Projects / Programmes
Digital microfluidics in magnetocaloric refrigeration
| Code |
Science |
Field |
Subfield |
| 2.13.00 |
Engineering sciences and technologies |
Process engineering |
|
| Code |
Science |
Field |
| T200 |
Technological sciences |
Thermal engineering, applied thermodynamics |
| Code |
Science |
Field |
| 2.03 |
Engineering and Technology |
Mechanical engineering |
magnetocaloric, digital microfluidics, magnetic refrigeration, thermal switch, electrowetting
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
34418 |
PhD Urban Tomc |
Process engineering |
Head |
2018 - 2020 |
93 |
Organisations (1)
Abstract
The aim of the project is to gain a fundamental understanding of the dynamic thermal behaviour of two different physical effects/principles thermally coupled together for their application in a compact magnetocaloric cooling device. The magnetocaloric material (MCM), with its magnetocaloric effect (MCE), will be coupled with an ElectroWetting On Dieletric (EWOD) method to form a unique principle magnetic refrigeration process. Fast manipulation and movement of small volume liquid droplets as heat transfer fluid across the magnetocaloric material (instead of continuous fluid flow) could lead to a significant reduction of MCM mass, which in turn would lead to much more compact cooling devices. Liquid droplets would operate as a sort of thermal switches, where a droplet would e.g. absorb heat from a discrete MCM location and by rapid controlled movement release it to the other discrete MCM location or to the heat sink and vice-versa.
We will use numerical modelling to determine the most efficient thermodynamic cycling of the magnetocaloric effect (MCE) and movement of the droplets. Special consideration will be given to geometrical influences of both, the magnetocaloric material and liquid droplets, on operating conditions. Furthermore, based on the thermodynamic and electrohydrodynamic modeling, we will find an optimal electrode, and dielectric geometry, as well as develop a controller circuit to actuate the droplets according to the simulations.
Based on these findings, the first experimental proof-of-the-principle of the coupled transport phenomena of magnetocaloric material with EWOD thermal switches will be designed and built. This could be a great opportunity for subsequent development of this technology that could finally lead to the realization of incredibly compact, highly efficient and environmentally friendly refrigeration technology in the future.
The project consists of five Working Packages (WP). At the first stage of the project (WP 1) all required geometrical, liquid and electrical properties will be defined using available data in the literature and our own experimental experience to build an operational EWOD platform. Knowledge gathered in this WP will be crucial for later modeling of the electrohydrodynamics of liquid droplets. At the second stage of the project (WP 2) a numerical modelling of the coupled magnetocaloric material with EWOD thermal switches will be performed. First, the electrohydrodynamic modelling of EWOD will be performed separately. The goal is to define the optimal geometry of the EWOD, e.g. the size of the droplets and the size of electrodes to achieve a fast movement of the droplets. This electrohydrodynamic model of EWOD, will then be thermally coupled with the magnetocaloric material and its magnetocaloric effect. For this purpose, the previously developed AMR numerical model, with respective magnetocaloric properties of MCMs, will be modified and applied. A performance analysis of different geometries and operating conditions (operating frequency, thermodynamic cycles, etc.) of a MC material with implemented EWOD will be performed from a cooling characteristics point of view (temperature span, cooling power, efficiency). Based on the findings obtained by electrohydrodynamic and thermodynamic modeling, an experimental proof-of-the-principle of MC material (with its MC effect) with EWOD thermal switches will be designed and built (in WP 3). This will be followed by WP 4, where an experimental analysis will be performed. Cooling characteristics of the coupled transport phenomena will be measured at various different operating conditions. Therefore, the developed numerical models will be validated as well. The fifth work package (WP 5) will be intended for dissemination and demonstration of results, mostly through scientific publications and conference contributions. On the other hand, the positive outcome of the project will present a major breakthrough in the field of magnetic refrigera
Significance for science
During the project we will gain important insights and knowledge of the newly proposed cooling principle of magnetocaloric material (and its magnetocaloric effect) coupled with electrowetting (EWOD) principle as thermal switch. If the project is successful, this will be the first experimentally proven principle of the effective implementation of thermal switches in the magnetocaloric energy conversion. Furthermore, it will open pathways and new domains not only in the field of magnetic refrigeration, but all the other caloric technologies as well, such as electrocalorics, elastocalorics and barocalorics. Moreover, a major expansion of research activities in different fields, where thermal switch mechanisms may be found, is expected. The magnetocaloric technology will be able to finally overcome one of its major obstacles, which posed a serious issue since the dawn of its research activities, which is utilization of large quantities of rare earth materials. Most magnetocaloric materials and magnetic materials (for permanent magnets) are rare earths. To build a magnetic refrigerator, which operates with some relatively high cooling power, large masses of magnetocaloric and magnetic materials are needed, due to the low operating frequency. An efficient utilization of fast thermal switching mechanism into the magnetic cooling principle will lead to a substantial increase of the efficiency at higher operating frequencies and consequentially to higher cooling powers. This in turn will lead to the exceptional scaling down of the magnetic refrigerators, ergo to the miniaturization of the magnetocaloric technology, which will lead to the major decrease in depletion of natural resources needed for this technology.
The successful outcome of the project will give an opportunity to distribute the findings among the scientific community through high-impact-factor international scientific journals and presented them at international conferences world wide. This presents a great opportunity for Slovenian science to be represented in the international scientific community with possibilities to form new international collaborations.
Significance for the country
During the project we will gain important insights and knowledge of the newly proposed cooling principle of magnetocaloric material (and its magnetocaloric effect) coupled with electrowetting (EWOD) principle as thermal switch. If the project is successful, this will be the first experimentally proven principle of the effective implementation of thermal switches in the magnetocaloric energy conversion. Furthermore, it will open pathways and new domains not only in the field of magnetic refrigeration, but all the other caloric technologies as well, such as electrocalorics, elastocalorics and barocalorics. Moreover, a major expansion of research activities in different fields, where thermal switch mechanisms may be found, is expected. The magnetocaloric technology will be able to finally overcome one of its major obstacles, which posed a serious issue since the dawn of its research activities, which is utilization of large quantities of rare earth materials. Most magnetocaloric materials and magnetic materials (for permanent magnets) are rare earths. To build a magnetic refrigerator, which operates with some relatively high cooling power, large masses of magnetocaloric and magnetic materials are needed, due to the low operating frequency. An efficient utilization of fast thermal switching mechanism into the magnetic cooling principle will lead to a substantial increase of the efficiency at higher operating frequencies and consequentially to higher cooling powers. This in turn will lead to the exceptional scaling down of the magnetic refrigerators, ergo to the miniaturization of the magnetocaloric technology, which will lead to the major decrease in depletion of natural resources needed for this technology.
The successful outcome of the project will give an opportunity to distribute the findings among the scientific community through high-impact-factor international scientific journals and presented them at international conferences world wide. This presents a great opportunity for Slovenian science to be represented in the international scientific community with possibilities to form new international collaborations.
Most important scientific results
Interim report,
final report
Most important socioeconomically and culturally relevant results
Final report
