1 reply to this topic

[waqaskhan746]

Dear All,

 

I am working as a process engineer in a gas processing  plant.Our plant is designed to process 30 MMSCFD natural gas .It has two units one is Amine (MDEA) based gas sweetening and other is TEG based Gas Dy-hydration Unit.We are going to relocate this Amine Gas Sweetening plant to some other place which has kind of same day temperature while wind velocity at the new site is almost 100mph. The night temperature in summer is quite low at the night due to its only 20KM distance from the sea.There are installed shell and tube heat ex-changers to cool down the gas as well as Lean Amine.

 

My main question is about finding the right amount of flow rate keeping in mind the already designed cooling tower system.We have a cooling tower whose refrigeration capacity is 750 Tons.

I am sharing the re-boiler heat duty as well the heat duties of other heat ex-changers involved in the process system.There are three heat ex-changers which are installed in cooling tower ;

 

1. Lean Amine Cooler with water as cooling medium.The design sheet is attached with same name.  Heat Exchangers of Amine Unit Data Sheet.pdf   277.41KB   45 downloads
2. Amine Re-flux Condenser .The design sheet is present in   Heat Exchangers of Amine Unit Data Sheet.pdf   277.41KB   45 downloads
3. Sweet Gas Cooler.The design sheet is present in   Heat Exchangers of Amine Unit Data Sheet.pdf   277.41KB   45 downloads

I am also attaching the P&IDs of the amine unit on which the operating/design parameters of temperature,pressure and heat duty are given.

 08002-5006-Rev 2.pdf   386.38KB   25 downloads  08002-5011 Rev 2.pdf   479.08KB   20 downloads  08002-5012-Rev 2.pdf   408.99KB   16 downloads  08002-5013-Rev 2(0).pdf   372.96KB   18 downloads  08002-5013-Rev 2.pdf   359.75KB   21 downloads  08002-5014-Rev 2.pdf   384.71KB   17 downloads

 08002-5015-Rev 2.pdf   217.97KB   17 downloads

 

Now my question is that what should be the water flow rate in the supply header of cooling tower.The cooling tower is placed 150 ft away from the ex-changers.Will the cooling tower of 750 Tons capacity enough to achieve the required parameters as per data sheet of ex-changers.We have Pump capacity of circulating 1200 meter cube flow per hour.How many US gallons will be required as Make-up water.We have RO Water system of 10 m³  capacity.

 

Please suggest some other necessary information you think regarding relocation of  plant should be under consideration. 

 

 

Attached Files

•  Operating Philosphy.docx   17.22KB   22 downloads
•  Amine Plant General Data.docx   28.47KB   20 downloads

[breizh]

Hi ,

A few pointers :

 

*Based on energy balances on your HX , calculate the total amount of water needed for cooling ( include a safety factor ).

 

*Take into account your location , the temperature changes during the year and request a proposal from cooling tower vendors .

 

Regarding Make up water, it depends very much about the quality of your water , the chemical treatment (Blow down)and weather conditions (evaporation). Request a proposal from Chemical treatment vendors

and guarantees about performances ( number of cycles , chemical dosage)

 

Note : cooling towers are not that expensive , consider spare pumps .

 

Good luck,

 

Breizh

Edited by breizh, 05 July 2019 - 09:06 PM.