Combustion chamber for a power plant gas turbine assembly comprising a plurality of metallic heat shielding tiles with improved air cooling feature

Abstract

A combustion chamber (3) for a power plant gas turbine assembly (1) wherein the combustion chamber comprises an outer casing (7) and a plurality of heat shielding tile devices (8) supported by the outer casing; wherein at least one shielding tile device comprises: a metallic tile body (9) having an inner face (10) configured for facing the hot gas flow inside the combustion chamber and an opposite outer face (11) configured for facing a plenum obtained between the outer casing and the metallic tile body and fed by cooling air; a first plurality of first cooling pipes (12) fed by the cooling air wherein the first cooling pipes are arranged parallel each other forming a first layer (16) on the outer face of the metallic tile body; a second plurality of second cooling pipes (13) fed by the cooling air wherein the second cooling pipes are arranged parallel each other forming a second layer (17) on the first plurality of first cooling pipes.

Description

Field of the Invention

[0001] The present invention relates to the technical filed of the gas turbine assembly for power plants. As known, in a power plant gas turbine assembly (in the following only gas turbine) an incoming air flow is compressed by a compressor and mixed with an added fuel in a combustion chamber for producing a hot gas flow to be expanded in a turbine for generating a rotating work on a rotor in turn connected to a generator. Due to the high temperature, it is common to provide the inner surface of the combustion chamber with a plurality of heat shieling tiles arranged in rows. In view of the above, in this technical filed the present invention refers the technical problem of how to improve the cooling the heat shieling tiles when these tile are metallic tiles and the cooling medium is air.Description of prior art

[0002] As known, a gas turbine assembly for power plants comprises a compressor assembly, a combustor assembly and a turbine assembly. The compressor assembly is configured for compressing incoming air supplied at a compressor inlet. The compressed air leaving the compressor assembly flows into a volume (called "plenum") and from there into the combustor assembly. This combustor assembly comprises usually a plurality of burners configured for injecting fuel (oil and / or gas fuel) in the compressed air flow. The mixture of fuel and compressed air enters a combustion chamber where this mixture is combusted. The resulting hot gas flow leaves the combustion chamber and drives in rotation the turbine assembly that performs a work on the rotor (in turn connected to a power generator). As known, the turbine assembly comprises a plurality of stages, or rows, of rotating blades that are interposed by a plurality of stages, or rows, of stator vanes. The rotating blades are supported by the rotor whereas the stator vanes are supported by a casing (called "vane carrier") that is concentric and surrounding the turbine assembly.

[0003] In order to achieve a high efficiency, the hot gas flow has to disclose a very high turbine inlet temperature. However, in general this high temperature involves an undesired high NOx emission level. In order to reduce this emission and to increase operational flexibility without decreasing the efficiency, a so called "sequential" gas turbine is particularly suitable. In general, a sequential gas turbine comprises a first and a second combustor or a first and a second combustion stage wherein each combustor is provided with a plurality of burners and with at least a relative combustion chamber. Today at least two different kinds of sequential gas turbines are known. According to a first embodiment, the first and the second combustor are annular shaped and are physically separated by a stage of turbine blades, called high pressure turbine. Downstream the second combustor a second turbine unit is present (called low pressure turbine). According to a second embodiment of a sequential gas turbine, the gas turbine is not provided with the high pressure turbine and the combustor assembly is realized in form of a plurality of can-combustors arranged as a ring around the rotor. Each can-combustor comprises a first combustor and a second combustor arranged directly one downstream the other inside a common can shaped casing. These two example of gas turbine assemblies have been cited only as non-limiting examples wherein the present invention can be applied. Moreover, the present invention may also be applied in gas turbines having a single combustion stage.

[0004] As known, it is common to provide the inner surface of the combustion chamber with a heat shielding layer. According to the context of the present invention, this heat shielding layer is formed by a plurality of tiles arranged in circumferential rows on the inner surface of the combustion chamber casing, so as to define an essentially continuous heat-insulating surface. It is common to realize tiles made of metallic material and to use air as cooling medium. In order to improve the efficiency of the assembly, today there is the need to improve the air cooling feature of these metallic heat shielding tiles.

[0005] US2008127652 discloses a heat shielding tile for a combustion chamber of a gas turbine wherein this tile device comprises a plurality of cooling pipes parallel each other fed by cooling air.Disclosure of the invention

[0006] Accordingly, a primary object of the present invention is to provide a new and inventive combustion chamber for a power plant gas turbine assembly. In particular, scope to the present invention is to offer a metallic heat shielding tile having an improved air cooling feature for heat shielding the inner surface of the combustion chamber. According to the present invention, the combustion chamber may have any shape and the turbine assembly may be of any type. In general, a skill person in this field well know what a combustor chamber and a metallic heat shielding tile are and thus no additional details are due for the understanding of the context of the invention.

