Regarding the compensation issue for steam flow rate
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I would like to ask everyone: since there is no direct relationship between the temperature and pressure of superheated steam, dual compensation based on both temperature and pressure is usually employed when measuring flow rate. Since there is a corresponding relationship between saturated steam temperature and pressure, it is sufficient to choose one of them as the compensation variable; whether it is the compensation temperature or pressure, it is all done in order to obtain the density. Are my views on the above two points correct? If, during actual production, no compensation is applied for the saturated steam, then could I manually set a density value in the DCS (as long as the saturated gas conditions remain stable, this density value can be considered fixed) to use for direct calculations? Is that possible?
Your idea is correct; if the temperature or pressure of the saturated steam remains constant, a fixed density can be used for the calculations
Yes, your idea is correct. If the requirements aren’t very high, this approach works fine. Some field instruments also provide static compensation, with the output being the mass flow rate directly
The original poster has a good idea. There is no one-to-one relationship between superheated steam and temperature and pressure; therefore, simultaneous compensation for temperature and pressure is necessary ； The density of saturated steam has a one-to-one relationship with temperature and pressure; therefore, compensation for only one of temperature or pressure is sufficient. When the temperature variation is not significant, a fixed density value can be entered to calculate the mass flow rate of steam. It is best for the poster to use a vortex flow meter with temperature or pressure measurement functions to directly measure the mass flow rate of saturated steam.