Experimental verification of the temperature effect on ultrasonic volume and flow meters processing air, methane, and hydrogen

The energy transition includes the decarbonization, among others, of the residential sector, a goal that could be enabled by hydrogen technologies. In this context, volume and flow meters are needed for the evaluation of the hydrogen consumptions by end users. This work exploits an experimental apparatus for testing flow meters inside a climatic chamber at diverse ambient temperatures with hydrogen, as well as with air and methane for sake of comparison. Here two novel ultrasonic meters for domestic application are tested. They have been developed by Pietro Fiorentini S.p.A. in the framework of the Hy4Heat project. Tests with hydrogen are carried out at flow rates up to 20 m3/h, while those with methane and air are performed at flow rates up to 6 m3/h (where volumes are referred to standard conditions of 15 °C and 101.325 kPa). All the tests are performed in controlled conditions, at ambient temperature equal to +15 °C, and extreme temperatures equal to +55 °C and -25 °C. All the recorded measurements are processed with a dedicated data analysis protocol for the verification of the testing conditions. The deviations of the volume and flow meters are calculated with respect to reference thermal mass flow meters; then, the deviations at extreme temperatures, +55 °C and -25 °C, are normalized against the ones obtained at ambient temperature, +15 °C. Such comparison shows a normalized deviation falling inside the 2/3 of the limit imposed by the legislation, with all the fluids .