A heat shield for a combustion chamber

Abstract

The application relates to the technical field of combustion chambers, in particular to a heat-insulating block for a combustion chamber and a heat shield comprising the heat-insulating block. The heat-insulating block has a cold surface and a hot surface oppositely arranged along the thickness direction and two side surfaces connected with the cold surface and the hot surface and extending along the longitudinal direction and oppositely arranged along the transverse direction, grooves are arranged on the two side surfaces to form side edge portions with reduced thickness, a crack guiding structure is arranged on at least one side edge portion, the crack guiding structure makes the side edge portion form a thick portion and a thin portion which are adjacent to each other along the longitudinal direction, the thickness of the thick portion is greater than that of the thin portion, the intersection position of the thick portion and the thin portion is a crack generation area, the central position of the side edge portion without the crack guiding structure along the longitudinal direction is the crack generation area, and the crack generation areas on the two side edge portions are arranged in a staggered mode along the longitudinal direction. Thus, the cracks grown from the crack generation areas to the transverse central area of the heat-insulating block along the transverse direction of the heat-insulating block are staggered with each other, so that the overall breakage of the heat-insulating block is prevented.

Description

Technical Field

[0001] This invention relates to the field of combustion chamber technology, and more particularly to a heat insulation block for a combustion chamber and a heat shield for a combustion chamber including the heat insulation block. Background Technology

[0002] The turbine inlet temperature is a crucial indicator of gas turbine technology. With advancements in gas turbine performance, combustion chamber temperatures can reach 1700K or even higher during operation, far exceeding the tolerance range of the combustion chamber shell. To ensure the safe, reliable, and stable operation of the combustion chamber, thermal insulation measures are necessary on the inner wall of the combustion chamber shell to prevent overheating. For annular and cylindrical combustion chambers, thermal insulation primarily employs a heat shield composed of ceramic insulating blocks.

[0003] During use, ceramic heat insulation blocks not only endure prolonged high-temperature corrosion and wall vibration in the combustion chamber wall, but also withstand significant thermal stress and high-temperature airflow erosion. This leads to cracks in the ceramic heat insulation blocks, which are almost entirely distributed in the central area of ​​the four sides, especially in the central area of ​​the two relatively thinner opposite sides. With prolonged service, the number and length of cracks increase. Cracks originating in the central area of ​​the opposite sides extend and converge towards the center of the heat insulation block, increasing the risk of intersecting cracks and forming through-cracks. This poses a risk of large-scale detachment of the ceramic heat insulation block, damaging the turbine. Summary of the Invention

[0004] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a heat insulation block for combustion chamber that can guide the location of crack initiation on the heat insulation block so that the cracks grow in an interlaced manner.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention provides a heat insulation block for a combustion chamber. The heat insulation block has a cold surface and a hot surface arranged opposite each other along the thickness direction, and two side surfaces that extend longitudinally and are arranged opposite each other in the transverse direction, connecting the cold surface and the hot surface. Grooves are formed on both side surfaces to form side portions with reduced thickness. A crack guiding structure is provided on at least one side portion. The crack guiding structure causes the side portion to form a thick portion and a thin portion that are adjacent in the longitudinal direction. The thickness of the thick portion is greater than the thickness of the thin portion. The junction of the thick portion and the thin portion is the crack generation area. The center of the side portion without a crack guiding structure in the longitudinal direction is the crack generation area. The crack generation areas on the two side portions are staggered in the longitudinal direction.

[0007] Preferably, the crack guiding structure is a filling portion formed by filling part of the internal space of the groove, the area of ​​the side portion with the filling portion in the thickness direction constitutes a thick portion, and the area of ​​the side portion without the filling portion in the thickness direction constitutes a thin portion.

[0008] Preferably, the filling portion and the groove are connected by a smooth transition through a curved surface.

[0009] Preferably, the length of the filling portion extending longitudinally is not less than 10 mm.

