EP2992270B1 - Heat shield - Google Patents

Description

The invention relates to a fastening of a heat shield brick to a support structure and to a heat shield and a combustion chamber lined by the heat shield and a gas turbine.

In many technical applications, heat shields are used which must withstand hot gases of 1000 to 1600 degrees. In particular, gas turbines, such as those used in power-generating power plants and in aircraft engines, have correspondingly large surfaces to be shielded by heat shields in the interior of the combustion chambers. Because of thermal expansion and large dimensions, the heat shield must be composed of a plurality of individual, generally ceramic heat shield bricks, spaced apart from each other with a sufficient gap to a support structure. This gap offers the heat shield bricks, which can also be called heat shield elements, sufficient space for thermal expansion.

A generic heat shield thus comprises a support structure and a number of heat shield bricks, which are attached to the support structure, in particular releasably secured, are. Each of the heat shields has a cold side facing the support structure and a hot side which is opposite the cold side and can be charged with a hot medium. In at least one heat shield brick at least one recess is arranged in at least one of the cold side with the hot side connecting peripheral side of the heat shield brick, wherein perpendicular to the cold side, the recess with the cold side connecting recess extends in the peripheral side. For fastening the heat shield brick to the support structure, a fastening bolt can be inserted into the recess, so that a bolt head of the fastening bolt at least partially protrudes into the recess. Here, the fastening bolt passes through an angle plate in a penetration area. The angle sheet comprises a first leg extending substantially parallel to the peripheral side and a second leg extending into the recess. The two legs adjoin one another at an angle edge. Such attachment of the heat shield brick, in particular with two recesses each on two opposite circumferential sides, is particularly well suited for fastening a closing stone of a row of heat shield bricks circumferentially arranged on the combustion chamber wall. The graduation stones are also called dummy stones.

The EP 1 884 713 B1 discloses a generic heat shield in which the heat shield bricks are mounted in rows arranged coaxially to a combustion chamber longitudinal axis on the support structure. The heat shield bricks of a row are held by holding elements, which are inserted into a mounting groove extending in the support structure, wherein the holding elements of the subsequent heat shield bricks are inserted after attachment of the retaining elements of the previous heat shield brick in the mounting groove and block the previous ones. In the known heat shield the dummy stones are fixed by means of a screwed into the support structure attachment to the support structure. These dummy stones have two recesses on two opposite, the cold side with the hot side connecting peripheral sides of the heat shield brick. For each of these recesses is perpendicular to the cold side, a recess connecting to the cold side recess in the peripheral side. For fixing the dummy stone to the support structure, a fastening bolt is inserted into each of the four recesses, so that a bolt head of the fastening bolt protrudes into the recess. So that the pressure acting on the heat shield brick by the bolt head is better distributed, an angle sheet is arranged below the bolt head. The fastening bolt passes through the angle plate in a penetration area, so that the angle plate with a protruding into the recess leg extends below the bolt head and covers with a substantially parallel to the peripheral side extending leg, the recess in which the fastening bolt extends. Slipping out of the fastening bolt from the recess can lead to a loss of the heat shield brick. This can cause damage to the lined with the heat shield combustion chamber during operation.

The invention has for its object to provide a heat shield with at least one heat shield brick of the type mentioned, the attachment avoids a detachment of the heat shield brick from the support structure particularly safe.

For this purpose, the angle plate comprises an over the pure angle shape beyond reinforcing device. The reinforcing means increases the resistance of the angle plate against bending caused by the fastening bolt.

The invention is based on the finding that the generic attachment of the heat shield brick can be significantly improved by design of the angle plate in their reliability. A transformation of the fastening bolt, the recess, the amount of cooling air or the entire fastening concept is therefore not required.

The invention ensures the attachment of the heat shield brick by means of an amplifying device on the angle plate.
This prevents a displacement of the angle plate, which may result in slipping out of the fastening bolt from the recess.

According to the invention, the reinforcement means does not consist of a material change of the angle sheet or a uniform reinforcement of the thickness of the angle sheet, since such reinforcement means would not go beyond the pure angle shape.

The term angle plate is not to be understood as limiting the choice of material for the angle plate.
The term heat shield brick is not to be understood as limiting the choice of material. The heat shield block preferably consists of a ceramic material.

The heat shield bricks designed according to the invention may be isolated heat shield bricks of the heat shield. For example, only the dummy stones. But it could also be designed according to the invention, for example, all heat shield bricks of the heat shield. In this case, all heat shield bricks would be arranged on the support structure by means of at least one such fastening comprising a fastening bolt and an angle sheet. The recess may be, for example, a holding pocket arranged in the peripheral side. According to a further example, the recess could also be a retaining groove extending along the peripheral side, into which a plurality of spaced-apart recesses open, so that a plurality of fastening bolts can be arranged on this side of the heat shield block.

To explain the concept of the amplifying device according to the invention, a non-limiting number of exemplary embodiments is given below, which can also be combined with one another to form an amplifying device according to the invention. The reinforcing device may, for example, extend at least partially behind the penetration area viewed from the angle edge and stiffen this region, so that a resistance of the angle plate is increased against a bending caused by the fastening bolt. The reinforcing device can be formed in this case, for example in the form of a welded onto the second leg web. The web may, for example, extend parallel to the angular edge over the entire width of the second leg. But the web could also span, for example, arcuately the area behind the penetration area. Another embodiment the reinforcing device can provide a profiling of the angle plate, for example, a wave-shaped profiling of the second leg. According to a further embodiment of the reinforcing device, the reinforcing device may, for example, also extend below the bolt head.

