U.S. patent application number 15/278773 was filed with the patent office on 2017-03-30 for vortex generator, and fuel injection system of a gas turbine with such vortex generator.
This patent application is currently assigned to ANSALDO ENERGIA SWITZERLAND AG. The applicant listed for this patent is ANSALDO ENERGIA SWITZERLAND AG. Invention is credited to Madhavan Narasimhan POYYAPAKKAM, Khawar SYED, Yang YANG.
Application Number | 20170089584 15/278773 |
Document ID | / |
Family ID | 54249327 |
Filed Date | 2017-03-30 |
United States Patent
Application |
20170089584 |
Kind Code |
A1 |
POYYAPAKKAM; Madhavan Narasimhan ;
et al. |
March 30, 2017 |
VORTEX GENERATOR, AND FUEL INJECTION SYSTEM OF A GAS TURBINE WITH
SUCH VORTEX GENERATOR
Abstract
A vortex generator, such as for a fuel injection system of a gas
turbine, includes a base area and a vortex generator body extending
in a tapering fashion from the base area with a predetermined
height. A rapid fuel-air mixing at allowable pressure drops for
higher firing temperature gas turbines and within short
burner-mixing length or time scales is achieved by the vortex
generator body forming at least two partial vortex generators,
whereby each of the at least two partial vortex generators has its
own trailing edge.
Inventors: |
POYYAPAKKAM; Madhavan
Narasimhan; (Rotkreuz, CH) ; YANG; Yang;
(Nussbaumen, CH) ; SYED; Khawar; (Oberrohrdorf,
CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ANSALDO ENERGIA SWITZERLAND AG |
Baden |
|
CH |
|
|
Assignee: |
ANSALDO ENERGIA SWITZERLAND
AG
Baden
CH
|
Family ID: |
54249327 |
Appl. No.: |
15/278773 |
Filed: |
September 28, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23R 3/18 20130101; F23R
3/286 20130101; F23R 3/12 20130101; F23R 3/16 20130101; F23R 3/20
20130101 |
International
Class: |
F23R 3/28 20060101
F23R003/28 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 28, 2015 |
EP |
15187052.4 |
Claims
1. Vortex generator suitable for a fuel injection system of a gas
turbine, the vortex generator comprising: a base area; and a vortex
generator body extending in a tapering fashion from said base area
with a predetermined height, said vortex generator body forming at
least two partial vortex generators, whereby each of said at least
two partial vortex generators has its own trailing edge.
2. Vortex generator as claimed in claim 1, wherein said base area
is formed as a triangle.
3. Vortex generator as claimed in claim 1, wherein said at least
two partial vortex generators are arranged at different heights
with respect to said base area.
4. Vortex generator as claimed in claim 3, wherein said at least
two partial vortex generators are arranged one above the other with
respect to said base area, said upper partial vortex generator
having a first height and said lower partial vortex generator
having a second height.
5. Vortex generator as claimed in claim 1, wherein said at least
two partial vortex generators are arranged in a predetermined angle
to each other.
6. Vortex generator as claimed in claim 5, wherein said
predetermined angle between said two partial vortex generators can
vary between 0.degree. and 45.degree..
7. Vortex generator as claimed in claim 1, wherein said at least
two partial vortex generators each have an associated attack and
sweep angle.
8. Vortex generator as claimed in claim 7, wherein said at least
two partial vortex generators are arranged one above the other with
respect to said base area, said upper partial vortex generator
having a first height and said lower partial vortex generator
having a second height, and wherein said upper partial vortex
generator has a higher attack and sweep angle than said lower
partial vortex generator.
9. Vortex generator as claimed in claim 1, in combination with: a
fuel injection means provided between said at least two partial
vortex generators.
10. Vortex generator as claimed in claim 9, wherein said fuel
injection means is located with different distances between said
location and said at least two partial vortex generators.
11. Vortex generator as claimed in claim 1, wherein said at least
two partial vortex generators have a leading edge, and that the
leading edge of said at least two partial vortex generators has a
predetermined shape.
12. Vortex generator as claimed in claim 1, in combination with a
fuel injection system of a gas turbine, comprising: a fuel
injection means configured to include the vortex generator; and a
gas turbine which receives fuel from the fuel injection means.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to vortex generators. It
refers to a vortex generator according to the preamble of claim
1.
