LPG/C Ship Cargo Operations Part 4A - Reliquefaction Plant Discussion for Fully Refrigerated Ship.

This segment is Part 4A series of Gas Carrier Cargo Operations on board Liquefied Petroleum Gases,
Followed by:
Part 4B - Plant Discussion continuation and Cooling Down/Loading Operation Series for Cargo Operational Procedures in segment for all the mentioned type of Gas Carrier.
Disclaimer:
The lecture or topic found in this video is my personal experience and I am just sharing my knowledge. To this date, whatever is said in here is still applicable. All content on this channel is provided for entertainment purposes only.. However, it is for educational purposes and that for cross referencing and comparison, it would be advisable to read your ship's Procedure and Manual (P & A) for any vessel you are assigned to.
The content should never be used to substitute professional advice or education.. Although every effort has been made to ensure the content is accurate and up to date. Nevertheless, it remains the responsibility of the viewer to determine its accuracy and validity.
Videos in this channel are mainly educational, informative and self help guidelines for maritime students, educators alike, seafarers and maritime collages or institutions and even the maritime industry as a whole..
Other Disclaimer:
I would like to make it clear, I am not affiliated with any Training centers. neither I represent them. The same thing goes for the Simulator maker where it was patterned in this lecture. Nevertheless, It is of bona fide intention to voluntarily endorse such entities. example.... such courses maybe available in GMI or (Gigamare Inc) or Compass Inc. and to name a few. And likewise the LCHS or Liquid Cargo Handling Simulator maker is MPRI Analytics a Division of L3 Communications. I can vouch for it when it comes to performance & accuracy. You can check with this company for your Simulator needs or requirements especially Maritime Institutions and Training centers alike.
Credits:
* Bensound for music backgrounds. www.bensound.com/
#LPGreliquefaction #ReliquefactionPlant #Thermodynamics

[@jesusromualdoricon5622]

Sir, your topics helped me to review and refresh my knowledge in Gas Operation...many thanks and keep it up...

[@ShipAhoyVlogs]

tks also for subscribing. share and pass it on to others who may benefit from it. Suggest or post questions for other matters you nay wish to explore, explained and expounded. Scrutinize if their are misleading or incorrect explanations. .

[@diazmundi4841]

Thanks sir for your explanation

[@ShipAhoyVlogs]

Most welcome

[@tristancalanoga1039]

Goodmorning sir thankyou for the idea sir

[@ShipAhoyVlogs]

Most welcome

[@vivekkumar-vi1sw]

Hi Sir, your channel is quite unique and completely helping...can u please advice me,my liquid manifold hydraulic actuator operated valve is leaking in shut condition. How to correct the leak even in shut condition. What can be the cause and how to proceed

[@ShipAhoyVlogs]

Thank you Sir for such kind comments. With regards to Hydraulic valve on your manifold. Unfortunately, there is probably one and only ship decades ago I had seen hydraulic system and I was a cadet that time. The rest was pneumatic drive valves. In this respect, technically this is part of engine department maintenance and troubleshooting. However, you can check with your ships hydraulic manuals. Basically it should be the same principles to any hydraulic system like winches or even some pumps like the framo pumping system. Or any other valves not necessarily in the manifold.

[@user-ly6jr5ye4x]

Very useful video. Advise please what is most common type of r-22 compressor: screw or reciprocating. Also as per your experience what is the most common system on board of VLGC : cascade or just 2 stage with intercooling?

[@ShipAhoyVlogs]

Thanks for your comments. Nothing much changed on board VLGC, except those newly built whose ship owners opted for the "Skid Type" (typically compact, less line up literally just a push of a button). In short, Compressor & EL. Motor room are one integration. The R22 are basically phased out (Year 2020) but not required to be replaced on present ship as long as such refrigerant still has supplier or sources. Type can vary depends on its application, since in my example, its used as the cascade for the main compressors hence screw type are just the right fit coz it can produced high pressure for small amount of gases. However, in large industrial plants inland, the reciprocating type is widely used. Lastly, both cascade and the typical two stage were experienced due to the fact that I have been on board low temp cargoes such as Ethylene, while the rest are the usual LPG's and Chemical gases. Whilst in LNG the principles are the same except that in reliquefaction (if fitted) which is nowadays, the process is even simpler. Methane are basically cooled and condensed by passing it thru a liquid nitrogen. I hope to lay out in full details but I guess its better to leave the less important and let the viewer ask the missing items. Just post, scrutinize or suggest anytime. I am not done yet with LPG, LNG is next then Crude and Clean product and Chem Tankers including Bulk and Multi-Purpose. Please share and pass it on if you feel other may learn from it. Cross reference with manual and guidelines, especially with those proper authority in learning.

[@olegno8943]

Usually VLGCs are equipped with multistage compressors with inter cooling, but normally without cascade plants. Normally you’ll not see VLGCs capable for transportation of ethylene or cargoes with temperature lower than -42 deg Celsius. Regarding LNGs - they don’t use liquid nitrogen, but they use nitrogen cooled vapours (typically with multistage water cooled turbine compressors). Why so? Because nitrogen requires a lot energy for liquefaction, so LNGs (as example Quatar Gas Q-flex or Q-max) using huge heat exchangers called Cold-box for heat exchange of compressed methane and nitrogen vapours.

[@ShipAhoyVlogs]

@@olegno8943 Yap, You are right they used compressed N2. which is basically cooler than NG. Thank you for input and correction.

[@ShipAhoyVlogs]

@@olegno8943 I was talking on the reliquefication plant in general since I was discussing Gas carriers. That is why I said nothing changed much on VLGC's and I went back discussing the rest of cascade type fitted on Ethylene ships and not necessarily VLGC's. Thanks for the Input, it is good to have someone who could comment, scrutinize or suggest.

