Chinese shipbuilder reveals breakthrough technology

[S10]

Oh so its like buying a used car and calling a new car........ its new to me

Chinese logic at its finest!

So where is China "buying" this new technology? That is quite possible the most moronic statement I've seen all week.

China developed the technology on its own, without foreign input. Naturally, it is a national breakthrough. I don't know why you are attempting to belittle the accomplishment, since your country is nowhere near us technologically.

Jealous much?

 

[帅的一匹]

When the production of 054B gonna start? i can't wait to see it.

 

[xunzi]

China does not need to overwhelm the USA, she just needs to narrow the gap and creates parity. This is already a major breakthrough in itself for national security. Like Russia, narrow the parity, and the USA wouldn't dare attack or invade.

 

[antonius123]

Overly simplistic and grossly inadequate to answer the question, which IS a legitimate question.

Yes, nuclear reaction predate the nuclear reactor, which is the containment and sustainment of a nuclear chain reaction. Yes, the nuclear reactor predate the installment of the same into mobile vessel, the submarine, for example. But the installment of the nuclear reactor into a ship is not the technological breakthrough.

Do you know what was?

Do you understand the meaning "breakthrough for china"?

In which planet are you living? everybody knows that china is far lagged behind USA in term of technology, and now they are playing catch up. And this is one of breakthrough that enable china to be on par with USA in this kind of technology.

 

[razgriz19]

This is indeed a good development. But I've few layman's level question.
Previously - Gas turbine produce mechanical power to spin propellers - direct transfer of force more efficient
Now - Gas turbine rotate electric generators to produce electricity which is used by electric motors to spin propellers - If we factor in efficiency of different step it does not sounds like an efficient solution, unless there are other advantages.

What I see that Gas turbine is the most efficient method to propel a ship. Can you a knowledgeable member list advantages (except noise reduction) of using less efficient (from energy conversion process prospective)?

not exactly. Gas turbines do not power the props directly. There is a huge and heavy gear reduction system installed between them. Jet engines spins at about 10,000 - 15,000 RPM or even more, the props just can't handle that. They would shatter if they were to spin that fast in water.

on the other hand, the faster you spin the generator, the more electricity it will produce.
Jet engines, like i mentioned have much higher RPM. And on the plus side, the engines don't have to be big, because even the smallest turbine spins at around 10,000 RPM.

I'm no expert, but i do have some knowledge on jet engines

 

[BRASSNAUTILUS]

Oh so its like buying a used car and calling a new car........ its new to me

Chinese logic at its finest!

fine example of indian logic.
buying a used car = building a car of older specifications yourself

 

[gambit]

We are talking about losses --
1. Mechanical energy transfer from turbine to alternator/ generators
2. Energy loss (efficiency) at generators- conversion rate in range of 60~80% of energy supplied
3. Efficiency of motors (% of KW supplied converted into mechanical force, adding gears means More losses)

So over it looks like a very inefficient process of converting available mechanical force to electricity and again to mechanical force to propel ship.

So I'm not able to understand how Chinese can achieve better speed and acceleration (as per article) keeping same gas turbine as it will result in less HP compare to current method. Unless they use bigger turbine but at the end od day you'll always get more power, speed, acceleration using direct coupling method.

The issue here is the media that is being used and affected.

A turbine engine uses air to burn and if we are using the engine to affect air, as in propelling a vessel through air, aka an 'airplane', then direct connection is preferred. We have turbo: fan, jet, and prop.

On the other hand, water is much thicker and more resistant to changes than air. We would have to step down several orders via a transmission with direct mechanical connection. A turbine engine here would still uses air to burn but affects water, as in moving a vessel through it.

Not sure if it would make sense for a turbine to produce electricity to turn a ducted fan assembly to fly an aircraft.

 

[BATMAN]

How about nuclear powered vessel and a gearless electric propulsion drive? or a steam turbine as primemover of AC machine and gearless electrical propulsion drive?

I see an efficient and dynamic solution.

 

[sms]

not exactly. Gas turbines do not power the props directly. There is a huge and heavy gear reduction system installed between them. Jet engines spins at about 10,000 - 15,000 RPM or even more, the props just can't handle that. They would shatter if they were to spin that fast in water.

on the other hand, the faster you spin the generator, the more electricity it will produce.
Jet engines, like i mentioned have much higher RPM. And on the plus side, the engines don't have to be big, because even the smallest turbine spins at around 10,000 RPM.

I'm no expert, but i do have some knowledge on jet engines

That's not correct!! Amount of electricity produced depends on KVA ratting of dynamo/ generator and ability of turbine to deliver the required power.

e.g. there is no way we can produce 100KVA electricity by spinning 5KVA engine at very high RPM.

 

[razgriz19]

That's not correct!! Amount of electricity produced depends on KVA ratting of dynamo/ generator and ability of turbine to deliver the required power.

e.g. there is no way we can produce 100KVA electricity by spinning 5KVA engine at very high RPM.

i never said that's the only way, I just said that's one way of creating more electricity.
of course there are other factors that also look after the power.

like i said, i'm no expert. I just shared whatever i know about the subject.

 

[Thirdfront]

That's not correct!! Amount of electricity produced depends on KVA ratting of dynamo/ generator and ability of turbine to deliver the required power.

e.g. there is no way we can produce 100KVA electricity by spinning 5KVA engine at very high RPM.

AFAIK, main advantages are response time (electric motors respond quickly), reduction of moving parts and variable power. Variable power means, operating envelope off motors is wider than GT (if sudden change in power, GT would stall/flameout).

 

[sms]

AFAIK, main advantages are response time (electric motors respond quickly), reduction of moving parts and variable power. Variable power means, operating envelope off motors is wider than GT (if sudden change in power, GT would stall/flameout).

True!!

But as previous poster wrote .. high RPM do not mean high power out put!

 

[Thirdfront]

True!!

But as previous poster wrote .. high RPM do not mean high power out put!

Yes. Typically output raises, peaks and falls with increasing RPM. Similar to IC Engines, initial rise in RPM will increase power as losses would be increasing at slower rate than increase in power. But after a critical RPM, increase in losses will by higher than the increase in power leading to overall decrease in output.

 

[antonius123]

That's not correct!! Amount of electricity produced depends on KVA ratting of dynamo/ generator and ability of turbine to deliver the required power.

e.g. there is no way we can produce 100KVA electricity by spinning 5KVA engine at very high RPM.

To some extend it could be true.
Ramping rpm could also increase power output (kva).

 

[sms]

To some extend it could be true.
Ramping rpm could also increase power output (kva).

Correct, increase in RPM will increase output provided we have enogh power to maintain the RPM at require level while generator is loaded and motors drawing more current. So in short what you get as out put is directly proposnal to what is input.

A small grinder can run up to 15K RPM can it power a ship ..think again