[0002] The present invention further refers to a fuel injection
system of a gas turbine with a vortex generator.
PRIOR ART
[0003] A current fuel injection system of a gas turbine with vortex
generators (VGs) mounted on perpendicular flutes is shown in FIG.
1. The fuel injection system 20 comprises a plurality of flutes 23
extending between a lower plate 21 and an upper plate 22. Each
flute 23 has a leading edge 24 and a trailing edge 25 with respect
to the gas flowing through the flute arrangement. The vortex
generators (VGs) 27 are of a standard type (triangular prism with
one trailing edge) designed to generate two strong vortices, which
are expected to mix axially with the fuel injected by means of fuel
injectors 28.
[0004] The mixing of fuel with vortices is often delayed due to
slow interaction of vortices with the fuel jets. There are multiple
numbers of vortex generators 27 placed on the flutes 23 posing
difficulties in cooling and manufacturing. Furthermore, the current
design poses challenges in terms of uniform fuel distribution for
the nozzles.
[0005] Various other vortex generators and arrangements have been
proposed in the past.
[0006] U.S. Pat. No. 8,677,756 B2 discloses a burner, such as for a
secondary combustion chamber of a gas turbine with sequential
combustion having first and second combustion chambers, including
an injection device for introducing at least one gaseous fuel into
the burner. The injection device has at least one body which is
arranged in the burner with at least one nozzle for introducing the
gaseous fuel into the burner. The body is configured as a
streamlined body which has a streamlined cross-sectional profile
and which extends with a longitudinal direction perpendicularly or
at an inclination to a main flow direction prevailing in the
burner. The at least one nozzle has its outlet orifice at or in a
trailing edge of the streamlined body. The body has two lateral
surfaces substantially parallel to the main flow direction. At
least one vortex generator is located on at least one lateral
surface upstream of the at least one nozzle.
[0007] U.S. Pat. No. 8,402,768 B2 relates to a burner for a
combustion chamber of a gas turbine, with an injection device for
the introduction of at least one gaseous and/or liquid fuel into
the burner, wherein the injection device has at least one body
which is arranged in the burner with at least one nozzle for
introducing the at least one fuel into the burner, the at least one
body being configured as a streamlined body which has a streamlined
cross-sectional profile and which extends with a longitudinal
direction perpendicularly or at an inclination to a main flow
direction prevailing in the burner. The at least one nozzle has its
outlet orifice at or in a trailing edge of the streamlined body,
and with reference to a central plane of the streamlined body, the
trailing edge is provided with at least two lobes extending in
opposite transverse directions.
[0008] Document US 2012/285173 A1 discloses a swirler including an
annular housing with limiting walls. At least two vanes are
arranged in the annular housing including the sidewalls of the
swirler. The leading edge area of each vane has a profile, which is
oriented parallel to a main flow direction prevailing at the
leading edge position, wherein the profiles of the vanes turn from
the main flow direction prevailing at the leading edge position to
impose a swirl on the flow, and wherein, with reference to a
central plane of the vanes the trailing edges are provided with at
least two lobes in opposite transverse directions. A burner for a
combustion chamber of a gas turbine including such a swirler and at
least one nozzle having its outlet orifice at or in a trailing edge
of the vane and to a method of operation of such a burner.
[0009] Document US 2012/297787 A1 discloses a combined flow
straightener and mixer as well as a burner for a combustion chamber
of a gas turbine having such a mixing device. At least two
streamlined bodies are arranged in a structure comprising the side
walls of the mixer. The leading edge area of each streamlined body
has a profile, which is oriented parallel to a main flow direction
prevailing at the leading edge position, and with reference to a
central plane of the streamlined bodies, the trailing edges are
provided with at least two lobes in opposite transverse directions.
The periodic deflections forming the lobes from two adjacent
streamlined bodies are out of phase.