It can advantageously be provided that at least one surface of the amplifying device laterally at least partially reflects cooling air exiting the bolt head.

During the exposure of the heat shield brick with hot gas, for example, cooling air is passed through the fastening bolt. The cooling air flows through a cooling air duct extending in the fastening bolt, which comprises at least one cooling air opening laterally on the bolt head, so that cooling air exits laterally on the bolt head. According to a further embodiment, the cooling air can be guided laterally of the fastening bolt shaft along the recess, so that the cooling air emerges laterally at the bolt head in the region of the penetration area.

The embodiment increases a residence time of the cooling air in the region of the angle plate, so that it is better cooled during operation. The cooling air can impinge directly on the surface or redirect already reflected cooling air. The inventive design of the invention increases due to the improved cooling of the angle plate whose dimensional stability, so that the angle plate has an increased resistance to a bending caused by the fastening bolt.

The surface may be, for example, a side surface of a wave-shaped profiling of the second leg facing the bolt head. This embodiment of the amplification device combines two advantages. The angle plate is reinforced due to the profiling in a mechanical manner against bending and simultaneously is provided in an inventive manner for increased cooling of the angle plate. The surface may also be the side surface facing the bolt head of the first side wall described in more detail below, the angled side wall or the shielding side wall of the reinforcement device.

It may also be considered advantageous that the reinforcing device comprises a first side wall which is arranged in the region of the inlet opening of the recess such that the first side wall at least partially closes the inlet opening of the recess.

This embodiment of the invention enables a significantly improved cooling of the second leg, which is particularly at risk from bending of the angle plate. The cooling air exiting laterally on the bolt head of the fastening bolt remains in the region of the recess over a relatively long period of time. The first side wall may, for example, run along the angle edge and be welded to it in web-like fashion. According to a further embodiment of the embodiment of the invention, the angle plate can be realized with first side wall, for example, by two T-shaped welded together sheets. But it is also possible to arrange the first side wall in a different manner to the angle plate. For example, indirectly by means of further side walls of the amplifying device.

An advantageous embodiment of the invention may provide that the first side wall of the reinforcing device substantially completely closes the inlet opening of the recess.

In this case, the cooling effect of the reinforcing device is so good that a mechanical stability of the first side wall for increasing the resistance of the angle plate need not be considered further.

A further advantageous embodiment of the invention can provide that the first side wall is arranged at a right angle on a second side wall of the reinforcing device. The second side wall extends along the second leg and includes an opening aligned with the penetration area of the second leg.

The second side wall may for example be arranged cohesively on the second leg and holds the first side wall in the inlet opening of the recess. In other words, the angle plate is joined together to form the first side wall with a second angle plate. In this case, one leg of the second angle plate runs parallel to the second leg of the first angle plate and is arranged thereon. The first side wall is formed in this case by the other leg of the second angle plate. This embodiment further increases the dimensional stability of the angle plate by the double sheet metal layer on the second leg.

Advantageously, it can further be provided that
the fastening bolt comprises at least one cooling air duct, which opens laterally on the bolt head in at least one outlet opening, wherein in the second side wall in the region of at least one outlet opening of the cooling air duct extending to the periphery of the opening recess is arranged.

The at least one recess may be formed in the form of a groove which ends in an outlet. Due to an impingement cooling of its side walls and in particular an impingement cooling of its outlet, the recess increases the cooling effect of the cooling air conducted into the recess. This results in an impact of the heat shield brick with hot gas to improved cooling, in particular the second side wall and the second leg of the angle plate.

Furthermore, it can be advantageously provided that the reinforcing device runs at least partially and, viewed from the angle edge, behind the penetration area and stiffens this area.

This advantageous embodiment of the invention reinforces a region of the angle plate, which is designed to be particularly narrow due to the penetration region.

It can also be considered advantageous for the second leg of the angle plate or the second side wall of the reinforcing device to comprise on its side opposite the angle edge a side wall angled away from the angle edge, which extends at least partially and behind the penetration area viewed from the angle edge stiffened this area.

The angled side wall increases the fate of cooling air in the region of the angle plate and at the same time serves the mechanical reinforcement of the particularly narrow formed portion of the angle plate behind the penetration area. The embodiment of the invention can be realized, for example, in combination with a wave-shaped profiling of the angle sheet or, for example, alone form the reinforcing device. The opposite to the angle edge angled side wall can be made for example by bending over a corresponding portion of the second leg. The side wall may also be arranged in a different manner on the second leg. The angle between leg and angled side wall is preferably substantially perpendicular.

To further increase the cooling effect and thus the dimensional stability of the angle plate, it can be advantageously provided that on the angled side wall at a distance height, a shielding side wall is arranged, which extends in the direction of the inlet opening of the recess.

The shielding side wall preferably runs substantially parallel to the second leg.