[0010] Preferably, the crack guiding structure is a groove formed on the side portion, the area of ​​the side portion with the groove in the thickness direction constitutes a thin portion, and the area of ​​the side portion without the groove in the thickness direction constitutes a thick portion.

[0011] Preferably, the groove is formed on the side edge where the side surface connects to the hot surface and / or cold surface.

[0012] Preferably, the depth of the groove along the thickness direction is no more than 10 mm, and the length of the groove along the longitudinal direction is no more than 10 mm.

[0013] Preferably, the crack guiding structure includes a filling portion formed by filling part of the interior space of the groove and a groove formed on the side.

[0014] Preferably, the opening position of the groove corresponds in the thickness direction to the longitudinal end position of the filling part located on the same side.

[0015] The present invention also provides a heat shield for a combustion chamber, comprising the heat insulation block for a combustion chamber as described above.

[0016] Compared with the prior art, the present invention has significant progress:

[0017] The combustion chamber heat insulation block of the present invention has a crack guiding structure on at least one side, such that adjacent thick and thin portions are formed on the side, and the junction of the thick and thin portions is the crack initiation region. The central portion of the longitudinal direction of the side without the crack guiding structure is the crack initiation region, and the crack initiation regions on the two sides are staggered along the longitudinal direction of the heat insulation block. Therefore, when the heat insulation block is subjected to a certain high temperature, cracks first appear in the crack initiation regions on the two sides. After cracks appear in the crack initiation regions, because the heat insulation block continues to be subjected to high temperatures, the cracks will extend and grow laterally from the crack initiation regions on the two sides towards the transverse central region of the heat insulation block. Because the crack initiation areas on the two sides are staggered along the longitudinal direction of the heat insulation block, the cracks that extend and grow from the crack initiation areas to the transverse center of the heat insulation block also intersect each other. This avoids the cracks generated on the two sides from growing and converging towards the transverse center of the heat insulation block to form through cracks, reducing the risk of the heat insulation block breaking off from the combustion chamber shell after cracking, and extending the service life of the heat insulation block in high-temperature environments. Attached Figure Description

[0018] Figure 1 This is a front view schematic diagram of the first embodiment of the heat insulation block for the combustion chamber according to Embodiment 1 of the present invention.

[0019] Figure 2 yes Figure 1 The isometric view of the insulation block is shown.

[0020] Figure 3 This is a front view schematic diagram of the second embodiment of the heat insulation block for the combustion chamber according to Embodiment 1 of the present invention.

[0021] Figure 4 yes Figure 3 The isometric view of the insulation block is shown.

[0022] Figure 5 This is a front view schematic diagram of the third embodiment of the heat insulation block for the combustion chamber according to Embodiment 1 of the present invention.

[0023] Figure 6 yes Figure 5 The isometric view of the insulation block is shown.

[0024] Figure 7 This is a front view schematic diagram of one embodiment of the heat insulation block for the combustion chamber according to Embodiment 2 of the present invention.

[0025] Figure 8 yes Figure 7 The isometric view of the insulation block is shown.

[0026] Figure 9 This is a front view schematic diagram of one embodiment of the heat insulation block for the combustion chamber according to Embodiment 3 of the present invention.

[0027] Figure 10 yes Figure 9 The isometric view of the insulation block is shown.

[0028] The reference numerals in the attached figures are explained as follows:

[0029] 1. Cold noodles

[0030] 2. Hot noodles

[0031] 3. Side view

[0032] 4. Trench

[0033] 5. Side section

[0034] 6 Crack-guided structures

[0035] 6a Filling section

[0036] 6b Groove

[0037] 7. Crack Initiation Area

[0038] 8 Adjacent side

[0039] 9. Chamfered Groove Detailed Implementation

[0040] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0041] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0044] Example 1

[0045] like Figures 1 to 6 The image shows a first embodiment of the combustion chamber heat insulation block provided by the present invention. It should be noted that, in the description of the present invention, the term "upper" is defined as... Figure 1 The top and bottom sides of the paper are Figure 1 The bottom side of the paper, in the vertical direction, is also called the "vertical" side; the "left" side is defined as... Figure 1 The left side of the paper, the "right" side is Figure 1 The right side of the paper, the left-right direction is also called "landscape"; the "front" side is defined as... Figure 1 The outer side of the paper, the "back" side is Figure 1 The inner side of the paper, in the front-to-back direction, is also called the "thickness direction".

