Abstract:
A heat shield tile detachably arranged on a bearing structure of a heat shield by at least one retaining element. The heat shield tile has a cold side facing the bearing structure, a hot side, arranged opposite the cold side and to which hot gases can be applied, and lateral surfaces that connect the cold side to the hot side. The heat shield tile reduces the amount of cooling air needed to flush the expansion gaps between the heat shield tiles of the heat shield. The heat shield tile has a main body and a number of segments. The segments are arranged adjacent to each other on the main body over the entire area of the main body such that expansion gaps are left. The segments are joined to the main body, such that at least the hot side of the heat shield tile is substantially formed by the segments.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is the US National Stage of International Application No. PCT/EP2014/059065 filed 5 May 2014, and claims the benefit thereof. The International Application claims the benefit of German Application No. DE 102013209284.9 filed 21 May 2013. All of the applications are incorporated by reference herein in their entirety. 
     
    
     FIELD OF INVENTION 
       [0002]    The invention relates to a heat shield tile and to a heat shield having at least one such heat shield tile. The invention also relates to a combustion chamber lined with such a heat shield and to a gas turbine and to a method for producing the heat shield tile. 
       BACKGROUND OF INVENTION 
       [0003]    In many technical applications, use is made of heat shields which have to withstand hot gases at 1000 to 1600 degrees Celsius. In particular, gas turbines, such as are used in current-generating power plants and in aircraft engines, have accordingly large surfaces, which are to be shielded by means of heat shields, within the combustion chambers. Due to the thermal expansion and because of the large dimensions of the combustion chambers, the heat shield must be composed of a multiplicity of individual, generally ceramic heat shield tiles (heat shield bricks) which are attached to a supporting structure spaced apart from one another with a sufficient gap. This gap provides the heat shield tiles, which can also be termed heat shield elements, with sufficient space for thermal expansion. However, since the gap also allows the hot combustion gases to come into direct contact with the metallic supporting structure and the retaining elements, it is possible as a countermeasure for cooling air to be injected through the gaps in the direction of the combustion chamber. 
         [0004]    EP 1 557 611 A1 discloses a gas turbine combustion chamber which is lined internally with a heat shield. The heat shield comprises a supporting structure and a number of heat shield tiles which consist of a ceramic material and are releasably attached to the supporting structure by means of retaining elements. For the purpose of protecting the combustion chamber wall, the heat shield tiles are arranged in a surface-covering manner on the supporting structure while leaving expansion gaps, wherein each heat shield tile has a cold side oriented toward the supporting structure and, arranged on the opposite side from the cold side, a hot side which can be exposed to a hot medium. The cold side and the hot side are connected by side faces of the heat shield tile. The retaining elements holding the heat shield tile engage in each of two opposing side faces such that the retaining elements are exposed to the hot gases entering the expansion gaps. In order to avoid scaling of the retaining elements and of the supporting structure, cooling air is therefore guided into the expansion gaps from the direction of the supporting structure. However, the more cooling air is used for this purpose, the worse the exhaust gas values of the gas turbine and the lower the overall efficiency of the power generation. For that reason, EP 1 557 611 A1 proposes arranging sealing elements in the expansion gaps in order to reduce the required quantity of cooling air. 
         [0005]    EP 1 715 249 A1 discloses a heat shield element for lining combustion chambers guiding hot gas, which element has a hot-side surface which is to be oriented toward the hot gas and is characterized in that the hot-side surface is provided with depressions and/or projections. 
       SUMMARY OF INVENTION 
       [0006]    The present invention has an object of indicating a heat shield tile as mentioned in the introduction, a heat shield having at least one such heat shield tile and a combustion chamber lined with the heat shield and a gas turbine with which the quantity of cooling air which is required for flushing the expansion gaps between the heat shield tiles can be particularly effectively reduced. 
         [0007]    This object is achieved according to the invention with a heat shield tile of the type mentioned in the introduction, in that the heat shield tile comprises a base body and a number of segments, wherein the segments are arranged on the base body, adjoining one another, so as to cover the entire surface while leaving expansion gaps and are joined to the base body such that at least the hot side of the heat shield tile is formed essentially of the segments. 
