YWXY≸⓸G 䚐ạ⫼⫤㜈㫴⏼㛨⫵䚍䟀G ḩ┍䚍㍔䟀G ⊰ⱬ㬅
∢ᘛᬾݖ৯ԧᬾᕖئ⁾⋧ԧỾᘚᚦ⁆⯟ᩗỶئ⺂ڒ
Experimental study of internal flow field about 90degree elbow for cooling seawater pipe at
the main condenser
OH SEUNG JIN+, Cho DAE HWAN
1· BONG TAE GEUN
2· KIM OK SOK
3Abstract : While engine room arranging pipe which is used from the vessel, It measured the internal flow of 90 degree elbow which is used from the main condenser. Fluid flow in elbow of 90 degree is measured by PIV and Dewetron system. The Reynolds number adopts 50000 and experimental study of flow field in the elbow
Key words：Wall Thinning(감육), Flow Accelerated Corrosion(유동가속부식), Flow Visualization(유동가시화), 90degree elbow(직각엘보)
41# ⅉ#
㠮⽊㢖ٻṯ㦖ٻ䌚㏢ṫ㦒⪲ٻ㩲㧧♲ٻ⺆ὖ㣪㏢⓪ٻ㥶㼊ٻ䦦⯚ὒٻ㩧㽟䞶ٻἓ㤆㠦⓪ٻ㥶☯Ṗ㏣㔳ڃڡۇۊےٻڜھھۀۇۀۍڼۏۀڿٻڞۊۍۍۊێۄۊۉڄ㧊⧒⓪ٻ ㏦㌗㦚ٻ㞚ٻ⚦℮Ṗٻ㩦㹾ٻ㟝㞚㰖⓪ٻṦ㥷ڃڲڼۇۇٻگۃۄۉۉۄۉۂڄٻ䡚㌗㧊ٻ⋮䌖⋮ἶٻἆῃ㠦⓪ٻ㞫⩻ἓἚڃګۍۀێێېۍۀٻڝۊېۉڿڼۍ۔