资源描述:
《远红外辐射场优化与匹配度计算的研究 毕业论文》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、远红外辐射场优化与匹配度计算的研究摘要本设计的特点为采用远红外烘干,主要利用能量为远红外辐射能,由于辐射能的传输不需要介质,辐射能的传输效率较对流高,所以在本设计中不考虑对流换热的影响。设计目标是提高烘烤的效率与质量,实现方式为优化辐射场以及提高匹配度。烘烤对象为汽车表面喷漆,溶剂为二甲苯。本设计通过对测试屏上的点每隔一定步长分别计算其获得的直照度与反照度,并计算出测试屏上各点的总照度的最大值与最小值,将最大值与最小值之差作为评价辐射场均匀度的指标。通过调整辐射管中心线的位置以及相临两个反射罩的距
2、离,使均匀度的评价指标值最小,这时,辐射管与反射罩的位置参数即为最优参数。其中,每一计算点的直照度用推导出的直照度积分函数通过Romberg积分[1]求得,反照度则用离散化思想,将反射罩抛物柱面离散化,根据光线可逆原理,对测试屏上每一计算点逆向反求辐射管上的辐射点,然后采用与直照度相似的方法求得辐照度。本设计还利用Romberg积分函数对光谱辐射力和相对应的吸收比采用分段积分的方法对二甲苯的最佳匹配吸收温度作了理论计算,得到了合理的结果。关键字:远红外;辐射场优化;匹配度优化-86-Researc
3、hontheoptimizationofinfraredradiationfieldandmatchingdegreeAbstractInfraredradiantenergyfeaturesinthedesignofinfrareddryingstove.Becauseincontrastwithothermodesofheattransfer,nomediumisrequiredtotransmitradiantenergy,soheattransfercoefficientsforradia
4、ntenergyaregenerallymuchhigherthanconvection.Inthisdesign,theinfluenceofheattransferbyconvectioncanbeignored.Thesolutionofthepaintonthesurfaceisbenzene.Theaimofthedesignistoimprovetheefficiencyandqualityofdrying,sothemaintaskistooptimizetheradiationfi
5、eld,thatistosay,minimizethedifferenceofemissivepowerreceivedbythesurfaceofcars.Forafixedverticalsurface500mmawayfromthebottomofthereflectionsurface,inordertoindicatethetemperaturefieldonthesurfaceisoptimized,weneedtocalculatetheemissivepowerreceivedby
6、everypointonthesurface.Tosimplifyourtask,wedividethesurfaceintosmallsurfaces,andassumethatemissivepowerreceivedbyeachsmallsurfacecanbeconsideredtobeintegratedintothemiddlepointofthesmallsurface.Onthisassumption,weonlyneedtocalculatetheemissivepowerrec
7、eivedbytheseselectedpoints.Thenwecanfindthemaximumandminimumvaluesofemissivepowerreceived,andmakethedifferenceofthemtheindicationofoptimizationofthetemperaturefieldonthesurface.Givenapairofparameters,suchasthedistanceoftwoimmediatereflectionsurfacesan
8、dtheaxisoftheradiantunit,wecangetaindicationvalue.Iftheindicationvalueisminimum,thecorresponding-86-parametersaretheoptimizedones.Besides,emissivepowerreceivedbyeachselectedpointcanbedividedintotwoparts.Onepartisemissivepowerreceiveddirectlyfr