E-mail: belinskaya_yulka@ukr.net jbelinskaja@gmail.com
Mining dewatering plant is important stationary unit, with consumption up to 30% of all electrical energy, which is consumed by electromechanical equipment of mine. Quality and safety of main mining operations depends on its error-free and economical work.
Today the service term of more than half of mining dewatering plants is expired or they work in emergency state. Thus, the problem of control and diagnosis of plants technical state, technologic forecasting and prevention of possible faultinesses and breakdowns today becomes a relevant issue.
Scientific projection aim is ensuring of constant control of pumping facility work and automation of faultinesses diagnosis process based on vibration data.
Let us consider pump kinematical scheme of dewatering plant (figure 1). Mechanism consists of electric engine rotor 3 with bearings 1,2, connection element - coupler 3, shaft of actuating mechanism - pump 7. Shaft 7 is placed on bearings.
Figure 1 - Pump kinematical scheme of dewatering plant
1,2 - electric engine bearings; 3 - asynchronous electric engine; 4 - coupler; 5,6
-bearings of pump shaft; 7 - pump shaft .
Almost all pumping facilities are equipped with sensors of temperature control. Superheat temperature is quite informative diagnostic characteristic, but the disadvantage of almost all thermo diagnostic devices is that temperature shows not the reason, but the consequence of malfunction.
Vibration signal transmits information about state of elements of working mechanism (pumping facility). Let us develop requirements to the automatic diagnostic and protection of pumping facility device.
The automatic diagnostic and protection of pumping facility device has to discharge next functions:
There is functional scheme of the automatic diagnostic and protection of pumping facility device on figure 2.
Figure 2 - Functional scheme of the automatic diagnostic and protection of pumping facility device.
ÂÀ1-ÂÀ4 -vibration sensors; À1-À4 - amplifiers VD1-VD4 -scheme of agreement and protection ; SA1 - analogous commutator; Z - block of filters;
À2 - analog-digital converter; GB - block of intrinsically safe source;
DD1 - microcontroller; HL - light indication
Vibration sensors (ÂÀ1-ÂÀ4) - piezoelectric accelerometers are installed on the bearings. Signal of piezoelectric accelerometer arises like electric charge which is proportional to the vibration acceleration.
Then signals go to the input amplifiers of electric charge (À1-À4). Amplifiers of electric charge ensure necessary signal amplification. Output voltage of amplifier is proportional to electric charge receiving by its input.
After that signal enters to the scheme of agreement and protection (VD1-VD4), which use needs to ensure intrinsically safe and possible over voltage in the trace lines.
Then signal goes to analogous commutator. Using of analogous commutator is necessary cause of the information processing from several sensors, for gradual inquiry of analogous sensors.
Gain signal goes to the block of active filters of low and high frequencies. Filters ensure suppression of high-frequency and low-frequency interferences, which negatively influence on precision of measures.
Analog-digital converter transforms analogous signals of sensors into digital state for further processing. Fourier transformation and information processing in accordance with algorithm is carried out in microcontroller. From microcontroller information is delivered to the grass, to controller's PC and to the sub block of control and diagnostics of pump. From there the emergency switching of pump is carried out. HL - light indication, that signals of normal, boundary and emergency work mode.
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