A conceptual design of a thermal switch capacitor in a magnetocaloric device : experimental characterization of properties and simulations of operating characteristics

Petelin, Nada (author), Kalin, Mitjan (author), Kitanovski, Andrej (author)

The quest for better performance from magnetocaloric devices has led to the development of thermal control devices, such as thermal switches, thermal diodes, and thermal capacitors. These devices are capable of controlling the intensity and direction of the heat flowing between the magnetocaloric material and the heat source or heat sink, and therefore have the potential to simultaneously improve the power density and energy efficiency of magnetocaloric systems. We have developed a new type of thermal control device, i.e., a silicon mechanical thermal switch capacitor (TSC). In this paper we first review recently developed thermal switches based on micro-electromechanical systems and present the operation and structure of our new TSC. Then, the results of the parametric experimental study on the thermal contact resistance, as one of the most important parameters affecting the thermal performance of the device, are presented. These experimental data were later used in a numerical model for a magnetocaloric device with a thermal switch-capacitor. The results of the study show that for a single embodiment, a maximum cooling power density of 970 W m$^{−2}$ (510 W kg$_{mcm}{}^{−1}$) could be achieved for a zero-temperature span and an operating frequency of 5 Hz. However, a larger temperature span could be achieved by cascading multiple magnetocaloric elements with TSCs. We have shown that the compact TSC can be used in caloric devices, even with small temperature variations, and can be used in a variety of practical applications requiring thermal regulation.

• Language: English
• Keywords: thermal switches, magnetocalorics, cooling, thermal conductivity, thermal diffusivity, solid thermal switch capacitors, thermal control devices, heat pumps
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 15 str.
• Numbering: Vol. 5, no. 3, art. 035007
• PID: 20.500.12556/RUL-147715
• UDC: 621.56
• ISSN on article: 2515-7655
• DOI: 10.1088/2515-7655/ace288
• COBISS.SI-ID: 157226499
• Publication date in RUL: 12.07.2023

Record is a part of a journal

• Title: JPhys energy
• Shortened title: JPhys energy
• Publisher: IOP Publishing
• ISSN: 2515-7655
• COBISS.SI-ID: 529763609

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: toplotna stikala, magnetokalorika, hlajenje, toplotna prevodnost, toplotna difuzivnost