SSK Diesel/Electric Sub Thread (AIP too)

[FORBIN]

2nd Dolphin II, Lahav




In fact Dolphin main mission is deterence with LACM Popeye Turbo

Please, Log in or Register to view URLs content!

 

[Jeff Head]

2nd Dolphin II, Lahav

In fact Dolphin main mission is deterence with LACM Popeye Turbo.

Nice boat!

Very nice.

 

[FORBIN]

Some interesting things on the futur A26

 

[Jeff Head]

Although this article is about the Chinese Yuan class sub's AIP, I thought it would be interesting here because they speak of the Swedish Sterling engine they imported, replicated, and improved and then they speak of the Japanese Soryu class.

Samurai? Any comments?

Please, Log in or Register to view URLs content!

Please, Log in or Register to view URLs content!

Please, Log in or Register to view URLs content!

​

In recent years several different air-independent propulsion (AIP) submarines have entered service in China and are said to be leading the world in standards, according to Duowei News, a media outlet run by overseas Chinese.

Due to the highly classified nature of submarine technology, however, the parameters of China's AIP systems have not been fully revealed to the public, the website stated. A May 1 report in Communist Party mouthpiece People's Daily, however, mentioned that China's "new Stirling engine" was 117% more efficient than its international rivals. The first hints of the details of the engine technology have gradually emerged recently. The engine will likely be adopted by the PLA Navy's new AIP submarine.

In the April 26 edition of People's Daily, in the run-up to Labor Day, a piece entitled "The 'Prettiest Worker' Reveals Why Workers are Beautiful" included the sentence: "In the field of special propulsion systems, the Stirling engine department of the 711 research institute of the China Ship Scientific Research Center has been around for 10 years and has independently developed a completely new engine, which is 117% more efficient than similar products overseas, which puts it in the lead worldwide. It is set to be installed in China's next generation of warships."

The 711 research institute is the main research unit that develops propulsion systems for conventional submarines. One of the most advanced systems it created was the AIP system for the Type 039B Song-class diesel-electric submarine, powered with Stirling engines based on engines imported into China from Sweden during the 1980s.

According to the People's Daily report, there are several models of the Swedish 4-275 propulsion system that the country is currently exporting to overseas buyers, including a 75 kilowatt and a 110 kW model. Only the 75 kW version is being sold on the international market, however. China imported the 75 kW version from Sweden then replicated the engine and used it to power the Type 039B submarine.

As the Stirling engine is not very efficient, it is normally used for slow cruising underwater. A new electricity generating technology developed in China allows the submarine to cruise underwater and charge its battery at the same time, the website stated. So although the four Stirling engines are identical in efficiency to those used in Japan's Soryu-class diesel-electric attack submarines, the Chinese submarines are afforded more tactical flexibility. Before the liquid oxygen on board the submarine is exhausted, the submarine does not need to navigate with its snorkel extended to the surface, which puts it at the same level of performance as a small nuclear submarine.

This leaves the problem of the low efficiency of the Stirling engine. The engines of the Type 039B submarine charge quite slowly. After travelling at a speed of 20 knots for several hours underwater, it needs to slow to a speed of 2 knots for several days to recharge its battery, which makes increasing the efficiency of the engine key.

This is what the 711 research institute has been working to address. According to a 2004 report by state news agency Xinhua, the engine developed by the 711 research institute has made a breakthrough in the technology. The new engine is said to have a 20 kW and a 100 kW model, said the website. The advantage of the engine is that it can be used together with other propulsion systems such as natural gas, diesel, solar energy or other solid fuels to generate electricity. This also reduces emissions compared to other engines on the market. This meant that back in 2004, China had almost equaled the power of the Swedish 110 kW 4-275 Stirling engine.

The website then speculated that the power of China's new generation of Stirling engine has likely reached the 160 kW or 217 kW mark. If new submarines were to use four Sterling engines, as the Type 039B submarine does, then this would mean power of 640 kW to 868 kW (868-1,180 horsepower). The engine would also drive the submarine at the same time as charging the battery. The Russian Kilo-class submarine has one 150 horsepower cruise generator and two emergency-use 102 horsepower generators.

