| 摘要 |
A multi-phase flow meter includes a flow conduit leading from an inlet to an outlet and comprising a variable inlet restriction, a variable outlet restriction, a pressure sensor and a volumetric flow meter, located between the variable inlet restriction and the variable outlet restriction, the flow meter further comprising a controller adapted to receive data from the pressure sensor and the volumetric flow meter, and to adjust the variable inlet restriction and the variable outlet restriction in accordance with at least one program, wherein the at least one program causes the controller to adjust one of the variable inlet restriction and the variable outlet restriction such that the fluid pressure between them adopts a first pressure, then further adjust the restriction such that the fluid pressure between the restrictions adopts a second and different pressure, and to record the first pressure, the second pressure, and the volumetric fluid flow rates at the first pressure and at the second pressure, whilst adjusting the other of the variable inlet restriction and the variable outlet restriction so that the total flow restriction imposed by the two restrictions is maintained at a substantially constant level. Thus, the control arrangement can vary the flow restrictions in concert so as to control or maintain the pressures in surrounding flowlines while varying the pressure in the flow conduit between the restrictions. This allows the calculation of the relative proportions of gas and liquid phases in the fluid that is flowing through the device. The device can also comprise a mass flow meter located between the inlet and the outlet flow restrictions; with knowledge of the proportion of liquid in the fluid flow, and of the relative densities of the liquids that are flowing, this then allows calculation of the relative fractions of different liquids, based on the measured volumetric and mass flow rates. |
