共查询到19条相似文献,搜索用时 78 毫秒
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《中国计量》2004,(9):77-77
读者问:“在最新公布的ISO5167:2003(E)国际标准中,对孔板和文丘里管上游所要求的最小直管段长度都提出了全新的要求。我厂使用孔板很多,按照新的国际标准要求,这些孔板流量计的上游直管段长度都不合格,应该怎么办?”孙教授:国际标准ISO5167:2003中所要求的上游最小直管段长度与流量计的类型、直径比(β值)和上游阻流件的类型有关。由于新标准对孔板和文丘里管上游最小直管段长度提出了加长的要求,在许多实际使用场合确实很难满足。现将可供选用的解决办法分述如下:(一)国际标准ISO5167:2003(E)推荐采用流动调整器(FC)。在一个给定的… 相似文献
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国际标准ISO5167:2003(E)的主要变化及应采取的应对办法 总被引:1,自引:0,他引:1
以孔板、喷嘴和文丘里管为代表的差压式流量计应用于工业已愈百年。由国家技术监督局于1993年发布实施的国家标准GB/T2624-1993《流量测量节流装置,用孔板、喷嘴和文丘里管测量充满圆管的流体流量》就是等效采用了当时的国际标准。国际上经过10多年的大量实验研究与总结,已于2003年3月由国际标准化组织(ISO)正式公布了最新的国际标准ISO5167:2003(E)。因最新国际标准有许多实质性的变化,本刊特邀请北京化工大学的孙延祚教授撰文介绍。读者如有疑问可与孙教授直接联系,联系方式附后? 相似文献
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本刊2008年第3期发表了题名为“均速管流量计的校验与误差分析”一文,文章作者摘抄引用了计量出版社1984年出版的《均速管流量计》一书中的内容,该书作者即我国流量专家毛新业老师看了这篇文章后认为有些观点随着科学技术的进步需要更新。他特为本刊撰文,对均速管流量计的校验与误差分析提出了一些新的观点,以供读者参考,期望对选用均速管流量计的用户有一些帮助。 相似文献
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简要阐述了活塞式液体体积管的工作原理,详细推导了确定被检流量计的流量计系数、基本误差及压力、温度修正系数的计算公式,分析了流量计系数近似计算公式所产生的计算误差,并对影响活塞式液体体积管与流量计检定性能的若干问题提出了改进建议。 相似文献
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The operation of a magnetic flowmeter for conductive fluids is analyzed and the magnetic, and electric fields in it are described as solutions of boundary value problems. Finite-element methods are utilized to solve the problems, and solutions are presented for a variety of flow profiles and inner tube conductivities. The method gives an insight into both the phenomenon involved and the effects of the geometry and the material characteristics on the accuracy and sensitivity of the flowmeter 相似文献
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The absorption of SO2 and NH3 from the flue gas into NaOH and H2SO4 solutions, respectively has been studied using an industrial scale ejector–venturi scrubber. A statistical methodology is presented to characterise the performance of the scrubber by varying several factors such as gas pollutant concentration, air flowrate and absorbing solution flowrate. Some types of venturi tube constructions were assessed, including the use of a two-stage venturi tube.
The results showed a strong influence of the liquid scrubbing flowrate on pollutant removal efficiency. The initial pollutant concentration and the gas flowrate had a slight influence. The use of a two-stage venturi tube considerably improved the absorption efficiency, although it increased energy consumption.
The results of this study will be applicable to the optimal design of venturi-based absorbers for gaseous pollution control or chemical reactors. 相似文献
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小管径频差法超声波流量计的测量精度受各种因素的影响,因而获得较高精度比较困难。本文对影响小管径频差法超声波流量计测量精度的多种因素进行数理分析。在此基础上结合多年研制该流量计的实际经验,提出提高测量精度的措施及其方法。 相似文献
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不同介质对质量流量计的校准误差影响 总被引:1,自引:0,他引:1
随着科里奥利质量流量计广泛地运用到CNG加气机中,其计量的准确性越来越受到关注。通过运用目前最流行的有限元(FEM)软件ANSYS对管道内流体速度场进行仿真,观察到在相同质量流量下,不同介质在测量管道内具有不同的流体行为,并定性地分析了气体介质的速度场非对称特性对质量流量计校准误差的影响,最后提出了解决方案和建议。 相似文献
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In this paper, the author investigates theoretically the magnitudes of the zero offsets and the zero drifts originating from magnetic-flux linkage between the coils of the electromagnet and the loop formed by the electrode cables in an electromagnetic flowmeter for electrolytic conductors. The dependence of such zero offsets on the liquid properties, frequency of operation, etc., is explained. This dependence is used to predict the zero offsets expected in metering this liquid using phase-sensitive detection with the flowmeter tube described in this paper. Precautions needed in flowmeter design to minimize instrument offsets and zero drifts are explained. In the end, the proposed model was validated against the experimental data 相似文献