Insulation tile and thermal shield for a gas turbine combustor

Abstract

The present application provides a heat insulation tile and a heat shield for a gas turbine combustor. The heat insulation tile includes a closed cavity, a lower bottom plate and an upper cover plate. The closed cavity is arranged inside the heat insulation tile; a cooling air inlet is provided on the lower bottom plate, and cooling air enters the closed cavity from the cooling air inlet. The upper cover plate is integrally formed with the lower bottom plate, and the outer side of the upper cover plate is in contact with hot gas; a plurality of cooling air channels are evenly distributed on the upper cover plate, one end of the cooling air channel is communicated with the closed cavity, the other end of the cooling air channel is communicated with the combustor, and a first air outlet hole is provided; the cooling air channel is inclined. The present application adopts a combined form of film cooling and impingement cooling to perform heat insulation cooling on the combustor cylinder body, thereby avoiding direct impact of hot gas and effectively improving the heat resistance of the heat insulation tile. The present application improves the heat insulation performance and cooling efficiency, ensures the cooling effect, overcomes the problems of fragmentation of existing ceramic tiles and ablation of metal tiles, enhances the service life of the heat insulation tile, and ensures the safe operation of the gas turbine.

Description

Technical Field

[0001] This application relates to the technical field of gas turbines, and more particularly, to a heat insulation tile and a heat shield for a gas turbine combustion chamber. Background Art

[0002] In an industrial heavy-duty F-class gas turbine annular combustion chamber, the temperature of the hot gas is extremely high, and the local temperature can reach up to 1700K. Conventional heat-resistant alloys cannot withstand such high temperatures, so corresponding heat insulation structures are designed in the combustion chamber. For the ground heavy-duty gas turbine annular combustion chamber system, ceramic materials and metal tiles are usually used for heat insulation.

[0003] As a peak shaving unit, the heavy-duty gas turbine frequently starts, stops, and changes load, and the temperature difference on the hot side in the combustion chamber changes violently. Especially with the market's demand for higher parameters, higher efficiency, and lower emissions for gas turbines, it poses a great threat to the service life and reliability of ceramic heat insulation tiles. Cracks are likely to occur suddenly in the ceramic heat insulation tiles under thermal stress, resulting in a tripping accident. The existing metal heat insulation tiles have no efficient cooling structure, and the heat-resistant coating on the surface is prone to peeling, leading to ablation and melting of the metal substrate.

[0004] In summary, an improved technical solution is needed to address the deficiencies of the above-mentioned existing technologies. Summary of the Invention

[0005] The purpose of the embodiments of this application is to provide a heat insulation tile and a heat shield for a gas turbine combustion chamber, which can greatly improve the cooling efficiency, enhance the service life of the heat insulation tile, and overall improve the reliability of the gas turbine without increasing the cold air.

[0006] In a first aspect, a heat insulation tile for a gas turbine combustion chamber is provided, including: a closed cavity, a lower bottom plate, and an upper cover plate.

[0007] The heat insulation tile is a curved block with a predetermined thickness, and the closed cavity is provided inside the heat insulation tile; the lower bottom plate is provided on the side where the heat insulation tile contacts the combustion chamber cylinder block, and a cooling air inlet is provided on the lower bottom plate. The cooling air enters the closed cavity from the cooling air inlet; after the cooling gas enters the closed cavity, it decelerates and expands, making the distribution of the cooling gas in the closed space more uniform and ensuring the cooling effect of the cooling gas. The upper cover plate is integrally formed with the lower bottom plate, and the outer side of the upper cover plate contacts the hot gas; a plurality of cooling air channels are evenly distributed on the upper cover plate. One end of the cooling air channel is connected to the closed cavity, which is the air inlet end; the other end of the cooling air channel is connected to the combustion chamber, which is the air outlet end; a first air outlet hole is provided at the air outlet end of the cooling air channel; the cooling air channel is inclined, and the cooling gas is obliquely ejected through the first air outlet hole and forms a layer of cooling air film in cooperation with the hot gas flow on the outer surface of the upper cover plate.