The shielding side wall may extend, for example, to the entrance area of the recess. Depending on the distance height, the shielding side wall can comprise a recess for the bolt head or at least one opening for an assembly tool. The embodiment of the invention has several advantages. The shielding side wall shields the second leg against hot gas intake. Also, a limited by the angled side wall and the shielding side wall cooling air space is realized, in which laterally on the bolt head of the fastening bolt exiting cooling air is passed back to the angle plate, so that increases the residence time of the cooling air in the recess. The cooling air withdraws from the recess after some time and enters the combustion chamber through the expansion gaps between the heat shield stones. The longer the cooling air remains in the recess, the better the cooling of the angle plate. By the two side walls also a baffle cooling of the heat shield brick is avoided. The heat shield bricks are generally made of a ceramic material, which tends to crack in the direct flow of cooling air. Also, the shape of the embodiment of the invention prevents bending of the angle sheet by overheating or creeping. The angle plate according to the embodiment can also be made from a single piece by a further U-shaped bend is introduced into the sheet metal strip at the end of the second leg. According to one embodiment of the embodiment of the invention, in addition to the shielding side wall nor the first side wall can be arranged, for example by the shielding side wall is angled in the direction of angle edge in the entrance region of the recess. However, this embodiment can also be realized, for example, by an angle plate with first and second legs, on which a pipe section is arranged is, whose quadrangular cross section is perpendicular to the angular edge.

Advantageously, it can further be provided that the reinforcing device is realized at least partially by means of a profiling of the second leg.

Under profiling of the second leg are here to be understood by the substantially planar extent of the leg deviating formations of the leg, such as a wave-shaped course of the leg material or fixed on the leg square.

Advantageously, the second leg at least partially parallel to the angular edge have a wave-shaped course.

Due to the undulating course, a reinforcement of the angle plate is made possible. The amplifying device can be realized, for example, exclusively by means of the wave-shaped course of the second leg. The wave-shaped course can in this case be designed such that at least one shaft comprises a side surface which laterally at least partially reflects cooling air flowing from the bolt head. This produces in addition to the caused by the wave-shaped profiling mechanical reinforcement of the angle plate a cooling effect on the angle plate and thus a further increase in the dimensional stability of the component. The advantageous embodiment of the invention can be made of a standard component, which is impressed on a wave-shaped course. This reduces the manufacturing costs.

Advantageously, it can further be provided that the second leg at least partially perpendicular to the angular edge has a wave-shaped course.

This also allows the realization of the invention with low production costs. The wave-shaped course may, for example, extend over the entire width of the second leg. Thus, the profiling runs partially behind the penetration area, viewed from the angle edge, and stiffens this area.

Advantageously, it can further be provided that the wave-shaped course is sinusoidal, with the wave-shaped course passing through the sine function substantially from 0 to 2π.

The formation of a wave crest and a wave trough are already sufficient to allow a sufficient reinforcement of the angle plate. This simplifies the production of the angle sheet.

A further advantageous embodiment of the invention can provide that two such recesses are arranged on the heat shield brick on two opposite peripheral sides, so that the heat shield brick can be fastened to the support structure by means of four fastening bolts arranged in pairs opposite one another.

This attachment allows a particularly stable arrangement of the heat shield brick on the support structure.

It can also be considered advantageous that the fastening bolt can be detachably fastened to the support structure by means of a disk spring packet arranged in the support structure.

Advantageously, it may further be provided that a hole aligned with the fastening bolt extends from the hot side to the recess through the heat shield brick.

This allows easy access for a bolt head assembly tool.

It can also be considered advantageous that
the reinforcing device of the angle plate in the penetration region comprises a reinforcing body arranged between the first and second legs and projecting into the recess, which is arranged with a side surface on the first leg and with an upper side on the second leg, wherein the reinforcing body has a through hole for the fastening bolt in that the fastening bolt with a shank of the fastening bolt passes through the penetration area and the reinforcing body.

The fastening bolt is thus inserted with its bolt shank through the penetration region of the second leg and the reinforcing body into the angle plate, so that the bolt head rests on the second leg and the shaft protrudes through the second leg and through the reinforcing body. The angle plate is positioned together with the bolt on the peripheral surface of the heat shield brick with the second leg and the bolt head in the recess and the reinforcing body and extending through the reinforcing body bolt shank in the recess.

Advantageously, it can be provided that
the reinforcing body has a substantially semicircular upper side parallel to the second leg, wherein the straight side of the semicircle rests against the first leg.

The reinforcing body can thus have a semicircular cross-section parallel to the second leg.

Alternatively it can be provided that
the upper side of the reinforcing body resting against the second limb essentially has the shape of a triangle with a rounded tip, wherein the tip is rounded substantially in correspondence with the throughbore and the base side of the triangle adjoins the first limb.

The reinforcing body may have over its entire height (perpendicular to the second leg) has a cross section corresponding to the triangular top.

However, the reinforcing body can also have a lower height at the tip than at the base side, so that the shape of the reinforcing body substantially corresponds to a straight prism having the rounded triangular shape as a base, wherein the side opposite the top side is not arranged parallel to the top. The prism is thus formed opposite the top chamfered. As a result, the side regions of the reinforcing body extending perpendicular to the second leg act as reinforcing ribs.

