Ship refrigeration

[MilosBog]

Hi all,
anybody has an experience in this matter? I am interested in concept and possible problems. For engines cooling

[sedgy]

hi milosbog, yes I worked on ships , most engine cooling is done using sea water< very cheap< and LOTS of it did you have any particular question? sedgy

[MilosBog]

Generally i am interested in concept, the rest is just flowing the rules. Do you have any schematic? How dd you connect the seawater to the engines? Have you used a Heat exchanger? if yes, which one, Titanium or?. For air conditioning and for ice making do you have also the seawater coked condenser? Any advice would be appreciated

[sedgy]

hi, its 40 years ago since I was at sea , < the good old days< on water cooled units < the condencing units are allways bigger than air cooled, and ships can be in the red sea or the north atlantic the sea temp can be vastly different.
I would have thought you would be buying plant for a specific unit ? or where you thinking of getting it made to your own spec? keep us up to speed, there wioll be more ex .marine guys out there , all the best for now , sedgy,

[MilosBog]

Yap that is the thing of which i was afraid of. For which condition to size the condenser? i was thinking also to have more condensers and to size them for the worst case or to have a cascade of water coolers in which each dependently of heat consumption the water will flow will bee redirected. At the moment i dont have anything, neither temperatures or load. Nothing, the company manager is negotiating but knowing him, he will get the job and than if i am not prepared - well, the nights will be quite pleasant for work.
I will post a schema today or later tomorrow.
BR and tnx sadgy

[CrankNMelville]

Hey,

I still work on ships and Sedgy is correct, all primary cooling, (except for emergency generators and air compressors,) will be via sea water. The condensers for marine air conditioning and refrigeration systems will generally be either on a sea water system or on a secondary fresh water system.

(The following details apply to primarily cruise ships, but send me a message if you need information on smaller plants on cargo ships, ferries, etc.)
Modern ships tend to use titanium plate heat exchangers for the sea to fresh water cooling while sticking with shell and tube for the condensers. Ships running in cooler climes will sometimes have a separate plate heat exchanger for sea water cooling the chill water plant, if the chillers do not allow free cooling. Small units, like the ice machine you mentioned, will either be air cooled or on a chill water system; most shipyards and owners have tried to get away from large runs of piping on direct expansion installations due to maintenance costs and environmental concerns.

Regarding your problem at hand, when the specifications of a ship are negotiated, part of this includes the operating range. If a supply boat is built for North Sea service, its coolers will not have the capacity for West Africa; because of this, most owners will be very clear with the cooling demands so they do not end up with a ship that they cannot use where they need it or with limited resale value. Generally the basic specifications will include operating conditions that specify sea water temperature and outside air conditions, this allows sizing of the equipment once the heat load calculations come through in the later phases.

I have personally never seen cascading water condensers installed on a ship, most ships try to limit the size of machinery spaces, focusing on areas for the cargo. Please note that materials on a ship are not the same as ashore, and quite a bit more expensive, and that reliability and redundancy will carry more importance due to the lack of a local supply shop wile bobbing about in the middle of the ocean.

[sedgy]

hi crank, very good , enjoyed your facts , sedgy

[s1030]

the heat exchangers of a cooling system ( AC or REF ) are made of special alloys in place where sea water is in contact. Mostly i have seen Cu: Ni (90:10 or 70:30 ) ; Titanium plated PHE(where the budget allows us ) is used in naval ships for condensers and sometimes in evaporators as well.
as pointed out earlier reliability ; redundancy; strength are the main design factors.
Regqrds : S1030

[chandigarhozone]

My query was only one that "is there anybody using R-142b in shipping or some other transport for retrofitting or as new or any means" If any idea pl revert back immediately.

anshu kumar, chandigarh, India
ctc.chd@gmail.com

[s1030]

R 134a is used pre dominantly in shipping and transport refrigeraton.

[Peter_1]

My query was only one that "is there anybody using R-142b in shipping or some other transport for retrofitting or as new or any means" If any idea pl revert back immediately.

anshu kumar, chandigarh, India
ctc.chd@gmail.com
Wrong section and hijacking this thread