存在的问题主要有：①指示长期不准；②始终无指示；③指示大范围波动，无法读数；④指示不回零；⑤小流量时无指示；⑧大流量时指示还可以，小流量时指示不准；⑦流量变化时指示变化跟不上；⑧仪表K系数无法确定，多处资料均不一致。 The main problems of the vortex flowmeter are: ① the instruction is not accurate for a long time; ② there is no instruction all the time; ③ the instruction has a wide range of fluctuations and cannot be read; ④ the instruction does not return to zero; ⑤ there is no instruction when the flow is small; , The indication is not accurate when the flow is small; 指示 the change of the indication cannot keep up when the flow changes; ⑧ the K coefficient of the instrument cannot be determined, and many data are inconsistent.
障碍处理的归纳大全具体归纳为以下10点：1)、选型方面的问题。 The summary of vortex flowmeter obstacle handling is summarized in the following 10 points: 1) Problems in selection. Some vortex sensors have a larger size in the selection of the caliber or after the design selection due to changes in process conditions. The actual selection should choose the smallest caliber as possible to improve the measurement accuracy. The main reasons for this are the same as Questions ①, ③, ⑥ are related. For example, a vortex street pipeline is designed to be used by several equipments. Because the process equipment is sometimes not used, the current actual flow rate is reduced. The actual use causes the original design to be selected too large, which is equivalent to increasing the measurable flow rate. At the lower limit, the indication cannot be guaranteed when the process flow is small, and it can be used when the flow is large, because it is sometimes too difficult to rebuild. Changes in process conditions are only temporary. Can be combined with parameter re-tuning to improve the indication accuracy. 2) Problems in installation. The main reason is that the length of the straight pipe section in front of the sensor is not enough, which affects the measurement accuracy. The reason for this is mainly related to problem ①. For example, the straight pipe section in front of the sensor is obviously insufficient. Because FIC203 is not used for measurement, it is only used for control. Therefore, the current accuracy can be equivalent to degraded use 3), the reason for parameter setting direction. Due to the wrong parameter, the instrument indication is wrong. The parameter error causes the secondary meter full-scale frequency to be calculated incorrectly. The main reason for this is related to problems ① and ③. The full-scale frequency is similar, which makes the indication inaccurate for a long time. The full-scale frequency calculated by the actual full-scale frequency makes the indication fluctuate widely and cannot be read. The inconsistency of the parameters on the data affects the final determination of the parameters. Re-calibration combined with mutual comparison determined the parameters and solved this problem. 4), secondary instrument failure. This part has many faults, including: once the instrument circuit board is disconnected, the range setting has a single bit display that is bad, the K coefficient setting has a single bit display that is bad, making it impossible to determine the range setting and the K coefficient setting. Part of the reason is mainly related to problems ① and ②. The problem can be solved by repairing the corresponding faults 5), the problem of four-way line connection. Some circuits look good on the surface of the circuit. Carefully check that some connectors are actually loose and cause the circuit to be interrupted. Although some connectors are tightly connected, due to the problem of the auxiliary line, the fastening screws are fastened to the wire cover, which also makes the circuit. Interruption, this part of the cause is mainly related to problem ②. 6). The connection between the secondary instrument and the subsequent instrument. The mA output circuit of the secondary meter is interrupted due to a problem with the subsequent meter or the maintenance of the subsequent meter. For this type of secondary meter, this part of the cause is mainly related to problem ②. Especially for subsequent recorders, if the recorder is damaged for a long time and cannot be repaired, it is necessary to pay attention to shorting the output of the secondary instrument. 7) The loop of the secondary instrument's flat shaft cable always causes no indication. Due to the long-term operation and the influence of dust, the flat-axis cable is faulty. The problem can be solved by cleaning or replacing the flat-axis wire. 8) For the problem ⑦ The main reason is that the secondary meter display meter head ’s coil fixing screw is loose, which causes the meter head to sink, the pointer and the case friction is large, and the action is not working. By adjusting and refixing the meter head, the problem is solved accordingly. 9), the use of environmental issues. Especially the sensor part installed in the ground well, due to the high ambient humidity, the circuit board gets wet. This part of the reason is mainly related to problems ② and ②. Through corresponding technical reform measures, some sensors with high ambient humidity have been re-separated from the probe part and the conversion part, and a separate sensor has been used instead, which has improved the working environment. This part of the instrument has been running well. 10), because the on-site adjustment is not good, or because of actual changes after adjustment. Due to poor on-site vibration and noise balance adjustment and sensitivity adjustment. Or due to the change of the on-site situation after a period of operation after the adjustment, the indication problem is caused. This part of the cause is mainly related to problems ④ and ⑤. Use an oscilloscope, coupled with the process running conditions, readjust.
应用效果是产品性能、选型、安装的综合反映。 The application effect of the vortex flowmeter is a comprehensive reflection of product performance, selection and installation. An analysis of several problems that are easy to be neglected in the application is made to attract attention and attention. (1) In the design and selection phase, the appropriate vortex street diameter must be selected according to the actual process parameters of the steam, and the pipe size is only for reference. Experience shows that there is often a large margin in the design of pipelines, and the size of steam pipelines is generally large. If the vortex street diameter is selected according to the original pipeline, it will often cause the accuracy to drop (small flow loss) and even the consequences of being unable to measure; The diameter of the vortex street selected by the parameter often has a lower gear. At this time, a concentric shrink tube is required to install the vortex street. (2) Installation must be strictly in accordance with construction specifications. For example, the length of the front and rear straight pipe sections must meet the technical requirements of the vortex flowmeter. The centerline of the vortex instrument body is coaxial with the centerline of the straight straight pipe. The gasket cannot extend into the pipe. This can prevent the flow area from being covered, Velocity distribution is distorted, and the flow field is disturbed to cause measurement errors. The measurement section of the steam pipeline is guaranteed to be free of condensate. For newly installed process pipelines, the vortex street must be removed before purging, and it can be replaced after being cleaned. (3) The electrical wiring must be standardized, and the waterproof and high temperature protection measures on site must be in place. For example, the optimal height of the thermal insulation layer on the meter body cannot be higher than half of the bracket of the meter head, so that the thermal insulation part (lower part) in the bracket can prevent heat radiation, and the non-insulation part (upper half) can prevent Heat is transferred to the meter head; when the pipe is horizontal, the meter head should be placed as horizontally as possible to minimize the impact of hot air on the preamp electronics. The core of this measurement system is a differential switch capacitive vortex flowmeter, which plays a decisive role in the success of the measurement. Several years of application practice shows that this capacitive vortex street works stably and reliably, and has strong anti-vibration interference. There is no sensitivity to vibration of the stress type vortex flowmeter. The measurement data is credible and fair. There is also no such problem that the stress type vortex street is often damaged by lightning; the structure is sturdy, there are no moving parts, there are no wear and block problems, no maintenance is required, and the use cost is low; high sensitivity, wide range ratio, and reduced small flow loss ; The instrument has high accuracy (up to 0.5%), and it will hardly change in long-term operation.