卧式热虹吸再沸器出口管线振动分析及改造
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摘要
热虹吸再沸器的详细工程设计影响石油化工装置的稳定运行,一台完整的热虹吸再沸器的工艺设计包括结构设计、压力平衡计算和流型稳定性分析。某MTO装置开工过程中一台进料汽化器的出口管线发生振动,从而影响装置开车。为解决此问题,借助传热设计软件HTRI7.0对该换热器进行分析和改造:卧式热虹吸再沸器的安装高度与再沸器的出口汽化率(或者说流型)紧密相关;卧式热虹吸再沸器的出口管线较长,管线布置要求较多,对于再沸器的流型影响较大,在工艺系统和结构设计过程中应仔细核算;与自然循环的再沸器相连的塔器设备的液位对再沸器的安装高度有影响,在进行结构设计过程中,应注意消除软件给出的所有不稳定性或振动的警告。发现再沸器的震动原因为推动力太大,导致再沸器出口管线两相流流体的流型为块状流从而引起塔器不稳定运行,可以在再沸器的入口管线增加手动调节阀调节推动力。
The detailed engineering design of thermosiphon reboiler is important for the stable operation of petrochemical plant,and the process design of a complete thermosiphon reboiler includes structural design,pressure equilibrium calculation and two phase flow pattern analysis.During the start-up of a MTO unit,the outlet pipeline of a feed evaporator vibrated,affecting the startup of the unit.To solve this problem,software HTRI7.0 is used to analyze and revamp this horizontal thermosiphon reboiler.The installation height of horizontal thermosiphon reboiler is closely related to the outlet vaporization rate(or flow pattern) of the reboiler.The outlet pipeline of horizontal thermosiphon reboiler is long and there are many requirements for piping layout.This has great influence on the flow pattern of the reboiler,so careful calculation is needed in the design of process system and structure.The level of tower equipment connected with natural circulation reboiler influences the installation height of the reboiler,so warnings of instability or vibration given by the software should be eliminated during the structural design.It is found that the reason for the vibration of reboiler is the high liquid static head for natural recirculation,which leads to the churn flow of the two phase flow in outlet pipeline and results in the unstable operation of the tower.A manual control valve may be added in the inlet pipeline of the reboiler to reduce the liquid head.
The detailed engineering design of thermosiphon reboiler is important for the stable operation of petrochemical plant,and the process design of a complete thermosiphon reboiler includes structural design,pressure equilibrium calculation and two phase flow pattern analysis.During the start-up of a MTO unit,the outlet pipeline of a feed evaporator vibrated,affecting the startup of the unit.To solve this problem,software HTRI7.0 is used to analyze and revamp this horizontal thermosiphon reboiler.The installation height of horizontal thermosiphon reboiler is closely related to the outlet vaporization rate(or flow pattern) of the reboiler.The outlet pipeline of horizontal thermosiphon reboiler is long and there are many requirements for piping layout.This has great influence on the flow pattern of the reboiler,so careful calculation is needed in the design of process system and structure.The level of tower equipment connected with natural circulation reboiler influences the installation height of the reboiler,so warnings of instability or vibration given by the software should be eliminated during the structural design.It is found that the reason for the vibration of reboiler is the high liquid static head for natural recirculation,which leads to the churn flow of the two phase flow in outlet pipeline and results in the unstable operation of the tower.A manual control valve may be added in the inlet pipeline of the reboiler to reduce the liquid head.
引文
[1]刘巍.冷换设备工艺计算手册[M].2版.北京:中国石化出版社,2008.
[2]DON LOVE.Nohassle Reboiler Selection[J].Hydrocarbon Process,1992,10:41-43.
[3]施林德尔.换热器的热设计与流动设计:第三卷[M].北京:机械工业出版社,1988:160-163.
[4]张朝环.热虹吸式再沸器的压力平衡设计[J].化工进展,2015(34):43-46.
[5]胡景辉,张芳军,李雨,等.基于压力平衡下的立式热虹吸再沸器安装高度设计[J].河南化工,2017(34):42-45.
[6]刘清玉.两相流管线振动分析[J].石油化工设计,2011,18(1):25-27.
[7]尾花英朗.热交换器设计手册:上册[M].北京:石油工业出版社,1981.
[8]施林德尔.换热器的热设计与流动设计:第二卷[M].北京:机械工业出版社,1988.
[9]孟飞.管线中水击现象的成因及预防措施[J].化工管理,2016(5):203-205.
[10]刘成军,王端明.热虹吸重沸器的选用和配管[J].炼油设计,1999,29(4):9-22.
[11]王嫦娥.浅谈塔底再沸器的两种工艺及管道设计要点[J].工业技术,2012,31:61.
[12]刘成军.热虹吸重沸器循环回路的设计探讨[J].化工设计,2008,18(6):2.
[2]DON LOVE.Nohassle Reboiler Selection[J].Hydrocarbon Process,1992,10:41-43.
[3]施林德尔.换热器的热设计与流动设计:第三卷[M].北京:机械工业出版社,1988:160-163.
[4]张朝环.热虹吸式再沸器的压力平衡设计[J].化工进展,2015(34):43-46.
[5]胡景辉,张芳军,李雨,等.基于压力平衡下的立式热虹吸再沸器安装高度设计[J].河南化工,2017(34):42-45.
[6]刘清玉.两相流管线振动分析[J].石油化工设计,2011,18(1):25-27.
[7]尾花英朗.热交换器设计手册:上册[M].北京:石油工业出版社,1981.
[8]施林德尔.换热器的热设计与流动设计:第二卷[M].北京:机械工业出版社,1988.
[9]孟飞.管线中水击现象的成因及预防措施[J].化工管理,2016(5):203-205.
[10]刘成军,王端明.热虹吸重沸器的选用和配管[J].炼油设计,1999,29(4):9-22.
[11]王嫦娥.浅谈塔底再沸器的两种工艺及管道设计要点[J].工业技术,2012,31:61.
[12]刘成军.热虹吸重沸器循环回路的设计探讨[J].化工设计,2008,18(6):2.