It can also be considered advantageous if
the angle plate is formed with the reinforcing device as a one-piece casting.

In particular, this makes it possible to produce the angle plate together with the reinforcing body as a one-piece casting.

The material of the casting may for example consist of Nimonic 90.

By means of casting methods, in particular in so-called tree casting, a number of such angle plates with reinforcing means can be produced simultaneously. This reduces the manufacturing costs.

A further object of the invention is to specify a combustion chamber lined with a heat shield mentioned at the outset and a gas turbine having such a combustion chamber which makes it possible to fasten a heat shield brick which particularly reliably avoids detachment of the heat shield brick from the support structure.

The object is achieved in a combustion chamber of the type mentioned above in that the heat shield is designed according to one of claims 1 to 21.

The object is achieved in a gas turbine of the type mentioned in that at least one combustion chamber is formed according to claim 22.

Further expedient refinements and advantages of the invention are the subject matter of the description of embodiments of the invention with reference to the figure of the drawing, wherein like reference numerals refer to the same acting components.

• Figur 1 eine erfindungsgemäße Gasturbine mit einer von einem Hitzeschild ausgekleideten Brennkammer in einer schematischen Schnittansicht,
• Figur2 schematisch einen Ausschnitt eines Hitzeschildes im Querschnitt nach dem Stand der Technik,
• Figur 3 eine Einzeldarstellung eines Befestigungsbolzens mit einem Winkelblech gemäß einem ersten Ausführungsbeispiel der Erfindung in einer perspektivischen Ansicht und schematischer Darstellung,
• Figur 4 den in Figur 3 dargestellten Befestigungsbolzen mit Winkelblech in einer Draufsicht,
• Figur 5 eine Einzeldarstellung eines Befestigungsbolzens mit einem Winkelblech gemäß einem zweiten Ausführungsbeispiel der Erfindung in einer perspektivischen Ansicht und schematischer Darstellung, und
• Figur 6 den in Figur 5 dargestellten Befestigungsbolzen mit Winkelblech in einer Draufsicht.
• Figur 7 schematisch einen Ausschnitt eines erfindungsgemäßen Hitzeschilds im Befestigungsbereich eines Hitzeschildsteines mit einem Winkelblech gemäß einem dritten Ausführungsbeispiel der Erfindung in geschnittener Ansicht,
• Figur 8 schematisch eine Einzeldarstellung des in Figur 7 dargestellten Winkelblechs in perspektivischer Ansicht,
• Figur 9 das Winkelblech der Figur 8 in einer perspektivischen Draufsicht,
• Figur 10 einen Ausschnitt eines erfindungsgemäßen Hitzeschilds im Bereich einer Hitzeschildstein-Umfangsseite mit einer Aussparung und einem Winkelblech gemäß einem vierten Ausführungsbeispiel der Erfindung, und
• Figur 11 eine Einzeldarstellung des in Figur10 gezeigten Winkelblechs mit angeordnetem Befestigungsbolzen.
• Fig.12 schematisch eine perspektivische Ansicht eines erfindungsgemäßen Winkelblechs mit Verstärkungskörper gemäß einem fünften Ausführungsbeispiels,
• Fig.13 schematisch eine perspektivische Ansicht eines erfindungsgemäßen Winkelblechs mit Verstärkungskörper gemäß einem sechsten Ausführungsbeispiel,
• Fig.14 schematisch das in Fig.13 dargestellte Winkelblech in einer Seitenansicht.

Showing:

• FIG. 1 a gas turbine according to the invention with a combustion chamber lined by a heat shield in a schematic sectional view,
• Figur2 FIG. 2 schematically shows a section of a heat shield in cross section according to the prior art, FIG.
• FIG. 3 a detailed view of a fastening bolt with an angle plate according to a first embodiment of the invention in a perspective view and a schematic representation,
• FIG. 4 the in FIG. 3 illustrated fastening bolts with angle plate in a plan view,
• FIG. 5 an individual view of a fastening bolt with an angle plate according to a second embodiment of the invention in a perspective view and schematic representation, and
• FIG. 6 the in FIG. 5 illustrated fastening bolts with angle plate in a plan view.
• FIG. 7 1 is a sectional view of a detail of a heat shield according to the invention in the attachment region of a heat shield brick with an angle sheet according to a third exemplary embodiment of the invention;
• FIG. 8 schematically an individual representation of in FIG. 7 shown angle plate in a perspective view,
• FIG. 9 the angle sheet of FIG. 8 in a perspective plan view,
• FIG. 10 a section of a heat shield according to the invention in the region of a heat shield stone peripheral side with a recess and an angle plate according to a fourth embodiment of the invention, and
• FIG. 11 a detailed description of the in Figur10 shown angle plate with arranged fastening bolt.
• Figure 12 1 schematically a perspective view of an angle plate according to the invention with reinforcing body according to a fifth exemplary embodiment,
• Figure 13 1 schematically a perspective view of an angle plate according to the invention with reinforcing body according to a sixth embodiment,
• Figure 14 schematically the in Figure 13 shown angle plate in a side view.