         [0008]    The heat shield tile constructed according to the invention makes it possible to increase the dimensions of the heat shield tile along the edges of the hot and cold sides, in comparison to conventional heat shield tiles. In the case of a heat shield having at least one such heat shield tile, this leads, in the region of the latter, to a reduction in the expansion gaps per unit of surface area, and thus to a reduction in the quantity of cooling air required overall. 
         [0009]    According to the invention, the heat shield tile has a hybrid construction comprising at least one base body and the segments arranged thereon and joined therewith. The segmentation of the hottest parts of the hybrid structure permits a reduction in thermally induced stresses. The segments and the base body may for example have comparable dimensions perpendicular to the supporting structure. The base body is less exposed to the thermally induced stresses caused by the hot gases than are for example the segments, such that its base area can accordingly be made bigger. Since the base body and the segments are joined together, the segments can have, without limiting their dimensions and perpendicular to the supporting structure, a thickness required for the desired thermal barrier effect, wherein it is merely necessary to select a joining technology suitable for the weight of the segment in order to join the segment and base body. For example, the use of an adhesive joining technology is particularly suitable on account of the base areas of the segments being small as a consequence of the segmentation. For such an adhesive material bond, use is for example made of adhesives and cements which, after curing, consist essentially of inorganic components. 
         [0010]    Joining together the heat shield tile from different structures also permits separate production of the base body and of the segments. 
         [0011]    This has the further advantage that it is possible to optimize the materials and the production methods for the function of the structures to be joined together. It is thus possible for the base body for example to be made of a material that is more stable—albeit less resistant to high temperatures—than that of the segments. This makes it possible to further increase the dimensions of the heat shield tile along the edges of the cold and hot sides. A further advantage of the invention is that, on account of the larger dimensions of the heat shield tile, fewer retaining elements per unit of surface area are required overall. 
         [0012]    One advantageous embodiment of the invention can provide that the segments are adhesively bonded to adhesive bonding regions of the base body. 
         [0013]    The adhesive layer is exposed to lower temperatures than is the hot side of the heat shield tile. The adhesive can for example be Ceramabond 503 from Aremco. Further exemplary embodiments for the adhesive may be adhesive systems having a phosphatic or silicatic binder phase. 
         [0014]    Adhesive bonding of large surfaces is technologically very demanding. In particular, ensuring an exact fit between the complementary faces, which is a precondition for an even thickness of the adhesive layer, is very onerous. Since the inventive construction of the heat shield tile provides for segmentation and thus reduction in the surfaces to be bonded with respect to a layered construction, the joining technology indicated according to the advantageous embodiment of the invention can be used particularly efficiently. 
         [0015]    It can also be considered advantageous that the mechanical stability of the heat shield tile is ensured for the most part by the base body. 
         [0016]    This makes it possible to dispense with unnecessary material requirements for the segments, such that material costs can be saved. 
         [0017]    It can advantageously be further provided that the at least one retaining element can be arranged on the base body. 
         [0018]    The retaining element is thus expediently attached to the base body, which is capable of withstanding greater mechanical loads. 
         [0019]    According to a further advantageous embodiment of the invention, the base body can be made of a metallic material and/or a monolithic ceramic and/or a ceramic matrix composite and/or a high-temperature refractory ceramic. 
         [0020]    The metal may for example be IN718 (trade name of Special Metals Corporation), MAR-M-247 or MAR-M-509 (trade names of Martin Marietta). The monolithic ceramic may for example be Si 3 N 4 , ZrO 2 , mullite or SiC. 
         [0021]    The fibers of the ceramic matrix composite may for example consist of Nextel 610, Nextel 720 (trade name of 3M), Al 2 O 3 , mullite or SiC. 
         [0022]    The high-strength refractory ceramic can be made on the basis of Al 2 O 3 , mullite, corundum, SiC or zirconium. 
         [0023]    It can further be advantageously provided that a high-temperature resistance and/or a thermal barrier property and/or a corrosion resistance of the heat shield tile is ensured essentially by means of the segments. 
         [0024]    This makes it possible to dispense with unnecessary material requirements for the base body, such that material costs can be saved. 
         [0025]    In order to produce the three named properties of the segments, these can themselves have a layered construction. This makes it possible to save further material costs. 
