Seal for use in a heat shield element

Abstract

The invention relates to a seal (11) for use in a heat shield element (01). The seal (11) extends along a longitudinal direction and has a groove face (13) on the hot side (03) and an abutment face (14) on the cold side (04) and side faces (19) opposite one another extending from the groove face (13) to the abutment face (14) and is arranged in a sealing groove (05) of the heat shield element (01) here. In order to be able to achieve targeted cooling, a plurality of clearances (12) spaced apart from one another are provided in the seal (11), which clearances (12) extend sectionally along the longitudinal direction from the abutment face (14) towards the hot side (03).

Description

Technical Field

[0001] The present invention relates to a seal for use in a heat shielding element in a combustion chamber, by means of which uncontrolled flow of cooling air should be prevented. Background Technology

[0002] Heat shielding elements are commonly used in combustion chambers, especially in gas turbines. These elements are known to be made not only of ceramic materials but also of metallic materials. The purpose, in particular, is to provide the inner side of the combustion chamber with the most robust yet replaceable components possible. To ensure the longest possible service life, cooling of the heat shielding elements is typically achieved using cooling air. This cooling air is then delivered to the underside of the heat shielding elements, where uncontrolled flow between the elements must be prevented from entering the combustion chamber.

[0003] For this purpose, in some embodiments a seal is used, which is inserted into a groove on a surrounding connecting piece on the underside of the heat shield element. The seal typically has a rectangular cross-section and extends substantially along the length or width of the heat shield element. Here, for sealing purposes, the seal is positioned on a supporting structure, thereby causing a seal.

[0004] While known seals can provide a generally adequate and reliable seal for the purpose of the heat shielding elements on the load-bearing structure, a drawback has been shown: the required flow of cooling air is sometimes reduced too much. Furthermore, it has proven disadvantageous that the gap between two adjacent heat shielding elements is not supplied with sufficient cooling air.

[0005] A simple solution here is to partially or completely eliminate the seals and improve the fit between the heat shield and the load-bearing structure. Reducing the gap or ensuring a better fit of the heat shield on the load-bearing structure decreases flow while achieving adequate cooling. Thermal deformation under different operating conditions is problematic, causing flow to be sometimes too high or too low.

[0006] To address the aforementioned problem, it is known from the prior art to use a seal, and here holes are introduced in the connecting piece surrounding the heat shield element to ensure that cooling air flows specifically into the gap.

[0007] While proven implementations of heat-shielding elements with seals already exist, the aim is to develop a more cost-effective implementation. Summary of the Invention

[0008] The objective is achieved by a seal according to the invention as described in claim 1. Claim 10 describes a heat-shielding element with a seal according to the invention, and claim 11 describes a heat-shielding element according to the invention. Advantageous embodiments are the subject of the dependent claims.

[0009] This type of seal is first used in heat shielding elements. Here, the heat shielding element has a hot side oriented towards the interior of the combustion chamber and an opposing cold side oriented towards the supporting structure of the combustion chamber. The heat shielding element also has a sealing groove extending in the longitudinal direction. Whether the longitudinal direction coincides with the longitudinal axis of the combustion chamber or extends laterally relative to it is not important. The seal is inserted into the sealing groove at least as specified, and correspondingly extends along the longitudinal direction, thus also having a hot side and an opposing cold side. The surface of the seal on the hot side is referred to hereinafter as the groove surface. A contact surface exists on the opposing cold side. In the direction from the cold side to the hot side, the opposing side extends from the contact surface to the groove surface.

[0010] If the supporting structure and the placed heat-shielding element are substantially flat, the seal can sometimes be omitted in a simple manner without the need for a costly solution. Therefore, the present invention can be used meaningfully if the groove surface and the opposite mating surface are arched.

[0011] The seal also has a seal length extending from one end to the opposite end. The spacing between the opposite sides forms the seal width. The spacing from the groove surface to the mating surface defines the seal height according to the corresponding position along the seal length.

[0012] For seals, the rated height is defined as the nominal distance from the groove surface to the mating surface. It is desirable that the seal height correspond to the rated height as closely as possible. It is considered appropriate if the seal height deviates from the rated height by no more than 10% over at least 80% of the seal length.

