Spring Based Connection of External Wires to a Thin Film Temperature Sensor Integrated Inside a Solid Oxide Fuel Cell

Abstract

Thermal management of SOFCs (solid oxide fuel cell) is important for helping to minimise high temperature-related performance losses and maximising cell/stack lifetime. Thin film sensor technology is proposed as an excellent candidate to measure the cell temperature during operation due to its negligible mass, minimal disturbance to normal operation and higher temporal and spatial resolutions. However, the effective application of such sensors in SOFC systems is a challenging endeavour and predicated on incorporating the external wire attachments to complete the electrical circuit. This is because of the high sensitivity of SOFC materials to any interference to operation, limited available space and harsh operating conditions. In this paper, a new concept of packaging external wire attachments to the thin film sensor is described to enable the integration of the sensor in the SOFC system. Temperature measurements have been monitored under OCV and operating condition with the thin film sensor directly from SOFC cathode surface via proposed spring-based wire connection, from room temperature to SOFC operating temperature. The impact of the parameters including contact resistance (Rc) between sensor pads and attached wire on monitored temperature has also been analysed with the contribution of conductive paste. High temporal and spatial resolutions have been obtained with the implemented sensor.

In-situ temperature monitoring directly from cathode surface of an operating solid oxide fuel cell

“…In contrast to previously observed temperature discrepancy between the MCTA and the commercial thermocouples where the MCTA's temperature was higher than the commercial thermocouples, this graph shows that the cell temperature remains higher than the cathode gas temperature. The slightly higher temperature of the cell during cooling can be understood concerning the thermal inertia of the cell as the authors previously described the same behaviour [8], [25]. The higher heat capacity of the cell due to its greater mass compared to air makes the cell to cool slower than the ambient air.…”

“…Thus, it is critically important to increase the nature friendly technologies with increased efficiency to minimize the negative impact of fossil fuels when they are used as energy sources [1], [2]. Solid Oxide Fuel Cell (SOFC) as an energy conversion device is considered as promising technology for electricity generation due to its high conversion efficiency (50% to 75% in combined cycles) and important environmental benefits [3], [4], [5], [6], [7], [8]. This mainly comes from the direct conversion of chemical fuels to electrical energy, fuel flexibility and high operation temperature of SOFCs.…”

“…Further, in-situ temperature sensing enables to investigate the detrimental evolutions of temperature profiles induced due to changes in the operating conditions such as current, flow rate, etc. thus, facilitating real-time health monitoring [3], [6], [11].…”

Development of a Novel Multi-Channel Thermocouple Array Sensor for In-Situ Monitoring of Ice Accretion

“…MCTCA and commercial TCs measurements were recorded with a mean frequency of 0.320 Hz using an NI 9213 data logger and a proprietary LabVIEW based data logging software developed by J.-S. Kim et al [42][43][44][45][46][47][48][49][50].…”

“…To this end, this study suggests a novel ice detection sensor by using a proprietary multi-channel thermocouple array (MCTCA) technology [42][43][44][45][46][47][48][49][50] by measuring the latent heat of fusion, which is the unique physical characteristic when liquid water turns into ice. Thermoelements can be arranged in an array or grid configuration with each node spot-welded or soldered to produce a thermocouple (TC) junction.…”