Projects:2019s1-113 High Curie Temperature Magnetic Materials

Abstract here

Introduction

The current electric power sector is trying to increase the availability, reliability and security of energy supply to the consumers. This pursuit has increased the need to integrate renewable energy (RE) into the electricity sector as a strategy to curb the problem of energy deficiency especially in isolated off-grid settlements. However, the variability in the sources of Renewable supply coupled with conditional changes in the level of energy consumption with respect to time has brought to focus the necessity for electrical energy storage systems (ESSs) [1].

Currently, in the energy sector the issue of intermittency is currently solved using battery energy storage systems (BESS). However, BESS faces some key challenges. Once the batteries get full, battery storage will lead to wastage of all other surplus renewable energy. Battery storage also faces reduced efficiency as the batteries get older due to degradation caused by the presence of high voltages [2].

As the technologies continue to grow, more and more ESSs emerged with increased efficiency are being developed such as thermal energy storage systems (TESS), pumped hydro system (PHS), compressed air energy storage (CAES), fuel cell (FC) and superconducting magnetic energy storage (SMES) [3].

1414 Degrees is a company that specializes in Thermal Energy Storage Systems(TESS). They have developed a special Phase Change Material(PCM) with a high latent heat of fusion which they use in their TESS. A brief overview of how the TESS works is the PCM is heated using electricity up to 1414°C at this temperature, the silicon transitions to a molten phase. This allowing the storage of a significant amount of energy which can be reclaimed at a desired time i.e. when there is a demand for electricity. During times of high electrical demand, the silicon transitions from liquid to solid causing a release of heat energy. This heat energy is transformed into electrical energy via turbines that can service electrical demand[**].

The PCM is heated via electrical resistive heating that generates a lot of thermal energy losses. This project will tackle the problem of TESS using electromagnetic heating system which requires a high magnetic flux density in the presence a PCM with a high Curie temperature (Tc). Tc is the temperature above which certain materials lose their permanent magnetic properties, to be replaced by induced magnetism [4].

Project Objectives

To create an electromagnetically actuated high temperature device with the following features:

1. A small heater that can achieve the highest possible temperature, preferably at least 1400 K
2. A “switch” that can directly thermostatically control a heating load, preferably to at least 1400 K​
3. A wireless thermometer

Project team members

Project students

• Gitonga Njeru
• Nikko Mugweru Kahindi

Supervisors

• Dr Andrew Allison

1414 Degrees contacts

• Jordan Parham
• Grant Mathieson

Mechanical engineering contacts

• Dr Reza Ghomashchi
• Will Robertson
• James Anderson

Background

Curie temperature

The Curie temperature is the temperature above which the spontanteous magnetization (ferromagnetism) vanishes; it separated the disordered paramagnetic phase T > T_c from the ordered ferromagnetic phase at T < T_c[1].

References

[1] [1] Yekini Suberu, M., Wazir Mustafa, M. and Bashir, N. (2014). Energy storage systems for renewable energy power sector integration and mitigation of intermittency. [online] ELSEVIER.

[2] Divya KC, Ostergaard J. Battery energy storage technology for power systems —an overview. Electr Power Syst Res 2009;79:511–20.

[3]

[4] C. Kittel, Introduction to solid state physics. New York: J. Wiley & Sons, 1971