Chiller barrel replacement?

[michaele]

I have a 150 ton chiller with air cooled condenser that has a 24 year old barrel. The water treatment tests good.ASHRAE gives the average life of a barrel of 24 years. We have not done an eddy current test. I think the baffles inside may be corroded because I cannot get my Delta T more than 5 degrees, no matter how I try to balance the water flow. I am thinking of putting this in our budget for next year because if it goes out, the building has 5 stories of tenants and the windows don't open. I replaced one compressor and rebuilt the other one 2 years ago. Any suggestions.

[sedgy]

michaele, wether its next year or the year after, its going be changed , it cannot last for ever , are you going to change it to air cooled aswell ? sedgy ,

[frank]

Have you thought about fitting a brazed plate heat exchanger instead?

[michaele]

michaele, wether its next year or the year after, its going be changed , it cannot last for ever , are you going to change it to air cooled aswell ? sedgy ,

I hadn't considered converting to a DX coil instead of a barrell if that is what you mean. It is interesting to think about. I don't have the knowledge to design the coils for the capacity or staging. The chilled water system has given us good service over the years.

[michaele]

Have you thought about fitting a brazed plate heat exchanger instead?

I have not thought about that either. There again, I would have to research this. Could it be more efficient or cost effective?

[frank]

Here's a link http://www.brazetek.com/

[aramis]

Comparing PHE with S&T they are more efficient in certain aspects like much larger area/volume ratio, weight full less than 50%, use 1/10th water, less refrigerant, about the same width, 1/5th in length, about twice as tall though and very little service space, less fouling, no stagnation points.

They do have some drawbacks, the one I miss most is literature. There is not a TEMA for PHEs. Less rugged, You need better filters, water-side pressure drop is larger, flow requirements more stringent. BPHE cannot be fixed.

But anyway Frank´s idea is very good.

[Magoo]

Have you checked the partitions in water boxes, could be a problem of bypass giving low delta T.
A lot of S&T vessels have plastic baffles internally on the water side.