The need for carbon dioxide reduction and accurate metering of fuel flows have led environmental policies to a new perspective. The application of numerical investigation could be useful to predict the behaviour of meters for using new green fuels, avoiding expensive experimental campaigns. This paper adopts the Eulerian approach to numerically analyse the transient, isothermal, and turbulent flow across an orifice plate flowmeter. Numerical results are validated against an experimental campaign, conducted by the Research Institutes of Sweden (RISE). The validated numerical model is adopted to evaluate the performance of the flowmeter in the case of employing two different innovative fuels (biodiesel). The developed numerical tool has also been applied to the simulation of a dynamic inlet flow rate. The obtained results demonstrate the capability of the numerical model to predict the flow rate for the studied scenarios, as well as the difficulties of the investigated meter in performing under dynamic boundary conditions.

Operating and calibration conditions of flow meters vary considerably and have been the subject of various investigations over the years. Based on the knowledge gained and the development of test capabilities that has taken place in the meantime, the investigation of operational influences on the measurement behaviour of the devices can be further advanced. These efforts are driven by stricter requirements on the part of the users of flow measurements, who use these measurements for process optimisation or to prove compliance with given limit values. In the EMPIR project 20IND13 “Safest” infrastructure has been developed enabling a dynamic characterization of flow meters linked to different kinds of flow meter applications. In addition, eventual effects on flow measurements due to changes in ambient and fluid temperatures or deviations between them were investigated. The results for different types of flow meters such as Coriolis and screw spindle meters are presented and discussed. 

The maritime sector is working hard to reduce greenhouse gas emissions. Overall, the shipping industry is under considerable pressure to identify innovative solutions, including a transition from conventional to cleaner fuels by 2050. The most promising future fuels are ammonia, ethanol and methanol, which have lower viscosities than current fuels. These new generation fuels are sustainable and have the potential to significantly reduce greenhouse gas emissions. Positive displacement meters are one of the most common types of flow meters used to measure fuel in the marine sector. However, they usually require a certain viscosity to perform properly. The aim of this study is to investigate the measurement performance of a prototype positive displacement fuel consumption meter capable of measuring next generation marine fuels and fuel blends with these and established fuels. The paper outlines the development of the prototype and how it was subsequently improved. Measurements were carried out on the prototype with fuels of different viscosities and line pressures relevant to shipping. The results prove that the meter operates almost independently of viscosity and pressure, making it suitable to accurately measure today’s (current fuels), tomorrow’s (blended fuels) and future fuels. Finally, suggestions for further improvements are given. 

This paper gives an overview of investigations with a newly developed pressure-driven flow controller, which has no mechanical components and can therefore provide pulsation-free flows. The performance of the pressure-driven flow controller is compared with high-precision syringe pumps used as reference systems in most laboratories and National Metrology Institutes. The results show an astonishing performance of the pressure-driven flow controller, but also a strong dependence on the associated flow sensor. In contrast to a high-precision syringe pump, the system with a flow sensor is much more dependent on fluid properties, pressure and temperature. However, the strength of the pressure-driven flow controller lies in rapid flow changes and flow stability. Here the system gives excellent results. Another advantage of the system is that direct access to pressure values makes it easy to measure hydrodynamic resistances, which are important for lab-on-a-chip and organ-on-a-chip applications.

To meet the new regulation for the deployment of alternative fuels infrastructure which sets targets for electric recharging and hydrogen refuelling infrastructure by 2025 or 2030, a large infrastructure comprising truck-suitable hydrogen refuelling stations will soon be required. However, further standardisation is required to support the uptake of hydrogen for heavy-duty transport for Europe’s green energy future. Hydrogen-powered vehicles require pure hydrogen as some contaminants can reduce the performance of the fuel cell even at very low levels. Even if previous projects have paved the way for the development of the European quality infrastructure for hydrogen conformity assessment, sampling systems and methods have yet to be developed for heavy-duty hydrogen refuelling stations (HD-HRS). This study reviews different aspects of the sampling of hydrogen at heavy-duty hydrogen refuelling stations for purity assessment, with a focus on the current and future specifications and operations at HD-HRS. This study describes the state-of-the art of sampling systems currently under development for use at HD-HRS and highlights a number of aspects which must be taken into consideration to ensure safe and accurate sampling: risk assessment for the whole sampling exercise, selection of cylinders, methods to prepare cylinders before the sampling, filling pressure, and venting of the sampling systems. 

