A Numerical Study on Static and Dynamic Characteristics of Electromagnetic Air Compressor used in Household Refrigerators

Abstract

With the development of high-strength magnetic material, moving magnet linear compressors have been gradually introduced in the fields of refrigeration and cryogenic engineering, especially in Stirling. This paper presents computational investigations on the static and dynamic characteristics of a moving magnet. Equivalent magnetic circuits and finite element approaches have been used to model the moving magnet linear motor. In this paper an electromagnetic air compressor is used, where the piston which is a permanent magnet makes a suction stroke by the use of two electro magnets which is positioned at both inner and outer dead centers, and sucks air into the cylinder which is made by non-ferromagnetic material. The variation of force verses piston displacement and the Von Mises stress verses piston displacement is reported and results obtained. Finally, the method to identify optimal points of the linear compressor has been described, which is indispensable to the design and operation of moving magnet linear compressors.

Keywords: Computational mechanics, refrigerator, Von-Mises, piston displacement