Application Of Magnetic Focus Incentive Coil To Corrosion Inspection Of Buried Metal Pipeline

Transient Electromagnetic method has been widely used in the detection ofremaining thickness for buried metal pipe, which has great advantages of non-contact,non-excavation, reasonable costing, non-affect of normal run, etc. However it is still alack of accurate and fast evaluation of parallel or overlapping metal pipelinedelivering the oil, gas, water, which often resulted in security incidents andenvironmental pollution. As a result, It will lead to huge losses of the nationaleconomy. In order to solve these practical application problems, Considering ofloading magnetic signal by orientation or focused, TEM system loaded into magneticfocusing is presented by Liu Jicheng, who research a new type measure of transientelectromagnetic technique based on focusing magnetic, which realize the accuratedetection method of parallel or overlapping of buried metal piping.TEM system is composed of two parts of the transmitter coil array and theemission driver circuit. In order to make transmitter coil array have magnetic focusperformance, which can increase magnetic field intensity in the target area and reducethe interference from the non-target area. Firstly, this paper is briefly overview thebasic principles of the traditional genetic algorithm, the traditional genetic algorithmwas modified to improve the global convergence rate and the convergence speed，addition construct the focusing properties for the purpose of the fitness function. andthen the CST software used in combination with optimization algorithm, which comeswith the macro language commands to write the software program calls software,realize the CST software automatically modeling, design boundary conditions, settingup incentive source, extracting solution of simulation, the results of work, realize theautomatic solution, complete model optimization, obtain A transmitter coil array withexcellent magnetic focus performance. Compared with a single transmitter loop,Numerical Simulation Results show that87.25%magnetic energy of the transmittercoil array has been focused on a radius of0.25m target area, the magnetic fieldintensity increased by52.1%. In order to make the normal work of the transmitter coil array, the matching ofthe transient electromagnetic emission driver circuit is designed in this paper, whichhas protect of under-voltage, over-current, overheating and alarm function, etc. It candisplay the battery voltage and real-time current through coil array, and currentadjustable range is0.3to2.5A, the step is0.1A; Transmit coil array turn-off delaytime is200us, Transmit pulse frequency can be selected1Hz,4Hz,8Hz. At last, Themeasurement results show that the TEM system has a perfect performance and meetsthe engineering demands, which has great application value for remaining thicknessof parallel or overlap buried metal pipeline detection.