Vortex flowmeter is mainly used to measure the flow of medium fluid in industrial pipeline, such as gas, liquid, vapor and other media. Its characteristics are small pressure loss, wide range and high accuracy. It is almost independent of the parameters such as fluid density, pressure, temperature and viscosity when measuring volume flow rate under working conditions. No mechanical parts, so high reliability, small maintenance. Instrument parameters can be stable for a long time. The instrument adopts piezoelectric stress sensor, which has high reliability and can work in the range of - 20 ~250 ~C. It has analog standard signal and digital pulse signal output. It is easy to be used with computer and other digital systems. It is an advanced and ideal flow meter.
First, the main problems are as follows: 1) long-term inaccuracy of indicators; 2) no instructions; 3) large-scale fluctuation of indicators, unable to read; 4) no return to zero; 5) no instructions when small flow; 5) large flow indicators can also be used, small flow indicators are inaccurate; 5) flow indicators can not keep up with changes; 5) instrumentation K coefficient is uncertain, and many data are inconsistent.
The problems of type selection. In order to improve the accuracy of measurement, some vortex street sensors should choose as small as possible because of the change of technological conditions after the design and selection. The main reasons for this are related to the following questions: (1), (3) and (3). For example, a Vortex Street pipeline is designed to be used by several equipment. Because some equipment in the process is sometimes not used, the actual flow is reduced. The actual use of the pipeline results in the excessive size of the original design, which is equivalent to raising the lower limit of measurable flow. When the flow rate is small, the indication of the pipeline can not be guaranteed, and when the flow rate is large, it can also be used, because it is sometimes difficult to reconstruct it. The degree is too high. The change of technological conditions is only temporary. It can be combined with parameter re-tuning to improve the accuracy of indication.
Installation problems. 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 main reason in this respect is related to the problem (1). For example, the straight pipe section in front of the sensor is obviously inadequate. Because FIC203 is not used for metering and is only used for control, the current accuracy can be used as a degraded one.
The reason of parameter setting direction. The errors of parameters lead to errors in instrument indication. The errors of parameters lead to errors in calculating the fullness frequency of secondary instruments. The reasons in this respect are mainly related to problems (1) and (3). Full-degree frequencies are similar to each other, which makes the indication inaccurate for a long time. Full-degree frequencies calculated by actual full-degree frequencies make the indication fluctuate in a large range and can not be read. The inconsistency of parameters in the data affects the final determination of parameters. Finally, the parameters are determined by re-calibration and comparison, which solves this problem.