[@olegno8943]

@@ShipAhoyVlogs I have to admit that you’re doing great job making this materials. BTW, which simulator are you using for demonstration? Is it possible to get it somewhere? When I’m training juniors onboard it’s quite challenging sometimes to show them some processes without simulation.

[@marioputrapamungkas6886]

Thank you sir, for your videos. One question sir, could you explain why the liquid is not allow on the compressor?

[@ShipAhoyVlogs]

It's a already liquid and likewise your compressor is not meant for liquid compression. You will damage it. Also, you may raise an eyebrow that contrary to popular belief..... "liquid cannot be compressed". However there are system where it does in some applications depends on the liquid but not in reliquefaction plant. However, just I said "it's already a liquid" and would be bad for your Reliquefaction system to have it go along.

[@marioputrapamungkas6886]

@@ShipAhoyVlogs understood sir, thank your for your explanation..waiting for another vidoes..

[@satyajitdilip2685]

Good Day. Can you advise why butane cargoes need 2 stage reliquefaction and propane cargoes requires 3 stage reliquefaction. What is the physics or chemistry behind this ?

[@ShipAhoyVlogs]

Propane and Butane in most ships need only Two stage, whilst in some Reliquefaction they have a 3 stage with Intercooler. Whilst others have two stage or 3 stage with or without Intercooler and/or plus combination Cascade. One of the main reasons is that if the ship is also designed for other Cargo like a colder cargo such as Propylene or Ethylene then the need for 2/3 stage with intercooler plus cascade is required. e.g. a VLGC which carriers Butane, but also carries propane or Propylene hence its system is 3 stage with intercooler but doesn't used a cascade e.g. R404 or R22(Old types) refrigerant as condensing medium. In short, its all about how fast can you reliquefy from its vaporization phase in proportion to your containment size where the plant can effectively meet the desired latent heat principle of Gas transformed to liquid and v.v. The heat enthalpy produced by this transformation is basically where reliquefaction design arrangement were based upon. I am not a reliquefaction plant maker so my answer is only based on my understanding of thermodynamics. Another example is a ship small size of 2 cargo tanks only with maximum capacity of 3,000 tons semi pressurized and semi ref carries Propane but only use 2 stage. So, again its related to the size of containment.

[@ShipAhoyVlogs]

However, my other understanding is that the colder cargo you've got and the bigger the containment then the need for more faster and effective Relique faction Plant is needed. With 2/3 stages plus intercooler the more you can bring up pressure during compression, the higher temp it could yield, the higher enthalpy, you get more rejection against coolant which it turns yields more condensation returns. With this in mind if we compare the small ship with 2 tanks yet carries Propane, it's working only on smaller vaporization volumes. Hence, 2 stages can cope up with the needed work done by the compressor. This is a good question, I hope other more well inclined expert in plant engineering should bat in cause this is not normally explained in textbook. It's an open discussion and I would like to be enlightened as well.

[@satyajitdilip2685]

@@ShipAhoyVlogs thankyou very much for your reply.

[@pankajdhaka4544]

Hello sir Nicely explained but background music is disturbing bit ….

[@nasiruibrahim3407]

I need VLGC vessel for LPG 22,000 tons and 44,000 tons for hire for 1 years

[@ShipAhoyVlogs]

You mean, you need a crew? or were onboard these ships? Great for you. Tks

[@rahnlipp2912]

Chief, in the intercooler is there both, boil off gas and liquid gas?

[@ShipAhoyVlogs]

In the Intercooler, the condensate liquid is basically used to make the gas from 1st stage compressor cools down. Hence, this would make easier for the 2nd stage to compress. This would yield higher compression pressure and heat output.

[@rahnlipp2912]

@@ShipAhoyVlogs so after the first compression the gas enters the intercooler (or cargo condenser), so liquid may form and drop out and the remaining cooler gas will be compressed again before passing the cascade portion of the system?

[@ShipAhoyVlogs]

@@rahnlipp2912 The intercooler is separate but align to the condenser. cooler gas can be compressed easier than warmer gas. hence, work done by 2nd stage is optimized. Intercooler is not shown in the simulator but its is there in application.

[@rahnlipp2912]

@@ShipAhoyVlogs Chief, thank you for your help! Last question, where would you look to determine if a LPG cargo needs 2 or 3 compression, SIGTTO?

[@ShipAhoyVlogs]

@@rahnlipp2912 Based on the intended cargo, trade of the ship, and its containment

[@derrickcarcallas9691]

Hi sir! May cargo calculation program po kayo ng LPG? Nais ko sanang mag training. Magbabayad po ako sir. Maraming salamat...

[@ShipAhoyVlogs]

Meron. Sure, pero online natin gawin mentoring. PM me 09083982993. dun mo kunin sa Polaris ang Certificate pag na tapos sa one on one.

[@tristancalanoga1039]

Kung LPG carrier yung sasakyan ko sir ano yung mga training na itake ko sir Ordinary seaman po ako sir

[@ShipAhoyVlogs]

The usual Tanker courses and ATLGT. Check with your manning for list of course matrix required.

[@tristancalanoga1039]

Thankyou sir

[@tristancalanoga1039]

Yung BTLGT at ATLGT sir ano po pinagkaiba sir

[@ShipAhoyVlogs]

@@tristancalanoga1039 Basic at advanced ung isa. most cases you will use more simulator time sa ATLGT. unless nabago na syllabus nila. di ako updated masyado sa courses.

[@tristancalanoga1039]

@@ShipAhoyVlogs thankyou sir malaking tulong po ito sakin sir sa mga idea mo sir