Research On Weir Trough Open Channel Flow Measurement Instrument Used In Coal Mine

With the increase in the amount of coal mining and mining horizons increasingly deep,the probability of mine water inrush increases. Underground water harm threat has becomeone of the main factors for coal mine safety production. As the routine tasks, undergroundopen channel flow monitoring provides coal mine with important basic information andhistorical reference used to analysis the underground water harm. But the traditional weir andslotted flowmeter could cause serious deviation between measured value and the actual valuein the case of sludge deposit in the bottom of underground open channel. So, designinghigh-precision and more real-time underground open channel flowmeter is of greatsignificance to measure the underground open channel flow accurately and timely.This paper has raised an innovative flowmeter that combine ultrasonic rangingtechnology and traditional weir trough measurement methods based on the research of variousmeasurement methods used by traditional weir trough open channel flow measuringinstrument as well as ultrasonic distance measurement technology. This flowmeter wasspecifically designed for underground coal mine use. The MSP430F5438was selected to bethe microcontroller of this flowmeter. In order to calculate the actual flow value, we shouldfirstly measure the distance between the water surface of open channel and fixed point abovethe open channel as well as the water surface and sludge surface. They were measured byprecise timing chip TDC_GP2and two ultrasonic sensors which can transmit and receive bythemselves. Secondly, the thickness of actual sludge layer can be deduced by the two distancementioned above. In the end, the actual flow value could be worked out by traditional weirtrough measurement methods on the basis of the thickness of the sludge was removed. Thisnew measuring instrument also includes temperature compensation, LCD, RS485communication, and other important module. This system was programmed in C languageand it also has the function of regular data collection and low-power sleep.The laboratory simulation environment test show that both the software and hardware ofthis mine weir trough open channel flowmeter is able to reach the preset accuracy andreal-time requirements. It is also in line with mine safety standards. This mine weir troughopen channel flowmeter was proved to have better results in coal mine flow measuring andwater damage warning effect.