[0007] In general, a combustion chamber is a space, preferably but not limiting annular shaped, defined by an outer casing wherein an hot gas flow runs along a main direction M. Due to the high temperature of this hot gas, it is common to provide the combustor casing with a plurality of heat shielding tiles supported by the outer casing itself.

[0008] According to the present invention, at least one of the above heat shielding tiles is a new and inventive heat shielding tile device comprising: a metallic tile body (the skill person understands that the word tile means a body substantially flat or planar suitable for following the casing shape) having an inner face configured for facing the hot gas flow inside the combustion chamber and an opposite outer face, in this case a gap is present between the tile outer face and the casing inner surface; a plurality of first cooling pipes fed by cooling air, wherein the first cooling pipes are arranged parallel each other forming a first layer of cooling pipes, this first layer may be obtained directly on the outer face of the metallic tile body or the pipes may be realized in form of channels running inside the tile body itself (this last embodiment is preferable in terms of cooling efficiency and it can be realized by an additive process); a plurality of second cooling pipes fed by cooling air, wherein the second cooling pipes are arranged parallel each other forming a second layer, this first layer may be obtained on the first layer of cooling pipes or directly in the on the outer face of the metallic tile body if the first layer is embedded inside the tile itself.

[0009] Thus, according to the invention two layers of pipes are provided for cooling the tile device wherein, preferably, the tile body and the pipes are made as a single piece by using a metallic additive process, as SLM.

[0010] The cooling air entering the pipes are coming from a plenum (the skill person well knows what a plenum is, i.e. a dedicated isolated volume) called in this invention as tile plenum because it is preferably provided and obtained directly on the outer face of the tile body. Thus, the size of the tile is very small.

[0011] Each cooling pipe comprises an inlet facing the tile plenum and least an inlet air hole is provided for connecting the tile plenum to an outer cooling air source (for instance a plenum arranged outside the combustor casing).

[0012] Preferably, the cooling pipes of each layer are configured so that the cooling air flowing in two adjacent cooling pipes of the same layer is in counter flow.

[0013] Preferably, the cooling pipes of the first layer are orthogonal to the cooling pipes of the second layer.

[0014] Preferably, the cooling pipes of the first layer are parallel to the hot gas flow main direction M.

[0015] Preferably, a bolt is provided for fixing the metallic tile body to the combustion chamber outer casing; the bolt is orthogonal to the tile body and passing by a fixing hole obtained substantially in the middle of the tile body.

[0016] Preferably, a thermal barrier coating is provided on the inner face of the tile body.

[0017] According to the invention, the tile plenum comprises: a first plenum that may be called square or picture plenum because it comprises four connected portions obtained along the edges (as a channel running along the contour of the tile) of the outer face of the tile body (for this scope the edges of the outer face of the tile body comprises a raised portion towards the casing for realizing a space suitable for the plenum); and a second plenum that may be called bridge or rib plenum running in the middle of the outer face of the tile body for connecting two opposite portions of the square plenum.

[0018] According to the invention, the bridge plenum is parallel to the pipes of the second layer and two air inlet holes are provided for delivering air into the second plenum from a plenum outside the casing.

[0019] In detail, in this example the pipes and the tile plenum are connected as in the following for allowing the air to enter the pipes: some pipes of the first layer discloses inlets in a first portion and in a second opposite portion of the square plenum and outlets obtained on the outer face of the tile (substantially in the middle just upstream or downstream the bridge plenum); some pipes of the first layer discloses inlets in the bridge plenum and outlets obtained on the side faces of the tile body (outside the first portion and the second portion of the square plenum) for facing adjacent tiles (this solution avoid hot gas ingestion).

[0020] Thus, in general the pipes of the first layer do not run along the entire tile from a side to the opposite side but "each line" is divided in two pipes upstream and downstream the bridge plenum.

[0021] On the contrary, substantially all pipes of the second layer run along the entire tile from a side to the opposite side. Namely: some pipes of the second layer disclose inlets in a third portion of the square plenum and outlets facing a tile adjacent to the opposite fourth portion of the square plenum; and some pipes of the second layer disclose inlets in fourth portion of the square plenum and outlets facing a tile adjacent to the third portion of the square plenum.

[0022] Only the central pipes of the second layer (i.e. the pipes crossing the hole for the fixing bolt) disclose: inlets in the bridge plenum and outlets facing the tiles adjacent to the third portion and the fourth portion of the square plenum; or inlets in the third portion and in the fourth portion of the square plenum and outlets on the inner face (preferably at the bolt hole for cooling the bolt).

[0023] Preferably, also the tile plenum are made in a single piece by a selective adding process with the tile body and the pipes.

[0024] Finally, the present invention extends its protection to any power plant gas turbine assembly comprising: a compressor for compressing air; a combustion chamber for generating a hot gas flow having a main direction M; a turbine driven by the hot gas flow for rotating a rotor; a generator for converting the rotating work of the rotor; wherein the combustion chamber is a combustion chamber according to claim 1 and as foregoing described.

