Calibration of an Averaging Pitot Tube for Gaseous CO2 Flowmetering

In this paper, an averaging pitot tube (APT) with flow conditioning wing (FCW) geometry is used as a practical sensing device to measure and characterize the flow of single-phase gaseous carbon dioxide (CO2). This technique demonstrates a simple, cost-effective, and potentially accurate option toward the measurement, accurate accounting, and characterization of CO2 in carbon capture and storage pipelines. The metrological performance of the flow sensor is verified using air medium before being applied for gaseous CO2. With a Coriolis mass flowmeter acting as a secondary calibration reference to further validate the performance of the APT-FCW flow sensor, both metering instruments were evaluated against a weighing scale apparatus. From the experimental and calibration data with air, the APT-FCWs average K-factor and linearity error are found to be 0.5091 and 0.725%, respectively. With operating conditions remaining unaltered in this particular flow measurement application and a target metering error within ±1%, the errors achieved for the Coriolis meter and the APT-FCW are better than ±0.6% and ±1.2%, respectively. Total uncertainty estimations under the stipulated environmental and working conditions are within ±1% and ±1.5% for the Coriolis meter and APT-FCW, respectively. The test results and other performance evaluation of the instruments are also discussed.