The New Semi-Experimental Method for Simulation of Turbine Flow Meters Rotation in the Transitional Flow
The new semi-experimental method for simulation of the turbine flow meters rotation in the transitional flow has been developed. The method is based on the experimentally established exponential low of changing of dimensionless relative turbine gas meter rotation frequency and meter inertia time constant. For experimental evaluation of the meter time constant special facility has been developed. The facility ensures instant switching of turbine meter under test from one channel to the other channel with different flow rate and measuring the meter response. The developed method can be used for evaluation and predication of the turbine meters response and dynamic error in the transitional flow with any arbitrary law of flow rate changing. The examples of the method application are presented. Keywords—Dynamic error, pulsing flow, numerical simulation, response, turbine gas meters.
ANALYSIS OF NONLINEARITY OF THE TURBINE GAS METERS TIME CONSTANT DURING STEP RESPONSE
The step response of the turbine gas meter has been studied experimentally. Using the specially developed method the turbine gas meter rotation inertia time constant during step response has been evaluated. It has been found that the time constant depends not only on the final value of flow rate, but also on the current rotation frequency of the meter rotors. The results can be used for calculating the dynamic error of different types of tachometric meters with pulsing flow rate. DOI: http://dx.doi.org/10.5755/j01.mech.19.5.5544
Field tests of correction procedures for turbine flowmeters in pu satile flows
Abstract Turbine flowmeters are known to be susceptible to over-registration errors in pulsatile gas flows. The results of applying three possible correction procedures to the outputs from meters installed in Dutch natural gas supply lines are compared. Large amplitude, periodic flow variations were observed both due to pressure regulator oscillations and to irregular gas usage. Errors as high as 60% were observed. Correction procedures assuming sinusoidal pulsation profiles were found to be inappropriate in these flows. Except for intermittent flows, correction to an accuracy of better than ±2% was found to be possible.