Yuan Class AIP & Kilo Submarine Thread

[AndrewS]

Just asking why do you think Soryu has 230 MWh of battery power? I think it is impossible. Even if its batteries have half the energy density of an EV battery and weigh 500 tons, the Soryu's total battery storage would be around 50 MWh. More realistically it should be around 30 MWh. As for why they ditched the AIP is they want Taigei to operate in open-ocean. Low-speed endurance AIP provides is of less use in that environment and AIP provides 0 extra high-speed endurance because of its low power. They ditched it for more lithium-ion batteries for higher high-speed underwater endurance and more diesel fuel for extra range.

There was a specification document with 300Wh/kg and 230MWh for the Australian variant of the Soryu.
That would work out as 766 tonnes in total.

I'm speculating on the battery capacity of the Soryu, but if you've got accurate figures, I'd happy to hear what it is.

 

[sndef888]

Recent news of China commissioning a small modular reactor

Any chance we see a miniature style reactor for small subs?

 

[AndrewS]

Recent news of China commissioning a small modular reactor

Any chance we see a miniature style reactor for small subs?

The small modular reactor is a land-based one designed to replace coal boilers in power plants.

It's rated at 105MW which is 175x bigger than the VAU-6 which was previously investigated as an auxiliary reactor for small submarines.

 

[BoraTas]

There was a specification document with 300Wh/kg and 230MWh for the Australian variant of the Soryu.
That would work out as 766 tonnes in total.

I'm speculating on the battery capacity of the Soryu, but if you've got accurate figures, I'd happy to hear what it is.

I don't have any spec sheets for Soryu but I have specs for the Collins and GS-Yuasa's batteries. I dug specs a little bit.

1- Collins class' surfaced displacement is 3100 tons. This is the important displacement because surfaced displacement is what determines the amount of equipment in a sub. Collins class' battery weight was 400 tons. The Soryu weights 2900 tons surfaced. It is more technological but I wouldn't expect a battery weighing more than 500 tons.

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2- Soryu's batteries were supplied by GS-Yuasa. Here are the specs for its top-of-the-line industrial li-on battery modules.

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They have around 50 Ah nominal capacity and 45 V nominal voltage. They weigh 27 kg. This would translate to 2.28 kWh capacity per 27 kg. 84 Wh/kg. This module is also marketed for military applications.
I found their specs for submersible batteries:

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We don't have weight, capacity or voltage specs but they give the energy density directly. 170 Wh/kg. I don't know how cell or module specs will transfer to battery pack specs. But in EVs, the pack usually achieves around 2/3rds of the density of the cell. I would say around 80-110 Wh/kg is a safe bet for the Soryu and Taigei.

So the minimum for the Soryu Mk2 is a 400 ton battery with 80 Wh/kg density. Translating to a 32 MWh total capacity. The best case scenario is a 500 ton battery with 110 Wh/kg density. Translating to a 55 MWh total capacity.

To add to the topic. It seems Chinese manufacturers achieve similar densities too. I would expect the 039C to have between 16 MWh- 28 MHh battery capacity and AIP if they have really adopted Lithium-ion batteries.

And I also found something interesting. It seems the Lithium-ion Soryu has a larger diesel engine room. A possible third engine which the media missed?

 

[W20]

E x a c t l y

do not confuse estimates of current Japanese Submarine numbers with future figures

Also, in this imaginative drawing, perhaps +10 years should be added to the dates

 

[AndrewS]

I don't have any spec sheets for Soryu but I have specs for the Collins and GS-Yuasa's batteries. I dug specs a little bit.

1- Collins class' surfaced displacement is 3100 tons. This is the important displacement because surfaced displacement is what determines the amount of equipment in a sub. Collins class' battery weight was 400 tons. The Soryu weights 2900 tons surfaced. It is more technological but I wouldn't expect a battery weighing more than 500 tons.

Please, Log in or Register to view URLs content!

2- Soryu's batteries were supplied by GS-Yuasa. Here are the specs for its top-of-the-line industrial li-on battery modules.

Please, Log in or Register to view URLs content!

They have around 50 Ah nominal capacity and 45 V nominal voltage. They weigh 27 kg. This would translate to 2.28 kWh capacity per 27 kg. 84 Wh/kg. This module is also marketed for military applications.
I found their specs for submersible batteries:

Please, Log in or Register to view URLs content!

We don't have weight, capacity or voltage specs but they give the energy density directly. 170 Wh/kg. I don't know how cell or module specs will transfer to battery pack specs. But in EVs, the pack usually achieves around 2/3rds of the density of the cell. I would say around 80-110 Wh/kg is a safe bet for the Soryu and Taigei.