[0013] Cost savings are achieved according to the present invention by providing a void in the seal. The void is provided on the cold side and extends longitudinally. Here, the void enters the seal from the contact surface toward the hot side. Correspondingly, the void represents material removal from a conventional sealing profile between the two sides. To ensure the necessary cooling airflow through the void, it is also proposed that multiple spaced-apart voids be provided on the cold side.

[0014] Due to the gap, the seal can no longer be placed on the load-bearing structure along the full length of the seal. However, what remains constant is that the surface that would exist without the gap (i.e., the entire theoretical surface on the cold side along the entire length of the seal) is understood as the contact surface.

[0015] To achieve the desired effect with the void, it is necessary that the void extends longitudinally for at least 0.1 times the length of the seal. This void is considered when its individual lengths are added together. However, the void should not be chosen to be too long, such that it extends for a maximum of 40% of the total length of the seal.

[0016] By creating a partially unsealed seal through the opening, the necessity of introducing an orifice into the heat shield element is eliminated. Currently, it is possible to have the seal formed irregularly and mismatched relative to the load-bearing structure on the cold side. However, this makes it almost impossible to predict the cooling airflow. In contrast, it is feasible to use the targeted introduction of the opening to set the desired cooling airflow.

[0017] The seal is preferably made of a metallic material. Therefore, the necessary heat resistance and durability for the intended use can be achieved in the heat-shielding element while maintaining its elastic properties.

[0018] If the seal has a constant seal width, then cost-effective manufacturing of the seal and an advantageous fit of the seal in the sealing groove are achieved. Therefore, the two sides extend parallel to each other.

[0019] If, in a top view, the sealing groove extends linearly on the cold side, it is advantageous that both sides are made flat.

[0020] Furthermore, it is advantageous that the total length of the voids extends over at least 20% of the seal length. Conversely, it is advantageous that the sum of the lengths of the voids is at most 0.3 times the length of the seal.

[0021] To achieve the desired cooling airflow through the void, it is advantageous that the void has a depth of at least 0.05 times the height of the seal, measured from the contact surface, at the same location. Particularly advantageous is that the depth of the void is at least 10% of the height of the seal.

[0022] In contrast, to ensure a true seal and its long-term stability, it is advantageous for the depth to be a maximum of 40% of the seal height. Particularly advantageous is that the depth of the clearance portion is at most 0.2 times the seal height.

[0023] Furthermore, it is equally advantageous that at at least one end section, particularly preferably at two opposing end sections, the seal height decreases toward the corresponding end. Here, at the ends of the seal, the seal height is preferably less than 50% of the nominal height. Corresponding to the contact surface on the load-bearing structure, it is also advantageous that the reduction in seal height on the hot side is caused by the groove surface correspondingly approaching the contact surface. It can be proposed that the change in seal height is stepped or caused by a ramp. However, it is advantageous to have an arcuate extension from approximately the nominal height to the reduced height at the ends of the seal.

[0024] To ensure the seal fits as accurately as possible into the sealing groove with the desired contact surface on the load-bearing structure, taking into account thermal load, it is advantageous to provide a protrusion on the hot side at at least one end section, and particularly advantageously at both end sections, spaced apart from the corresponding ends. Here, a relatively small protrusion on the hot side is sufficient to achieve a defined contact. Therefore, it is advantageous for the protrusion to have a height that is at least 0.01 times the rated height (i.e., 1% of the rated height) and at most 0.1 times the rated height (i.e., 10% of the rated height) relative to the adjacent groove surface. This allows for a targeted and thus defined placement within a uniformly shaped sealing groove, achieved by means of the protrusion.

[0025] In another embodiment, a recess is advantageously provided on the hot side at an end segment spaced apart from the end. Here, the recess has a depth of at least 5% and at most 20% of the nominal height. The recess can be used to cause the seal to be fixed in the longitudinal direction. Where a protrusion exists at the same end segment, the recess is preferably located between the end and the protrusion.

[0026] The concept of the present invention also leads to the realization of a heat shielding element according to the invention. The heat shielding element has, as described above, a hot side and an opposing cold side. Here, a sealing groove extending longitudinally and opening toward the cold side is provided. A seal is provided in the sealing groove, the seal having a groove surface on the hot side and a contact surface on the cold side.

