Following Lithium-ion Batteries: South Korean & Chinese Subs of April 9, 2021, Anonymous on April 13, 2021 kindly provided these comments and calculations (with some editing by Pete) regarding battery propulsion for China’s Yuan-class submarine:
The advertisement for China's Winston Battery WB-LYP10000AHA Lithium-ion Batteries (LIBs) indicates the average on-board consumption of a Yuan-submarine, when not moving, is some “38kW/h” meaning that its hotel load is 38kW.
The total energy of Lead-acid Batteries (LABs) (assuming they are 400 tonnes in weight) in the Yuan-class seems to be around 11 MWh or more. The Chinese make the incredible claim the Yuan-class using LABs can stay under water for 12 days! [1, 2] Such a LABs-based submarine does not exist. A capacity of 31 MWh, 3300 nm over 33 days for Yuan (LIBs) also looks like perfect nonsense. 580nm over 6 days looks more reasonable [3].
[1] A Japanese ton is the same as a metric tonne, ie. 1,000kg. This calculation example uses data of a Japanese GS-Yuasa LAB, type MSE-3000 (weight = 212kg, capacity = 3000 Ah, voltage = 2V). As the energy of a type MSE-3000 is 6 kWh ( = 3000 Ah x 2V) , then energy of 400 tonne of MSE-3000 is 11.3 MWh ( = 400 ton/212 kg x 6 kWh). Then total hotel load per day is 0.912 MWh/day (= 38 kW x 24h). Endurance is 11.3 (MWh)/0.912(MWh/day) = 12 days.
[2] Generally, the average hotel load of diesel submarine is around 150kW. Maximum (90% discharge depth) and repeatable (30% discharge depth) endurance of a Yuan-class using LABs might be 3 days or less.
[3] On LIBs, if the hotel load and propulsion output at 4 knots are 150kW and 50kW, respectively, total output per day (= (150kW + 50kW) x 24h) is 4.8MWh/day. Then endurance and distance, at 4 knots, is 6 days (90% of discharge depth) and 580nm ( = 4knots x 24h x 6 days). And endurance when not moving (= 0 knots) is 7.8 days (=31MWh / (150kW x 24h) x 0.9).
This seems like a lot of work to get a 30-year old Rubis back in service, for another ten years assuming they did an RCOH before the fire.
ReplyDeleteReckon they should call it the Saphir-Perle now.
Still cheaper and faster than building an additional Suffen class, and perhaps they can use her for pier-side training once her reactor runs out.
https://www.navalnews.com/naval-news/2021/04/naval-group-started-transplanting-a-damaged-ssn-with-a-decomissioned-submarine/
"Generally, the average hotel load of diesel submarine is around 150kW".
ReplyDeleteWhere did you get that estimate? It might have been true 40 or more years ago, but considering how electronics have advanced in the past decades, it seems incredibly inefficient for 2021 technology. I bet the truth leans closer to the chinese estimation of 38kW, than to that 150kW figure.
Hi Shawn C [your Apr 14, 2021, 9:49:00 PM]
ReplyDeleteNoting https://www.navalnews.com/naval-news/2021/04/naval-group-started-transplanting-a-damaged-ssn-with-a-decomissioned-submarine/
Yes all this work bringing a "Saphir-Perle" Rubis SSN "back" to service shows how slow the new Barracuda/Suffren class SSN replacement program will be.
Regards
Pete
Hi Pete (Apr 16, 2021, 6:13:00 AM)
ReplyDeletehttps://repository.asu.edu/attachments/227132/content/Jeon_asu_0010N_19701.pdf, Energy Management System in Naval Submarines, Byeongdoo Jeon, Page49, “Table 3. Maximum and Minimum Electrical Loads of All Systems in the Submarine”,
“Normal submerged[kW] Min” at Propulsion Load (PL) = 0kW is correspond to hotel load (say HL*) in submarine matters.
At PL = 0kW in Table 3, Hotel Load (HL)+ Auxiliary Load (AL) = 43.5 + 123 = 166.5kW.
Then HL*=150kW in is not nonsense. Large contribution of AL in submarine energy system might be neglected in (https://gwl-power.tumblr.com/post/106634862416/winston-battery-wb-lyp10000aha-in-large).
Regards
Hi Pete and Anonymous [Apr 16,2021,6:13:00 AM]
ReplyDeleteMauricio Alvarez Ortiz, Navantia's S-80 programme manager, has previously refferd to S-80 submarine's endurance as follows;[1]
"If you can switch off non-essential power consumers and reduce hotel load to 50kW, then endurance could be extended to 20 days."
"Alternatively, a submarine on the bottom could conserve power, and therefore prolong its submerged undurance, by removing the propulsion load."
The hotel load of 38kW on Yuan-class submarine must be a case of running only the essential equipments.
By the way, I had estimated the indiscretion ratio of Soryu & Taigei class submarine on my blog, and at that time I set the hotel load to "150kW" as a precondition for the estimation.
The reason is that "150kW" was mentioned in the paper of BMT defence.[2]
[1]Scott, Richard (23 November 2007)."Spains S-80A submarine comes up to the surface".Jane's Navy International. p26-31
[2]"OPTIMISING SSKTRANSIT PERFORMANCE THROUGH HULLFORM,TRANSIT MODE AND DIESEL POWERPLANT SELECTION".
http://bmt-defence.com/media/6097911/BMTDSL-Optimising-SSK-Transit-Performance-Confpaper-Pacific-Jan12.pdf
Regards
wispywood2344
Hi Anonymous and wispywood2344
ReplyDeleteDifferent subs, different hotel loads, silicon cheaps need far less hotel load power than 1960 valves. Hotel load covers much more, of course, eg. air conditioning AC that today's submariners expect when in many cold climate UK/European subs up to the 1970s there may have been no AC.
US, Mediterranean, Southeast Asian, South Asian? Northeast Asian? Israeli subs probably want AC.
Nuclear subs do have scrubbers/filters/other methods to produce breathable air and drinkable water also requiring Hotel Load power. https://science.howstuffworks.com/transport/engines-equipment/submarine2.htm
Can conventional subs economically produce breathable air and drinkable water?
https://repository.asu.edu/attachments/227132/content/Jeon_asu_0010N_19701.pdf looks a good 2020 source - so much to read - so little time.
Regards
Pete