[0025] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. Other advantages and features of the invention will be apparent from the following description, drawings and claims.

[0026] The features of the invention believed to be novel are set forth with particularity in the appended claims.Brief description of drawings

[0027] Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

[0028] The invention itself, however, may be best understood by reference to the following detailed description of the invention, which describes an exemplary embodiment of the invention, taken in conjunction with the accompanying drawings, in which: figure 1 is a schematic view of a power plant gas turbine assembly that may be improved by the present invention; figure 2 is a schematic view of a portion of the combustion chamber of figure 1; figure 3 is a cross section view of an example of a heat shielding tile of the present invention coupled to the combustor casing; figure 4 is a schematic view of the outer face of the tile of figure 3 wherein two layers of cooling pipes are provided; figure 5 is a schematic view disclosing the cooling air flow flowing in the pipes of the first layer obtained on the outer face of the tile; figure 6 is a schematic view disclosing the cooling air flow flowing in the pipes of the second layer obtained on the first layer; figure 7 is a cross section view of the tile of figure 4 along the line VII and figures 8-10 are enlarged views of portions labelled as VIII, IX, and X in figure 7; figure 11 is a cross section view of the tile of figure 4 along the line XI and figures 12-14 are enlarged views of portions labelled as XII, XIII, and XIV in figure 7. Detailed description of preferred embodiments of the invention

[0029] In cooperation with attached drawings, the technical contents and detailed description of the present invention are described thereinafter according to preferred embodiments, being not used to limit its executing scope. Any equivalent variation and modification made according to appended claims is all covered by the claims claimed by the present invention.

[0030] Reference will now be made to the drawing figures to describe the present invention in detail. In particular, reference is made to figure 1 which is a schematic view of a power plant gas turbine assembly that may be improved by the present invention. In general, no particular feature is required for providing a power plant gas turbine assembly suitable to be improved by the present invention. Generally, a such gas turbine assembly is an assembly 1 as comprising: a compressor 2 for compressing air; a combustion chamber 3 for generating a hot gas flow having a main direction M; a turbine 4 driven by the hot gas flow for rotating a rotor 5; a generator 6 for converting the rotating work of the rotor 5.

[0031] Figure 2 is a schematic view of a portion of a combustion chamber. As disclosed, the combustion chamber 3 is limited by an outer casing 7 defining a channel for the hot gas M. On the inner face of the outer casing 7 a plurality of heat shielding tile 8 are provided. The reference 21 in figure 2 refers to holes realized in each tile for housing a bolt configured for fixing the tile to the casing. As known, these tiles are substantially flat and are configured for following the shape of the casing. According to the invention, each tile is a metallic tile made in a single piece by an additive process.

[0032] Figure 3 is a cross section view of an example of a heat shielding tile device according to the present invention coupled to the combustor casing. This figure discloses the presence of a tile body 9 having an inner face 10 facing the hot gas and an outer face 11 spaced and facing the casing 7. The body 9 is substantially flat and discloses raised edges projecting towards the casing. As it will be clear in the following, these raised edges allow to define a tile plenum fed by cooling air that coming from an outer plenum 19 enters the tile plenum 14 passing by air inlet holes 18. Reference 20 refers to fixing bolt connecting the tile to a swirlock assembly in turn coupled to the outer face of the casing.

[0033] Figure 4 is a schematic view of the tile device alone disclosing the outer face of the tile of figure 3. As disclosed, a plurality of parallel pipes 12 are obtained on the outer face or directly inside the tile body forming a first or inner layer 16 of pipes parallel to the hot gas flow M. On this first layer or on the outer face of the tile if the first layer is inside the tile itself, a plurality of parallel pipes 13 are provided for forming a second or outer layer 17 of pipes orthogonal to the hot gas flow M. As disclosed in this figure, the pipes 13 of the second layer 17 run along the entire face of the tile from the edge 24 to the opposite edge 25. On the contrary, the pipes 12 of the second layer 16 run from a central portion 15 of the tile to opposite edges 22 and 23. The central portion 15 and the edges 22, 23, 24 and 25 are actually part of the tile plenum so that air can enter from there the corresponding pipes and flow towards the corresponding outlet, that may be facing adjacent tiles or obtained on the outer or on the inner face of the tile. Thus, the tile plenum of this example comprises: a square plenum 14 comprising four portions 22, 23, 24, 25 running along the edges of the outer face 11 of the tile body 9; and a bridge plenum 15 running in the middle of the outer face 11 of the tile body 9 connecting two opposite portions 24 25 of the square plenum.

[0034] Figure 5 is a schematic view disclosing the cooling air flow flowing in the pipes of the first layer. The circles refer to inlets of the pipes 12 and the arrows the outlets. In view of the above: some pipes 12 of the first layer 16 disclose inlets in the first 22 or in the second 23 opposite portion of the square plenum 14 and outlets on the outer face of the tile; and some pipes 12 of the first layer 16 disclose inlets in the bridge plenum 15 and outlets facing tiles adjacent to the first 22 and second 24 portions of the square plenum 14.

