Minyatür bir lineer kompresörün tasarım ve analizi

Linear compressors are good alternatives for the conventional rotary compressors which usually have to deal with the conversion of rotational motion to reciprocating motion before the compression step, whereas linear compressors directly generate linear motion to be used for the compression step right away. This offers many advantages over rotary compressors. While linear compressor technology is nothing new, miniature-scale linear compressor is a recent favorite. The compactness in linear compressor design combined with the smallness in scale makes this type of compressor a very interesting candidate for many practical applications, for example in the cooling of electronic equipment or in building mini refrigerators. This research deals with the detailed analysis of a prototype miniature-scale linear compressor. Basically, a linear compressor can be said to consist of two main parts: the linear actuator part which enables the reciprocating motion to the piston directly attached to it and the cylinder-valve assembly part where the interaction with the piston causes compression. The linear actuator is moving-magnet type, which, compared to the other two types, namely moving-iron and moving-coil, provides higher thrust and efficiency and lower losses. To further enhance the compactness of the design, a tubular structure is selected. An analytical model is first presented and the formulation for the magnetic flux density and the generated thrust force is shown. Then an FEM analysis is conducted, where the axisymmetric approach is used in order to have a conformity with the tubular structure. The magnetic fluxes generated inside the actuator are again calculated and the generated thrust force is demonstrated accordingly. These results are compared with the ones coming from the analytical model. The experimental setup for the linear actuator is presented and the thrust force generated is compared with the analytical results. The cylinder-valve assembly is presented and the selection and application steps as well as the estimated valve performance analysis is shown. The according manufacturing processes for the said assembly and the selection of the seal equipment for the miniature-scale problem at hand is presented. The dynamic parameters of the entire compressor assembly are presented. This is shown for both the mechanical and electromagnetic cases. The governing system dynamics equations, which includes the thrust generated by the actuator and the stiffness and damping coming from both the mechanical equipment and the compressed gas, are provided. Motor constant and excitation frequency effects are discussed. The frequency response function is shown in order to find the optimal operating point with the best system efficiency.