Performance analysis of a high-efficiency multi-bed active magnetic regenerator device

Masche, M. (author), Liang, Jierong (author), DallʹOlio, Stefano (author), Engelbrecht, Kurt (author), Bahl, Christian Robert Haffenden (author)

We present the performance of an active magnetic regenerator prototype with a multi-bed concept and parallel flow circuit. The prototype applies a two-pole permanent magnet (maximum magnetic flux density of 1.44 T) that rotates over 13 tapered regenerator beds mounted on a laminated iron yoke ring. Each bed is filled with about 262 g of spherical particles, distributed in layers of ten alloys of La(Fe,Mn,Si)13Hy (CALORIVAC HS) with different Curie temperatures. Other important features are the solenoid valves, the monitoring of the temperatures exiting each bed at the cold side, and a torque meter used to measure the magnetic power required to drive the cycle. The opening behavior of the solenoid valves (i.e., the blow fraction) could be adjusted to correct flow imbalances in each bed. The device provided a maximum cooling power of about 815 W at a cycle frequency of 1.2 Hz, a utilization of 0.36, and a hot reservoir temperature of 295 K while maintaining a 5.6 K-temperature span with a coefficient of performance of 6.0. In this case, the second-law efficiency was 11.6%. The maximum second-law efficiency of 20.5%, which represents one of the largest for a magnetocaloric device, was obtained at a cycle frequency of 0.5 Hz, a utilization of 0.34, and a hot reservoir temperature of 295 K at a temperature span of 10.3 K. Under these conditions, the device absorbed a cooling load of 288 W with a coefficient of performance of 5.7. It was also shown that an unbalanced flow due to different hydraulic resistance through the beds can cause cold side outlet temperature variations, which reduce the system performance, demonstrating the importance of a well-functioning, balanced flow system.

• Language: English
• Keywords: magnetocaloric effect, cooling performance, active magnetic regenerators, first-order phase transition
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 12 str.
• Numbering: Vol. 199, art. 117569
• PID: 20.500.12556/RUL-134663
• UDC: 621.576
• ISSN on article: 1359-4311
• DOI: 10.1016/j.applthermaleng.2021.117569
• COBISS.SI-ID: 94213635
• Publication date in RUL: 25.01.2022

Record is a part of a journal

• Title: Applied thermal engineering
• Shortened title: Appl. therm. eng.
• Publisher: Elsevier Science
• ISSN: 1359-4311
• COBISS.SI-ID: 1861910

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.
• Licensing start date: 20.09.2021
• Applies to: Available online

Secondary language

• Language: Slovenian
• Keywords: magnetno hlajenje, magnetni regeneratorji, magnetokalorično hlajenje

Projects

• Funder: EC - European Commission
• Funding programme: H2020
• Project number: 814865
• Name: Renewables for clean energy buildings in a future power system
• Acronym: RES4BUILD

• Funder: Other - Other funder or multiple funders
• Funding programme: Innovation Fund Denmark
• Project number: 12-132673
• Acronym: ENOVHEAT