基于雷诺数对涡轮流量计计量特性的研究

发布时间：2018-10-13 10:30

【摘要】：由于响应速度快、测量精度高、量程宽等优点,国内外普遍采用涡轮流量计作为工作级标准表,用于贸易交接或对其他流量计进行量值传递。涡轮流量计的使用存在定点使用与非定点使用两种情况,国内已有研究基本局限在1个大气压,这直接影响着非定点使用时涡轮流量计使用的准确性、可靠性。因此,本论文基于雷诺数对涡轮流量计计量特性开展系统研究。中国计量科学研究院于2014年底建成一套高压气体流量标准装置,包括高压pVTt气体流量原级标准装置、高压音速喷嘴法气体流量次级标准装置及高压环道气体流量工作标准装置。本文以高压环道气体流量标准装置为主要实验平台,以1台Dn 100涡轮流量计作为被检流量计对高压环道装置的性能进行研究,结果表明:以4台涡轮流量计作为标准表的高压环道气体流量标准装置,可实现最大压力2.5 MPa、最大流量1600 m~3/h的测量能力,扩展不确定度为0.21%(k=2)。基于高压环道气体流量标准装置性能水平,本文就雷诺数对涡轮流量计误差特性曲线进行研究,结果发现:1)使用NIM-2014模型,在临界雷诺数以下涡轮流量计误差特性曲线会出现明显离散,且其离散程度随着压力、流量的降低而增强。2)基于新的轴承摩擦阻力矩模型,本文提出NIM-2015模型。3)相比NIM-2014模型,NIM-2015模型可将4台涡轮流量计标准表非定点使用时的不确定度由(0.35%~0.42%)(k=2)下降至(0.22%~0.25%)(k=2)。此外,采用3台被检表对作为标准表的涡轮流量计间的一致性进行验证,结果表明:NIM-2015模型可以对作为非定点使用时涡轮流量计的计量特性予以准确评估。
[Abstract]:Because of the advantages of high response speed, high measurement precision and wide measuring range, turbine Flowmeter is widely used as the working class standard table at home and abroad, which can be used to trade or transfer the value of other Flowmeters. The use of turbine Flowmeter has two situations: fixed-point use and non-fixed-point use. Domestic research has been basically limited to one atmospheric pressure, which directly affects the accuracy and reliability of turbine Flowmeter when non-fixed-point use. Therefore, based on Reynolds number, the measurement characteristics of turbine Flowmeter are studied systematically in this paper. At the end of 2014, China Institute of Metrology completed a set of high pressure gas flow standard equipment, including high pressure pVTt gas flow standard device, high pressure sonic nozzle method gas flow secondary standard device and high pressure loop gas flow working standard device. In this paper, a Dn 100 turbine Flowmeter is used as the measured Flowmeter to study the performance of the high pressure annular device based on the high pressure annular gas flow standard device as the main experimental platform. The results show that the high pressure annular gas flow standard device with four turbine Flowmeters as the standard table can realize the measurement capability of the maximum pressure 2.5 MPa, and the maximum flow rate of 1600 mm3 / h, and the extended uncertainty is 0.21% (km2). Based on the performance level of high pressure annular gas flow standard device, the error characteristic curve of Reynolds number to turbine Flowmeter is studied in this paper. The results are as follows: 1) using NIM-2014 model, The error characteristic curve of turbine Flowmeter below critical Reynolds number will appear obvious discretization, and its dispersion degree will increase with the decrease of pressure and flow rate. 2) based on the new friction resistance moment model of bearing, In this paper, NIM-2015 model .3) compared with NIM-2014 model, NIM-2015 model can reduce the uncertainty of 4 turbine Flowmeter standard meters from (0.35 ~ 0. 42%) (KG ~ 2) to (0.22 ~ 0. 25%) (KT ~ 2). In addition, the consistency of turbine Flowmeter as a standard meter is verified by three check tables. The results show that the NIM-2015 model can accurately evaluate the metering characteristics of turbine Flowmeter when it is used as a non-fixed point.
【学位授予单位】：中国计量学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH814

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