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EDITORIAL JurnalMesi[ datrIdustri (JMI), Volume7, Nomor l, Edisi Ianuari 2010,merupakanJMI terbitan Pertamauntuk tahun2010.Padaedisi ini JMI menyajikaulima buahMskah terpilih terdiri atasI buah makalahkeloopok Bidalg Telxik Industri dao4 buah makalahkelompok Bidang Teknik Mesin yang merupakanhasil pe4elitiatrmaupunkajian kdtis. semoga JMI dapat menjadi wadah yaag terpilih bagi para staf akademil, mahasiswapasca sadaM maupuEparapeneliti dari lembagariset unhk dapatberbagipengetahusndemi kemajuaailnu pengetahuandan teknologi Indonesia. Akhimya tim peryunting me[gucapkadterima kasih atas partisipasinyadalam edisi kali ini. Semogaapayang telah dilahrkan id dapatmemberikaflmanfaatbagi kita semua.
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DAFTARISI Editorial DaftarIsi BidangTeknikIndustri 1. DESAIN ULANG ALAT POTONGTULANG SAPI SEBAGAIBAHAN BAKU HIDROKSIAPATITDENGANMEMPERTIMBANGKANASPEKERCONOMI AaiadyaHaoumMurti dar Alva EdyTontowi
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Bidary TeknikMesin 2. PENGARUHLAPISANIMPLANTASIION NITROGEN(N2) TERHADAP KEKERASANDAN LAJUKOROSIBAJATATIANKARAT304 -=. \4ktor MalaudaoKusmono 3. i EXPERIMENTALSTUDYON THE HYSTERESISEFFECTDURINGTHE COIJNTBR-CURRENT AIR-WATERTWO-PHASEILOW IN A HOT LEG PRESSURMDWATERREACTOR Deendarlianto daDSubanaD.................. .............
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4. PENGARTJH LAru PEMAKANAN TERHADAPKEKASAI{AN PERMUKAAN MAIER]AL BEARING STEELPADA PROSESPEMOTONGANDENGAN MESIN BUBTJ"T EMCO MA)CMAT V13 Subarmonodan E&at BambangAdinugroho
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5. USAHA MENINGKATKAN KEKERASAN DAN KETAHANAN KOROSI BAJAAISI 4140DENGAN TEKNIK IMPLANTASI TIIANTTJMNITRIDA TN viktor Malau dadMuhammad
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EXPERIMENTALSTUDYON THE IIYSTERESISEFFECT DTJRINGTHE COIJNTER-CI]RRENT AIR-WATERTWO-PHASEFLOW IN A EOT LEG PRESSIJRIZEDWATERREACTOR D€enderlianto and suhanrn DepartroedofMechanical andlndustrial Engineering,Faculty of hgineeriDg GadjahMadaUnivenity Jl. Grafka No.2, Yogyakarta5528r E-mail
[email protected],
[email protected]
ABSTRACT air-water two-Pha5e An investigationob hystercsisefrectduring the coufttet'-curTent frow in a hot leg pressurizedwater rcactor has beenconductedeq)ei entally. Thepattem of tdt sectionwaa rectangularcrosssection,inwhich it is a sihplifcation ofKonvoi nuclearreactor.me rectangularchonnel dimension,the letlgth of the hoizontal part and the inclination angle of the riser were (0.25x0.05)m', 2.12h, and 50"from horizontalplane, rcspectively.Theonsetoffooditrg and defooding, wasobserved bJ analyzingthe data ofwater letelsfiom a vesselsimulatihg stedrfigeflerator,reactorprdsure vessel and visual obsenation. The onsetoffooding is def ed as the maximumair massfow rate at which the drschatEedv)atermossfow rate is eqlal to the inlet water massflow rate-Meanwhile the onsetof defioodingis defnedas themdximu airmassfo\rrate, atwhichthe down-flnuingwaterfiaasfrorerate beginsto be equalto the ihje.ted water massflow tate. As a resuh,it wasfound that (1) theocc ftence ofswflow and thestartingincteaseof thepressuredrop are integralphebotne a ofthe initial stageof tllefroodfug dunng the coufiter-cutentjow of air-water br a hot leg pressurizedilater reactor,(2) an hysteresisefect appearson the onsetoffrooding, and (3) the