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Estimate Depressuring Load When Software Is not

Available

Mojtaba Habibi Process Engineer at Petroleum Engineering and Development Company

(PEDEC)

Dears,

As you kno so!tares like H"#"#, $%&#&M and Pro'&& are idely used !or

depressuriation studies *ut +at to do i! so!tare is not available it+ process engineer

due to any reason

An interesting paper is recently publis+ed in C+emical Engineering journal dated on une

-./0 titled 12apor depressuriation ' concept and implementation1 3+is paper is ritten

 by MrHites+ Pandya

At t+is paper belo e4uation is presented to estimate depressuring load5

6/ 7 (%8M9t) 8 ln (P/9P-)

6+ere5

6/ 7 t+e initial depressuring rate, kg9min

 % 7 t+e initial moles o! vapor in t+e system

M 7 t+e molecular eig+t o! vapor, kg9kmol

t 7 time, min

P/ 7 initial upstream pressure, bara

P- 7 !inal upstream pressure, bara

As per aut+or:s e;planation5

/ 3+is e4uation provides good results !or vapor'only systems

- <or ot+er systems a contingency o! beteen -.=/..> s+ould be applied to t+e

calculated rate, to allo !or uncertainties (!or instance, vapor molecular eig+t c+anges

t+at may result !romli4uid !las+)

0 E4uation is valid only !or systems +ere t+e !lorate !rom t+e depressuriationcalculations is critical

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? &t also assumes t+at temperature, molecular eig+t and compressibility are constant

t+roug+out t+is period

Could you please s+are your e;periences it+ t+is e4uation in terms o! accuracy and

reliability in comparison it+ your cases +ic+ +ave been studied by so!tare

Also anyone t+at does not +ave t+is paper can send me an e'mail !or a copy (My e'mail

address5 mojtaba+abibi/@/Bya+oocom)

*est,

Mojtaba

Estimate Depressuring oad 6+en #o!tare &s not Available Dears,

As you kno so!tares like H"#"#, $%&#&M and Pro'&& are idely used !or

depressuriation studies *ut +at to do i! so!tare is not available it+ process engineerdue to any reason

An interesting paper is recently publis+ed in C+emical Engineering journal dated on une

-./0 titled 12apor depressuriation ' concept and implementation1 3+is paper is ritten

 by MrHites+ Pandya

At t+is paper belo e4uation is presented to estimate depressuring load5

6/ 7 (%8M9t) 8 ln (P/9P-)

6+ere5

6/ 7 t+e initial depressuring rate, kg9min

 % 7 t+e initial moles o! vapor in t+e system

M 7 t+e molecular eig+t o! vapor, kg9kmol

t 7 time, min

P/ 7 initial upstream pressure, bara

P- 7 !inal upstream pressure, bara

As per aut+or:s e;planation5

/ 3+is e4uation provides good results !or vapor'only systems

- <or ot+er systems a contingency o! beteen -.=/..> s+ould be applied to t+e

7/27/2019 Estimate Depressuring Load When Software Is not Available.doc

http://slidepdf.com/reader/full/estimate-depressuring-load-when-software-is-not-availabledoc 3/3

calculated rate, to allo !or uncertainties (!or instance, vapor molecular eig+t c+anges

t+at may result !rom

li4uid !las+)

0 E4uation is valid only !or systems +ere t+e !lorate !rom t+e depressuriation

calculations is critical

? &t also assumes t+at temperature, molecular eig+t and compressibility are constant

t+roug+out t+is period

Could you please s+are your e;periences it+ t+is e4uation in terms o! accuracy and

reliability in comparison it+ your cases +ic+ +ave been studied by so!tare

Also anyone t+at does not +ave t+is paper can send me an e'mail !or a copy (My e'mail

address5 mojtaba+abibi/@/Bya+oocom)

*est,Mojtaba

 

 %avid

 %avid Hoos+mand 

Process ead Engineer at HEDC

Dear Mojtaba,

3+anks !or good in!ormation

As you:ve mentioned t+is e4uation assumed constant temperature +ile in reality,

temperature may varies signi!icantly, ie, depressuriing air !rom 0. bar to bar leads

F.GC reduction o! temperature #o, t+is e4uation is good !or small pressure drop

egards,

Hoos+mand