超声波流量计整流器设计及验证
|
摘要
针对时差法超声波流量计的测量准确度受管道条件影响较大的问题,采用在流量计前端加装整流器的方法,以减少因弯管等阻流件导致管道内出现的二次流、涡流等现象,从而满足计量准确度的要求。整流器由风扇式叶片、直管混合区和多孔管段三部分组成,风扇式叶片分别设计为8片、10片和12片三种形式。通过计算流体力学(CFD)数值仿真对管道内流速分布形态和线速度分布的一致性进行分析。仿真结果表明,整流器叶片数为12片时整流效果最佳。采用标准流量计法流量标准装置,对12片叶片的整流器的整流效果进行试验验证。试验结果表明:12片叶片的整流器不仅可以满足超声波流量计的测量准确度,而且可以缩短上游弯管与超声波流量计之间的直管段距离。超声波流量计在工商业等天然气运输管道中的应用具有明显的优势。
Due to the measurement accuracy of time-difference method ultrasonic flowmeter is greatly affected by pipeline conditions,by using the method of installing a rectifier at the front end of the flowmeter to reduce secondary flow,eddy current,etc.,in the pipeline which are caused by the obstruction parts such as elbows,so as the requirement of measurement accuracy can be met. The rectifier consists of three parts,fan blades,straight pipe mixing area and porous pipe sections; while the fan blades are designed in eight,ten,and twelve,three forms respectively. Through the computational fluid dynamic( CFD) numerical simulation,the consistency of the flow velocity distribution in the pipeline and the velocity distribution is analyzed,The simulation result shows that when the number of the blades is twelve,the rectification effect is the best. The experimental results of standard flow meter method flow standard device verify that the rectifier with twelve blades has good rectification effect. It can shorten the distance of the straight pipe between the elbow and the ultrasonic flowmeter,and improve the measurement accuracy. It provides obvious advantages for ultrasonic flowmeter to be used in industrial and other natural gas transportation pipeline applications.
Due to the measurement accuracy of time-difference method ultrasonic flowmeter is greatly affected by pipeline conditions,by using the method of installing a rectifier at the front end of the flowmeter to reduce secondary flow,eddy current,etc.,in the pipeline which are caused by the obstruction parts such as elbows,so as the requirement of measurement accuracy can be met. The rectifier consists of three parts,fan blades,straight pipe mixing area and porous pipe sections; while the fan blades are designed in eight,ten,and twelve,three forms respectively. Through the computational fluid dynamic( CFD) numerical simulation,the consistency of the flow velocity distribution in the pipeline and the velocity distribution is analyzed,The simulation result shows that when the number of the blades is twelve,the rectification effect is the best. The experimental results of standard flow meter method flow standard device verify that the rectifier with twelve blades has good rectification effect. It can shorten the distance of the straight pipe between the elbow and the ultrasonic flowmeter,and improve the measurement accuracy. It provides obvious advantages for ultrasonic flowmeter to be used in industrial and other natural gas transportation pipeline applications.
引文
[1]吴斌,赵刚.浅谈超声波流量计的分类和实际应用[J].现代计量仪器与技术,2006(5):21-24.
[2]张志.浅析超声波流量计的应用[J].科技情报开发与经济,2008,18(33):211.
[3]YEH T T,ESPINA P I.Special ultrasonic flowmeters for in-situ diagnosis of swirl and cross flow[C]//Proceedings of ASME FEDSM 2001,New Orleans,Louisiana,2011:110-112.
[4]王雪峰.基于时差法气体超声波流量计的关键技术研究[D].大连:大连理工大学,2011.
[5]强发红,毛协柱.时差法超声流量计的应用技术[J].石油化工自动化,2001(5):60-64.
[6]兰纯纯.时差法超声波流量计的研究[D].重庆:重庆大学,2006.
[7]LYNNWORTH L C.Ultrasonic measurements for process control:theory,techniques,applications[M].Pittsburgh:Academic Press,2013.
[8]梁国伟,蔡武昌.流量测量技术及仪表[M].北京:机械工业出版社,2005:292-296.
[9]杨鸣,金定飞,徐永鹏,等.超声波流量计的整流器的设计方法105444828 A[P].
[10]陈红.上游单弯管对超声波流量计测量误差的影响[D].杭州:中国计量学院,2014.
[2]张志.浅析超声波流量计的应用[J].科技情报开发与经济,2008,18(33):211.
[3]YEH T T,ESPINA P I.Special ultrasonic flowmeters for in-situ diagnosis of swirl and cross flow[C]//Proceedings of ASME FEDSM 2001,New Orleans,Louisiana,2011:110-112.
[4]王雪峰.基于时差法气体超声波流量计的关键技术研究[D].大连:大连理工大学,2011.
[5]强发红,毛协柱.时差法超声流量计的应用技术[J].石油化工自动化,2001(5):60-64.
[6]兰纯纯.时差法超声波流量计的研究[D].重庆:重庆大学,2006.
[7]LYNNWORTH L C.Ultrasonic measurements for process control:theory,techniques,applications[M].Pittsburgh:Academic Press,2013.
[8]梁国伟,蔡武昌.流量测量技术及仪表[M].北京:机械工业出版社,2005:292-296.
[9]杨鸣,金定飞,徐永鹏,等.超声波流量计的整流器的设计方法105444828 A[P].
[10]陈红.上游单弯管对超声波流量计测量误差的影响[D].杭州:中国计量学院,2014.