Why do steam vortex flowmeters need temperature and pressure compensation for measurement?

Steam vortex flowmeters are widely used in industrial trade settlement and flow measurement due to their simple structure, easy installation, wide measurement range, and small pressure loss. Under different working conditions, steam density will change with changes in temperature and pressure. Therefore, it is necessary to introduce the temperature and pressure of the measured gas into the flow measurement system during measurement, so that the system can perform temperature and pressure compensation through conversion to achieve accurate measurement. The meaning of temperature and pressure compensation is to convert the measurement results that are not under standard conditions into the corresponding measurement results under standard conditions, ensuring that the measurement results at different points are at the same scale, which is convenient for comparison and statistics.

Steam vortex flowmeter temperature and pressure compensation generally uses on-site installation of pressure and temperature sensors, and the pressure, temperature, and flow data are uploaded to the EF-II/TCP series intelligent flow totalizer to calculate the standard conditions.

Steam can be divided into superheated steam and saturated steam according to the characteristics of various types of steam pressure and temperature.

• When measuring superheated steam, temperature and pressure need to be compensated at the same time; steam is generally settled in terms of mass flow. Because either temperature or pressure changes, the density of the steam changes and the mass flow rate changes accordingly.

• When measuring saturated steam, single temperature compensation or single pressure compensation is required. The density of saturated steam is proportional to either temperature or pressure. Knowing either of these, the density of saturated steam can be determined.

  

In addition, the steam vortex flowmeter can also be used for the measurement of gases and some liquids. Temperature and pressure compensation is also required during measurement.

• When measuring gas, temperature and pressure need to be compensated at the same time; gases are generally settled based on standard volume flow rates. Because the volume flow rate of the gas changes when the temperature or pressure changes, the flow rate will change.

• When measuring liquids, pressure compensation is generally not required. Below 5MPa, only the influence of temperature is generally considered. Temperature compensation is required for accurate measurement. In general measurements, you do not need to use any compensation; when measuring some hydrocarbons (such as crude oil), simultaneous compensation of temperature and pressure is generally required.