Retrotec USACE User Manual
Page 190
D60 ENERGY & PROCESS ASSESSMENT PROTOCOL
D.4.1.28 Use of a Boiler Having an Effi ciency Less Than 70%
(Ineffi ciency)
Figure D103. Low-effi ciency old boiler still
in use that has been converted from coal to
burning natural gas.
Figure D104. Old burner with low effi ciency.
Today’s boilers have effi ciencies of operation in the range of 80–95%. Some
small condensing design boilers have peak effi ciencies over 97%. Larger fi re
tube boilers have effi ciencies of 84% throughout their operating range. Water
tube boilers typically perform in the 80% effi cient range. Boilers found to have
an effi ciency of less than 70% (e.g., Figures D103 and D104) either can be
made to perform better or are good candidates for replacement.
D.4.1.29 Use of Steam to Atomize Oil (Ineffi ciency)
Figure D105. Oil-fi red boiler with compressed
air atomization.
Some boilers fi red using fuel oil use burners that atomize the fuel; the use of
steam is one option for accomplishing this. This is done mainly for convenience;
the use of compressed air is more effi cient (Figure D105). Steam atomization