The FIG. 1 schematically shows a gas turbine 1 according to the invention in a longitudinal section. This comprises a compressor section 3, a combustion chamber section 5 and a turbine section 7. A shaft 9 extends through all sections of the gas turbine 1. In the compressor section 3, the shaft 9 is provided with rings of compressor blades 11 and in the turbine section 7 with rings of turbine blades 13. Wreaths of compressor guide vanes 15 are located between the rotor blade rings in the compressor section 3 and rings of turbine guide vanes 17 in the turbine section 17. The guide vanes extend from the housing 19 of the gas turbine installation 1 essentially in the radial direction to the shaft 9.

During operation of the gas turbine 1, air 23 is sucked in through an air inlet 21 of the compressor section 3 and compressed by the compressor rotor blades 11. The compressed air is supplied to a combustion chamber 25 arranged in the combustion chamber 25, which is configured in the present embodiment as a lined with a heat shield 2 annular combustion chamber, in which a gaseous or liquid fuel via at least one burner 27 is injected. The resulting air-fuel mixture is ignited and burned in the combustion chamber 25. Along the flow path 29, the hot combustion exhaust gases flow from the combustor 25 into the turbine section 7, where they expand and cool, imparting momentum to the turbine blades 13. The turbine guide vanes 17 serve as nozzles for optimizing the momentum transfer to the rotor blades 13. The rotation of the shaft 9 brought about by the momentum transfer is used to drive a load, for example an electric generator. The expanded and cooled combustion gases are finally discharged from the gas turbine 1 through an outlet 31.

The FIG. 2 shows a section of a heat shield 2 according to the prior art in cross section. Two adjoining heat shield bricks 20, 22 are attached to a support structure 28. The one heat shield block 20 is fastened with a holding element 48 on the support structure. The other heat shield brick 22 is designed as a dummy stone. For fixing the dummy stone, a peripheral side 30 of the heat shield brick 22 connecting a hot side 24 with a cold side 26 facing the support structure 28 has a recess 34, which in the illustrated example is formed as a groove running in the peripheral side 30. Perpendicular to the cold side 26, a recess 34 connects to the cold side 26 recess 32 in the peripheral side 30. For fastening the heat shield brick 22 on the support structure 28, a fastening bolt 36 is inserted into the recess 32, so that a bolt head 38 of the mounting bolt 36 in the Recess protrudes. The fastening bolt 36 in this case passes through an angle plate 40 in a penetration area, the angle plate comprising a first leg 40a extending substantially parallel to the peripheral side 30 and a second leg 40b extending into the recess, the two legs 40a, 40b being at an angular edge 44 adjoin one another. The fastening bolt 36 is held in the support structure by means of a fastening device 42. The illustrated fastening device 42 comprises a cup spring package 52. Due to the angle plate 40, the pressure acting on the heat shield block 22 by the bolt head 38 is distributed more uniformly. In addition, the thermal expansion of the heat shield bricks 20, 22 is not hindered by means of the attachment with angle plate 40, retaining element 48 and a spacer 50.

The FIG. 3 shows an individual view of a fastening bolt 56 with an angle plate 58 according to a first embodiment of the invention in a perspective view and a schematic representation. The angle plate 58 has a first leg 58a, which can be arranged substantially parallel to a peripheral side of a heat shield block on the first leg 58a at an angle edge 60 adjacent the second leg 58b. The second leg 58b may protrude into a recess of a heat shield brick (not shown). The course of the angle edge 60 is illustrated by means of the arrow 62.

The fastening bolt 56 is cooled from the inside. For this purpose, the fastening bolt according to the illustrated embodiment, a cooling air duct 64, whose course in the shank of the fastening bolt 56 extends parallel to a longitudinal axis 66 of the fastening bolt. The illustrated cooling air channel 64 opens into four cooling air openings 68, which are arranged laterally on the bolt head 70. From this cooling air openings 68 flowing cooling air is illustrated by the arrows 72. The second leg 58b has an amplifying device 74, which increases the flexural rigidity of the angle plate 58. The amplifying device 74 is formed in the illustrated embodiment by means of a wave-shaped course of the region 58b. For this purpose, the reinforcing device 74 has parallel to the angular edge 60 a extending over the entire width 78 of the angle plate longitudinal extent. Thus, the second leg comprises a profiling which extends at least partially behind the penetration area, as viewed from the angular edge, and stiffens this area, so that a resistance of the angle plate to a deflection caused by the fastening bolt is increased. The reinforcing device 74 also has a surface 80 which partially reflects cooling air 72 discharging laterally on the bolt head 70. A penetrating area penetrated by the fastening bolt 56 is identified by reference numeral 82.

The FIG. 4 shows the in FIG. 3 shown fastening bolts 56 with angle plate 58 in a plan view. The fastening bolt 56 passes through the angle plate 58 in the region of a penetration area 82 arranged in the leg 58b. The longitudinal extent of the reinforcement 74 extends over the entire width 78 of the angle plate 58.

The cooling air 72 emerging from the cooling air openings 68 is at least partially reflected by the surface 80 of the amplifying device 74.

