摘要 |
A flow rate measuring method for a multiphase fluid mixture FM flowing into a line LN, the fluid mixture FM comprising at least a first and a second phase, the method comprising the steps of: passing the fluid mixture through a Venturi tube in which the fluid mixture is subjected to a pressure drop, continuously measuring by means of said Venturi tube permanently installed on the line a differential pressure across the Venturi tube DeltaPv and a line pressure of the fluid mixture in the line Pi, punctually measuring at a determined instant by means of a second measuring device removably installed on the line at least one measured parameter of the fluid mixture correlated to the first phase quantity relatively to the second phase quantity, continuously determining at least one estimated parameter of the fluid mixture correlated to the first phase quantity relatively to the second phase quantity based on the punctually measured parameter and an extrapolating scheme, and determining at least one phase flow rate based on the differential pressure across the Venturi DeltaPv, the line pressure of the fluid mixture into the line Pi and the at least one measured parameter of the fluid mixture when the second device is installed on the line, and determining at least one phase flow rate based on the differential pressure across the Venturi DeltaPv, the line pressure of the fluid mixture into the line Pi and the at least one estimated parameter of the fluid mixture when the second device is removed from the line.
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