MIL-HDBK-1003/6
EQUATION:
V2 = Max Supply Water Expansion + Max Return Water Expansion
(7)
+Q
S,
+Q
S,
* LWmaxst - LWminst
* LWmaxrt
LWminrt *
*
-
S)))))))))))))))))Q *
V2 = cc * SD
*S)))))))))))))))))))))Q*
+
(8)
EQUATION:
S min
S
S
Dminrt *
maxst
*
*
* Dmaxrt
D
st
.Q
S-
.Q
S-
where:
LWmaxst = Lb of water at maximum supply temperature
LWminst = Lb of water at minimum supply temperature
SDmaxst = Specific Density at maximum supply temperature
SDminst = Specific Density at minimum supply temperature
LWmaxrt = Lb of water at maximum return temperature
LWminrt = Lb of water at minimum return temperature
SDmaxrt = Specific Density at maximum return temperature
SDminrt = Specific Density at minimum return temperature
Supply water volume = the volume from the generator outlet, through
the supply distribution system and the heat
exchange equipment.
Return water volume = the volume from the heat exchanger outlet,
through the return distribution system,
expansion vessel, pumps, to the inlet side of
the generator.
4.9.4.3
Design Criteria for Steam Pressurized Systems
a) The vertical height of the expansion vessel above the pump
shall be such that the available net positive suction head (NPSH) is not less
then 125 percent of the required NPSH of the pump.
b) Provisions must be made for expansion and anchoring of the
supply and return connections of the expansion vessel.
c) The generator supply piping to the steam-pressurized vessel
should slope upward to allow venting of free gases. Cut-off valves should be
located at the beginning and end of the supply line. Each generator should
have separate supply piping to the expansion vessel.
d) Generator-supply piping entering a steam-pressurized vessel
should be horizontal, with holes or slots to release water, thereby breaking
up steam bubbles and avoiding shocks.
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