ڄ㧊ٻ䕢㡊♮ ⓪ٻ㌂ἶṖٻ㌳䞶ٻ㑮☚ٻ㧞┺ډٻ㧊⩂䞲ٻ㥶☯Ṗ㏣㔳㦖ٻἶ㡾㠦㍲ٻ▪㤇ٻ㕂䞮Ợٻ㌳䞮Ⳇٻ㧊ٻἓ㤆ٻ䌚㏢ṫ䚲Ⳋ㠦ٻ䡫㎇♮⓪ٻⰞ⁎⍺䌖㧊 䔎㦮ٻ㣿䟊㢖ٻⶒ㰞㩚╂㦮ٻ⚦ٻ┾Ἒ⪲ٻ㰚䟟♮Ợٻ♲┺ډٻἶ㡾㠦㍲㦮ٻ㥶☯Ṗ㏣㔳㠦ٻ╖䟊㍲⓪ٻڌڔړڋ⎚╖䎆ٻ㥶☯㔳㦚ٻ㧊⪶㩗㦒⪲ٻ㡞 䁷䞮₆ٻ㥚䞲ٻ㡆ῂṖٻ㰚䟟♮㠊ٻ┺㑮㦮ٻ㧊⪶ٻ㡞䁷ٻ⳾◎㧊ٻ㩲㔲♮㠞┺ډٻ⁎ٻ㭧㠦㍲☚ٻڞۃۀۓڼۇڈڣۊۍۄےۄۏەٻ⳾◎ڌڄὒٻڦڼێۏۉۀۍڈڭۄۀڿۇۀٻ⳾ ◎ڍڄ㦖ٻ䆪✲⪲ٻṲ♮㠊ٻ㔺㩲ٻ䡚㧻㠦ٻ㩗㣿♮ἶٻ㧞㦒Ⳇڇٻ䡚㨂₢㰖ٻ䚲♲ٻ㥶☯Ṗ㏣㔳ٻ㡞䁷ٻ⳾◎㦖ٻ╖ٻ㥶㼊ٻ㭧㦮ٻ㞫⩻⼖䢪ڇٻ 㥶㏣ڇٻ㻶㧊㡾ٻ⏣☚㹾ڇٻ㏣ڇٻ㻶䡫䌲ٻ❇㠦ٻ➆⧒ٻ㥚䂮㠦ٻ➆⧒ٻṦ㥷⮶㦚ٻἚ㌆䞶ٻ㑮ٻ㧞☚⪳ٻ㩲㔲♮㠞┺ډٻ⁎⩂⋮ٻ㔺㩲ٻ䡚㧻㠦㍲⓪ٻ╖ ٻῃ㩗㦒⪲ٻṦ㥷㧊ٻ㌳䞮ἶٻ㧊⩂䞲ٻ䡚㌗㧊ٻ▪㤇ٻ㰚䟟♶ٻἓ㤆ٻῃ㏢㩗㦒⪲ٻ䕢Ὃ㧊ٻ㌳ڇٻ㍺ٻٻ䕢㡊㧊ٻ㌳䞮Ợٻ♲┺ډٻ㍶㦮ٻ 㭒⽋㑮₆ٻ䟊㑮⌟ṗ⺆ὖ㦮ٻἓ㤆ٻ㡾☚⓪ٻڎڋଇ㩚䤚⪲ٻ⏨㰖ٻ㞠㦒⋮ٻザ⯎ٻ㥶㏣㧊ٻṦ㥷ٻ䡚㌗㦮ٻ⚦✲⩂㰖Ợٻ⋮䌖⋮⸖⪲ٻ㡞㩫゚ٻ㹾㤦㠦 ㍲ٻ㭒₆㩗㦒⪲ٻᾦ䢮ٻ㧧㠛㦚ٻ㑮䟟䟊㟒ٻ䞮⋮ٻ㧊㠦ٻὖ䞲ٻ㡆ῂ⓪ٻⰤ㰖ٻ㞠㦖ٻ㔺㩫㧊┺ډٻ㧊ٻ㡆ῂ㠦㍲⓪ٻ㔺㩲ٻ⺆ὖṲ㏢ٻ⌊㠦㍲ٻ㏣☚㎇ 㠦ٻ➆⯎ٻῃṦ㥷ٻ䡚㌗㦮ٻ㌳㠦ٻ╖䞲ٻ㰗㩧㩗㧎ٻ㍳㦚ٻ㥚䟊ٻ㞫⩻Ἒ䁷ٻٻ㥶☯ٻṖ㔲䢪ٻ㔺䠮㦮ٻἆὒ㡗㌗㦚ٻګڤڱ₆⻫㦚ٻ㩗㣿䞮㡂ٻ 㩚㥶☯㧻㦮ٻ㏣☚⯒ٻἚ䁷䞮㡂ٻἶ㡾㧊ٻ㞚┢ٻἓ㤆㠦ٻ㧞㠊㍲ٻ㥶☯㠦ٻ➆⯎ٻ㏣☚㎇ὒٻῃṦ㥷ڃڧۊھڼۇٻڲڼۇۇٻگۃۄۉۉۄۉۂڄٻ㌗ὖὖἚ⯒ٻἶ 㺆䞮ἶ㧦ٻ䞮㡖┺ډ51# ⍈# 㢖
㔺䠮㦖ٻڔڋ☚ٻ㰗ṗٻ㠮⽊ٻ䡫㌗㦮ٻ䕢㧊䝚ٻ⺆ὖ㦚ٻ╖㌗㦒⪲ٻ⌊ٻ㥶☯㧻㦚ٻ䒂ⳛ䞲ٻ㞚䋂Ⰺ⪲ٻ㩲㧧䞮ἶٻ㧛㧦⯒ٻ‶㧒䞮Ợٻ䙂㔲䅲ٻ㥶 ☯㧻㦚ٻ䡫㎇䞮㡖㦒Ⳇٻڍ㹾㤦ٻ⩞㧊㩖ٻ㔲䔎ὧ㤦㦚ٻṖ㔲䢪⯒ٻ㤦䞮⓪ٻ┾Ⳋ㠦ٻ㫆㌂䞮㡂ٻ㡗㌗㦚ٻ㾂㡗䞮㡖ἶڇٻګڤڱἚ䁷㦮ٻ㌗㣿㏢䝚䔎㤾㠊ڇٻ ڞڜڞگڰڮڍڋڋڋ㦚ٻ㌂㣿䞮㡂ٻ㏣☚㧻㦚ٻῂ䞮㡖┺ډٻ㔺䠮ٻ㧻䂮⓪ٻ⺆ὖٻ㔲㓺䎲ὒٻ䗢䝚ڇٻⶒ䍇䋂ٻ⁎Ⰲἶٻ㞫⩻ٻ䁷㩫㦚ٻ㥚䞲ٻ㞫⩻Ἒ䁷ٻ㎎䔎⪲ٻ ῂ㎇䞮㡖┺ڃ⁎Ⱂٻڌٻٻ⁎Ⱂٻڍٻ㺎㫆ڄډٻ⺆ὖٻ㔲㓺䎲㦖ٻ㠮⽊㢖ٻ䕆ڃگۀۀڄٻٻ㡺Ⰲ䞒㓺ٻ䤚┾㠦ٻ╖䞲ٻ㔺䠮㦚ٻ䞶ٻ㑮ٻ㧞☚⪳ٻῂ㎇♮㠞㦒 