海上晃动对FLNG再沸器液面波动的影响
|
摘要
在浮式液化天然气船(FLNG)的天然气处理工艺中,含有酸性气体的富胺液进入再生塔内解吸,再沸器位于再生塔塔底,为富胺液的解吸过程提供热量。使用ANSYS内嵌模块Geometry建立再沸器的三维物理模型,再沸器主要由外壳、加热装置和溢流堰组成,只研究晃动对液面波动的影响,所以未设置加热介质和胺液的进出口。将再沸器设置为一个封闭的装置,内部仅有水和水蒸气2种介质。使用ANSYS内嵌模块Mesh进行网格划分,网格类型选择非结构网格,对再沸器模型进行网格独立性检验,网格数量取3 891 653,网格最大尺寸为3 mm。为实现模拟过程的晃动,编写晃动角速度、晃动线速度的UDF函数,导入到Fluent软件中。分别对横摇、纵摇、艏摇、横荡、纵荡、垂荡6种单自由度晃动和横摇8°+纵摇8°、横摇8°+艏摇8°、横摇8°+横荡150 mm、横摇8°+纵荡150 mm、横摇8°+垂荡150 mm这5种两自由度耦合晃动工况下,初始时刻与晃动至0. 25倍晃动周期时的再沸器液面波动情况进行模拟。得出结论:在单自由度晃动工况下,横摇对再沸器的性能影响最大,纵摇、艏摇、垂荡、横荡、纵荡对再沸器的性能影响很小。在耦合晃动工况中,横摇对液面波动起主导作用,对再沸器的性能影响较大;横摇8°+横荡150 mm、横摇8°+纵荡150 mm、横摇8°+垂荡150 mm这3种耦合工况下的液面波动与横摇工况相比更大。在FLNG再沸器的设计和安装过程中,应充分考虑横摇晃动工况以及以横摇晃动为主的耦合晃动工况。
In the natural gas treatment process of a floating liquefied natural gas( FLNG) vessel,the rich amine liquid containing acid gas is desorbed into the regeneration tower,and the reboiler is located at the bottom of the regeneration tower to provide heat for the desorption process of the rich amine liquid. The ANSYS embedded module Geometry is used to establish the three-dimensional physical model of the reboiler. The reboiler is mainly composed of the outer casing,the heating device and the overflow weir. The influence of the swaying on the fluctuation of the liquid level is only studied,so the inlet and outlet of the heating medium and the amine liquid are not set. The reboiler is set as a closed device with only two media,water and water vapor inside. The ANSYS embedded module Mesh is used to divide the grid,the grid type is selected unstructured grid,and the grid independence of the reboiler model is tested. The number of grid is 3 891 653. The maximum grid size is 3 mm. In order to achieve the swaying of the simulation process,UDF functions for swaying angular velocity and swaying linear velocity are programmed and imported into the Fluent software. Under the conditions of 6 kinds of single degrees of freedom swaying,such as rolling,pitching,yawing,swaying,surging and heaving,and five kinds of two-degree-of-freedom coupling swaying,such as rolling 8° + pitching 8°,rolling 8° + yawing 8°,rolling 8° + swaying 150 mm,rolling 8° +surging 150 mm and rolling 8° + heaving 150 mm,the fluctuations of the liquid level in the reboiler at the initial time and the swaying to 0. 25 times the swaying cycle are simulated. It is concluded that under the singledegree-of-freedom swaying conditions,the rolling has the greatest influence on the performance of the reboiler.The pitching,yawing,heaving,swaying and surging have little effect on the performance of the reboiler. Under the two-degree-of-freedom coupling swaying condition,the rolling has a dominant effect on the fluctuation of the liquid level,which has the greater influence on the performance of the reboiler. The fluctuations of the liquid level under the three coupling conditions of rolling8° + swaying 150 mm,rolling 8° + surging 50 mm and rolling 8° + heaving 150 mm are greater than those under the rolling condition. In the design and installation of the FLNG reboiler,the rolling swaying conditions and the coupling swaying conditions based on the rolling should be fully considered.
