HEAT TRANSFER ANALYSIS OF LNG TRANSFER LINE

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1 Scintific Jounal of Impact Facto(SJIF): 3.34 Intnational Jounal of Advanc Engining and sach Dvlopmnt Volum,Issu, Fbuay -05 HEAT TANSFE ANALYSIS OF LNG TANSFE LINE J.D. Jani -ISSN(O): p-issn(p): Mchanical Engining,.C. Tchnical Institut, Ahmdabad , Gujaat, India -mail Abstact: Ou objctiv of hat tansf analysis is to find out th amount of hat to b tansfd. In ou cyognic tansf lin ou ffot is to find out th ways to pvnt th hat to b tansfd fom high tmpatu to low tmpatu fluid. W us insulation to pvnt th hat tansf. Th chc of insulation fo a paticula application is usually a compomis in which factos such as conomy, convninc, wight, uggdnss, volum and oth poptis a considd along with th ffctivnss of insulation. Onc th insulation is slctd, hat tansf at is to b calculatd and optimiation of th insulation is to b don I. INTODUCTION On of th main chalgs duing th tim of tanspotation of LNG fom offsho to th stoag tminal and duing oth mans of tanspotation is to minimis th hat in-lak. In this pap w will calculat th hat in-lak o Hat tansf duing th tanspotation of LNG. II. POCEDUE FO HEAT IN-LEAK CALCULATION Hat tansf though tansf lin is a cas of hat tansf though composit cylind. Figu shows th hat tansf in composit cylind. Hat Tansf though Composit All ights svd 30

In ou cyognic tansf lin ou ffot is to find out th ways to pvnt th hat to b tansfd fom high tmpatu to low tmpatu fluid. W us insulation to pvnt th hat tansf.

2 Intnational Jounal of Advanc Engining and sach Dvlopmnt (IJAED) Volum,Issu, Fbuay -05, -ISSN: , pint-issn: LNG tansf lin is also a composit cylind systm mad of lays of diffnt matials as shown in figu. SOIL INSULATION OD JACKET(406.40) ID JACKET(387.40) LNG FILM T LNG OD INNE LINE(73.0) ID INNE LINE(64.70) Thmal sistancs of th LNG Tansf Lin = LNG = PIPE 3 = INSULATION 4 = JACKET 5 = SOIL Hat tansf though a cylind is givn by Wh, To Ti Q..(.) o π k L i To = Tmpatu of th out sufac T i = Tmpatu of th inn sufac K = Thmal conductivity of th cylind matial L = Lngth of th cylind o = Out adius of th cylind i = Inn adius of th cylind This is th hat tansf though a singl hollow cylind, but w hav many cylinds. So, h is th cas of hat tansf though composit cylinds. Th dnominato o in quation (.) psnts th sistanc to th hat tansf. π k L i Complicatd conductiv systm can oftn b tatd with analysis by intoducing th concpt of thmal All ights svd 3

70) Thmal sistancs of th LNG Tansf Lin = LNG = PIPE 3 = INSULATION 4 = JACKET 5 = SOIL Hat tansf though a cylind is givn by Wh, To Ti Q..(.

3 Intnational Jounal of Advanc Engining and sach Dvlopmnt (IJAED) Volum,Issu, Fbuay -05, -ISSN: , pint-issn: Hat Tansf though a Plan Wall o Slab Fo a wall o slab typ configuation, as shown in figu 6.3, thmal sistanc can b wittn as, Wh, A = aa of hat tansf L = gth of sction in th diction of hat flow K = thmal Conductivity Fo cylind, as shown in figu L.(.) ka o i (.3) π k L Total thmal sistanc to hat tansf of a composit cylind is givn by: In ou systm, H, n i i = = LNG + pip + insu + jackt + sl (.4) Th mthod of computing ach sistanc in a composit cylindical systm of LNG tansf lin is discussd in dtail in th following sctions. i. ES ISTANCE TO HEAT TANS FE BY All ights svd 3

3, thmal sistanc can b wittn as, Wh, A = aa of hat tansf L = gth of sction in th diction of hat flow K = thmal Conductivity Fo cylind, as shown in figu L.(.) ka o i (.

4 Wh, Intnational Jounal of Advanc Engining and sach Dvlopmnt (IJAED) Volum,Issu, Fbuay -05, -ISSN: , pint-issn: LNG..(.5) π d ip L h LNG h LNG = Convctiv hat tansf co-fficint of LNG. d ip = inn diamt of pip L = gth of pip ii. ES ISTANCE TO HEAT TANS FE BY INNE PIPE Pip lin is a cas of hollow cylind hat tansf, so sistanc of pip pip d op d ip π k pip L (.6) Wh, Kpip = Thmal conductivity of pip matial dip = inn diamt of pip L = gth of inn pip dop = out diamt of pip iii. ES ISTANCE TO HEAT TANS FE BY INS ULATION sistanc of insulation to hat tansf is also a hollow cylind cas, so sistanc, insu d ij dop (.7) π k insu L Wh, K insu = Thmal conductivity of Insulation dij = insid diamt of jackt L = gth of inn pip dop = out diamt of pip iv. ES ISTANCE TO HEAT TANS FE BY JACKET. Jackt is also lik a hollow cylind, so its sistanc to hat tansf is also givn by, jackt d oj d ij (.8) π k jackt All ights svd 33

6) Wh, Kpip = Thmal conductivity of pip matial dip = inn diamt of pip L = gth of inn pip dop = out diamt of pip iii.

