09V/09VI (095/096) Nuclear Submarine Thread

[Senna]

There were no formal ceremonies of acceptance into active service of the new nuclear submarines after 2021 in China, which means nothing. Although in the case of Type-094 I could believe that there are 6 of them, I am of the opinion that the number of of Type-093 submarines is much, much higher.
Submarines are not "space technology" if your country is already able to build dozens of frigates, destroyers, as well as hundreds of 5th generation aircraft.
The Russians have acquired 10 new nuclear submarines since the beginning of this decade; 5 x 955A "Borei-A", 4 x 885M "Yasen-M" and one from project 09852 "Belgorod". Two more nuclear submarines were launched last year, ie one of the project Yasen-M ("Perm") and "Khabarovsk" submarine of the project 09851. A few days ago I read the info that "Ulyanovsk" (Yasen-M) is being prepared for launch.
USA; 7 Virginia-class submarines (one is Block 3 and the rest are Block 4) commissioned and 3 more Block 4 submarines were launched.

 

[para80]

These national comparisons are a little apples and oranges. China is establishing a modern nuclear powered submarine industry, and in the process both evolves and develops new designs to satisfactory standards. The large variety in 09III/A variants may be seen as evidence in this regard. Limiting production numbers while a design (and in this case also the infrastructure) is worked out is an established PLAN practice, too.

End of the day submarines dont carry hull/sail numbers anymore, and even if they did, PLAN has a demonstrated practice of changing hull numbers on surface units. Hence the best visual evidence we have is seeing for example four Type 09IV at the same time at a location etc. The reality seems to be we see a very limited number of boats, and so far we dont have even circumstantial evidence of massed SSN operations suggesting steady roation of a high volume of boats either.

The rest for now remains fully speculative beyond foreign government reports such as the CMPR. Just my two cents.

 

[ACuriousPLAFan]

Excerpts from a tender document on the hardware and software simulation systems of the entire electric propulsion system for TWO models of nuclear-powered submarines, with the designated supplier being the 719th Research Institute.

According to the original poster on Bilibili (@星依樱未), this tender is meant for the 093B and 095 SSNs. However, I think 095 SSN and 096 SSBN are likelier.

 

[plawolf]

Not directly related to the 095/96 classes themselves, but China just casually demonstrated the commercial application of a supercritical Co2 power generator.

This video gives a nice breakdown of the benefits this brings, and while he focuses primarily on the civilian power generation implications, the advancement this could bring to nuclear submarines could be hard to overstate.

This technology is basically a new tech tree from the steam engine the the overwhelming majority of the world still uses. It’s offers significant improvements in efficiency that allows you to massively reduce the size of turbines needed for the same power output, and/or massively increased power generation capacity. But most relevant for nuclear submarines, it removes the need for many of the pumps you would need for cooling in traditional steam turbines, and we all know that the biggest single source of noise on nuclear submarines is from the pumps and other equipment linked to the stream turbines.

With much reduced need for pumps and potentially much smaller turbines, the noise level of nuclear submarines using supercritical Co2 could be a fraction of that of a submarine using traditional steam turbines.

The vastly reduced start up time from half an hour to two minutes also offer potential massive advantages and unlocks tactical options no realistically available to steam powered nuclear subs, especially when paired with the naturally increased safety of essentially removed meltdown risk. So you could theoretically power down the turbine and go fully on batteries for prolonged periods when absolute silence is needed, and be able to rapidly power back up to full operational capacity.

This breakthrough is almost certainly too late to be incorporated into the 095/96 designs, but given the advanced stage of this technology in China, I would not be surprised at all of the 097/98 next gen subs start using this.

 

[The Observer]

Not directly related to the 095/96 classes themselves, but China just casually demonstrated the commercial application of a supercritical Co2 power generator.

This video gives a nice breakdown of the benefits this brings, and while he focuses primarily on the civilian power generation implications, the advancement this could bring to nuclear submarines could be hard to overstate.

This technology is basically a new tech tree from the steam engine the the overwhelming majority of the world still uses. It’s offers significant improvements in efficiency that allows you to massively reduce the size of turbines needed for the same power output, and/or massively increased power generation capacity. But most relevant for nuclear submarines, it removes the need for many of the pumps you would need for cooling in traditional steam turbines, and we all know that the biggest single source of noise on nuclear submarines is from the pumps and other equipment linked to the stream turbines.

With much reduced need for pumps and potentially much smaller turbines, the noise level of nuclear submarines using supercritical Co2 could be a fraction of that of a submarine using traditional steam turbines.