         [0026]    For example, the segments can be made of a high-temperature ceramic or a high-temperature ceramic system. For example, the ceramic may be zirconium oxide with one or more stabilizers. According to a further exemplary embodiment of the configuration of the invention, the material of the segments can also be FGI material (Siemens). 
         [0027]    A further advantageous configuration of the invention can provide that the connection surfaces between the segments and the base body are structured or roughened. 
         [0028]    This makes the connection between the segments and the base body, in particular an adhesive connection, more secure. 
         [0029]    Advantageously, the connection surfaces can have grooves and/or bumps. 
         [0030]    These structures are particularly simple to produce and permit an advantageous enlargement of the adhesive bonding faces. 
         [0031]    It can also be considered advantageous that the segments are, exclusively or in addition to a material-bonded connection, arranged on the base body in a force-fitting and/or form-fitting manner. 
         [0032]    For applications which require very high reliability of the hybrid heat shield tile, and in which the loss of a segment cannot be tolerated, this configuration of the invention permits a particularly secure connection between the segment and the base body. The force-fitting connection can be realized for example by mutually engaging structures of the connection surfaces. For example, the adhesive bonding surfaces can have mutually engaging structures corresponding to a dovetail connection, wherein the attachment of a segment to such an adhesive bonding surface can be performed by means of an assembly movement parallel to the hot side. 
         [0033]    One advantageous configuration of the invention can, in order to further secure the connection between the segment and the base body, provide at least one reinforcing element which connects a segment to the base body or a segment to an adjacent segment. 
         [0034]    The reinforcing element can for example consist of monolithic ceramic, for example of Si 3 N 4 , Al 2 O 3 , SiC or ZrO 2 . In order to attach the reinforcing element to the segment and to the base body, it is possible, for example when producing one of the components in the case of a ceramic material, for the reinforcing element to simply be cast concomitantly during the casting process of the component. In order to attach the component to the respective other component, the reinforcing element can for example be screwed and/or adhesively bonded into the other component. The reinforcing element thus secures, in a redundant manner, the connection between the two components in addition to an adhesively bonded connection which is for example provided. 
         [0035]    A particularly secure and simple to manipulate attachment of the reinforcing element on the base body can provide that the base body has, for receiving the reinforcing element, a cutout which extends as far as the cold side. The reinforcing element arranged on a segment can in this context be designed such that it extends along the cutout in the base body essentially as far as the cold side of the heat shield tile, and is connected to the base body. 
         [0036]    Advantageously, it is possible to provide at least one securing element which is arranged in the region of the cold side of the heat shield tile and is connected to at least one reinforcing element that extends essentially as far as the cold side. The reinforcing element extends along a cutout in the base body. 
         [0037]    A securing ring, arranged from the cold side around an end region of the reinforcing element, can for example serve to secure the reinforcing element in the cutout. A further exemplary embodiment of a securing element can be a strip, for example made of metal, into one longitudinal side of which notches are introduced, corresponding to the separations between the reinforcing elements projecting out of the cutouts on the cold side, which surround the ends of a row of reinforcing elements. It is thus possible to attach an entire group of reinforcing elements to the base body by means of such a securing clip. The securing element may for example consist of X11, IN718 (trade name of Special Metals Corporation) or MAR-M-509 (trade name of Martin Marietta). 
         [0038]    A further object of the invention is that of indicating a heat shield as mentioned in the introduction, with which the quantity of cooling air which is required for flushing the expansion gaps between the heat shield tiles can be particularly effectively reduced. 
         [0039]    This object is achieved according to the invention with a heat shield of the type mentioned in the introduction, in that at least one heat shield tile is formed as claimed. 
         [0040]    The inventive heat shield may comprise one or more heat shield tiles so formed. It is for example also possible for all of the heat shield tiles of the heat shield to be formed as claimed. In order to further increase the saving in terms of cooling air, it is possible to arrange seal materials such as wovens, foams or windings in the expansion gaps between the heat shield tiles. 
         [0041]    A further object of the invention is that of indicating a combustion chamber lined with a heat shield as mentioned in the introduction and a gas turbine having such a combustion chamber, with which the quantity of cooling air which is required for flushing the expansion gaps between the heat shield tiles can be particularly effectively reduced. 