5 Intnational Jounal of Advanc Engining and sach Dvlopmnt (IJAED) Volum,Issu, Fbuay -05, -ISSN: , pint-issn: Wh, K jackt = Thmal conductivity of jackt dij = insid diamt of jackt lin L = gth of inn lin doj = outsid diamt of jackt pip. v. ES ISTANCE TO HEAT TANS FE BY SOIL. Th sistanc to hat tansf by sl may b wittn as sl cosh ( ) (.9) π k sl L Wh, Ksl = Thmal conductivity of sl = out adius of insulatd pip Z = cnt lin dpth blow gound sufac Lt, cosh ( ) =.(.0) cosh 0 This is a quadatic quation in. So, a =, b = C = Solving this quation, th oots of th quation All ights svd 34

Th sistanc to hat tansf by sl may b wittn as sl cosh ( ) (.

6 Intnational Jounal of Advanc Engining and sach Dvlopmnt (IJAED) Volum,Issu, Fbuay -05, -ISSN: , All ights svd 35 () () 4 4 Taking +v oot only, (.) But, = ) ( cosh (Assumption-Equation.0) So ) ( cosh Putting valus of cosh in quation (6.7), W hav, sl sl L π k.(.) Fom quation (.4), Total sistanc to hat tansf, = LNG + pip + insu + jackt + sl But, sistanc to hat tansf by th inn lin sufac, th wall thicknss, and th jackt sufac a ngligibly small compad to th sistanc of th insulation and th sl. But, still w find th valu of ach sistanc to s th sult. Thfo, th total sistancs to hat tansf,

4), Total sistanc to hat tansf, = LNG + pip + insu + jackt + sl But, sistanc to hat tansf by th inn lin sufac, th wall thicknss, and th jackt sufac a

7 Intnational Jounal of Advanc Engining and sach Dvlopmnt (IJAED) Volum,Issu, Fbuay -05, -ISSN: , pint-issn: = insu + sl.. (.3) Putting valus of insu and sl fom abov quation, w hav, LNG Tansf lin buid und th Sl d ij dop π k insu L π k sl L (.4) Th LNG tansf lin is buid und th sl as shown in figu. Th sl tmpatu is about atmosphic tmpatu and piplin is at LNG tmpatu, so th hat chang btwn sl and th piplin taks plac as in th hat chang. Figu shows th tmpatu vaiation of LNG piplin and sl vsus gth o aa. Th tmpatu pofil can b considd th sam as in th condns with a snsibl loop. III. CONCLUS ION Hat tansf at of th nti LNG pip buid in sl systm is givn by, Q θm (.5) Σ It givs th amount of hat in-lak. To mov this hat, w hav to povid cooling station at gula intvals. Wh, T atm T (T atm Tc θ c ) m.(.6) T atm Tc T atm Tc Wh, Tc and Tc = Tmp. of nting and isting cold fluid and Tatm= Atm. Tmp. Th and Th = Tmp. of nting and isting hot All ights svd 36

Figu shows th tmpatu vaiation of LNG piplin and sl vsus gth o aa. Th tmpatu pofil can b considd th sam as in th condns with a snsibl loop. III.

8 Intnational Jounal of Advanc Engining and sach Dvlopmnt (IJAED) Volum,Issu, Fbuay -05, -ISSN: , pint-issn: ACKNOWLEDGEMENT Any accomplishmnt quis th ffot of many popl and this wok is no cptional. I thank my ps whos dilignt ffots mad this witing possibl. Many ampls, sts, sach wok, a th sult of a collction of many soucs, su ch as nws pap, jounal paps, and vaious wb sits ov th last 40 yas. Unfotunatly, soucs w not always notd o availabl, hnc it bcam impacticabl to povid an accuat acknowldgmnt. gadlss of th soucs, I wish to pss my gatitud to thos who may hav contibutd to this wok, vn though anonymously. EFEENCES [] Disstation pot ppad by th Autho. [] Hat and mass tansf by. K. ajput [3] andall F. Baon, Cyognic Systm [4] Flynn Cyognic pocss Engining [5]. S. Khumi and Gupta J.K; Machin Dsign [6] Coult, D. M., Dsign considation fo LNG pip lin, Advancs in cyognic ngining, All ights svd 37

Many ampls, sts, sach wok, a th sult of a collction of many soucs, su ch as nws pap, jounal paps, and vaious wb sits ov th last 40 yas.

Physics. Lesson Plan #9 Energy, Work and Simple Machines David V. Fansler Beddingfield High School

Physics. Lesson Plan #9 Energy, Work and Simple Machines David V. Fansler Beddingfield High School Physics Lsson Plan #9 Engy, Wok an Simpl Machins Davi V. Fansl Bingfil High School Engy an Wok Objctivs: Dscib th lationship btwn wok an ngy; Display an ability to calculat wok on by a foc; Intify th foc