MIL-HDBK-1003/6
Table 2 (continued)
Advantages and Disadvantages of HTW Plants and Steam Plants
+)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))),
*
*
High Temperature Water
Steam
*
*
Disadvantages
Disadvantages
*
*
*
* 1. Primary and secondary pumping
1. Condensate losses in
*
*
required to assure proper heat
distribution range from
*
*
distribution.
12 to 25 percent minimum.
*
*
*
* 2. Proper operation of system
2. Oxygen and bicarbonates in
*
*
depends on artificial
the feedwater can result in
*
*
pressurization. Loss of
corrosion in the condensate
*
*
pressurization causes shutdown.
pipe. Adequate water
*
*
treatment is required to
*
* 3. Steam driven auxiliaries
prevent premature failure of
*
*
not practicable.
the condensate system.
*
*
* 4. Strainer or sediment trap
*
3. Steam boiler requires
*
*
required at inlet to generator
expensive steam drum,
*
*
to prevent solid impurities
extensive feedwater system.
*
*
from entering the generator.
*
*
4. Inadequate pressure at end
* 5. Flashing of water on reduction
*
of steam main will cause
*
*
of pressure in piping system
insufficient quantity of
*
*
can cause cavitation and water
steam for user.
*
*
hammer.
*
*
5. Generally requires more
* 6. Water flashing to steam
*
excavation for underground
*
*
on rupture can result in
systems due to required
*
*
an extremely violent and
pitch of lines.
*
*
dangerously explosive action
*
*
throughout the system.
6. Valves, traps, and strainers
*
*
are sources of steam loads.
* 7. Under constant flow conditions,
*
*
*
high return-water temperatures
*
*
can result at low load conditions,
*
*
thus causing additional thermal
*
*
losses.
*
*
* 8. Heat exchangers are usually
*
*
*
required at end usages of HTW.
.))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))-
11
Previous Page
