U.S. patent application number 12/729353 was filed with the patent office on 2011-09-29 for method and apparatus for radial exhaust gas turbine.
Invention is credited to Sumedhkumar Vyankatesh Shende.
Application Number | 20110236201 12/729353 |
Document ID | / |
Family ID | 44310843 |
Filed Date | 2011-09-29 |
United States Patent
Application |
20110236201 |
Kind Code |
A1 |
Shende; Sumedhkumar
Vyankatesh |
September 29, 2011 |
METHOD AND APPARATUS FOR RADIAL EXHAUST GAS TURBINE
Abstract
A radial exhaust gas turbine apparatus has a gas turbine engine
that includes a radial exhaust diffuser section and a casing
apparatus consisting essentially of polygonal walls, substantially
straight plates, and substantially straight sidewalls. The casing
apparatus encloses the radial exhaust diffuser section and is
configured to direct at least a substantial portion of the gas
exiting the radial exhaust diffuser section to an exit in the
casing apparatus via an approximately involute path.
Inventors: |
Shende; Sumedhkumar Vyankatesh;
(Bangalore, IN) |
Family ID: |
44310843 |
Appl. No.: |
12/729353 |
Filed: |
March 23, 2010 |
Current U.S.
Class: |
415/208.2 |
Current CPC
Class: |
F01D 25/30 20130101 |
Class at
Publication: |
415/208.2 |
International
Class: |
F04D 29/44 20060101
F04D029/44 |
Claims
1. An involute type casing apparatus for a gas turbine engine that
includes a radial exhaust diffuser, said apparatus comprising: a
turbine engagement wall having an entry opening; an exhaust
diffuser engagement wall spaced a distance from said turbine
engagement wall, said diffuser engagement wall comprising an engine
shaft hole sized and oriented to said radial exhaust diffuser; a
plurality of substantially straight sidewalls coupled to or
adjacent to edges of said turbine engagement walls and to or
adjacent to edges of said exhaust diffuser engagement wall; and a
plurality of substantially planar plates coupled to or adjacent to
other edges of said turbine engagement wall and to or adjacent to
other edges of said exhaust diffuser engagement wall, such that
said substantially planar plates approximate a portion of a cycle
of an involute curve; said apparatus configured to enclose the
radial exhaust diffuser; and the top plate, bottom plate,
substantially straight sidewalls, and substantially straight plates
are engaged so that exhaust from the radial exhaust diffuser exits
the apparatus via an outlet side.
2. The apparatus of claim 1 the wherein the top plate, bottom
plate, substantially straight sidewalls, and substantially straight
plates are engaged by welds.
3. The apparatus of claim 1 wherein the top plate, bottom plate,
substantially straight sidewalls, and substantially straight plates
are engaged by bolts.
4. The apparatus of claim 1 having at least 4 but not more than 12
substantially straight plates.
5. The apparatus of claim 1 having at least 6 but not more than 10
substantially straight plates.
6. The apparatus of claim 1 having 8 substantially straight
plates.
7. A radial exhaust gas turbine apparatus comprising: an inlet
section; a compressor section operatively coupled to the inlet
section; a combustor section operatively coupled to the compressor
section; a turbine section operatively coupled to the combustor
section; a radial exhaust diffuser operatively coupled to the
turbine section; and an involute type casing enclosing a radial
exhaust diffuser, wherein the involute type casing further
comprises: a turbine engagement wall having an entry opening; an
exhaust diffuser engagement wall spaced a distance from said
turbine engagement wall, said diffuser engagement wall comprising
an engine shaft hole sized and oriented to said radial exhaust
diffuser; a plurality of substantially planar plates coupled to or
adjacent to other edges of said turbine engagement wall and to or
adjacent to other edges of said exhaust diffuser engagement wall,
such that said substantially planar plates approximate a portion of
a cycle of an involute curve; and a plurality of substantially
straight plates coupled to said turbine engagement wall such that
said substantially straight plates are adjacent to outer edges of
said exhaust diffuser engagement wall, approximating a portion of a
cycle of an involute curve; wherein the top plate, bottom plate,
substantially straight walls, and substantially straight plates are
engaged so that exhaust from the exhaust diffuser exits the
involute type casing apparatus via an outlet side.