Ⳇڇٻ㔺䠮ٻ㥚㦮ٻ㩚ڇٻ䤚┾㠦⓪ٻ㥶☯㦚ٻὖ㺆䞶ٻ㑮ٻ㧞☚⪳ٻ䒂ⳛٻ㞚䋂Ⰺٻ䕢㧊䝚⯒ٻ㌂㣿䞮㡂ٻṖ㔲䢪ṖٻṖ⓻䞮☚⪳ٻ䞮㡖┺ډٻ㔺䠮ٻ㧻䂮ٻ ⺆ὖ㦒⪲⓪ٻ⌊㰗ἓٻڐڋٻھۈ㦮ٻ㓺䎢㧎Ⰲ㓺ٻ⺆ὖ㦒⪲ٻ㍺Ἒ䞮㡖㦒Ⳇٻ♮Ⳇٻ㠮⽊⓪ٻ㔺㩲ٻ䡫㌗㦚ٻ⳾◎Ⱇ䞮㡂ٻ⼚☚ٻ㩲㧧䞮㡖┺ډٻ ٻٻٻٻٻٻ ٻٻٻٻٻٻٻٻٻFig. 1 Visualization Pipe Section Fig. 2 Piping System
ٻٻچٻ㡺㔏㰚ڃ⳿䙂䟊㟧╖䞯ᾦٻ╖䞯㤦ڄڇڠڈۈڼۄۇڕۋۇېێڌړڐڋڛۈۈېډڼھډۆۍڇٻگۀۇڕٻڋڑڌڄڍڏڋڈڒڍڌڒ ٻٻڌٻ⳿䙂䟊㟧╖䞯ᾦٻٻ䟊㌂╖䞯ٻ₆ὖ㔲㓺䎲Ὃ䞯
ٻٻڍٻ⳿䙂䟊㟧╖䞯ᾦٻ䟊㟧Ὃὒ╖䞯ٻ㫆㍶䟊㟧Ὃ䞯ὒ
(a) straight pipe
ٻٻٻٻ
(b) 90° elbow Fig. 3 Definition of geometries of wall thinning defect
㥶☯Ṗ㔲䢪㢖ٻ㔺䠮㦚ٻ䐋䟊ٻ䁷㩫䞲ٻ㞫⩻䙂⯒ٻ㧊㣿䞮㡂ٻῃٻṦ㥷㦮ٻὒ㩫㦚ٻỖ䏶䞮㡖┺ډٻ㞫⩻ٻ䁷㩫㦖ٻṗٻ䙂㧎䔎ٻ⼚⪲ٻڌڋ䣢㝿ٻ䁷 㩫䞮㡂ٻ䘟‶Ṩ㦚ٻ㌂㣿䞮㡖┺ډٻ㔺䠮㠦ٻ㩗㣿♲ٻ㥶㏣㦖ٻڞڼێۀٻڌ㠦㍲⓪ٻ㭒㧛ῂٻ䟻㦒⪲ٻڋډڍٻۈڊێ㧊ἶڇٻڞڼێۀٻڍ㠦㍲ٻ㭒㧛ῂٻ㟧㴓㦒⪲ٻ ڋډڏٻۈڊێ⪲ٻ☯㧒䞲ٻ㥶㏣㧊ٻ㩗㣿♮㠞ἶڇٻڞڼێۀٻڎ㦮ٻ㥶㏣㦖ٻڋډڑٻۈڊێ㧊┺ډ
61# ੑ# ᮙ# ઉⶺ
㥶☯Ṗ㏣㔳㠦ٻ㦮䞲ٻ㭒⽋㑮₆ٻ⌟ṗٻ⺆ὖ㈦Ⱒٻ㞚┞⧒ٻ㍶㦮ٻ㡂⩂ٻ㥚㠦ٻ䕢Ὃ㦚ٻ㽞⧮䞮㡂ٻ㏦㔺㦚ٻ㽞⧮䞶ٻ㑮ٻ㧞㦒⸖⪲ٻ㻶㩖䞲ٻ ὖⰂṖٻ䞚㣪䞮┺ډٻ䡚㨂₢㰖ٻṲ♲ٻ㥶☯Ṗ㏣㔳ٻ㡞䁷ٻ⳾◎✺㦖ٻ₆ٻ㍺㩫♲ٻἶ㡾㦮ٻ㌗䢿㧒ٻἓ㤆ٻ⺆ὖṲ㏢㠦ٻ╖䞲ٻṦ㥷ٻ㥾㦚ٻ㡞䁷䞶ٻ 㑮ٻ㧞┺ډٻ䞮㰖Ⱒٻ㍶㦮ٻἓ㤆ٻ㥶☯Ṗ㏣㔳㦖ٻῃ㩗㦒⪲ٻ㌳䞮ἶڇٻ₆㫊㦮ٻ⳾◎⪲⓪ٻ㧊⯒ٻ㡞䁷䞮₆ٻ㠊⪋┺ډٻ➆⧒㍲ٻ㧊ٻ㡆ῂ㠦㍲ ⓪ٻ⺆ὖṲ㏢㠦㍲㦮ٻῃṦ㥷ٻ䡚㌗㦚ٻ䕢㞛䞲ٻἆὒٻṦ㥷㦖ٻ㏣☚㠦ٻ㰖⺆㩗㧊⧒⓪ٻộ㦚ٻ㞢ٻ㑮ٻ㧞㠞┺ډٻ⡦䞲ڇٻ⌊㥶☯㧊ٻ⼓Ⳋ㠦ٻ➀ 䧞Ệ⋮ٻ⚦ٻ㥶☯㧊ٻ㿿☢䞮Ⳋ㍲ٻ㌳䞮⓪ٻڍ㹾㥶☯㧎ڇٻ䣢㩚㥶☯㠦ٻ㦮䟊ٻ㿲ῂ㠦㍲⓪ٻṦ㥷㧊ٻ䞲㴓㦒⪲ٻ䂮㤆㼦ٻ㌳䞮㡖┺ډٻ⁎Ⱂٻڏ ⓪ٻ㠮⽊⯒ٻ㰖⋮⓪ٻ䦦⯚㧊ٻ㠮⽊ṗ☚ٻ㯳Ṗ㠦ٻ➆⯎ٻṗٻ┾Ⳋ㦮ٻ㑮䘟䟻㏣☚㎇ٻٻ㑮㰗䟻㏣☚㎇ٻ⁎Ⰲἶٻ⋲⮮㤊☯㠦⍞㰖㦮ٻ䙂 ⯒ٻ⋮䌖⌎ٻộ㧊┺ډٻڔڋ☚ٻ㠮⽊㦮ٻ䡫㌗ὒٻ㥶☯㦮ٻ㤦㕂⩻ٻ❇ٻ㩲ٻ㣪㏢㦮ٻ㡗䟻㦒⪲ٻ㑮㰗䟻㏣☚⓪ٻ㯳Ṗ䞮⓪ٻἓ䟻㦚ٻ⽊㧊ἶٻ㧞㦒Ⳇٻ 䔏䧞ٻ㤆䁷⼓Ⳋ㠦㍲㦮ٻ㯳Ṗ㥾㧊ٻ⏨Ợٻ⋮䌖⋮ἶٻ㧞┺ډٻ⁎⩂⋮ٻ⋲⮮㤊☯㠦⍞㰖㦮ٻἓ㤆ٻ㡺䧞⩺ٻ⼓Ⳋ⁒㻮㠦㍲ٻṦ㏢䞮ἶٻ㧞㦒Ⳇٻ㩚㼊㩗 㧎ٻ㥶䐋ٻ䡫䌲⓪ٻ㧒ὖ㎇㦚ٻ㥶㰖䞮ἶٻ㧞㦢㦚ٻ㞢ٻ㑮ٻ㧞┺ډ X V el o c it y , Y V el o c it y T u rb u len t K in et ic E n er g y (k ) -0.4 -0.2 0.0 0.2 0.4 0.05 0.10 0.15 0.20 0.25 0.5 1.0 1.5 2.0 2.5 X Velocity Y Velocity Turbulent Kinetic Energy (k)X V el o c it y , Y V el o c it y T u rb u len t K in et ic E n er g y (k ) -0.4 -0.2 0.0 0.2 0.4 0.05 0.10 0.15 0.20 0.25 0.5 1.0 1.5 2.0 2.5 X Velocity Y Velocity Turbulent Kinetic Energy (k)
X V el o c it y , Y V el o c it y T u rb u len t K in et ic E n er g y (k ) -0.4 -0.2 0.0 0.2 0.4 0.05 0.10 0.15 0.20 0.25 0.5 1.0 1.5 2.0 2.5 X Velocity Y Velocity Turbulent Kinetic Energy (k)
Fig. 4 variation of each velocity component and turbulent kinetic energy
