Yuan Class AIP & Kilo Submarine Thread

[AndrewS]

So probably Semi-Solid batteries, also from WeLion or Gotion is likely (?) and may have density of 500 Wh/kg (note: Taigei Class has conventional liquid Li-Ion battery with energy density around 250 Wh/kg)

I think the same applies to semi-solid state batteries not being mature enough. So if I had to guess, it's still LFP.

I am expecting 10 MWt will produce about 3 MWe, enough for operation of the sub most of the time, including charging the battery

I was assuming 25% efficiency, so 2.5MWe which is still enough for a sustained speed of 14 knots.

Do you think the nuclear reactor is SPARK-NC ? Lead-Bismuth-Cooled Small Modular Fast Reactor and The core is designed for Natural Circulation, so is quiet

Given the size, natural circulation seems reasonable. Not sure about the exact reactor type though.

I think it is a game changer and I am expecting PLAN will have many of these baby (>20)

If they go with 1 per year, that's a steady-state fleet of ~30 boats.
But I could see them building at a much higher rate.

 

[antiterror13]

I think the same applies to semi-solid state batteries not being mature enough. So if I had to guess, it's still LFP.



I was assuming 25% efficiency, so 2.5MWe which is still enough for a sustained speed of 14 knots.



Given the size, natural circulation seems reasonable. Not sure about the exact reactor type though.



If they go with 1 per year, that's a steady-state fleet of ~30 boats.
But I could see them building at a much higher rate.

My guess is, likely to go with Semi-Solid batteries from WeLion or Gotion with density of ~500 Wh/kg

My other guess is to produce 2-3 per year for the next 10 years or so from 2016

 

[taxiya]

So probably Semi-Solid batteries, also from WeLion or Gotion is likely (?) and may have density of 500 Wh/kg (note: Taigei Class has conventional liquid Li-Ion battery with energy density around 250 Wh/kg)

In IEPS, battery is never meant to be storing large amount of energe but meant to be buffer of high power density with high charging rate. A 2024 paper by Ma Weiming's stated that the navy developed a LFP battery of only 80Wh/kg but 75C, compared to widely availabe civilian high energy density LFP of 180Wh/kg. Yuan class uses Sterlin AIP that can generate electricity under water therefor constantly charge battery. Battery only serves for peak porformance. Taigei is a diesel-electric sub, battery is the only power source underwaster, of course it needs much larger battery pack (high energy density). They are orange and apple.

Even in civilian market semi-solid battery is not in real use. Some brands make a conceptual car running road test, it is far from mature. Military will wait many years before using it.

 

[AndrewS]

In IEPS, battery is never meant to be storing large amount of energe but meant to be buffer of high power density with high charging rate. A 2024 paper by Ma Weiming's stated that the navy developed a LFP battery of only 80Wh/kg but 75C, compared to widely availabe civilian high energy density LFP of 180Wh/kg. Yuan class uses Sterlin AIP that can generate electricity under water therefor constantly charge battery. Battery only serves for peak porformance. Taigei is a diesel-electric sub, battery is the only power source underwaster, of course it needs much larger battery pack (high energy density). They are orange and apple.

Even in civilian market semi-solid battery is not in real use. Some brands make a conceptual car running road test, it is far from mature. Military will wait many years before using it.

We also see existing SSKs max out at 20 knots.
That presumably indicates a hydrodynamic noise threshold, in addition to an increasingly inefficient power-speed curve.

If we assume 14 knots is the Type-041 sustained speed, then there's just a 6 knot gap to 20 knots.

 

[Tomboy]

From RADM Mike Brookes below. Three SSKNs

Nothing in his testimony states that three boats are launched, just some vague "Force Growth Projection" that says "up to" three smaller class SSNs "can" be added by 2027. Doesn't help that the rest of his data given are all inconsistent or extremely outdated compared to what we've actually seen.

