12b       Magnetocaloric Materials Development

Magnetocaloric materials (MCMs) have great potential to lower the energy consumption and carbon footprint of technologies used in building cooling, refrigeration, and gas liquefaction (e.g. in the liquefaction of hydrogen or natural gas). MCMs exhibit reversible temperature changes upon magnetization. When subjected to a varying magnetic field these materials undergo a change to the alignment of their magnetic fields which adsorbs or releases energy. MCMs can therefore be layered and integrated with heat transfer fluids to serve cooling applications in a highly efficient manner. The active magnetic generator concept was first introduced in 1982 and significant progress has been made (a). Recent experimental results have measured an achieved 400W of cooling power at a temerpature span of 1.5K for a COP of 1.62 (b). Still, magnetocaloric cooling systems are challenged by high capital cost, difficulty in scaling to commercial sizes, and difficulties in system integration. The high capital costs of these systems is largely attributable to the large quantities of magnets required to effect sufficient changes in temperature and the cost of the MCM materials which traditionally contain a large about of Gadolinium.

 

Accordingly, research is needed on the development of novel magnetocaloric materials that optimize the following properties at the working temperatures of the intended applications:

1. Adiabatic temperature change (∆Tad) and magnetic entropy change (∆Sm) upon a given magnitude of variation in the magnetic field

2. Susceptibility to hysteresis

3. Mechanical durability during cycling

4. Resistance to corrosion

5. Cost and use of elements that are not critical or rare

 Phase I proposals on this topic are sought which include: 1) synthesis of a magnetocaloric material that optimizes the properties listed above within a temperature range relevant for hydrogen gas liquefaction, and 2) characterization of the material’s key properties (e.g. ∆Tad and ∆Sm in a given magnetic field, particle size, sphericity, thermal conductivity, efficiency, and density). Applicants should identify the state of the art and quantify the expected improvement based on their work.

Questions – Contact: Erika Sutherland, erika.sutherland@ee.doe.gov

 

Reference

1. Barclay, J.A., 1982, Use of a ferrofluid as a heat-exchange fluid in a magnetic refrigerator. J. Applied Physics, Vol. 53, 2887-2894. http://scitation.aip.org/content/aip/journal/jap/53/4/10.1063/1.331069

2. Lozano, J.A., et al, 2013, Performance analysis of a rotary active magnetic refrigerator, J. Applied Energy, Vol. 111, 669-680. http://www.sciencedirect.com/science/article/pii/S0306261913004406