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Description of the problems that occur during the use of the vortex flowmeter

Vortex flowmeters are mainly used for flow measurement of industrial pipeline media fluids, such as gases, liquids, vapors and other media. It is characterized by small pressure loss, large measuring range and high precision. It is almost unaffected by parameters such as fluid density, pressure, temperature and viscosity when measuring the volume flow rate. No moving mechanical parts, so the reliability is high and the maintenance is small. Instrument parameters can be stable for a long time. The instrument uses a piezoelectric stress sensor with high reliability and can work in the operating temperature range of -20 ° C ~ +250 ° C. There are analog standard signals and digital pulse signal outputs, which are easy to use with digital systems such as computers. It is a relatively advanced and ideal flow meter.

First, the main problems are: 1 indicates long-term inaccuracy; 2 has no indication at all; 3 indicates large-scale fluctuations, can not read; 4 indicates no return to zero; 5 no flow when there is no indication; 8 large flow indication is OK, When the flow rate is small, the indication is inaccurate; when the flow rate changes, the indication change cannot keep up; 8 the K factor of the meter cannot be determined, and the data of many places are inconsistent.

The problem of selection. Some vortex sensors are selected on the caliber or after the design and selection, because the process conditions are changed, so that the selection is larger — the actual selection should be as small as possible to improve the measurement accuracy. Related to questions 1, 3, and 6. For example, a vortex pipeline is designed for use by several equipment. Because some of the equipment is not used sometimes, the actual actual flow is reduced. The actual design results in too large an original design, which is equivalent to an increase in measurable flow. The lower limit, when the process pipe is small, the indication is not guaranteed. When the flow is large, it can be used, because it is sometimes too difficult to rebuild. Changes in process conditions are only temporary. The re-tuning of the parameters can be combined to improve the indication accuracy.

Installation issues. The main reason is that the length of the straight pipe in front of the sensor is not enough, which affects the measurement accuracy. The reason for this is mainly related to the problem 1. For example, the straight pipe section in front of the sensor is obviously insufficient. Since the FIC203 is not used for measurement, it is only used for control, so the current accuracy can be used equivalent to the downgrade.

The reason for the parameter setting direction. The instrument is incorrectly indicated due to a parameter error. The parameter error makes the secondary instrument full-scale frequency calculation error, and the reason for this is mainly related to questions 1, 3. The full-scale frequency is similar, which indicates that the long-term inaccuracy is indicated. The full-scale frequency of the actual full-scale frequency and large-dry calculation indicates that the range is fluctuating and cannot be read. The inconsistency of the parameters on the data affects the final determination of the parameters, and finally passes. Recalibration combined with mutual comparison to determine the parameters solves this problem.

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