Code Manual for CONTAIN 2.0 - Federation of American Scientists

Counterflow Heat Exchanger Effectiveness. The counterflow heat exchanger effectiveness E (Figure
12-7c) is given by
E=
1 - exp[-Ntu ( 1 - CR)]
1 - CR exp[-Ntu ( 1 - CR)]
(12-30)
Parallel Flow Heat Exchanger Effectiveness. The effectiveness E for the parallel flow heat
exchanger (Figure 12-7d) is modeled in two regimes depending on the value of CR. If ICR-1 I <
0.002, then E is given by
E=
Ntu
1 + Ntu
Otherwise, E is given by
E . 1 - exp[-Ntu (1 + CR)]
I+CR
12.5 ~iauid Tra.rmort Svstem ComDonents
(12-31)
(12-32)
The models for the liquid transport system components used with ESFSor on a stand-alone basis are ~
described in this section. Models for pumps, valves, orifices, pipes, water storage tanks, and pool
overflows are included. These components provide sources and sinks of coolant for the ESF models
(fan coolers, ice condensers, and containment sprays). Certain liquid transport components can also
function independently from the ESFS. Note that the flow through all components except the WST
and overflow model is drawn from the bottom of the pool in the inlet cell.
12.5.1 Pumps
Mechanical pumps are used to circulate the containment building sump pool water up to the
containment spray headers. The pump can be used in one of two types of systems:
● When used by itself, the pump controls the flow of coolant liquid from one cell pool to
another. The flow is directed from cell “iclin” to cell “iclout.”
● When used in conjunction with a containment spray, the pump controls the flow of
recirculated water from a pool to the sprays. When it is used in this mode in conjunction
with a WST, the recirculation flow does not start until the WST supply is exhausted. The
user must specify “pmpmdt,” the pump flow rate. A sample input is shown in Section
14.3.3.4.
R O 12 24 6/30/97