[0010] Document US 2014/109588 A1 relates to a burner for a
combustion chamber of a gas turbine with a mixing and injection
device. The mixing and injection device includes a limiting wall
that defines a gas-flow channel and at least two streamlined
bodies, each extending in a first transverse direction into the
gas-flow channel. Each streamlined body has two lateral surfaces
that are arranged essentially parallel to the main-flow direction,
the lateral surfaces being joined to one another at their upstream
side to form a leading edge of the body and joined at their
downstream side to form a trailing edge of the body. Each
streamlined body has a cross-section perpendicular to the first
transverse direction that is shaped as a streamlined profile. At
least one of the streamlined bodies is provided with a mixing
structure and with at least one fuel nozzle located at its trailing
edge for introducing at least one fuel essentially parallel to the
main-flow direction into the flow channel, wherein at least two of
the streamlined bodies have different lengths along the first
transverse direction such that they may be used for a can
combustor.
[0011] U.S. Pat. No. 8,490,398 B2 relates to a burner for a single
combustion chamber or first combustion chamber of a gas turbine,
with an injection device for the introduction of at least one
gaseous and/or liquid fuel into the burner, wherein the injection
device has at least one body which is arranged in the burner with
at least one nozzle for introducing the at least one fuel into the
burner. The at least one body is located in a first section of the
burner with a first cross-sectional area at a leading edge of the
at least one body with reference to a main flow direction
prevailing in the burner, wherein downstream of said body a mixing
zone is located with a second cross-sectional area, and at and/or
downstream of said body the cross-sectional area is reduced, such
that the first cross-sectional area is larger than the second
cross-sectional area.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide an
improved vortex generator and a fuel injection system equipped with
such vortex generators, which effect rapid mixing at allowable
pressure drops for higher firing temperature gas turbines.
[0013] It is another object of the invention to fuel-air mixing
within short burner-mixing length or time scales.
[0014] These and other objects are obtained by a vortex generator
according to Claim 1.
[0015] According to the invention, a vortex generator, especially
for a fuel injection system of a gas turbine, comprises a base area
and a vortex generator body extending in a tapering fashion from
said base area with a predetermined height.
[0016] It is characterized in that said vortex generator body forms
at least two partial vortex generators, whereby each of said at
least two partial vortex generators has its own trailing edge.
[0017] According to an embodiment of the invention said base area
has the form of a triangle.
[0018] According to another embodiment of the invention said at
least two partial vortex generators are arranged at different
heights with respect to said base area.
[0019] Said at least two partial vortex generators may be arranged
one above the other with respect to said base area, said upper
partial vortex generator having a first height and said lower
partial vortex generator having a second height.
[0020] According to another embodiment of the invention said at
least two partial vortex generators are arranged in a predetermined
angle to each other.
[0021] Said predetermined angle between said two partial vortex
generators may vary between 0.degree. to 45.degree..
[0022] According to another embodiment of the invention said at
least two partial vortex generators each have an associated attack
and sweep angle.
[0023] Said at least two partial vortex generators may be arranged
one above the other with respect to said base area, said upper
partial vortex generator having a first height and said lower
partial vortex generator having a second height, and said upper
partial vortex generator may have a higher attack and sweep angle
than said lower partial vortex generator.
[0024] According to another embodiment of the invention a fuel
injection means is provided between said at least two partial
vortex generators.
[0025] Said fuel injection means may be located with different
distances between said location and said at least two partial
vortex generators.
[0026] According to another embodiment of the invention said at
least two partial vortex generators have a leading edge, and the
leading edge of said at least two partial vortex generators has a
predetermined shape.
[0027] The fuel injection system of a gas turbine according to the
invention comprises at least one vortex generator, whereby said at
least one vortex generator is a vortex generator according to the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention is now to be explained more closely by
means of different embodiments and with reference to the attached
drawings.
[0029] FIG. 1 shows a current fuel injection system with current
vortex generators (VGs) mounted on vertical flutes;
[0030] FIG. 2 shows a standard vortex generator (VG);
[0031] FIG. 3 shows a so-called lobed vortex generator (VG)
according to an embodiment of the invention;
[0032] FIGS. 4A and 4B show in comparison a conceptual description
of a standard VG (FIG. 4A) and the new lobed VG design (FIG.
