one with its own underwater hydrogen factory

When electric cars still crawled, a series of manufacturers launched Develop another propulsion technology: The hydrogen fuel battery. It is something that You have experienced comings, coming and changes of plans in recent years, but although it seems that It is not the future of utilitiesIt makes sense in industrial and commercial vehicles. And another sector in which it has potential is … in the submarines.

The Spanish Navy is so sure that its Crown jewelthe S-80 class submarinesthey will be the only ones in the world that work with a system that manufactures their own hydrogen.

Class S-80. Manufacturing a submarine from scratch is not simple, and Spain knows it well. The Carthaginense Isaac Peral was the inventor of the electric submarine, a precursor of the modern submarine, but Spain did not have its own underwater models during the expansion of this transport class. Since the 60s, the country built submarines under foreign licensebut at the beginning of this century, something changed and it was decided that it was time to have its own model: the Class S-80.

After years of development, delays, flotability problems and billions of euros of extra costs that forced to prolong the useful life of obsolete submarines, the first submarine of this class, the S-81 Isaac PeralHE delivered to the Navy for its assessment in November 2023, with three others planned for the coming years.

The mess of propulsion. Although in a submarine there is no more important system than another, we can say that propulsion technology directly affects the type of missions they can undertake. And there are three great technologies right now. The cheapest is conventional: submarines diesel-electricalthat can be submerged a few days because they need to recharge fuel, being a limitation for stealth operations.

On the other hand, propulsion submarines through a nuclear reactor. It is the most expensive and also the most advanced for stealth operations. France, for example, has the Barracudawhich can be submerged up to 270 days. It is a complex technology to develop a submarine from scratch. There are also purely electric, such as those who They are adopting Japan and South Korea with batteries that offer a underwater autonomy of two or three weeks, or those that assemble AIP systems.

Aip. Called independent air propulsion systems, AIPs generate electricity to feed the engine and recharge submarine batteries. The most common systems include fuel batteries that convert hydrogen and oxygen into electricity. There are variants, such as Stirling engines that use liquid fuels in this process and closed cycle vapor turbines.

It is a system that allows submerged autonomies of 20 days or more, and this is where the S-81 Isaac Peral is special because it does not store hydrogen in its batteries: it manufactures it. As? Using Bioethanol That, by means of a reformer, it becomes hydrogen that is used in a fuel pile together with liquid oxygen to produce electricity.

Diagram of an AIP system of the submarines of India

Best Aip. They are funny acronyms that respond to Bio-Ethanol Stealth Technology and is not really new, but of interesting application in a submarine. As our partners comment Motorpasionit was in 1991 when, in the laboratory of catalytic processes of the Faculty of Engineering of the University of Buenos Aires, they developed a method for obtain hydrogen from ethanol. In a submarine, it makes all the meaning: the risk of storage hydrogen is eliminated, aboard is produced and the waste (CO₂ and water) is expelled to the ocean in the form of carbonated water that does not increase the acoustic or thermal firm of the ship.

This system, according to Manuel Corral Iranzo, under the command of the S-81 since the delivery in 2023, in statements to The debateit is “worldwide pointer” and it is something that has many advantages. Ethanol “is a matter not as dangerous as hydrogen and is easily obtained. It is a revolutionary system and no other country or any other submarine has this hydrogen production system on board,” he says.

It is not yet mounted … There is a problem: this revolutionary system, which is clearly the jewel of the Crown of the S-80 class, is not prepared. As we read in Defensein parallel to the delivery of the first submarine in November 2023, the factory tests of the Best Aip system began to pass. The submarine was delivered without this oxygen generation system, which will be installed in its first large technical stop. When? Well this update is planned by 2029-2030. At the moment, the submarine has three diesel generators of 1,100 kW each and a main electric motor of 3,500 kW.

After the S-81, the next one that will be delivered at some point in 2025, and after Another delayis the S-82 Narciso Monturiol. Nor will the Best Aip system will have, but it will be implemented in its technical stop of 2031 if there are no delays. Those who will have the factory best AIP will be the S-83 and S-84, dated by 2026 and 2028 respectively.

Images | Angeldr88, To Guy Named Nyal, Navy, Martinvl, India Ministry of Defense

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