FEED INJECTOR FOR GASIFICATION SYSTEM
TECHNICAL FIELD
The present application and the resultant patent relate generally to
combined cycle power systems and more specifically relates to an improved cooling
water channel for a feed injector of a gasification system that may avoid localized strain
and associated cracking.
BACKGROUND OF THE INVENTION
Combined cycle power systems generally include a gasification system
that is integrated with a gas turbine engine. Known gasification systems convert a
mixture of fuel, airloxygen, steam, and/or other materials into an output of a partially
oxidized gas known as a "syngas." Known gasification systems generally use a feed
injector to supply a mixture stream into a reactor vessel. Known feed injectors may be
exposed to temperature extremes within the reactor vessels. Specifically, the tips of the
feed injectors may be exposed to reaction temperatures that may inhibit effective
operation of the injectors and/or shorten the life span thereof. Further, the feed injectors
generally may be exposed to corrosive elements in the syngas flowing within the reactor
vessel.
In order to protect the feed injectors, known gasification systems may use
a closed loop water supply system to provide cooling water to the feed injector.
Providing cooling water to the known feed injectors, however, may produce areas of
localized strain and associated cracking. Specifically, the metal temperatures between an
internal oxygen passage and an internal cooling water channel about the tip area may be
relatively low as compared to the metal temperatures of the outside face about the
combustion zone. Such temperature differences may be a multiple of about ten (10)
times or so. The stiffness of the metal on the hot side thus decreases as the temperature
increases. The hot side therefore may elongate more than the cool side and result in an
area of high plastic strain therebetween. This area of high plastic strain may result in
cracking or other damage therein. The time and effort required to repair such damage
may be considerable.
There is thus a desire for an improved feed injector design for a
gasification system. Such an improved feed injector design may reduce areas of plastic
strain therein so as to reduce cracking and other types of damage. Reduced cracking may
in turn provide reduced overall system downtime, repair costs, and increased component
lifetime.
SUMMARY OF THE INVENTION
The present application and the resultant patent thus provide a feed
injector nozzle for a gasification system with a reaction zone therein. The feed injector
nozzle may include a number of tubes extending towards the reaction zone. The tubes
may define a number of passages therebetween. A cooling water channel may extend
through one of the tubes. The cooling water channel may include a first side adjacent to
one of the passages and a second side adjacent to the reaction zone. The first side may
include a first side thickness and the second side may include a second side thickness
with the first side thickness being less than or equal to the second side thickness.
The present application and the resultant patent further provide a gasifier
for a combined cycle power system. The gasifier may include a vessel body, a reaction
zone within the vessel body, and a feed injector extending into the vessel body about the
reaction zone. The feed injector may include a nozzle tip with a cooling water channel
therein. The cooling water channel may include a first side and a second side adjacent to
the reaction zone. The first side may include a first side thickness and the second side
may include a second side thickness such that the first side thickness is less than or equal
to the second side thickness.
The present application and the resultant patent further provide a feed
injector nozzle for a gasification system with a reaction zone therein. The feed injector
nozzle may include a number of tubes extending towards the reaction zone. The tubes
may define a number of passages therebetween. A cooling water channel may extend
through one of the tubes. The cooling water channel may include a cool side adjacent to
an oxygen passage and a hot side adjacent to the reaction zone. The cool side may
include a cool side thickness and the hot side may include a hot side thickness such that
the cool side thickness is less than or equal to the hot side thickness.
These and other features and improvements of the present application and
the resultant patent will become apparent to one of ordinary skill in the art upon review of
the following detailed description when taken in conjunction with the several drawings
and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic view of a combined cycle power system and the
components therein.
Fig. 2 is a schematic view of a gasifier with a feed injector and a reaction
zone.
Fig. 3 is a side cross-sectional view of a tip of the feed injector with a
cooling water channel.
Fig. 4 is a side cross-section view of the tip with the cooling water
channel.
Fig. 5 is a side cross-sectional view of a tip with a cooling water channel
as may be described herein.
DETAILED DESCRIPTION
Referring now to the drawings in which like numerals refer to like
elements throughout the several views, Fig. 1 shows a combined cycle power system 10.
The combined cycle power system 10 may include a main air compressor 15, an air
separation unit 20 coupled in flow communication with the compressor 15, a gasifier 25
coupled in flow communication with the air separation unit 20, a gas turbine engine 30
coupled in flow communication with the gasifier 25, and a steam turbine 35. Other
components and other configurations may be used herein.
The compressor 15 compresses an ambient air flow that is channeled to
the air separation unit 20. Alternatively, a compressed flow of air from a compressor 40
of the gas turbine engine 30 also may be used. The air separation unit 20 uses the
compressed air to generate oxygen for use by the gasifier 25. The oxygen flow is used in
the gasifier 25 in generating the partially oxidized syngas. A flow of nitrogen process gas
from the air separation unit 20 also may be forwarded to a combustor 45 of the gas
turbine engine 30 for use in reducing emissions and the like.
Specifically, the gasifier 25 converts a mixture of fuel, oxygen, steam,
andlor other materials into an output of syngas for use by the gas turbine engine 30. The
syngas may flow to the combustor 45 via a cleanup device 50. The cleanup device 50
may separate carbon dioxide and the like therein. The syngas may be combusted in the
combustor 45 so as to produce a stream of hot combustion gases. The hot combustion
gases drive a turbine 55 so as to produce mechanical work. The mechanical work
produced by the turbine 55 drives the compressor 40 and an external load such as an
electrical generator 60 and the like. The exhaust gases from the turbine 55 also may be
channeled to a heat recovery steam generator 65. The heat recovery steam generator 65
generates steam for driving the steam turbine 35. The steam turbine 35 may drive a
further load 70. A further supply of steam may be sent by the heat recovery steam
generator 65 to the gasifier 25 so as to facilitate cooling of the syngas. Other components
and other configurations may be used herein.
