On the influence of gas flow velocity on the accuracy of an ultrasonic flow meter

The article discusses the principles of operation of an ultrasonic flow meter in a wide range of gas flow rates. In modern industry, especially in gas supply, the accuracy of accounting for the flow of gas transported through gas pipelines is more important than anywhere else. A seemingly small error in measuring gas consumption can ultimately cause large financial losses in gas supplies and sales. To measure gas flow, ultrasonic flow meters are currently becoming increasingly popular. Having no mechanically moving or gas-dynamically loaded structural elements in the flow, such flow meters are reliable, durable, easy to maintain and allow one to calculate volumetric and mass flow rates in commercial gas metering with an accuracy acceptable for industry. Using computational gas dynamics methods using three-dimensional computer modeling, studies of the flow of methane gas in a circular channel were carried out. A comparative analysis of the influence of gas flow velocity on the accuracy of ultrasonic flow meter readings was carried out. The influence of different measurement schemes on flow velocity measurement was studied. The influence of the shape of the flow profile on the accuracy of the flow meter is shown. Graphical dependences of the velocities on the flowmeter beams on the average flow velocity were constructed. It is shown that the magnitude of the flowmeter error decreases with increasing flow velocity. The article presents data from computational experiments showing that the integration error when calculating the average flow velocity by a flow meter tends to zero for a laminar flow regime. It has been shown that at low speeds the influence of the flow profile on the accuracy of flow meter readings can be neglected.