I am in process of calculating depressurization rate for condensate dehydrator .
LPG condensate composition as follows :

Component Mole %
NITROGEN 0.0009
H2S 0.0009
CO2 0.0028
METHANE 0.0911
ETHANE 0.1548
PROPANE 0.3015
i-A-BUTANE 0.0805
n-A-BUTANE 0.2154
i-PENTANE 0.0503
n-PENTANE 0.0612
n-HEXANE 0.0307
n-HEPTANE 0.0089

I specified the following for the depressurization module in HYSYS:

Total System Volume 87.1 M3
Liquid Inventory 87.1 M3
Wetted Surface area 117.2 M2
Initial Pressure 58.6 BarG
Initial Temperature 37.8 Deg C
Orifice size 400 mm2
Flow equation supersonic
Valve type Liquid
Environmental Factor 1
Heat flux Model API521
PV Work Term Contribution = 93%
Coefficient of Discharge for Orifice = 0.84

Results of simulation showing out let temperature are in negative

Can any facing the same problem... please share your experience

please check the hysys simulation on the hyper link.

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