[0046] The combustion chamber heat insulation block in this embodiment is a block with a certain thickness. The heat insulation block has a cold surface 1 and a hot surface 2 arranged opposite each other along the thickness direction. The heat insulation block has two side surfaces 3 that extend longitudinally and are arranged opposite each other in the transverse direction, connecting the cold surface 1 and the hot surface 2. The heat insulation block also has two adjacent side surfaces 8 that are adjacent to the side surfaces 3 and arranged opposite each other in the longitudinal direction. The cold surface 1, the hot surface 2, the two side surfaces 3, and the two adjacent side surfaces 8 together form a closed solid structure heat insulation block. In addition, grooves 4 are formed on both side surfaces 3 to form side edges 5 with reduced thickness. The grooves 4 extend longitudinally and penetrate the two adjacent side surfaces 8. Two chamfered grooves 9 are formed on the two side edges of each side surface 3 that are connected to the cold surface 1. The two chamfered grooves 9 on the side edge of each side surface 3 that is connected to the cold surface 1 extend longitudinally and are distributed at both ends near the longitudinal direction of the side edge. In use, the heat insulation block is suspended and fixed to the inner wall of the combustion chamber shell using accessories. One end of the accessories mates with the groove 4 and the chamfered groove 9 to fix the heat insulation block, while the other end of the accessories connects to the inner wall of the combustion chamber shell. The hot side 2 of the heat insulation block faces the interior of the combustion chamber to withstand the high-temperature hot gas, while the cold side 1 faces the inner wall of the combustion chamber shell. By installing the heat insulation block inside the combustion chamber, the heat conduction from the high temperature generated in the combustion chamber to the combustion chamber shell is reduced, preventing the combustion chamber shell from overheating.

[0047] In this embodiment, the heat insulation block has a crack guiding structure 6 on at least one side portion 5. The crack guiding structure 6 causes the side portion 5 to form a thick part and a thin part that are adjacent in the longitudinal direction. The thickness of the thick part is greater than the thickness of the thin part, so the structural strength of the thick part is greater than that of the thin part. When the heat insulation block is subjected to high temperature to a certain limit, cracks tend to germinate and grow at the location on the side portion 5 where the thickness and strength change, that is, the junction of the thick part and the thin part is the crack generation region 7. On the side portion 5 without the crack guiding structure 6, cracks tend to germinate and grow at the center of the transverse centerline of the heat insulation block on that side portion 5, that is, the longitudinal center of the side portion 5 without the crack guiding structure 6 is the crack generation region 7. When the heat insulation block is subjected to high temperature, the crack generation region 7 is more likely to generate cracks than other areas of the heat insulation block.

[0048] In this first embodiment, the crack generation areas 7 on the two side portions 5 are offset along the longitudinal direction of the insulation block. When one side portion 5 has a crack guiding structure 6 while the other side portion 5 does not, all the junctions between thick and thin portions on the side portion 5 with the crack guiding structure 6 avoid the longitudinal center of that side portion 5, thus being offset from the longitudinal center of the side portion 5 without the crack guiding structure 6 along the longitudinal direction of the insulation block. This results in the crack generation areas 7 on both side portions 5 being offset along the longitudinal direction of the insulation block. When both side portions 5 have crack guiding structures 6, all the junctions between thick and thin portions on both side portions 5 are offset along the longitudinal direction of the insulation block. This results in the crack generation areas 7 on both side portions 5 being offset along the longitudinal direction of the insulation block. In this case, there may be only one junction between a thick and thin portion on one side portion 5 located at the longitudinal center of that side portion 5. Alternatively, all junctions between thick and thin portions may avoid the longitudinal center of the side portion 5.

