Simultaneous determination of multiphase flowrates and concentrations

Device for determining flow rates of gas and liquid phases of a flow of a multiphase mixture along a pipeline, comprising:

• a. a velocity sensor which is arranged in a section of the pipeline and which is connected to circuitry for measuring a real velocity w of at least one phase of the mixture in the pipeline section;
• b. an acoustic conductivity sensor which is arranged in the pipeline section and which is connected to circuitry for measuring an acoustic conductivity of the mixture in the pipeline section and for determining a volume concentration φ of the gas phase of the mixture in the pipeline section on the basis of the measured acoustic conductivity of the mixture in the pipeline section;
• c. a processor (p. 24 1. 34) which is connected to said circuitry for determining volume flow rates of the gas phase Qg, and of first and second components Q1, Q2 of the liquid phase Ql of the mixture by using values of said real velocity w and said volume concentration;
• further comprising with said pipeline section being a first pipeline section:
• d. a second pipeline section which is arranged in series with the first pipeline section, the first and second pipeline sections having different cross sections, such that a change in flow velocity of the mixture occurs at the junction of the two sections;
• e. a further velocity sensor which is arranged in the second pipeline section and which is connected to circuitry for measuring a real velocity w of at least one phase of the mixture in the second pipeline section;
• f. a further acoustic conductivity sensor which is arranged in the second pipeline section and which is connected to circuitry for measuring an acoustic conductivity of the mixture in the second pipeline section and for determining a volume concentration (p of the gas phase of the mixture in the second pipeline section on the basis of the measured acoustic conductivity of the mixture in the second pipeline section;
• g. a liquid concentration sensor which is arranged in one of said pipeline sections and which is connected to further circuitry for determining a volume concentration W of different liquid phase components of the mixture on the basis of the measured acoustic conductivity of the mixture in said one pipeline section;
• and
• in which the processor is connected to the further circuitry and the processor uses values of the real velocity w and the volume concentrations obtained for the first and second pipeline sections in combination for determining the volume flow rates Qg, Ql, Q1, Q2.