The high-performance FLIR SC5000 thermal imaging camera from FLIR Systems is being used by researchers at University College London (UCL) to get a reliable thermal profile of fuel cells.
Fuel cell technology is increasingly being considered as a viable option for electricity generation to meet both environmental and energy needs. Fuel cells can be used as a source of heat and electricity for buildings, and as a power source for electric motors.
Researchers, lecturers and industrial partners at UCL’s Electrochemical Innovation Lab (EIL) are developing fuel cell technology for commercialised applications. To diagnose the performance of these systems, the lab uses a wide variety of tools, including thermal imaging cameras from FLIR.
The EIL team is continuously working on electricity production from a range of electrochemical devices including hydrogen fuel cells. A fuel cell combines hydrogen and oxygen to produce electricity, heat, and water. Just like batteries, fuel cells convert the energy produced by a chemical reaction into usable electric power. To deliver the desired amount of energy, fuel cells can be combined in series and parallel circuits to yield either a higher voltage or current to be supplied depending on the desired application. Such a design is called a fuel cell stack.
James Robinson, PhD researcher at the EIL primarily focuses on high resolution thermal imaging of batteries and fuel cells. He explains that a fuel cell has a lot of electrochemistry going on; therefore the camera’s ability to see the thermal characteristics of fuel cells allows researchers to examine the mechanism of operation and failure. The electrochemical reactions inside the fuel cell generate heat, which makes a fuel cell the perfect device to be investigated using thermal imaging cameras. By understanding the temperatures observed, thermal imaging can be used to investigate the rate of reactions, the quality of cooling systems and the overall performance of a fuel cell.
The EIL uses a wide variety of techniques to investigate fuel cells, including X-ray micro tomography, electrochemical atomic force microscopy, current mapping, off-gas analysis, high-speed photography, thermal imaging and a host of bespoke electrochemical techniques. Thermal imaging can be used to identify non-uniform generation of heat inside a fuel cell, which is usually a bad sign for the performance of the device and indicates non-uniform distribution of fuel or high electrical resistances.
According to James Robinson, temperature variations between cells can provide early signs of fuel cell stack failure or degradation. He has been using the FLIR SC5000 thermal imaging camera for R&D applications for over a year now.
The research team also uses thermocouples as an additional temperature measuring tool, next to the FLIR thermal camera. James Robinson says that the thermal camera provides a much better spatial temperature mapping, which is not possible with a thermocouple since it can only measure temperature at one spot. Using a thermocouple, one may risk losing essential information especially when working on a fuel cell with non-uniform temperature distribution.
With thermal imaging, it is possible to detect defects and faults inside the fuel cell by precise temperature measurements at a wide range of points. Defects are seen as either hot or cold spots, typically areas of high or no reaction, respectively. While measurement of these areas with a thermocouple is virtually impossible, a thermal imaging camera allows this analysis to be performed quickly and easily while also giving the exact point in space of the defect.
EIL did consider alternative thermal imaging camera brands but decided on the FLIR camera based on a combination of price and performance factors as well as a good demo by the FLIR sales representative.
The camera’s high sensitivity and high frame rate, as well as the user-friendly operation are some of the advantages of the FLIR SC5000. The FLIR ResearchIR software is aimed at R&D users of thermal imaging cameras and allows for high-speed recording and advanced thermal pattern analysis. ResearchIR enables researchers to view, record and store images at high speed, post-process fast thermal events and generate time-temperature plots from live images or recorded sequences.