Study On The Optimal Design Of CNiM-TM Series Gas Turbine Flowmeter

As an traditional flow measurement instruments, because of its highprecision、wide flow range and low pressure loss. So it is widely applied in naturalgas、petroleum、chemical industry and other flow industry. The turbine flowmeter iswidely used in modern production and livelihood. Under the present increasinglyserious resource situation, to test instruments for the measurement of natural gas putforward higher requirements, highlighted the importance of improving theperformance of turbine flowmeter. This paper applied three kinds ofresearch methods, the theory, the numerical simulation and the experiment to focuson the investigation on how to reduce turbine flow meters’ linear error. In this paper,CNiM-TM-DN80gas turbine flowmeter have been investigated. The main researchwork is as follows:On the theory, to quantify various parameters of the impeller firstly, and then bypotential flow theory、theorem of momentum and continuity equation for theimpeller rotation process, to established of a complete turbine flow-viscositymathematical model. Based on this model, using nonlinear MultivariableOptimization methods for reducing the research of turbine flow meters linear error,and arrive at optimized impeller parameter.On the numerical simulation, in strict accordance with the practical，Thethree-dimensional80gas turbine flowmeter models were established. The FLUENTwas used to get the meter factor and the internal flow of turbine flowmeter. Theimpeller’s rotational speed is a problem in Numerical calculation, The user-definedfunction（UDF）and the dynamic mesh of FLUENT were introduced, writing the Cprogram to calculate the impeller’s rotational speed under the given flow rate, andthen output the calculation speed of impeller of the results and comparison withexperimental results verify reasonably, given its internal flow’s velocity and pressuredistribution. Finally, theoretical study concluded that data back into thethree-dimensional modeling of the impeller, then study on the new impeller’srotational speed, get the structural parameters which can be able to reduce for linearity errors of turbine flowmeter.On the Experimental，the pressure loss and instrument coefficient of the turbineflowmeter was calibrated by the sonic nozzle gas flow standard device，which wasused to verify the results of numerical simulations and theoretical research.