A System Of Measuring Multi-interface In Crude Oil Tank

With the exploitation of crude oil, most of the oil field in our country has gone into the middle and late of exploitation. Because of the high water content, the crude oil exploitated from the oil field must be separated from the water in oil tank, and processed to be low water content oil. Therefore, the real-time and accurate detection of oil-water interface in oil tank is the key to successful separate oil from water, and is also the mainly basis of managing and computering the oil volumn. This technology is very important in automatation technology.After the careful study of present methods on crude oil multi-interface detection at home and aboard, according to the character of dielectric constant varied suddently between the interfaces in oil tank, a design method of multi-interface detection system by moving capacitive sensor was proposed based on the theory of that different matter has different dielectric constant. The whole system has been finished designing, making and debugging on-line by module method.The whole instrument is made up of hardware parts and software parts. The multi-interface measurement method was demonstrated in this paper. A method of multi-interface detection in oil tank by moving capacitive sensor was proposed, and the measurement theory and system working process was introduced in detail. The capacitive sensor was detaily designed. The measurement theory of capacitive sensor was expatiated and the structure, shape and size of capacitive sensor were determined. The capacitor detection circuit was designed. In addition, the position detection system was expatiated importantly. With the development of miniature instruments, the technology of single chip system design becomes the advanced technology in our country. In this paper, a position detection single chip system by using Zylogic ZE502 in which CPU and FPGA was integrated was designed. The fourfold-frequency and direction recognition circuit, counter circuit, keyboard and display circuit, single chip system hardware-software circuit and application programme was introduced in detail. The system can real-time display the measurement data of multi-interface position, and it has many functions, such ascouter direction set, preset, diameter / radius transform, inches / centimeters transform, absolute / relative transform.. The whole system was debugged in Lab, and measurement data were gotten and analyzed. The experiment proved the design is feasible and reasonable. This system can real-time and accurate detect the multi-interfaces in oil tank.