[0035] Figure 6 is a schematic view disclosing the cooling air flow flowing in the pipes of the second layer obtained on the first layer. The circles refer to inlets of the pipes 13 and the arrows the outlets. In view of the above: some pipes 13 of the second layer 17 disclose inlets in the third portion 24 of the square plenum 14 and outlets facing tiles adjacent to the opposite fourth portion 25 of the square plenum 14; and some pipes 13 of the second layer 17 disclose inlets in fourth portion 25 of the square plenum 14 and outlets facing tiles adjacent to the third portion 24 of the square plenum 14.

[0036] As disclosed in figure 6, only some central pipes 13 of the second layer 17 have inlets in the bridge plenum 15 and outlets facing tiles adjacent to the third 24 and fourth 25 portion of the square plenum 14. Alternatively or in combination, some central pipes 13 of the second layer 17 disclose inlets in the third 24 and fourth 25 portion of the square plenum and outlets on the inner face 10 of the tile 9 at the bolt hole 20.

[0037] Figure 7 is a cross section view of the tile of figure 4 along the line VII and figures 8-10 are enlarged views of portions labelled as VIII, IX, and X in figure 7. These figures allow to discloses how the air enter into the pipes 12 of the first layer and where are located the corresponding outlets. The pipe 12 in the right part of the tile discloses an inlet inside the portion 22 of the plenum 14 and outlet on the outer face of the tile upstream the bridge plenum 15. The pipe 12 in the right part of the tile discloses an inlet inside the bridge plenum 15 and an outlet facing the tile beyond the portion 23 of the plenum 14.

[0038] Figure 11 is a cross section view of the tile of figure 4 along the line XI and figures 12-14 are enlarged views of portions labelled as XII, XIII, and XIV in figure 7. These figures allow to discloses how the air enter into the central pipes 13 of the second layer and where are located the corresponding outlets. The pipe 13 in the right part of the tile discloses an inlet inside the bridge plenum 15 and outlet facing the tile beyond the portion 24 of the plenum 14. The pipe 13 in the right part of the tile discloses an inlet inside the portion 25 of the plenum 14 and an outlet on the inner face of the tile at the hole 21 housing the bolt 20. Apart the central pipes 13, the remaining pipes 13 of the second layer run along the entire tile body from side to opposite side taking air from one edge of the plenum and discarding air outside the opposite edge.

[0039] Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.

Examples

Embodiment Construction

[0029]In cooperation with attached drawings, the technical contents and detailed description of the present invention are described thereinafter according to preferred embodiments, being not used to limit its executing scope. Any equivalent variation and modification made according to appended claims is all covered by the claims claimed by the present invention.

[0030]Reference will now be made to the drawing figures to describe the present invention in detail. In particular, reference is made to figure 1 which is a schematic view of a power plant gas turbine assembly that may be improved by the present invention. In general, no particular feature is required for providing a power plant gas turbine assembly suitable to be improved by the present invention. Generally, a such gas turbine assembly is an assembly 1 as comprising:

a compressor 2 for compressing air; a combustion chamber 3 for generating a hot gas flow having a main direction M; a turbine 4 driven by the hot gas flow for ...

Field of the Invention

[0001] The present invention relates to the technical filed of the gas turbine assembly for power plants. As known, in a power plant gas turbine assembly (in the following only gas turbine) an incoming air flow is compressed by a compressor and mixed with an added fuel in a combustion chamber for producing a hot gas flow to be expanded in a turbine for generating a rotating work on a rotor in turn connected to a generator. Due to the high temperature, it is common to provide the inner surface of the combustion chamber with a plurality of heat shieling tiles arranged in rows. In view of the above, in this technical filed the present invention refers the technical problem of how to improve the cooling the heat shieling tiles when these tile are metallic tiles and the cooling medium is air.Description of prior art

[0002] As known, a gas turbine assembly for power plants comprises a compressor assembly, a combustor assembly and a turbine assembly. The compressor assembly is configured for compressing incoming air supplied at a compressor inlet. The compressed air leaving the compressor assembly flows into a volume (called "plenum") and from there into the combustor assembly. This combustor assembly comprises usually a plurality of burners configured for injecting fuel (oil and / or gas fuel) in the compressed air flow. The mixture of fuel and compressed air enters a combustion chamber where this mixture is combusted. The resulting hot gas flow leaves the combustion chamber and drives in rotation the turbine assembly that performs a work on the rotor (in turn connected to a power generator). As known, the turbine assembly comprises a plurality of stages, or rows, of rotating blades that are interposed by a plurality of stages, or rows, of stator vanes. The rotating blades are supported by the rotor whereas the stator vanes are supported by a casing (called "vane carrier") that is concentric and surrounding the turbine assembly.

