Venlo型溫室自然通風(fēng)降溫的實驗研究與CFD模擬.pdf

1、中國農(nóng)業(yè)大學(xué)博士學(xué)位論文Venlo型溫室自然通風(fēng)降溫的實驗研究與CFD模擬姓名：李永欣申請學(xué)位級別：博士專業(yè)：農(nóng)業(yè)生物環(huán)境與能源工程指導(dǎo)教師：李保明20031201AbstractThecoolingeffectsofshadingandroofsprinklinginanaturallyventilatedVenlotypegreenhouseareexperimentallystudiedinsummerAirtemperature

2、andhumidityaremeasuredatverticalandhorizontalplanesinsidethegreenhouseTheresultsshowthatshadingandroofsprinklingcalleffectivelycooldownthenaturallyventilatedgreenhouseinsummerinthecentralpartofChinaUridertheexperimentalc

3、onditionstheaverageindoorairtemperatureis21℃lowerthanthatofoutdoorthelargestairtemperaturedifierenceis44℃TheairtemperatureisdecreasedwithoutincreasingofairhumidityinsidethegreenhousewiththeroofsprinklingsystemTheresultsa

4、lsoshowthatthecombinedventopeninghastheadvantageoverthewindwardortheleewardventopeninginthegreenhousecoolingGoverningequationsofComputationalFluidDynamicsareappliedfornaturalventilationinaVenlo—typegreenhouse，whichinclud

5、ethecontinuityequation，theNavierStokesequationandtheencrgYequationTherealizableketurbulencemodelfoundedbvtHShihandW、ⅣLiouin1995isappliedinturbulentflowstudyTheboundaryconditionsofCFDmodelingarepracticallytreated，whichinc

6、ludeclimateconditions，greenhousecoveringandwall，shadingandsprinkling，vegetableandsoilInthisstudy，theCFDmethodisappliedtosimulatethecoolingprocessofshadingandroofsprinklinginanaturallyventilatedVenlo—typegreenhouseTheCFDm

7、odelingresultsoftheaverageairtemperatureinsidethegreenhouseare17℃higherthanthemeasmingresultsThedifierencebetweenthemodelingdataandtllemeasuringdatais5％ThemodelingresultsagreewellwiththemeasuringresultsThemodelingresults

8、aisoshowthatthecombinedventopeninghaveasignificantadvantageinthegreenhousecoolingcomparedtowindwardorleewardventopeningTheairflowthroughtheroofventsinanaturallyventilatedVenlotypemulti—spangreenhouseisnumericallysimulate

9、dbvCFDmethodsneinfluencesofwindeffect，thermaieffectandcombinedwindand也ermaleffectonventilationfluxandinternalairflowarestudiedrespectively111emodelingresultsshowthattheairflowdrivenbywindissignificanttoairexchangeandinte

10、rnalairflowandthethermalbuoyancyeffectislimitedTheventilationfluxintemalairspeedareinproportiontothewindspeedTheresultsalsoshowthattheventilationfluxinVenlotypemulti—spangreenhouse、Ⅳi血combinedventopeningishi曲erthanthatwi