Vortex flowmeter is mainly used for flow measurement of medium fluid in industrial pipelines. It is characterized by convenient installation and maintenance, high cost performance and wide application range. Vortex street flowmeter is used in the measurement and control of superheated steam, saturated steam, compressed air and general gas, water and liquid in petroleum, chemical, metallurgical, thermal, textile, paper and other industries. The volume of saturated steam and superheated steam is greatly affected by temperature and pressure. Now let's share with Shunda Flowmeter the realization method of pressure stabilization compensation for vortex flowmeter.
1. One time compensation implementation method
First, determine the working parameters of steam - temperature and pressure. The vortex flowmeter determines the density of steam under working condition according to the working parameters, and calculates the density of steam as the density of steam during future flow measurement. In the work, the actual change of steam will not be compensated or corrected, which is the so-called one-time calculation compensation method.
If the operating parameters of steam are consistent with the design set values during operation, the accuracy of steam flow measurement can be guaranteed. If the parameters are deviated or even greatly deviated under actual working conditions, the deviation of measurement results may be very large.
The one-time compensation method, which was adopted in the early development of automatic detection technology, has a large error in measurement results and can be used as a rough measurement. Such design means are still used in the widely popular design manual of flow throttling device.
2. Realization method of online density compensation
With the wide application of microelectronics technology in instruments. The calculation function, compensation and correction function, accumulation function, historical data storage function, digital filtering function, output function, digital communication function, etc. of vortex flowmeter can be easily realized. Online density compensation has become an essential basic function of steam metering instruments and is widely used. The following describes the classification of steam density compensation:
{1} Saturated steam online density compensation.
The vortex flowmeter can realize integrated temperature and pressure compensation, and there is a strict one-to-one correspondence between the temperature and pressure of saturated steam. The density of saturated steam can be a single function of its temperature or pressure. According to the temperature value or pressure value of saturated steam, the real-time density value can be obtained by the table lookup method or formula calculation method (IFC1967 or IAPW-1997).
In flow measurement, vortex flowmeter can be realized by temperature compensation or pressure compensation flowmeter. Select the flowmeter with temperature compensation function. Turn on the temperature sensor of the flowmeter to detect the measured steam temperature in real time, so as to obtain the corresponding density value.
{2} On line density compensation of superheated steam
Superheated steam is a kind of steam with special quality obtained by reheating saturated steam. It breaks the strict one-to-one correspondence between the temperature and pressure inherent in saturated steam. Superheated steam can be regarded as a single medium in the flow measurement process of vortex flowmeter. The density of superheated steam is a comprehensive function of its temperature and pressure. When ordering vortex flowmeter, temperature and pressure compensation type shall be selected. In actual use, the temperature and pressure sensors are simultaneously turned on to measure the steam temperature and pressure in real time. The density value can be accurately calculated according to the superheated steam density meter or density calculation formula.
As a professional R&D flowmeter manufacturer, Hesunda flowmeter manufacturer has been adhering to the production concept of creating a brand with quality and seeking development with brand for several years, persevering, overcoming difficulties, and constantly developing new technologies and products to provide customers with reliable quality products that meet their needs, At the same time, we have also established long-term cooperative relations with many production enterprises, and all colleagues of Shunda look forward to sailing together with you.