[0027] What is required here is that the seals mounted on the heat shield element, at room temperature—before mounting on the load-bearing structure—are placed only on the bottom of the sealing groove at the two opposing end sections, wherein, in contrast, there is free space between the groove surface and the groove bottom in the region between the end sections. Thus, a defined spacing is created in the region of the end sections from the contact surface to the hot surface of the heat shield element, wherein the spacing from the contact surface to the hot surface in the region between the end sections can be adapted to the load-bearing structure due to the prescribed free space between the groove surface and the groove bottom.

[0028] According to the present invention, the sealing element of the heat shielding element has a plurality of spaced-apart gaps. Here, the gaps extend in the longitudinal direction and begin from the contact surface—similar to the previously described embodiment.

[0029] It is particularly advantageous here that the seal according to the invention is used in the embodiments described above.

[0030] At least particularly advantageously, the seal of the heat shielding element has protrusions on the hot side at two opposite end sections, and is positioned on the bottom of the sealing groove using these protrusions—and preferably only the protrusions.

[0031] As described above, the formation of the heat shield according to the invention becomes possible using the heat shielding element according to the invention. Here, the heat shield includes a support structure on which a plurality of heat shielding elements are mounted, wherein the contact surfaces of corresponding seals are disposed on the support structure. This creates a free cooling air cross-section along the length of the open portion.

[0032] Advantageously, the contact surfaces of the corresponding seals can be brought into complete contact with the load-bearing structure by means of elastic deformation of the seals when the heat-shielding element is installed. Here, the seals with contact surfaces are shaped such that, compared to the stress-free state before installation, the gap between the groove surface and the groove bottom in the region between the end segments is reduced upon installation. This advantageously ensures that the desired cooling airflow can pass through the opening without significant additional leakage.

[0033] To regulate cooling airflow, it is also advantageous that, in the installed state, a gap exists between the heat shield element (without a seal) and the supporting structure, at least in the area of ​​the opening. This ensures a free cross-section along the underside of the heat shield element through the opening. Attached Figure Description

[0034] Exemplary embodiments for seals and heat shielding elements are illustrated in the following figures.

[0035] The attached diagram shows:

[0036] Figure 1 An exemplary embodiment for a seal according to the present invention is shown;

[0037] Figure 2 An exemplary embodiment for a heat shielding element according to the present invention is shown;

[0038] Figure 3 Shown in side view according to Figure 1 Seals;

[0039] Figure 4 Shown from top view according to Figure 1 Seals;

[0040] Figure 5 A detailed view of the first end section of the seal is shown.

[0041] Figure 6 The cross-section of the heat shielding element in the area of ​​the seal is shown in detail;

[0042] Figure 7 A view showing a heat-shielding element mounted on a supporting structure, as previously shown;

[0043] Figure 8 The longitudinal section of the heat shield element in the area of ​​the seal is shown;

[0044] Figure 9 A view showing a heat-shielding element mounted on a supporting structure, as previously shown;

[0045] Figure 10 As shown in Figure 9 A view showing the thermal deformation of a heat-shielding element, similar to the one shown in the image. Detailed Implementation

[0046] exist Figure 1 A perspective view of the mating surface 14 illustrates an exemplary embodiment of the seal 11 according to the invention. Here, the seal extends longitudinally from one end to the opposite end. It can be seen that the arcuate structure is derived from the shape of the combustion chamber, thus shaping the heat shield element 01. The narrow, visible side with the arcuate shape is the mating surface 14. Laterally visible to the mating surface 14 is the flat side surface 19. However, at the two opposite end sections 15, 16, the seal height 21 decreases significantly towards the ends.

[0047] Importantly, according to an embodiment of the invention, there are a plurality of gaps 12, which also extend in sections along the longitudinal direction and here from the contact surface 14 into the seal 11.

[0048] In the following Figure 2 An exemplary heat shielding element 01 according to the invention is illustrated in a perspective view. The heat shielding element 01 is shown having a cold side 04, with a hot side 03 present, which is not visible from the opposite side. The hot side 03 here faces the interior of the combustion chamber. It can also be seen that the heat shielding element 01 has a surrounding connecting piece extending from the hot side 03 to the cold side 04. On the two opposite side edges, the connecting piece here has sealing grooves 05 extending in the longitudinal direction, respectively.

