Design Of System Of Ultrasonic Flowmeter Used In Mine

When the ultrasonic spreads in the liquid by a certain velocity, it carries the signal which reflects the liquid’s flow velocity and can be used to calculate the flow in some simple and reliable ways. This is the basic theory for calculating ultrasonic flowmeter. There are many advantages for using ultrasonic flowmeters such as stability, non-contact measurement, accuracy, no pressure loss, easiness in fixing and energy saving. With the development of science and technology, especially electronics and sensors, Ultrasonic gas flowmeter is paid a lot of attensions by people day by day, and began moving towards to be practical and extensive.In underground mining, gas extraction monitoring system is essential to ensure full use of energy resources at the same time prevent the occurrence of gas explosion accident. Flow measurement principle, driving transducers by low voltage, signal receiving and transmitting, power consumption were researched, and the novel ultrasonic gas flowmeter based on ultra-low power singlechip EFM32 and high precision chip TDC-GP22 was proposed. The novel ultrasonic gas flowmeter was tested by flow calibrating test rig. The results indicate that the novel ultrasonic gas flowmeter can real-timely acquire gas flow, gas concentration, pressure and temperature. The flowmeter was promising to be applied by its high precision and ultra-low power consumption.Firstly based on a amount of domestic and foreign flowmeter literatures, this paper introduces research background and development of the status both at home and abroad, and analyzes various kind of ultrasonic flow detection technology. It elaborated ultrasonic flow measuring principle that adopts the time-different method in detail, and also analyzes the factors that effect measurement accuracy.Based on above principle, this paper take the EFM32 as the core chip, respectively introduces transducer selection 、 the measuring circuit based on time-different method and Function module circuit. It elaborated design idea and give relevant hardware circuit schematic.In the software design aspect, this paper designs by using modular approach, including flow measurement module, system initialization module, data acquisition module, interactive modules and remote data transmission module. Each module elaborates on ideas and shows the flow chart, as well as important protocol or procedures.Considering the requirements of the high accuracy and low power in the industrial applying, the factors that impact measurement accuracy and power consumption of ultrasonic flowmeter system is analyzed in detail. Furthermore, optimization schemes were provided to solve related issues.At last, the performance of the ultrasonic flowmeter prototype is tested. Depend on the Sonic nozzle gas flow measurement system, the calibration of flowmeter were done and some corresponding verification result were given to determine whether the prototype was Qualified.