3 replies to this topic

[Mathi]

What are the criteria of rating an air-cooled exchanger?

When I read certain articles, I got the idea that the following parameters shall be checked. They are air face velocity and pressure drop across the tube.

Should the velocity across the tube and tube be checked? What other parameters should be checked?

[S.AHMAD]

Dear Mathi, could you please let us know more information for example are you evaluating the performance of an existing air-cooled exchanger or are you designing a new one? Once we the the purpose only then we know what are the essential parameters.

 

Best regards

 

S.Ahmad

[Mathi]

S. Ahmad

 

I am evaluating the performance of an existing air-cooled exchanger. Initially the exchanger operated at 140 barg, as the well pressure decreased, they want to operate it at 100 barg.

 

My Colleague suggested to use the momentum at inlet nozzle and pressure drop across the tube.

 

Your comments are much appreciated.

[S.AHMAD]

Lower operating pressure means a set of new operating conditions.1. What important is to check whether the existing air cooled exchanger has sufficient surface area to cool down the stream. The process data that is essential for rating an existing  exchanger is the flow rate, gas and liquid properties and the new operating temperatures. We also need the exchanger datasheet.The flow rate and gas composition is affecting the heat transfer coefficient and the temperature shall change the LMTD Flow rate and temperature shall change the heat duty. 

 

Based on existing data determine air flow rate from heat balance and determine the operating fouling factor. That means you need to do performance test run on existing cooler.

 

 

S.ahmad