食品高壓處理過程水分相變及傳熱模擬.pdf

1、大連理工大學碩士學位論文食品高壓處理過程水分相變及傳熱模擬姓名：劉克剛申請學位級別：碩士專業(yè)：化工過程機械指導教師：李志義20090601食品高壓處理過程水分相變及傳熱模擬ModelingphasechangeandheattransferofwaterduringhighpressurefoodtreatmentAbstractBaseonthephasediagramofwaterhilghpressurefoodfreezinga

2、ndthawingtreatmentisimplementedbycontrolbothpressureandtemperatureduringthephasechangePressureeffectcansignificantpreservethemicrostructureofbiologicalsubstancesandreducephasechangetimebyincreasethethermalgradientsandred

3、ucetheicecrystalsizeAsurveyofthepreviousworkisfollowedinthisthesisbyadetailedreportonthenewstudyworkofthethermophysicalpropertiesunderhighpressurecalculation；pressureinducedthawingtimereduction；thermalevolutioninfluenced

4、byconvectioncurrentsinthepressuremedium；influenceontheformationoftheicefrontbyconvectivefluidmotionAmethodforthecalculationofsomethermophysicalpropertiesofbothliquidwaterandiceIunderhighpressureisimplementedTheseproperti

5、es，closelyinterrelatedintheirphysicalderivationandexperimentalmeasurementarethermalexpansioncoefficient，isothermalcompressibilitycoefficient，specificvolumeandspecificisobaricheatcapacityThelimitsforthesetofequationswhere

6、setin30to120℃and0to500MPaforliquidwaterand一30to0℃and0to210MPaforiceITheirgoodagreementwithmanyexistingexperimentaldataisdiscussedInaddition，theroutinesimplementedforthecalculationofthesepropertiesisnladebycommercialsoftw

7、areMATLAB111eroutinesareusedinthelatercalculationsAcomputersimulationWasconductedtoevaluatethawingtimereductionoficeduringhighpressureassistedthawingtreatmentandtheresultswerecomparedwiththoseunderatmosphericpressureTher

8、eleaseoflatentheatWastreatedbyapparentspecificheatmethodTheeffectsofthedifferentfactorsonthehighpressureassistedthawingtreatmentwereanalyzedThetimereductionsofdifferentsampledimensionswereestimatedandthetemperaturecontou

9、rofthawingatdifferentoperatingconditionsWasobtained，nleresultsshowthatthetemperaturegapofphasetransitionismainfactoreffectingthethawingtimereductionThesecondorderrelationshipCanbeconsideredbetweenpressureandphasetransiti

10、ontimeWiththeunfrozentemperatureboundaryconditiontwosamples、析ttldifferentfillingratioisstudiedbycouplingtheNSequationtoconvectionheattransferequation田1eresultsshowthatheattransferissignificantenhancedinthesmallersample(1