (kg/m3)X (%)Y (%)S (%)Qh
(kcal/kg)Tiu chun9701,00,151,59800thc
t9801,50,22,5Qh(cI%+x%+y%+s%)=9634Qh thc
t9766975197959722C21,0031,0051,00051,0081,012.3. H s tnh n nh hng
ca iu kin kh hu mi trngCng thc:P,b : l p sut khng kh v p sut ring
phn ca hi nc iu kin thai thc thc t. T: nhit ca khng kh iu kin khai
thc thc t.H s tnh n nh hng ca tnh trng bin (iu kin sng gi)Cng thc
tnh :C4 = Ksg - 1Vi Ksg c tnh: : l c trng ca sng, tnh theo cng thc
thc nghim : :l cp sng.Ch s Frut biu th h s gi lc qun tnh v trng lc:
Tiu chun chu sng gi: Trong : FrL: H s Frut theo chiu di tu;V: Vn tc
tu, hl/h.g: Gia tc trng trng, m/s2;L: Chiu di thit k tu, m;T: Chiu
chm ca tu (mn nc ton ti), m; B: Chiu rng tu, m; : H s bo ca tu :
=D/L.T.B;D: Lng chim nc ca tu ton ti.3. p dng tnh th nghim thc t
trn tu binBng 2. Thng s c bn ca tu.Loi tuCh hng riChiu rng22 mNgy h
thu17/4/2001Chiu chm 100% hng8,365 mChiu di135/127 mLng chim
nc19.167,16 tnTrng lng tu khng3.664,82 tnDWT15.502,24 tnMy
chnhHanshin-Man-B&WKiu loi6S 35MC - 117Thng s nh mc4200 kW x
170 rpmS XL6ng knh xi lanh350 mmHnh trnh piston:1400 mmNhin liu th:
MDO, T trng (15oC): 0,8638 t/m3, Nhit tr: 42.460 kJ/kg, nht (50oC)
2,93 mm2/s kim nghim l thuyt v hiu chnh cc h s tnh ton trong cng
thc, thc nghim c tin hnh p dng tnh cho mt s tu bin Vit nam ang khai
thc tuyn ni a. Kt qu thu c cho mt tu c p dng tnh trn tuyn hnh trnh:
Qung Ninh - ng Nai, thc hin t 8/3/2010 n 10/3/2010.3.1 Thng s c bn
ca tu, my chnh v loi nhin liu s dngBng 3. Thng s nhin liu s dng.Cc
thng s c bnDOHFOCc thng s c bnDOHFO nht ng hc 50oC,
mm2/s3,173172,4Hm lng lu hunh0,152,56T trng 15oC,
t/m30,86980,9870Hm lng nc< 0,050,50Nhit tr thp,
kJ/kg45.30542,230Hm lng tro0,0020,049Hm lng than cn0,96.10-211,9Tp
cht trch lyN/A0,02Kt qu tnh tiu th nhin liuKt qu tnh ton nh mc nhin
liu theo cng thcSau khi kho st, nghin cu s liu thc t trn tu qua ghi
chp th tu sau ng mi, nht k bung li v nht k bung my, ghi chp tiu hao
nhin liu, nhn du, tnh trng x nc x cn my lc v.v... Nhm tc gi tin hnh
hiu chnh cc h s tnh ton thu c kt qu nh sau: Bng 4: Kt qu tnh ton
theo cng thcKt qu tnh theo s o thc t trn tuKhi o lng tiu th thc t
trn tu trong iu kin khai thc n nh, s liu c gim st cht ch, khoa hc.
Kt qu o thc t trn tu ngy 9 thng 3 nm 2010 ca tu th hin nh sau:Bng
5: S liu o ti kt FO settling tank.Ln c s liu1234567Mc thi
gian7h427h589h099h2210h3110h4611 h49Thi gian
(pht)16,0071,0013,0069,0015,0063,00Mc kt
(m)2,403,002,453,022,522,952,50Lng tiu th,
(m3)0,55000,50000,4500Tiu th V (m3/h)0,46480,43480,4286Tiu th
thgian bm0,12390,09420,1071Nhit kt (oC)989898T trng
(oC)0,98700,98700,9870H s hiu chnh0,90130,90130,9013B,
tn/ngy12,56912,69612,857Trung bnh(12,569 + 12,696 + 12,857): 3
=12,7073. Kt lunSau khi hiu chnh cc h s tnh ton, kt qu tnh ton l
thuyt v s liu tiu th thc t ch sai lch 53 kg/ 24h (khong 0,42%). Kt
qu cho thy mc chnh xc ca phng php tnh.Tuy nhin, nhm tc gi cng mong
mun c th nghim trn nhiu chng loi tu v trong nhiu iu kin khai thc
khc nhau. Ngoi ra nhm tc gii ang nghin cu xy dng tnh ton tiu th
nhin liu cho c h ng lc tu thu v tiu th nhin liu trong ch ma n iu ng
tu.TI LIU THAM KHO Iu. la Phomin, GS. Trn Hu Ngh. Xc nh cng sut
i--zen tu thu, Nh xut bn Giao thng Vn ti - H ni, 1990. TS. Lng Cng
Nh, ThS Trnh nh Bch. Khai thc i--zen tu thu. Nh xut bn Giao thng Vn
ti - H ni, 1998. TS. L Vit Lng, L thuyt ng c i--zen. Nh xut bn Gio
dc - H ni, 2000. PC Cuborob. Ch cng tc ca ng c chnh tu thu. Odecca,
2000. PhD Hachiri Kido. The basic of diesel plant performance
calculation. MTC Kobe, 2001. Instruction manual for Hanshin diesel
engine Man - B & W 6L35MCPhn bin: PGS. TS. L Vn Hc
