INFLUENCE OF FLOW CONDITIONS ON AN ULTRASONIC FLOW METER |
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| Olivier Broca, Joël Escande, Bruno Delenne, Gérard Mouton, Pierre Gajan, Alain Strzelecki |
- Abstract:
- Multipath ultrasonic flow meters have been more and more used in gas industry for the last ten years, this technology represents an interesting alternative to orifice and turbine meters. In fact, ultrasonic meters offer significant advantages such as bi-directionality, low pressure loss, large range and self-checking capabilities. Nevertheless, in some specific configurations, ultrasonic meters are still sensitive to the installation conditions. During the last decade, this topic has been widely investigated on several aspects, however many questions still remain.
In Ultraflow project, Van Bloemendal et al. and Vulovic et al. examined the behaviour of multipath flow meters located downstream of different pipe fittings, single bend, in or out of plan bends. Their study also focused on the influence of steps in the pipe diameter, the influence of the pressure and the flow meter orientation with respect to the upstream pipe configuration. Lunde et al. performed similar measurements and completed their study with numerical simulations. The work performed at the Gas Research Institute by Grimley combined flow metering error observations with velocity distribution measurements in the pipe. Hilgenstock et al. applied CFD techniques in order to simulate installation effects on ultrasonic flow meters.
A detailed analysis of these works has been carried out, and the metering discrepancies obtained for a same pipe fittings have compared. We tried to determine the influence of different parameters such as the distance between the upstream fittings and the flow meter, the orientation of the flow meter or the pressure level. In most cases, the error decreases with the distance. The influence of the orientation is not obvious and depends on the flow characteristics at the flow meter location. Finally, this analysis indicates that the metering error is quasi-independent of the pressure line. Nevertheless, pressure drop had an influence on the signal to noise ratio and thus on metering error. The CFD techniques has given satisfactory results when applied to relative simple geometries like diffusers or contractions. For more complex geometries, the predictions becomes more hazardous.
Recently, ONERA has developed the ultrasonic tomography to correct the installation conditions influence on different kind of flow meters (Escande et al. and Demolis et al.). The new research program presented in this paper is financially supported by Gaz de France and Gaz du Sud Ouest. - Download:
- IMEKO-TC9-2003-020.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC9
- Event name:
- FLOMEKO 2003
- Title:
- 11th Conference on Flow Measurement
- Place:
- Groningen, NETHERLANDS
- Time:
- 12 May 2003 - 14 May 2003