[0049] The seal 11, inserted into the sealing groove on the left side of the diagram, is also shown here. Figure 1 As shown. In the opposite sealing groove 05 on the right side of the diagram, a corresponding sealing element with a clearance portion is also provided. Alternatively, a sealing element with a clearance portion can be used in the laterally extending connecting piece.

[0050] exist Figure 3 , Figure 4 and Figure 5 The following is shown again. Figure 1 The seal in the middle: a side view on side 19— Figure 3 And a top view of the tank surface 13, i.e., from the hot side 03— Figure 4 And a detailed view of the first end section 15 of the seal 11— Figure 5 .

[0051] The seal 11 extends longitudinally and has an arcuate extension. A groove 13 is present on the hot side, which is located within a sealing groove 05 in the installed state. An opposing abutment surface 14 is present, which is positioned on the support structure 09 when the heat shield element 01 is installed. The distance from the groove 13 to the abutment surface 14 forms the seal height 21. Except for the two end sections 15 and 16, the seal height 21 is substantially constant and corresponds to the rated height of the seal 11. The two opposing sides 19 are flat, resulting in a constant seal width for the seal 01.

[0052] It can also be seen that the void 12 is provided on the cold side 04 and extends from the contact surface 14 toward the hot side 03. Here, the void 12 has a depth 22, which in the above embodiment corresponds to approximately 0.3 times the height 21 of the seal. However, it is advantageous to have an embodiment with a slightly smaller depth than shown here.

[0053] The different shapes of the end sections 15 and 16 can also be seen. Here, the distance from the groove surface 13 to the abutment surface 14 decreases towards the end, so that the height at the two opposite ends of the seal is reduced to about 0.3 times the rated height—the rated height basically corresponds to the seal height 21 in the extension between the end sections 15 and 16.

[0054] It can also be seen that on the hot side 03, there are protrusions 17 at the two end sections 15 and 16 respectively. The height of the protrusions 17 relative to the adjacent groove surface 13 is relatively low. The purpose of the protrusions 17 is to establish a defined placement on the bottom 06 of the sealing groove 05.

[0055] At the first end section 15, there are also two recesses 18 on the hot side 03. The recesses 18 enable the sealing member 11 to be fixed in the longitudinal direction on the heat shielding element 01.

[0056] exist Figure 6 and Figure 7 The image shows a detailed cross-sectional view of the heat shield element 01 and its seal 11. It can be seen that the heat shield element 01 has a connecting piece shown here, which extends from the hot side to the cold side 04 and has a sealing groove 05 on the cold side 04. The seal 11 is located in the sealing groove 05, with a void 12 on the cold side 04.

[0057] exist Figure 6 The diagram shows the stress-free installation of the seal 11 on the heat shield element 01, where a large free space exists between the groove surface 13 and the groove bottom 06 of the sealing groove 05. In contrast, in... Figure 7 The installation on the supporting structure 09 is shown in the figure, which reduces the distance between the bottom of the groove 06 and the surface of the groove 13.

[0058] It can also be seen that there is a gap 10 between the heat shield element 01 and the supporting structure 09, wherein the gap 12 can realize a free channel for cooling airflow.

[0059] to this end, Figures 8 to 10 The arrangement of the seal 11 on the heat shield element 01 is also shown in a longitudinal section, i.e., along the longitudinal direction. (See from...) Figure 8 As can be seen, the seal 11 is accommodated in the sealing groove 05. Here, the seal 11 abuts against the bottom 06 of the sealing groove 05 with two protrusions 17, which are located on the end sections 15 and 16. In contrast, there is free space between the end sections 15 and 16 between the groove surface 13 and the groove bottom 06.

[0060] By mounting the heat shield element 01 along with the seal 11 onto the load-bearing structure 09 of the combustion chamber, the seal 11 deforms as the distance from the groove surface 13 to the groove bottom 06 decreases—see Figure 9 .

[0061] If thermal deformation occurs, it is feasible to keep the heat shielding element 01 away from the supporting structure 09 at its center. However, the seal 11 is located on the supporting structure 09 with the abutment surface 11, wherein the distance from the groove surface 13 to the groove bottom 06 is increased again—see Figure 10 .

