Focusing on a 36 m³ horizontal pVTt standard container, the intake process and homogeneous process of the gas in the container were numerically simulated in constant wall temperature and constant velocity as the inlet boundary condition. A new algorithm for calculating the average temperature in the standard pVTt container was proposed, whose name was mass temperature average. The simulation results showed that in the natural convection process after gas intake, the average mass temperature T of the gas in the container slowly decreased with time in parabolic shape and tended to wall temperature, while the average pressure drops sharply and quickly reached uniformity. Through numerical simulation and experimental verification, it was found that the gas mass in the container was linear with ln T.

Since 1997, EDF Research and Development Division has been carrying out liquid flow metering studies on the EVEREST experimental loop at EDF Lab Chatou (France). In the last twenty years, industrial flow meters designs have been continuously improved by manufacturers. In the same time, the need for industrial flow measuring instruments with a high accuracy has tremendously increased due to the required economic costeffectiveness in the energy sector. Flow meters metrological assessment tests consequently need to be upgraded in order to remain relevant. In 2016, EDF R&D has then initiated a complete revamping of the EVEREST test bench which was achieved at the beginning of 2019. This comprehensive retrofit leads to a significant calibration accuracy improvement. The EVEREST reference volume flow uncertainty is now better than 0.1% from 50 m³.h-1 up to 1200 m³.h-1. Moreover, in order to characterize the velocity profile impact on industrial meter metrological performance, two laser velocimetry measurement systems have been purchased. This effort leads also to the design of a mini-loop, called MONT-BLANC, whose purpose is to mimic EVEREST calibration features under a smaller size and a lower flow rate rangeability (from 13 m³.h-1 up to 150 m³.h-1). This test bench will allow not only to ease optical adjustments of laser-based velocity measurement techniques and their future implementations on EVEREST but also to provide an effective tool to investigate the influence of scale effect on flow meters and pipes flow physics.

The high pressure sonic nozzle gas flow facility in China was built in NIM at the end of 2014. There were 16 sonic nozzles used as the reference meters in the facility. The flow range is within (2~400) m³/h, while the pressure range is within the (190~2500) kPa. The sonic nozzles were traceable to the pVTt primary standard facility in NIM. To cover the pressure range, the curve fitting between discharge coefficient and Reynolds number was made for each sonic nozzle. To decrease pressure measurement uncertainty, there is an absolute pressure instrument in the manifold in the upstream of the MUT. The expanded uncertainty of meter factor for meter under test (MUT) is 0.15% (k = 2). To verify the uncertainty of the sonic nozzle facility, a comparison between NIM and PTB was made with three Dn 100 turbine meters as transfer meters. The three turbine meters were calibrated by PTB in 2013 with natural gas, which were calibrated in NIM in 2016 and recalibrated in 2017~2018 with dry air. On the base of the good consistency of the comparison results, the uncertainty and the measurement capability of the sonic nozzle facility were verified.

The rapid growth in unconventional gas production has brought with it increased demand for a method of measuring flow rates of both gas and liquid at the wellhead that is more cost effective and reliable than traditional methods (i.e. separator or compensated differential pressure), while remaining reasonably accurate. This paper describes research efforts to determine to what degree a single Coriolis meter is capable of measuring gas and liquid flow rates in wet gas processes, without compositional fluid analysis or other inputs beyond readily available process measurements. This research builds on more than 10 years of development in Coriolis multiphase performance, although previous work has largely focused on small amounts of gas in a liquid process. Coriolis meters have the ability to measure multiple relevant variables: mass flow, density, temperature, tube damping (an indicator of phase fraction conditions), and time. By combining these variables with readily available process variables, such as density of liquid and gas, it is possible to make corrections to errors in Coriolis measurements due to multiphase process conditions and calculate the phase fraction, to apportion the overall mass flow to gas and liquid components.

Due to the predicted exhaustion of oil and natural gas resources by the end of this century, all industrialized countries are taking steps to find alternatives for hydrocarbon fuels. Nuclear energy is expected to be the main source of electricity production by the end of the XXI century. Electricity, however, has some disadvantages related to storage and losses in case of long-distance transmission. Among other sources of energy, the use of which can be possible in the nearest future, hydrogen is the most promising one. The advantages of using hydrogen as a fuel can be summarized as follows: using hydrogen as fuel can be one of the comprehensive solutions to the problem of environmental protection; hydrogen is an excellent energy carrier; as of today, society is largely dependent on fossil energy, while the contribution of sustainable fuel to global energy demand is limited.
Taking into consideration the above, and the possibility of using a mixture of hydrogen and natural gas as a source of energy, the research has been aimed in the following directions:
- Influence of hydrogen impurities on the physical properties of natural gas;
- the effect of adding hydrogen into natural gas on the metrological characteristics of metering systems.