Is the OFC suitable for outdoor use? Can you showcase fascinating fuel cell technology with live measurements at science fairs? YES, YOU CAN!
At the end of June 2024, we participated in the URBAN ZERO festival in Duisburg Ruhrort. As you can guess from the leaflet, this fair was an open-air event. Not only was the sun shining, but so was our experiment-proven OFC (Figure 1):
Figure 1: The experimental setup at the URBAN ZERO science fair in Duisburg-Ruhrort
From left to right:
- Homemade electronic current load: This battery-powered load was used for all previous OFC experiments.
- DHE-driver and voltmeter: This homemade constant current source powers the optional DHE reference electrode in the OFC’s MEA to determine the anode potential. An off-the-shelf voltmeter measures the anode potential based on the DHE reference electrode.
- The OFC equipped with the optional DHE.
- Pressure regulator: The hydrogen supply for the OFC uses the HYDROSTICK. The pressure from the original output valve supplied by HORIZON fuel cell is reduced to about 100 mbar.
- Infrared camera: A small, low-budget IR camera measures the temperature of the OFC’s open cathode, operated with a smartphone (something everyone has nowadays, avoiding extra expenses).
- Power bank and USB hub: An external power bank powers the IR camera and smartphone, allowing temperature measurement for hours if the power bank’s capacity is sufficient.
As you can see, no external infrastructure is required to explore the world of fuel cells. And a pleasant environment (Figure 2) makes research even more enjoyable, so let’s get the science party going (Figure 3).
Figure 2: The entrance to the Duisport – one of the locations of the URBAN Zero science festival
Figure 3: Burghard, one of the OFC-team members, fires up the OFC to get the science party rocking
This was also the first time the cell temperature of the OFC was constantly monitored using an IR camera. The OFC warms up significantly when drawing higher currents, heating from 23°C (ambient temperature) to nearly 38°C (Figure 4 right). But why is there a cold spot on the flow field plate before measurements (Figure 4 left)? This is due to thermal reflection of the clear blue sky on the shiny gold-plated flow field plates. A piece of insulating tape eliminated that reflection. Be cautious with your IR camera to avoid misleading results by inspecting surfaces before measurements.
The usual voltage-current performance diagrams were reproduced during the fair. However, gusty winds affected the OFC’s performance in the high current regime. While operating under a load of about 4 A, a sudden gust increased the cell voltage from about 100 mV to 300 mV. Thus, demonstrating the effect of forced convection at the open cathode to boost performance compared to natural convection was not possible.
Nonetheless, it was proven that the OFC is suitable for producing great scientific results anywhere. And remember, a pleasant environment enhances the fun of research.
Below you can see IR-thermal images of the OFC. On the left (yellow image) you see the OFC prior to the experiments with blank flowfield exposed. On the right (red image) you see the OFC after drawing higher currents for some time.
