Magneto-caloric-effect-based quasi-static cooling system

摘要

This project aims at building a quasi-static cooling system that utilizes the magneto-caloric characteristics of Gadolinium. The proposed technique presents itself as an attractive choice for smart cities and a better alternative to the vapor-compression-based cooling systems used in the industry today. With its electromagnet-based novel static design feature, the system does not use any refrigerant or moving parts (except for the needed air pump and valves), hence featuring environment friendliness, suppression of vibration, noise as well as wear-out, extended lifetime, and eventually reduced cost. A novel cycle of operation was tailored in order to accommodate the usage of an impressively compact custom-designed 0.45T electromagnet as the source of magnetic field, hence omitting the usual need of rotating machines. Computer simulations estimated the system to deliver about 2 °C of cooling from an ambient 20.4 °C to 18.68 °C; and in heating mode, about 3 degrees of heating, from 20.4 to 23.33 °C. The experimental testing resulted in errors around 40 % in cooling mode and 65 % in heating. By using more efficient composite magneto-calorific materials (e.g. LaFeSi) and a stronger magnetic field, the merits of the proposed cooling system become more apparent contributing to the quiet, sustainable, and healthy environment characterizing smart cities.