Flow temperature and pressure compensation formula

Formula: Actual flow rate = P3 * SQRT(C1 / (273 + P2) * (P1 + 101) / C2)
Parameters: C1: Design temperature (K); C2: Design pressure (KPa); P1: Actual pressure (KPa); P2: Actual temperature (°C); P3: Flow rate before compensation. In fact, different manufacturers may use different formulas for temperature and pressure compensation

This depends on who the supplier of the DCS system is; one should ask them for clarification. Taking the Honeywell system that has been used in the past as an example: 1. It is necessary to select the correct data type; 2. Formulas that take temperature and pressure compensation into account must be used; 3. Just enter the tag numbers for pressure and temperature

Thermodynamic pressure compensation is actually derived from the ideal gas law; it applies only to ideal gases and introduces certain errors for real gases. It cannot be used for steam, as there are other formulas available

Could you explain the fourth floor more clearly?

When converting differential pressure signals into flow rate, it is related to the density of the fluid: Q = K * SQRT(ΔP/ρ), where K is a comprehensive coefficient. What is meant here is that, based on the differential pressure-to-flow rate conversion formula at the design temperature and pressure, the ideal gas law is used to calculate the fluid density, namely PV = nRT. This method can only be applied to fluids that can be treated as ideal gases, such as nitrogen and oxygen. Since water vapor cannot be considered an ideal gas, and there are many experimental data available regarding its properties, there are separate formulas for temperature and pressure compensation in the case of water vapor. Additionally, the compensation mentioned above applies only to gases; for liquids, separate methods must be employed, but the principle remains the same: calculate the fluid density under the operating conditions.

Flow compensation is indeed used for ideal gases. For water vapor, when it is saturated steam, its properties are similar to those of an ideal gas, so the same compensation formula can be applied； If it is superheated steam, a density calculation is required (there are specific formulas for density calculation that take temperature and pressure into account) in order to determine the mass flow rate.

Is it valid to say that the properties of saturated water vapor are approximately those of an ideal gas? It seems to go against experience; intuitively, the easier a gas is to liquefy, the more it deviates from ideal gas behavior.

Should the flow rates of the reactant gas and steam be corrected using different temperature and pressure formulas? Please give examples. Example: Flow, temperature, and pressure correction formula for CO+H2

Reply to 10# jxqxhj: Temperature and pressure? ? ? Temperature, pressure.