This means that China's new Stirling engine can charge its main battery at the speed of a conventionally-powered submarine in snorkel mode, while travelling at a low speed of 2-3 knots. This is a unique breakthrough. Even the lithium battery powered submarine, which is under development, is unable to compete with diesel-electric submarines in terms of energy density and it still needs to charge its battery with its snorkel extended.

 

[SamuraiBlue]

Besides the sugar coated compliments it doesn't give much details so I will take it with a lump of salt as usual to any PRC press releases.

Interesting passage within the article;

The advantage of the engine is that it can be used together with other propulsion systems such as natural gas, diesel, solar energy or other solid fuels to generate electricity.

Are they suggesting to place solar panels and/or burn coal?

 

[broadsword]

Biomass, dung and hard stools.

 

[Dizasta1]

Not to sound like a sceptic, but if AIP has been mastered by the Chinese and the new Chinese Stirling engine has improved 117% over it's rivals. Then why is that similar accomplishments have not yet been achieved when it comes to propulsion systems for combat aircraft?

I'm no critic of China, rather I admire and follow with enthusiasm on all of China's achievements. Be they in the military or civilian sector.

But I find it a bit perplexing, when I hear that China has mastered the AIP and developed far better propulsion systems for submarines. And then found wanting, when it came to aircraft engines.

An advice to the country I admire very much. Technology, no matter how advanced and superior, amounts to nothing if one doesn't apply it in the correct manner. So to, one can build the greatest of weapons, fastest of aircraft and impenetrable tanks. But if your soldiers who man those weapons, don't have the strength of character, the resilience, the hardened will power and the grit and determination to fight. Then all that technology is of no use.

Great powers rise and fall from grace. But what does not change, if mastered, is the ability to draw upon the human will to carry on, despite the limitations of mortality, frailty and gravity.

So to China, I say this: "Don't ever ignore or shun away the power of the human capacity to create, as an individual. Do not subdue individuality within your power force. Encourage it and learn to harness it. Because when you do achieve this feat, then only would your advancements in technology be truly realized and applied to propel China to the heights of being a great power"

 

[Jeff Head]

Besides the sugar coated compliments it doesn't give much details so I will take it with a lump of salt as usual to any PRC press releases.

Interesting passage within the article;

Are they suggesting to place solar panels and/or burn coal?

Yes...those comments are very revealing.

I found this article to actually not say much at all definitively. When you read through it you find that they use terms like:

According to a 2004 report by state news agency Xinhua...

and...

The website then speculated that the power of China's new generation of Stirling engine has likely reached...

And then based on that comment from the 13 year old report and on some healthy speculation (which they admit), they then say:

[quotte=Article]The engine would also drive the submarine at the same time as charging the battery. This means that China's new Stirling engine can charge its main battery at the speed of a conventionally-powered submarine in snorkel mode, while travelling at a low speed of 2-3 knots. This is a unique breakthrough[/quote]

So, in other words...the big breakthrough is based on thin air.

I believe that the Chinese are using the Sterling engine...or rather that they bought one an reversed engineered it.

The Swede's are very sharp people, and I do not believe that the initial versions of a reverse-engineered engine would be as capable as the original.

No doubt whatsoever that the Chinese have sought to improve upon it. But I simply do not find the basis for believing that they now have an AIP engine that, in their words, puts their diesel/electric submarines as "at the same level of performance as a small nuclear submarine."

Based on what I read here, I think that Duowei News is getting into the fan boy category on reporting on the AIP.

 

[antiterror13]

Besides the sugar coated compliments it doesn't give much details so I will take it with a lump of salt as usual to any PRC press releases.
Interesting passage within the article;
Are they suggesting to place solar panels and/or burn coal?

I don't think it's an official press release ... I'd believe it if it was

It's more likely just a rumour and speculation

 

[broadsword]

We have seen several misreportings by Chinese reporters who give the wrong number of digits, and pundits who are not up with the latest development in technology elsewhere or simply give the wrong analysis.