The main sources of measurement errors of V-cone flowmeters are caused by improper installation, untimely maintenance, or changes in process system operating parameters. Today I will summarize the faulty operation of the V-cone flowmeter.
现场安装不规范主要可能有下面几个原因：工艺管道前后直管段不足，造成流体的不稳定，影响测量精度；安装方向有问题，当然了，这个问题基本是不会发生的，除非是现场安装的失误造成的；测量蒸汽的时候，冷凝装置降温不彻底，安装高度不等2，其次就是二次仪表的误操作问题,V锥流量计现场使用的时候，都要配备差压变送器才能正常使用，所以，差压变送器性能和安装的正确与否直接影响V锥流量计的整体精度。 1. The first is the irregular installation. The irregular installation of the V-cone flowmeter may be caused by the following reasons: insufficient straight pipe sections before and after the process pipeline, causing fluid instability and affecting measurement accuracy; there are problems with the installation direction, of course, this The problem basically will not happen unless it is caused by the error of field installation; when measuring steam, the cooling of the condensing device is not completely cooled, and the installation height is different2, followed by the misoperation of the secondary meter, V cone flowmeter field use When it is used, a differential pressure transmitter must be equipped for normal use. Therefore, the performance and installation of the differential pressure transmitter directly affect the overall accuracy of the V-cone flowmeter. The V-cone flowmeter still has successful operation experience in measuring mixed fluids, but it is necessary to pay attention to the corrosion protection of the differential pressure transmitter and periodically open the drain valve. 3. At the end, the pressure guiding tube is blocked or leaking. When measuring viscous and crystalline medium, the pressure guiding tube and the shut-off valve are often blocked due to heat tracing and other reasons, so that the differential pressure input to the differential pressure transmitter changes. Measurement error. Elimination methods are to conduct inspections on time, clean the sewage or clean with a hand pressure pump. When measuring high-pressure or corrosive media, pressure leaks or joints often leak, causing pressure loss and differential pressure deviation. The solution is to conduct inspections on time and plug the loopholes. Through the above description, our on-site maintenance technicians can easily find the fault of the V-cone flowmeter and reduce the economic loss on site.
技术特点： V cone flowmeter technical characteristics:
1. Low installation requirements: straight 0 ~ 3D straight pipe, rear 0 ~ 1D straight pipe section; 2. Wide range ratio: usually 10: 1, choosing the right parameter can achieve up to 50: 1; 3. Small pressure loss: The same β value, the pressure loss is 1/3 ～ 1/5 of the orifice plate; 4. Wear resistance: After the streamlined cone is throttled, a vacuum layer effect is generated on the surface of the cone, making the cone difficult to wear; 5. Not clogging Non-adhesion: The cone-shaped thorough purging design avoids the retention of residues, condensates or particles in the fluid; 6. Long-term stability is good: The β value can be unchanged for a long time and ensure accurate long-term measurement; 7. High accuracy : 0.5; 8. Good repeatability: better than 0.1%; 9. Signal stability: "Signal fluctuation" is 1/10 of the orifice flowmeter; 10. Wide range of β value: V cone flow sensor's unique geometry allows Has a wide range of β values; 11. Wide caliber range: DN25 ～ DN2000; 12. Measurable high temperature and high pressure medium: Working temperature up to 850 ℃, maximum pressure 40MPa; 13. Measurable dirty medium (coke oven gas, blast furnace gas) , Raw oil, residual oil, etc.); 14, can measure gas-liquid two-phase media (moisture, condensed water, etc.);
节流式差压流量计)和涡街流量计为核心流量计为主要丈量流量计。 Standard nozzles and classic venturi tubes, V-cone flowmeters ( throttled differential pressure flowmeters) and vortex flowmeters are the core flowmeters. And the throttling differential pressure flowmeter takes standard throttling device as the main application object. For example: standard orifice plate. In recent years, as a new type of differential pressure flowmeter, the V-cone flowmeter is slowly replacing the standard throttling device. When the V-cone flowmeter is used for field measurement, its specific advantages are mainly reflected in the following aspects: However, the V-cone flowmeter can reach 113 and ensure a measurement accuracy of 0.5. The high accuracy and wide range ratio greatly facilitate field measurement. 1 range is wide and the normal measurement range of the throttling device is 13 in this way. Saved some costs for the on-site process. The V-cone flowmeter can also adapt to the load changes of steam in summer and winter. Conducive to improving measurement accuracy 2 linear differential pressure output. V cone flowmeter combined with multi-parameter differential pressure transmitter. Make the differential pressure signal output and flow have a linear relationship. Due to the variable area setting of the V-cone flowmeter, the requirement for 3 straight pipe sections is low. This makes it a measuring mechanism capable of high Reynolds numbers. Generally, straight pipe sections require pressure signals for straight pipe sections with a distance of 5D upstream and 3D downstream, and with the combination of computer technology and field measurement technology. The temperature signal is integrated into the differential pressure signal to compensate for the on-site differential pressure signal, so that it can accurately track the changes in fluid working conditions, even if it reflects the accurate value of the on-site fluid. There are some disadvantages, but the V-cone flowmeter is measuring steam . It is generally not suitable to use when the pressure on site is relatively high, because the cone of the V-cone flowmeter at this time will fall off due to the local pressure when measuring. Therefore, in places with high pressure, it is still necessary to choose a standard throttling device, and the device method is direct welding.