초록

Impingement hole patterns are provided in a combustor dome panel to provide efficient cooling of a combustor dome heat shield. The impingement holes are substantially aligned or located above partial height protuberances provided on the back face of the heat shield.

대표청구항 ▼

What is claimed is: 1. A combustor and dome heat shield assembly comprising a plurality of heat shield sectors mounted adjacent and spaced apart a distance from an annular dome of the combustor, each heat shield sector having a heat shield body defined between opposed lateral edges and radially inn

What is claimed is: 1. A combustor and dome heat shield assembly comprising a plurality of heat shield sectors mounted adjacent and spaced apart a distance from an annular dome of the combustor, each heat shield sector having a heat shield body defined between opposed lateral edges and radially inner and outer edges, at least one fuel nozzle opening defined in the heat shield body, the heat shield body having a back face facing the combustor dome, the back face having a first plurality of protuberances extending from the back face to a first height, the first height being substantially equal to said distance, the back face having a second plurality of protuberances extending from the back face to a second height, the second height being less than the first height, the combustor having a plurality of impingement cooling holes defined through the dome, the impingement cooling holes substantially aligned with the second plurality of protuberances, wherein a ratio of a diameter of the impingement cooling holes to a height between the impingement cooling holes and tops of the second plurality of protuberances is greater than one and less than five. 2. The combustor and dome heat shield assembly defined in claim 1, wherein the ratio is greater than one and less than three. 3. The combustor and dome heat shield assembly defined in claim 1, wherein the second height is substantially one half of the first height. 4. The combustor and dome heat shield assembly defined in claim 1, wherein the protuberances are frustoconical. 5. The combustor and dome heat shield assembly defined in claim 1, wherein the plurality of impingement cooling holes are defined in at least two rows, with at least one row disposed on each of opposed sides of the fuel nozzle opening, the rows defined on an arc concentric with a central axis of the combustor. 6. The combustor and dome heat shield assembly defined in claim 5, wherein the at least two rows comprises four rows, two on each side of the fuel nozzle opening. 7. The combustor and dome heat shield assembly defined in claim 1, wherein the heat shield body further comprises at least one ridge extending from the back face, and wherein the ridge extends along the back face adjacent at least a portion of said second plurality of protuberances. 8. The combustor and dome heat shield assembly defined in claim 7, wherein the plurality of impingement holes are defined in at least two non-intersecting rows, and wherein the at least one ridge extends along the back face between the at least two non-intersecting rows of impingement holes. 9. The combustor and dome heat shield assembly defined in claim 1, wherein the second plurality of protuberances are located adjacent to ridges extending from the back face of the heat shield body. 10. The combustor and dome heat shield assembly defined in claim 1, wherein said first plurality of protuberances are provided in at least one central region and in radially peripheral regions, and wherein concentration density of said first plurality of protuberances in said at least one central region is higher than in said radially peripheral regions. 11. The combustor and dome heat shield assembly defined in claim 10, wherein two central regions are provided, separated by at least one laterally extending ridge, and wherein said radially peripheral regions comprise an inner peripheral region radially inwardly of the at least one laterally extending ridge and an outer peripheral region radially outwardly of the at least one laterally extending ridge. 12. The combustor and dome heat shield assembly defined in claim 1, wherein the back face is divided in regions by ridges projecting along said back face, said regions including radially inner corner regions and radially outer corner regions, and wherein said radially inner and radially outer corner regions are each provided with at least one row of the second plurality of protuberances adjacent the ridges separating the radially outer corners from the radially inner corners. 13. The combustor and dome heat shield assembly defined in claim 1, wherein ridges extend along the back face of the heat shield body, said ridges cooperating to direct a flow of cooling air to said radially outer and inner edges where the cooling air is discharged from the back face of the heat shield body, and wherein and array of straightener ribs is provided along at least one of said radially inner and radially outer edges. 