Study of the Energy Conversion Chain in a Thermomagnetic Generator

Smail Ahmim (1) , Morgan Almanza (1) , Oleksandr Pasko (1) , Frédéric Mazaleyrat (1) , Martino Lobue (1)

1 SATIE - Systèmes et Applications des Technologies de l'Information et de l'Energie

Thermomagnetic generators designed to scavenge electrical energy from a heat flow can be designed following different conversion chains. Here we numerically study a device based on a three steps conversion, from magnetic towards kinetic, and eventually electrical energy. This chain is assured by a magnetocaloric material (MCM) as active substance moving between the heat reservoirs on an elastic beam (polypropylene: 60.6 x 26.6 x 1.2 mm 3) designed to obtain an auto-oscillating system. The cantilever kinetic energy is recovered using piezoelectric patches (PZT 5a). After optimization of the patches size, our simulations give an output energy density of 0.03 mJcm-3. To achieve a further optimization we investigate the possibility to use the piezoelectric material both as a transducer and as an actuator to have a better control of the working thermodynamic cycle. In this way we show that an energy density up to 60.46 mJcm-3 can be achieved.

Mots clés: magnetocaloric materials; thermomagnetic generator; energy harvesting

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Smail Ahmim, Morgan Almanza, Oleksandr Pasko, Frédéric Mazaleyrat, Martino Lobue. Study of the Energy Conversion Chain in a Thermomagnetic Generator. 8th International Conference on Caloric Cooling (Thermag VIII), Sep 2018, Darmstadt, Germany. pp.197-201, ⟨10.18462/iir.thermag.2018.0032⟩. ⟨hal-02389352⟩