8. The apparatus of claim 7 the wherein the top plate, bottom
plate, substantially straight walls, and substantially straight
plates are engaged by welds.
9. The apparatus of claim 7 wherein the top plate, bottom plate,
substantially straight walls, and substantially straight plates are
engaged by bolts.
10. The apparatus of claim 7 having at least 4 but not more than 12
substantially straight plates.
11. The apparatus of claim 7 having at least 6 but not more than 10
substantially straight plates.
12. The apparatus of claim 7 having 8 substantially straight
plates.
13. A radial exhaust gas turbine apparatus comprising: gas turbine
engine that includes a radial exhaust diffuser section; and a
casing apparatus consisting essentially of polygonal walls,
substantially straight plates, and substantially straight
sidewalls; said casing apparatus enclosing the radial exhaust
diffuser section and configured to direct at least a substantial
portion of the gas exiting the radial exhaust diffuser section to
an exit in the casing apparatus via an approximately involute
path.
14. The apparatus of claim 13 wherein the polygonal walls,
substantially straight plates, and substantially straight sidewalls
are secured by welds.
15. The apparatus of claim 13 wherein the polygonal walls,
substantially straight plates, and substantially straight sidewalls
are secured by bolts.
16. The apparatus of claim 13 having at least 4 but not more than
12 substantially straight plates.
17. The apparatus of claim 13 having at least 6 but not more than
10 substantially straight plates.
18. The apparatus of claim 13 having 8 substantially straight
plates.
Description
BACKGROUND OF THE INVENTION
[0001] The field of the present invention relates generally to gas
turbine generators, and more specifically to involute type casings
for use with radial exhaust gas turbines.
[0002] At least some known gas turbine engines may experience high
pressure losses. Such pressure losses may adversely affect engine
performance and/or engine efficiency. For example, at least some
known radial exhaust gas turbines that include an outer casing may
experience high pressure losses in their exhaust diffuser sections.
Although circular outer casings can be used to reduce this pressure
drop, such casings may be expensive to manufacture, especially for
gas turbines that require large size casings.
[0003] It would therefore be desirable to provide a more efficient
and less expensive casing for use with gas turbines that include a
radial exhaust. In particular, it would be desirable to provide a
casing that reduces pressure losses in the outer casing section
while not being relatively expensive to manufacture. The reduced
pressure losses may enable the gas turbine to provide additional
power augmentation without using any additional fuel, thus
increasing the operating efficiency of the turbine.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one aspect, an involute type casing apparatus for a gas
turbine engine that includes a radial exhaust diffuser is provided.
The apparatus includes a turbine engagement wall having an entry
opening, and an exhaust diffuser engagement wall spaced a distance
from the turbine engagement wall. The diffuser engagement wall has
an engine shaft hole sized and oriented to the radial exhaust
diffuser. The apparatus also includes a plurality of substantially
straight sidewalls coupled to or adjacent to edges of the turbine
engagement walls and to or adjacent to edges of the exhaust
diffuser engagement wall, and a plurality of substantially planar
plates coupled to or adjacent to other edges of the turbine
engagement wall and to or adjacent to other edges of the exhaust
diffuser engagement wall, such that the substantially planar plates
approximate a portion of a cycle of an involute curve. The
apparatus is configured to enclose the radial exhaust diffuser, and
the top plate, bottom plate, substantially straight sidewalls, and
substantially straight plates are engaged so that exhaust from the
radial exhaust diffuser exits the apparatus via an outlet side.