[0008] In one embodiment, the peripheral side of the upper cover plate is bent towards the lower bottom plate to form a side edge, the side edge is integrally connected to the lower bottom plate, and a plurality of second air outlet holes are provided on the side edge, and the second air outlet holes are used to introduce cooling gas into the circumferential and axial gaps of the heat insulation tile.

[0009] In one embodiment, the cooling air duct sequentially includes a cylindrical channel and a gradually expanding channel along the air outlet direction.

[0010] In one embodiment, the slopes of the axial centerlines of the cylindrical channel and the gradually expanding channel are the same.

[0011] In one embodiment, the gradually expanding channel is wedge-shaped, and the diameter of the gradually expanding channel increases sequentially along the length direction of the cooling air duct.

[0012] In one embodiment, the first air outlet holes include a plurality of uniformly distributed first air outlet holes.

[0013] In one embodiment, the cross-section of the first air outlet hole is trapezoidal, square, circular or elliptical.

[0014] In one embodiment, the plurality of second air outlet holes on the side edge are uniformly arranged.

[0015] In one embodiment, the second air outlet hole is bent along its length direction.

[0016] According to the second aspect of the present application, there is also provided a heat shield for a gas turbine combustor, including multiple circles of heat insulation tiles, the multiple circles of heat insulation tiles are arranged axially along the combustor, and the heat insulation tiles are the heat insulation tiles of the gas turbine combustor provided in the first aspect.

[0017] Compared with the prior art, the beneficial effects of the present application are:

[0018] In the technical solution of this application, the heat insulation tile is a metal heat insulation tile, which replaces the technology of using ceramic chips for heat insulation in the existing heat insulation tiles. It is formed by 3D printing or precision casting to ensure the structural stability. Through the setting of the closed cavity, before the cooling gas is sprayed into the combustion chamber, it first decelerates and expands in the closed cavity to ensure the uniformity of the cooling gas. For the existing sheet heat insulation tiles, only the impingement cooling form is used to cool the hot-side upper cover plate, and the cooling gas will disperse through the gap between the sheet heat insulation tile and the combustion chamber cylinder block. While this application adopts a combined form of film cooling and impingement cooling. Through the setting of the sealed cavity, after the decelerated and expanded cooling gas is obliquely ejected through the upper cover plate cooling air duct, a cooling gas film is formed by the common action of the cooling gas and the hot gas flow on the outer surface of the upper cover plate. The four side edges use impingement cooling to cool the gap. The closed heat insulation tile structure prevents the cooling gas from dispersing and improves the utilization rate of the cooling gas. This application can, without increasing the cooling air, perform heat insulation and cooling on the heat insulation tile through the cooling gas film, thereby avoiding the direct impact of the hot gas, effectively improving the heat resistance of the heat insulation tile. This application improves the heat insulation performance and cooling efficiency, ensures the cooling effect, overcomes the problems of fragmentation of the existing ceramic tiles and ablation of the metal tiles, enhances the service life of the heat insulation tile, and ensures the safe operation of the gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a three-dimensional structural schematic diagram of the heat insulation tile of the gas turbine combustion chamber according to an embodiment of the present invention.

[0020] Figure 2 is a longitudinal sectional view of the heat insulation tile of the gas turbine combustion chamber according to an embodiment of the present invention;

[0021] Figure 3 is a detailed structural diagram of the cooling air duct in the heat insulation tile of the gas turbine combustion chamber according to an embodiment of the present invention.

[0022] Among them, the description of the reference numerals is as follows:

[0023] 1. Combustion chamber cylinder block; 2. Upper cover plate; 3. Lower bottom plate; 4. Side edge; 5. Closed cavity; 6. Cooling air duct; 61. Cylindrical channel; 62. Diverging channel; 7. First air outlet hole; 8. Second air outlet hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following further describes in detail the specific embodiments of the present invention with reference to the drawings. These embodiments are only used to illustrate the present invention and are not intended to limit the present invention.