4B);
[0033] FIGS. 5A and 5B show in comparison the flow structures and
fuel distribution for the standard VG (FIG. 5A) and lobed VG design
(FIG. 5B);
[0034] FIGS. 6A and 6B show in comparison the velocity distribution
for the standard VG (FIG. 6A) and lobed VG designs (FIG. 6B);
[0035] FIGS. 7A and 7B show in comparison the flow structures and
fuel distribution for the standard VG (FIG. 7A) and lobed VG design
(FIG. 7B);
[0036] FIG. 8 shows the angle between the two (partial) VGs of the
lobed VG design, which can be allowed to vary between 0 to 45
degrees, and the height of the (two) VG trailing edges, which can
be varied so as to control hot gas mass flows; and
[0037] FIG. 9 shows another embodiment of the VG according to the
invention, wherein fuel can be injected between the (partial)
VGs.
DETAILED DESCRIPTION OF DIFFERENT EMBODIMENTS OF THE INVENTION
[0038] FIG. 2 shows a standard vortex generator (VG) 16, as it is
used in the fuel injection system 20 of FIG. 1. This vortex
generator 16 has a simple triangular base area 17 and a vortex
generator body 16a in form of a simple triangular prism with a
trailing edge 18 ending in an upper end 19.
[0039] A vortex generator according to an embodiment of the
invention is shown in comparison in FIG. 3. The vortex generator 10
of FIG. 3 involves splitting the standard vortex generator 16 of
FIG. 2 along a joining plane 15 into two partial vortex generators
VG1 and VG2 rotated by a certain angle (see the two arrows in FIG.
3). The size of this "lobed" VG design is much larger than the
standard designs thereby reducing the number of VGs mounted on the
flutes. In addition the number of fuel nozzles can be reduced in
relation to the number of VGs. The upper partial vortex generator
VG1 has a respective trailing edge 12a with a lower end 14 and an
upper end 13a. The lower partial vortex generator VG2 has a
respective trailing edge 12b starting at base area 11 and having an
upper end 13b.
[0040] FIGS. 4A and 4B show in comparison a conceptual description
of a standard VG (FIG. 4A) and the new lobed VG design (FIG. 4B).
The standard VG 16 has two strong vortices V1 and V2, which
traverse axially and mix with the fuel injected by fuel injector 26
at an appropriate axial location (FIG. 4A). The lobed VG 10
produces four smaller vortices V3-V6, which are circumferentially
traversing due to a vortex sheet VS emanating from the lobed flow
(FIG. 4B). With the lobed VG design there is a possibility to
produce a higher number of large scale and small scale vortices. In
addition the lobed VG design can reduce significantly the number of
mixing devices or vortex generators (VGs) required in a fuel
injector.
[0041] FIGS. 5A and 5B show in comparison (in a plane perpendicular
to the flow direction) the flow structures from the standard (FIG.
5A) and lobed VG design (FIG. 5B) at the exit of the respective VG.
The streamline plots show that the lobed VG design produces four
distinct vortices. The size of the vortices needs to be controlled
by optimizing the design features of the lobed-VG concept.
[0042] FIGS. 6A and 6B show in comparison the velocity distribution
for the standard VG (FIG. 6A) and lobed VG designs (FIG. 6B) in
form of the axial velocity vectors near the VG trailing edge. The
lobed VG's (FIG. 6B) with their leading edge 29 and their trailing
edges 12a and 12b (see also FIG. 7B) produce multiple small scale
vortices when compared to the two simple vortex structures produced
by the standard VGs (FIG. 6A). The locations of vortices are in
addition circumferentially spread for the lobed VG configuration.
The circumferential spread of the vortices helps in reaching the
fuel much faster.
[0043] FIGS. 7A and 7B show in comparison the flow structures and
fuel distribution for the standard VG (FIG. 7A) and lobed VG design
(FIG. 7B). The lobed VG design (FIG. 7B) produces a flow field
spread circumferentially resulting in improved mixing of the fuel
with hot gases.
[0044] FIG. 8 shows the angle between the two (partial) VGs VG1 and
VG2 of the lobed VG design, which can be allowed to vary between 0
to 45 degrees. The height h1 and h2 of the (two) VG trailing edges
12a and 12b can be varied so as to control hot gas mass flow. This
also ensures the vortex breakdown characteristics of the lobed
flow.