In the natural gas treatment process of a floating liquefied natural gas( FLNG) vessel,the rich amine liquid containing acid gas is desorbed into the regeneration tower,and the reboiler is located at the bottom of the regeneration tower to provide heat for the desorption process of the rich amine liquid. The ANSYS embedded module Geometry is used to establish the three-dimensional physical model of the reboiler. The reboiler is mainly composed of the outer casing,the heating device and the overflow weir. The influence of the swaying on the fluctuation of the liquid level is only studied,so the inlet and outlet of the heating medium and the amine liquid are not set. The reboiler is set as a closed device with only two media,water and water vapor inside. The ANSYS embedded module Mesh is used to divide the grid,the grid type is selected unstructured grid,and the grid independence of the reboiler model is tested. The number of grid is 3 891 653. The maximum grid size is 3 mm. In order to achieve the swaying of the simulation process,UDF functions for swaying angular velocity and swaying linear velocity are programmed and imported into the Fluent software. Under the conditions of 6 kinds of single degrees of freedom swaying,such as rolling,pitching,yawing,swaying,surging and heaving,and five kinds of two-degree-of-freedom coupling swaying,such as rolling 8° + pitching 8°,rolling 8° + yawing 8°,rolling 8° + swaying 150 mm,rolling 8° +surging 150 mm and rolling 8° + heaving 150 mm,the fluctuations of the liquid level in the reboiler at the initial time and the swaying to 0. 25 times the swaying cycle are simulated. It is concluded that under the singledegree-of-freedom swaying conditions,the rolling has the greatest influence on the performance of the reboiler.The pitching,yawing,heaving,swaying and surging have little effect on the performance of the reboiler. Under the two-degree-of-freedom coupling swaying condition,the rolling has a dominant effect on the fluctuation of the liquid level,which has the greater influence on the performance of the reboiler. The fluctuations of the liquid level under the three coupling conditions of rolling8° + swaying 150 mm,rolling 8° + surging 50 mm and rolling 8° + heaving 150 mm are greater than those under the rolling condition. In the design and installation of the FLNG reboiler,the rolling swaying conditions and the coupling swaying conditions based on the rolling should be fully considered.
引文
[1]颜映霄,徐正斌,王世清.国内外海上油田油气集输及配套技术现状和发展趋势浅析[J].中国海洋平台,2002(2):9-12.
[2]唐建峰,金新明,周军逸,等.FLNG填料塔内气体分布器适应性试验[J].油气储运,2018,37(7):822-830.
[3]夏丹,郑云萍,李剑峰,等.浮式液化天然气技术综述[J].天然气与石油,2013,31(3):9-13.
[4]李瑛玉.MDEA溶剂再生塔再沸器的正确选择及安装[J].价值工程,2014,33(10):41-42.
[5]丰存礼,刘成,李永辉,等.双切环流气体分布器内流场FLUENT数值模拟[J].石油化工设备,2004,33(2):25-27.
[6]陈杰,唐建峰,金新明,等.醇胺法脱碳工艺参数中试实验与模拟优化[J].石油学报(石油加工),2017,33(5):966-974.
[7]刘明亮,张思青,李胜男.网格对CFD模拟结果的影响分析[J].水电与抽水蓄能,2016,2(4):41-47.
[8]黄彬.基于晃动工况的填料吸收塔脱酸性能研究(硕士学位论文)[D].青岛:中国石油大学(华东),2016:37-38.
[2]唐建峰,金新明,周军逸,等.FLNG填料塔内气体分布器适应性试验[J].油气储运,2018,37(7):822-830.
[3]夏丹,郑云萍,李剑峰,等.浮式液化天然气技术综述[J].天然气与石油,2013,31(3):9-13.
[4]李瑛玉.MDEA溶剂再生塔再沸器的正确选择及安装[J].价值工程,2014,33(10):41-42.
[5]丰存礼,刘成,李永辉,等.双切环流气体分布器内流场FLUENT数值模拟[J].石油化工设备,2004,33(2):25-27.
[6]陈杰,唐建峰,金新明,等.醇胺法脱碳工艺参数中试实验与模拟优化[J].石油学报(石油加工),2017,33(5):966-974.
[7]刘明亮,张思青,李胜男.网格对CFD模拟结果的影响分析[J].水电与抽水蓄能,2016,2(4):41-47.
[8]黄彬.基于晃动工况的填料吸收塔脱酸性能研究(硕士学位论文)[D].青岛:中国石油大学(华东),2016:37-38.