AIP submarines can submerge longer than diesel-electric submarines
For many navies in countries that cannot own nuclear submarines, AIP submarines that do not rely on air propulsion engines as power have become their tireless efforts In order to obtain the entire "Sterling" power system, Japan spent huge sums of money to purchase patents and technology licenses from Sweden to build its own AIP submarines based on Swedish "Sterling" technology.
Currently, the Maritime Self-Defense Force submarine force already has 16 AIP submarines, and plans to increase this to 22 soon to strengthen the defense of the southwestern islands with relatively weak military power and far away from the mainland. By then, it will become the Asia-Pacific An underwater AIP submarine combat fleet that cannot be underestimated in the sea area.
AIP submarine is a submarine that is equipped with a new AIP system while retaining the conventional diesel-electric submarine power system. The AIP system is used as the power for its underwater low-speed navigation in order to increase the conventional diesel-electric submarine power system. The purpose of the electric submarine's underwater low-speed submersion time is to reduce the risk of being caught and exposed by enemy surface ships, anti-submarine helicopters and fixed-wing anti-submarine patrol aircraft when it floats to the snorkel state and charges.
Compared with submarines using conventional diesel-electric propulsion technology, AIP submarines can lurk underwater for a longer period of time, and their concealment is better than ordinary conventional submarines, so it is not easy to expose their position during war.
Since the 1990s, conventional AIP power systems have only begun to mature, forming two major AIP technologies: the "Stirling" power system developed by Sweden and the German fuel cell system; in addition, Japan is introducing Sweden has developed lithium batteries with higher energy density based on "Sterling" technology. It can be said to be "half" a feasible technical solution to replace the lead-acid batteries on the country's original diesel-electric submarines.
Many people on the Internet exaggerate the status of AIP submarines very high. Although the performance of AIP submarines is better than that of conventional diesel-electric submarines, the performance of AIP submarines is not outstanding. It is just better than diesel-electric submarines. Performance is slightly improved.
Whether it is the Swedish "Stirling" power system, the German fuel cell system, or the Japanese lithium battery system, although it can operate underwater without relying on air and continue to provide underwater power for submarines, But they have very little power.
For example, the output power of the "Sterling" power system is only 65-85 kilowatts. After powering the sonar, electrical equipment and electronic equipment on the boat, the remaining functions can only be used by the submarine to maintain 4 Submersible speed in knots.
Of course, the continuous underwater submersible time of AIP submarines has been changed from the maximum of 4 days for conventional diesel-electric submarines, and they must float to the snorkel state for ventilation, or simply float to the semi-submersible state of water out of the shell. , the maximum underwater submersible time has been increased to 14 days, which means that ordinary AIP submarines can stay underwater for about 10 days longer than diesel-electric submarines.
But for an AIP submarine, if it submerses at a speed of 4 knots underwater for 14 consecutive days, it will probably only submerge for more than 1,300 nautical miles at sea, and it still cannot escape anti-submarine patrols such as P-3C and Yun-8. The patrol radius of the aircraft when performing anti-submarine missions.
So, the original intention of developing AIP submarines was to enable submarines to submerge for a long time and thus avoid the search of anti-submarine patrol aircraft. In fact, it has still not been well achieved.
Therefore, if considered from this perspective, AIP submarines only extend the time for diesel-electric submarines to continuously submerge underwater, and have not truly achieved the original purpose of development, which is to avoid the search of anti-submarine patrol aircraft. and attack.
Once the fuel and liquid oxygen in the AIP power system are exhausted, the submarine will have to float to the snorkel state for ventilation, or directly surface to the semi-submersible state, start the diesel engine to charge the battery, and wait Dive again after the battery is fully charged.
If the AIP submarine is still within the search range of the fixed-wing anti-submarine patrol aircraft after 2 weeks of submersion, it will be very dangerous. After all, the current airborne search radar of the fixed-wing anti-submarine patrol aircraft is not suitable for A submarine submerged in a snorkel state on the sea surface can be detected dozens of kilometers away, and can then carry out anti-submarine torpedo, aerial bomb and depth bomb attacks, which poses a great threat to AIP submarines.
In addition, AIP submarines cannot carry out sea replenishment. In a certain compartment inside the boat, there must be several cubic meters of liquid oxygen stored, which is the most dangerous substance on the submarine. It will be attacked by anti-submarine weapons during wartime. During an attack, the liquid oxygen will become an explosive package that detonates the entire boat at any time.
Therefore, for the global submarine powers, they are still pursuing nuclear attack submarines. They do not need to float to the snorkel state or semi-submersible state to breathe. At least they can continue to covertly submerge underwater. , as long as the crew’s mental and physical strength can hold on.
Nuclear attack submarines are the trump card in underwater combat. Nuclear strategic missile submarines are both a deterrent and a display in peacetime. It is impossible to launch submarine-launched nuclear intercontinental missiles at opponents, so a nuclear war is impossible. Averted.