[0049] Therefore, when the heat insulation block withstands a certain high temperature, cracks first appear in the crack initiation areas 7 on the two side portions 5. After cracks appear in the crack initiation areas 7, because the heat insulation block continues to withstand high temperatures, the cracks will extend and grow laterally from the crack initiation areas 7 on the two side portions 5 towards the transverse center area of ​​the heat insulation block. Since the crack initiation areas 7 on the two side portions 5 are staggered along the longitudinal direction of the heat insulation block, the cracks extending laterally from the crack initiation areas 7 towards the transverse center area of ​​the heat insulation block also intersect each other. This avoids the cracks generated on the two side portions 5 from growing and converging towards the transverse center area of ​​the heat insulation block to form a through crack, reducing the risk of the heat insulation block breaking off from the combustion chamber shell after cracking, and extending the service life of the heat insulation block in high-temperature environments.

[0050] like Figure 1 and Figure 2As shown, in this embodiment, preferably, the crack guiding structure 6 is a filling part 6a formed by filling a portion of the internal space of the groove 4. The area of ​​the side portion 5 with the filling part 6a in the thickness direction constitutes a thick part, and the area of ​​the side portion 5 without the filling part 6a in the thickness direction constitutes a thin part. The filling part 6a is made of filling material, so that the part of the internal space of the groove 4 filled becomes solid. The thickness of the side portion 5 increases in the area with the filling part 6a, thus forming a thick part; in the area without the filling part 6a, the side portion 5 maintains its original thickness, thus forming a thin part. Since the thin part does not have filling material, its thickness and structural strength are lower than the thick part. Therefore, the area where the filling part 6a intersects with the groove 4 in the longitudinal direction constitutes the junction of the thick and thin parts of the side portion 5, which is the crack generation area 7. Preferably, the material used for the filling part 6a is the same as the material of the heat insulation block, reducing the risk of internal cracks caused by material differences. In addition, during the production of the insulation block, conventional pressing and casting processes are preferred to integrally form the filling part 6a with the insulation block, thereby ensuring the structural reliability of the insulation block with the filling part 6a.

[0051] When a filling part 6a is provided on one side portion 5 and not on the other side portion 5, on the side portion 5 with the filling part 6a, the areas where all the filling parts 6a intersect with the groove 4 in the longitudinal direction are all avoided from the center part in the longitudinal direction of that side portion 5. This results in a misalignment between the side portion 5 with the center part in the longitudinal direction of the insulation block and the side portion 5 without the filling part 6a, thus causing the crack generation areas 7 on both side portions 5 to be misaligned in the longitudinal direction of the insulation block. When both side portions 5 are provided with filling parts 6a... All the filling portions 6a on the two side portions 5 are staggered in the longitudinal direction at the regions where they intersect with the groove 4, so that the crack generation regions 7 on the two side portions 5 are staggered in the longitudinal direction of the insulation block. In this case, there may be only one filling portion 6a on the side portion 5 whose region intersects with the groove 4 in the longitudinal direction at the center of the longitudinal direction of the side portion 5. Of course, it is also possible that all the filling portions 6a whose regions intersect with the groove 4 in the longitudinal direction avoid the center of the longitudinal direction of the side portion 5.

[0052] A filling section 6a may be provided on a side portion 5. The filling section 6a is preferably filled in the internal space corresponding to the center part of the groove 4 in the longitudinal direction of the side portion 5, thereby increasing the strength of the center part in the longitudinal direction of the side portion 5. Alternatively, multiple filling sections 6a may be provided on a side portion 5, with a certain interval between the multiple filling sections 6a in the longitudinal direction, so that multiple thick and thin sections are formed on the side portion 5, thereby forming multiple crack generation areas 7 on the side portion 5.

