Combustor Cooled Quench Zone Array
In accordance with one aspect of the disclosure, a combustor is disclosed. The combustor may include a shell and a liner disposed within the shell. The combustor may further include a grommet at least partially defining a hole communicating through the shell and liner and a cooling channel communicating through the grommet.
Latest United Technologies Corporation Patents:
This patent application is a US National Stage under 35 U.S.C. §371, claiming priority to International Application No. PCT/US13/021718 filed on Jan. 16, 2013.
FIELD OF THE DISCLOSUREThe present disclosure generally relates to gas turbine engines and, more specifically, to cooling of combustors in gas turbine engines.
BACKGROUND OF THE DISCLOSUREA gas turbine engine, typically used as a source of propulsion in aircraft, operates by drawing in ambient air, combusting that air with a fuel, and then forcing the exhaust from the combustion process out of the engine. A fan on a forward end of the engine rotates to draw in ambient air. The air is then compressed by a compressor section having a low-pressure and high-pressure compressor. A portion of the compressed air is used to cool the combustor, while the rest is mixed with a fuel and ignited.
Typically, an igniter generates an electrical spark to ignite the air-fuel mixture. The products of the combustion, water, CO2, NOx, and CO, then travel out of the combustor and exhaust through a turbine. The turbine section, also having a low-pressure and high-pressure turbine, is forced to rotate as the exhaust exits the engine. The turbine section and the compressor section are connected by two concentrically mounted rotating shafts running through the center of the engine. One shaft connects the low-pressure compressor and turbine, while the other shaft connects the high-pressure compressor and turbine. Thus, as the turbine section rotates from the exhaust, the compressor section rotates to bring in and compress new air. Once started, it can therefore be seen that this process is self-sustaining.
Combustors for gas turbine engines typically have an outer combustor shell and an outer liner, which may be made of a plurality of panels, disposed radially inside the outer combustor shell. Additionally, annular combustors have an inner shell and an inner liner radially outside of the inner shell. The inner and outer liners are separated by and define an annular combustion chamber. Flow cavities are typically provided between each pair of shells and liners. Cooling air is forced through these flow cavities and into the combustion chamber, creating a cooling film on hot surfaces of the liners.
The remaining portion of the compressed air is used as dilution air to fully burn all of the fuel in the combustion chamber and reduce the temperature of the exhaust. This dilution air is typically injected into a rear section of the combustion chamber through a plurality of holes defined by a plurality of grommets. In prior art designs, engines did not provide any extra cooling for such grommets, and indeed until recent improvements in the design of combustors, extra cooling was often not needed. However, as combustors have advanced, to increase engine power, the temperatures in the combustion chambers have increased. Advanced cooling for the combustor, including for the grommets, is therefore needed. If these areas are not adequately cooled, spallation of the liner, loss of combustor liner material, and cracks or other heat stress related fatigue may occur.
SUMMARY OF THE DISCLOSUREIn accordance with one aspect of the disclosure, a combustor is disclosed. The combustor may include a shell and a grommet at least partially defining a hole communicating through at least the shell, and a cooling channel communicating through the grommet.
In a refinement, the cooling channel may be oriented perpendicular to a radially inward surface of the grommet with respect to an axis of the combustor extending longitudinally through the combustor.
In another refinement, the cooling channel may be provided at a non-perpendicular angle to the radially inward surface of the grommet.
In a further refinement, the cooling channel may communicate through the grommet from a surrounding surface of the grommet oriented perpendicular to the shell of the combustor and facing away from the hole defined y the grommet to the radially inward surface of the grommet.
In another further refinement, the shell may be engaged with a radially outward surface of the grommet with respect to the axis of the combustor.
In another refinement, between six to sixteen cooling channels may communicate through the grommet.
In yet another refinement, each cooling channel may be separated by a distance about equal to three to ten times the diameter of the cooling channels.
In yet another refinement, the grommet may have a second outward surface with respect to the axis of the combustor engaged with the shell of the combustor.
In still another refinement, the grommet may be unitary with the shell and may define a hole communicating through the shell.
In still yet another refinement, the grommet may be separate from the shell and a liner of the combustor, the liner being positioned radially inside the shell with respect to the axis of the combustor, and the grommet being positioned between the shell and liner.
