题目:过热蒸汽温度控制系统设计摘要过热蒸汽温度控制系统是单元机组不可缺少的重要组成部分,其性能和可靠性已成为保证单元机组安全性和经济性的重要因素。过热蒸汽温度较高时,机组热效率则相对较高,但过高时,汽机的金属材料又无法承受,气温过低则影响机组效率。过热蒸汽温度的稳定对机组的安全经济运行非常重要,所以对其控制有较高的要求。但是由于过热蒸汽温度是一个典型的大迟延、大惯性、非线性和时变性的复杂系统,本次设计采用串级控制以提高系统的控制性能,在系统中采用了主控-串级控制的切换装置,使系统可以适用于不同的工作环境。通过使用该系统,可以使得锅炉过热器出口蒸汽温度在允许的范围内变化,并保护过热器营壁温度不超过允许的工作温度。关键词:过热蒸汽温度,减温水,串级控制系统,PIDABSTRACTThesuperheatedsteamtemperaturecontrolsystemisanimportantandindispensableunitaircrewpart,itsperformanceandreliabilityhasbecomeensuresafetyandeconomicbehavioroftheunitaircrewimportantfactors.Thesuperheatedsteamtemperatureishigher,thethermalefficiencyisrelativelyhigh,butishigh,themetalmaterialsandtheturbineunabletobear,thetemperatureistoolowwillinfluencetheunitefficiency.Thesuperheatedsteamtemperaturestabilityoftheunitsafeandeconomicoperationisveryimportant,soforthecontrolhavehigherrequirements.Butbecausethesuperheatedsteamtemperatureisatypicaltime-delayed,largeinertia,nonlinearandchangeablecomplexsystem,thisdesignUSESthecascadecontrolinordertoimprovethecontrolperformanceofthesystem,inthesystembythemaster-cascadecontrolofswitchingdevice,makethesystemcanbeusedindifferentworkingenvironment.Byusingthissystem,canmaketheboileroverheatingexportsteamtemperatureinallowedwithinthescopeofthechange,andtheprotectionofsuperheaterwalltemperaturenotmorethanallowthecampofworkingtemperature.Keywords:thesuperheatedsteamtemperature,reducewarmwater,cascadecontrolsystem,PID目录摘要....................................................................IABSTRACT...............................................................II1绪论..................................................................11.1选题的背景及其意义...............................................11.2国内外研究现状...................................................11.3本次设计的目的...................................................21.4本次设计所做的工作...............................................22汽温控制系统的组成与对象动态特性......................................42.1汽温调节的概念和方法.............................................42.1.1从蒸汽侧调节汽温...........................................42.1.2从烟气侧调节汽温...........................................52.2过热器的分类及基本结构...........................................72.2.1过热器的分类...............................................72.2.2过热器的基本结构...........................................92.3过热蒸汽温度控制系统的基本结构与工作原理........................112.3.1过热器一级减温控制系统....................................112.3.2二级减温控制系统..........................................122.4过热蒸汽温度控制对象的动静态特性................................142.4.1静态特性..................................................142.4.2动态特性..................................................143过热汽温控制系统的基本方案...........................................183.1串级汽温控制系统................................................183.2串级汽温控制系统的基本结构及原理................................183.3串级汽温控制...