Note: Descriptions are shown in the official language in which they were submitted.
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COMBUSTOR ASSEMBLY
AND METHODS OF USING SAME
FIELD OF THE INVENTION
[0001] One
embodiment of the present disclosure relates generally to
a combustor assembly, more particularly, but not by way of limitation, to
an improved combustor assembly and method for improving slagging in a
combustor.
BACKGROUND OF THE INVENTION
[0002]
Many power systems have a combustor which is operated by
the controlled combustion of various solid fuel sources or feedstocks to
generate electricity by driving gas turbines.
Examples of solid fuel
sources utilized in the systems are conventional fossil fuels, other
hydrocarbons, and biomass. Examples of biomass include, but are not
limited to sawdust, bark, twigs, branches, and other waste wood,
bagasse, corn cobs, rice hulls, orchard and vine trimmings, and the like.
However, typically, combustion of these fuels is incomplete, producing
large amounts of waste material.
[0003] All
solid fuels contain a mineral fraction that is mostly
non-combustible and produces waste material, such as ash. Incomplete
combustion of biomass produces ash that accumulates on a heat transfer
or interior surface of a combustor. As
molten ash cools, the ash
accumulates on the interior surfaces of the combustion chamber causing
various problems with the operation of the combustor and the power
system. Deposit of formations of ash ("slagging") is one of the biggest
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problems of combustion of biomass. The
ability of a system to
reduce/improve slagging would lead to reduced investment and
operational costs, increased performance efficiency, and reduced
emissions.
[0004] To
this end, although combustor assemblies are known in the
art, further improvements are desirable to improve or reduce slagging in
the combustor and to enhance the combustor assembly for complete
combustion of a fuel source. It is to such an assembly and process that
one embodiment of the present disclosure is directed.
SUMMARY OF THE INVENTION
[0005] A
burner assembly includes a body, a biomass inlet, a primary
air inlet, a gas inlet, and a secondary inlet. The body has a first end, an
open second end, and a center passageway extending therebetween. The
biomass inlet receives biomass such that the biomass inlet is in
communication with the center passageway so that biomass is injected
from the center passageway by the open second end along a tangential
centerline of the body. The primary air inlet receives primary air. The
gas inlet receives a gas. The secondary air inlet receives secondary air.
[0006] A
combustor assembly includes a burner assembly and a
combustor. A burner assembly includes a body, a biomass inlet, a
primary air inlet, a gas inlet, and a secondary inlet. The body has a first
end, an open second end, and a center passageway extending
therebetween. The biomass inlet receives biomass such that the biomass
inlet is in communication with the center passageway so that biomass is
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injected from the center passageway by the open second end along a
tangential centerline of the body. The primary air inlet receives primary
air. The gas inlet receives a gas. The secondary air inlet receives
secondary air. The burner assembly is connected to a combustor.
[0007] A method of operating a combustor assembly. Biomass feed
material is injected into a center passageway of a body of a burner
assembly. Primary air, gas, and secondary air are injected into the body
of the burner assembly. The biomass feed material is injected along a
tangential centerline of the body of the burner assembly into a
combustor.
BRIEF DESCRIPTION OF THE
SEVERAL VIEWS OF THE DRAWINGS
[0008] FIG. 1 is a cross-sectional view of a combustor assembly
constructed in accordance with the present invention.
[0009] FIG. 2 is a cross-sectional view of a burner assembly of the
combustor assembly of FIG. 1.
[0010] FIG. 3 is a front view of a second end of the burner assembly
of FIG. 2.
[0011] FIG. 4 is a cross-sectional view of a portion of a combustor of
the combustor assembly of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Referring now to the drawings, and more particularly to
FIG. 1, shown therein is one embodiment of a combustor assembly 10
constructed in accordance with the present disclosure. The combustor
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assembly 10 includes a burner assembly 12 and a combustor 14. It
should be understood by one of ordinary skill in the art that the
combustor assembly 10 may be utilized in a system having a feed system
and a gas turbine. The feed system may be any such system for feeding
biomass into a system known to one of ordinary skill in the art so long as
the feed system functions in accordance with the present invention.
Further, the gas turbine may be any suitable gas turbine known by one of
ordinary skill in the art. For example, the gas turbine may be a gas-fired
turbine. Also, the gas turbine may have any of a variety of pressure
ratios, for example, gas turbines suitable for use may have pressure
ratios in the range of from about 4:1 to about 20:1. Furthermore, the
gas turbine may be capable of dual firing, wherein the gas turbine may be
fired using an auxiliary fuel, for example, gas, propane, or a liquid fuel.
[0013] Referring now to FIGS. 1-3, generally, one embodiment of the
burner assembly 12 includes a body 16 having a first end 18, a second
end 20, a biomass inlet 22, a primary air inlet 24, a gas inlet 26, and a
secondary air inlet 28 and a powder cone assembly 30. The body 16 may
be any size and shape so long as the body 16 functions in accordance
with the present disclosure. The biomass inlet 22 is provided for receiving
biomass from a feed system (not shown). Biomass may include any
suitable source of biomass, including, sawdust, bark, twigs, branches,
other waste wood, bagasse, corn cobs, rice hulls, orchard and vine
trimmings, sludge, manure, and combinations thereof. In one
embodiment, the biomass supplied to the combustor assembly 10
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includes a wood-based biomass. The biomass supplied to the combustor
assembly 10 may be sized so that it has a major dimension of less than
about 3 millimeters ("mm").
