Over twenty years ago, I heard a joke regarding fuel cells that still makes me chuckle: the fuel cell is a technology of the future – and it always will be. I think I laughed at the time because there were so many obstacles that appeared insurmountable that it seemed like fuel cells would never become a mainstream power source. I think I am amused now because the person who wrote the joke did not foresee the hard work and development that would go into fuel cells during the coming years would eventually make the joke invalid. Four major automotive makers (Toyota, Honda, Hyundai and Daimler) have introduced fuel cell powered vehicles in the past few years and all signs point to more car makers doing the same.
The fuel cell appears to be on track to becoming a mainstream power generation device for automotive applications. It is an attractive option because it has a relatively high efficiency and because the overall emissions from the source to the wheel can be zero when fueled by hydrogen created from a renewable resource such as wind or solar power.
Foreseeing that this power source has potential to become a significant option for the automotive industry, Gamma Technologies (GT) added the ability to model a fuel cell in GT-SUITE in 2004 and we’ve continued developing our fuel cell offering in light of the recent increase of usage by the industry.
Still, the challenges of fuel cell modeling are new to many engineers, so I want to explain some of the considerations taken in fuel cell design and demonstrate how GT-SUITE is the ideal tool for addressing these challenges.
Fuel and Air Delivery System Modeling
When simulating fuel cells, one challenge is modeling the gas and delivery systems to select the optimal size for compressors, heat exchangers, and evaporators while minimizing pressure losses and keeping the gases entering the stack at the right temperature (around 100 degrees Celsius) and humidity (near 100%).
Many modelers of fuel cells are turning to GT-SUITE to simulate and design the fuel and gas delivery systems that are needed to provide the gas exchange to and from the fuel cell stack. This choice has been strongly motivated by GT-SUITE’s position as the premier software for 1-D flow solutions in the automotive industry. As a result of this interest, GT has invested into improving the capabilities even further.
In v2018, GT included with each installation a compound template that combined the existing fuel cell template with control components, injectors and ejectors to model the transfer of hydrogen fuel from the anode (fuel side in a PEM) side of the stack to the cathode (air side in PEM) and the resulting formation of water. This development gives the modeler an opportunity to more accurately simulate the overall fuel and air system by including the effects of the reduced mass of hydrogen on the fuel side and the additional mass and different properties of the gas on the air side.
To continue on this path in v2019, a new template for the fuel cell stack was developed that not only handles the mass transfer and transformation of reactants to products, but also connects directly to an electrical circuit in a GT model, enabling one to simulate the interactions between the fuel cell and the rest of the propulsion system.