[0003] In order to achieve a high efficiency, the hot gas flow has to disclose a very high turbine inlet temperature. However, in general this high temperature involves an undesired high NOx emission level. In order to reduce this emission and to increase operational flexibility without decreasing the efficiency, a so called "sequential" gas turbine is particularly suitable. In general, a sequential gas turbine comprises a first and a second combustor or a first and a second combustion stage wherein each combustor is provided with a plurality of burners and with at least a relative combustion chamber. Today at least two different kinds of sequential gas turbines are known. According to a first embodiment, the first and the second combustor are annular shaped and are physically separated by a stage of turbine blades, called high pressure turbine. Downstream the second combustor a second turbine unit is present (called low pressure turbine). According to a second embodiment of a sequential gas turbine, the gas turbine is not provided with the high pressure turbine and the combustor assembly is realized in form of a plurality of can-combustors arranged as a ring around the rotor. Each can-combustor comprises a first combustor and a second combustor arranged directly one downstream the other inside a common can shaped casing. These two example of gas turbine assemblies have been cited only as non-limiting examples wherein the present invention can be applied. Moreover, the present invention may also be applied in gas turbines having a single combustion stage.

[0004] As known, it is common to provide the inner surface of the combustion chamber with a heat shielding layer. According to the context of the present invention, this heat shielding layer is formed by a plurality of tiles arranged in circumferential rows on the inner surface of the combustion chamber casing, so as to define an essentially continuous heat-insulating surface. It is common to realize tiles made of metallic material and to use air as cooling medium. In order to improve the efficiency of the assembly, today there is the need to improve the air cooling feature of these metallic heat shielding tiles.

[0005] US2008127652 discloses a heat shielding tile for a combustion chamber of a gas turbine wherein this tile device comprises a plurality of cooling pipes parallel each other fed by cooling air.Disclosure of the invention

[0006] Accordingly, a primary object of the present invention is to provide a new and inventive combustion chamber for a power plant gas turbine assembly. In particular, scope to the present invention is to offer a metallic heat shielding tile having an improved air cooling feature for heat shielding the inner surface of the combustion chamber. According to the present invention, the combustion chamber may have any shape and the turbine assembly may be of any type. In general, a skill person in this field well know what a combustor chamber and a metallic heat shielding tile are and thus no additional details are due for the understanding of the context of the invention.

[0007] In general, a combustion chamber is a space, preferably but not limiting annular shaped, defined by an outer casing wherein an hot gas flow runs along a main direction M. Due to the high temperature of this hot gas, it is common to provide the combustor casing with a plurality of heat shielding tiles supported by the outer casing itself.

[0008] According to the present invention, at least one of the above heat shielding tiles is a new and inventive heat shielding tile device comprising: a metallic tile body (the skill person understands that the word tile means a body substantially flat or planar suitable for following the casing shape) having an inner face configured for facing the hot gas flow inside the combustion chamber and an opposite outer face, in this case a gap is present between the tile outer face and the casing inner surface; a plurality of first cooling pipes fed by cooling air, wherein the first cooling pipes are arranged parallel each other forming a first layer of cooling pipes, this first layer may be obtained directly on the outer face of the metallic tile body or the pipes may be realized in form of channels running inside the tile body itself (this last embodiment is preferable in terms of cooling efficiency and it can be realized by an additive process); a plurality of second cooling pipes fed by cooling air, wherein the second cooling pipes are arranged parallel each other forming a second layer, this first layer may be obtained on the first layer of cooling pipes or directly in the on the outer face of the metallic tile body if the first layer is embedded inside the tile itself.

[0009] Thus, according to the invention two layers of pipes are provided for cooling the tile device wherein, preferably, the tile body and the pipes are made as a single piece by using a metallic additive process, as SLM.

[0010] The cooling air entering the pipes are coming from a plenum (the skill person well knows what a plenum is, i.e. a dedicated isolated volume) called in this invention as tile plenum because it is preferably provided and obtained directly on the outer face of the tile body. Thus, the size of the tile is very small.

[0011] Each cooling pipe comprises an inlet facing the tile plenum and least an inlet air hole is provided for connecting the tile plenum to an outer cooling air source (for instance a plenum arranged outside the combustor casing).

[0012] Preferably, the cooling pipes of each layer are configured so that the cooling air flowing in two adjacent cooling pipes of the same layer is in counter flow.

[0013] Preferably, the cooling pipes of the first layer are orthogonal to the cooling pipes of the second layer.

[0014] Preferably, the cooling pipes of the first layer are parallel to the hot gas flow main direction M.

[0015] Preferably, a bolt is provided for fixing the metallic tile body to the combustion chamber outer casing; the bolt is orthogonal to the tile body and passing by a fixing hole obtained substantially in the middle of the tile body.

[0016] Preferably, a thermal barrier coating is provided on the inner face of the tile body.

[0017] According to the invention, the tile plenum comprises: a first plenum that may be called square or picture plenum because it comprises four connected portions obtained along the edges (as a channel running along the contour of the tile) of the outer face of the tile body (for this scope the edges of the outer face of the tile body comprises a raised portion towards the casing for realizing a space suitable for the plenum); and a second plenum that may be called bridge or rib plenum running in the middle of the outer face of the tile body for connecting two opposite portions of the square plenum.