         [0042]    This object is achieved with a combustion chamber and a gas turbine of the type mentioned in the introduction in that the heat shield is formed as claimed. 
         [0043]    A further object of the invention is that of indicating a method for producing a heat shield tile of the type mentioned in the introduction, with which the quantity of cooling air which is required for flushing the expansion gaps between the heat shield tiles can be particularly effectively reduced. 
         [0044]    This object is achieved with a method of the specified type in that, in order to construct the heat shield tile,—a base body and a number of segments are produced, and—the segments are arranged adjoining one another in a surface-covering manner on the base body while leaving expansion gaps, and are joined to the base body,—wherein the segments are arranged on the base body at least in the region of the hot side of the heat shield tile, such that the hot side of the heat shield tile is formed essentially by surface regions of the segments. 
         [0045]    With regard to the advantages of the heat shield tile produced by means of the method, see the above remarks relating to the claims. 
         [0046]    The segments and the base body may have partially common production steps. This is in particular the case if they are made of the same material. For example, the segments may be sawn out of a common piece of material. In addition, the sequence, indicated in the claim, of the method steps of producing the segments/base body and of arranging the segments on the base body does not necessarily correspond to a temporal sequence of the two method steps. The segments may for example grow on the base body by means of laser sintering methods. The joining of segments and base body does not necessarily presuppose, within the context of this invention, the prior separate existence of the components. All that is essential here is that, with the combination of the components used and the chosen joining technique, it is possible to achieve a separation in the functions of the components, such that the mechanical stability of the heat shield tile is ensured essentially by the base body and the thermal barrier property of the heat shield tile is ensured essentially by the segments. This is advantageously achieved by using the virtues of specialized materials. 
         [0047]    It can advantageously be provided that the segments are attached to the base body by means of a material-bonded connection, in particular by means of an adhesive connection. The connection properties can be further improved by structuring the connection faces between the segments and the base body. The structuring can be effected during production of the base body and of the segments, or can be introduced into these subsequently. 
         [0048]    It can also be considered advantageous for at least one reinforcing element to be arranged on a segment or the base body. When attaching the segment to the base body, the reinforcing element is attached to the respectively opposite component. 
         [0049]    The reinforcing element reinforces the connection between the segment and the base body or serves to secure the attachment in that it runs between the segment and the adjacent segment. The reinforcing element effectively counteracts separation and loss of the segment in the event of failure of the primary connection method. 
         [0050]    To that end, it can be advantageously provided that the reinforcing element is secured on the base body with a securing element. 
         [0051]    Further expedient configurations and advantages of the invention form the subject matter of the description of exemplary embodiments of the invention, with reference to the figures of the drawing, wherein identical reference signs relate to functionally identical components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0052]    In the figures: 
           [0053]      FIG. 1  shows a plan view of an exemplary embodiment of a heat shield tile according to the invention, with a plurality of segments; 
           [0054]      FIG. 2  shows a sectional representation through a heat shield tile according to  FIG. 1 ; 
           [0055]      FIG. 3  shows a plan view of a further exemplary embodiment of a heat shield tile according to the invention, with an alternative form of the segments; 
           [0056]      FIG. 4  shows a plan view of a further alternative exemplary embodiment of a heat shield tile according to the invention, with a further alternative segmentation of the segments; 
           [0057]      FIG. 5  shows a sectional representation through a segment according to the invention, according to a further exemplary embodiment having an additional mechanical reinforcing element for anchoring the segment on the base body; 
           [0058]      FIG. 6  shows a sectional representation through a corresponding base body according to the invention having a complementary receiving opening for the mechanical reinforcing element of FIGS; 
           [0059]      FIG. 7  shows the segment of  FIG. 5  and the base body of  FIG. 6  in the connected state; 
           [0060]      FIG. 8  shows an alternative embodiment of a heat shield tile according to the invention, having an additional mechanical reinforcing element between the segment and the base body and additional structuring of the connection face in the adhesive bonding region; 
