Mobile H2 measuring for METAS
HFTS2: A new mobile measuring system for gravimetric H2 measurements
To ensure that the H2 filling stations meet the metrological requirements and can be calibrated in a traceable manner, the Swiss Federal Institute of Metrology METAS (hereinafter referred to as METAS) has built a mobile measuring system for the gravimetric determination (scales) of the delivery volume of hydrogen filling stations.
In 2017, Swagelok Switzerland was able to supply METAS with pipe fittings, couplings, non-return and control valves, pressure gauges and metal hoses for this H2 measuring system. See post
In 2023, the new H2 measuring system was installed in a mobile trailer. A short video made during the installation gives you an insight into the progress of the project.
In order to give you an overview of the project and the further development of the measuring system, we would like to go into a few important points:
A European project "MetroHyVe2" is currently running, which aims, among other things, at further development (namely a mobile and calibrated master meter connected in series between the fuel pump and the refueling object). The project will run until the end of 2023. METAS is focusing on the new development of a larger, mobile measuring system, which is also based on the gravimetric measuring principle - the HFTS2.
The measuring system HFTS2 (Hydrogen Field Test Standard) is part of the "MetroHyVe2" project. Due to the increased tank volume, this system can also be used in the future to test dispensers that are intended for refueling heavy-duty applications, e.g. B. Trucks and trains. Larger mass flows can be achieved with the HFTS2, which then correspond better to the application in practice (explanation: the SAE protocols limit the gradient of the pressure increase in the vehicle tanks. With large tank volumes, the tolerated mass flows also increase during the refueling process). Comparison: The HFTS2 with a tank volume of 600 liters roughly corresponds to the real tank volume of today's Hyundai trucks. With the mobile HFTS2, METAS can calibrate and test large hydrogen tank volumes flexibly and efficiently on site.
Time savings and flexibility thanks to the mobile trailer
The inside temperature can already be regulated during the outward journey. In this way, the entire mass is already thermally stabilized at the customer's site and the problem of convection currents is reduced. Since all the electronics and data acquisition are also in the trailer in the non-hazardous area, the scales can already be supplied with power on the journey. This reduces the otherwise necessary warm-up time of the scales on site by around 2 hours. In addition, we can now carry out measurements on the trailer even in strong wind and rain due to the extremely stable and play-free hydraulic feet (4 pieces), with which the trailer can be leveled exactly in the horizontal position and the stiff outer shell (glass fiber composite hard shell). The aim of the measuring system is therefore an increase in efficiency due to the mobile application possibilities without warming up the scales.
The sensors (pressure and temperature transmitters) attached to the mass to be weighed (pressure tanks) use Bluetooth technology. This eliminates the need for complex and expensive intrinsically safe circuits (ATEX) and annoying cable connections, which previously had to be decoupled for each weighing and then reconnected afterwards. On the one hand, the measuring system itself (in the hazardous area) is of course installed in the trailer, as are the electronics and data acquisition. Other components are the compressed nitrogen gas N2 for inerting the tanks and fittings of the pipes, accessories and tools, etc. This means that the system is ready for operation quickly and safely. Incidentally, the atmosphere in the Ex zone in the trailer is continuously and redundantly monitored with H2 sensors. When certain concentration values are reached, an audible and/or visual alarm sounds. Like the HFTS1 hydrogen measuring system, the entire system is fully ATEX Zone 2 certified. The definition of the ex-zones as well as the ignition hazard assessment was carried out in cooperation with SUVA. The Swiss Safety Center regularly checks the system with a pressure gas test at 1050 bar.
Why did Metas choose Swagelok as a partner? Quality and service from a single source speak for Swagelok. The experience of Swagelok products with the HFTS1 hydrogen measuring system has been consistently very good. The system was moved about 6000 kilometers in the trailer. There was not a single leak. METAS has never even followed up or replaced a single connection. In addition, we no longer wanted to carry out the engineering of the piping, the dimensioning of some critical functions and the assembly of the HFTS2 measuring system ourselves.
The following products from Swagelok were used: All components that come into contact with H2 and N2, such as pipe fittings, couplings and non-return control valves and stainless steel tubes.
In addition, Swagelok has chosen FK fittings wherever possible for excellent vibration resistance. Find the full range of hydrogen compatible products hier.
We are proud to have supported METAS in this groundbreaking project and look forward to further cooperation in the future. If you have any questions or require further information, we are at your disposal.
Email info@arborag.ch | Tel. +41 56 485 61 61