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crocens
28-09-2011, 04:54 PM
Hi all :)

Once again i ned your opinion.
I have a Brazed plate heat exchanger and i would like to feed it witch refrigerant (R134a) through capillary tube. It will be cooling passing water.

Are there any problem with such solution or do i need TEV?
In adition the water temperature at inlet to exchanger will be always the same, no more, no less (12*C) and flow will be almost constans (it may change up to 20% but in a veery long time.

I would like to be sure that no suprises will occur... :)

Thanks for advice,
Marcin
AlexG
30-09-2011, 02:00 PM
Crocens, condensing pressure must be also constant. And how did u calculated your capillary tube? If your calculation are not precise you will have liquid slugging or high superheat. I think u had better instal TXV.
crocens
30-09-2011, 03:37 PM
yes, I will have constant condensing pressure (condenser inside room with AC and heating)
I have already put capillary tube, in a few hours i will make first tests and we will see what will happen :)
taz24
30-09-2011, 03:41 PM
.

With a capillary tube there is no flexibility. you will have to be very, very exact in
your calculations because if you get it wrong you will either starve the evap or flood liquid back to
the compressor.

If you have the facilities put a reciever in the circuit and fit a TEV.

All the best

taz

.
AlexG
30-09-2011, 05:01 PM
Crocers, inform us about result... By the way what is cooling capacity?
crocens
01-10-2011, 09:46 PM
It works great for me.
I have bought water chiller but i was told it have 3kW of cooling power... but i does not have, only 1,7kW.
So i have to build extra 2.0kW chiller to cool water that next will go to my first chiller (with water tank).
So i can say i builded "pre-cooling" chiller. I always have the same water temperature on inlet to heat exchanger and always the same water capacity (m3/h). And what i can say... few hours of testing, cappilary tube cuting and it works great :)

I need no flexibility, in my aplication there will be no changes (It is a testing equipment and i need this extra chiller for testing only one part (out of 20 others)