Page 61 - Boiler plant and distribution system optimization manual
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46 Boiler Plant and Distribution System Optimization Manual
Figure 5.1—A typical steam distribution system used for illustration in this chapter
The steam load on the system in this case is One must be aware of the fact that condi-
100,000 pounds [50 tons] of steam per hour. Total tions in a boiler plant and distribution system are
energy being delivered to the distribution system changing constantly and that instruments either
is 105 million Btus per hour. The cost of steam is don’t exist or have become inaccurate over years
$4.70 per million Btus. in a harsh environment. It was once said by an old
The 600 psi steam has an enthalpy of 1204 and seasoned plant engineer when commenting
Btu per pound. The make-up water for this sys- on his instrumentation: “accurate to two hammer
tem is 62 F [17C], containing 30 Btus per pound. handles—more or less . Numbers have been round-
The energy value for the steam is actually 1174 ed off in this chapter to communicate important
Btu/lb when we subtract the heat value of our information in a less complex way.
“heat-sink”; the 62 F makeup water.
