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| China-Japan-Koreas |
| Pakistan Commissions First Hangor-Class Attack Sub from China |
| 2026-05-02 |
| The Promise of Better Submarine Air-Independent Propulsion [Breitbart] AIP systems convert chemical energy (typically from hydrogen) into electric power at relatively high efficiencies—70 percent versus 35 percent for diesel engines. Thus, the risk of radar and visual detection during “snorting” is mainly present during transit to and from the target zone. (“Snorting” is submariner jargon for the leg of transit close to the surface when the snorkel head is lifted out of the water to take in air for the diesel engine.) No wonder the balance in global conventional submarine production has shifted away from the diesel engine in favor of the AIP fuel cell. Aside from the greater efficiency, there also is the simplified management of the byproducts of the reaction: Heat and water are both easy to handle. (We are ignoring the “reformer,” which “cracks” the hydrocarbon molecules to isolate the hydrogen from the carbon and feed it to the fuel cells, because the main byproduct of this process is carbon dioxide, so the same treatment plant handles that waste and the diesel engine’s.) The AIP fuel cell can be schematized by a tank fitted with two electrodes and one catalyst, filled with an electrolyte and sealed—an energy conversion device equivalent to the nuclear boiler or an internal combustion engine. By feeding hydrogen gas to the anode and gaseous oxygen to the cathode, a chemical reaction is started, and energy is produced as per the following equation: 2H2 + O2 = 2H2O + electrical energy + heat. Unfortunately, there is a limit to the quantity of hydrogen that can be stored on board because of the extreme lightness of this gas: one cubic meter of cryogenic tank can store just 71 kilograms (kg) of liquid at minus 252 degrees Celsius (a little more than 250 pounds). That is the same energy as about 200 liters of diesel fuel, but takes up about five times the volume. Therefore, since weight is Archimedes’ problem but volume affects habitability, hydrogen is stored in metal hydrates at the cost of some 72 kg of hydrates per kg of hydrogen. In the ideal world, then, a modern 1,800-ton conventional AIP submarine could carry up to 3 metric tons of hydrogen for the cost of 216 metric tons of metal hydrates, to which must be added 48 tons of liquid oxygen—some 290 tons in total for the hydrogen and oxygen cryogenic containers. In essence, we have a maximum of 70,000 kilowatt hours (kWh) for three weeks’ patrolling, or 504 hours at 4 knots with a hotel load of less than 100 kW. |
| Posted by:Skidmark |
| #2 |
| Posted by: Frank G 2026-05-02 13:05 |
| #1 |
| Posted by: trailing wife 2026-05-02 12:44 |