[0053] Preferably, the filling part 6a is positioned between the two chamfered grooves 9 in the longitudinal direction of the heat insulation block, thereby preventing the filling part 6a from interfering with the fitting and the groove 4 and chamfered groove 9 when the heat insulation block is fixed by the fitting.

[0054] In this first embodiment, preferably, the filling part 6a and the groove 4 are connected by a smooth transition through a curved surface, so that the connection between the filling part 6a and the groove 4 forms a continuous curved surface, preventing cracks from being caused at the connection due to structural abrupt changes, and improving the overall structural strength of the heat insulation block.

[0055] In this first embodiment, preferably, the length of a single filling part 6a extending longitudinally is not less than 10 mm.

[0056] like Figure 1 and Figure 2 As shown, in the first embodiment of the combustion chamber heat insulation block of this Example 1, a filling portion 6a is provided on one side portion 5, and no filling portion 6a is provided on the other side portion 5. Preferably, the length of the filling portion 6a is 20mm to 75mm. Preferably, the filling portion 6a fills the internal space corresponding to the center of the groove 4 and the side portion 5 in the longitudinal direction, and the center of the filling portion 6a in the longitudinal direction is offset from the transverse centerline of the heat insulation block by -20mm to 20mm in the longitudinal direction.

[0057] like Figure 3 and Figure 4 As shown, in the second embodiment of the combustion chamber heat insulation block in this first embodiment, one side portion 5 is provided with multiple filling portions 6a, while the other side portion 5 is not provided with filling portions 6a. Preferably, the length of each filling portion 6a extending longitudinally is not less than 10 mm, and the longitudinal interval between adjacent filling portions 6a is not less than 10 mm. Preferably, the center of each filling portion 6a in the longitudinal direction is offset from the transverse centerline of the heat insulation block by -20 mm to 20 mm in the longitudinal direction.

[0058] like Figure 5 and Figure 6 As shown, in the third embodiment of the combustion chamber heat insulation block of this first embodiment, a filling portion 6a is provided on each of the two side portions 5. Preferably, the length of the filling portion 6a on both side portions 5 extending longitudinally is 40mm to 60mm. Preferably, the center of the filling portion 6a on both side portions 5 in the longitudinal direction is offset by 10mm to 20mm relative to the transverse centerline of the heat insulation block, and the offset directions of the filling portion 6a on the two side portions 5 are opposite.

[0059] In the fourth embodiment of the heat insulation block for the combustion chamber in this first embodiment, one side portion 5 is provided with a section of filling portion 6a, and another side portion 5 is provided with multiple sections of filling portion 6a. Preferably, the length of each section of filling portion 6a extending longitudinally is not less than 10mm, and the interval between the multiple sections of filling portion 6a on the side portion 5 is not less than 10mm.

[0060] In the fifth embodiment of the heat insulation block for the combustion chamber in this first embodiment, multiple filling sections 6a are provided on both side portions 5, and the length of each filling section 6a extending longitudinally is not less than 10mm, and the interval between the multiple filling sections 6a on each side portion 5 is not less than 10mm.

[0061] Example 2

[0062] like Figures 7 to 8 The image shows a second embodiment of the combustion chamber heat insulation block provided by the present invention. Embodiment two is basically the same as embodiment one, and the similarities will not be repeated. The difference lies in that, in this embodiment two, preferably, the crack guiding structure 6 is a groove 6b formed on the side portion 5. The area of ​​the side portion 5 without the groove 6b in the thickness direction maintains the initial thickness of the side portion 5, forming a thick portion. The area of ​​the side portion 5 with the groove 6b in the thickness direction has a reduced thickness, forming a thin portion. Therefore, the area where the area of ​​the side portion 5 with the groove 6b and the area without the groove 6b intersects in the longitudinal direction constitutes the junction of the thick and thin portions of the side portion 5, which is the crack generation area 7.