The FIG. 5 shows a single representation of a fastening bolt 56 with an angle plate 84 according to a second embodiment of the invention in a perspective view and in a schematic representation. The configuration of the fastening bolt corresponds to the embodiment of in FIG. 3 For this reason, the reference numerals indicated with respect to the fastening bolt 56 are the same as in FIG FIG. 3 , The angle plate 84 differs from the angle plate 58 of the FIG. 3 in that the amplification device 86 is realized in another way. For this purpose, the angle plate 84 comprises at the opposite side of the angular edge of its second leg 84b opposite to the angular edge 60 angled side wall 88. The side wall 88 extends from the angle edge seen partially behind the penetration region 92 and stiffened this area behind the penetration region 92. In this second Embodiment, the reinforcing means 86 is realized by means of the side wall 88, wherein the side wall 88 comprises a surface 90 which at least partially reflects cooling air 72 flowing laterally from the bolt head 70.

The FIG. 6 shows the in FIG. 5 shown fastening bolts 56 with angle plate 84 in a plan view. The fastening bolt 56 passes through the second leg 84b of the angle plate 84 in a penetration region 92. The longitudinal extension of the reinforcement device 88 extends over the entire width of the second leg 84b. The cooling air 72 emerging from the cooling air openings 68 is at least partially reflected by the surface 90 of the amplifying device 88.

The FIG. 7 shows a section of a heat shield according to the invention in the region of a heat shield brick 22. The heat shield stone 22 has a hot side (not shown) and a cold side 26 facing the support structure 28 and a peripheral side 30 connecting the hot side to the cold side 26 with a recess 34. In the peripheral side 30, a recess 32 connects the recess with the cold side perpendicular to the cold side 26 In order to fasten the heat shield brick 22, a fastening bolt 56 is inserted into the recess 32 so that a bolt head 70 of the fastening bolt 56 protrudes into the recess 34. The fastening bolt 56 passes through an angle plate 96 with a first leg 96a and a second leg 96b projecting into the recess, the two legs adjoining one another at an angle edge 60. The angle edge 60 is in the present embodiment, a rounded transition region between the first and the second leg. The angle plate 96 comprises an amplification device 98 according to a third exemplary embodiment of the invention with a first side wall 98a, which is arranged in the region of the inlet opening 100 of the recess 34 and substantially closes it. The first side wall 98a is disposed substantially perpendicular to a second side wall 98b of the reinforcing device 98. Here, the second side wall 98b extends along the second leg 96b and has an opening aligned with the penetration area of the second leg 96b. The opening may be formed so that the bolt head 70 rests on the second side wall 98b. In the illustrated example, the opening is formed such that the bolt head 70 extends through the opening and rests on the second leg 96b. As a result, the fastening bolt head 70 is arranged lowered in the second side wall 98b.

The fastening bolt 56 comprises in its interior a cooling air duct 64, which opens into laterally arranged on the bolt head 70 outlet openings. The cooling air flowing out laterally on the bolt head 70 is held in the recess 34 due to the first side wall 98a and retracts with a time delay, for example, through the mounting opening 102. The Reinforcing device 98 leads to a substantially improved cooling of the angle plate 96, so that a dimensional stability of the reinforcing device 98 comprehensive angle plate 96 is increased. The angle plate 96 comprising the reinforcement device 98 has an increased resistance to a force pointing in the direction of the support structure 28, which the fastening bolt 56 exerts on the angle plate.

The FIG. 8 shows that in FIG. 7 illustrated angle plate 96 with the encompassed by the angle plate 96 reinforcing device 98 in a perspective detailed view. The angle plate 96 includes a first leg 96 a and a second leg 96 b, which adjoin one another at an angle edge 60. The reinforcing device 98 comprises a first side wall 98a and a second side wall 98b, which likewise adjoin one another in the region of an angular edge, this angle edge extending parallel to the angular edge 60. The second side wall 98b is disposed on the second leg 96b and has an opening 106, which is aligned with the penetration area 104 of the second leg and whose diameter corresponds approximately to the diameter of the bolt head (not shown). At the periphery of the opening 106 recesses 108 are arranged. The recesses 108 have according to the illustrated embodiment, the shape of grooves with a semicircular end face in the end. The height of the grooves may extend over the entire thickness of the second side wall 98b, for example.

The FIG. 9 shows that in FIG. 8 illustrated angle plate 96 in a perspective top view and with a through the opening 106 and the penetration region 104 extending fastening bolt 56. The fastening bolt 56 includes according to the illustrated embodiment, a cooling air passage (not shown) which opens laterally on the bolt head 70 in at least one outlet opening 68, wherein in the second side wall 98b in the region of at least one outlet opening 68 of the cooling air channel 56, a recess 108 extending to the periphery of the opening 106 is arranged. From the outlet openings 68 exiting cooling air is shown schematically by arrows 72. The recess 108 increases due to an impingement cooling their side walls and in particular an impingement cooling their outlet, the cooling effect of the guided into the recess cooling air 72. This leads to a further improvement of the cooling, in particular the second side wall 98b and the second leg upon exposure of the heat shield brick with hot gas 96a of the angle plate 96.

