There is a new power system in the underwater operation to enter the past and present of the lithium powered submarine.

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 There is a new power system in the underwater operation to enter the past and present of the lithium powered submarine.


The worlds first submarine Phoenix dragon powered by lithium ion batteries

In recent days, many of our friends circles have been washed by Japans latest lithium ion polymer battery submarines. Recently, Japans 11th Canglong class Phoenix Dragon conventional power submarine launched, which is the worlds first use of lithium-ion batteries as a power submarine.

As early as 2014, the Japanese Maritime Self-Defense Force announced that the Canglong class submarine, which will be launched in 2015, will revolutionize the use of lithium-ion batteries. At that time, foreign media reported that the Japanese Canglong class submarine will cancel the original AIP system while replacing lithium-ion batteries, that is, only retain the power combination of lithium-ion batteries and diesel engines. For this revolutionary idea, the views at that time were not very uniform, and many people had doubts about this rather radical design. The launching of Phoenix dragon has turned this radical design into reality.

Lithium-ion submarines are a way to improve the electric propulsion subsystem of AIP submarines when lithium-ion polymer batteries are mature, but by no means the only advanced way, said Yi Fang, a researcher at the think tank.

Battery performance constraint gave birth to the AIP submarine.

Since the submarine came into being, it has become a naval weapon developed by every country because of its unpredictable concealment and strong assault. However, the early submarines were far from the vision of the people. It is conceived that a submarine should be able to navigate deep into the ocean for as long as the Nautilus in the science fiction 20,000 miles under the sea. But technology limited peoples imagination. Until World War II, armies used diesel-powered submarines invented by scientists in the late 19th century, using internal combustion engines for surface navigation and batteries and motors for underwater navigation. And this design still has a wide market today.

Due to the limitation of battery technology, diesel-electric submarines can only navigate underwater for 10-100 hours, and must be charged. The operation of a diesel engine is inseparable from oxygen, so it must float to the surface or use a vent pipe. As a result, its concealment is greatly reduced. For this reason, people have been looking for ways to break through this constraint, nuclear power as a power is one of the options. The first American nuclear submarine designed by the United States used the name Nautilus. But limited to all kinds of restrictions, nuclear submarines are always the patents of a few countries.

Is there any better solution to the conventional power submarines with wider application?

Lead-acid batteries have been used in conventional powered submarines for hundreds of years due to slow technological advances in batteries. Lead-acid batteries are stable and reliable, the raw materials used are easy to obtain and cheap, and the structure is simple and easy to maintain. But with the advancement of battery technology, the drawbacks of lead-acid batteries have also been amplified - their size and weight are too large, their specific energy storage is very low, and their charge time is very time-consuming, that is to say, their energy density is lower than that of lithium batteries and other later generations.

Therefore, to increase the sustainability and concealment of diesel-electric submarine underwater navigation, it is very important to improve the battery power and efficiency. But the advances in battery technology obviously do not meet military needs, so people have developed an air-independent power propulsion system, the AIP system.

Early AIP submarines, such as theStirlingAIP-powered nuclear submarine, mainly used thermal engines and lead-acid batteries as electric propulsion subsystems, although improving the underwater safety performance, but reducing the underwater speed, increasing the complexity of the system. Therefore, the closed-cycle diesel engine power system, closed-cycle steam turbine power system and fuel cell power system appeared later.

Lead-acid batteries will be replaced by new batteries.

AIP submarines reduce their battery requirements to a certain extent, but that does not mean they do not need better batteries. After all, the AIP submarine system is more complicated than the diesel electric submarines.

The Phoenix Dragon replaced the entire Stirling engines AIP power system and lead-acid batteries with lithium-ion batteries while maintaining the same specifications and speed.

The design adopted by the Phoenix Dragon has given the hottest AIP submarine a new alternative to the diesel-electric submarine in technical terms.

Lead-acid batteries have a series of problems, and there is very limited room for improvement based on their working principles, but also the need for additional engine power, taking up too much space in the submarine, so once more mature battery technology, such as lithium-ion polymer batteries, will inevitably be replaced. Yi Fang said.