hystelesisefect becomesthoreinq)orta t whenincreasingthe watel massfo'| rate, Keryorils: Two-pha$e fow, countet-cunentfrow fooding, defrooding,pressurized.water rcactor 1. INTRODUCTION TheoDsetofflooding, in a hotizontalchannel contrectedto arr inclircd riser has received a specialattentionfor safetyrcgulahor in thetruclear industry. This geometryis analogousto that of a hot leg connectingthe reacto! pressluevessel (R?9 with the steamgeneratorin a pressurized water reactor (PWR). One hypothetical scenano is a flooding phenomenonduring the event of a loss-of-coo1a-accident(LOCA) h PWR, which is causedby dahageat anypositionof theprimary circuit. During this conditionit is consideredthat andvaporization the rcactorwill be depressurlzed, takes place, Furrhermore.satwated sleam is generatedin the reactor corc, and rushesout of
horizontaland inclinedpipesof rbe bot leg. Tte steamwill condensein the steamgeDeratotadd flow back to the reactor corc (reflux condenser mode). Consequedtlya stladfied counter-current flow of steam and condensateoccurs in those pipes. The stradfiedcou er-currentflow of steam andcondensate is oDlystablefor a certainraugeof flowlate il1cleases massflow rate.Ifthe steammass too much,the condeDsate is ologgedin the hot-leg. Next, the coDdefsateis carriedover by the steam andpartially entrainedh the opposifedkectionto the steamgeneratot,This phenomenonis loto\'anas counter-clmentfiow limitation (CCFL). Futlet, a JunatM6inhn kdusti,wlun .?:!9y11:
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may provideaD studyof ds ffow connguration for ths safeq analysisoI impoflantunderstatrding the nuclearpowerplant, especiallyto estimatethe massflow ratein thehot legpressurized cotrdensate water reactorduring the CCFL. The CCFL io the real size of a ?WR hot leg was also extensivelystudiedat the Upper Plenufl Test Facility ([PTF) Germany (see tlrc UPTFFachtagungIV (1993)).Althoughthepbenomenon is well kDown, CFD codes are still not able to Dredict CCFL, which would be higlly desinble io understandthe effect in more detail and to increaseihe fl€xibility of predictioDs(Pmsseret al.. 2006). As far as the presentautho$ know, comtet-crurent flow experimentsin a horizodtal rectangularcharEelcomectedto a!. inclined riser as a model of a hot leg PWR has not yet been caried out. Theobjectiveoftheseexperimentswasto get a databaDkof the counter-ctmentffow limitatlon experiments, prhcipally for code verificatioo Druposes.In the paesentrepolt, the expeflmeffar i""olts of vi.uul obseffationsbefore and around the onset of flooding \rill be presentedfust' This datawil be explaited in tetms of the locus of the hydraulicjump anddevelopmentofthe liquid slug aroundthe oDsetof flooding. Next, the hystercsis phenornenaon flooding will be evaluated
2. EXPERIMENTALA?PARATUSANI) PROCEDURES in this paper, To simplirythe explamtion some abbreviations are used for the testing compoomlsas follows: SG simulator. a vecsel simulatilg the steamgeneFtor;RPV slmul|tor, a vessel thereaclorpressurc vesselsimulaliog A schematicdiagram of the erQerimetrtal is shownin Fig l . Themair1comporcnts aDDa.ratus consistedof the test section, ao RPV simulator located at the lower end of horizontal channel, an SG simulrtor locatedat th€ upper etrd of the inclbed chaorel, air supplt water supply ard a dataacquisitionsystem The test sectionreprcducesa 1:3 in vertical directionofthe hot-legofa