IIR document
Development and experimental testing of thermomagnetic motors.
Thermomagnetic motors are solid-state energy harvesters able to convert low-grade heat wastes into mechanical energy. The objective of this work is to present the key design parameters for successful thermomagnetic motor prototypes with different concepts: alternative and rotary. It includes the relation between the magnetic field source and heat transfer properties related to the magnetic heat exchanger towards the increasing of the produced power and operating frequency. Results showed that the alternative apparatus was able to operate at 1.25 Hz and produce powers of ~4.26 W (78.9 W/kg or 623.2 mW/cm3), using Gd spheres with 500 µm; while the rotary motor presented maximum velocities around 350 RPM and achieved maximum torques and powers of ~1.2 Nm and ~4.7 W (39.2 W/kg or 309.4 mW/cm3), respectively, using Gd plates with 0.9 mm thick. Both systems operated at 5oC and 35-50oC as heat sink and source temperatures. Considering the state-of-the-art, these results are among the highest values reported in the literature for thermomagnetic motors.