In accordance with another embodiment, a liner of a combustor is disclosed. The liner may include a liner panel having a hot surface and a grommet defining a hole communicating through the liner panel. The liner may further include a cooling channel communicating through the grommet.
In a refinement, the grommet may have a radially inward surface and a radially outward surface with respect to an axis extending longitudinally through the combustor, and the cooling channel may extend from the radially outward surface of the grommet to the radially inward surface of the grommet.
In another refinement, the cooling channel may be at a non-perpendicular angle to the radially inward surface of the grommet.
In a further refinement, the cooling channel may communicate through the grommet from a surrounding surface of the grommet perpendicular to the radially outward surface of the grommet and facing away from the hole defined by the grommet to the radially inward surface of the grommet.
In another refinement, between six to sixteen cooling channels may communicate through the grommet.
In yet another refinement, each cooling channel may be separated by a distance about equal to three to ten times the diameter of the cooling channels.
In yet another refinement, the grommet may be unitary with the liner panel and the radially inward surface of the grommet is the same surface as the hot surface f the liner panel.
In still yet another refinement, the grommet may be a dilution hole grommet and may define a dilution hole.
In accordance with yet another embodiment, a method of cooling a liner of a combustor is disclosed. The method may include providing a grommet with the liner of the combustor, which may at least partially define a hole through the liner panel. The method may further include directing cooling air through a cooling channel communicating through the grommet and cooling the grommet with the cooling air flowing through the cooling channel by transferring heat from the grommet to the cooling air.
In a refinement, the method may further include blowing a flame in the combustor off the inward surface of the grommet with the cooling air flowing through the cooling channel.
These and other aspects and features of the present disclosure will be better understood in light of the following detailed description when read in light of the accompanying drawings.
It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of this disclosure or which render other details difficult to perceive may have been omitted. It should be understood, of course, that this disclosure is not limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTIONReferring now to the drawings, and with specific reference to
The combustor 118 has a shell 132 and may include a liner 130 mounted to the shell 132. In the annular combustor illustrated in
The compressed air 114 not entering through the swirlers 124 as combustion air 122 may be used as cooling air 144 and dilution air 146. The cooling air 144 flows through a plurality of impingement holes 172 communicating through the shell 132 into the flow cavity 170 and through a plurality of effusion holes 174 communicating through the liner 130 into the combustion chamber 135. The dilution air 146, on the other hand, may enter the combustion chamber 135 at a rear section 148 through at least one dilution hole 150 communicating through the liner 130 and shell 132. In some embodiments at least one dilution hole 150 communicates through the liner 130 and shell 132 in a forward section 152 of the combustion chamber 135. The dilution air 146 is burnt in the combustion chamber 135 to complete the combustion process. Additionally, the dilution air 146 may reduce the temperature of the exhaust 136 before the exhaust 136 reaches the turbine section 138.
In one embodiment, as illustrated in
Speaking now to the embodiment illustrated in
Turning now to embodiments where the grommet 156 is unitary with the liner 130, such as illustrated in FIGS. 3 and 6-8. The cooling channels 160 communicate through the grommet 156, or in these embodiments the raised platform that will herein after be referred to simply as the grommet 156, to the hot surface 162 of the liner 130. For all purposes herein, the inward surface 159 of a grommet 156 which is separate from the liner 130 is equivalent to the hot surface 162 of the liner 130 when the grommet 156 is unitary with the liner 130.
While ten cooling channels 160 are shown in each grommet 156 in
In some embodiments, the grommet 156 may have a second radially outward surface 166 with respect to the combustor axis 119, which is engaged to an interior surface 167 of the shell 132 still with respect to the combustor axis 119, as seen in
As illustrated in
In another embodiment, as can be seen in
In combustors 118 which have no liner 130 but only a shell 132, such as in a can combustor or a single wall annular combustor as illustrated in
The cooling air 144 flowing through the cooling channels 160 described above and illustrated in
From the foregoing, it can be seen that the technology disclosed herein has industrial applicability in a variety of settings such as, but not limited to, cooling dilution hole grommets and the liner around dilution holes (or other holes) in combustors of gas turbine engines. Such engines may be used, for example, in aircraft to generate thrust or in land-based applications to generate power. This improvement over prior art reduces the temperature of the combustor liner around the dilution holes. The reduction in temperature makes the liner less susceptible to damage by heat during engine operations. Such damage may include spallation of the combustor liner, loss of combustor liner material, and cracks or other heat stress related fatigue in the combustor liner.
