的耐高温及抗振动性能，我公司新近开发出了dx LU改进型涡街流量传感器，因其独特的结构和选材使该传感器可在高温（350℃）、强振动（≤1g）的恶劣工况下使用。 In order to improve the high temperature resistance and vibration resistance of the vortex flowmeter , our company has recently developed an improved dx LU vortex flow sensor. Due to its unique structure and selection of materials, the sensor can ≤1g) Use under severe conditions. Vortex flowmeter is a new type of flowmeter for measuring fluid flow in closed pipes based on the Carmen vortex principle. Because of its good medium adaptability, it can directly measure the working volume flow of steam, air, gas, water, and liquid without temperature and pressure compensation. Equipped with temperature and pressure sensors, it can measure standard volume flow and mass flow, which is throttling. The ideal replacement for the flow meter.
1. Selection issues. 的传感器在口径选型上或者在设计选型之后由于工艺条件变动，使得选择大了—个规格，实际选型应选择尽可能小的口径，以提高测量精度，这方面的原因主要同问题①、③、⑥有关。 Some vortex flowmeter sensors have a larger size when selecting a caliber or because of process conditions changes after design and selection. The actual size should be selected as small as possible to improve measurement accuracy. The reasons are mainly related to problems ①, ③, ⑥. 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 caused the original design to be too large, which is equivalent to increasing the measurable flow rate. 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. Installation problems. 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. Since FIC203 is not used for metering, it is only used for control, so the current accuracy can be used equivalent to degraded use. 3. Reason for parameter setting direction. Due to the wrong parameters, the meter indication is incorrect. 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 was resolved by fixing the corresponding fault. 5, four-way line connection problems. 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. Due to problems with subsequent instruments or maintenance of subsequent instruments, the MA output circuit of the secondary instrument is interrupted. For this type of secondary instrument, 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. There is no indication on the circuit due to the secondary instrument flat axis cable failure. 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, it is mainly due to the looseness of the screw on the coil of the secondary meter display meter head, which causes the meter head to sink, the pointer to the watch case to have a large friction, and the action 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. Due to poor on-site adjustment, or due to changes in the actual situation after adjustment. Due to the on-site vibration and noise balance adjustment and sensitivity adjustment is not good. 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. In practical applications, the maximum flow rate is often much lower than the upper limit value of the meter. As the load changes, the minimum flow rate is often lower than the lower limit value of the meter. The meter is not working in its optimal working section. One problem is usually to reduce the diameter at the measurement site to increase the flow velocity at the measurement site, and choose a smaller diameter instrument to facilitate the measurement of the instrument, but this method of diameter reduction must have a straight length of 15D or more between the reducer and the instrument. Pipe sections are rectified, making processing and installation inconvenient. The LGZ variable diameter rectifier developed by our company has a circular arc shape. It has multiple functions of rectifying, increasing the flow rate and changing the flow rate distribution. Its structure size is small, only 1/3 of the inner diameter of the process tube. It is integrated with the vortex flowmeter. Not only does not need to add another straight pipe section, it can also reduce the requirements for the straight pipe section of the process pipe, and the installation is very convenient. For the convenience of use, the battery-powered local display-type vortex flowmeter uses micro-power high-tech. It can be operated continuously for more than one year using lithium battery power, which saves the procurement and installation costs of cables and display instruments. It can display instantaneous flow rates, Cumulative flow, etc. The temperature compensation integrated vortex flowmeter also has a temperature sensor, which can directly measure the temperature of the saturated steam and calculate the pressure, thereby displaying the mass flow of the saturated steam. Temperature and pressure compensation integrated type with temperature and pressure sensors for gas flow measurement can directly measure the temperature and pressure of the gas medium, thereby displaying the standard volume flow of the gas.
输出信号不稳定的原因 Causes of Instability of Vortex Flowmeter Output Signal
qVn, qV--respectively the volume flow under standard conditions (0oC or 20oC, 101.325kPa) and working conditions, m3 / h;
Pn, P--absolute pressure under standard conditions and working conditions, Pa;
Tn, T-the thermodynamic temperature under standard conditions and working conditions, K;
Zn, Z--respectively the gas compression coefficients under standard conditions and working conditions.
It can be seen from the above formula that the pulse frequency signal output by VSF is not affected by the fluid physical properties and composition changes, that is, the meter coefficient is only related to the shape and size of the vortex generator and the pipeline within a certain Reynolds number range. But as a flow meter needs to detect the mass flow in the material balance and energy measurement, the output signal of the flow meter should monitor the volume flow and fluid density at the same time. The fluid properties and components have a direct impact on the flow measurement.
不适宜安装在强振动的场合是应用者广为熟知的，但在磁场频繁变化的场合，涡街流量传感器会测出高于正常值的信号输出。 1. Vortex flowmeters are not suitable for installation in places with strong vibrations, which are widely known by users. However, in situations where the magnetic field changes frequently, the vortex flowmeter will measure a signal output higher than normal. Practice has proved that in a scene where no gas flows, when the vortex flow sensor is in a changing magnetic field, the vortex flow sensor will sense an error signal and output it when the magnetic field changes. When the change is over, the meter is in a stable magnetic field. The meter will output a normal signal. 2. Because the coke oven gas has many impurities, it is easy to crystallize, and the impurities are condensed on the sensor head, which causes measurement inaccuracy. When the temperature increases, the impurities evaporate, the sensitivity increases, and the signal increases; on the contrary, it decreases. As a result, data is unstable. 3. Due to the high temperature and high humidity of the coke oven gas when leaving the factory, there will be moisture in the gas transportation process. The gas flow drives the water back and forth to form a pulsating flow. When the vortex flow sensor is in this fluid state, the output data is suddenly large or small, and it cannot reflect the production status at all. 4. The crimping line is not solid during the instrument wiring process, which causes the signal to be intermittent during transmission. 5. The ground wire of the instrument does not meet the requirements of the specification, so that the 50Hz interference in the strong current enters. When the normal signal is higher than 50Hz, a normal signal is output, otherwise an error signal is output.