14. The combustor dome and heat shield assembly defined in claim 1, wherein a central circular ridge extends around the at least one fuel nozzle opening on the back face of the heat shield body, said central circular ridge circumscribing a central area, and wherein a plurality of cooling holes are defined through the heat shield body in said central area. 15. The combustor and dome heat shield assembly defined in claim 14, further comprising diametrically opposed ridges running from said central circular ridge towards said opposed lateral edges, a first pair of ridges running from the central circular ridge towards the radially outer edge in a direction generally perpendicular thereto, and a second pair of ridges running from the central circular ridge towards the radially inner edge in a direction generally perpendicular thereto. 16. The combustor and dome heat shields assembly defined in claim 14, further comprising diametrically opposed ridges running from said central circular ridge towards said opposed lateral edges, and wherein the heat exchange promoting structures are arranged in rows substantially parallel to said diametrically opposed ridges. 17. The combustor and dome heat shield assembly defined in claim 1, wherein the impingement holes are arranged on circular arrays. 18. A combustor dome comprising at least one heat shield mounted to an annular dome panel, the at least one heat shield and the dome panel defining an air space therebetween and at least one fuel nozzle opening for receiving a fuel nozzle, a plurality of impingement holes defined in said dome panel for causing an impingement fluid to impinge upon a back face of the at least one heat shield, the back face having a heat exchange promoting protuberance pattern thereon, said pattern being divided in regions by ribs projecting outwardly from said back face, said ribs including a first rib extending around said fuel nozzle opening and circumscribing a central annular area and a second rib extending from opposed sides of the first rib towards lateral edges of the at least one heat shield, the heat exchange promoting protuberance pattern including first and second set of protuberances, the protuberances of the second set being shorter than the protuberances of the first set and located at least partly outwardly of the central annular area adjacent to the first rib and adjacent to the second rib on either sides thereof, wherein the impingement holes are substantially aligned with the second set of protuberances, and wherein a ratio of a diameter of the impingement holes to a height between the impingement holes and tops of the second set of protuberances is greater than one and less than five. 19. The combustor dome defined in claim 18, wherein said plurality of impingement holes comprises a first set of holes arranged in at least one circular array around the fuel nozzle opening within the first rib for causing a cooling fluid to impinge upon said central annular area, and a second set of holes circumferentially distributed about a central axis of the annular dome panel, said second set of holes being disposed outside of said at least one circular array for directing the cooling fluid upon the regions of the back face of the heat shield located outside of said first rib. 20. The combustor dome defined in claim 18, wherein the ratio is greater than one and less than three. 21. The combustor dome defined in claim 18, wherein the height of the protuberances of the second set is substantially one half of the height of the protuberances of the first set. 22. The combustor dome defined in claim 18, wherein the plurality of impingement holes are defined in at least two rows, with at least one row disposed on each of opposed sides of the fuel nozzle opening, the rows defined on an arc concentric with a central axis of the combustor dome. 23. The combustor and dome heat shield assembly defined in claim 18, wherein said first set of protuberances are provided in at least one central region and in radially peripheral regions, and wherein concentration density of said first set of protuberances in said at least one central region is higher than in said radially peripheral regions. 24. A combustor and dome heat shield assembly comprising a plurality of heat shield sectors mounted adjacent and spaced apart a distance from an annular dome of the combustor, each heat shield sector having a heat shield body defined between opposed lateral edges and radially inner and outer edges, at least one fuel nozzle opening defined in the heat shield body, the heat shield body having a back face facing the combustor dome, the back face having a first plurality of protuberances extending from the back face to a first height, the first height being substantially equal to said distance, the back face having a second plurality of protuberances extending from the back face to a second height, the second height being less than the first height, the combustor having a plurality of impingement cooling holes defined through the dome, the impingement cooling holes substantially aligned with the second plurality of protuberances, wherein the protuberances are frustoconical. 25. The combustor and dome heat shield assembly defined in claim 24, wherein the heat shield body has a central circular ridge extending around the at least one fuel nozzle opening, and wherein said heat shield body is free from cooling holes outside of the area circumscribed by the central circular ridge. 