While the present disclosure has been in reference to dilution hole grommets, a gas turbine engine, and an aircraft, one skilled in the art will understand that the teachings herein can be used in other applications as well such as, but not limited to, with igniter hole grommets. It is therefore intended that the scope of the invention not be limited by the embodiments presented herein as the best mode for carrying out the invention, but that the invention will include all embodiments falling within the scope of the claims.
Claims
1. A combustor, comprising:
- a shell;
- a grommet at least partially defining a hole communicating through at least the shell; and
- a cooling channel communicating through the grommet.
2. The combustor of claim 1, wherein the cooling channel is oriented perpendicular to a radially inward surface of the grommet with respect to an axis extending longitudinally through the combustor.
3. The combustor of claim 1, wherein the cooling channel is provided at a non-perpendicular angle to the radially inward surface of the grommet.
4. The combustor of claim 3, wherein the cooling channel communicates through the grommet from a surrounding surface of the grommet oriented perpendicular to the shell of the combustor and facing away from the hole defined by the grommet to the radially inward surface of the grommet.
5. The combustor of claim 4, wherein the shell is engaged with a radially outward surface of the grommet with respect to the axis of the combustor.
6. The combustor of claim 1, wherein between six to sixteen cooling channels communicate through the grommet.
7. The combustor of claim 1, wherein each cooling channel is separated by a distance about equal to three to ten times the diameter of the cooling channels.
8. The combustor of claim 1, wherein the grommet has a second radially outward surface with respect to the axis of the combustor engaged with the shell of the combustor.
9. The combustor of claim 1, wherein the grommet is unitary with the shell and defines a hole communicating through the shell.
10. The combustor of claim 1, wherein the grommet is separate from the shell and a liner of the combustor, the liner being positioned radially inside the shell with respect to the axis of the combustor, and the grommet being positioned between the shell and liner.
11. A liner of a combustor, comprising:
- a liner panel having a hot surface;
- a grommet defining a hole communicating through the liner panel; and
- a cooling channel communicating through the grommet.
12. The liner of claim 11, wherein the grommet has a radially inward surface and a radially outward surface with respect to an axis extending longitudinally through the combustor, and the cooling channel extends from the radially outward surface of the grommet to the radially inward surface of the grommet.
13. The liner of claim 11, wherein the cooling channel is at a non-perpendicular angle to the radially inward surface of the grommet.
14. The liner of claim 13, wherein the cooling channel communicates through the grommet from a surrounding surface of the grommet perpendicular to the radially outward surface of the grommet and facing away from the hole defined by the grommet to the radially inward surface of the grommet.
15. The liner of claim 11, wherein between six to sixteen cooling channels communicate through the grommet.
16. The liner of claim 11, wherein each cooling channel is separated by a distance about equal to three to ten times the diameter of the cooling channels.
17. The liner of claim 11, wherein the grommet is unitary with the liner panel and the radially inward surface of the grommet is the same surface as the hot surface of the liner panel.
18. The liner of claim 11, wherein the grommet is a dilution hole grommet and defines a dilution hole.
19. A method of cooling a liner of a combustor, comprising:
- providing a grommet with the liner of the combustor, the grommet at least partially defining a hole through the liner panel;
- directing cooling air through a cooling channel communicating through the grommet; and
- cooling the grommet with the cooling air flowing through the cooling channel by transferring heat from the grommet to the cooling air.
20. The method of claim 19, further comprising blowing a flame in the combustor off the inward surface of the grommet with the cooling air flowing through the cooling channel.
Type: Application
Filed: Jan 16, 2013
Publication Date: Dec 10, 2015
Applicant: United Technologies Corporation (Hartford, CT)
Inventors: Timothy S. Snyder (Glastonbury, CT), James B. Hoke (Tolland, CT)
Application Number: 14/759,811