PWRftod the Germa'n Konroi tpe- The test section has a rect4ngular cross sectionof (0.05x0.25)m? as showa m Fis.2.The lensrhsof Lbehorizonlaland incLined ,.iranzulatoartsof testsecrionwere2.12m and 0.23 ri, respectively.The inclination angle of the dser was 50' to hodzontal plaDe The inner a[d outerbeDalradii of curvatrlrewele 0.25 m and 0.5 m, lespectively.The test sectioDwasmainly made of stainlesss€el, and was equippedwith glass walls in the bendedregion of the hot leg and the steain soneratoridet chanber to permit visual
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observatiotras shown in Fig.2. Flow behaviors were recordedby a high sp€edvideo camem.The ftequencyaDdthe shutterspeedwere 100 Hz and 1/1000s respectively. Both the SG and RPV sidulators were identical vesselswith 0.8 m x 0.5 d x 1.5 m (D x w x II) cubic shape.The water levels i{ both vesselswere determinedby the measuremetrtof the differsdtial pressurebetweenth€ top atrd the bottom of the vesselswith differentierlpressure transduoers.A vodex meter was usedto D€asule the iDj€ctedwate! massflow rate.The injectedair flow mtewasm€asuedandcontrolledushg a n1ass themal massflow meter.The down-flowitrgwater massflow rate was detcmined by calculatingthe increaseof waterlevel of the RPv simulator. The waterlevel insidethe SG simulator wasmeasured to check th€ mass balance. The tempemtures botl of the air atrd water werc measuredby tlermocouples.The differeltial pressurebetween the SG aod R'PV timulators was measued by a differential pressure tratrsduce!.The data of differetrtial presstlle,the water levels imide both of the SG and R.PV simul4tors, injection mass flow rate both of the air and wate! tempemtures both of the air and wEter, and the air pressue inside the test sectionsignalswere traosnttted to a persoDalcomputervia a dataacquisitionsystem running at I Hz. the aboveapparatuswas put in a pressue chahber as shorvnin Fig.3, whereit was operated
in pressureequilibriub with the itaer atmosDhere of the tanl, A coDpressorsystemallows an increaseof the air prossurein the chambetto a ma"Kimumof 5 MPa, which is also the maxinun opelatiotrpressue ofthe hot leg model, The air was injeotedin the RPV simulator and flowed through the t€st section to the SG simulator, ftom which it was releasedto the atmosphereof the pressurechaober Water was pumped fiom the feed water pump to the SG simulator, ftom whele it can flows m coutrtercrrrletrtto the air flow thrcugh lhe test sectionto the RIV sidulator. The onset of floodiog was obtainedby a stepv.iseincreaseof the air ntass flow ratewith a small incre&ent,rmdera cotrstant water massflow mte. The onset of flooditrg was defined as the limititrg point of stability of tle coutrler-curreDtfow, iadicatedby tle maximum air massflow rale at whicb tbe down-Bowing water rtrassflow late is equal to the iDl6t water tnassflow rate.This methodwasusedby prelrous investigatorssuchas by Zabaras& Drkl€r (1988) and Deendarliantoet a1.(2005).The experimedts were caxried on urtil the point of zero-liquid pmeEarion appears,wben the down-flowing water massflow mte wasequalto zero.Ia orderto investigatethe hystercsiseft'ects,the experime[ts were alsoperforded by a stepwisedecreaseof air massflow !ate, rmdera constatrtwater massflow mte, until the total precipitationofthe watermass flow rate.
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Test section Fig.3.