Lithium batteries have long been used in weapon systems, covering a wide range of military communications equipment, underwater vehicles, unmanned reconnaissance aircraft, etc. The energy density, endurance time, volume and weight of military equipment power supply are important factors affecting combat capability. Lithium batteries have the advantages of high energy density, small volume, light weight and long cycle life, which make them the first choice for military equipment power supply.

Yi Fang pointed out, Because submarines submarine power system requirements are very high, a battery technology if not mature is not dared to use rashly, because once the power supply interruption will inevitably lead to submarine safety accidents. Therefore, conventional submarines used mature lead-acid batteries before, until lithium-ion polymer batteries and other battery technology matured, began to use new alternatives.

The emergence of lithium powered submarines belongs to success.

Due to the unique advantages of conventional powered submarines, technicians from all over the world have been constantly improving their designs, including constantly trying out new battery technologies.

In addition to lithium batteries, technicians also used silver zinc batteries. In the 1950s, the U.S. tested silver-zinc batteries on a conventional high-speed test submarine, the Blue and White Fish. It is pointed out that a 1500-ton displacement submarine using 220-ton batteries can allow a 1500-ton submarine to move at 33 knots for 1.5 hours. This is the first time that a conventional submarine can reach the sporting capacity of a nuclear submarine. But silver and zinc batteries are too expensive, and the silver ingots that make them are borrowed from the U.S. Treasury.

At present, there is a kind of fuel cell AIP submarine in the family of AIP submarines, but fuel cell submarines and lithium-ion submarines in Japan are fundamentally different. Fuel cells are primary batteries that convert the chemical energy of fuel directly into electrical energy, also known as electrochemical generators. The battery belongs to the two battery. It needs charging and discharging cycle to store electric energy for discharging.

Fuel cell is a self powered battery technology. This kind of submarine can work underwater for a long time if it has enough fuel and the waste discharge is scientific. It can be regarded as a sub-nuclear submarine. Yi Fang said, lithium ion battery is a kind of battery and needs to be recharged. That is to say, after a period of submarine, lithium-ion submarine also needs to float to the surface, by the diesel generator system for charging, until the completion of charging can continue to submerge operations.

Many people are concerned that lithium batteries have been used in submarines and many weapons, so will it be widely used in the battlefield in the future, or just a substitute for the transition phase? Will the future lithium-electric submarines become the preferred configuration for future conventional powered submarines, as electric vehicles replace fuel vehicles? In this regard, Yi Fang believes that lithium batteries used in conventional submarines is only one of the mature programs, is with the emergence of relevant countries mature technology, mainly because of its high specific capacity, high output voltage of single battery, low self-discharge rate, long service life, good safety performance and other advantages, as a branch of electric propulsion system. A choice of the system is not a substitute for the transitional stage, but an inevitable choice from water to canal. In fact, a new type of high-energy thermal battery such as nickel chloride and nickel chloride is also an alternative. At present, the future of fuel cell AIP submarine is better, which is the main direction of future research. Combining fuel cell technology with battery technology can ensure better safety of conventional AIP submarine. (Zhang Qiang) this article source: Science and Technology Daily News - China Science and technology network editor: La Hai Rong _NBJS6840

Many people are concerned that lithium batteries have been used in submarines and many weapons, so will it be widely used in the battlefield in the future, or just a substitute for the transition phase? Will the future lithium-electric submarines become the preferred configuration for future conventional powered submarines, as electric vehicles replace fuel vehicles?

In this regard, Yi Fang believes that lithium batteries used in conventional submarines is only one of the mature programs, is with the emergence of relevant countries mature technology, mainly because of its high specific capacity, high output voltage of single battery, low self-discharge rate, long service life, good safety performance and other advantages, as a branch of electric propulsion system. A choice of the system is not a substitute for the transitional stage, but an inevitable choice from water to canal. In fact, a new type of high-energy thermal battery such as nickel chloride and nickel chloride is also an alternative. At present, the future of fuel cell AIP submarine is better, which is the main direction of future research. Combining fuel cell technology with battery technology can ensure better safety of conventional AIP submarine. (Zhang Qiang)