[0025] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In addition, in the description of the present invention, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0028] According to the first aspect of the present application, referring to Figure 1 and Figure 2 , first, a heat insulation tile for a gas turbine combustor is provided, including: a closed cavity 5, a lower bottom plate 3, and an upper cover plate 2.

[0029] The heat insulation tile is a curved block with a predetermined thickness, and the closed cavity 5 is arranged inside the heat insulation tile; the lower bottom plate 3 is arranged on the side where the heat insulation tile contacts the combustor cylinder block 1, and a cooling air inlet is provided on the lower bottom plate 3, and the cooling air enters the closed cavity 5 from the cooling air inlet; Figure 2 The arrow direction in

[0030] The heat-insulating tile of the present application is a metal heat-insulating tile, which replaces the technology of using ceramic sheets for heat insulation in the existing heat-insulating tile. It adopts 3D printing or precision casting to ensure the stability of the structure. Through the setting of the closed cavity 5, the cooling gas is decelerated and expanded in the closed cavity 5 before being sprayed into the combustion chamber to ensure the uniformity of the cooling gas. The existing sheet-like heat-insulating tile only uses the form of impact cooling to cool the upper cover plate on the hot side, and the cooling gas will be scattered through the gap between the sheet-like heat-insulating tile and the cylinder body of the combustion chamber. However, the present application adopts a combination of air film cooling and impact cooling. Through the setting of the closed cavity 5, the cooling gas after deceleration and expansion is obliquely ejected through the cooling air duct 6 of the upper cover plate 2, and then a layer of cooling air film is formed on the outer surface of the upper cover plate 2 together with the hot gas flow. The surrounding sides 4 use impact cooling to cool the gap. The closed heat-insulating tile structure prevents the cooling gas from scattering, thereby improving the utilization rate of the cooling gas. The present application can insulate and cool the thermal insulation tiles through the cooling air film while ensuring that the cold air does not increase, thereby avoiding the direct impact of hot gas and effectively improving the heat resistance of the thermal insulation tiles. The present application improves the thermal insulation performance and cooling efficiency, ensures the cooling effect, overcomes the existing problems of ceramic tile fragmentation and metal tile ablation, increases the life of the thermal insulation tiles, and ensures the safe operation of the gas turbine.

[0031] In one embodiment, the circumferential side of the upper cover plate 2 is bent toward one side of the lower bottom plate 3 to form a side edge 4, which is integrally connected to the lower bottom plate 3. A plurality of second air outlet holes 8 are provided on the side edge 4, and the second air outlet holes 8 are used to pass cooling gas into the circumferential and axial gaps of the thermal insulation tile. By providing the second air outlet holes 8, impact cooling is achieved for the circumferential and axial gaps of the thermal insulation tile, further ensuring the cooling efficiency and the safety of the combustion chamber cylinder 1.

[0032] In one embodiment, Figure 3 As shown, the cooling air channel 6 includes a cylindrical channel 61 and a gradually diverging channel 62 in sequence along the outlet direction. The cylindrical channel 61 guides the cooling gas. The cooling gas first flows along the cylindrical channel 61 and then is discharged through the gradually diverging channel 62.

[0033] In one embodiment, the axial center lines of the cylindrical channel 61 and the gradually diverging channel 62 have the same slope, ensuring that the cooling gas is obliquely ejected at a predetermined angle.

[0034] In one embodiment, the gradually expanding channel 62 is wedge-shaped, and the diameter of the gradually expanding channel 62 increases successively along the length direction of the cooling air channel 6. By setting the gradually expanding channel 62, the cross-sectional radius through which the cooling gas passes is increased, and the impact force of the cooling gas is slowly reduced, preventing the impact pressure of the cooling gas from being too high and directly rushing into the combustion chamber. A layer of cooling air film is formed on the surface of the thermal insulation tile provided by the present application under the action of the hot air flow and the jet of the cooling hole.