[0005] In another aspect, a radial exhaust gas turbine apparatus is
provided. The radial exhaust gas turbine apparatus has an inlet
section, a compressor section operatively coupled to the inlet
section, a combustor section operatively coupled to the compressor
section, a turbine section operatively coupled to the combustor
section, a radial exhaust diffuser operatively coupled to the
turbine section, and an involute type casing enclosing a radial
exhaust diffuser. The involute type casing has a turbine engagement
wall having an entry opening and an exhaust diffuser engagement
wall spaced a distance from the turbine engagement wall, wherein
the diffuser engagement wall includes an engine shaft hole sized
and oriented to the radial exhaust diffuser. The involute type
casing also has a plurality of substantially planar plates coupled
to or adjacent to other edges of the turbine engagement wall and to
or adjacent to other edges of the exhaust diffuser engagement wall,
such that the substantially planar plates approximate a portion of
a cycle of an involute curve. The involute type casing also has a
plurality of substantially straight plates coupled to the turbine
engagement wall such that the substantially straight plates are
adjacent to outer edges of the exhaust diffuser engagement wall,
approximating a portion of a cycle of an involute curve. The top
plate, bottom plate, substantially straight walls, and
substantially straight plates are engaged so that exhaust from the
exhaust diffuser exits the involute type casing apparatus via an
outlet side.
[0006] In still another aspect, a radial exhaust gas turbine
apparatus is provided. The radial exhaust gas turbine apparatus has
a gas turbine engine that includes a radial exhaust diffuser
section and a casing apparatus consisting essentially of polygonal
walls, substantially straight plates, and substantially straight
sidewalls. The casing apparatus encloses the radial exhaust
diffuser section and is configured to direct at least a substantial
portion of the gas exiting the radial exhaust diffuser section to
an exit in the casing apparatus via an approximately involute
path.
[0007] It will thus be understood that embodiments of involute type
casings are formed by joining different straight sections of metal
sheets. The arrangement when installed on the radial exhaust gas
turbine will reduce the pressure loss in the casing without
increasing the cost of manufacturing the casing. The casing will
collect the flue gas coming out from vanes and direct the flue gas
towards one side. The involute type casing can be manufactured in
right handed embodiments or left handed embodiments based upon
engineering and installation requirements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cut-away view of an exemplary gas turbine
engine.
[0009] FIG. 2 is an oblique triaxial view of an exemplary casing
for use with a radial exhaust diffuser.
[0010] FIG. 3 is an oblique triaxial exploded view of the casing
shown in FIG. 2.
[0011] FIG. 4 is an oblique triaxial view of an exemplary casing
that may be used with a radial exhaust diffuser of a gas turbine
engine.
[0012] FIG. 5 is an oblique triaxial view of the casing shown in
FIG. 4.
[0013] FIG. 6 is a flow chart of an exemplary method for making an
involute casing.
[0014] FIG. 7 is a diagram illustrating an involute curve.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Embodiments of the present disclosure include an involute
type casing for use with a radial exhaust diffuser of a gas turbine
generator. The radial exhaust diffuser, when installed on the
radial exhaust gas turbine facilitates reducing pressure loss in
the casing generally, without increasing costs of manufacturing the
casing. Flue gas discharged from vanes enters the casing and is
directed towards one side of the casing.
[0016] In some embodiments, and referring specifically to FIG. 1, a
radial exhaust gas turbine 100 includes an inlet section 102, a
compressor section 104, a combustor section 106, a turbine section
108, and an exhaust diffuser section 112. FIG. 2 and FIG. 3
illustrate respective triaxial and exploded triaxial views,
respectively, of exhaust diffuser casing 110. In the illustrated
embodiment, exhaust diffuser casing 110 includes a turbine
engagement wall 113 that includes an entry opening 114. An exhaust
diffuser engagement wall 116 is positioned opposite turbine
engagement wall 113 and includes a hole 118 configured to permit
the passing through of an engine shaft and opposite round entry
opening 114. Entry opening 114 is in fluid communication with
exhaust diffuser section 112, as is seen in FIG. 1, and need not be
the same size as engine shaft hole 118. More specifically, engine
shaft hole 118 may be any size relative to entry opening 114. A
plurality of substantially straight sidewalls 120 and an arcuate
wall 122 are welded or bolted, onto or adjacent to, edges 220 and
222 of turbine engagement wall 113 and to edges 320 and 322 of
diffuser engagement wall 116. As a result, engagement walls 113 and
116 are maintained a fixed distance apart. Edges 130 of walls 120
and of wall 122 are also securely coupled together where they
contact. An exhaust side 124 of exhaust diffuser casing 110 remains
open and unobstructed to enable exhaust gas 126 to discharge into
the atmosphere or into any other component.
