10 replies to this topic

[Dmitry]

Hello Dear members,

I want to know your advice before going to design and manufacturing company of Dew point unit equipment for natural gas dehydration and remove HC.

We want to install 2 parallel indenting Dew Point Unit with 30 MMSCFD of natural gas. This will be standard units to provide cooling of natural gas from +40 C on inlet to -20 C on outlet at pressure 50 bar.

Each Dew point Unit will have:

- Gas chiller package (gas/propane hiller, gas/gas heat exchanger, LT separator, HC/propane heat exchanger)

- MEG regeneration package (flash tank, regenerator, MEG injection pumps)

But I want to know if we can use only 1 propane compressor package for both Dew Point Units.
Or we need to have individual propane compressor package for each Dew Point Unit.

From my side I think that using 1 compressor for 2 chillers will be difficult since we need to have indenting propane vapours pressure from two chillers and all conditions should be the same on this Dew Point Units

Please let me know next:

1. Is it possible to use 1 propane compressor for 2 chillers?

3. If yes of not what is the advantages and disadvantages of this solution?

One Compressor package will be cheaper.

Thanks,
Dmytro

[Bobby Strain]

It seems that you have gone to significant expense to provide two units. Why jeopardize the dual train by using a single refrigerant unit? It might be worthwhile to have common refrigerant condensers and accumulator, and likely an economizer. Along with two compressors. It's all a matter of reliability vs cost.

 

Bobby

[Dmitry]

Thanks for your comment!

Yes it will be more expensive than one unit. But management want to have two independent Gas treatment lines, it they wanted to have only one compressor package (one compressor run, second stand by)

I know that it's more economic to install one Dew point unit, which is sized for the maximum gas flow rate, but it not my desigion.

I just want to know how these two units will work paralel with one Propane compressor.

If compressor can not work with two chillers than we need to review again design and may be install just one Dew Point Unit with One compressor package (1 compressor run, one stand by)

Regards,
Dmytro

[Bobby Strain]

One compressor will work well with two chillers.

 

Bobby

[Dmitry]

T
hanks for your answer,

However I want to know if we have a different flow of natural gas through ea h gas chiller so we have different heat exchange in each chiller. Will it cause different propane vapours pressure and temperatures?
Please let me know this details if it possible.
How will be we control it?

[Bobby Strain]

You should be asking these questions of your contractor who is designing the units. When you get some information, like P&ID, then we can comment. We are not in the habit of providing free designs. But, we are happy to comment once you complete your work.

 

Bobby

[Dmitry]

You should be asking these questions of your contractor who is designing the units. When you get some information, like P&ID, then we can comment. We are not in the habit of providing free designs. But, we are happy to comment once you complete your work.

Bobby

I have experience with design companies which done design and supply some equipment. So they proposed some equipment for us but it now not work since we did investigated another options. Now we do not want to do such mistake so I want to learn more about possible issues with running two Chillers with one Propane Compressor before going to design company and Manufacturing. If we have another option I want to consider it.

If you can help me I would very glad
Thanks

[Bobby Strain]

You can control the chillers independent of each other. Either level control for a kettle, or pressure control for any type exchanger. It's not rocket science.

 

Bobby

[Dmitry]

You can control the chillers independent of each other. Either level control for a kettle, or pressure control for any type exchanger. It's not rocket science.

Bobby

Thanks for your comments, now I know that I can go to manufacturing company with more background knowledge

[S.AHMAD]

Hi there'

My view is that is is cheaper investment  and better operating/maintenance flexibility to install three smaller compressors  i.e. one spare unit compressor instead of one big one with one spare i.e. two bigger compressors

 

s.ahmad.

Edited by S.AHMAD, 27 January 2016 - 02:14 PM.

[Dmitry]

Thanks for comments