涡街流量计的空气标定和蒸汽实流测试对比分析  

Comparative Analysis of Air Calibration and Steam Flow Test of Vortex Shedding Flowmeter

作　　者：顾永伟 苏黎丽 陈躬炎 李人东 GU Yongwei;SU Lili;CHEN Gongyan;LI Rendong(ABB Engineering(Shanghai)Ltd.,Shanghai 201319,China;Fujian Metrology Institute,Fuzhou 350003,China;National Supervision and Inspection Center for Steam Flow Meter,Fuzhou 350309,China)

机构地区：[1]上海ABB工程有限公司,上海201319 [2]福建计量科学研究院,福建福州350003 [3]国家蒸汽流量计产品质量监督检验中心,福建福州350309

出　　处：《自动化仪表》2019年第12期72-75,79,共5页Process Automation Instrumentation

摘　　要：有文献指出,空气与蒸汽流量在涡街流量计上的对比误差高达7.8%。从动力学相似的角度,澄清了用空气代替水蒸气进行标定的理论依据。涡街流量计对不同被检介质有较广泛的适应性,较大的误差一方面来源于介质、产品设计的鲁棒性不够、对关键参数的质量控制不到位等因素;另一方面源于过去的蒸汽应用不丰富,经常依靠化工算图及模型的手段来估算蒸汽的黏度和密度。这种估算存在化工知识、物理模型以及复杂的单位制转换这三大难点,不易推广。利用在线计算器,可以快速、准确地获取蒸汽的状态数据,并用算例加以说明。将空气标定的涡街流量计在蒸汽装置上进行实流测试,得出流量对比误差可以控制在2.5%以内。It was reported that the difference of inaccuracy between air and steam flow measurements with vortex shedding flowmeter could reach as large as 7.8%.From the view of hydrodynamic similitude,the validity of using air instead of steam as calibration medium was clarified in this paper.Vortex shedding flowmeter has good adaptability to various measured fluids.It is more likely that the larger error stems from the factors such as the poor robustness of the design of the product,or insufficient quality control of the key parameters,rather than medium.On the other hand,due to less application data on steam in the past,steam data were often estimated by means of nomograms and models.Such kind of estimation was difficult to generalize because of the three difficulties of chemical engineering knowledge,physical model,and complex unit system conversion.In view of the above problems,an online calculator was proposed to obtain the state data of steam quickly and accurately,which was illustrated with examples.Steam flow test conducted on the vortex flowmeter calibrated with air showed that the comparative error could be controlled within 2.5%.

关 键 词：涡街流量计 蒸汽计量 过热蒸汽 实流测试 空气标定 流体动力学 饱和蒸汽 

分 类 号：TH814[机械工程—仪器科学与技术]