April 4, 2017

Part 3 - three LIB Arrangements - Recharging and Snorting Cycles

In Two Types of Japanese Lithium-ion Batteries Being Considered (by the Japanese Navy (JMSDF)) of  February 17, 2017, the two types were:

-  “NCA” that is Lithium nickel cobalt aluminium oxide ( LiNiCoAlO) LIBs made by GS Yuasa. For main traits of NCA scroll quarter way down at. The Japanese Navy will use NCA-type batteries. Retired Japanese submarine Admiral Kobayashi advised that for mobile operations, NCA batteries and diesel may be ideal.

and

-  “LTO” that is Lithium-titanate ( Li4Ti5O12 ) LIBs made by Toshiba. For main traits of LTO scroll a third way down at. Kobayashi believes LTO types were offered to Australia for its SEA 1000, Future Submarine proposal. An ambush submarine would operate better on fuel cells, LTO and diesel.

Figure 3 (below) illustrates the time (the horizontal axis over 24 hours) and (vertical axis as MW) electrical charge/capacity changes for various types of LIB arrangements, including :

-  (A) 672 LIB-NCAs batteries in the submarine. These have a recharge life of 500
          cycles. Charge rates (C-rate) of NCA is 1C with a one-hour charge

-  (B) rather than FC-AIP, Stirling AIP+480 NCAs, (will be considered in Part 3) and 

-  (C) 672 LTOs 7000 to 15,000 cycles. The energy density of LTO LIBs are low but they
          have outanding properties such high stability, long cycle life and high C-rate. Charge 
          rates  of LTOs are 1 to 5C, with a 0.2-hour charge.

The operational needs of the submarine and the number of recharge cycles (that is, the frequency of snorts) of the 3 different arrangements over a 24 hour period.


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A big thanks to Anonymous.

4 comments:

Anonymous said...

Hi Pete

Correction of (c) 480 ITOs -- > 672 ITOs

Energy density of ITO is low as LIB, but, it has outanding properties such high stability, long cylcle life and high C-rate.

Charge rates (C-rate) of LAB, NCA and ITO are 0.2C, 1C and 1C (maximum 5C), where 0.2C, 1C and 5C are 5- hour charge, one-hour charge and 0.2-hour charge, respectively.

When charging batteries of 1Ah (1,000mAh), service times (=snorkeling time) of LAB, NCA and ITO are 5 hours, 1 hour and 12mins, respectively. ITO shows extremely fast C-rate and provides drastic reduction of snorkeling time.

In this figure, recharge frequency of ITO is set as 1/1-day, but, 1/3-days is possible with shorter time than NCA.

Regards

Nicky K.D Chaleunphone said...

Hi pete
Check out this interesting article

Taiwan struggles to acquire 5 types of submarine tech for local program
By: Mike Yeo, April 7, 2017 (Photo Credit: Sam Yeh/AFP via Getty Images)
http://www.defensenews.com/articles/taiwan-struggles-to-acquire-5-types-of-submarine-tech-for-local-program

Anonymous said...

Fewer snorkeling cycles is going to be an imperative for submarines going forward with the advent of torpedoes that can be launched at high altitude. I would put a miniature AESA radar on top of that snorkel so I can detect hunter threats at high altitude.

The US is doing that for the P-8 with the glider kit and GPS sensor on Mk54 torpedo. Range will depend on launch altitude and the weapon glide ratio as well as the launch platform speed, but if we look at 1000lb JDAM and similar glide kit, we are talking a range of 28km.

I am surprised the US has not done this but the French has gone 1 step better than JDAM with the AASM Hammer. The AASM is similar to a JDAM but it has a solid rocket booster so that doubles the range to 60km. I guess this is just a matter of time for an AASM torpedo variant.

Since we are talking 2025-2030, we may need to think about a submarine with VLS and something like a Sea Sparrow or a Barak-8 SAM inside, not just TLAM or MdCN.
KQN



Wit

Anonymous said...

Hi Pete

Indiscretion time (IR) is time the fraction of the time that the submarine spends snorkeling and can be calcurated by following modified expression of equation [1].

IR = time for snorkeling / (time for snorking + time for operating by AIP or batteries) --- (2)

In Figures 1, 2 and 3(a), IR = 12-13% (LABs), 8-9% (AIP+LABs), 6-7% (LIBs) [2, 3].

As reduction in IR makes submarin less vulnerable, strength of submarine in low speed is LIBs>=AIP+LABs>LABs.

Total strength of submarine including high speed performance is LIBs>>AIP+LABs>LABs.

[1]http://www.sname.org/HigherLogic/System/DownloadDocumentFile.ashx?DocumentFileKey=416cea4a-f339-4f76-9c75-5ae3b3d9083d page 6, equation 1.

[2] C-rate of LIBs is assumed twice higher than that of LABs. Energy consumption per hour is 250kW. Times for snorkeling on daily base of LAB, AIP+LABs and LIBs are 2.7h, 1.8h and 1.4h, respectively. Time for snorking + time for operating=24h. As estimation is rough, deviations from these values may be expected.

(Though maximum C-rate of NCA is as high as 1-h, but, actual C-rate becomes lower thanks to limitation of output of diesel generators. In NCA-submarine, output of generator is assumed to increase by 30-50%.

Regards