[0017] FIGS. 4 and 5 illustrate triaxial oblique views of an
exhaust diffuser casing 10. In the exemplary embodiment, casing 10
includes a turbine engagement wall 13 including a substantially
circular entry opening 14. An exhaust diffuser engagement wall 16
is positioned opposite to turbine engagement wall 13 and includes
an engine shaft opening 18 formed opposite entry opening 14. Entry
opening 14 is in fluid communication with exhaust diffuser section
112, as best illustrated in FIG. 1, and may, but need not be, the
same size as engine shaft opening 18. A plurality of substantially
straight sidewalls 20 are coupled to or adjacent to edges 420 of
turbine engagement wall 13 and to edges 520 of diffuser engagement
wall 16. As such, walls 13 and 16 are maintained at a fixed
distance apart. A plurality of substantially straight (planar)
plates 22 of varying widths are coupled to or adjacent to edges 422
of turbine engagement wall 13 or to edges 522, such that walls 13
and 16 are substantially parallel to each other. In addition,
sidewalls 20 are coupled to plates 22 where they contact, and where
plates 22 meet one another. An exhaust side 224 of exhaust diffuser
casing 10 remains open and unobstructed to enable exhaust gas 126
to be discharged to the atmosphere or into any other component.
[0018] In the exemplary embodiment, involute casing 10 is not
arcuate, but rather, the same involute curve is approximated by
wall edges 422 and 522. Involute casing 10 is shaped to channel the
exhaust flow therethrough in a manner that facilitates reducing
pressure drop in diffuser section 112. Moreover, the manufacture of
involute casing 10 is no more expensive than that of current
chambers. A length 722 (shown in FIG. 4) of each plate 22 is varied
as necessary to obtain the desired involute casing profile. In
addition, involute casing 10 may be assembled and used in either a
right hand configuration or a left handed configuration. It should
be noted that FIGS. 2 and 3 illustrate a right handed prior art
configuration, while FIGS. 4 and 5 illustrate a left handed
configuration.
[0019] The involute of a circle around the Z-axis in cylindrical
coordinates (r, .theta., z) is given by parametric equations
written r=.alpha.sec .alpha., .theta.=tan .alpha.-.alpha.,
z=z.sub.0, wherein .alpha. represents a radius of the circle,
.alpha. is a parameter, and z.sub.o is a location of the circle
along the Z-axis. As illustrated in FIG. 7, lengths 722 of each
plate 22 are approximated by the lengths of line segments 752
defined along the involute. In some embodiments, line segments 752
are selected by the intersection of regularly or irregularly spaced
angles in the .theta.-direction with the involute. A number of
plates 22 should be between 3 and about 12 inclusive, to facilitate
optimizing the time and cost of manufacturing. In the exemplary
embodiment shown in FIGS. 4 and 5, eight straight plates 22 are
shown. To ensure a minimal effectiveness, at least 120.degree., but
no more than 210.degree., of a cycle of an involute curve should be
approximated. For the purposes of the claims recited below, each
range recited above is considered to include all subranges. For
example, an apparatus having between five and seven plates and that
approximates between 160.degree. and 210.degree. of an involute
cycle, is considered to be defined by the wider ranges recited
above.
[0020] Plates 22 may include sheets fabricated from any suitable
metallic material and may be either bolted or welded together in
such a manner that eliminates the need to form (i.e., roll) the
sheets into a curved contour.
[0021] In another aspect and referring to FIGS. 4, 5, and 6, in
some embodiments of the present invention, an exemplary method 600
for making an involute type casing 10 for a radial exhaust gas
turbine 100 is provided. In the exemplary embodiment, method 600
includes, fabricating 602 a polygonal first wall 13 that includes
an opening 14 that is sized and oriented to engage a turbine
section 108 of radial exhaust gas turbine 100. First wall 13 also
includes a first set of at least three edges 422 that approximate
between 120.degree. and 210.degree. of a cycle of an involute curve
700 illustrated in FIG. 7. First wall 13 also includes a second set
of other substantially straight edges 420.
