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Tycho
25-01-2013, 06:20 AM
http://www.worldfishing.net/export/ice-and-refrigeration/new-rsw-technology-launched

This is really interesting, 12 years ago the Flux chillers reduced the NH3 charge from 1100 kg in a 1000 kw system to 250 kg, and now a system with the same capacity can run on an 80 kg charge :)

Brian_UK
25-01-2013, 08:48 PM
More tonnage for fish then. :)

Looks a good piece of equipment too.

Tycho
26-01-2013, 12:30 AM
the one in the picture is the prototype, with 400kw cooling capacity.
we had it running in our workshop for a few months, and three weeks ago it was installed on a ship.

To quote R. J. Mitchell "It is not good enough to follow conventional methods of design.
It is essential to invent and involve new methods and new ideas." :)

After delivering close to 200 Optiflux units (spray chillers) the last 10 years, it's time to come up with something new.

The great thing about the new chillers is that not only is the charge reduced, but there is no need for a refrigerant pump, so it can be made more compact

Nico
11-02-2013, 08:00 AM
How do they do it Tycho, do you know that?
Is it better evaporator or condenser heat exchanger or a beter separator.

My experiance with RSW dates from few years ago with four 1.2MW NH3 spray type chillers on a ship
The level control was high side float valve and besides the droplets on the pipes (both evaporator and condenser) just few liter Ammonia was used for feeding the pump.
The heat exchangers were tilted so that all refrigerant quickly ran down the pipes and to one side of the shell into the drain dome.
I was impressed how efficient they worked.
I don't know how much Ammonia we used for the chillers because we took almost 40ton on board for the plate freezers and carco holds and tapped from them, but I got the impression that it would be less than 100kg per chiller, much less than you quote for the flux chillers and even comparable with the new type that you mention.
It required huge space though.

In my opinion one of the huge advantages of the spray chiller is that you can reduce capacity from full load to zero load simply by switching off the pump. Therefore we could run at -2C (sea) water out without having (risking) trouble freezing the chiller.
We measured -2.4C water out when we put it to the test, but than after few minutes the water flow became less. My eyes popped out when we got those results. Give it 0.2K measure foult but we could repeat that with all four chillers with each own PT1000 in water outlet.
The pump would than switch off on the flow switch, and seconds later full flow was restored.

Defenitely those were the easyest and most controllable chillers I've ever commissioned.

Nico.

Tycho
12-02-2013, 09:25 PM
How do they do it Tycho, do you know that?
Is it better evaporator or condenser heat exchanger or a beter separator.

My experiance with RSW dates from few years ago with four 1.2MW NH3 spray type chillers on a ship
The level control was high side float valve and besides the droplets on the pipes (both evaporator and condenser) just few liter Ammonia was used for feeding the pump.
The heat exchangers were tilted so that all refrigerant quickly ran down the pipes and to one side of the shell into the drain dome.
I was impressed how efficient they worked.
I don't know how much Ammonia we used for the chillers because we took almost 40ton on board for the plate freezers and carco holds and tapped from them, but I got the impression that it would be less than 100kg per chiller, much less than you quote for the flux chillers and even comparable with the new type that you mention.
It required huge space though.

In my opinion one of the huge advantages of the spray chiller is that you can reduce capacity from full load to zero load simply by switching off the pump. Therefore we could run at -2C (sea) water out without having (risking) trouble freezing the chiller.
We measured -2.4C water out when we put it to the test, but than after few minutes the water flow became less. My eyes popped out when we got those results. Give it 0.2K measure foult but we could repeat that with all four chillers with each own PT1000 in water outlet.
The pump would than switch off on the flow switch, and seconds later full flow was restored.

Defenitely those were the easyest and most controllable chillers I've ever commissioned.

Nico.

The flux is a spray chiller, but the drop leg is in the center and the cooler is "level" :)

We have them with both high side float valves and akva, depending on what the customer wants.

Not sure what kind of equipment you had, but it sounds huge, switching off the pumps on the spray coolers will cause the compressors to shut down on LP within 20 seconds and even if you switch the pumps back on, you have agitated the ammonia in the drop leg so much that the pumps will cavitate and can't get the pressure back up fast enough.

if the chillers you had were 1.2 Mega Watt, I seriously doubt you got away with less than 100 kg, unless the chillers where on the same compressors as the freezing system and had a suction pressure regulator.

What kind of ship was it? must have been like a 100 platefreezers on it :)

Nico
13-02-2013, 10:19 AM
The RSW system was lean and clean. Both RSW spray cooler and condenser were with one leg and tilted. Pump short piped direct under the RSW chiller under the machine room floor. Thermo sifon oil cooler direct under the condenser and extended oil piping from compressors. I believe the latter was not approved by Mycom, but worked very good. All together almost no NH3 in condenser and RSW chiller. Just some in the pump piping, liquid line and the oil cooler. You probably right about being more than 100kg as the oil cooler alone was about 80dm3 (50kg) ammonia and the condensers bit far away from the chillers.


Craziest job I ever had Tyco special when considering that I had hardly any experience in the marine sector.
That Chinese ship, you must have heard about it; Panamax oil tanker converted to freezer mother ship.
Huge ship and build in no-time to Russian standards with just few staff and Chinese contractors.
A Marefsol design engineer made the P&ID and selected the components. He also made the layout for the machine room main components and the freezer deck.
I did the (3d) drawings, site supervision and commissioning and than we had an electrician and a programmer. The idea was to put 240 plate freezers, but I could only fit 232.
When I got involved the ship was being stripped and no piping drawings and nine month later we were on our way to the pacific. Insulation work (poor job) was done by the factory personnel during the voyage. All Mycom compressors 26 pc.; 4 for cargo holds, four for RSW and 18 for the freezers.
Startup virtually without a hassle, a miracle to my opinion considering the minimal number of staff and extreme short construction time.

Tycho
14-02-2013, 06:27 AM
10062

*insert expletive* me, the largest system I have worked on on a ship is 12 tons of ***** and 23 plate freezers

Tycho
16-02-2013, 05:21 AM
As of Today we have 36 RSW skids in production, and 10 of those are of the new SX technology, not bad for something we launched 6 months ago :)

And since we launched the skif RSW units in 2000 we have delivered 156 system (that's 1 system commissioned every month for 13 years)

(if this is inappropriate self commercial for the company I work for, feel free to delete above the line)
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How about a bragging/promoting forum where users can post about themselves, the company they work for, or their own company. (no blatant commercials, but a place where a user can have 1 thread about his company to post information)