           [0061]      FIG. 9  shows a sectional representation through an alternative embodiment of a heat shield tile according to the invention, having alternatively shaped additional mechanical reinforcing elements between the segments and the base body; 
           [0062]      FIG. 10  shows a sectional representation through an alternative embodiment of a heat shield tile according to the invention, which provides, in contrast to the exemplary embodiment represented in  FIG. 8 , additional adhesive bonding of the mechanical reinforcing elements in the base body; 
           [0063]      FIG. 11  shows a sectional representation through an alternative embodiment of a heat shield tile according to the invention, having alternatively shaped additional mechanical reinforcing elements between the segments and the base body, which is held in the supporting structure by adhesive bonding; 
           [0064]      FIG. 12  shows a sectional representation through an alternative embodiment of a heat shield tile according to the invention, having an additional mechanical reinforcing element between adjacent segments; 
           [0065]      FIG. 13  shows a plan view of an alternative embodiment of a heat shield tile according to the invention, having additional mechanical reinforcing elements between adjacent segments and between the segments and the base body; 
           [0066]      FIG. 14  shows a plan view of an alternative embodiment of a heat shield tile according to the invention, having additional mechanical reinforcing elements between adjacent segments and between the segments and the base body, and with an alternative segmentation; 
           [0067]      FIG. 15  shows a plan view of an alternative embodiment of a heat shield tile according to the invention, having additional mechanical reinforcing elements between adjacent segments and between the segments and the base body, and with an alternative segmentation; 
           [0068]      FIG. 16  shows a sectional representation through an alternative embodiment of a heat shield tile according to the invention, having additional mechanical reinforcing elements between the segments and the base body, and having an additional metallic securing element; 
           [0069]      FIG. 17  shows a plan view of the cold side of the heat shield tile of  FIG. 16 ; 
           [0070]      FIG. 18  shows a plan view of the cold side of an alternative embodiment of a heat shield tile according to the invention, having an alternative segmentation with respect to  FIG. 17 , and 
           [0071]      FIG. 19  shows a schematic representation of a gas turbine according to the prior art, in longitudinal section. 
       
    
    
     DETAILED DESCRIPTION OF INVENTION 
       [0072]      FIG. 1  shows a plan view of the hot side of an inventive heat shield tile  10 , according to one exemplary embodiment. The heat shield tile  10  comprises a base body (arranged below the segments  12  in the plan view and thus not visible—corresponding to position  14  in  FIG. 2 ) and a number of segments  12 , which are arranged on the base body, adjoining one another, so as to cover the entire surface while leaving expansion gaps  16  and are joined to the base body such that at least the hot side of the heat shield tile  10  is formed essentially of the segments  12 . In other words, the hot-side surface regions of the segments  12  essentially form the hot side of the heat shield tile  10 . 
         [0073]    The segments  12  need not necessarily have a rectangular circumferential contour as shown. What is essential is only that the segments  12  adjoin one another in a surface-covering manner while leaving expansion gaps  16 , such that it is possible to cover the base body toward the hot side. The size of the segments can be adapted on one hand to a desired maximum thermal stress within a segment  12  and on the other hand to the type of connection between the segment  12  and the base body. Thus, for example in the case of an adhesive connection, the base surface of the segments  12  should advantageously not be chosen too large in order that it is possible to ensure an even thickness of the adhesive layer. On account of the segmentation, each segment  12  is exposed in operation to only relatively low thermal gradients in its expansion direction, such that the total expansion and thus the resulting thermal stresses within the individual segment  12  can be kept low. 
         [0074]    The segments  12  serve as a thermal barrier and to shield the base body from hot gases. For that reason, according to the exemplary embodiment shown, the segments  12  are advantageously made of ceramics or ceramic systems which are resistant to high temperatures and to thermal shock and which have particularly low thermal conductivity. They protect regions situated behind them, in particular the base body. By means of the added segments  12 , the base body is subjected to substantially lower thermal stresses and for this reason can have larger dimensions, along the represented outer edges of the heat shield tile  10 , than conventional heat shield tiles. The base body serves for the mechanical integrity and stability of the heat shield tile  10 . 
         [0075]    In addition, on account of the thermal protection function of the segments  12 , the base body can be made of materials which are optimized for their mechanical durability. Suitable for this are for example metals, monolithic ceramics, ceramic matrix composites or high-temperature refractory ceramics. 