You really need to stop taking these US public testimony or publications at face value because they are never going to put real, up to date and specific information in those.

 

[lcloo]

I have doubt on the so-called "type 041" as the definite design for a future class of SSKN. It seems to be an experimental testbed since the concept is new and there are no operational SSKN anywhere in the World ("type 041" doesn't count as operational). Even the designation type 04X is suspicious as officially there is no type 04X in PLA Navy.

The experiment might take around a decade, and if PLAN is deciding for a go ahead, the first operational SSKN might appear only around mid 2030s.

If this experimental project bear fruit, I suspect PLA would combine class type 03X and project 9X (i.e. SSK + SSN), and come out with a new type 039X class, a hybrid 3 for SSK and 9 for SSN. Such as type 0391, 0392 0393 etc. The advantage of such designation is this will confuse people with type 039B and type 039C, making identification process more tedious. Though this is 100% speculative.

 

[Tomboy]

Even the designation type 04X is suspicious as officially there is no type 04X in PLA Navy.

Though, AFAIK the designation is probably real. There is a bunch of procurement related to something called "XX1HQT" from Wuchang shipyard including optronic masts, PMM propulsion motor, electrical integration, there even is seemingly a procurement tender dated in early 2024 for a PMM of a second ship scheduled to arrive in late 2024 after the launch of the first but all procurement related ceased soon after the launch of the first in late 2024 with no follow up ever since.

HQT (HeQianTing) is literally just the pinyin initials for nuclear powered submarine while XX1 should be the designation and it can't be 031 because its taken up by the modified Golf class submarine for SLBM testing.

 

[para80]

I have doubt on the so-called "type 041" as the definite design for a future class of SSKN. It seems to be an experimental testbed since the concept is new and there are no operational SSKN anywhere in the World ("type 041" doesn't count as operational). Even the designation type 04X is suspicious as officially there is no type 04X in PLA Navy.

The experiment might take around a decade, and if PLAN is deciding for a go ahead, the first operational SSKN might appear only around mid 2030s.

I'd strongly caution on this. I dont know what the veracity is on the designation, but at least US sources (and I dont mean punditry) are supremely confident the shift is real and this is not an experimental boat only. Take it with the usual grains of salt, but its worth keeping an eye on JN in this regard, too.

 

[pesoleati]

with advancement of battery technology, solid state will be available for military use ( cost is not top concern, cutting edge technology can also be led by military application ). Aslo the battery will get even better in the future. It maybe doubling its capacity every few years. SSKN , Stering AIP and small reactor may not be worth of investment for the next 30 years.

PLAN should go all in on pure battery SSE to take the lead. If it can stay underwater for 14 days without limitation on speed, with super fast charging network consist of UUV / support ship / island base withing 2nd IC and SCS, it will be the best option for PLAN to have a fleet of 100s.

SSE will be powerful, simple, fast, quiet, cheap and even expendable if the human crew size can be reduced to the minimum with humanoid robots onboard.

 

[tphuang]

with advancement of battery technology, solid state will be available for military use ( cost is not top concern, cutting edge technology can also be led by military application ). Aslo the battery will get even better in the future. It maybe doubling its capacity every few years. SSKN , Stering AIP and small reactor may not be worth of investment for the next 30 years.

PLAN should go all in on pure battery SSE to take the lead. If it can stay underwater for 14 days without limitation on speed, with super fast charging network consist of UUV / support ship / island base withing 2nd IC and SCS, it will be the best option for PLAN to have a fleet of 100s.

SSE will be powerful, simple, fast, quiet, cheap and even expendable if the human crew size can be reduced to the minimum with humanoid robots onboard.

Battery is dense enough for UUVs, but it simply isn’t sufficient for long period of submerged submarines. Crew member requires serious space for living quarters and if you want to stay underneath without ventilation, you would also need atmospheric control. All reasons that means a nuclear electric solution using stirling makes a lot of sense here.