MIL-HDBK-1003/7
Section 12.
WATER SUPPLY, MAKEUP, AND TREATMENT
Water Supply. Raw water is required for supply to water treatment equipment
12.1
for boiler-turbine cycle water fill and makeup, water treatment equipment backwash,
plant service water, domestic (potable) water, ash conditioning, cooling tower system
fill and makeup, and fire protection. Consider the use of a raw water storage tank if
necessary to back up any uncertainties in water supply or for fire fighting. Provide
in-plant overhead tank or outdoor elevated tank for pressurization of distribution
system, or consider the use of a pneumatic ground floor level pressurized system. For
additional information see MIL-HDBK-1003/6, MIL-HDBK-1005/7, Water Supply
Systems.
12.2
Water Makeup
Cycle Makeup. Boiler-turbine cycle water makeup is a requirement and
12.2.1
continuous demand when the boiler-turbine cycle is in operation. Normal operation of
the power plant will usually require an actual condensate makeup rate to the cycle of
about 0.5 percent plus the makeup required for steam atomization of oil burners, steam
operated soot blowers, and condensate losses in a process or facility heating system
which is supplied with steam from the boiler-turbine cycle. The design of the makeup
system should be based on a demand of 1.5 percent of the main steam flow to the turbine
to provide for condensate losses from the cycle, plus steam usage for oil atomization
and steam soot blowers, plus process or heating system steam and condensate losses. For
additional information, see MIL-HDBK-1003/6.
Cooling Tower Makeup. Makeup water to a cooling tower cooling water system is
12.2.2
required to replace losses from evaporation, drift, and blowdown. Drift loss from a
mechanical draft tower will range from a minimum of 0.03 percent to a maximum of 0.2
percent of the cooling water flow rate. The blowdown rate will depend on the number of
concentrations of total dissolved solids to be maintained in the cooling water. The
relationships of these variables are as follows:
EQUATION:
Drift + Blowdown = Evaporation / (No. of Concentrations -1)
(12)
EQUATION:
Makeup = Evaporation + Drift + Blowdown
(13)
For additional information relative to cooling towers, see para 12.7.
Water Treatment. Water treatment equipment will be required to provide cycle
12.3
water fill and makeup of suitable quality. The final quality will depend on the
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