[0018] According to the invention, the bridge plenum is parallel to the pipes of the second layer and two air inlet holes are provided for delivering air into the second plenum from a plenum outside the casing.

[0019] In detail, in this example the pipes and the tile plenum are connected as in the following for allowing the air to enter the pipes: some pipes of the first layer discloses inlets in a first portion and in a second opposite portion of the square plenum and outlets obtained on the outer face of the tile (substantially in the middle just upstream or downstream the bridge plenum); some pipes of the first layer discloses inlets in the bridge plenum and outlets obtained on the side faces of the tile body (outside the first portion and the second portion of the square plenum) for facing adjacent tiles (this solution avoid hot gas ingestion).

[0020] Thus, in general the pipes of the first layer do not run along the entire tile from a side to the opposite side but "each line" is divided in two pipes upstream and downstream the bridge plenum.

[0021] On the contrary, substantially all pipes of the second layer run along the entire tile from a side to the opposite side. Namely: some pipes of the second layer disclose inlets in a third portion of the square plenum and outlets facing a tile adjacent to the opposite fourth portion of the square plenum; and some pipes of the second layer disclose inlets in fourth portion of the square plenum and outlets facing a tile adjacent to the third portion of the square plenum.

[0022] Only the central pipes of the second layer (i.e. the pipes crossing the hole for the fixing bolt) disclose: inlets in the bridge plenum and outlets facing the tiles adjacent to the third portion and the fourth portion of the square plenum; or inlets in the third portion and in the fourth portion of the square plenum and outlets on the inner face (preferably at the bolt hole for cooling the bolt).

[0023] Preferably, also the tile plenum are made in a single piece by a selective adding process with the tile body and the pipes.

[0024] Finally, the present invention extends its protection to any power plant gas turbine assembly comprising: a compressor for compressing air; a combustion chamber for generating a hot gas flow having a main direction M; a turbine driven by the hot gas flow for rotating a rotor; a generator for converting the rotating work of the rotor; wherein the combustion chamber is a combustion chamber according to claim 1 and as foregoing described.

[0025] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. Other advantages and features of the invention will be apparent from the following description, drawings and claims.

[0026] The features of the invention believed to be novel are set forth with particularity in the appended claims.Brief description of drawings

[0027] Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

[0028] The invention itself, however, may be best understood by reference to the following detailed description of the invention, which describes an exemplary embodiment of the invention, taken in conjunction with the accompanying drawings, in which: figure 1 is a schematic view of a power plant gas turbine assembly that may be improved by the present invention; figure 2 is a schematic view of a portion of the combustion chamber of figure 1; figure 3 is a cross section view of an example of a heat shielding tile of the present invention coupled to the combustor casing; figure 4 is a schematic view of the outer face of the tile of figure 3 wherein two layers of cooling pipes are provided; figure 5 is a schematic view disclosing the cooling air flow flowing in the pipes of the first layer obtained on the outer face of the tile; figure 6 is a schematic view disclosing the cooling air flow flowing in the pipes of the second layer obtained on the first layer; figure 7 is a cross section view of the tile of figure 4 along the line VII and figures 8-10 are enlarged views of portions labelled as VIII, IX, and X in figure 7; figure 11 is a cross section view of the tile of figure 4 along the line XI and figures 12-14 are enlarged views of portions labelled as XII, XIII, and XIV in figure 7. Detailed description of preferred embodiments of the invention

[0029] In cooperation with attached drawings, the technical contents and detailed description of the present invention are described thereinafter according to preferred embodiments, being not used to limit its executing scope. Any equivalent variation and modification made according to appended claims is all covered by the claims claimed by the present invention.

[0030] Reference will now be made to the drawing figures to describe the present invention in detail. In particular, reference is made to figure 1 which is a schematic view of a power plant gas turbine assembly that may be improved by the present invention. In general, no particular feature is required for providing a power plant gas turbine assembly suitable to be improved by the present invention. Generally, a such gas turbine assembly is an assembly 1 as comprising: a compressor 2 for compressing air; a combustion chamber 3 for generating a hot gas flow having a main direction M; a turbine 4 driven by the hot gas flow for rotating a rotor 5; a generator 6 for converting the rotating work of the rotor 5.

[0031] Figure 2 is a schematic view of a portion of a combustion chamber. As disclosed, the combustion chamber 3 is limited by an outer casing 7 defining a channel for the hot gas M. On the inner face of the outer casing 7 a plurality of heat shielding tile 8 are provided. The reference 21 in figure 2 refers to holes realized in each tile for housing a bolt configured for fixing the tile to the casing. As known, these tiles are substantially flat and are configured for following the shape of the casing. According to the invention, each tile is a metallic tile made in a single piece by an additive process.

