Results 1 to 9 of 9
Thread: Chiller selection
-
19-03-2009, 06:58 AM #1
Chiller selection
Hi!
I want to cool the water from 34 degree centigrate to 10 deg centigrate and i want to use flooded chiller for the same. Some body told me that flooded chiller shall not be used for this application. Due to space constraint , i cannot use multiple chiller option . Can any body suggest some solution?? I want to use shell and tube type heat exchanger only .Will it work and if not why??
Refrigerant is ammonia and condensing temperature is 42 degree centigrate.
-
08-06-2010, 10:07 PM #2
Re: Chiller selection
Dear Ambrish_bajpai,
We have experience in using flooded chiller for cooling water, but the main problem for this system is freezing of water in heat exchanger, so you must make strict control system (temperature of water) and system of quick giving hot gas in the heat exchanger. So, thereby you will work without any problem and you will have good result.
-
08-06-2010, 11:15 PM #3
Re: Chiller selection
With proper control, flooded ammonia is the most efficient way to cool this water. You may want to consider PHE as they are generally more efficient, much smaller and hold far lower refrigerant charge.
-
09-06-2010, 06:28 AM #4
Re: Chiller selection
Hi Ambrish,
As suggested above, use PHE type flooded chiller & you will be right. However, your requirement is for 10 deg C, but use good flow & temperature sensors to avoid freezing. I would recommend Alfa Laval PHE or cheaper one available @ www.idmc.coop
cheers
GauravBR
-
09-06-2010, 11:50 AM #5
Re: Chiller selection
If you decide to use a PHE, install a water pressure differential switch for freeze protection. When a PHE begins to freeze, the outlet water temperature goes up a little so a freeze 'stat doesn't work well but the pressure drop increases dramatically which makes a pressure differential switch relaible and workable as freeze protection.
-
09-06-2010, 12:54 PM #6
Re: Chiller selection
10 degC is not difficult to achieve in a heat exchanger without freezing. Any good design should include a low flow sensor to protect the chiller as a well as a low evaporator pressure device.
Th biggest problem is the excessively high inlet temperature of the water. With a flooded chiller design, you can have problems with a high heat flux at the entry pass(es) of the chiller. This can lead to liquid distribution problems in a flooded design. An extremely high boiling rate will cause extreme turbulence on one end of the chiller.
When you have such a high entrance temperature, consider a plate exchanger design or possibly a DX design if it is small enough. Another solution is to use a run-around loop and a blending valve to blend with the high temp water so that the evaporator will not see such high temperatures.
Ken
-
Re: Chiller selection
how much water do you need to chill?
and I would rather go with a spray chiller with NH3 instead of a flooded chiller, but that all depends on the space you have availableLast edited by Tycho; 09-06-2010 at 09:25 PM.
-Cheers-
Tycho
-
07-10-2010, 03:55 PM #8
Re: Chiller selection
Dear Ambrish_bajpai,
I read your thread newly. The sama invstement is planning to our process.
1600 ton/h water will be cooled form 32C to 16C.
Can you transfer your exprience if you made this system for your process ?
-
07-10-2010, 04:42 PM #9
Re: Chiller selection
Alfa laval/ swep/ tranter or equivalent phe chillers are good enough for this application.
But
danfoss/ hansen/ manik make epr valves are a must for safer & efficient operation.
Regards.
Priti
Similar Threads
-
process chiller help
By talon771 in forum IndustrialReplies: 8Last Post: 12-01-2011, 08:42 PM -
DIY aquarium chiller
By BarraCuda in forum Technical DiscussionsReplies: 18Last Post: 06-10-2010, 11:02 PM -
Absorption Chiller VS Mech. Chiller
By Intern in forum IndustrialReplies: 20Last Post: 30-05-2009, 08:31 AM -
York Chiller startup when on Emergency Power
By Apollo10 in forum Trouble ShootingReplies: 3Last Post: 22-12-2008, 07:13 PM -
Trane CVHE 450 R11 Centrifugal Chiller
By albertjoseph in forum Air ConditioningReplies: 4Last Post: 06-10-2008, 03:23 PM