[0062] Important to this invention is the vacancy 12 in the seal 11, which ensures controlled cooling airflow as inconsequentially as possible to the deformation of the heat shield element 01.

Claims

1. A seal (11) for use in a heat shielding element (01), the seal (11) extending along a longitudinal direction along the length of the seal and having an arched groove (13) on a hot side (03), an arched abutment surface (14) on an opposite cold side (04), and opposing sides (19) extending from the groove (13) to the abutment surface (14), wherein a nominal height is given as a nominal spacing, and a seal height (21) is given as a partial spacing from the groove (13) to the abutment surface (14), wherein the seal height (21) deviates from the nominal height by no more than 10% over at least 80% of the seal length, ignoring the void (12), characterized in that, The seal is provided with a plurality of spaced-apart gaps (12), which extend in sections along the longitudinal direction from the contact surface (14) toward the heat side (03) for a total length of at least 10% and at most 40% of the seal length. The groove surface is convex and the abutment surface (14) is concave, wherein at one or both end sections (15, 16), the height (21) of the seal decreases to less than 50% of the rated height on the hot side (03) toward the corresponding end.

2. The seal (11) according to claim 1. The seal is made of metal.

3. The seal (11) according to claim 1 or 2. The side (19) therein is parallel.

4. The seal (11) according to claim 1 or 2. The void (12) extends along the longitudinal direction for a total of at least 20% and / or at most 30% of the length of the seal.

5. The seal (11) according to claim 1 or 2. The depth (22) of the void (12) is at least 5% and at most 40% of the height (21) of the seal.

6. The seal (11) according to claim 1 or 2. At one or both end segments (15, 16), a protrusion (17) is provided on the hot side (03) spaced apart from the corresponding end, the height of the protrusion (17) being at least 1% and at most 10% of the rated height.

7. The seal (11) according to claim 6. At the end section (15), at least one recess (18) is provided on the hot side (03) spaced apart from the end, the depth of the recess (18) being at least 5% and at most 20% of the nominal height.

8. The seal (11) according to claim 3. The side (19) therein is flat.

9. The seal (11) according to claim 1. The depth (22) of the void (12) is at least 10% of the height (21) of the seal.

10. The seal (11) according to claim 1. The depth (22) of the void (12) is up to 20% of the height (21) of the seal.

11. The seal (11) according to claim 7. The recess (18) is located between the end and the protrusion (17).

12. A heat shielding element (01) for use in a heat shielding member in a combustion chamber, the heat shielding element having a hot side (03) and an opposing cold side (04), the heat shielding element (01) having at least one sealing groove (05) extending in a longitudinal direction and opening toward the cold side (04), a seal (11) disposed in the sealing groove (05), the seal (11) having a groove surface (13) on the hot side (03), an abutment surface (14) on the cold side (04), and opposing parallel side surfaces (19) extending from the groove surface (13) to the abutment surface (14), wherein, at least at room temperature, the seal (11) is disposed on the groove bottom (06) of the sealing groove (05) at two opposing end sections (15, 16), and in the region between the two end sections (15, 16), there is free space between the groove bottom (06) and the groove surface (13), characterized in that, It is provided with at least one seal (11) according to any one of claims 1 to 11 above.

13. The heat shielding element (01) according to claim 12, wherein the seal (11) has a protrusion (17) spaced apart from the corresponding end on the hot side (03) at both end sections (15, 16), the protrusion having a height of at least 1% and at most 10% of the rated height, wherein at least at room temperature, the seal (11) is positioned at the bottom (06) of the sealing groove (05) at the two opposing end sections (15, 16) with the protrusion (17).

14. A heat shield for use in the combustion chamber of a gas turbine, the heat shield comprising a support structure (09) and a plurality of heat shielding elements (01), the heat shielding elements having a seal (11) according to any one of claims 1 to 11, wherein the seal (11) is disposed on the support structure (09) with the contact surface (14).

15. The heat shield according to claim 14, At least at room temperature, the seal is elastically deformable, and the distance from the bottom of the groove (06) to the surface of the groove (13) is reduced relative to the stress-free case.

16. The heat shield according to claim 14 or 15, A gap (10) is generated between the heat shielding element (01) itself and the supporting structure (09), at least in the area of ​​the void (12).

Images