[0022] In the exemplary embodiment, method 600 also includes
fabricating 604 a polygonal second wall 16 that includes an engine
shaft opening 18 therein that is sized and oriented to engage a
radial exhaust gas diffuser section 112. Second wall 16 includes a
third set of at least three edges 520 used to approximate the same
involute curve 700 as the first set of at least three edges 422 of
first wall 13. Second wall 16 also includes a fourth set of
straight edges 520 that each have approximately the same length as
a corresponding edge 520 of the second set of edges 420.
[0023] Method 600 also includes fabricating 606 a plurality of
plates 22. Specifically, the number of plates 22 fabricated 606 is
equal to the number of edges in the first set of edges 422. Each
plate 22 has a length 722 that is approximately the same size as a
length 822 of a different edge 422, and all plates 22 are
fabricated with the same width 922.
[0024] In the exemplary method 600, a plurality of sidewalls 20 are
also fabricated 608. More specifically, the number sidewalls 20 is
one less in number than the second set of edges 420. Each sidewall
20 has a width 720 that is approximately equal to the length 820 of
a different edge 420, and a length 920 equal to the width 922 of
plates 22.
[0025] Method 600 also includes affixing 610 each plate 22 at, or
adjacent to, an edge 422 having the same length 822 as the length
722 of the affixed plate 22, and at, or adjacent to, an edge 522
having the same length 1022 as the width 922 of the affixed plate
22.
[0026] In the exemplary embodiment, method 600 also includes
affixing 612 each sidewall 20 to first wall 13 and to second wall
16 between an edge 420 and an edge 520 having the same length as
the width of the affixed sidewall 20. After completion of steps
602, 604, 606, 608, 610, and 612, a casing 10 such as that
illustrated in FIG. 4 and FIG. 5 will be produced.
[0027] In the exemplary embodiment, method 600 can also include
affixing adjacent plates 22, adjacent sidewalls 20, and plates 22
adjacent to straight sidewalls 20. Thus, in this embodiment, first
wall 13 and second wall 16 are parallel to one another, outlet side
224 remains open, and all adjacent edges belonging to separate
structure parts will be affixed to one another.
[0028] In some exemplary methods 600, first wall 13, second wall
16, each sidewall 20 and each straight plate 22 comprise fabricated
sheet metal. The fabricated sheet metal is cut or punched into
predetermined shapes. Additionally, each affixing can include
weld(s), bolt(s), and/or screw(s), in any combination.
[0029] Also in some exemplary method 600, between four and twelve
plates 22, inclusive, are fabricated, or between six and ten plates
22, inclusive, are fabricated, or exactly eight plates 22 are
fabricated. Referring to FIG. 7, each plate 22 has a dimension 752
approximating a portion 750 of an involute 754 of a circle 756. It
is sufficient for involute casing 10 to be configured to enclose a
radial gas diffuser section 112 of a radial exhaust gas turbine 100
and for the approximation of the portion 750 of involute 754 of
circle 756 to guide at least a substantial portion of the gas
exiting radial exhaust gas diffuser section 112 to an exit 224 in
the casing apparatus via an approximately involute path.
[0030] It will thus be understood that an embodiment of involute
type casing is formed by joining different straight sections of
metal sheets. The arrangement when installed on the radial exhaust
gas turbine will reduce the pressure loss in the casing without
increasing the cost of manufacturing the casing. The casing will
collect the flue gas coming out from vanes and direct the flue gas
towards one side. The involute type casing can be manufactured in
right handed embodiments or left handed embodiments based upon
engineering and installation requirements.
[0031] In this written description, it should be understood that
the phrase "equal to," when used in the context of dimensionality,
refers to quantities equal to each other to within standard
tolerances of good engineering practice. Similarly, the verb phrase
"to approximate" refers to an approximation made within standard
tolerances of good engineering practices and any other limitations
imposed, such as requiring a curve to be approximated by a series
of straight lines.
[0032] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they have structural elements that do not differ
from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *