Heat Rejection for Condenser

[Samarjit Sen]

I had made an enquiry for procuring a number of Shell & Tube Water Cooled Condensers and have requested the party to let me know the Heat Rejection Capacity of the same. Unfortunately the concerned people are unable to understand.

Could some one help to rephrase the question and seek the capacity of the condenser as the same should be the same as the Heat Rejection of the Compressor. ( Reciprocating )

With best wishes,

[NoNickName]

It's perfectly phrased. I think you shall change the supplier, since they are not understanding a simple concept like "heat rejection".

[lana]

Could some one help to rephrase the question and seek the capacity of the condenser as the same should be the same as the Heat Rejection of the Compressor. ( Reciprocating )

Hi Samarjit Sen,
As NoNickName said, this is very simple and clear. BUT I don't understand your above statement?
Compressor does not have a heat rejection.
I think the question must be : What is the condenser capacity at ....... operating conditions?
For operating conditions you must know the condensing temperature, Water inlet temp.
Hope this helps.
Lana

[NoNickName]

He means: "how to explain that the capacity of the condenser has to be the same than the heat rejection of the compressor". Of course we are in the middle of nowhere since the design condensing pressure and design water temperatures are unknown, but I assume that Samarjit has got the info.

[US Iceman]

If the supplier does not understand how the heat exchangers are rated, run away fast! Find another supplier.

Of course the heat rejection of the compressor is based on a specific operating condition and refrigerant. If the supplier does not understand how to apply their products then I would suspect their ability to build a heat exchanger correctly also.

You do not need this kind of problem as they would not be able to offer any technical support, if required.

[Samarjit Sen]

US Iceman,

You are right. I have got another reputable manufacturer who has offered the right and suitable capacity condenser.

Lana, the Heat Rejection Capacity of a refrigeration system is based on the capacity and the other operating conditions of a compressor. The condenser has to be suitable for this Heat Rejection. This is what I know and then again maybe I am wrong.

Thanks all for your help and assistance.

[lana]

Lana, the Heat Rejection Capacity of a refrigeration system is based on the capacity and the other operating conditions of a compressor. The condenser has to be suitable for this Heat Rejection. This is what I know and then again maybe I am wrong.

Hi Samarjit Sen,
You are right. Qc= Qe + W
Heat rejection = cooling capacity + compressor power consumption
Both Qe and W must be at the operating conditions.
Cheers

[US Iceman]

Something I just thought of related to this thread that should be mentioned...

The condenser heat rejection may have to be modified if a screw compressor is being used. This depends on the oil cooling method, so the equation for condenser heat rejection can be different than that used for a recip. compressor.

[lana]

Hi USIceman,

Absolutely right. When there is an oil injection with an oil cooler then condenser capacity will be less.

Cheers

[Sanjay]

Hi I am a new userRegards