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Thanu
05-09-2016, 03:47 AM
Hi All,

I am designing a condensing unit for the industrial air-con. I have a 7 hp compressor with the cooling capacity 19kW and 2 condenser each with 8kW heat rejection capacity.

I have a doubt whether connect the condenser in series or parallel to get more cooling capacity.
kindly request you guide me to design the most efficient one. Thank you

Magoo
05-09-2016, 04:02 AM
Check your figures first as heat of rejection does not add up to refrig capacity plus heat of compression/ motor drawn Kws.

Thanu
05-09-2016, 04:13 AM
Thanks for you kind reply,
The heat rejection of the compressor is 4.2 kW, So total heat needed to rejected from the condensers is 4.2 + 19 = 23.2 kW.

I understand that I can not achieve this 23.2kW Using my condensers. Please let me know series or parallel connection will be efficient.

Greek_engineer
05-09-2016, 06:07 AM
Using parallel scheme it would give you an adnvantage over the cold months of year.

Thanu
05-09-2016, 07:44 AM
Thanks for your information. Here the ambient temperature is around 30C all over the year. Is there any advantage in series scheme?

Josip
05-09-2016, 10:03 AM
Hi, Thanu :)

Welcome to RE forums ... it will be nice to start here
http://www.refrigeration-engineer.com/forums/forumdisplay.php?72-New-to-RE
to introduce yourself to us ... but you can do it at anytime ...


Thanks for your information. Here the ambient temperature is around 30C all over the year. Is there any advantage in series scheme?


check here:
http://docuk.download/allpdf/handbook-of-air-conditioning-heating-and-ventilating-by-eugene-stamper.pdf

or read this ...

https://books.google.hr/books?id=G47biva6gtwC&pg=SA4-PA56&lpg=SA4-PA56&dq=serial+connection+of+condensers+in+refrigeration&source=bl&ots=vN7RwW1eh7&sig=EaPCIodbQ5P8kKI9gRr6ZDr897Y&hl=hr&sa=X&ved=0ahUKEwjJ2MDL5ffOAhXHBiwKHeKGBw0Q6AEIGzAA#v=onepage&q=serial%20connection%20of%20condensers%20in%20refrigeration&f=false

... hope this will help you ...

Best regards, Josip :)

cduque
05-09-2016, 03:04 PM
As a general rule you will have best results with paralel condensers but you will have to be careful with the piping design. Check the recomendations, for example
http://www.evapco.eu/sites/evapco.eu/files/white_papers/piping_131-e_0706.pdf

chemi-cool
05-09-2016, 03:25 PM
It will work but for a short while.
Calculated heat rejection is 23.2kw, you need at least 25kw condenser.
you did not mentioned what refrigerant you use which might require even bigger condenser.
With what you got and your determination to have a go any way, I bring you a few lines from the immortal book "Alice in wonderland.

`"Cheshire Puss,' she began, rather timidly, as she did not at all know whether it would like the name: however, it only grinned a little wider. `Come, it's pleased so far,' thought Alice, and she went on. `Would you tell me, please, which way I ought to go from here?'

`That depends a good deal on where you want to get to,' said the Cat.

`I don't much care where--' said Alice.

`Then it doesn't matter which way you go,' said the Cat."