Evaluation of hydrocarbon flow standard facility equipped with double-wing diverter using four types of working liquids

Abstract

A flow calibration facility based on the gravimetric method using a double-wing diverter for hydrocarbon flows from 0.1 m 3 h −1 to 15 m 3 h −1 was constructed as a national measurement standard in Japan. The original working liquids were kerosene and light oil. The calibration facility was modified to calibrate flowmeters with two additional working liquids, industrial gasoline (flash point > 40 °C) and spindle oil, to achieve calibration over a wide viscosity range at the same calibration test rig. The kinematic viscosity range is 1.2 mm 2 s −1 to 24 mm 2 s −1 . The contributions to the measurement uncertainty due to different types of working liquids were evaluated experimentally in this study. The evaporation error was reduced by using a seal system at the weighing tank inlet. The uncertainty due to droplets from the diverter wings was reduced by a modified diverter operation. The diverter timing errors for all types of working liquids were estimated. The expanded uncertainties for the calibration facility were estimated to be 0.020% for mass flow and 0.030% for volumetric flow for all considered types of liquids. Internal comparisons with other calibration facilities were also conducted, and the agreement was confirmed to be within the claimed expanded uncertainties.

Primary standard for traceability in low liquid hydrocarbon fuel flow rates

“…To validate the CMC of the facility discussed in this study, intra-facility comparison between the gravimetric systems within the facility as well as inter-facility comparisons with other calibration facilities in NMIJ (of which 2 primary standards [4,25] are linked to the international key comparisons of CCM.FF.K1 [26,27] and CCM.FF.K2 [21][22][23][24]) were performed. All the comparisons conducted through a total of six different transfer meters show a good agreement between the facilities, hence providing supporting evidence for the CMC claimed by the facility.…”

“…(a) Inter-facility comparison between the small oil flow facility and the medium oil flow facility [4], which is linked to CCM.FF-K2 international key comparisons [21][22][23][24]. (b) Inter-facility comparison between the small oil flow facility and the small water flow facility [25], which is linked to CCM.FF-K1 international key comparisons [26,27].…”

“…1 significantly affected the calibration result near the bottom limit of the measuring range of the Coriolis meter. As shown in figure 9(a), the calibration results Figures 11(a)-(d) show the results of the inter-facility comparisons conducted between the small oil flow facility (2 kg gravimetric system) and the medium oil flow facility [4] over an overlapping flow range, using three transfer meters, namely one Coriolis mass flowmeter (No. 1) and two PD volumetric flowmeters (No.…”

“…This posed a huge challenge for us in developing a calibration facility versatile enough to cater to the wide flow range and safe enough to operate on flammable hydrocarbon fuels with an expanded uncertainty aimed at below 0.1%. Primary standards at NMIJ had been providing calibration coverage from 0.1 m 3 h −1 to 300 m 3 h −1 [3,4]. Hence a new facility was intended to expand the bottom limit (0.1 m 3 h −1 = 100 L h −1 ) of the calibration coverage to the lowest flow rate of 0.02 L h −1 performed at the engine test bench.…”