[0063] When a groove 6b is formed on one side portion 5 and not on the other side portion 5, the areas where the grooved areas 6b and the areas where the non-grooved areas 6b intersect longitudinally on the side portion 5 with the groove 6b are all offset from the longitudinal center of that side portion 5. This results in the crack-generating areas 7 on the two side portions 5 being offset longitudinally from the longitudinal center of the side portion 5 without the groove 6b. When grooves 6b are formed on both side portions 5, the areas where the grooved areas 6b intersect longitudinally on both side portions 5 are offset from the longitudinal center of that side portion 5. The areas where the groove 6b and the areas without the groove 6b intersect in the longitudinal direction are all staggered along the longitudinal direction of the insulation block, so that the crack generation areas 7 on the two side portions 5 are staggered along the longitudinal direction of the insulation block. In this case, there may be only one area on the side portion 5 where the groove 6b and the area without the groove 6b intersect in the longitudinal direction and is located at the center of the longitudinal direction of the side portion 5. Of course, it is also possible that all areas where the groove 6b and the area without the groove 6b intersect in the longitudinal direction avoid the center of the longitudinal direction of the side portion 5.

[0064] One groove 6b can be made on a side portion 5 to avoid affecting the overall structural strength of the heat insulation block; or multiple grooves 6b can be made on a side portion 5 with a certain interval between them in the longitudinal direction, so that multiple thick and thin portions are formed on the side portion 5, thereby forming multiple crack generation areas 7 on the side portion 5.

[0065] In this second embodiment, preferably, the groove 6b is formed on the side edge of the side 3 that connects to the hot surface 2 and / or the cold surface 1. That is, the groove 6b can be formed on the side edge of the side 3 that connects to the hot surface 2, or on the side edge of the side 3 that connects to the cold surface 1, or on both side edges of the side 3 that connect to the hot surface 2 and the cold surface 1 respectively.

[0066] Preferably, the depth of the groove 6b along the thickness direction is no more than 10mm, and the length of the groove 6b along the longitudinal direction is no more than 10mm, so as to avoid the thickness of the side part 5 being reduced too much, which would cause the structural strength of the heat insulation block to fail to meet the usage requirements.

[0067] like Figure 7 and Figure 8 As shown, in one embodiment of this second embodiment, preferably, a groove 6b is provided on each of the two side portions 5. The groove 6b is opened on the side edge where the side surface 3 is connected to the hot surface 2, and the grooves 6b on the two side portions 5 are respectively distributed on both sides of the transverse center line of the heat insulation block, so that the crack generation area 7 formed by the grooves 6b on the two side portions 5 is misaligned along the longitudinal direction of the heat insulation block.

[0068] Example 3

[0069] like Figures 9 to 10 The image shows a third embodiment of the combustion chamber heat insulation block provided by the present invention. Embodiment 3 is basically the same as Embodiment 1, and the similarities will not be repeated. The difference is that, in this Embodiment 3, preferably, the crack guiding structure 6 includes, in addition to the filling part 6a formed by filling part of the internal space of the groove 4 as described in Embodiment 1, a groove 6b opened on the side part 5 as described in Embodiment 2.

[0070] Preferably, a filling portion 6a and a groove 6b may be provided on one side portion 5, while the other side portion 5 may not have a filling portion 6a and a groove 6b. In this case, on the side portion 5 with the filling portion 6a and the groove 6b, the areas where all the filling portions 6a intersect with the groove 4 in the longitudinal direction, and the areas where all the areas with the groove 6b intersect with the areas without the groove 6b in the longitudinal direction, are all avoided from the longitudinal center of the side portion 5. This results in the side portion 5 being offset from the side portion 5 without the filling portion 6a and the groove 6b in the longitudinal direction along the longitudinal direction of the insulation block, so that the crack generation areas 7 on the two side portions 5 are offset from the side portion 5 in the longitudinal direction along the insulation block.