So the minimum for the Soryu Mk2 is a 400 ton battery with 80 Wh/kg density. Translating to a 32 MWh total capacity. The best case scenario is a 500 ton battery with 110 Wh/kg density. Translating to a 55 MWh total capacity.

To add to the topic. It seems Chinese manufacturers achieve similar densities too. I would expect the 039C to have between 16 MWh- 28 MHh battery capacity and AIP if they have really adopted Lithium-ion batteries.

And I also found something interesting. It seems the Lithium-ion Soryu has a larger diesel engine room. A possible third engine which the media missed?



View attachment 80300

There's a specification sheet for a Winston Battery WB-LYP10000AHA battery pack, which markets itself as used in the Yuan.
It's listed as 31MWh with a weight of 335tonnes. That works out as 92Wh/kg, which is slightly more than the GS-Yuasa industrial batteries.

If the Soryu is somewhat heavier than the Yuan, then 350-400kg of battery in the Soryu sounds like a reasonable working assumption.

---

I'm also looking at the differences between the Mk1 and the Mk2 Soryu.

The Liquid Oxygen tanks and the Stirlings have been replaced by an "unknown" space plus a third battery compartment which looks larger than the other 2 compartments.

If the original Soryu has 400kg of battery and I assume a normal deck height of 2.4m, I get a figure of 229kg for this third compartment.
But if they start using those "unknown" spaces as a 4th battery compartment, I get another 257kg of battery

So theoretically, the Soryu could have up to 900kg of battery at a stretch. If we use your estimate of 110Wh/kg, that's almost 100MWh of battery.

But there's so many assumptions built into this model.
And there are some comments on the Taigei having additional diesel generators using up some of the free space.

 

[AndrewS]

E x a c t l y

do not confuse estimates of current Japanese Submarine numbers with future figures

Also, in this imaginative drawing, perhaps +10 years should be added to the dates

View attachment 80303

Ah yes. That is very helpful.

So we're looking at 77MWh of battery, weighing about 770tonnes in the last Soryus

Plus 2 additional battery compartments at the bottom of the boat

 

[antiterror13]

There's a specification sheet for a Winston Battery WB-LYP10000AHA battery pack, which markets itself as used in the Yuan.
It's listed as 31MWh with a weight of 335kg. That works out as 92Wh/kg, which is slightly more than the GS-Yuasa industrial batteries.

If the Soryu is somewhat heavier than the Yuan, then 350-400kg of battery in the Soryu sounds like a reasonable working assumption.

---

I'm also looking at the differences between the Mk1 and the Mk2 Soryu.

The Liquid Oxygen tanks and the Stirlings have been replaced by an "unknown" space plus a third battery compartment which looks larger than the other 2 compartments.

If the original Soryu has 400kg of battery and I assume a normal deck height of 2.4m, I get a figure of 229kg for this third compartment.
But if they start using those "unknown" spaces as a 4th battery compartment, I get another 257kg of battery

So theoretically, the Soryu could have up to 900kg of battery at a stretch. If we use your estimate of 110Wh/kg, that's almost 100MWh of battery.

But there's so many assumptions built into this model.
And there are some comments on the Taigei having additional diesel generators using up some of the free space.


View attachment 80304

"' .... listed as 31MWh with a weight of 335kg. That works out as 92Wh/kg, which is slightly more than the GS-Yuasa ...."

Change the 'Kg" to "Ton" and 335 tons is not bad considering the size of Yuan is close to 4,000 tons

Perhaps the important metric is the volume of the battery as the space in SSK is a premium and very expensive

 

[AndrewS]

"' .... listed as 31MWh with a weight of 335kg. That works out as 92Wh/kg, which is slightly more than the GS-Yuasa ...."

Change the 'Kg" to "Ton" and 335 tons is not bad considering the size of Yuan is close to 4,000 tons

Perhaps the important metric is the volume of the battery as the space in SSK is a premium and very expensive

Ah yes, that should be 335 tonnes of battery in the Yuan.

Looking at the latest Soryu cutaway, it does look like the 4 battery compartments are using roughly the same space as the previous [Battery+AIP] combination

 

[antiterror13]

Ah yes, that should be 335 tonnes of battery in the Yuan.

Looking at the latest Soryu cutaway, it does look like the 4 battery compartments are using roughly the same space as the previous [Battery+AIP] combination

I'd like Yuan to have at least 100MWh of battery, with 300Wh/Kg, it would weigh around 350 tons