The expedmeltal conditions llere as follows: - working fluids: air and water - \ratermassflow rate:fiL = 0.1-0.9kg/s - airmassflow €te: rhc =0.1G{31kg/s - workiDgfluid temperatures: approximately20' C - systempressure: 0.15MPaa.nd0.3MPa 3. RESIII,]TS & DISCUSSION 3.1.Flow behaviorin the betrdedregioDoflhe hot leg model 3.1,1.Flow behaYioraroundthe floodidg Fig.4 showsthe lrleasuledalataofthe water levelsinsideboth ofthe SG al1dRPV sim[laton' prcssruedifferencebetweel the two vesselsand injected air massflow Iate to tho test section at
(l) The slop€softhe curv€sofwater level in the RPV sidulator canbe alsodivided into tbree regions.In Region I, the water levels in lhe SG and RPV simulators increasesarrd ls coDstantwith theinueaseofai! massflow Gte, respectively.Th€ pressurediffercrce between the vessels inqeases slightly we defined this region as the stablecounter-crrlrentflow It shouldbe troticed that the flow pattem m this rcgion is stratified of supercriticalfrow' Supeicriticalfl owmeaDsthatthefi lrnthiclness increasesv.ith the water flow direction;while the film velocity decreases(the local Froude number(Fr) of the liquid film is larger than uniry). Meanwhile the hydraulicjunp as the tra$itioD from supercritical to sub_critical flow is not detectednear the bendedleg1on as low liquid mass flow rate reported by el al (2007) The discussion Deendarlianio regardinglocatio! of rie hl drauJicjump udderthis flow condition will comelatei.
ii1, :0.3 kgls and the systompresswewas 0.30 MPa. The water levels inside bolh of the vessels are shown in the upper gaph. The pressure (2) At an injectedair massflow rateof0.28 kg s (Fig.4: t=78.3 s), a limitation of counterdifferencebetweenthe vesselsandthe injectedair figule graph ofthis curcnt flow is detected,as marked as the the lower massflort Iat€ are in of onsetoffloodinginFig 4 Closeinspection It is notedthat: tt*indartndusti,\btuner: Jutnat
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the igure revealsthat tle behavior of water levels changesa litde with increasingwater massflow mte. At the iritiation of flooditrg, the slopeofwater level ir1the RPV simulator begils to deorease. Meanwhile,thewaterlevel in the SG simulator remairNalnost relatively const3nt.This phelommon is malked as A in Fig.4. This meansthat a part ofthe liquid does not flow to eif.herof fte l^ttks. Theqrestion is whercdo thewolerslaysSTo understaldltis phenomenoD,visual observatioostaken by a high speedvideo camerawerc conducted. The result is shol,ll in Figs.s(b). Fig.s(b)(l)
shows the flow behavior at the idtial stage of flooding. Close observationof this figure indicates that d water slug is detectednear the betrd without atry indicatioa of liquid drcplets. As tide goes b, tle water slug inoreasesitr height a4d Eoves to the bend also rvithout any dropleh ia the air flow direction. This phenomenonis clearly shown h Fies.5(bX2HbX3). This !1eans that the deoreaseof the slop€ of water level in RPV simulator is causedby the accumulationof water in the t€st section.The accumdlation of the water does Dot flow in the air flow
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dtectiotr; ooDsequely the water level in the SG sidulator rcmairN relatively coNtant. An adalogyb€tweenthe aboveexplanationof Lheliquid slug movementatd rhe bydraulic jump caobe made.That is, beforeth€ onsetof floodi[g, the hydraulicjunp wasnot detected
near the bmd becauseits locustloves itr lhe horizontalchamel to the R.Pv silxul.tor. As the air massflow rate is increasedarould Lhe onsetoffloodhg, thehydmulicjuhp increases itr heipht addmovesto the bend.
(2) t=63.5s (1)t=62.3s = (a)Beforetheonsetofflooding(rhn 0.26kgls)
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(3)F79.2ss offlooding(rirn= 0.28ke/s) O) At theonset F'ig.s, flo\{ ol air-wat€rathighwat€rflow mte Flowbehaviordudngth€counter-curr€nt (ril, = 0.9k8/s,atrdP=0.30IDa). votu|er. NoFt 1. 1q2 Jutnatu5;n dantndusni. t tI -704XHal.187-191 EdieJanuan 2A|A. ll;SN1693
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(3) The zem liquid penekation is reachedwith firther inoreasingof the ail mass flow €te up to 0.32kgls (Fig.s:F97.3 s). The visual observatioosindicatedthat in this region (Regiotr u), the flow behavior is similar to that at lower wate! massflow late ( rilL = 0.3 kC/s).
flow mte rcaohesa value Elloh lower thatr the flooding liquid massflow. This cotrditiotris called the defloodingpoint.
