UFC 3-240-13FN
25 May 2005
c) The quantity of makeup water is calculated:
M = (%M/100) x F
or (28/100) X 5.3 kg/s (42,105 lb/hr)
M = 1.5 kg/s (11,789 lb/hr)
d) The quantity of condensate return is calculated:
EQUATION
R = F - M = 5.3 1.5 = 3.8 kg/s (30,316 lb/hr)
(13)
3-1.6.3
Difference Between Amount of Steam Produced and Amount of
Condensate. The difference between amount of steam produced and the amount of
condensate returned represents the combined loss from the system of both steam and
condensate. These losses may result from leakage of steam, consumption of steam by
the process equipment, leakage of condensate, or deliberate discharge of contaminated
condensate. The total water loss can be calculated:
EQUATION
L=ER
(14)
where
L = total steam and condensate losses, kg/s (lb/hr)
E = steam generated, kg/s (lb/hr)
R = condensate return, kg/s (lb/hr)
EXAMPLE 3-3:
a) The steam losses from the boiler described in Examples 3-1 and 3-2 can
be calculated:
EQUATION
L = E - R = 5.0 3.8 = 1.2 kg/s (9684 lb/hr)
(15)
b) This relationship and the information from the previous examples are
presented in Figure 3-9.
3-1.6.4
Basis for Evaluating Boiler System Efficiency. A
good basis for
evaluating boiler system efficiency can be developed by monitoring the system's water
conductivity values, measuring the quantity of steam generated, and performing the
required calculations after a regularly scheduled interval of time. An increase in steam
loss may indicate a new leak, a size increase in existing leaks, a new consumption of
steam, or condensate losses. Additionally, calculations of boiler system efficiency can
provide a good basis for estimating savings in steam cost resulting from maintenance
efforts to reduce steam and condensate losses.
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