Optimization Design Of Turbine Flowmeter Based On Velocity Distribution Control

Gas turbine flowmeter is one of the three flowmeters used in the gas trade measurement of legally recognized. Because of its high accuracy, high reliability, wide measurement range, repeatability, low pressure loss, etc. It is widely applied in natural gas flow measurement industry. The turbine flowmeter is an important measuring instrument in modern production, people’s livelihood and national development. With the development of large number of gas turbine flowmeters for trade measurement, higher performance requirements have been put forward.In this paper, a gas turbine flowmeter with the diameter of 80 mm has been investigated. It was studied with computational simulation method combined with theory and experiment to focus on the investigation on the pressure loss with the velocity distribution of flow channel in turbine flowmeter. The main research works and results are as follows:Numerical simulation of the turbine flowmeters was researched with different flow values in working conditions. Flow velocity distribution, pressure distribution and the other date of flow channel were obtained. The sonic nozzle gas flow standard device was applied to carry the experiment and the differences between experimental and numerical results are very small. The relationship between flow rate and pressure loss that was induced by each component of turbine flowmeter under different flow rate was analyzed. Get the relationship between velocity and pressure loss of quadratic functions.Calculated the data, the pressure loss coefficient of the components of turbine flowmeter were obtained. The impact of each component on the pressure loss was analyzed. Results showed that, relative to other parts, the rear deflector is the main factors for pressure loss, made about half of total pressure loss. As the flow rate increases, the proportion of the pressure loss increased 12.06%. This provided the evidence for the flowmeter optimization to reduce the pressure loss of the gas turbine flowmeter.According to the above conclusions, an improved idea that combines reducing the pressure loss and optimizing velocity distribution of turbine flowmeter has been proposed. When geometrical structure of the rear deflector has been improved, the numerical simulation results of the new turbine flowmeter showed that, the pressure loss of new rear deflector reduces 121 Pa than the original one. The pressure loss of the new turbine flowmeter decreased 6.02%.