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毕业设计论文姓名：孙晓春学号：0902050303学院：能源与动力工程学院专业：热能与动力工程题目：330MW大型锅炉过热器系统热偏差分析与计算指导教师：刘洪宪讲师2013年6月摘要I题目330MW大型电站锅炉过热器热偏差特性分析摘要随着电力工业的发展，火力发电机组的装机容量日益增大，300MW、600MW机组已成为电网中的主力机组，这部分机组运行质量的优劣对整个电网运行的可靠性、经济性有着非常重要的影响。过热器和再热器作为锅炉机组重要的部件，其可靠运行无疑对整个机组的安全运行有着非常重要的意义。随着机组容量的增大，锅炉过热系统因热偏差引起的超温爆管事故频频发生，严重影响了发电厂的安全、经济运行。鉴于上述原因，关于热偏差的成因及热偏差、壁温计算方法的研究就具有非常重要的实际意义。但多数人员对热偏差成因的研究多侧重于某一方面，很少对热偏差的成因进行全面、系统的理论分析；而且我国许多锅炉制造厂普遍采用原苏联热力计算标准方法来计算壁温，这种方法对于过去容量小、参数低的锅炉机组来说，计算结果还比较准确，但是对于现代大容量、高参数的电站锅炉来说，不可避免地带来一些问题。因此，论文在关于热偏差成因的综合理论分析基础之上，建立受热面合理的蒸汽流量分配计算模型、热偏差计算模型和壁温计算模型，摒弃原有计算方法中的不足，采取适于工程应用的计算方法，以实现准确地反映受热面出口汽温和管子壁温分布情况。同时，依据热偏差的成因提出相应的减小措施或预防对策。论文以吉林江南热电330MW亚临界锅炉机组为例，对建立的计算模型进行了实际应用，对引起热偏差的主要因素进行了分析。计算结果证明本文采用的计算方法较为合理，能够反映受热面的实际热偏差状况，对于过热系统受热面的优化设计、事故分析提供了一定的参考价值和实际指导意义。关键词：锅炉；过热器；热偏差；壁温；超温爆管东北电力大学本科毕业论文IITitle330MWboilersuperheaterdeviationcharacterizationABSTRACTWiththedevelopmentoftheelectricalindustry,theinstalledcapacityofthethermalpowergeneratingunitisaugmentingincreasingly.Thegeneratingunitsof300MWand600MWhavebeenthemainonesinthepowernetwork.Whetherthesegeneratingunits′operationissuperiorornotwillhaveagreatinfluenceonthedependabilityandefficientperformanceofthepowernetworkoperation.Thereliableoperationofthesuperheaterandreheaterthatarethekeycomponentsofthelarge-capacitypowerstationboilerisverysignificantforthewholeunitswithoutdoubt.Withtheenlargementoftheinstalledcapacity,theoverheatingandtuberuptureoftheboilersuperheatsystemfrequentlyhappenbecauseofthermaldeviation,whichseriouslyaffectsthesafeandeconomyoperationofgeneratingplant.Onaccountoftherelatedfactabove,researchintothecausesofthethermaldeviation,thecalculationmethodofthethermaldeviationandthewalltemperaturearegreatlyimportant.Butmostresearchesintothecausesofthethermaldeviationoftenarethrownintosomeaside,fewcarryoutanall-roundandsystematictheoreticalanalysis,andmanymanufacturescalculatethewalltemperaturepopularlyaccordingtotheoldstandardmethodabouttheheatcalculationoftheSovietUnion,thismethodissuitableforthelastboilerunitofsmallcapacityandlowparameter,butastolarge-capacityandhighparameterpowerstationboilerstoday,itwillbringsomeproblemsinescapably.Atthesametime,accordingtothecausesofthethermaldeviation,themeasuresorschemestodecreasethethermaldeviationhavebeenputforward.Thisdissertationputsthecalculationpatternsestablishedintopracticaluse,takingthethermalconditionofthe330MWsubcriticalpressureconcurrentboileroftheJilinJiangnanPowerPlantasanexample,andgivesaprofoundanalysisonthemaincausesofthethermaldeviation.Thecalculationresultsofthethermaldeviationproveitappropriatethatthecalculationmethodistaken,fortheresultscanaccordwiththefactualthermaldeviationcondition.Sothisdissertationcanprovideacertainreferencevalueandpracticaldirectionfortheoptimumdesignoftheheat-exchangersurfaceandtheaccidentanalysis.Keywords:Boiler；Superheater；Thermaldeviation；Walltemperature；Overheatingandtuberupture目录III目录摘要..........................................................................................................................IABSTRACT................................................................................................................II目录........................................................................................................................III第1章绪论..........................................................................................................11.1课题背景.........................................................................................................11.2国内外研究成果和发展动态.........................................................................21.3课题研究的内容与方法.................................................................................3第2章过热器系统的热偏差理论分析..................................................................12.1概述.................................................................................................................42.2过热器热偏差概念叙述.................................................................................42.3烟气侧热偏差的原因.....................................................................................52.4蒸汽侧流量偏差原因.....................................................................................8第3章过热器热偏差基本计算方法....................................................................113.1概述...............................................................................................................113.2热负荷不均系数计算...................................................................................113.3热偏差计算相关参数的确定........................................................................143.4并联管组流量偏差计算...............................................................................173.5热偏差系数计算...........................................................................................223.6金属壁温计算...............................................................................................233.7实例锅炉介绍...............................................................................................253.8实例应用计算结果.............................................