[0032] Figure 3 is a cross section view of an example of a heat shielding tile device according to the present invention coupled to the combustor casing. This figure discloses the presence of a tile body 9 having an inner face 10 facing the hot gas and an outer face 11 spaced and facing the casing 7. The body 9 is substantially flat and discloses raised edges projecting towards the casing. As it will be clear in the following, these raised edges allow to define a tile plenum fed by cooling air that coming from an outer plenum 19 enters the tile plenum 14 passing by air inlet holes 18. Reference 20 refers to fixing bolt connecting the tile to a swirlock assembly in turn coupled to the outer face of the casing.

[0033] Figure 4 is a schematic view of the tile device alone disclosing the outer face of the tile of figure 3. As disclosed, a plurality of parallel pipes 12 are obtained on the outer face or directly inside the tile body forming a first or inner layer 16 of pipes parallel to the hot gas flow M. On this first layer or on the outer face of the tile if the first layer is inside the tile itself, a plurality of parallel pipes 13 are provided for forming a second or outer layer 17 of pipes orthogonal to the hot gas flow M. As disclosed in this figure, the pipes 13 of the second layer 17 run along the entire face of the tile from the edge 24 to the opposite edge 25. On the contrary, the pipes 12 of the second layer 16 run from a central portion 15 of the tile to opposite edges 22 and 23. The central portion 15 and the edges 22, 23, 24 and 25 are actually part of the tile plenum so that air can enter from there the corresponding pipes and flow towards the corresponding outlet, that may be facing adjacent tiles or obtained on the outer or on the inner face of the tile. Thus, the tile plenum of this example comprises: a square plenum 14 comprising four portions 22, 23, 24, 25 running along the edges of the outer face 11 of the tile body 9; and a bridge plenum 15 running in the middle of the outer face 11 of the tile body 9 connecting two opposite portions 24 25 of the square plenum.

[0034] Figure 5 is a schematic view disclosing the cooling air flow flowing in the pipes of the first layer. The circles refer to inlets of the pipes 12 and the arrows the outlets. In view of the above: some pipes 12 of the first layer 16 disclose inlets in the first 22 or in the second 23 opposite portion of the square plenum 14 and outlets on the outer face of the tile; and some pipes 12 of the first layer 16 disclose inlets in the bridge plenum 15 and outlets facing tiles adjacent to the first 22 and second 24 portions of the square plenum 14.

[0035] Figure 6 is a schematic view disclosing the cooling air flow flowing in the pipes of the second layer obtained on the first layer. The circles refer to inlets of the pipes 13 and the arrows the outlets. In view of the above: some pipes 13 of the second layer 17 disclose inlets in the third portion 24 of the square plenum 14 and outlets facing tiles adjacent to the opposite fourth portion 25 of the square plenum 14; and some pipes 13 of the second layer 17 disclose inlets in fourth portion 25 of the square plenum 14 and outlets facing tiles adjacent to the third portion 24 of the square plenum 14.

[0036] As disclosed in figure 6, only some central pipes 13 of the second layer 17 have inlets in the bridge plenum 15 and outlets facing tiles adjacent to the third 24 and fourth 25 portion of the square plenum 14. Alternatively or in combination, some central pipes 13 of the second layer 17 disclose inlets in the third 24 and fourth 25 portion of the square plenum and outlets on the inner face 10 of the tile 9 at the bolt hole 20.

[0037] Figure 7 is a cross section view of the tile of figure 4 along the line VII and figures 8-10 are enlarged views of portions labelled as VIII, IX, and X in figure 7. These figures allow to discloses how the air enter into the pipes 12 of the first layer and where are located the corresponding outlets. The pipe 12 in the right part of the tile discloses an inlet inside the portion 22 of the plenum 14 and outlet on the outer face of the tile upstream the bridge plenum 15. The pipe 12 in the right part of the tile discloses an inlet inside the bridge plenum 15 and an outlet facing the tile beyond the portion 23 of the plenum 14.

[0038] Figure 11 is a cross section view of the tile of figure 4 along the line XI and figures 12-14 are enlarged views of portions labelled as XII, XIII, and XIV in figure 7. These figures allow to discloses how the air enter into the central pipes 13 of the second layer and where are located the corresponding outlets. The pipe 13 in the right part of the tile discloses an inlet inside the bridge plenum 15 and outlet facing the tile beyond the portion 24 of the plenum 14. The pipe 13 in the right part of the tile discloses an inlet inside the portion 25 of the plenum 14 and an outlet on the inner face of the tile at the hole 21 housing the bolt 20. Apart the central pipes 13, the remaining pipes 13 of the second layer run along the entire tile body from side to opposite side taking air from one edge of the plenum and discarding air outside the opposite edge.

[0039] Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.

Examples

Embodiment Construction

[0029]In cooperation with attached drawings, the technical contents and detailed description of the present invention are described thereinafter according to preferred embodiments, being not used to limit its executing scope. Any equivalent variation and modification made according to appended claims is all covered by the claims claimed by the present invention.