The FIG. 10 shows a section of a heat shield according to the invention in perspective view of a heat shield stone peripheral side 30 in the recess portion 34 with an angle plate 110 according to a fourth embodiment of the invention. The angle plate 110 comprises an amplifying device which extends over the entire width of the second leg 110b and, viewed from the angular edge 60, extends partially behind the penetration area 92 and stiffens this area. Similar to the one in FIGS. 5 and 6 1, the second leg 110b of the angle plate 110 has on its side opposite the angle edge 60 an opposite side wall 112 to the angle edge 60, which, viewed from the angle edge 60, extends behind the penetration area 92 and stiffens this area. In deviation to the in FIGS. 5 and 6 illustrated embodiment, a shielding side wall 114 is disposed on the angled side wall 112 at a distance height, which extends to the input opening 100 of the recess 34. The shielding sidewall 114 includes a recess for the bolt head 70.

The shielding sidewall 114 shields the second leg 110b from hot gas intake. Due to the reduced ambient temperature, this increases the dimensional stability of the angle plate 110. In addition, due to its shape, the angle plate 110 has an increased resistance of the angle plate 110 against bending caused by the fastening bolt 56. In addition, a through the angled side wall 112th and the shielding side wall 114 limited cooling air space 116 realized in which laterally on the bolt head 70 of the fastening bolt 56 exiting cooling air is passed back to the angle plate 110, so that increases the residence time of the cooling air in the recess 34.

The FIG. 11 is a single representation of the in FIG. 10 shown angle plate 110 with arranged fastening bolt 56th
At the angled side wall 112, the shielding side wall 114 is arranged in the distance height 118. This shields the second limb 110b from hot gas, wherein the hot gas is indicated schematically in a greatly simplified manner by means of the arrows 120. The limited by means of the angled side wall 112 and the shielding side wall 114 and by means of the second leg 110b cooling air space 116 serves to increase the residence time of cooling air 72. The side of the bolt head 70 exiting cooling air 72 is diverted through the side walls of the cooling air space 116 and flows back on the angle plate 110. Due to the temperature reduction caused thereby a dimensional stability of the angle plate 110 is increased.

The FIG. 12 shows an angle plate 124 with a reinforcing body 126. The angle plate comprises a first leg 124a and a second leg 124b and a penetration area for a fastening bolt. In the region of the penetration area, a reinforcing body 126 is arranged, which adjoins the second leg 124b with a semicircular top side 130 and which adjoins the first leg 124a with a side face 128. By the reinforcing body 126 extends a bore 134 for insertion of a fastening bolt. The cross-section 132 of the reinforcing body and the diameter of the bore 134 is selected such that a fastening bolt is insertable into the angle plate, rests with a bolt head on the upper side 136 of the second leg and with the bolt shank through the penetration area and the reinforcing body 126 therethrough extends. The cross section of the reinforcing body is selected such that the reinforcing body can be inserted into a recess on a side surface of a heat shield block, wherein the second leg protrudes into a recess of the side surface.

Fig. 13 shows an angle plate 140 with an alternative embodiment of the reinforcing body 142. The voltage applied to the second leg 140b top 150 of the reinforcing body 142 has substantially the shape of a triangle with a rounded tip, wherein the tip is rounded substantially corresponding to the through hole 134 and the base of the Triangle (edge of the side surface 148) adjacent to the first leg.

The reinforcing body 142 has a lower height perpendicular to the second leg 140b at the top of the triangular top surface 150 than at the base side, so that the reinforcing body 142 has substantially the shape of a prism with the top surface 150 as the base surface, the prism facing the top side is bevelled.

The Fig. 14 shows the angle plate of the Fig. 13 in a side view. In this view, the side surface 144 of the reinforcing body 142 can be seen. The region of the side surfaces 144 forms on both sides in each case a reinforcing rib. The upper side 136 of the angle plate comprises for improved support of a bolt head in the penetration area a raised support area for the bolt head. This further increases the resistance of the angle plate against bending caused by the fastening bolt.

Claims (23)

1. Heat shield (2) having a support structure (28), a number of heat shield blocks (20, 22), an angled plate (40, 58, 84, 96, 110) and a securing bolt (36, 56), wherein the heat shield blocks (20, 22) are secured to the support structure (28) and have a cold side (26) facing the support structure (28) and a hot side (24) opposite the cold side (26), and, in at least one heat shield block (22), at least one recess (34) is arranged in at least one circumferential side (30) of the heat shield block (22), said circumferential side connecting the cold side (26) to the hot side (24), wherein an aperture (32), which connects the recess (34) to the cold side (26), extends in the circumferential side (30) perpendicularly to the cold side (26), wherein the securing bolt (36, 56) can be inserted into the aperture (32) to secure the heat shield block to the support structure (28), with the result that a bolt head (38, 70) of the securing bolt (36, 56) projects at least partially into the recess (34), and, at the same time, the securing bolt (3, 56) passes through the angled plate (40, 58, 84, 96, 110) in a penetration region (82, 92, 104), wherein the angled plate (40, 58, 84, 96, 110) comprises a first limb (40a, 58a, 84a, 96a, 110a), which extends substantially parallel to the circumferential side (30), and a second limb (40b, 58b, 84b, 96b, 110b), which extends into the recess (34), wherein the two limbs adjoin each other at an angle edge (44, 60),
   characterized in that
   the angled plate (40, 58, 84, 96, 110) comprises a reinforcing device (74, 86, 98) which goes beyond the pure angular shape, with the result that a resistance of the angled plate (58, 84, 96, 110) to bending caused by the securing bolt (36, 58) is increased.
2. Heat shield (2) according to Claim 1,
   characterized in that at least one surface (80, 90) of the reinforcing device (74, 86) at least partially reflects cooling air (72) emerging at the side of the bolt head (38, 70).
3. Heat shield according to Claim 1 or 2,
   characterized by
   a first side wall (98a), which is comprised by the reinforcing device (98) and at least partially closes the recess (34) in the region of the inlet opening (100) thereof.
4. Heat shield according to Claim 3,
   characterized in that
   the first side wall (98a) closes the inlet opening (100) of the recess (34) substantially completely.
5. Heat shield according to either of Claims 3 and 4,
   characterized in that
   the first side wall (98a) is arranged substantially at right angles on a second side wall (98b) of the reinforcing device (98), wherein the second side wall (98b) extends along the second limb (96b) and the second side wall comprises an opening (106) in alignment with the penetration region (104) of the second limb.
6. Heat shield according to Claim 5,
   characterized in that
   the securing bolt (36, 56) comprises at least one cooling air duct (64), which opens at the side of the bolt head (70) in at least one outlet opening (68), wherein an aperture (108) extending as far as the circumference of the opening (106) is arranged in the second side wall (98b) in the region of at least one outlet opening (68) of the cooling air duct (64).
7. Heat shield according to one of the preceding claims,
   
