Page 64 - Boiler Operator’s Handbook

Operating Wisely 49

Condensate pump pressure: Also called booster pumps, FGR: See recirculated flue gas.
these lift condensate to the deaerator and the dis-
charge pressure relative to plant steam load and Flame signal strength: Upsets in burner conditions and
deaerator pressure is indicative of the condition soot or moisture accumulations on the flame detec-
of the spray valves in the deaerator. The discharge tor are indicated by changes in the flame signal
pressure of condensate return pumps, not neces- strength. Monitoring it can preclude a sudden
sarily in the boiler plant, can reveal steam blowing unexpected boiler outage. Gradual degradation of
through traps connected to the same header. the flame detector can be monitored for guidance
in replacement beyond the normal one year.
Condensate tank temperature: The tank temperature is
a first indicator of excessive trap failures. Once the Fuel oil meter reading: The totalizer should be read
temperature exceeds 200° a trap inspection is war- at the beginning or end of the shift to track how
ranted. When makeup and condensate are blended much fuel was burned each shift. These data are
in the tank, the temperature can indicate the per- essential for calculating evaporation rate and fuel
centage of returns. An upward shift in temperature inventory maintenance. A fuel oil meter reading
of those tanks indicate trap problems. should be taken for each boiler whenever possible
to determine the boiler performance. If there is no
Deaerator pressure: Small variations in the deaerator pres- meter then fuel tank level readings have to be used
sure relative to feedwater temperature or plant steam to determine consumption.
load can indicate problems with the deaerator.
Fuel oil supply temperature: Measured at the inlet of
Draft readings: The draft readings are seldom recorded the pumps it provides an indication of the tem-
by electronic equipment but they are indicative perature in the tank(s) for inventory management
of the internal conditions of a boiler. Variations and detecting leaks in UST’s (underground storage
in draft readings are frequently subtle, occur over tanks). When burning heavy oil the temperature
extended periods of operation, and are load re- after the heaters is monitored to confirm heater
lated so the operator can miss a significant change. operation. Temperature to the burners is critical
Variations relative to load can indicate fireside for proper atomization and it can vary with oil
blockage, loose baffles, loss of refractory baffles deliveries because the viscosity of the delivered oil
and seals. can change.

Drum pressure: For high pressure steam boilers the Fuel oil tank levels: Required for fuel oil inventory man-
drum pressure is indicative of load because of the agement and detecting UST leaks.
drop through the non-return valve, and the super-
heater when equipped. The drum pressure also Gas fuel meter reading: The totalizer should be read
permits a more accurate calculation of blowdown at the beginning or end of the shift to track how
losses. much fuel was burned on that shift. These data
are essential for calculating evaporation rate and
Feedwater pressure: Changes in heating plants with comparing with the gas supplier’s meter readings.
cycling feed pumps indicate problems with the A gas fuel meter reading should be taken for each
pumps or piping. Changes in plants with feedwa- boiler whenever possible to determine the boiler
ter flow control valves are relative to boiler load. performance. If the only meter available is the gas
supplier’s meter, it should be read to monitor con-
Feedwater temperature: The amount of steam a boiler sumption relative to steam generated, heat output,
can generate is dependent on feedwater tempera- degree days, or other measure of performance.
ture. Lower temperature feedwater will reduce
the capacity of the boiler to generate steam. It has Gas supply pressure: The pressure of the gas supplied to
an effect on evaporation rate and overall plant the plant is monitored to confirm the gas supplier’s
performance. The temperature is also indicative of delivery promise. Gas supply pressure should also
deaerator performance. be monitored for possible loss of supply. Gas pres-
sure supplied to each boiler, after the boiler pres-