Research On The Intelligent Flow Totalizer Of V-cone Flowmeter And Its Remote Operating Platform For Management Software

Differential pressure flowmeter is the most widely used flowmeter in the industry, such as petroleum, natural gas, and chemical field. As a new type of differential pressure flowmeter, V-cone flowmeter has many advantages. Compared with the traditional orifice plate flowmeter, V-cone has lower permanent pressure loss, less straight pipe requirement for upstream and downstream, and dirty-resistance, etc. It is especially suitable for some special situations, such as the measurement of wet gas in near shore oil field, rubbish burning for power, coke oven gas's measurement and so on. Since V-cone flowmeter has those features, it has aroused much attention in China and throughout the world in the recent few years. The same as any other primary throttling device, it is compulsory to use a high-quality intelligent flow totalizer to obtain an excellent overall system performance. Therefore, it is necessary to make researches on this issue.In view of the features of V-cone flowmeter, this research designs an intelligent flow totalizer and a remote operating platform for the management software. Based on the principle of high accuracy, low power consumption, integration and intelligence, this research mainly includes the following tasks: comparison among different fluid media density compensation models, developing the intelligent flow totalizer, and the design of the remote operating platform for the management software.Firstly, a flow calculation formula is defined in accordance with the measurement principle of the V-cone flowmeter. A contrastive study dealt with the density compensation models of different fluid media during the actual measurement. As for the steam flow, a brand-new IAPWS-IF97 formula is adopted to provide density compensation, which overcomes the application deficiencies of the traditional steam density compensation method in large work span of situation variations or satisfying the accuracy requirements.Secondly, an intelligent flow totalizer with MSP430F149 SCM as the core control is designed according to the functional requirements. Based on the principle of low power consumption and integrity, the hardware of the totalizer adopts 12-bit A/D converter in the SMC, low power consumption LCD display, and real-time clock chip; using the message-driven and modular programming idea, the software develops a high-accuracy flow measurement and compensation program. Finally, a remote operating platform for the management software of the intelligent flow totalizer is developed by utilizing the self-programming capability of SCM, which realizes the remote meter upgrade and broadens its application and functions.The experiment of the prototype shows that, the intelligent flow totalizer, has higher measurement accuracy, in the common range of industry, the average relative error of density of saturated steam is 0.05% and that of overheated steam is 0.08%, the average relative error in flow measurement of the totalizer is 0.39%.