IE the prcsent experihetrtal studt the hysteresiseffectwas studiedby keepingthe water massflow rate constant while the air massflow rate was decreased.The oDsetof the deflooding was defined as the maximum air massflow late, Some additional remarks are addedat this at which the down-flowing watet rnassflow Iate point regarding tbe flow behavior during the courfe!-curetrt flow of air-water two-phaseffow begi$ to be equalto the injectedwatermassflord in a hoizontal recta.ngularchamel contrectedto mte. A t?ical set of results of the water levels inside both of the SG and RIY simulators, a.nhcliDed liser: pressEe differenceb€tweenthe two vesselsaod 1. Before the onset of flooding, a hydradic jump is observedclose to the bend at lower inj ectedair massflow rateto thetestsectionduring deflooditrg is shown ir Fig.6. Here the irjected liquid mass flow rate. Hydmulic jump water massflow tate aad systempaessurew€Ie appems,however,in the horizontalpart of the set at drr=0.9 kgls and P=0.3MP4 respectively. recta[gular channelv/ith high€r water rtrass Sevenl pictures il the bendedregion were also flow late. That is, the locationof thehydnulic jump movesto the horizontalpart ofthe test takeD by using a high speedvideo cameG to illustratethe fiow behayio( and sorneof theseare sectionwith the increaseof water massflow showr1in Fig.7. The obseped phetromenaale as rate. follows: 2. The inception of flooding in a horizodal (l) In the Fig.6, it is cleady shown that the r€ctangularchann€lco lected to an inclined slopes of the cuwes of the water level in riser coincides with the formation of slug the R?V simulator can be divided inlo six flow At this point, the pressureilrop along regions. Itr the fust region (Fig.6: F0 - 26 the test section begins to inclease. F.om s), the wate. level ir the RPV 6iEulatcr is this observation, it is concluded that the alwayscoDstantwiih the decreaseof ail mass occu(ence of slug dow and the staftlg flow rate. Meanwhile the water level in the irfiease ofth€ pressurediference areintegml SG simulator increasesas the decreaseof phenometraofthe initial stageofthe flooding air mass flow rat€. This meansthat all the duringthe counter-curentflow ofair-water ir j4ject€d water flows to the SG simulator. a hodzontalrectangllaachannelcormectedto This conditioncorespondsto the zero liquid an inclined riser penetratioDasdiscussedpreuously. Theaboveresultsaresimilarto thoseobtahed (2) h the second.egion(Iig.6: t-26 - 80 s), by Siddiquidetal. (1986)andWong{ises(1996a) the water level in RPV simulator begins to who elominedtheflow behaviorduriagfloodingin increasewith the deqeaseof air massflow a horizontalpipe with a bend.This mea.nsthat the !ate. The avemge discharge watel mass flow behavior ill a PWR hot leg doesrot change flow mte in RPV simulator is 0.05 kg/s. sigtificantly if the test sectioDgeomefy changes From visual observations,it is rcted that the ftom the pipe to rcctatrgularcha 1e1. droplets appearedir the holined riser and 3.2.2. Hysteresisb€tweedflooding atrd carried upward lo lhe SG simLrlatorby air deflooditrg st eam.The carry over of liquid in the form of large wave fiom hoflzoDtalpafi to the SG The rcxt discussionrefe$ to the countersimulatorwas not found here.Thereforeit is curent flow €xpedment aimed to studfng the possible to concludethat the taDspottation hyst€rcsisphetrornenotr. Celata€t al. (1991)noted of liquid dlrilg this flow condition is in the that an hysteresiseffect occurs,oucethe onsetof fonn of €ntrainment liquid droplets. This floodiag hasbeenreached,and eitherthe liquid or phelomenotr is captued o[ cadera alld is the gas massflow rate is decreasedwith the arm shown ir Fig.7(a). This poidt is marked as of restodng a.nundisturbedcounter-crrllentflow. A on the prcssue drop plot (Fig 6), and it The flooding condition persistsutrtil the reduced 1,| r, Nonot Junetttsindartndusbi, votnne
-701X,Hal167'197 Edisi Jaruad201A.ISSN 1693 | tr9,3
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catr be seenthat the pressuredrop uder this flow conditioDis quitehigi. This region corresponds to thepaxtialdeliveryregionas notedabove.
