Large-scale water supply and drainage construction basically requires large-diameter flow measurement instruments, which are currently used in the selection of large-diameter flow meters for water supply and drainage.
Notes on the selection of electromagnetic flowmeters in tap water supply companies:
Large-scale water supply and drainage construction basically requires large-diameter flow measurement instruments, which are currently used in the selection of large-diameter flow meters for water supply and drainage. There are several types, mainly electromagnetic flowmeters, vortex electromagnetic flowmeters, orifice plates, vertical screw-wing water meters, and horizontal screw-wing water meters. Recently, electromagnetic flowmeters and ultrasonic flowmeters have a high application occupancy rate. Because they have better performance than traditional water meters, they have been widely used in production and life and have developed rapidly. This article mainly explains the selection and specific application of flow meters in our city's tap water industry. 2. How do water companies choose flow meters? Choosing the most suitable model is the key to maximizing the effectiveness of the flow meter. There are more than 100 manufacturers of large-diameter flow meters in our country, and there are countless models of flow meters on the market. Therefore, how to select a flow meter is a matter of great concern to us. Generally speaking, when selecting a flow meter, we need to check whether the flow meter has passed quality inspection and whether the usage conditions of the flow meter can meet the requirements of the actual installation. kind of requirement. Below we summarize some selection criteria for reference:
2. 1. When selecting, refer to the size of the water pipe. Water companies prefer electromagnetic flowmeters. When selecting flowmeters, they will first think of electromagnetic flowmeters. For flowmeters, for some large-scale projects, such as reservoirs and water diversion projects, Venturi tubes with relatively stable performance will be selected; large-diameter insertion flowmeters are generally not considered, and ultrasonic flowmeters are often chosen. 2.2 Relevant straight pipe section parameters when selecting flowmeters When selecting flowmeters, the parameters of the straight pipe section of electromagnetic flowmeters are generally above 5D, and the parameters of straight pipe sections of ultrasonic flowmeters are generally 10D-20D. 2.3 Consider the surrounding environmental conditions when selecting a flow meter. When selecting a flow meter, you need to conduct an on-site inspection to understand the on-site environmental conditions and select a suitable flow meter based on actual needs. 2.4 When selecting, refer to the general requirements of the control system. The electromagnetic flowmeter flowmeter, which is commonly used in the water supply industry, needs to be able to display the flow rate normally and output a flow signal. With the application of information technology in the tap water industry, the control system has become more scientific. There are also differences in the flow meter protocols equipped with different communication technologies. Therefore, our water companies need to refer to the usage requirements of the control system when selecting flow meters. 3 Flow meter detection and correction Electromagnetic flow meter flow meters also have their own service life. Long-term use will inevitably cause losses, resulting in certain usage errors in the flow meter measurement values. Therefore, water companies need to perform regular flow meter testing. Make corrections promptly if deviations occur. However, my country's relevant regulations on flow meter testing and calibration are not perfect enough. Our relevant units should issue some relevant policies as soon as possible and conduct trial operations point by point.
During the operation process, according to the problems that arise and the actual needs of different regions Make modifications and additions, and report the later revised regulations to relevant departments to form standards. Some flow meters are in useIf it has been running normally and the test results meet the requirements, it should be tested and calibrated every year. In particular, some flowmeters do not use standard tubes. During use, the inner tube diameter may become smaller, causing the flowmeter measurement data to deviate. actual data. What we call the flow meter problem caused by the smaller inner pipe diameter is generally difficult to check using portable ultrasonics. The main flow meter detection method is: comparative verification between the flow meter used by the water company and the standard flow meter. However, the standard flow meter is generally about 2-3 levels higher than the flow meter used by the water company. In addition, a flowmeter calibration device can be established to check the flowmeter's accuracy. You can also use the clean water tank volume calibration method for flow meter verification. 4. Management and maintenance of flow meters 4.1 Management of flow meters The management of flow meters mainly involves remote detection and correction of flow meters, flow meter data management and maintenance of flow meters. In recent years, with the rapid development of electronic technology, remote monitoring has developed into the current data remote transmission such as GPRS, GSM, and ADSL. When managing different types of flow meters, you need to pay attention to the following issues: First, you must be familiar with the specific operating instructions of the flow meter before using and maintaining the flow meter. Second point, the insertion turbine flowmeter should set the minimum z value and the maximum z value corresponding to the instrument coefficient K value. The third point is when debugging the electromagnetic flowmeter, the z value. It is necessary to enter the flow point corresponding to the correct instrument calibration coefficient GK value.
To use the ultrasonic flowmeter, it is necessary to measure the pipeline data, record the material, and measure it in the meter host. Then write the program code through the flowmeter host, and then proceed based on the results of the flow meter calculation. Installation of equipment and ensuring installation quality. 4.2 Maintenance of flow meters Precautions for maintaining different types of flow meters: First, for online flow meters, the surface of the meter must be clean, and attention must be paid to dust-proofing the flow meter. After saving the data information before identification, Only then can the flow meter maintenance and identification work be carried out. The second point is that after use, the portable flow meter needs to be carefully wiped and maintained, and the storage environment needs to be selected in accordance with regulations. The third point is to regularly check the sealing condition of the plug-in vortex flowmeter sensor to ensure that it is not faulty and requires regular maintenance. The fourth point is to perform regular calibration and maintenance of the flow meter. 5. Application of flow meters in the tap water industry 5. 1 Use flow meters to measure users’ water consumption. Tap water companies generally charge users corresponding fees based on the data displayed on the calculated water meters. The general flow meter management level is: purchase the flow meter, record the flow meter calibration data information in detail, install the flow meter and put it into use, and perform calibration and maintenance of the flow meter. Measuring user water consumption is generally divided into large caliber and small caliber: for small caliber, it only needs to be collected regularly by mobile phone; for large caliber, GPRS system is required for data transmission, and the data is monitored in real time through an abnormal alarm device. 5.2 Incorporate the use of flow meters and urban pipe networks into regional metering. Install flow meters according to different areas and measure the surrounding water supply. Considering the water consumption recovery rate in the area, it is necessary to conductPerform flow meter testing. Use regional flow meters to decompose the recovery rate and provide basis for water companies from point to surface. 5.3 Calculate the water volume in water plants. In general, water plants use flow meters (taking electromagnetic flow meters as an example) to measure and measure water volume, which can effectively control the production and management of the enterprise. The water inlet flow meter installed in the water plant can grasp the water volume data, which facilitates the water purification treatment and operation process control of the water plant, calculates various performance conditions of water purification treatment, and effectively controls water quality and investment costs. In addition, when the water suction pump room is operating normally, we generally use the inlet flow meter to detect whether there is abnormal flow, which can effectively detect problems with the unit. Factory flow meters can generally participate in dispatching the city's pipe network together with factory water pressure to ensure normal and stable water supply pressure. 6. Conclusion Electromagnetic flowmeters play a very important role in the operation of water companies. The accuracy of electromagnetic flowmeters directly affects the normal operation of water companies and the final economic benefits of water companies. Recently, water companies have paid more attention to flow meters and continued to conduct flow meter research and development, designing a number of high-performance and multi-specification flow meters. When our water companies select flowmeters, they should choose according to their own points and needs. During the use of the flowmeter, they need to perform regular testing and correction to ensure the accuracy of the flowmeter, and perform regular maintenance on the flowmeter to extend the flowmeter. The service life of the flow meter ensures the vital interests of water companies and users.
Hangzhou Economic Development Area，Hangzhou 310018，China