         [0076]    According to the exemplary embodiment represented, the segments  12  are adhesively bonded to adhesive bonding regions of the base body. The adhesion between the segments  12  and the base body can be increased if corresponding structure elements in the form of roughenings, grooves, bumps or the like are introduced into the respective connection faces of the segments and of the base body. This can be effected during production of the corresponding components or also subsequently, for example by mechanical or laser machining.  FIG. 1  shows the profile of such structure elements by way of dashed lines. 
         [0077]      FIG. 2  shows the heat shield tile  10  of  FIG. 1  in a schematic sectional representation along the plane labeled II in  FIG. 1 . 
         [0078]    The heat shield tile  10  can be arranged releasably, by means of retaining elements, on a supporting structure (not shown) of a heat shield, having a cold side  1  oriented toward the supporting structure and, arranged on the opposite side, a hot side  2  which can be exposed to hot gases, and side faces  3  connecting the cold side  1  and the hot side  2 . The heat shield tile  10  has a hybrid construction with a base body  14  arranged on the cold side and the segments  12  arranged on the hot side and already represented in  FIG. 1 , wherein the thickness of the base body  14  and of the segments  12  perpendicular to the cold side, according to the exemplary embodiment shown, is essentially equal. The segments  12  are joined to the base body  14 . The connection between the segments  12  and the base body  14  is ensured by means of an adhesive layer  18 . On account of the relatively low areal extent of the individual segments  12 , it is then possible, even under the extreme operating conditions of such a heat shield tile  10 , to achieve a reliable adhesive bond. The adhesion between the segments  12  and the base body  14  can be further improved if corresponding structure elements  24  in the form of roughenings, grooves, bumps or the like are introduced into the respective connection faces  20  of the segments  12  and the adhesive bonding faces  22  of the base body  14 . The adhesive bonding faces  22  of the base body can also be termed connection faces. 
         [0079]    Although the adhesive layer  18  is shielded, by the segments  12 , from the reaction gases to which the hot side  2  is exposed, use is advantageously made of an adhesive which, in the cured state, consists essentially of inorganic components, such that the durability of the connection remains long-term even under operational loads. 
         [0080]      FIG. 3  and  FIG. 4  show alternative exemplary embodiments of a heat shield tile  10  according to the invention. The exemplary embodiments differ from the exemplary embodiment shown in  FIG. 1  in terms of the shape of the segments  12 . The dashed lines in  FIG. 3  correspond to an alternative profile of structure elements (position  24  in  FIG. 2 ) which are introduced into the connection faces of the segments  12  and of the base body  14 . 
         [0081]      FIG. 5  shows a further alternative embodiment of a segment  12 , in which there is embedded a reinforcing element  26 . 
         [0082]    If particularly high demands are placed on the durability of the connection between the segment  12  and the base body  14 , and loss of individual segments  12  in the event of localized failure of the adhesive layer  18  cannot be tolerated, it is possible, as shown in  FIGS. 5 to 18 , for the segments  12  to be additionally secured by means of mechanical reinforcing elements  26 . 
         [0083]    The reinforcing element  26  shown in  FIG. 5  is held with a head region  28  in a corresponding cutout  30  of the segment  12  and partially projects out of the connection face  20  of the segment  12  with a shank  32 . An annular slot  36  surrounds the end region of the shank  32 . 
         [0084]      FIG. 6  shows an excerpt of the base body  14  according to an alternative exemplary embodiment. A cutout  34  runs through the base body, extending through the base body  14  from an adhesive bonding face  22  to the cold side  1 . The cutout  34  is formed complementarily to the shank  32  of the reinforcing element  26  represented in  FIG. 5 . 
         [0085]      FIG. 7  shows the segment  12  represented in  FIG. 5 , attached to the base body  14  represented in  FIG. 6 . For the purpose of attaching the segment  12 , an adhesive layer  18  is arranged between the connection face  20  and the adhesive bonding face  22 . The shank  32  of the reinforcing element  26  is arranged in the cutout  34  and extends essentially as far as the cold side  1 . The shank  32  of the reinforcing element  26  is releasably attached in the cutout  34  by means of a metal securing ring  38  which is inserted into the annular slot  36 . 
