What type of flow meter is suitable for high-temperature and high-pressure hydrogen?
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As title； Originally, an Anubaa flow meter was used, but its measurements were inaccurate. The process parameters are: pressure of 4 MPa, temperature of 290 °C, and pipe diameter of DN400. Is it possible to use an external ultrasonic flow meter? Or do any of you have any good recommendations?
I don’t know your flow rate, but mass flow meters are also a good option.
For mass flow meters used in conditions involving hydrogen measurement, they will also be inaccurate and exhibit measurement errors; however, compared to other types of meters, they offer better stability and consistency. Ultrasound is indeed an option, but it’s not clear what the actual performance will be like. I have encountered similar situations before, but not for hydrogen measurement.
External ultrasonic clamping can be used for measurement, but it is relatively expensive. If other types of flow meters are used, special requirements may arise regarding the material used. However, it is best to avoid using differential pressure flow meters, as high-pressure hydrogen causes severe hydrogen erosion of the diaphragm; even diaphragms with an inner or outer gold coating may not remain stable.
If the flow range is appropriate, vortex flow meters will work, of course those that are of reliable quality.
It’s best to find out the reason for the inaccurate initial measurement before considering the next steps. Firstly, the measurement accuracy of ordinary external clamp-type ultrasonic flowmeters is inferior to that of Anubaa. The reasons for the inaccurate measurements with Anubaa may be as follows: 1. A longer straight pipe section is required, which cannot be achieved in actual installation conditions ； 2. The differential pressure of orifice-type throttling elements is low; therefore, a high-quality differential pressure transmitter is required to achieve accurate measurements ； If it’s possible to improve Ainiuba’s measurement system, it’s definitely the best option not to replace the flow meter. Secondly, vortex flow meters are indeed a good choice. However, the DN400 diameter is quite large, and for high-pressure hydrogen pipelines (>3.0 MPa), the standards specify that the maximum flow velocity should not exceed 10 m/s (for carbon pipes). When using vortex flow meters, it is necessary to take into account the flow velocity of the hydrogen gas after the diameter is reduced.