A magnetically-activated thermal switch without moving parts

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Rodrigues, C (Author) Other; Dias, MM (Author) Other; Martins, L (Author) Other; Silva, DJ (Author) Other; araujo, j. p. (Author) FCUP; J.C.R.E. Oliveira (Author) FEUP; pereira, a. m. (Author) FCUP; ventura, j. (Author) FCUP

Journal

Title: Energy Conversion and Management

Vol. 197

ISSN: 0196-8904

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 21 Citations

Scopus - 20 Citations

Other information

Authenticus ID: P-00R-44K

DOI: 10.1016/j.enconman.2019.111881

Abstract (EN): With the ever increasing power dissipation in electrical devices, new thermal management solutions are in high demand to maintain an optimal operating temperature and efficient performance. In particular, recently developed magnetically-activated thermal switches (MATSs) provide an alternative to existing devices, using the magnetic and thermal properties of superparamagnetic nanofluids to dissipate heat in a controlled manner. However, the presence of moving parts is a major drawback in these systems that must still be addressed. Herein, we present a compact and automatized MATS composed by an encapsulated superparamagnetic nanofluid and an electromagnet allowing to activate the MATS without any moving part. We investigate the effect of different temperature gradients (10, 26 and 40 degrees C) and powers applied to the coil (6.5, 15, 25 and 39 W) on the performance of this novel MATS. The results show that the highest (44.4%) and fastest (0.6 degrees C/s) temperature variation occur for the highest studied temperature gradient. On the other hand, with increasing power, there is also an increase in the efficiency of the heat exchange process between the two surfaces. These results remove one of the main barriers preventing the actual application of magnetic thermal switches and opens new venues for the design of efficient thermal management devices.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6