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(a) riro = 6.39 Lntt
(b)dtc = 0.27ke/s
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FrC.1. the deflooding exp€riment at mz =0.90kglsandP=0.30MPa. Flowb€haviorduring
(3) In tle tlird region (Fig.6: F80 - 107 s), the slope of water level in the RPV simulator is higher than the prcvious rcgion. The averagedischarge_watermass ffow rate in Rlv sidulator (rhr.D) is 0.44kg/s.h thrs region.ir wasobsenedthatlbe dropletfux rs smaller than the previousregion. Meanwhile tle averagefilm thickress in the horizontal part is higher than that the previous rcgion. This phenomenon is showt in Fig.7(b).The pressrredrop becomesvery high (poinlB ir) Fis.6).
(4) At an injected air massflow rat€ of 0.22 kg/ s (Fig.6: Fl07 s) the onset of defloodingis detected.Here the avemgedischargewater mass flow late in RPV simulrtor is 0.9 kg/s. h this region, the water level iq the SG simulator is alnost constant.The flow behavior within this flow condition appears to be chaotic with la.ge water slug being presentin the horizo al part. The blockage of the horizontalpart of test sectionby water slug canbe found occasionally.However,the enftainmentof liquid droplet still dominat€s i!t.:: !,t::j:: :)1thlt.!,ibl!n.t.:,81"1i
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the flow stuohue here. This phenomenonis captued on carnemand is shownin Fig.7(c). This point is mafked as C on the pressure &op plot (Fig.6), and it can be seenthat the pressue drop becomesvery high. Next the presswedlop dedeaseswith the decreaseof air Dassflow iate in this rcgion. (5) As the declease of air mass flow rate prcc€eded,the avemgedischargewatsr mass flow rate in RPV simulrtor is ! ch higher tban the injectedotre (rbr"_2.0 k9!) Ir is Diarl.edasthe resioooft-l4l s !o r=185s in Fig.6. The amountof this water comesftom the injected water mass flow rate and the acclu$rlation of water in the test sectioo.Id this rcgion, the droplet flux is lower than the previousregion, and the blockageprocessof wateria botizoDtalpart occulsoccasionally.It is shownclearly in Fig.7(d),ad is markedas D ir presswedropplot itr Fig.6. It is seenthat tle pressue drop is still high altlough it is trot higherthatrthe value of at point C. As tbe time goesby, the interfacialstructureb€comes stable.The ft€qu€ncyofwater slug decleases Gee Fig.7(e)), and a stable stmtified flow caa be found (seeFig.7(0). Furthermorethe pressue drop alsodedeasesastbe i{terfacial becomesstable.ThosearemarkedasE andF ia the pressuredropplot ia Fig.6.
4. CONCLUSIONS Tbe coull,er-curretrl flow limitations in a horizontal rectatrgularcha rel coniected to an hclilred riser as a ftodel of a hot leg pressurized water reactor were investigated experimetrtally. Theresultsme summarizedas follows:
03
&ozs
1. The liquid massflow lat€ affectsto the locus of the hydraulic jump, which is the hcrease of liquid massflow rate moves the locus of tlrc hydmulic junlp to the horizontalchannel. Meanwbile it is not affectedby the system pressrrle.
