TWO-PHASE FLOW MEASUREMENT BASED ON THE ANALYSIS OF THE SENSOR SIGNAL FROM A CONVENTIONAL VORTEX FLOWMETER |
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| M. Pusayatanont, P. J. Unsworth, E. H. Higham |
- Abstract:
- This paper presents a new technique for measuring the volumetric flow rates of each phase in a two- phase gas-in-liquid flow regime, by analysis of the sensor signal from a conventional vortex flowmeter. The vortex flowmeter has become established throughout the process industry for the measurement of both liquid and gas flows, principally because of its wide rangeability, coupled with a nearly linear relationship between the vortex shedding frequency and volumetric flow rate, plus the fact that it has no moving parts which are liable to deteriorate in service.
In recent years, the measurement of multiphase flow has become increasingly important in the management of oil wells, and there are also many instances in the process industries where it would be helpful to have on-line measurements of this type. It has therefore been the subject of extensive research because virtually all available flowmeters are suitable for measuring only single phase flows, and when a second phase is introduced their performance is seriously impaired and in some instances they may cease to function.
It has been known for some time that the presence of a second phase increases the ‘noise’ embedded in the sensor signal from the primary transducer of a conventional flowmeters. Hitherto, this has attracted little attention, but recent studies have shown that the introduction of a second phase into the flow increases the range and amplitude of the high frequency components that are embedded in the sensor signal. These high frequency signals carry useful information not only regarding the flow regime in which the flowmeter is operating but also regarding the status of the flowmeter itself, both of which can be recovered by applying well-established analysis techniques to the sensor signal. To be really effective, it is essential to ensure that all the information that is available at the interface between the flowing fluid and the primary sensor is gathered, and that the primary sensor has the widest possible frequency response.
The object of the study is to provide a method of metering two-phase fluid flow using a vortex flowmeter to yield the volumetric (or mass) flow rates of each component. The presence of a secondary phase within a primary phase changes the features of the flow sensor signal. In the case of air being introduced into water flowing at a constant rate, this produces changes in the features of the sensor signal from which the relative magnitude of the two phases in the gas-in-liquid flow regime can be determined. - Download:
- IMEKO-TC9-2003-064.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