HELP PLZ: Shell & Tube Selection Parameters

[Mahmoud]

Dear All,,

Please help me out to start selection of shell and tube water cooled condensors in order to match it with refrigeration compressors, to make things systamatic and smooth for you i have some parameters am thinking about in mind:

1- Water In/Out
2- Heat of rejection (how can this be related to refrigeration capacity?)
3- Condensing temp. (related to water In/Out).
4- what is the appropriate delta T (Out-In), and what is the standard value.
5- what is the minimum water in temp.?? is there any limitations ? ofcourse not close to zero.
6- what is the appropriate water flow and speed for a selected condenser.

actualy my case that i want to have 15Kw refrigeration @Tsuction -5c, which cond. temp. i shall go throw to select a compressor, and which water in temp. i have to consider, and whicg DT is applicable. in site i have from 15 to 20c water temperature to feed the condensors.

i have noticed that all the manufacturers are stating the refrigeration capacities at 40c cond.

i know it is too much questions, but it is the first time to use water cooled condensing units

please your help.

Thank you..

[NoNickName]

1) water in depends on the source of water (cooling tower, tap water, sea water, dry cooler, etc.). Water out depends on water in and should normally be within +5°K to +10°K from water in
2) heat of rejection is cooling capacity plus power input of the compressor
3) condensing temperature is normally +5°K to +10°K from water out temperature
4) delta T, see above
5) yes, there are limitations depending on the pressure drop of the tube bundle. The lower the DT, the higher the pressure drop. Pressure drop should not exceed 50/60kPa
6) water flow depends on DT and heat rejection.

But for a 15kW condenser I would prefer a PHE

[Josip]

Hello Mahmoud,

Not easy to help but:

Please, try to visit this page and download selection program:

http://www.flatplate.com/downloads/

or come here and check for literature:

http://www.flatplate.com/literature.htm

Hope you'll find what your'e looking for

Seems very interesting site for other RE guys

Come back with comments

Best regards,

Josip

[Raj Pujar]

Hi Mahmoud,

The italian is right on the money,

When selecting condensing temperature add your temperature difference(TD) across the coil to the ambient temperature.ie, Ambient+TD=Condesing Temp
Depending on the client and application the TD varies from +5K to +10k

Delta T is = Condensing Temp - Liquid Temperature
This is useful when you using PHE.

I hope this would help you.

[Samarjit Sen]

Hello Josip,

The person is interested in information a shell & tube condenser. Flatplate has PHEs. Standard Refrigeration, USA and Alfa Laval, has some good information on Shell & Tube Condenser. I feel nonickname has answered all the informations.

Where are you now?

[Josip]

Hi, Samarjit Sen

Hello Josip,

The person is interested in information a shell & tube condenser. Flatplate has PHEs. Standard Refrigeration, USA and Alfa Laval, has some good information on Shell & Tube Condenser. I feel nonickname has answered all the informations.

Where are you now?

.......that is one old post, hope he succeed.....it is not so difficult when you have so many friends here on RE forums...

Back home, some small jobs around and rest

Best regards, Josip