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1、中國石油大學(xué)(華東)碩士學(xué)位論文焦炭塔給水冷焦過程的研究姓名:張文鐘申請學(xué)位級別:碩士專業(yè):化學(xué)工程指導(dǎo)教師:肖家治;王蘭娟20090501摘要論文從多維非穩(wěn)態(tài)傳熱微分方程出發(fā),自行推導(dǎo)了圓柱坐標(biāo)系下的二維非穩(wěn)態(tài)傳熱主控方程,建立了內(nèi)節(jié)點(diǎn)全隱式離散方程,由附加源項(xiàng)法得到了邊界節(jié)點(diǎn)離散方程,選擇交替方向隱式算法ADI和三對角陣算法TDMA作為代數(shù)方程組求解的方法。以焦炭塔焦層為研究對象,假定成型焦層為中間孔道結(jié)構(gòu),運(yùn)用控制容積法對中間孔道焦層模型不同放熱模式進(jìn)行了數(shù)值計(jì)算和分析;以VisualBasic為平臺(tái),采用面向?qū)ο缶幊碳夹g(shù),編制了含焦焦炭塔溫度場計(jì)算程序;根據(jù)焦層降溫放
2、熱量等于冷焦水吸熱汽化量的事實(shí),結(jié)合現(xiàn)場冷凝水實(shí)際產(chǎn)生量最大點(diǎn)及流量范圍,從三個(gè)放熱模式中篩選了相對接近現(xiàn)場實(shí)際的考慮了冷焦水在焦層表面汽化傳熱過程的沸騰給熱模式。針對沸騰給熱模式,探討了網(wǎng)格、焦層物性、沸騰給熱系數(shù)等對焦層溫度場、焦層放熱量及冷焦水汽化量的影響,結(jié)果表明:考慮不同空間不同時(shí)刻焦層汽化能力差異是必要的,時(shí)間步長、徑向和軸向網(wǎng)格特別是徑向網(wǎng)格對初期冷焦水汽化量影響明顯;焦層物性參數(shù)中,焦炭導(dǎo)熱系數(shù)對冷焦水汽化量的影響最大,比熱容次之,密度影響最小;沸騰給熱系數(shù)、流體主體溫度對冷焦水汽化量的影響不大;焦炭塔塔徑由6m增大到8.8m,放空系統(tǒng)能力要提高13%左右;如
3、果增大到9.4m,放空系統(tǒng)能力要提高15%左右。關(guān)鍵詞:延遲焦化,焦炭塔,放空系統(tǒng),給水冷焦,非穩(wěn)態(tài)傳熱,中間孔道模型StudiesonCokeCoolingProcessinCokeDrumZhangWenzhong(ChemicalEngineering)DirectedbyProf.XiaoJiazhiAssociateProf.WangLanjuanAbstractOnthebasisofthemultidimensionaltransientheattransferdifferentialequation,two.dimensionaltransientheattr
4、ansfergoverningequationinthecylindricalcoordinatewasderived.Fullyimplicitdiscretionequationofinnernodesanddiscretionequationofboundarynodesbymeansofadditionalsourcetermmethodwerebuiltup,too.ThesolutionofalgebraicequationsWasalsoaccomplishedwiththehelpofalternatingdirectionimplicitandtridiag
5、onalmatrixmethod.Takingcokesincokedrumastheresearchobject,asimplifiedmiddle—channelmodelwasbuiltup.Thenthemathematicalmodelestablishedinthispaperwasnumericallyanalyzedusingfinitevolumemethod.VisualBasic6.0wasusedtoprogramtocalculatethetemperaturefieldsofcokesincokedrum.Theobject-orientedpro
6、gramminglanguagewasusedinthedevelopmentofthisprogram.Accordingtothefactthattheexothermicamountofcokeisequaltotheheatabsorptionamountofwater,combined塒tllthemaximumevaporationpointandthefluxrangeofcondensatedwater,themodelofboilingheattransferwasselectedfromthreeexothermicmodels.Themodelofboi
7、lingheattransfertakestheprocessofwatervaporizationandheattransferintoconsideration.Theinfluenceofgridnumber,cokepropertiesandboilingheattransfercoefficientonthetemperaturefields,exothermicamountofcokesandvaporizationamountofwaterWasanalyzedinthemodelofbo