| Every year mischarges on the order of hundreds of millions of dollars are incurred to the natural gas industry due to the uncertainty in orifice metering accuracy. To this day there are still efforts being undertaken to alleviate the problem by improving measurements with existing orifice meters through metering standards. It stands to reason that if a viable alternative could be developed the economic implications to the industry would be enormous. Consequently, a new flow meter has been developed. It is a plate-type differential pressure meter which can be "drop-in" replacement to the current meter. Key to this device is a circular array of radial slots which allow passage of the fluid. The slotted orifice meter has shown potential in previous studies and is expected to perform well. The objective of this study was to increase the knowledge base of the slotted plate to the point that a marketable design can be developed. This was accomplished by examining the performance of the slotted plate orifice meter for a variety of conditions which may be seen to effect meters "in the field." These conditions include: ill-conditioned velocity profiles, tube bundle location, compressibility, and flowrate. Also studied was the slot inlet contour and the effect of line size which will enable designs to be scaled for larger (or smaller) pipe diameters. In addition, numerical studies using the commercially available FLUENT code from Fluent Inc. were completed to complement experimental findings. |
