Permanent Magnet Type Eddy Current Heater Based on Cylindrical Halbach Array for Reducing Oil's Viscosity

摘要

The eddy current, Joule heat and input electrical power of a permanent magnet type eddy current heater based on cylindrical Halbach arrays to reduce the viscosity of crude oil in oil wells were analysed and studied by means of a three-dimensional finite-element method. The results show that when Halbach arrays generate a 0.9 T sinusoidal static field and the annulus conductor is copper, the Joule heat is about 575 W/m for a relative translational motion of 0.5 m/s in $z$ direction. The thermal efficiency of the heater is about 77.6%.