FLOWMETER FOR TWO-PHASE FLUID

A flowmeter (1) for liquid/gas cryogenic two-phase fluids, comprising: - an inlet duct for the fluid of which the flow rate is to be measured, in the flowmeter, which duct is provided with a calibrated orifice (8); - a system provided with a vertical reservoir (5), into which reservoir the duct opens, the wall of the reservoir being provided with a plurality of slots (6) for discharging the fluid (7) from the reservoir (5) towards the interior space (9) surrounding the reservoir (5); - pressure sensors for measuring the following pressure differences: * a pressure difference (ΔP3) between the upstream and downstream sides of the calibrated orifice * a pressure difference (ΔP1) between the bottom of the reservoir (5) and the atmosphere surrounding the reservoir within the interior space (9) * a pressure difference (ΔP2) existing between two points located in the space surrounding the reservoir (5) within the interior space (9); - a data acquisition and processing system capable of determining information on the state of the entering fluid and of determining the flow rate by using either the pressure differential ΔP3 when the fluid is 100% gaseous or 100% liquid (subcooled) or the pressure differential ΔP1 which makes it possible to deduce the height of liquid in the reservoir and consequently the flow rate of fluid (7) passing through the slots.