Selection of hydrogen flow meter
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Dear colleagues, operating conditions: 0.5 MPa, DN100, flow rate of 800–3500 Nm3/h. The rotor from Croni was chosen initially; the selected range was a bit too large, and its accuracy was 1.5%, resulting in fairly large errors. The required accuracy is 0.5% FS; it can also be relaxed to 1%. What type of flow meter do you recommend? Vortex street or thermal mass? I haven’t used thermal mass before; what’s its price?
It is best to use a mass flow meter, taking into account factors such as explosion protection, pressure drop, and accuracy. With enough money, I think I don’t need to consider vortex flow meters, turbines, orifice plates, nozzles, velocity tubes, or rotors. . Thermal mass flow meters are a bit more expensive, but they can be used for several years without any problems, and they also offer good stability. . . . We can cooperate if needed
Mass flow meters are too expensive; vortex flow meters, orifice plates, and similar options are available. Feel free to contact us if you need any assistance
The price of mass flow meters isn’t as scary as you say; our products have significant advantages in terms of convenience and cost-effectiveness.
This DN100 mass flow meter of his must be quite expensive, right?
This is in the standard size. Domestic brands currently offer quality that will last 3–5 years without any problems. Our prices are only 1/3 to 1/4 of those of imported products, and many customers are now gradually replacing their flow meters with ours
For gas measurement, due to density issues, few products can achieve 0.5; considering that rotors could be used as a fallback, here are several options: 1. For a 3\" vortex street, the measurable range for H2 is 600–6000 NM3/H, with an accuracy of 1.0. 2. Gas turbines work too; we have used them for measurement as well. 3. An orifice plate will work as well; DP=16 KPA, flow range of 5000 NM3/H, orifice ratio of 0.486. It needs to be calibrated outside, and the required straight pipe sections are available, ensuring an accuracy of 1.0. 4. For thermal methods, it depends on the composition and changes of the gas; I’m not familiar with this, so I’d ask the experts on this forum. Mass flow meters are not recommended, mainly because the low density of H2 results in poor accuracy (it may be worse than vortex flow meters). From personal experience, mass flow meters are not necessary for H2 with a weight of less than 20 KG. @jiaguoyun
Generally, hydrogen is relatively clean; it is recommended to use imported turbines due to their high precision, but the pressure inside the pipes should not change drastically. You can also try an adjustable flow meter; it’s better than orifice plates. Vortex flow meters are not recommended, as few manufacturers can produce them well. I would like to remind you kindly that cone flow meters must never be used with high-pressure hydrogen; there have been incidents in which the cone fell into the pipeline, accelerated rapidly, penetrated the elbow, and caused an explosion.
This post was last edited by qugd on 2015-11-6 21:53. As for process measurement, mass flow meters are not recommended. Firstly, mass flow meters are expensive. Furthermore, for process metering, there is absolutely no need to use flowmeters with such high precision; some people, in an attempt to sell mass flowmeters, hardly know what to advertise. If the flow rate is relatively stable with little variation, an orifice plate or a balanced flow meter can also be used. If the flow rate varies significantly, a vortex flow meter can be used. For hydrogen measurement, these two types of flowmeters require virtually no maintenance.
It is recommended to use vortex flow meters. In your case, the pressure is 0.5 MPa and the flow rate is relatively low; for a pipe of 100 diameter, a flow meter with a capacity of 80 might be sufficient. In our company, vortex flow meters are used for the hydrogen feed to the hydrogenation tower in the case of hydrogen peroxide processing. Our flow rate is less than 4 kilograms, which is higher than yours. The manufacturer required a flow rate of over 6 kilograms for measuring hydrogen, and we were worried that the flow meter wouldn’t work properly. However, it functioned normally once operation started, but temperature and pressure compensation is necessary – this should be done directly on the DCS system
Our company uses many electromagnetic flowmeters; there are also a few more Kent rotor flowmeters, V-type flowmeters, and many others as well