   characterized in that
   the reinforcing device (74, 86, 98) extends at least partially behind the penetration region (82, 92, 104), as seen from the angle edge (60), and reinforces this region.
8. Heat shield (2) according to Claim 7,
   characterized in that
   the second limb (58b, 84b, 96b, 110b) of the angled plate (40, 58, 84, 96, 110) or the second side wall (96b) of the reinforcing device comprises, on its side opposite the angle edge, a side wall (88, 112) which is angled in the opposite direction to the angle edge (60), extends at least partially behind the penetration region (82, 92, 104), as seen from the angle edge (60), and reinforces this region.
9. Heat shield according to Claim 8,
   characterized in that
   a shielding side wall (114), which extends in the direction of the inlet opening (100) of the recess (34), is arranged on the angled side wall (112) with a vertical clearance (118).
10. Heat shield (2) according to one of the preceding claims,
    characterized in that
    the reinforcing device (74, 86, 98) is implemented at least partially by means of profiling of the second limb (58b, 84b).
11. Heat shield (2) according to Claim 10,
    characterized in that
    the second limb (58b, 84b, 98b, 110b) has an undulating profile at least partially parallel to the angle edge (44, 60).
12. Heat shield (2) according to Claim 10,
    characterized in that the second limb (58b, 84b, 98b, 110b) has an undulating profile at least partially perpendicularly to the angle edge (44, 60).
13. Heat shield (2) according to Claim 11 or 12,
    characterized in that the undulating profile is sinusoidal, wherein the undulating profile traverses the sine function substantially from 0 to 2π.
14. Heat shield (2) according to one of the preceding claims,
    characterized in that
    two such recesses (34) are arranged on each of two opposite circumferential sides (30) of the heat shield block (22), thus allowing the heat shield block (20, 22) to be secured to the support structure (28) by means of four securing bolts (36, 56) arranged in opposite pairs.
15. Heat shield (2) according to one of the preceding claims,
    characterized in that
    the securing bolt (36, 56) is secured releasably to the support structure (28) by means of a diaphragm spring assembly (52) arranged on the support structure (28).
16. Heat shield (2) according to one of the preceding claims,
    characterized in that
    a hole (102) in alignment with the securing bolt (36, 56) extends through the heat shield block (20, 22) from the hot side (24) to the recess (34).
17. Heat shield according to one of the preceding claims,
    characterized in that
    the reinforcing device of the angled plate comprises, in the penetration region, a reinforcing body which is arranged between the first and the second limb, projects into the aperture and is arranged by means of a lateral surface on the first limb and by means of an upper side on the second limb, wherein the reinforcing body has a through bore for the securing bolt, with the result that the securing bolt passes by means of a shank of the securing bolt through the penetration region and the reinforcing body.
18. Heat shield according to Claim 17,
    characterized in that
    the reinforcing body has a substantially semicircular upper side parallel to the second limb, wherein the straight side of the semicircle rests on the first limb.
19. Heat shield according to Claim 17,
    characterized in that
    the upper side of the reinforcing body resting on the second limb has substantially the shape of a triangle with a rounded apex, wherein the apex is rounded substantially to match the through bore, and the base of the triangle adjoins the first limb.
20. Heat shield according to Claim 19,
    characterized in that
    the height of the reinforcing body perpendicularly to the second limb is less at the apex of the triangular upper side than at the base, with the result that the reinforcing body has substantially the shape of a prism with the upper side as the base surface, wherein the prism is beveled opposite the upper side.
21. Heat shield according to one of Claims 17 to 20,
    characterized in that
    the angled plate is designed as an integral casting with the reinforcing device.
22. Combustion chamber (25) having a heat shield (2),
    characterized in that
    the heat shield (2) is designed according to one of Claims 1 to 21.
23. Gas turbine (1) having at least one combustion chamber (25),
    characterized in that
    at least one combustion chamber (25) is designed according to Claim 22.

Images