Due to the compressibility of gas, its flow measurement is more complicated than that of liquid. The output signal of vortex flowmeter is not only related to the input signal, but also related to the gas density, and the gas density is temperature and pressure (referred to as temperature and pressure) The function. Therefore, temperature and pressure compensation problems generally exist in gas flow measurement.
The density of vapor is not only related to temperature and pressure, but also related to humidity. In recent years, new types of vortex flowmeters have emerged, making the temperature and pressure compensation of gas flow measurement simple and reliable, thereby improving the measurement accuracy.
Temperature and pressure compensation Vortex flowmeter classification of the medium during measurement
1. When measuring gas, temperature and pressure are required to be compensated at the same time; the gas is generally settled at the standard volume flow rate. Because the volumetric flow rate of gas changes when temperature or pressure changes, the flow rate will change.
2. When measuring superheated steam, temperature and pressure compensation are required at the same time; steam is generally settled by mass flow. Because any one of temperature or pressure changes, the density of the steam will change, and the mass flow will also change.
3. When measuring saturated steam, single temperature compensation or single pressure compensation is required. The density of saturated steam has a fixed correspondence with temperature or pressure (saturated steam density table). Knowing any of them can determine the density of saturated steam.
Why does the vortex flowmeter have no flow display?
1. Confirm whether the vortex flowmeter is connected to the power supply, check whether the output voltage of the power circuit board is normal, or try to replace the entire power circuit board to judge whether it is good or bad.
2. Check whether the cable is in good condition and whether the connection is correct.
3. Check the direction of steam flow and whether the liquid in the tube is full. For those capable of forward and reverse measurement, it can be measured if the directions are inconsistent, but the set display flow does not match the forward and reverse directions and must be corrected. If the workload of dismantling the sensor is large, you can also change the direction of the arrow on the sensor and reset the display instrument symbol. The underflow of liquid in the pipeline is mainly caused by the improper installation position of the vortex flowmeter. Measures should be taken during installation to avoid causing the liquid in the pipeline to be unfilled.
4. Check whether the electrode on the inner wall of the transmitter is covered with a liquid scarring layer. For measuring steam that is easy to scar, it should be cleaned regularly.