The steam orifice plate flow calculation is as follows; how to perform temperature and pressure compensation, and how to convert to standard conditions
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As shown in the steam orifice plate calculation sheet, the value calculated is the mass flow rate; it is obtained by using the density values at the design temperature and design pressure. I would like to ask everyone: 1. If one wants to perform thermal and pressure compensation, how should it be done? What formula should be used? 2. If you want to perform a conversion to standard conditions, which formula should be used? I also looked up a lot of information, but I didn’t quite understand it. Some say the ideal gas law can be used, while others say it is necessary to consult tables to determine the steam temperature at actual temperatures and pressures; still others argue that saturated steam and superheated steam are different from each other. Could you please explain in detail the principles and calculation processes of temperature and pressure compensation as well as conversion to standard conditions? Thank you!
The concept of standard conditions refers to a temperature of 0 degrees or 20 degrees at an atmospheric pressure of 1 atmosphere. Steam doesn’t have such a thing as standard conditions. So mass flow rate is useful; there is no need to switch to volume flow rate. Replacing it is actually troublesome. General gas compensation is not recommended, as it may result in some errors in the calculations related to steam.
Are you saying that we can just use the formula from the calculation sheet? What if the actual temperature and pressure of the steam are different from those in the calculation sheet?
For voltage stabilization compensation, it is necessary to determine the actual density using a lookup table, calculate the ratio to the designed density, and then take the square root. Calculate the compensation coefficient and multiply it by the uncompensated flow rate. That is, the accurate flow rate. This is our calculation method for balanced orifice plates. Our formula is different from this; you can see that their calculation manual requires the density ρ.
Steam is not an ideal gas; it is necessary to calculate its actual density and then make adjustments accordingly. Come and look at this book, page 391.
This post was last edited by hfrs on 2021-4-16 09:12: Shame on you! Is it wrong for people to put in effort to find information and earn some wealth? Isn’t it too despicable of you to do this!
Take a look at this connection: Approaches and methods for temperature and pressure compensation in steam flow measurement
This post was last edited by liubingfan on 2021-4-16 at 17:48. What if it’s nitrogen? Can the ideal gas law be used to compensate for that? Equation 1: P1*V1/T1 = P2*V2/T2 (Subscript 1 refers to the design temperature, while subscript 2 refers to the actual temperature). Equation 2: See attached diagram. Which equation should be used? Are there any standards to refer to regarding compensation?