Methods of Improving Boiler Efficiency

With the rising cost of fuel prices, industries thatboiler corrosion and scaling.As steam is generated
use steam boilers for heating or power generationfrom the evaporation of water, the remaining
are hard pressed to operate at peakwater in the boiler becomes more and more
efficiencies.While steam consumption, leakages,concentrated. This must be drained away during
and other heat transmission losses can contributeblow down.The challenge is to control the draining
to the overall energy bill, this article focuses onto the minimum.Recovering Waste Heat from
the heart of the steam generator - theBlow downSince it is necessary to blow down to
boiler.Controlling the boiler is of utmost importancecontrol the total dissolved solids in the boiler
in any steam generation energy saving program.water, methods can be adopted to recover back
Below are some ways to improve boilersome of the heat from the drained hot
efficiencies:Reducing excess airwater.Blow down tanks, heat exchanger tubes
Installing economizerand pumping arrangements can be fabricated to
Reducing scale and depositsrecover some of the heat back into the
Reducing blow downboiler.Stopping Dynamic OperationWhenever a
Recovering waste heat from blow downboiler starts or stops, a few minutes are spent
Stopping dynamic operationrunning the forced draft fan for purging the
Reducing boiler pressurecombustion chamber of unburnt gases. This is a
Operating at peak efficiencynecessary step for the safe operation of a
Preheating combustion airboiler.During this time the heat from the boiler
Switching from steam to air atomizationwater in the shell or tubes will be lost to the
Switching to lower cost fuelpurging air.To avoid this type of losses, it is better
Reducing Excess AirBy far the most commonto maintain a steady firing condition in the
reason for energy inefficiencies in a boiler can beboilers.Reducing Boiler PressureBy reducing the
attributed to the use of excess air duringboiler pressure, some of the heat losses through
combustion at the burners. When there is moreleakages or transmission may be reduced slightly.
air than is required for combustion, the extra airHowever there can be problems with the boiler
becomes heated up and is finally discharged outwith reduced pressure. The boiler circulation may
to the atmosphere. However, there are reasonsbe upset and the steam lines may have
for putting in some extra air for combustion - toinsufficient capacity and flow to transport the low
compensate for imperfect burner fuel-air mixingpressure steam.Operating at Peak EfficiencyWhen
conditions, air density changes, control systemoperating two or more boilers, improved
"slop", burner maintenance, fuel composition andefficiency can sometimes be obtained by unequal
viscosity variation, and imperfect atomizing steamsharing of the load so that the combined load
or air controls for burners.Adjusting the fuel-airoperates at peak efficiency.Preheating Combustion
ratio for combustion can be quite tricky. If theAirAny heat loss from the skin of the boiler to
fuel is too much as compared to the air,the boiler room can be utilized back for
incomplete combustion occurs. This will give rise tocombustion. By preheating the intake air the
carbon soot deposits inside the combustioncombustion in the furnace becomes more
chamber or even over the boiler tubes.Theefficient.Switching from Steam to Air
consequences of having soot deposits over theAtomizationFor burners with steam atomization,
heat transfer surfaces and the potential of havingswitching to air atomization will naturally result in
explosive flue gases inside the boiler are muchless steam consumption overall and better boiler
worst than losing a slight amount of energyefficiencies. This is only applicable for heavy fuel oil
through the exhaust stack. Therefore, manyburners.Switching to Lower Cost FuelWhen
boiler operators choose to adjust their burners tocomparing natural gas and fuel oil, if the cost is
be slightly on excess air.Installing EconomizerThis isthe same or more per BTU delivered, switch
only appropriate if there are insufficient heatover to fuel oil.The reason for this is that in the
transfer surfaces in the boiler. The economizercombustion process, hydrogen combines with
tubes may contain either circulating boiler water oroxygen to form water. The latent heat of
circulating feed water. Because the temperaturevaporization is lost when water vapor leaves the
of the exhaust gases can be quite high, theboiler stack.Fuels like natural gas with higher
economizer tubes may be fitted with safetyhydrogen to carbon ratio will lose this heat more
valves to avoid over-pressure damage. Alsothan those with lower hydrogen-carbon ratio like
temperature control of feed water is required tofuel oil.However one must also recognize that
prevent pump airlock. To avoid corrosion, carefulthere will be increased maintenance, operating
design is needed to ensure that the exhaust fluecosts and greater need for more excess air in
gas temperature does not drop below the deworder to achieve complete combustion for fuel oil.
point.Reducing Scale and DepositsFor any boilerIn addition, soot deposits and incomplete
operation, this is a must. The safety of the boilercombustion might also affect the overall
is at stake. Any scale or deposits will lead tocosts.Some of the ways mentioned above may
reduced heat transfer that will eventually lead tonot be feasible at all for your plant. Each of them
overheating, reduction of mechanical strength ofmay result in only a few percentage points of
the steel and finally to bursting.This should alreadyboiler efficiency improvement. However, if carried
be in the normal daily procedure of boilerout carefully and with the proper tools and
operation.Reducing Blow downBlow down of boilerinstruments, they do add up to huge savings.Many
water is discharging hot water into the drains.years of working experience in Marine, Facilities,
However, blow down is necessary to maintain theConstruction has given the author material for
boiler water concentration of dissolved solids thatwriting e-books
are necessary for conditioning the boiler water.and articles related to engineering, and
The dissolved solids are necessary for preventingmanagement.