Study On The Technology Of Open Channel Portable Ultrasonic Flow Measurement

The total amount of water resources in China is rich,but due to the spatial distribution is uneven,resulting in the differences of water resources in the geographical are large,the overall performance is that South more than north,and.West less than East.China is a large agricultural country,agricultural water accounts for 73.4% of the country's total water consumption,facing the problem of water shortage in agriculture.At the same time,the extensive and inefficient use of water resources in China has exacerbated the shortage of agricultural water resources,so the shortage of water resources has gradually begun to restrict the rapid development of China's agriculture.Agricultural water is mainly reflected in the irrigation of farmland,The imperfect amount of water system and backward irrigation methods of China,result in the low utilization of agricultural water and a great waste of water resources,so the effective use and management of water resources is imminent.Open channel water supply is the main way of irrigation water in China.Reasonable and efficient use of channel flow can improve the utilization rate of irrigation water for farmland,and lay the foundation for the implementation of " Plan to use water,and charge according to cube ".Therefore,how to achieve accurate measurement,real-time monitoring and scientific and effective management of irrigation water is the development direction of Chinese irrigation area in future,and it is also an important measure to promote the development of the automation and information of Chinese water conservancy.Based on the current situation of irrigation area in our country,it is necessary to develop a set of automatic flow measuring device which is accurate measurement,easy to carry,stable in performance,high in automation and low in price.According to the existing open channel of irrigation area,we have designed a portable automatic ultrasonic flow measurement system and flow measuring method.Specifically,it is a kind of device which automatically measures the flow rate of open channel by using ultrasonic sensor and single chip microcomputer system based on Chezy formula.The device includes an ultrasonic probe,a supporting rod,a measuring rod,a backing plate,a single-chip and a power supply device.The device uses two ultrasonic sensors installed on the top of the channel,connected to the power can be achieved automatic flow monitoring.According to the above design ideas,this paper completed the following research contents:(1)Based on the Chezy formula and the characteristics of open channel uniform flow,the overall design of the open channel portable ultrasonic flow measurement system is completed by using the existing information technology,sensor technology,computer technology and irrigation water quantity technology;(2)according to the design of the overall scheme,a set of portable ultrasonic flow measuring mechanical device has been made;(3)According to the function of the system to achieve the measurement of the open channel flow in the irrigation area and the transmission of data,the hardware circuit of the system is designed and completed,including the main control module,liquid crystal display circuit,signal acquisition circuit,power supply circuit and wireless transmission module;(4)According to the functions of different modules of the hardware circuit and the characteristics of the client and the server,the corresponding programming language and development platform are selected,and the software program of the measurement system is designed and completed;(5)The hardware debugging,software debugging and software and hardware joint debugging of the open channel portable ultrasonic flow measurement system are carried out to realize the current measurement function of the system;(6)A large number of experiments have been done in the U channel in the laboratory and the actual irrigation channel to verify the accuracy and practicability of the system.It is proved that the current measurement system has many features by lots of experiments,like high accuracy,real-time monitoring of flow and wireless transmission of data,and the device has simple structure,low power consumption,easy to carry and low installation cost,and can be widely used in automatic monitoring of channel flow in open channel of irrigation area.