02
0i0
an example.Irom the fgure, it is doted tiat an hysteresiseffectappearsinth€prcseexperimental study.The values ofthe defloodingair massflow mtearemuchlowertha! rrithrespecttotheflooding odce.This toetrdis also similar to thoseby Hewitt & Wallis (1966)andBecker& Letzter (1978)who examinedthat effect in vertical pipes.To e,stabtsh the flooding, the air mass flow rate should be quite high itr order to maintail the momentum exchangebetweentlrc water atrdair flow. Arcund the flooding poir , a large water slw is developed tse€ Fig.5O)(2)1. Meanwhile in the deflooditrg condition, the hansportationof liquid is itr the form of entrainmentliquid droplets as discussed above(seeFig,7). Due to the weight of water slug is higher than that of lquid droplet, therefore,to break down the fquid slug requircsmuch higher ak ttrassflow rate than to changethe flow forh ftom cary-over of liquid droplet to a stable counter-cufientflow. Consequeltlyit is expected to lead a hysteresiseffect. Next th€ hysteresis efrect becomesmore important when irlcl€asrng the water hass flow €te as sho\rn h Fig.8. This trend is also in agreeme with Icolewski (1980) who remarkedthe strotrghysteresiseffect car! be found in higher water massflow rates during the counter-curetrt flow of afu-watertwo-phaseflow ir a complex piping system simulating truclear reactorhot leg.
025
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tm
Fig.8. Hysteresisetrectobserv€dbetweenflooding and deffooding(P = 0 30 M,a). Fig.8 shows the hystercsis effect observed between flooding and deflooding in the present
The idtiation of flooditrg ia a horizontal rectatrgularchannelcobnectedto an i&1ined risercoincideswith the formationof a Iiquid slug nearthe beDd.
3 . The hystercsisefrect appearson the onsetof flooding, and the hysteresiseffect becomes more important when increasing the water massflow !ate.
study.The systempressurewasP:0.30 MPa,as .tuarl M*ir dentNtusi. thtuae7 Nont 1 a, Of - 7Nv X"1 167.197.-J EdtsiJtn8d 2OlO. ISSN 1593
andSuhanen Deenclailanto
REFERENCES Beoker, K.M., Letztot, A., 1978. Flooding and deflood$g measuredetrtfor oount€r-current flow of ail and water in vertical channels. ReportKTH-NBL-2s. Celata, G.P., Cumo, M., Farcllo, G.8., Setaro, T., 1991. Hysteresis effect in flooditrg. Iltematioml JournalofMultiphase llow 17, 283J89. Deendarlianto, Ousaka, A., Katiyasaki, A., Fukarc, T., 2005. Itrvestigation of liquid fiLa behaviorat the onsetof floodiag during adiabaticcount€rcurrentah-water two-phase flow i! atrinclinedpipe.NuclearEngineering ar.dD esien235, 2281-2294, DeeDdarlia[to,Vallee, C, Lucas, D., Beyer, M., Ca , H.,2N7. Experimental study on the cormter-cufieotflow limitations (CCFL) of air-watertwo-phaseflow itr a modelofhot leg pressudzedwater reactor.Submitt€dpaperto NuclearEngineedngandDesiga Hewitt, G.F.,Wallis, G.B., 1966.Floodi4 and phenomena ir: falli-ngfilmflow ha associated vertical tube.LTKAEAReportAERE R-4022. Krolewski, S.M., 1980. Flooding limits i! a simulated nuclear leactor hot leg. Massachusetts Iostitute of Tecbnology, Subdrissiooas a part of rcquirernetrtfor a B.Sc. IV: Versuchselgebnisse, IlPfi-Fachtagung 25.Marz ls9J. Siemen Analysen.Mann-beim 1993. AG, KWU, KWU R 1l 1931005, Wallis G.B,, 1969. one-dimeNional two-phase flow Mc Graw-Hill. zabaras,G.J.,Dlkler, A.8., 1988.coutrter-ounent gas-liquid annularflow, includingtheflooding state.AIChE Joumal34 (3),389-j96.
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