[0071] Preferably, a filling portion 6a may be provided on one side portion 5, and a groove 6b may be provided on the other side portion 5. At this time, the area where the filling part 6a on the side portion 5 with the filling part 6a intersects with the groove 4 in the longitudinal direction, and the area where the area with the groove 6b and the area without the groove 6b on the other side portion 5 with the groove 6b intersect in the longitudinal direction, are offset along the longitudinal direction of the heat insulation block. This makes the crack generation area 7 on the two side portions 5 offset along the longitudinal direction of the heat insulation block. At this time, there may be only one side portion 5 where the filling part 6a intersects with the groove 4 in the longitudinal direction and is located at the center of the longitudinal direction of the side portion 5, or there may be only one side portion 5 where the area with the groove 6b and the area without the groove 6b intersect in the longitudinal direction and is located at the center of the longitudinal direction of the side portion 5. Of course, it is also possible that all the areas where the filling part 6a intersects with the groove 4 in the longitudinal direction and all the areas where the area with the groove 6b and the area without the groove 6b intersect in the longitudinal direction avoid the center of the longitudinal direction of the side portion 5.

[0072] Preferably, filling portions 6a and grooves 6b can be provided on both side portions 5. In this case, the areas where all filling portions 6a on both side portions 5 intersect with the groove 4 in the longitudinal direction, and the areas where all areas with grooves 6b and areas without grooves 6b intersect in the longitudinal direction, are staggered along the longitudinal direction of the insulation block. This ensures that the crack generation areas 7 on the two side portions 5 are staggered along the longitudinal direction of the insulation block. In this case, only one area where a filling portion 6a on one side portion 5 intersects with the groove 4 in the longitudinal direction, or the area where an area with grooves 6b and an area without grooves 6b intersects in the longitudinal direction, can be located at the center of the longitudinal direction of that side portion 5. Alternatively, all areas where filling portions 6a intersect with the groove 4 in the longitudinal direction, and all areas where areas with grooves 6b and areas without grooves 6b intersect in the longitudinal direction, can avoid the center of the longitudinal direction of the side portion 5.

[0073] Preferably, when a side portion 5 is provided with both a filling portion 6a and a groove 6b, the opening position of the groove 6b along the thickness direction corresponds to the longitudinal end position of the filling portion 6a located on the same side portion 5. When the opening positions of all grooves 6b on a side portion 5 correspond one-to-one with the longitudinal end positions of all filling portions 6a, the location of thickness and strength variation on the side portion 5 is located in the region corresponding to the opening position of the groove 6b and the longitudinal end position of the filling portion 6a. Cracks tend to germinate and grow in the region corresponding to the opening position of the groove 6b and the longitudinal end position of the filling portion 6a, thus making the region corresponding to the opening position of the groove 6b and the longitudinal end position of the filling portion 6a the crack generation region 7; when a side portion 5 has a groove When the opening position of 6b does not correspond one-to-one with the longitudinal end positions of all filling parts 6a, the crack-inducing region 7 formed at the opening position of the groove 6b and the longitudinal end position of the filling part 6a on this side part 5 has a greater thickness and strength variation compared to the crack-inducing region 7 formed at the other grooves 6b and filling parts 6a. Therefore, cracks on this side part 5 tend to germinate and grow first in the region where the opening position of the groove 6b corresponds to the longitudinal end position of the filling part 6a, i.e., this region is used as the crack-inducing region 7 on this side part 5. When both side parts 5 are provided with filling parts 6a and grooves 6b, the regions where the opening position of the groove 6b on the two side parts 5 corresponds to the longitudinal end position of the filling part 6a are offset along the longitudinal direction of the insulation block, so that the crack-inducing region 7 on the two side parts 5 is offset along the longitudinal direction of the insulation block.

