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[chem_buddy]

Dear All 

 

It is a very basic question. However I would like to confirm the method for calculating the Latent heat of vaporization for single component using Hysys.

 

 

Steps by Hysys:

1) Take a stream in Hysys and define the composition and Thermodynamic method.

2) define the relieving pressure as Pset X 1.21

3) Define the mass flow rate as 100 or any mass flow rate is ok.

4) Define the vapor fraction as 0 and get the value of mass enthalpy from properties tab for liquid phase and vapor phase

5) Latent heat of vaporization = dew point enthalpy - bubble point enthalpy

                                               = mass enthalpy of vapor phase - mass enthalpy of liquid phase

 

6) Relieving temperature will be the temperature at relieving pressure and 0 vapor fraction.

 

I think the above method is correct. However your valuable inputs would be highly appreciated.

 

Thanks 

Edited by chem_buddy, 10 March 2015 - 12:15 AM.

[serra]

you can calculate latent heat as difference Hvapor - Hliquid

note that a pure fluid  |td-tb| = 0.000.. K

while for a mixture |td-tb| can be a large value

when sizing a PSV you need to

1) calculate initial conditions

2) calculate the mass flow to discharge, fluid properties etc.

3) size PSV according API or some other code..

 

all these topics have been discussed many times, see for example

 

"http://www.cheresour...-vaporization/"

Edited by serra, 10 March 2015 - 01:38 AM.