Performance and durability of thin film thermocouple array on a porous electrode
journal contributionposted on 2016-09-15, 15:15 authored by Erdogan Guk, Manoj Ranaweera, Vijay Venkatesan, Jung-Sik Kim
Management of solid oxide fuel cell (SOFC) thermal gradients is vital to limit thermal expansion mismatch and thermal stress. However, owing to harsh operation conditions of SOFCs and limited available space in stack configuration, the number of techniques available to obtain temperature distribution from the cell surface is limited. The authors previously developed and studied a thermocouple array pattern to detect surface temperature distribution on an SOFC in open circuit conditions. In this study, the performance in terms of mechanical durability and oxidation state of the thin film thermoelements of the thermocouple array on the porous SOFC cathode is investigated. A thin-film multi-junction thermocouple array was sputter deposited using a magnetron sputter coater. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) characterisation techniques were carried out to understand characteristics of the thin film before and after temperature (20 °C–800 °C) measurement. Temperature readings from the sensor agreed well with the closely placed commercial thermocouple during heating segments. However, a sensor failure occurred at around 350 °C during the cooling segment. The SEM and XPS tests revealed cracks on the thin film thermoelements and oxidation to the film thickness direction.
The authors appreciate financial support from Ministry of National Education of the Republic of Turkey and the EPSRC’s UK-Korea Collaborative Research Activity in Fuel Cells project on “Novel diagnostic tools and techniques for monitoring and control of SOFC stacks”, EP/M02346X/1.
- Aeronautical, Automotive, Chemical and Materials Engineering
- Aeronautical and Automotive Engineering