The Research And Improvement Of The High-power Ultrasonic Oil Extraction Equipment

The ultrasonic oil extracting technology is that use the continuous high powerultrasonic signal to deal with the oil reservoir, changing the pore structure of the layerand the physical properties of the fluid. By improving the permeability and flowconditions of the oil layer, it reaches the purpose of increasing the crude oilproduction and the recovery rate. The ultrasonic oil extraction equipment mainlyincludes three aspects: the generation of the high power ultrasonic signal; the longdistance transmission of the high power signal; the conversion between the electricenergy and sound energy. There are two measures to improve the ultrasonic oilextraction equipment: completing the matching work between the transmission cableand the piezoelectric transducer which can realize the long and effective transmissionof the electric energy; the real-time acquisition, display and storage of the voltage andcurrent signals in ultrasonic processing process which can contribute to realizing themonitoring function to the instrument working condition.The characteristic impedance of the transmission cable and the equivalentimpedance of the piezoelectric transducer should be consistent when we complete thematching work between the transmission cable and the piezoelectric transducer. Wecould use the4294A impedance analyzer to measure the equivalent impedance of thetransducer, while we should use another kind of effective method to measure thecharacteristic impedance of the transmission cable. In our paper, we use the4294A todesign a new method to measure the equivalent impedance of the transducer. Thesliding rheostat is connected with the end of the cable to simulate the load resistance.And the other end of the cable is the4294A which is used to measure the curve of theinput impedance or admittance changing with the frequency. By changing the size ofthe load resistance, we could obtain a group of curves. When the load resistance isdifferent with the characteristic impedance of the transmission cable, the curve of theinput impedance or admittance has multiple maxima. The transmission efficiency ofthe cable is lowest when the impedance curve has the maximum value. Meanwhile,the transmission efficiency of the cable is highest when the admittance curve has themaximum value. The maximum value of the impedance or admittance is appearedalternately. When the value of the load resistance is equal or close to the value of the characteristic impedance, the impedance or admittance curve of the cable isapproximately a straight line which is relatively few changes with the frequency. Then,at different frequencies, the difference of the transmission efficiency of the electricsignal is relative small. With the help of the reflection and transmission characteristicsof the transmission model and the electromagnetic wave, the results are analyzed anddiscussed. And in the end, the matching application example is given between thehigh power ultrasonic transducer and the transmission cable.The monitoring function to the working condition of the instrument includes twoaspects: the hardware part and the software part. The function of the hardware is toacquire the information of the high voltage signal and the large current signal. Thespecific circuit modules include: the standard signal conversion circuit; the analog todigital conversion circuit; the external interrupt circuit; the serial port communicationcircuit; the peripheral circuit of the ATmega16, and the display circuit. The softwarepart includes the upper system and the lower system. The lower completes thefunction of the hardware, and the PC completes the function of the datacommunication and the real-time data display.