To link traceable flow calibrations of Coriolis meters at ambient conditions to flow measurements in cryogenic, liquid hydrogen (LH2) applications, physical effects of very low temperatures on the calibration factor must be satisfactorily predicted by temperature correction methods. In this paper, four correction models are investigated, which differ in the sense of which temperature effects they cover and how these effects are determined. These correction models were applied to three Coriolis meter designs – straight, arc and U-tube. As a reference value in the evaluation, we use the simulation results with the finite element model that incorporates temperature effects related to elastic material properties, thermal strains and thermal stresses. The best agreement (within ± 0.2 % for the curved tubes) is achieved by the correction model that considers the known temperature dependence of the tube elastic properties as well as the dimensional changes due to thermal strain. 

Reliable fuel consumption measurements play an essential role in the maritime sector whether for emission determinations or the use of novel fuels. A verification of the performance of flow meters used for fuel consumption determination under realistic conditions is thus of interest. Apart from the influence of the pressure- and temperature-dependent transport properties of the fuels, a characterization of the measurement performance under dynamic fuel consumption is of relevance. Traceable metrological infrastructure and procedures, which will enable an evaluation of the measurement performance of flow meters in this regard, are being developed in the scope of the EMPIR project “Safest” (20IND13). A consumption profile of a ferry navigating in a harbour serves as basis. In addition to the measurement accuracy under dynamic conditions, first investigations of the performance of flow meters are carried out in terms of fluid temperature and fuel transport properties for the example of spindle screw meters.

This paper gives an overview of the ongoing Joint Research Project (JRP) 20IND11 “Metrology infrastructure for high pressure gas and liquefied hydrogen flows” (MetHyInfra), which will ensure traceability in the hydrogen distribution chain. For this purpose, very precise nozzles with well-defined geometries have been produced. In this project, Critical Flow Venturi Nozzles (CFVNs) will be traceably calibrated for the first time with hydrogen and pressures up to 100 MPa using a Coriolis Flow Meter (CFM) as a secondary standard. A CFM has been successfully calibrated with hydrogen against a gravimetric primary standard. Equations of State (EoS) are important for the high-pressure calibration of the nozzles, but also for Computational Fluid Dynamics (CFD) simulations. With regard to CFD, a numerical model has been developed to simulate high pressure hydrogen flow in the CFVN. In a parameter study, non-ideal nozzle shapes are investigated using a shape variation parameter. New Speed of Sound (SoS) measurements were conducted at temperatures from 273 to 323 K and pressures from 1 to 100 MPa. These new data were then used to develop a new EoS for normal hydrogen, optimized for gas phase calculations. In addition to gaseous hydrogen, the project has a strong focus on liquefied hydrogen. Here a three-pronged approach allows traceable measurements. Each of the approaches presented is based on a unique flow calibration principle and relies on independent traceability schemes. The results of the project will ensure traceable measurements and thus a higher level of confidence among end users. © 2024 The Authors

It is foreseen that hydrogen heavy-duty (HD) vehicles will be used to a large extent to support the transition to zero emission transport in Europe by 2050. Ensuring the quality of hydrogen is crucial to guarantee a smooth transition. To demonstrate the quality of hydrogen, sampling systems adapted to HD conditions are being developed and tested as part of the EU-funded project MetHyTrucks (Metrology to support standardisation of hydrogen fuel sampling for heavy duty hydrogen transport). Poor sampling can lead to damage to fleets of HD vehicles, making standardization crucial for the shared HD Hydrogen Refuelling Station (HRS) network. Reliable, specific sampling systems for HD-HRS, designed for both gaseous and particulate phases, are currently being developed in the European Partnership on Metrology project MetHyTrucks. The dynamic nature of a HD-HRS, with changes in pressure, flow and temperature during refuelling, can affect the reliability of sampling. Moreover, the hydrogen fuel sampling at the HD-HRS is an operation performed in a potentially explosive atmosphere area involving safety risks. This paper discusses the parameters that can affect sampling when assessing hydrogen purity at a HD-HRS. 

The European Partnership on Metrology project BiometCAP (Protocol for SI-traceable validation of methods for biomethane conformity assessment) has developed a comprehensive performance assessment protocol tailored to benchmark and characterise analytical systems such as gas analysers. The outcomes, including practical tests, will contribute to the development of standards. This article highlights some of the findings obtained so far in the BiometCAP project, showing the applicability of this protocol to assess the performance of analysis techniques used for quantifying terpenes, siloxanes and halogenated volatile organic compounds in biomethane.