Ultrasonic flowmeter uses the electronic principle to measure the flow meter. Although it has its own verification procedure, because it has the same usage management mode as the tap water industry measurement, it puts its performance requirements, measurement accuracy, verification cycle, etc. into the cold water meter. In the meantime, it has become more standardized. Since then, the use of large-caliber ultrasonic flowmeters has normative documents in the water industry.
Ultrasonic flowmeter (ultrasonic water meter) Because the measurement principle is different from electromagnetic water meter, its accuracy is different. How to choose an ultrasonic flowmeter with superior performance and precision:
The user flow range is used to determine the type, diameter, temperature, medium, etc. of the ultrasonic flowmeter, especially considering the common flow rate and the starting flow rate. The purpose is to ensure the water supply quantity, accurately measure and reduce the leakage rate. When using the water meter, the user's water meter Commonly used traffic generally cannot exceed the common flow value specified by the product.
Different flow rate to determine the diameter of the flow meter can meet the measurement range.
Different user environments.
Also consider the working pressure, the structure of the flow certificate, the form of the converter (whether bidirectional flow, current, pulse, communication interface, data storage) and the length of the connecting cable.
The performance and accuracy of the ultrasonic flowmeter are selected.
Users can learn more about the peers who are already using the ultrasonic flowmeter, to see the effect of their use, the accuracy of the measurement.
At present, industrial flow measurement generally has problems of large diameter, large flow, small diameter, small flow, high temperature liquid, and gas measurement. This is because the general flowmeter will bring manufacturing and transportation as the diameter of the measuring pipe increases. The difficulty of the above, the advantages of increased cost, increased energy loss, and inconvenient installation, ultrasonic flowmeters can be avoided. The German FLEXIM ultrasonic flowmeter measures diameters from 6mm to 6500 mm, from a few meters wide open channels, culverts to 500m wide rivers.
Maintenance of the turbine flowmeter sensor section:
1. Before the sensor is installed, use the mouth to blow or hand the impeller to make it rotate quickly to see if there is any display. Install the sensor when there is display. If there is no display, check the relevant parts and troubleshoot.
2. When using, keep the measured medium clean and free of impurities such as fibers and particles.
3. When the turbine flow sensor starts to use, the sensor should be slowly filled with the medium, and then the outlet valve should be opened (the valve should be installed at the back end of the flowmeter). It is forbidden to be impacted by the high-speed fluid when the sensor is in the mediumless state.
4. The maintenance period of the turbine flow sensor is generally half a year. When cleaning and cleaning, please be careful not to damage the parts in the measuring chamber, especially the impeller. Please be optimistic about the positional relationship between the guide and the impeller during assembly.
5. When the turbine flow sensor is not in use, the internal medium should be cleaned, and after drying, a protective cover is added at both ends of the sensor to prevent dust from entering, and then stored in a dry place.
6. The filter used in the turbine flowmeter should be cleaned regularly. When not in use, the internal medium should be cleaned. As with the sensor, add a dust jacket and store it in a dry place.
However, since the volume of condensed water in the wet steam is relatively small, the flow of excess water in the ascending pipe often appears as an annular flow structure, but when the amount of water is particularly large, it also appears as a ring with fibers. Flow structure. Among them, the fibrous fluid is actually a condensed water. Flow in a vertically descending pipe: In a vertically descending pipe, the structure of the gas-liquid two-phase flow is similar to that of a vertically ascending flow, but differs not only in the opposite flow direction but also in the case of the same average flow velocity. The flow rate of the liquid in the vertical drop pipe is much faster than the flow rate of the liquid in the vertical rise pipe.
Second, steam vortex flowmeter measurement considerations
Vortex flowmeters measure steam. Accurately arrange the steam traps accurately: People have long discovered that when the steam has more water, the vortex flowmeter will have a "leakage pulse" phenomenon, that is, in the case of a stable steam flow rate, the vortex flow It should have a stable pulse output proportional to the flow rate. But sometimes it is found that the output pulse of the meter is inexplicably less. The distribution of the output pulse recorded on the two-dimensional coordinates can also be clearly seen. The pulse that should be approximately evenly distributed is one less at a place. Pulses, in severe cases, are a lot less pulses, and in the worst case, there are no pulses at all. This may be related to the formation of a vortex column by impinging on a large volume of droplets having a non-uniform distribution on the vortex generator.