[0030]Reference will now be made to the drawing figures to describe the present invention in detail. In particular, reference is made to figure 1 which is a schematic view of a power plant gas turbine assembly that may be improved by the present invention. In general, no particular feature is required for providing a power plant gas turbine assembly suitable to be improved by the present invention. Generally, a such gas turbine assembly is an assembly 1 as comprising:

a compressor 2 for compressing air; a combustion chamber 3 for generating a hot gas flow having a main direction M; a turbine 4 driven by the hot gas flow for ...

Claims

1. Combustion chamber (3) for a power plant gas turbine assembly (1); wherein the combustion chamber (3) comprises an outer casing (7) and a plurality of heat shielding tiles (8) supported by the outer casing (7); wherein at least one of the heat shielding tiles (8) is a heat shielding tile device comprising: - a metallic tile body (9) having an inner face (10) configured for facing the hot gas flow inside the combustion chamber and an opposite outer face (11); - a plurality of first cooling pipes (12) fed by cooling air, wherein the first cooling pipes are (12) arranged parallel each other forming a first layer (16) on the outer face (11) of or inside the metallic tile body (10), characterized in that the heat shielding tile also comprises: - a plurality of second cooling pipes (13) fed by cooling air, wherein the second cooling pipes (13) are arranged parallel each other forming a second layer (17) on the first layer (16) of cooling pipes (12) or on the outer face (11) of the metallic tile body (10); wherein a tile plenum (14, 15) fed by cooling air is provided on the outer face (11) of the tile body (10), each cooling pipe (12, 13) comprises an inlet facing the tile plenum (14, 15) ; wherein the tile plenum comprises: - a square plenum (14) comprising four portions (22, 23, 24, 25) running along the edges of the outer face (11) of the tile body (9); and - a bridge plenum (15) running in the middle of the outer face (11) of the tile body (9) connecting two opposite portions of the square plenum; wherein the bridge plenum (15) is parallel to the pipes (13) of the second layer (17).

2. Combustion chamber as claimed in claim 1, wherein at least an inlet air hole (18) is provided for connecting the tile plenum (14, 15) to a cooling air source (19).

3. Combustion chamber as claimed in any one of the foregoing claims, wherein the cooling pipes (12, 13) of each layer (16, 17) are configured so that the cooling air flowing into two adjacent cooling pipes (12, 13) of the same layer is in counter flow (16, 17).

4. Combustion chamber as claimed in any one of the foregoing claims, wherein the cooling pipes (12) of the first layer (16) are orthogonal to the cooling pipes (13) of the second layer (17).

5. Combustion chamber as claimed in any one of the foregoing claims, wherein inside the combustion chamber the hot gas flow discloses a main direction (M), the cooling pipes (12) of the first layer (16) being parallel to the hot gas flow main direction (M).

6. Combustion chamber as claimed in any one of the foregoing claims, wherein a bolt (20) is provided for fixing the metallic tile body (9) to the combustion chamber outer casing (7); the bolt (20) is orthogonal to the tile body (9) and passing by a fixing hole (21) obtained substantially in the middle of the tile body (9).

7. Combustion chamber as claimed in any one of the foregoing claims, wherein a thermal barrier coating is provided applied on the inner face (10) of the tile body (9).

8. Combustion chamber as claimed in claim 1, wherein some pipes (12) of the first layer (16) disclose inlets in a first (22) and in a second (23) opposite portions of the square plenum (14) and outlets on the outer face of the tile (9); and wherein some pipes (12) of the first layer (16) disclose inlets in the bridge plenum (15) and outlets facing tiles adjacent to the first (22) and second (24) portions of the square plenum (14).

9. Combustion chamber as claimed in claim 8, wherein some pipes (13) of the second layer (17) disclose inlets in a third portion (24) of the square plenum (14) and outlets facing a tile adjacent to the opposite fourth portion (25) of the square plenum (14); and wherein some pipes (13) of the second layer (17) disclose inlets in fourth portion (25) of the square plenum (14) and outlets facing a tile adjacent to the third portion (24) of the square plenum (14).

10. Combustion chamber as claimed in claim 8, wherein some central pipes (13) of the second layer (17) disclose inlets in the bridge plenum (15) and outlets facing the tiles adjacent to the third (24) and fourth (25) portion of the square plenum (14); and wherein some central pipes (13) of the second layer (17) disclose inlets in the (24) and fourth (25) of the square plenum and outlets on the inner face (109 of the tile (9).

11. Combustion chamber as claimed in any one of the foregoing claims, wherein the tile body, the pipes and the tile plenum are made in a single piece by a selective adding process.

12. A power plant gas turbine assembly (1) comprising: - a compressor (2) for compressing air; - a combustion chamber (3) according to claim 1 for generating a hot gas flow having a main direction (M); - a turbine (4) driven by the hot gas flow for rotating a rotor (5); - a generator (6) for converting the rotating work of the rotor (5).

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