[0074] like Figure 9 and Figure 10 As shown, in one embodiment of this third example, each of the two side portions 5 is provided with a filling portion 6a and a groove 6b. The filling portion 6a fills the internal space corresponding to the center of the groove 4 in the longitudinal direction of the side portion 5. The filling portions 6a on the two side portions 5 are symmetrically arranged in the transverse direction of the heat insulation block. The grooves 6b on the two side portions 5 are respectively distributed on both sides of the transverse center line of the heat insulation block, and the groove 6b on each side portion 5 corresponds to one end position of the filling portion 6a in the longitudinal direction along the thickness direction. This means that the opening position of the groove 6b on the two side portions 5 is offset in the longitudinal direction of the heat insulation block because the area corresponding to the end position of the filling portion 6a in the longitudinal direction along the thickness direction is more likely to generate cracks than the area where the other end position of the filling portion 6a is located. This area serves as the crack generation area 7 on the side portion 5. This results in the crack generation areas 7 on the two side portions 5 being misaligned along the longitudinal direction of the insulation block.

[0075] Example 4

[0076] Based on the combustion chamber heat insulation block of the present invention, Embodiment 4 provides an embodiment of the combustion chamber heat shield of the present invention. The combustion chamber heat shield of Embodiment 4 is formed by splicing the combustion chamber heat insulation blocks of the present invention. The combustion chamber heat insulation block can be any kind of combustion chamber heat insulation block as described in Embodiments 1 to 3 above.

[0077] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A heat insulation block for a combustion chamber, the heat insulation block having a cold surface (1) and a hot surface (2) arranged opposite each other along the thickness direction, and two side surfaces (3) connecting the cold surface (1) and the hot surface (2) that extend longitudinally and are arranged opposite each other in the transverse direction, wherein grooves (4) are formed on both side surfaces (3) to form a side portion (5) with reduced thickness, characterized in that, A crack guiding structure (6) is provided on at least one of the side portions (5), the crack guiding structure (6) causes the side portion (5) to form a thick portion and a thin portion that are adjacent in the longitudinal direction, the thickness of the thick portion is greater than the thickness of the thin portion, the junction of the thick portion and the thin portion is a crack generation region (7), the center of the side portion (5) without the crack guiding structure (6) is a crack generation region (7) in the longitudinal direction, and the crack generation regions (7) on the two side portions (5) are staggered in the longitudinal direction.

2. The heat insulation block for a combustion chamber according to claim 1, characterized in that, The crack guiding structure (6) is a filling part (6a) formed by filling part of the internal space of the groove (4). The side part (5) with the filling part (6a) in the thickness direction constitutes the thick part, and the side part (5) without the filling part (6a) in the thickness direction constitutes the thin part.

3. The heat insulation block for the combustion chamber according to claim 2, characterized in that, The filling part (6a) and the groove (4) are connected by a smooth transition through a curved surface.

4. The heat insulation block for the combustion chamber according to claim 2, characterized in that, The length of the filling portion (6a) extending along the longitudinal direction is not less than 10 mm.

5. The heat insulation block for a combustion chamber according to claim 1, characterized in that, The crack guiding structure (6) is a groove (6b) formed on the side portion (5). The area of ​​the side portion (5) with the groove (6b) in the thickness direction constitutes the thin portion, and the area of ​​the side portion (5) without the groove (6b) in the thickness direction constitutes the thick portion.

6. The heat insulation block for a combustion chamber according to claim 5, characterized in that, The groove (6b) is formed on the side edge of the side surface (3) that connects with the hot surface (2) and / or the cold surface (1).

7. The heat insulation block for a combustion chamber according to claim 5, characterized in that, The groove (6b) is recessed to a depth of no more than 10 mm along the thickness direction, and the groove (6b) extends to a length of no more than 10 mm along the longitudinal direction.

8. The heat insulation block for a combustion chamber according to claim 1, characterized in that, The crack guiding structure (6) includes a filling portion (6a) formed by filling part of the internal space of the groove (4) and a groove (6b) opened on the side portion (5).

9. The heat insulation block for a combustion chamber according to claim 8, characterized in that, The opening position of the groove (6b) corresponds along the thickness direction to the end position of the filling part (6a) located on the same side part (5) in the longitudinal direction.

10. A heat shield for a combustion chamber, characterized in that, Includes the heat insulation block for combustion chamber as described in any one of claims 1 to 9.

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