Design And Optimization Of Permanent Magnetic Field For Rotary Room Temperature Magnetic Refrigerators

The permanent magnetic field, as one of the three key-technologies of magnetic refrigeration, was researched in this thesis.At first, the permanent magnetic fields were designed with the finite element softwares of Ansys and Ansoft Maxwell for rotary room magnetic refrigerator. Then, the optimization of these permanent magnetic circuits was further done to gain the better performance. Finally, the interaction between the magnetic field and the magnetic bed was explored. Some important results were obtained as follows:1. Based on the Halbach rotation theorem and a hollow cylindrical flux source, a permanent magnetic array was designed for rotary room-temperature magnetic refrigerator. The magnetic field strength in the center of magnetic array's working gap is up to 1.41T with a standard deviation 0.20. Besides it, the magnetic field strength of the permanent magnetic circuit based on the magnetic circuit theorem is up to 1.57T with a standard deviation 0.13.2. Above permanent magnetic circuit was further optimized about the magnet structure parameters and the magnetic field homogeneity. After the structure optimization, the total weight of the permanent magnetic system and the permanent magnet weight based on the Halbach theorem are decreased by 21%, and 25%respectively. And the total weight of the permanent magnetic system and thepermanent magnet weight based on the magnetic circuit theorem are decreased by32% and 36% respectively.3. After optimizing the permanent circuit and adjusting the location of magneticbeds, a higher magnetic field and better running stability are gained and the radialinteraction force between the magnetic field and the magnetic bed falls from 966N to347N.