[0035] In one embodiment, the first air outlet holes 7 include multiple rows of first air outlet holes 7, and adjacent two rows of first air outlet holes 7 are arranged staggeredly, so that the cooling air film on the surface of the heat insulation tile is more uniform.

[0036] It should be noted that the arrangement manner of the first air outlet holes 7 in this application is not limited to the above content, and adjacent two rows of first air outlet holes 7 can also be correspondingly arranged. The purpose is to evenly arrange multiple first air outlet holes 7 on the upper cover plate 2, so that the ejected cooling gas is more uniform and the cooling air film on the surface of the heat insulation tile is more uniform.

[0037] In one embodiment, the cross-section of the first air outlet holes 7 is trapezoidal.

[0038] It should be noted that the cooling air duct 6 inclines towards the lower bottom side of the trapezoid. After the cooling air duct 6 ejects through each trapezoidal first air outlet hole 7, the area of the single air column in contact with the upper cover plate 2 is larger, which is beneficial to the attachment of the cooling air column to the outer surface of the upper cover plate 2. In this application, the shape of the cross-section of the first air outlet holes 7 is not limited to trapezoidal, and can also be set as square, circular or oval.

[0039] In one embodiment, multiple second air outlet holes 8 are evenly arranged to prevent uneven distribution of the cooling gas between adjacent heat insulation tiles, and can effectively resist the hot gas, preventing ablation of the corners of the heat insulation tile and the combustion chamber cylinder block 1.

[0040] In one embodiment, the second air outlet holes 8 are bent along their length direction. By increasing the length of the air outlet path, the cooling effect on the heat insulation tile body is enhanced, and at the same time, the circumferential and axial gaps of the heat insulation tile can also be subjected to impingement cooling. The arrangement manner of the second air outlet holes 8 in this application is not limited to the above setting, and the second air outlet holes 8 can also be set as straight holes or special-shaped holes along their length direction. It should be noted that the second air outlet holes 8 can include multiple rows of second air outlet holes 8, and adjacent two rows of second air outlet holes 8 are arranged staggeredly to more evenly perform impingement cooling on the axial and axial gaps of the heat insulation tile. The arrangement manner of the second air outlet holes 8 in this application is not limited to the above content, and adjacent two rows of second air outlet holes 8 can also be correspondingly arranged. Therefore, by evenly arranging multiple second air outlet holes 8 on the side 4 of the heat insulation tile, more uniform impingement cooling can be performed on the axial and axial gaps of the heat insulation tile.

[0041] According to the second aspect of the present application, a heat shield for a gas turbine combustion chamber is further provided, including multiple circles of heat insulation tiles provided as in the first aspect arranged along the axial direction of the combustion chamber.

[0042] The traditional metal heat insulation tile structure is a simple single-layer cover plate structure, which only cools the bottom surface of the cover plate. There is no efficient cooling structure on the side where the cover plate contacts the combustion gas. Once the heat-resistant coating (ceramic) on the surface peels off, it will cause the ablation and melting of the metal substrate. Therefore, it cannot play a good role in resisting the invasion of combustion gas, and ablation is also likely to occur at the corners. With the improvement of the performance parameters of gas turbines, the temperature in the combustion chamber is getting higher and higher, and the service life of ceramic heat insulation tiles has been greatly reduced, reducing the overall reliability of the gas turbine.