26. A combustor and dome heat shield assembly comprising a plurality of heat shield sectors mounted adjacent and spaced apart a distance from an annular dome of the combustor, each heat shield sector having a heat shield body defined between opposed lateral edges and radially inner and outer edges, at least one fuel nozzle opening defined in the heat shield body, the heat shield body having a back face facing the combustor dome, the back face having a first plurality of protuberances extending from the back face to a first height, the first height being substantially equal to said distance, the back face, having a second plurality of protuberances extending from the back face to a second height, the second height being less than the first height, the combustor having a plurality of impingement cooling holes defined through the dome, the impingement cooling holes substantially aligned with the second plurality of protuberances, wherein said first plurality of protuberances are provided in at least one central region and in radially peripheral regions, and wherein concentration density of said first plurality of protuberances in said at least one central region is higher than in said radially peripheral regions. 27. A combustor and dome heat shield assembly comprising a plurality of heat shield sectors mounted adjacent and spaced apart a distance from an annular dome of the combustor, each heat shield sector having a heat shield body defined between opposed lateral edges and radially inner and outer edges, at least one fuel nozzle opening defined in the heat shield body, the heat shield body having a back face facing the combustor dome, the back face having a first plurality of protuberances extending from the back face to a first height, the first height being substantially equal to said distance, the back face having a second plurality of protuberances extending from the back face to a second height, the second height being less than the first height, the combustor having a plurality of impingement cooling holes defined through the dome, the impingement cooling holes substantially aligned with the second plurality of protuberances, wherein ridges extend along the back face of the heat shield body, said ridges cooperating to direct a flow of cooling air to said radially outer and inner edges where the cooling air is discharged from the back face of the heat shield body, and wherein and array of straightener ribs is provided along at least one of said radially inner and radially outer edges. 28. A combustor and dome heat shield assembly comprising a plurality of heat shield sectors mounted adjacent and spaced apart a distance from an annular dome of the combustor, each heat shield sector having a heat shield body defined between opposed lateral edges and radially inner and outer edges, at least one fuel nozzle opening defined in the heat shield body, the heat shield body having a back face facing the combustor dome, the back face having a first plurality of protuberances extending from the back face to a first height, the first height being substantially equal to said distance, the back face having a second plurality of protuberances extending from the back face to a second height, the second height being less than the first height, the combustor having a plurality of impingement cooling holes defined through the dome, the impingement cooling holes substantially aligned with the second plurality of protuberances, wherein a central circular ridge extends around the at least one fuel nozzle opening on the back face of the heat shield body, said central circular ridge circumscribing a central area, and wherein a plurality of cooling holes are defined through the heat shield body in said central area, further comprising diametrically opposed ridges running from said central circular ridge towards said opposed lateral edges, a first pair of ridges running from the central circular ridge towards the radially outer edge in a direction generally perpendicular thereto, and a second pair of ridges running from the central circular ridge towards the radially inner edge in a direction generally perpendicular thereto. 29. A combustor and dome heat shield assembly comprising a plurality of heat shield sectors mounted adjacent and spaced apart a distance from an annular dome of the combustor, each heat shield sector having a heat shield body defined between opposed lateral edges and radially inner and outer edges, at least one fuel nozzle opening defined in the heat shield body, the heat shield body having a back face facing the combustor dome, the back face having a first plurality of protuberances extending from the back face to a first height, the first height being substantially equal to said distance, the back face having a second plurality of protuberances extending from the back face to a second height, the second height being less than the first height, the combustor having a plurality of impingement cooling holes defined through the dome, the impingement cooling holes substantially aligned with the second plurality of protuberances, wherein a central circular ridge extends around the at least one fuel nozzle opening on the back face of the heat shield body, said central circular ridge circumscribing a central area, and wherein a plurality of cooling holes are defined through the heat shield body in said central area, further comprising diametrically opposed ridges running from said central circular ridge towards said opposed lateral edges, and wherein the heat exchange promoting structures are arranged in rows substantially parallel to said diametrically opposed ridges.