Summary

Magnetic refrigerators are machines cabaple of refrigerating a given volume with the magnetocaloric effect (MCE) by the action of magnets. The material used for this purpose is the so-called magnetocaloric materials (MCM), which presents the property of changing its thermal state according to the magnetic field applied over it. The MCM is used as a refrigerant and as the matrix of the so-called active magnetic regenerator (AMR), which is put into a thermodynamic cycle, in a way it will be able to transfer heat from a cold reservoir to a hot one, by the cost of magnetic work. This course completion project aims for evaluating the thermodynamic performance of a magnetic refrigerator built at the Federal University of Santa Catarina by the research group on New Technologies at Polo. The performance of the AMR was simulated by a 1-D numerical model developed at the laboratory. Two different scenarios were simulated: (i) ideally insulated regenerator and tubing, where there are no losses to the environment, and (ii) real insulated regenerator and tubing, where losses/gains are accounted. The results were used to evaluate the thermal gain to which the regenerators were exposed and to compare numerical data with previously acquired experimental data, in order to evaluate its performance. Experiments were carried for the whole system, as well as for sectioned parts, in order to analyze the energetic requirements and expenses of the main components of the prototype. This way, torque data was acquired in each proposed configuration. By the analysis of these data, it has been calculated the thermodynamic figures of merit of coefficient of performance (COP) and of thermodynamics second law efficiency (

Material for download