Further, the biomass also may have
moisture content suitable for combustion, for example, the biomass may
be dried so that they have a moisture content of less than about 30%
and, in one embodiment, a moisture content in the range of from about
0% to about 20%. Those of ordinary skill in the art should recognize that
combustion generally may have various feed requirements (e.g., size,
moisture content, etc.). Further, it should be understood by one of
ordinary skill in the art that although biomass is used, by way of example,
as the fuel source for the combustor assembly 10, any known fuel source
may be utilized, such as fossil fuels and the like, so long as the fuel used
allows the combustor assembly 10 to function in accordance with the
present disclosure as described herein.
[0014]
Biomass is fed through the biomass inlet 22 to the biomass
intake tube 32 which is in communication with a substantially center
passageway 34 extending between the first end 18 and the second
end 20 of the body 16 of the burner assembly 12. The position and
configuration of the center passageway 34 of the burner assembly 12
allows for centerline tangential injection of the biomass feed into the
combustor 14. Centerline injection of the feed into the combustor 14
keeps ash off an interior surface of the combustor 14 which improves
slagging in the combustor 14.
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[0015]
Primary air is provided to the body 16 through the primary air
inlet 24 to the primary air intake tube 40 which is in communication with
a primary air tube 42. The primary air tube 42 is in communication with
a primary air register 44.
[0016]
Gas, such as propane, butane, propane-butane mix, methane,
and the like, is provided to the body 16 through the gas inlet 26 to the
gas intake tube 50 which is in communication with a gas tube 52. The
gas tube 52 is in communication with a gas ring 54.
[0017]
Secondary air is fed to the body 16 through the secondary air
inlet 28 to the secondary air intake tube 60 which is in communication
with a secondary air tube 62. The
secondary air tube 62 is in
communication with a secondary air register 64. It should be understood
by one of ordinary skill in the art that the primary air and the secondary
air may be air, pure oxygen, and/or oxygen-enriched air in various
proportions.
[0018] The
primary air register 44, the gas ring 54, and the
secondary air register 64 are disposed in a concentric configuration about
the center passageway 34 (FIG. 3). The concentric configuration allows
for the centerline tangential injection of the biomass feed from the center
passageway 34 into the combustor 14.
[0019] The
powder cone assembly 30 is provided with a rod 70, a
powder cone 72, and a threaded rod 74. The rod 70 having a first end 76
and a second end 78 is substantially disposed in the center
passageway 34 of the body 16 of the combustor assembly 10. The
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powder cone 72 is disposed on the first end 76 of the rod 70. One end of
the threaded rod 74 is connected to the second end 78 of the rod 70 with
a pin 80. The threaded rod 74 is connected to an internally threaded
flange 82 which is connected to a flange 84 disposed on the first end 18
of the body 16 of the burner assembly 12. The distance between the
powder cone 72 and the open second end 20 of the body 16 of the burner
assembly 12 may be varied by moving the threaded rod 74 so that the
rod 70 moves between a first direction and a second direction. In the
first direction, the powder cone 72 moves away from the second end 20
of the body 16 of the burner assembly 12 and in the second direction, the
powder cone 72 moves toward the second end 20 of the body 16 of the
burner assembly 12. It should be understood that the powder cone 72
may be configured in various ways so long as the powder cone 72 is
movable between the first and second directions as described herein.
[0020] The body 16 of the burner assembly 12 is also provided with a
flame detector 90 for monitoring the formation of a stable combustion
region in the burner assembly 12 and a sight glass 92.
[0021] Referring now to FIGS. 1 and 4, broadly, the combustor 14
includes a housing 100 and a chamber 102 having a sidewall 104
disposed in the housing 100. The housing 100 has a first end 106 and a
second end 108. The first end 106 of the housing 100 is provided with an
opening 110 disposed substantially along a centerline of the housing 100
of the combustor 14. The opening 110 substantially tapers outwardly
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from the first end 106 of the housing 100 of the combustor 14 toward the
chamber 102 of the housing 100.
[0022] The second end 20 of the body 16 of the burner assembly 12
and the first end 106 of the housing 100 of the combustor 14 are shaped
and configured so that the second end 20 of the body 16 of the burner
assembly 12 is disposed in the chamber 102 of the housing 100 of the
combustor 14. The second end 20 of the body 16 of the burner
assembly 12 is provided with a flange 112 for connecting to an external
flange 114 extending a distance from the first end 106 of the housing 100
of the combustor 14 which connects the burner assembly 12 to the
combustor 14. It should be understood by one of ordinary skill in the art
that the combustor 14 may be any size and shape so long as the
combustor 14 functions in accordance with the present disclosure as
described herein.
[0023] From the above description, it is clear that the present
disclosure is well adapted to carry out the objects and to attain the
advantages mentioned herein, as well as those inherent in the invention.
While present embodiments have been described for purposes of this
disclosure, it will be understood that numerous changes may be made
which will readily suggest themselves to those skilled in the art and which
are accomplished within the spirit of the invention as disclosed and
claimed herein.
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