Fig. 2 is a schematic view of a solids removal gasifier 100 as may be
described herein. The gasifier 100 may be used with the combined cycle power system
10 described above and the like. The gasifier 100 may include an head end portion 110, a
tail end portion 120, and a substantially cylindrical vessel body 130 extending
therebetween. A feed injector 140 penetrates the head end portion 110 to enable a flow
of fuel to be channeled therein. Specifically, the flow of fuel through the feed injector
140 may be routed through a nozzle 150 thereof. The flow of fuel may discharge into a
reaction zone 160. The reaction zone 160 may be a vertically oriented, generally
cylindrical space that is substantially co-aligned with the nozzle 150. Syngas and
byproducts may be generated within the reaction zone 160. Other components and other
configurations may be used herein.
Fig. 3 shows a tip 170 of the nozzle 150 of the feed injector 140. The tip
170 may include several passages 180 defined therein for the flow of fuel oxygen, fuel,
and the like. The size, shape, number, and configuration of these passages 180 may vary.
The passages 180 may be defined by a number of concentrically arranged annular tubes
190. The tubes 190 may have a largely bayonet-like shape 195. One or more of the tubes
190 may include a cooling water channel 200 extending therein. The size, shape,
number, and configuration of the cooling water channels 200 may vary. Other
components and other configurations may be used herein.
Fig. 4 shows a close up view of a known cooling water channel 200. The
cooling water channel 200 may include a cool side 210 that may be adjacent to an oxygen
passage 220. The cooling water channel 200 also may include a hot side 230 that may be
adjacent to the reaction zone 160. A flow of cooling water 240 flows therein. An area of
maximum strain 250 may be positioned between the cool side 210 and the hot side 230.
As described above, the area of maximum strain 250 may be prone to cracking and the
like. The size and extent of the area of maximum strain 250 may vary.
The cool side 210 may have a cross-sectional thickness 260 that may be
equal to or greater than a hot side thickness 270. Because the hot side 230 faces
temperatures much higher than the cool side 210 by a multiple, the stiffness of the cool
side 210 thus may be much greater than the stiffness of the hot side 230. The hot side
230 therefore may elongate to a degree greater than the cool side 210 so as to create the
area of maximum strain 250.
Fig. 5 shows a cooling water channel 300 as may be described herein. The
cooling water channel 300 also may include a first side 3 10 that may be a cool side 3 15
and a second side 320 that may be a hot side 325. In this example, however, the cool side
3 15 may have a first side thickness 330 that is less than a second side thickness 340 of the
hot side 325. By reducing the first side thickness 330, the stiffness of the cool side 315
also may be reduced. The stiffness of the cool side 315 thus may be closer to the
stiffness of the hot side 325. Areas of similar stiffness therefore may serve to eliminate
or reduce the areas of maximum strain 250. Reducing the areas of maximum strain
should result in low cycle fatigue therein so as to increase the service life of the overall
feed injector 140. Other components and other configurations may be used herein.
It should be apparent that the foregoing relates only to certain
embodiments of the present application and the resultant patent. Numerous changes and
modifications may be made herein by one of ordinary skill in the art without departing
from the general spirit and scope of the invention as defined by the following claims and
the equivalents thereof.

We claim:
1. A feed injector nozzle (150) for a gasification system (100) with a reaction
zone (1 60) therein, comprising:
a plurality of tubes (190) extending towards the reaction zone (160);
the plurality of tubes (190) defining a plurality of passages (180) therebetween;
and
a cooling water channel (300) extending through one of the plurality of tubes
(190);
the cooling water channel (300) comprising a first side (310) adjacent to one of
the plurality of passages (180) and a second side (320) adjacent to the reaction zone
(1 60);
wherein the first side (310) comprises a first side thickness (330) and the second
side (320) comprises a second side thickness (340) and wherein the first side thickness
(330) is less than or equal to the second side thickness (340).
2. The feed injector nozzle (150) of claim 1, wherein the first side (310)
comprises a cool side (3 15).
3. The feed injector nozzle (150) of claim 1, wherein the second side (320)
comprises a hot side (325).
4. The feed injector nozzle (150) of claim 1, wherein the plurality of tubes
(1 90) extends towards the reaction zone (1 60) about a tip (1 70) of the feed injector nozzle
(150).
5. The feed injector nozzle (1 50) of claim 1, wherein the one of the plurality
of passages (1 80) comprises an oxygen passage (220).
6. The feed injector nozzle (150) of claim 1, wherein the cooling water
channel (300) comprises a flow of cooling water (240) therein.
7. The feed injector (150) of claim 1, wherein the plurality of tubes (190)
comprises a bayonet-like shape (195).
8. The feed injector nozzle (150) of claim 1, wherein the first side thickness
(330) minimizes an area of strain (250) between the first side (310) and the second side
(320).
9. The feed injector nozzle (150) of claim 1, wherein the first side (310)
comprises a first side temperature and the second side (320) comprises a second side
temperature and wherein the first side temperature is less than the second side
temperature by a multiple.
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