         [0086]    In the assembled state of the heat shield tile  10 , the securing ring  38  clamps the shank  32  of the reinforcing element  26  to the base body  14  and, in addition to the adhesive layer  18 , provides an additional mechanical connection between the segment  12  and the base body  14 . Here, too, the adhesion of the adhesive layer  18  can be improved by means of structure elements  24 , as shown in  FIG. 8 . 
         [0087]    In addition to this exemplary embodiment of a heat shield tile  10  according to the invention, as shown in  FIGS. 5 to 8 , other shapes for the reinforcing element  26  are also conceivable. Two of these are represented in  FIGS. 9 and 11 . In that context, the reinforcing elements  26  shown in  FIG. 9  have two head regions  28  and connect the segments  12  and the base body  14  by means of a form fit. 
         [0088]    The embodiment of the reinforcing element  26  shown in  FIG. 10  corresponds, in terms of shape, to that of  FIGS. 5 to 8 , wherein the shank  32  of the reinforcing element  26  is secured in the base body  14  by means of an additional adhesive layer  18  along the cutout  34 . Such an additional adhesive layer  18  in the cutout  34  is also provided in the embodiment of  FIG. 11 , wherein the metal securing ring  38  is dispensed with and the cutouts  34  in the base body  14  take the form of blind holes. 
         [0089]    As shown in  FIG. 12 , it is also possible for the segments  12  to be secured to one another by means of further reinforcing elements  40 . As is the case for the reinforcing elements  26 , these can be arranged in the segments  12  by form fitting or by adhesive bonding. 
         [0090]    The reinforcing elements  26  and  40  can of course also be used simultaneously.  FIGS. 13 to 15  show alternative embodiments of the heat shield tile  10  according to the invention, in plan view of the hot side. The exemplary embodiments show different shapes of the segments  12  and different arrangements of the reinforcing elements  26  and  40 . Since the reinforcing elements  26  and  40  are arranged inside the heat shield tiles  10 , their position is shown in  FIGS. 13 to 15  with dashed lines. 
         [0091]    As shown in  FIGS. 16 to 18 , the shank  34  of the reinforcing elements  26  can extend beyond the cold side of the base body  14  and can be used on that side of the base body  14  to anchor additional securing elements  44 . These can for example be formed of metal and provide the heat shield tile  10  with additional mechanical stability. 
         [0092]      FIG. 19  shows a schematic sectional view of a gas turbine  101  according to the prior art. In the interior, the gas turbine  101  has a rotor  103  with a shaft  104  which is mounted such that it can rotate about an axis of rotation  102  and is also referred to as the turbine rotor. An intake housing  106 , a compressor  108 , a combustion system  109  having a number of combustion chambers  110 , a turbine  114  and an exhaust gas casing  115  follow one another along the rotor  103 . The combustion chambers  110  each comprise a burner arrangement  111  and a casing  112  which, for protection from hot gases, is lined with a heat shield  120 . 
         [0093]    The combustion system  109  corresponds to a, for example, annular hot gas duct. There, multiple series-connected turbine stages form the turbine  114 . Each turbine stage is formed from blade rings. As seen in the direction of flow of a working medium, in the hot duct a row of guide vanes  117  is followed by a row of rotor blades  118 . In that context, the guide vanes  117  are secured to an inner casing of a stator  119 , whereas the rotor blades  118  of a row are fitted to the rotor  103  for example by means of a turbine disk. A generator (not shown) is for example coupled to the rotor  103 . 
         [0094]    While the gas turbine  101  is in operation, the compressor  108  sucks in air through the intake housing  106  and compresses it. The compressed air provided at the turbine-side end of the compressor  108  is passed to the combustion system  109 , where it is mixed with a fuel in the region of the burner arrangement  111 . The mixture is then combusted in the combustion system  109  with the aid of the burner arrangement  111 , forming a working gas stream. From there, the working gas stream flows along the hot gas duct past the guide vanes  117  and the rotor blades  118 . The working gas stream expands at the rotor blades  118 , imparting its momentum, so that the rotor blades  118  drive the rotor  103  and the latter drives the generator (not shown) coupled to it.