Optimization design of eddy current sensor for fuel balls detection based on electromagnetic field simulation

摘要

The fuel balls counter is used to monitor the ball-passing information in the transmission pipeline of high temperature gas-cooled reactor (HTGR). It's the eye of fuel handling system and plays an important role in ensure the reactor's safe work. Regarding the high temperature and radioactive environment in fuel handling system, eddy current testing method is the best choice for fuel balls detection. Because of the magnetic shielding of the thick walled stainless steel pipe, the ball-passing signal is weak. In order to increase signal to noise ratio and anti-interference ability, the parameter optimization of the sensor is performed by electromagnetic field simulation in this paper. The optimal goal is to maximize the coil impedance changing ratio between conditions of with and without ball inside pipeline.