[0045] Finally, FIG. 9 shows another embodiment of the VG according
to the invention, wherein fuel can be injected by means of a fuel
injector 28 between the (partial) VGs.
[0046] In summary, a novel lobed vortex generator based fuel
injection system is proposed to introduce rapid mixing at allowable
pressure drops for higher firing temperature gas turbines. This
invention targets towards accomplishing fuel-air mixing within
short burner-mixing length or time scales. The concept includes
aerodynamically facilitated axial fuel injection with mixing
promoted by multiple vortices and lobed flow structures produced by
a new lobed-VG design. As a result, the burner is designed to
operate at increased hot gas temperature (2000K or more) or fuel
flexibility without suffering on high NOx emissions or flashback.
The proposed lobed-VG concept when compared to previous concepts is
simpler, lower cost with less number of complex VG structures. The
fuel distribution is much better for lobed-VG design due to reduced
number of nozzles.
[0047] The advantages of the new design are: [0048] Doubled number
of vortex structures for the lobed design when compared to standard
VG design which has only two vortex structures. [0049]
Circumferential spread of flow structures due to lobed flow
resulting in rapid mixing with fuel. [0050] The number of mixing
devices can be reduced with the lobed-VG design. This helps in
decreased cooling requirement for the flutes. The lobed-VG design
will require smaller number of VGs mounted on the flutes compared
to the standard VGs. For example, in the GT36-S6 gas turbine, there
are 32 VGs and 36 fuel nozzles used. With the lobed-VG design one
can reduce the number of VGs and fuel nozzles to at least 50%.
[0051] The size of the lobed VGs will be much larger than the
mini-VGs and also with less fuel nozzles, thus the fuel
distribution is improved. [0052] The production of multiple large
scale and small scale mixing structures from the lobed-VG design
can simplify the design. [0053] The cost of the lobed-VG should be
lower than the mini-VGs or lobes design because of a less VGs and
injectors. [0054] Design simplicity: The lobed-VG design will
eliminate the need for lobed fuel injectors. The design is simple
because one gets vortices and lobed flow by just orienting two
(partial) VGs at an angle. [0055] Less parts: Less number of mixing
devices and nozzles with the lobed-VG design when compared to the
standard mini-VG or lobed designs. [0056] Easy to manufacture by
Selective Laser Melting (SLM): The lobed VGs have larger sized VGs
and the lobe structures are produced by arranging the VGs at an
angle. There is no special manufacturing requirement for the
lobes.
[0057] The new vortex generator design may have different
embodiments: [0058] 1) The angle between the two partial VGs can be
allowed to vary between 0.degree. and 45.degree.. [0059] 2) The
height of the partial VG trailing edges can be varied so as to
control hot gas mass flows. This also ensures the vortex breakdown
characteristics of the lobed flow. [0060] 3) Fuel can be injected
between the partial VGs. With this option, one can eliminate the
need for central fuel nozzles. [0061] 4) The distance between the
fuel nozzle injection location and the partial VGs can be altered.
[0062] 5) The attack and sweep angles of the VG's can be modified
to reduce flow separation. The upper VG can be provided with high
attack and sweep angle and the lower VG can be with lower attack
and sweep angle. [0063] 6) The shape of the leading edge 29 of the
VG's can be modified (straight, elliptical, circular etc.) to alter
vortex characteristics.
LIST OF REFERENCE NUMERALS
[0063] [0064] 10 vortex generator [0065] 10a, 16a vortex generator
body [0066] 11,17 base area (triangular) [0067] 12a,b trailing edge
[0068] 13a,b upper end (trailing edge) [0069] 14 lower end
(trailing edge) [0070] 15 joining plane [0071] 16 vortex generator
(prior art) [0072] 18 trailing edge [0073] 19 upper end (trailing
edge) [0074] 20 fuel injection system (gas turbine) [0075] 21 lower
plate [0076] 22 upper plate [0077] 23 flute [0078] 24 leading edge
[0079] 25 trailing edge [0080] 26 fuel injector (nozzle) [0081] 27
vortex generator [0082] 28 fuel injector (nozzle) [0083] 29 leading
edge [0084] V1-V6 vortex [0085] VG1,VG2 vortex generator (partial)
[0086] VS vortex sheet
* * * * *