Design method for flow tube structure of electromagnetic water meter with shrunk measurement tube based on pressure loss-flow restriction. (August 2020)

• Record Type: Journal Article
• Authors: Liang, Li-Ping; Ge, Yu-Shi; Xu, Ke-Jun; Huang, Yun-Zhi; Yang, Shuang-Long; Xu, Wei; Wu, Jian-Ping; Qi, Fei-Yan
• Is Part Of: Flow measurement and instrumentation. Volume 74(2020)
• Publication Date: 2020-08
• Subjects: Electromagnetic water meter -- Shrunk tube -- Structural design method; Fluid dynamic measurements -- Periodicals; Flow meters -- Periodicals; Fluides, Dynamique des -- Mesure -- Périodiques; Débitmètres -- Périodiques; 681.2805
• DOI: 10.1016/j.flowmeasinst.2020.101778
• Languages: English
• ISSNs: 0955-5986

Abstract

Abstract: Due to the low flow rate measurement demand for battery-powered electromagnetic water meter, shrunk measurement tubes (such as circular section transition to square section) are often used to enhance flow velocity and measurement performance at small flow rate. However, this will also result in an increase in sensor pressure loss, even exceeding the pressure loss limit. Therefore, it is necessary to study a flow tube structure design method based on pressure loss-flow restriction, and design a flow tube structure which can not only maximize the induced voltage, but also meet the actual pressure loss requirement. Because there are many unknown variables in the formula of pressure loss mechanism, it cannot be directly used in structural design. Therefore, taking DN100 sensor as an example, based on finite element software, the variation of pressure loss with the length, width and height of rectangular section is obtained by orthogonal test method, and the numerical model of pressure loss is established. According to the requirements of industry and induced voltage enhancement, the optimal rectangular section size is found with the established pressure loss numerical model, and the structure of flow tube transition section is further optimized to reduce pressure loss. Finally, the prototype is made according to the optimized structure. Pressure loss experiment shows that the error between simulated value and measured value is within ±2.68% (±0.4 KPa). It means the pressure loss-flow restriction based design method for flow tube structure of electromagnetic water meter with shrunk measurement tube is effective and reliable. Highlights: A new pressure loss-flow restriction based sensor structure design method is proposed in this paper, aiming at improving induced voltage for electromagnetic water meter with rectangular shrunk measurement tube. A numerical model of pressure loss and flow tube structure parameters is established, which can be used to guide practical production under different pressure loss-flow restriction. A prototype is made. The pressure loss experiment results prove the reliability of the proposed method.