Characteristicsofheattransferwerein

Characteristicsofheattransferwereinvestigatedinathree-phasecirculatingfluidizedbedwhose
diameterandheightwere0.102m(ID)and2.5m,respectively.Effectsofgasandliquidvelocities,
particle size(0.5–3.0mm),solidcirculationrate(2.0–6.5kg/m2 s), andsurfacetension(47.53–
72.75103 N/m)ofliquidphaseontheheattransfercoefficientwereexamined.Itwasfoundthat
the heattransfercoefficient(h) betweentheimmersedverticalheaterandtheriserproperofthethree-
phase circulatingfluidizedbedincreasedwithincreaseingasandliquidvelocities,butdidnotchange
considerablywithafurtherincreaseinliquidvelocity,eveninthehigherrange.Thevalueofheat
transfercoefficientincreasedgraduallywithincreaseinthesizeoffluidizedsolidparticleswithout
exhibitingthelocalminimum,whichrepresentedthattherewasnobedcontractioninthree-phase
circulatingfluidizedbedsduetothehigherliquidvelocity.Theheattransfersystemcouldattaina
stabilizedconditionmoreeasilywithincreaseinparticlesize.Thevalueofheattransfercoefficient
increasedwithincreaseinsolidcirculationrateinallthecasesstudiedduetotheincreaseofsolid
holdupintheriser.Thevalueofheattransfercoefficientdecreasedwithincreaseinsurfacetensionof
liquid phase,duetothedecreaseofbubblingphenomenaandbubbleholdup.Thedecreaseinliquid
surface tensioncouldleadtoanincreaseinelapsedtimefromwhichthetemperaturedifference
betweentheheatersurfaceandtheriserbecameanalmostconstantvalue.Theexperimentally
obtainedvaluesofheattransfercoefficientwerewellcorrelatedintermsofdimensionlessgroupsas
well asoperatingvariables.

ผลลัพธ์ (ไทย) 1:

Characteristicsofheattransferwereinvestigatedinathree-phasecirculatingfluidizedbedwhosediameterandheightwere0.102m (ID) and2.5m ตามลำดับ Effectsofgasandliquidvelocitiesขนาดอนุภาค (0.5 – 3.0 mm), solidcirculationrate(2.0–6.5kg/m2 s), andsurfacetension(47.53–72.75 10 3 N/m) ofliquidphaseontheheattransfercoefficientwereexamined Itwasfoundthatbetweentheimmersedverticalheaterandtheriserproperofthethree heattransfercoefficient(h) การ-ระยะ circulatingfluidizedbedincreasedwithincreaseingasandliquidvelocities, butdidnotchangeconsiderablywithafurtherincreaseinliquidvelocity, eveninthehigherrange Thevalueofheattransfercoefficientincreasedgraduallywithincreaseinthesizeoffluidizedsolidparticleswithoutexhibitingthelocalminimum, whichrepresentedthattherewasnobedcontractioninthree เฟสcirculatingfluidizedbedsduetothehigherliquidvelocity Theheattransfersystemcouldattainastabilizedconditionmoreeasilywithincreaseinparticlesize Thevalueofheattransfercoefficientincreasedwithincreaseinsolidcirculationrateinallthecasesstudiedduetotheincreaseofsolidholdupintheriser Thevalueofheattransfercoefficientdecreasedwithincreaseinsurfacetensionofเฟสของเหลว duetothedecreaseofbubblingphenomenaandbubbleholdup Thedecreaseinliquidผิว tensioncouldleadtoanincreaseinelapsedtimefromwhichthetemperaturedifferencebetweentheheatersurfaceandtheriserbecameanalmostconstantvalue Theexperimentallyobtainedvaluesofheattransfercoefficientwerewellcorrelatedintermsofdimensionlessgroupsasasoperatingvariables ดี

ผลลัพธ์ (ไทย) 2:

ขนาด (0.5-3.0mm) solidcirculationrate (2.0-6.5kg / m2 s), andsurfacetension (47.53- 72.75? 10? 3 N / m) ofliquidphaseontheheattransfercoefficientwereexamined.Itwasfoundthat heattransfercoefficient นี้ (เอช) betweentheimmersedverticalheaterandtheriserproperofthethree- เฟส เฟส duetothedecreaseofbubblingphenomenaandbubbleholdup.Thedecreaseinliquid พื้นผิว asoperatingvariables

ผลลัพธ์ (ไทย) 3:

characteristicsofheattransferwereinvestigatedinathree phasecirculatingfluidizedbedwhose
diameterandheightwere0.102m ( ID ) and2.5m ตามลำดับ effectsofgasandliquidvelocities
, ขนาดอนุภาค ( 0.5 – 3.0mm ) solidcirculationrate ( 2.0 ) 6.5kg/m2 ) andsurfacetension ( 47.53 –
72.75  10  3 N / m ) ofliquidphaseontheheattransfercoefficientwereexamined itwasfoundthat
.การ heattransfercoefficient ( H ) betweentheimmersedverticalheaterandtheriserproperofthethree -
เฟส circulatingfluidizedbedincreasedwithincreaseingasandliquidvelocities considerablywithafurtherincreaseinliquidvelocity butdidnotchange
, ,

exhibitingthelocalminimum eveninthehigherrange . thevalueofheat transfercoefficientincreasedgraduallywithincreaseinthesizeoffluidizedsolidparticleswithout ,whichrepresentedthattherewasnobedcontractioninthree เฟส

circulatingfluidizedbedsduetothehigherliquidvelocity . theheattransfersystemcouldattaina stabilizedconditionmoreeasilywithincreaseinparticlesize . thevalueofheattransfercoefficient

increasedwithincreaseinsolidcirculationrateinallthecasesstudiedduetotheincreaseofsolid holdupintheriser .thevalueofheattransfercoefficientdecreasedwithincreaseinsurfacetensionof
ของเหลวเฟส duetothedecreaseofbubblingphenomenaandbubbleholdup . thedecreaseinliquid


theexperimentally พื้นผิว tensioncouldleadtoanincreaseinelapsedtimefromwhichthetemperaturedifference betweentheheatersurfaceandtheriserbecameanalmostconstantvalue .obtainedvaluesofheattransfercoefficientwerewellcorrelatedintermsofdimensionlessgroupsas

asoperatingvariables อย่างดี