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Successful Practice of an Optimum Scheme for District Water Supply Measurement in Urban Area
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-----Application of the SCL-73xLL Series Insertion-type Battery-powered |
Dual-transducer Ultrasonic Flowmeter and GSM Wireless Remote Transmission System |
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| The water supply to the urban area of a city has the tendency of being made by different water supply enterprises on a district by district basis. |
| The measurement of water supply in this case has the following characteristics: large pipe size, higher demand on measuring accuracy, unavailability |
| of power source on site, mounting of meters on-line requiring no shutdown of pipe flow, and difficulties to realize centralized recording of meter readings. |
| To cope with the situation, the SCL-73xLL series insertion-type battery-powered dual-transducer ultrasonic flowmeter has been successfully developed |
| by Huizhong. As evidenced by its successful field application, the patented product is regarded by the water supply sector as a special meter most |
| suitable for use in district water supply system. The development of the meter proves to be a significant breakthrough in ultrasonic flow measurement |
| technology in China. |
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The core part of the meter is comprised of a pair of insertion-type ultrasonic transducers and a digital conversion unit. The key technology of the |
| meter lies in 3 aspects: 1) It operates with an advanced micropower consumption technology and can work continuously for a period of over 6 years |
| with a single battery cell; 2) The insertion-type transducers change from a conventional design to an integral version (Patent pending) for retaining the |
| factory-calibrated measuring accuracy on site and enabling the transducer to be mounted and maintained on-line under the pressure of pipe flow; and |
| 3) The sophisticated ¡°time-difference¡± measuring circuit is used to make the meter highly sensitive to an extremely low flowrate. |
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When used for water flow measurement in district water supply pipeline network, the SCL-73xLL flowmeter offers a high applicability and a series |
| of distinctive technical features: |
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| 1.Use of battery power for eliminating the problem arising from the unavailability of external power source on site The urban water supply pipeline |
| network is mostly located below the main downtown blocks or streets, causing it very difficult to solve the problem relating to the power supply to |
| meters. Even this problem is tackled; the accuracy of the flowmeter would be affected in case of unavoidable power failure or even man-made |
| power cut-off. Whenever power failure occurs, what is recorded by the meter is only an estimated volume of water flowing through the pipeline |
| network during the period of power failure ¨C an economic loss to the water supply enterprise. After switching to the use of battery, this issue has |
| been addressed. Moreover, the meter is capable of keeping a long-term reliable operation in a continuous manner, effectively eliminating, as |
| a result, any dispute caused by lossof meter-recorded data during power failure. |
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| 2.The capability to mount the meter on-line under the pressure of pipe flow, effectively eliminating the trouble caused by shutdown of water supply. |
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| 3.Use of twin transducers to allow the site mounted meter to have a precision identical to that after factory calibration.The meter has a patented |
| structural design to enable the 2 flow transducers to be fixed in position and easy to mount on site. The 2 transducers are inserted together into pipe |
| under pressure of water flow. The factory calibrated meter accuracy will not be affected by the deviations in mounting position, angle and distance. |
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| 4.Highly sensitive to extremely low flowrate Thanks to the use of digital electronic circuit, micropower design and the powerful digital processing |
| function, the meter¡¯s ¡°time-difference¡± detection capacity is greatly enhanced even at a flowrate as low as 0.005m/s. In case of a large pipe size |
| and a small flowrate, the meter can offer a more remarkable performance. |
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| 5.Reduction of mounting space and hence cost of building meter well The conventional insertion-type transducers are generally mounted on both |
| sides of pipe, so the meter well is required to be large in mounting space. Contrarily, the new type transducers are inserted together into the top part of |
| pipe from the latter¡¯s same side. This leads to less mounting space requirement and reduction of water well construction costs. |
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| 6.Provided with various output interfaces and capable of effecting wireless data transmission via GSM. |
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| 7.The mater and GSM communication receiver have each a protection class of IP68, making it possible for the meter to maintain a long-term |
| reliable operation in meter well. Practice shows that the meter has a remarkable performance.The insertion-type dual-transducer flowmeters have now |
| been adopted for use by a number of water supply sectors including Linghai (Liaoning Province), Longhai (Fujian Province), Binzhou (Hunan Province), |
| Zhongzhi (Yantai City, Shandong Province), Xi¡¯an, Guilin and Nanning, and Jinan Iron and Steel Co. and Siping Xiasantai Reservoir. The 40 such |
| flowmeters and the GSM meter recorded data transmission system selected for use in the district water supply system ¨C a technical remolding project |
| undertaken by Changsha Water Supply Co. of Hunan Province, have passed the technical acceptance and are now in smooth operation. |
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