The vastly reduced start up time from half an hour to two minutes also offer potential massive advantages and unlocks tactical options no realistically available to steam powered nuclear subs, especially when paired with the naturally increased safety of essentially removed meltdown risk. So you could theoretically power down the turbine and go fully on batteries for prolonged periods when absolute silence is needed, and be able to rapidly power back up to full operational capacity.

This breakthrough is almost certainly too late to be incorporated into the 095/96 designs, but given the advanced stage of this technology in China, I would not be surprised at all of the 097/98 next gen subs start using this.

Hmmm, so the tech difference is they can try to use closed cycle CO² turbine with external heat gen (nukes, or LOx, + Diesel, etc) to power the subs.

Essentially a Sterling-ified turbine engine, with CO² as the working fluid.

 

[plawolf]

Hmmm, so the tech difference is they can try to use closed cycle CO² turbine with external heat gen (nukes, or LOx, + Diesel, etc) to power the subs.

Essentially a Sterling-ified turbine engine, with CO² as the working fluid.

More than that, the efficiency gains/ability to miniaturise the turbine and ability to omit many of the pumps needed in a traditional steam turbine will lead to significant noise reduction potent.

The rapid start up times and essentially eliminated core meltdown risk also allows the sub to shut down the Co2 turbine and go for prolonged periods on just batteries, which will make the sub basically undetectable passively.

There is an actual possibility that the rumoured mini-nuke sub might actually be running such a reactor, as a supercritical Co2 nuclear reaction could be scaled small enough to run alongside conventional diesels and batteries.

If such reactors are already commercially operating in a Chinese steel mill, the core pioneering work would have been completed years ago, and it’s hard to see the the navy missing the potential of such a breakthrough.

In terms of operational employment, using it first in a hybrid design makes perfect sense for a test and evaluation programme before looking to design a dedicated SSN around the new tech.

 

[charles18]

Not directly related to the 095/96 classes themselves, but China just casually demonstrated the commercial application of a supercritical Co2 power generator.

This video gives a nice breakdown of the benefits this brings, and while he focuses primarily on the civilian power generation implications, the advancement this could bring to nuclear submarines could be hard to overstate.
...

Don't supercritical CO2 turbines run at 700 °C ?
It's going to take a molten salt nuclear reactor to reach such temperatures.
PWR reactors are out of the question. They only operate at maybe 330 °C
I don't expect to see a Chinese aircraft carrier or submarine powered by a molten salt reactor with supercritical CO2 turbines anytime soon. Is it possible within my lifetime....sure why not?
But I think we're getting ahead of ourselves here.

 

[plawolf]

Don't supercritical CO2 turbines run at 700 °C ?
It's going to take a molten salt nuclear reactor to reach such temperatures.
PWR reactors are out of the question. They only operate at maybe 330 °C
I don't expect to see a Chinese aircraft carrier or submarine powered by a molten salt reactor with supercritical CO2 turbines anytime soon. Is it possible within my lifetime....sure why not?
But I think we're getting ahead of ourselves here.

I am not sure where you got the 700C figure from, but as I understand it, Co2 goes into its supercritical state as low as 31C at 100bar pressure.

 

[Tomboy]

I am not sure where you got the 700C figure from, but as I understand it, Co2 goes into its supercritical state as low as 31C at 100bar pressure.

I'm pretty sure the idea is that at that temperature is where sCO2 actually have a noticeable efficiency advantage over typical steam turbines. Otherwise the only other advantage is just small size and higher power density.

Anyways, I think we are getting way ahead of ourselves. There is literally 0 indication that the new SSKs are even nuclear powered and here we are already saying it is using a exotic kind of energy conversation device.

 

[plawolf]

I'm pretty sure the idea is that at that temperature is where sCO2 actually have a noticeable efficiency advantage over typical steam turbines. Otherwise the only other advantage is just small size and higher power density.

Anyways, I think we are getting way ahead of ourselves. There is literally 0 indication that the new SSKs are even nuclear powered and here we are already saying it is using a exotic kind of energy conversation device.

Do you have a source for this assertion? Especially in the context of nuclear power. Because there is nothing that I have read anywhere on sCo2 that stipulates such a high temperature requirement.

One of the main benefits of sCo2 over steam is that potential to allow you to heat it to much higher temperatures to achieve better efficiency, but the very fact that cCo2 is a quasi-liquid means you have inherently far superior turbine driving potential energy all else being equal compared to steam, and it’s this increased density that allows for turbine miniaturisation, not the higher heating potential. That’s a totally separate benefit that can be tapped into to gain even more benefits, but it’s not a prerequisite for sCo2 turbines to operate more efficiently than steam at standard PWC nuclear reactor operating temperatures.