Efficient propulsion technologyFuel cells for more capable submarines

A complex cycle for high-performance fuel cells

The purpose of thyssenkrupp’s patented fuel cell system with a humidifier is to regulate the moisture content of the reactants simply and reliably. To achieve this, the patent specifies a particular arrangement of components within the fuel cell system.

In addition to the fuel cell itself, the patented system comprises a water separator, a reactant supply and a humidifier. The fuel cell process generally leaves behind water and a small amount of oxygen as by-products. Our experts make use of these by-products by feeding them back into the process. The result is that only water remains, which is extracted and then put to effective use in the humidifier.

The fuel cell’s own waste heat is used in a complex cycle to maintain the required humidity and operating temperature while increasing its efficiency. It is a win-win solution, as no additional energy is required. The result is an exceptionally compact, robust and self-contained system.

Greater safety and longer submerged missions

In practical terms, this means that the innovative propulsion technology addresses precisely what matters in naval operations. The new fuel cell is more cost-effective, delivers higher performance and enables longer submerged missions. It is also designed for long-term reliability, ensuring that it does not fail during operation. The patented system also meets the stringent safety requirements of a submarine. In the event of a fire, for example, the crew cannot simply evacuate. Safety on board was therefore a central consideration throughout the development of the innovation.

thyssenkrupp’s patent department is one of the oldest in Germany. Every year, its experts protect around 600 new innovations through patent applications.

How fuel cells enable longer and safer submerged missions

Innovative strength – and the ambition to develop tomorrow’s technologies today – also drives the experts at TKMS. Their invention of a fuel cell system with a humidifier for use on a submarine is only the first patent in a portfolio that the company has built up over recent years, focusing on the continued development and innovation of submarine propulsion technologies.

The concept of the fuel cell is around 180 years old

Since the process was first developed in 1839, it has been continuously refined, with new inventions patented time and again - including by the teams at TKMS. The fourth generation of the fuel cell has been in series production since 2020 and, thanks to its modular design, offers significant advantages for underwater use.

Today, fuel cells are used primarily in areas where conventional combustion-based generators cannot be used, or can only be used to a limited extent. One example is supplying energy to submarines equipped with air-independent propulsion systems.

Fuel cells of this kind generally use anhydrous oxygen and hydrogen as reactant gases. Inside the fuel cell, hydrogen reacts with oxygen to generate electricity, which can then be used to power a submarine. When polymer electrolyte membrane (PEM) fuel cells are used, however, it is particularly important that the gases supplied to the fuel cell have a high level of humidity at its operating temperature. This helps maintain the stability of the membrane and ensures a long service life for the fuel cell.