[0043] In summary, under the combined action of the obliquely ejected cooling gas and the hot combustion gas flow, the heat insulation tile provided in this application forms a cooling gas film on the surface of the upper cover plate 2, thus avoiding the direct impact of the hot combustion gas and effectively improving the heat resistance of the heat insulation tile. And it adopts an integrally formed metal material. Compared with ceramic materials, metal has obvious advantages in temperature gradient resistance and flexural strength, and can overcome the problem of ceramic tile fragmentation. By providing a plurality of second air outlet holes 8 on the four side edges 4 of the heat insulation tile, the cooling gas ejected from the second air outlet holes 8 impacts and cools the axial and circumferential gaps. This application combines film cooling and impingement cooling. The hot combustion gas inside the combustion chamber does not directly impact the surface of the heat insulation tile, improving the cooling effect of the cooling gas. The distribution gaps of the heat insulation tile are also fully cooled, maximizing the heat resistance of the heat insulation tile, avoiding ablation and deformation, increasing its service life, and ensuring the safety of the metal cylinder block of the combustion chamber. Changing the heat insulation tile from a concave sheet structure to a closed block structure effectively improves the cooling efficiency of the cooling gas and avoids the ablation and deformation of the heat insulation tile. It improves its heat resistance and increases its service life. The combined cooling method effectively protects the metal cylinder block of the combustion chamber.

[0044] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and replacements can still be made, and these improvements and replacements should also be regarded as the protection scope of the present invention.

Claims

1. A heat-insulating tile for a gas turbine combustion chamber, characterized in that, Comprising: A closed cavity (5), the heat shield being a curved block with a predetermined thickness, and the closed cavity (5) being provided inside the heat shield; A lower bottom plate (3), provided on the side where the heat shield contacts the combustion chamber cylinder block (1), the lower bottom plate (3) being provided with a cooling gas inlet, and the cooling gas entering the closed cavity (5) from the cooling gas inlet; An upper cover plate (2), integrally formed with the lower bottom plate (3), the outer side of the upper cover plate (2) being in contact with hot gas; a plurality of cooling air channels (6) are uniformly distributed on the upper cover plate (2), one end of the cooling air channel (6) communicating with the closed cavity (5), being the air inlet end; the other end of the cooling air channel (6) communicating with the combustion chamber, being the air outlet end; a first air outlet hole (7) is provided at the air outlet end of the cooling air channel (6); the cooling air channel (6) is inclined, and the cooling gas is obliquely ejected through the first air outlet hole (7) and jointly acts with the hot gas flow on the outer surface of the upper cover plate (2) to form a layer of cooling gas film; The cooling air channel (6) sequentially includes a cylindrical channel (61) and a gradually expanding channel (62) along the air outlet direction; The cross-section of the first air outlet hole (7) is trapezoidal, and the cooling air channel (6) is inclined towards the side of the lower bottom edge of the trapezoid.

2. The heat insulation tile of a gas turbine combustor according to claim 1, characterized in that, The circumferential side of the upper cover plate (2) is bent towards the lower bottom plate (3) side to form a side edge (4), the side edge (4) being integrally connected to the lower bottom plate (3), and a plurality of second air outlet holes (8) are provided on the side edge (4), and the second air outlet holes (8) are used to introduce cooling gas into the circumferential and axial gaps of the heat shield.

3. The heat insulation tile of the gas turbine combustor according to claim 2, wherein The axial centerlines of the cylindrical channel (61) and the gradually expanding channel (62) have the same slope.

4. The heat insulation tile of the gas turbine combustor according to claim 3, characterized in that, The gradually expanding channel (62) is wedge-shaped, and the diameter of the gradually expanding channel (62) increases sequentially along the length direction of the cooling air channel (6).

5. The heat insulation tile of the gas turbine combustor according to claim 1, characterized in that The first air outlet hole (7) includes a plurality of uniformly distributed first air outlet holes (7).

6. The heat insulation tile of the gas turbine combustor according to claim 2, wherein, The plurality of second air outlet holes (8) on the side edge (4) are uniformly arranged.

7. The heat insulation tile of the gas turbine combustor according to claim 6, characterized in that, The second air outlet hole (8) is bent along its length direction.

8. A thermal shield for a gas turbine combustor, characterized in that, Including multiple circles of heat shields, the multiple circles of heat shields being arranged axially along the combustion chamber, and the heat shield being the heat shield of the gas turbine combustion chamber according to any one of claims 1 to 7.

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