Gas Discharge To The Atmosphere
From A Pressure Source:
When the gas velocity is
choked, the equation for the mass flow rate is:
or this equivalent form:
[ It is important to
note that although the gas velocity reaches a maximum and becomed choked, the
mass flow rate is not choked. The mass flow rate can still be increased
if the source pressure is increased. ]
Whenever the ratio of
the absolute source pressure to the absolute downstream ambient pressure is
less than [ ( k + 1 ) / 2 ] k / ( k - 1 ), then the gas velocity is non-choked (i.e.,
sub-sonic) and the equation for the mass flow rate is:
or this equivalent form:
where:
| Q
C
A
gc
k
Rho
P
PA
M
R
T
Z | = mass flow
rate, lb / s
= discharge coefficient (dimensionless, usually about
0.72)
= discharge hole area, ft 2
= gravitational conversion factor of 32.17 ft / s 2
= cp / cv of the gas
= (specific heat at constant pressure) / (specific heat at constant
volume)
= real gas density, lb / ft 3 at P and T
= absolute source or upstream pressure, lb / ft 2
= absolute ambient or downstream pressure, lb / ft 2
= gas molecular weight
= the Universal Gas Law Constant = 1545.3 ft-lb / ( lbmol ·
°R )
= gas temperature, °R
= the gas compressibility factor at P and T
(dimensionless)
Damage line Gas Loss calculation
|
https://drive.google.com/file/d/1eorVzInCN3csoSwYMm8duU4M-bS8iW96/view?usp=sharing
