Code Manual for CONTAIN 2.0 - Federation of American Scientists

Stage 2 accounts for the flashing because of the source if the BOIL option has been specified.
Otherwise, the amount flashed is set to zero. The amount of pool mass flashing A% is given by
Am . Qp + AQP - (mp+Amp)ht
f
h - hl
V,s
if positive, and the energy carried by the flashed water is
(1 1-34)
AQf = hv,,Amf (11-35)
where QPand ~ are the initial pool energy and mass, respectively, and ~ and ~,, are the saturated
liquid and saturated vapor enthalpy, respectively.
Stage 3 accounts for the vapor taken up by the noncondensable gas bubbles of the vent flow. The
bubble vapor pressure is assumed to be 0.95 times that of the pool vapor pressure at a self-consistent
pool temperature T’ to avoid numerical problems. The pressure in bubbles containing the
noncondensable gases at the pool surface is assumed to be the same as the atmosphere pressure Pi
in the cell i in question. Thus,
0.95 PS(T’) +P~C(T’) = Pi
where P,(T’) the saturation pressure at the new self-consistent
pool, correctly adjusted for the vapor energy removed by
noncondensable gas pressure in the bubble.
(11-36)
equilibrium temperature T’ of the
the bubbles; and P~C(T’)is the
If the BOIL option has been specified, Equation (11-33) combined with the ideal gas assumption
provides the vapor mass in the outflow ~,Ou,
mv,o”t=
MV0.95P$T’)N~C
Pi - 0.95PS(T’)
(11-37)
where M, is the molecular weight of water vapor, and N~C is the moles of noncondensable gas.
Otherwise nqOU~is set to zero.
The linearized energy balance for the suppression pool, taking into account the fact that vaporization
into the bubbles cools the pool and the gas passing through, is given by
mv,out%v@’J = AQ; - (Cp+ cg)ALq
(11-38)
where hCv(T’)is the latent heat of evaporation (~,, - h~,,)evaluated at T‘; AQ~equals AQP- AQ~-
(~ - AI%)L(TP) ~d represents the ch~ges in the POO1energy because OfPrOCeSSeSCOnSidered
in Stage 1 and Stage 2; CPis the specific heat of the pool multiplied by the sum of the pool mass and
any additional mass of vapor condensed in the pool minus any flashed; C~is the specific heat of
O 11 21 6/30/97