Researchers at the University College London (UCL) are using FLIR thermal imaging cameras to support their study of fuel cell and battery technology.
Fuel cell technology is widely regarded as a very promising way to meet current and future 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 at UCL’s Electrochemical Innovation Lab (EIL), who are involved in developing fuel cell technology for commercialised applications, are using a variety of tools including thermal imaging cameras from FLIR to diagnose the performance of these systems.
At the EIL, researchers, lecturers and industrial partners are 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, and the ability to see the thermal characteristics of fuel cells allows them to examine the mechanism of operation and failure. These electrochemical reactions inside the fuel cell generate heat, which makes the fuel cell a 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 is 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, reducing the current being produced, or cell-to-cell variations.
According to James Robinson, temperature variations between cells can provide early signs of fuel cell stack failure or degradation.
At the EIL, James Robinson has been using the FLIR SC5000 thermal imaging camera for R&D applications for over a year now. While the lab also uses thermocouples as an additional temperature measuring tool, next to the FLIR thermal camera, James Robinson says that a thermal camera gives a much better spatial temperature mapping, which is not possible with a thermocouple. One could risk losing essential information when using a thermocouple especially while working with fuel cells 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.
While the lab did consider several thermal imaging camera brands, James Robinson said they were convinced about the FLIR camera based on a combination of price and performance factors, and a good demo by the FLIR sales representative.
The camera’s high sensitivity and high frame rate, which are very valuable for getting reliable temperature results, as well as its ease of use, are some of the advantages observed by the research team. The FLIR ResearchIR software is also used for thermal pattern analysis. Aimed at R&D users of thermal imaging cameras, 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.