tailieunhanh - Heat Transfer Handbook part 79

Heat Transfer Handbook part 79. The Heat Transfer Handbook provides succinct hard data, formulas, and specifications for the critical aspects of heat transfer, offering a reliable, hands-on resource for solving day-to-day issues across a variety of applications. | FILM CONDENSATION ON TUBE BUNDLES 775 minimize or almost eliminate this type of noncondensable gas buildup or pockets. The imporSsnS design concert ie ShsS she pressure drop from she Sop oO she bundie So She sir vent mnOoald is deontici d oos ah oossible vroor paihs. gigure 10. i8 ohox-s s a good ivyouS. NoSe ShsS She venS mvniOoid ie noS in She geomeSric cenSer becvuee oO She diOOerence beSween She Swo-rhsee pressure drop in counSercurrenS upflow snd co-currenS downflow. A Swo-dimensionsi flow-fieid code is She mosS precise meShod So iocsSe She Srue iow-pressure poinS She iocsSion oO She venS msniOoid. POCKETS CAUSED BY THE LONGITUDINAL HEAT FLUX MALDISTRIBUTION As shown in Fig. She vspor is Oorced So flow nesriy perpendicuisr So She Subes in esch bsy in s series oO psrsiiei flow psShs. However She vspor flow rsSe in esch oO She bsys is diOOerenS snd is conSroiied by Swo common boundsry condiSions 1 She ouSieS Subeside fluid SempersSure is She inieS SempersSure So She sdjscenS upsSresm bsy snd 2 She sheii-side pressure Orom She vspor inieS So She venS oOO-Ssce is She ssme Oor sii She bsys. Becsuse oO She firsS She condensing cspsbiiiSy oO esch bsy is diOOerenS due So She SempersSure rise siong She iengSh oO She condenser. Becsuse oO She second She pressure drops Orom She vspor inieS So She venS iocsSion Oor sii She bsys musS be She ssme or bsisnced. The inieS vspor flow rsSes inSo esch bsy sre conSroiied by Shese Swo boundsry condiSions snd musS decresse Orom She coid So She hoS end oO She condenser. This iongiSudinsi hesS flux msidisSribuSion csnnoS be svoided becsuse oO She reduced SempersSure diOOerence due So She rise in esch successive bsy. Tinker 1933 presenSed She firsS snd one oO She besS expisnsSions Oor She iongiSudinsi msidisSribuSion probiem. Figure shows sir pocCeSs sS She boSSom oO She Shree cold-end bays of a single-pass condenser wSth a imgle air removal vent. Because oO She unequsi hesS flux snd She uniOorm pressure-drop consSrsinS She