Experimental investigation of the installation effects on the Venturi flow meter performance (original) (raw)

Experimental Investigation of the Installation Effects on Venturi and Orifice Flow Meters

Résumé L'exactitude et la précision de mesure des débitmètres sont des paramètres métrologiques très importants pour la majorité des industries. La précision des débitmètres dépend principalement de leur position dans le pipeline. Les éléments de conduites tels que les vannes, les coudes et les élargissements brusques sont des sources de distortions et de perturbations pour l'écoulement. Dans le présent travail on présente les résultats d'une étude expérimentale portant sur l'effet des conditions non standards crées par des éléments de conduites sur la précision de mesure des débitmètres à pression différentielle type Venturi et plaque à orifice. Les résultats montrent que les conditions perturbées de l'écoulement peuvent être la cause d'erreur de mesure qui dépassent largement les erreurs limites tolérées par les normes internationales. Abstract Accuracy and precision of flow meters are the most important metrological parameters in most industries dealing wi...

On the Metrological Performances of Differential Flow Meters

Accuracy and precision of flow meters are the most important metrological parameters in most industries dealing with increasingly expensive fluids (water, natural gas and petroleum). The accuracy of these devices depends mainly on their position in a pipe network. Pipe fittings such as valves, bends and other fixtures generate turbulence and swirl and distort the flow distribution in the pipe. The paper presents results of an experimental investigation on the effects of non-standards operating conditions (swirling flows generated by a double bend out of plane) on the accuracy of the orifice flow meter. The results showed that the error caused by such non-standards operating conditions can be very important and is well beyond the error limit tolerated by international standards.

Numerical simulation of multiphase flow in a vertically mounted Venturi flow meter

The objective of the European research project "Multiphase flow metrology in Oil and Gas production" (MultiFlowMet) is to explain and reduce the uncertainty in multiphase flow metering. A comparison of measurements using multiphase metering systems with corresponding results from computational fluid dynamics is used to achieve this goal. In this contribution, a two-phase flow through a vertically mounted Venturi flow meter is presented. According to the experimental set-up within the project, the simulations focus on the flow of oil and gas in large pipes of diameter D = 0.104 m. The simulations represent the whole configuration including a 154D long inflow section, where the flow pattern is formed. After a horizontal bend the flow is turned upwards through a blind-T in the vertically mounted measurement unit. This leads to swirl and turbulence and thus another pattern is observed in the Venturi flow meter. The simulation results are compared with experimental data obtained in the project. Furthermore, the main features of the flow have been extracted by means of data analysis. This allows an easier recognition of the flow pattern and is the basis for a quantitative comparison between experimental and numerical results.

Flow measurement of commercially important fluids

Flow Measurement and Instrumentation, 1990

This well attended conference (200+) was opened by the Chairman, Dr Tony Spencer, indicating how the emphasis on flow measurement has changed over the years while he has been working at NEL and now for the EEC. The increasing demands by more areas of industry for increased accuracy, flexibility and flowrates was outlined. Indeed, every industry has a need to monitor a flow somewhere in its processes. Calibration techniques The first day began with a paper on calibration techniques. Young outlined the general principles of absolute calibration and how they have been implemented at a new Danfoss site, with an emphasis on repeatability, traceability and an accuracy of 0.1%. Professor Heitor from IST, Portugal, described a multinational project to compare flow measurements from different sites, given a standard pipe configuration and flow conditions. LDA and hot-wire methods are used to study the flow of air and water through diffusors and contractors at various Reynolds numbers (10 s-2 x lOS). Intercomparisons of the experimental results are being made, and also comparisons with various computational models. The results gathered so far agree well with each other, though there are some discrepancies downstream of the diffusor that have yet to be accounted for.

