The Investigation on the Flow Distortion Effect of Header to Guarantee the Measurement Accuracy of the Ultrasonic Gas Flowmeter

Wenlin Chen,Jianjun Wu,Chunhui Li

doi:10.3390/app11083656

Abstract

The quantification of the flow distortion effect on the measurement accuracy of the ultrasonic gas flowmeter downstream of the header is important but an area that has been of less concern in the research. By experiments and computational fluid dynamics (CFD), the influence of flow field distortion was studied. Experimental results under three different installation conditions showed that when there was flow field distortion downstream of the header, the measurement results of the gas ultrasonic flowmeter were 1% higher than those when there was no distortion, while a flow conditioner could effectively eliminate flow field distortion. Based on the experimental tests, the flow field distribution was analyzed with CFD, which showed that the flow field distortion effect generated by the header had a significant influence on the parameter of nonconforming Profile factor, while the parameters of Symmetry and Cross-flow could be obviously eliminated by the double-cross-section designing.

Highlights

Accurate measurement of the volume of fluid passed is a critical requirement for custody transfer
7the that the differences differences between twounder devices under differ differ ent installation conditions were decreased with the increasing of Reynolds number, installation conditions were decreased with the increasing of Reynolds number, but they ent installation conditions were decreased with the increasing of Reynolds number, bu bu were still much higher than the uncertainty of the best measurement capabilities 0.15%
Based thefield experimental der different installation conditions, of theon flow distortion gene results, the flow field distribution was further investigated by computational fluid dynamics (CFD) simulation

Summary

Introduction

Accurate measurement of the volume of fluid passed is a critical requirement for custody transfer. Due to the unique advantages over other measuring instruments in measurement accuracy, reliability, pressure loss, maintenance cost, and manufacturing cost [3,4], the transit-time multipath ultrasonic flowmeter (TMUSM), taking the places of the traditional mechanical flow meters, has become the best choice [5,6], especially in the field of custody-transfer applications of natural gas. The working principle of TM-USM is shown in Equations (1)–(3) and Figure 1 [7,8], where v is the inlet flow velocity, L is the propagation path length, D is the pipe diameter, φ is the path angle, c is the sound velocity, and i represents a different path. The flow velocity of each path can be calculated by the difference between the downstream propagation time td and upstream propagation time tu : conditions of the Creative Commons

Methods

Results

Conclusion