Measurement of hydrocarbon liquid flow rate using volumetric and gravimetric methods: comparison between KRISS and PTB hydrocarbon standard systems |
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| S. H. Lee, M. Link, B.-R. Yoon, E. Frahm |
- Abstract:
- In this study, the hydrocarbon liquid flow rate was measured using both volumetric and gravimetric methods. Both methods are representative reference techniques for measuring the hydrocarbon flow rate. The volumetric method uses a calibrated volume tank, while the gravimetric method is based on a calibrated balance. Using these two methods, which have different traceability systems, a Coriolis flowmeter was calibrated under comparable flow conditions. The deviation and uncertainty of the flow measurement results obtained from the volumetric and gravimetric methods were analyzed.
The study included the calibration of a 1000 L reference volumetric tank at the PTB hydrocarbon facility by using two different approaches: a filling method and a gravimetric method. For the filling method, a 100 L reference volume pipette was installed above the volume tank. A balance system under the 1000 L tank was used to calibrate the tank based on the gravimetric method. The uncertainties of the filling and gravimetric methods were 325.18 ml and 171.39 ml (k = 2), respectively, and the maximum difference between these methods was 78.06 ml. Thus, the calibration values of both methods were found to agree with each other within the estimated uncertainties.
For the final comparison, a Coriolis flowmeter was calibrated using the 1000 L volume tank at the PTB flow facility. The diameter of the pipeline was 80 mm and the flow rate ranged from 13.68 t/h to 54.81 t/h. A balance reference was used at the hydrocarbon flow systems of KRISS. Since the fluid properties (density and viscosity) used at the two institutes are different, the flow measurements were compared based on the Reynolds number to compensate for these fluid properties. The calibration values of the Coriolis flowmeter at KRISS and PTB were 0.21–0.23% (U=0.08%, k = 2) and 0.18–0.24% (U=0.05%, k = 2), respectively, for an Re number range between 35,000 and 145,000. The results from the gravimetric method in KRISS matched very well with the results from the volumetric at PTB, within the estimated uncertainties. Thus, we confirmed that the hydrocarbon flow standard systems of KRISS and PTB have traceability when using the volumetric and gravimetric methods in the given range of Re number. The procedure and results of the volume tank calibration at the PTB hydrocarbon facility will be given during the presentation. In addition, the results of the flow comparison between PTB and KRISS will be presented to demonstrate the traceability of both hydrocarbon laboratories. - Download:
- IMEKO-TC9-2019-045.pdf
- DOI:
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- Event details
- IMEKO TC:
- TC9
- Event name:
- FLOMEKO 2019
- Title:
18th International Flow Measurement Conference 2019
- Place:
- Lisbon, PORTUGAL
- Time:
- 26 June 2019 - 28 June 2019