Installation effects upon orifice flowmeters

Flow Measurement and Instrumentation, 1992

An experimental study has been undertaken to quantify the effect of the inlet velocity distribution upon the coefficient of discharge, Cd. A two inch (50.8 mm) diameter orifice run was operated at a Reynolds number of 91 000 with a beta ratio, ~, of 0.75. The upstream pipe section was replaced with a one inch pipe mounted concentrically inside the two inch pipe. The mass flowrate was held constant by an array of sonic nozzles upstream of the concentric pipes and was split between the two. By varying the ratio of the flow split, various inlet velocity profiles were generated. The results show that the change in coefficient of discharge is related to first-, second-and third-order moments of momentum: shows the same relationship. This paper proposes the use of this correlation to develop criteria for correcting the discharge coefficient given the variation of the inlet velocity profile from "fully developed' fow. The velocity profile can be measured at the upstream flange tap location with the orifice plate removed, and that profile can be used to generate the moment of momentum to be used to correct the coefficient of discharge.

Behaviour of Venturi meters in two-phase flows

2018

Needs for accurate and reliable on line metering of two-phase flows (gas and/or liquids) are arising for fiscal and allocation reasons when subsea or topside installations are shared by several partners. This paper describes the work carried out by ELF EXPLORATION PRODUCTION and GAZ DE FRANCE in collaboration with the ONERA research centre to assess and develop accurate methods applicable for gas metering with condensate ("wet gas"). After a review of allocation metering requirements and available techniques for flow rate measurements in high gas fraction conditions (GVF>95%), this paper deals with the behaviour of Venturi flow meters in similar two-phase flows. The applied methodology, which combines experimental laboratory testing in ONERA, numerical simulation and field evaluation is described. The preliminary results obtained on the Venturi meter in different two-phase flow configurations (annular, mist) are presented. The influence of some flow parameters (liquid c...

Upstream velocity profile effects on orifice flowmeters

Flow Measurement and Instrumentation, 1994

The effects of upstream velocity profile on the performance of orifice flowmeters were studied. Non-swirling maldistributed axial velocity profiles were obtained using a concentric pipe flow conditioner. Orifice flowmeters with/3 ratios of 0.43, 0.50, 0.60, 0.70 and 0.75 were installed downstream of the flow conditioner and operated at a Reynolds number of 54 700 in a 50.4 cm pipe. Increasing the flow along the centreline of the pipe decreased the pressure drop across the orifice plate, resulting in increased discharge coefficients. The opposite was observed as the flow along the pipe centreline was decreased. The errors increased with increasing/3 ratio. A swirl generator was installed upstream of the/3 = 0.43 and 0.50 orifice plates. The swirl produced effects opposite to the axial velocity. The change in discharge coefficient increased with decreasing /3 ratio.

Evaluation of Orifice Flow Meter Accuracy under Pulsation Conditions

Advanced Materials Research, 2015

Orifice meter is a flow measuring device which is widely used in various industrial applications. Although the device gives accurate measurement during steady flow, measurement errors related to square root and sampling errors are unavoidable if pulsations exist. This research investigatesand improves the performance of an orifice plate flow meter under pulsation effects. A simple model for the pulsating flow through an orifice meter is presented. Square root error (SRE) is estimated. Sampling errors (SE) are reduced by proper selection of the averaging time.

Flow Velocity Distribution Towards Flowmeter Accuracy: CFD, UDV, and Field Tests

Water, 2018

Inconsistences regarding flow measurements in real hydraulic circuits have been detected. Intensive studies stated that these errors are mostly associated to flowmeters, and the low accuracy is connected to the perturbations induced by the system layout. In order to verify the source of this problem, and assess the hypotheses drawn by operator experts, a computational fluid dynamics (CFD) model, COMSOL Multiphysics 4.3.b, was used. To validate the results provided by the numerical model, intensive experimental campaigns were developed using ultrasonic Doppler velocimetry (UDV) as calibration, and a pumping station was simulated using as boundary conditions the values measured in situ. After calibrated and validated, a new layout/geometry was proposed in order to mitigate the observed perturbations.