CN103557536B - Ceramic heat covers sheet and heat resistant structure - Google Patents

Abstract

Propose a kind of ceramic heat herein and cover sheet, comprise the fixed part being fixed to generating surface.In use, some described ceramic heat cover sheet and are fixed to described generating surface to cover described generating surface.These ceramic heat cover sheet, and local is overlapping mutually, and the fixed part that each ceramic heat covers sheet is covered sheet covering by least one adjacent ceramic heat.

Description

Ceramic heat shield and heat-resistant structure

technical field

The invention relates to a heat shielding structure, in particular to a ceramic heat shielding sheet and a heat-resistant structure using the ceramic heat shielding sheet.

Background technique

The use of heat shielding structures on high temperature components can enhance the heat resistance of high temperature components. For example, the combustor of a gas turbine is a high temperature component. Due to the excellent heat resistance of ceramics, some manufacturers make ceramics into flakes, and then use bolts to fix them on the inner wall of the flame tube of the combustion chamber, trying to separate the high temperature in the flame tube from the wall of the flame tube. The ceramic sheets are generally square and joined together to completely cover the inner surface of the flame cylinder. Then, due to the characteristics of ceramics, the edges or sharp corners of the square ceramic sheets are prone to fracture under the action of thermal shock. Moreover, the fixed position is prone to thermal stress concentration, so it is also prone to fracture. Therefore the above-mentioned scheme proposed by the industry needs to be improved.

Contents of the invention

In view of this, this paper proposes a ceramic heat shield to improve at least one of the aforementioned problems.

A heat-resistant structure is also proposed herein to improve at least one of the aforementioned problems.

The ceramic heat shield proposed herein includes a fixing portion for fixing to a heated surface. In use, several of said ceramic heat shield sheets are fixed to said heated surface to cover said heated surface. These ceramic heat shielding sheets partially overlap each other, and the fixed portion of each ceramic heat shielding sheet is covered by at least one adjacent ceramic heat shielding sheet.

In one embodiment, the edges of the ceramic heat shielding sheet are arc-shaped. For example, the ceramic heat shield is oval.

In one embodiment, the ceramic heat shield has two opposite surfaces, and the two opposite surfaces are connected by a smooth curved surface at the edge.

In one embodiment, the fixing part of the ceramic heat shielding sheet includes a fixing hole or a buckle part.

In one embodiment, the fixing part is arranged at a position biased to the edge of the ceramic heat shield sheet.

The heat-resistant structure proposed herein includes a heated surface and several ceramic heat shield sheets covering the heated surface. The ceramic heat shields partially overlap each other. Each ceramic heat shield sheet includes a fixed portion fixed to the heated surface, and the fixed portion of each ceramic heat shield sheet is covered by at least one adjacent ceramic heat shield sheet.

In one embodiment, the fixing part is fixed to the heated surface by using a bolt or a buckle structure.

In one embodiment, each ceramic heat shield sheet includes a first end provided with the fixing portion and a second end opposite to the first end, the second end is exposed and is a free end.

In one embodiment, the edge of each ceramic heat shield is arc-shaped.

In one embodiment, each ceramic heat shield has two opposite surfaces, and the two opposite surfaces are connected by a smooth curved surface at the edge.

In one embodiment, each of the ceramic heat shield sheets has an inner surface facing the heated surface and an outer surface opposite to the inner surface, and there is a gap between the inner surface of the ceramic heat shield sheets and the heated surface .

In one embodiment, there are gaps between the ceramic heat shield sheets.

In one embodiment, the heated surface is the inner surface of the flame tube of the combustor of the gas turbine and has air holes penetrating therethrough, and the air holes are in fluid communication with the gaps and slits, so that air can pass through the air holes, gaps, and slits in sequence flow to the outer surface of these ceramic heat shields.

In the above-mentioned ceramic heat shield and heat-resistant structure, the fixed part of the ceramic heat shield is covered by the adjacent heat shield, and the sharp edge of the ceramic heat shield is eliminated. These measures can reduce the thermal shock caused by the ceramic heat shield. of the break. Moreover, one free end of the ceramic heat shield exposed to the high temperature environment can expand freely under thermal shock, thus avoiding the breakage of the ceramic sheet caused by the hindered expansion. In addition, these ceramic heat shield sheets partially overlap each other, resulting in gaps between the heat shield sheets and the heated surface, and gaps between the heat shield sheets. Therefore, air can form an air film on the surface of the heat shield sheets when passing into the flame cylinder through these gaps and gaps, and these heat shield sheets are protected from high temperature.

Description of drawings

Fig. 1 is a perspective view of an embodiment of a ceramic heat shield.

FIG. 2 is a side view of the ceramic heat shield of FIG. 1 .

Figure 3 is a schematic plan view of one embodiment of a heat resistant structure.

FIG. 4 is a partially enlarged schematic view of another angle of the heat-resistant structure in FIG. 3 .

detailed description

Before describing the embodiments in detail, it should be understood that the present invention is not limited to the detailed structures or arrangements of elements described herein below or in the accompanying drawings. The present invention can be implemented in other ways. Also, it should be understood that the phraseology and terminology used herein are for descriptive purposes only and should not be interpreted as limiting. The terms "including", "comprising", "having" and similar expressions used herein are meant to include the items listed thereafter, their equivalents and other additional items. In particular, when "a certain element" is described, the present invention does not limit the number of the element to one, but may also include a plurality.

Fig. 1 is a perspective view of an embodiment of a ceramic heat shield. The ceramic heat shield 10 includes a fixing portion 12 to be fixed to a heated surface 22 ( FIG. 4 ). Referring also to FIGS. 3 and 4 , in use, several ceramic heat shield sheets 10 are secured to the heated surface to cover the heated surface 22 . These ceramic heat shielding sheets 10 partially overlap each other, and the fixed portion 12 of each ceramic heat shielding sheet 10 is covered by at least one adjacent ceramic heat shielding sheet 10 .

In the illustrated embodiment, the edge 14 of the ceramic heat shield 10 is curved. More specifically, the ceramic heat shield 10 is oval. In other embodiments, the ceramic heat shield 10 may also be in other shapes with arc-shaped edges, such as circular. As shown in FIG. 2 , the ceramic heat shield sheet 10 has two opposite surfaces 16 and 18 , and the two opposite surfaces 16 and 18 are connected by a smooth curved surface at the edge 14 . Since the edge 14 of the ceramic heat shield sheet 10 has a smooth curved surface, the chance of thermal stress concentration at the edge is reduced, and the thermal shock resistance is improved.

In the illustrated embodiment, the fixing portion 12 of the ceramic heat shield 10 includes a fixing hole 12 . Also referring to FIG. 4 , the ceramic heat shielding sheet 10 can be fixed on the heated surface by passing the bolt through the fixing hole 12 . In other embodiments, the fixing part 12 may also adopt other forms, such as including a buckle part, so as to be connected to the heated surface in a buckle manner.

The fixing part 12 is not arranged at the center of the ceramic heat shielding sheet 10 , but is arranged at a position biased to the edge of the ceramic heat shielding sheet 10 . In such an embodiment, the ceramic heat shield sheet 10 includes a first end 24 (or referred to as a fixed end) provided with the fixing portion 12 and a second end 26 opposite to the first end 24 . In other embodiments, the fixing part 12 can be arranged at any other suitable position, as long as it can fix the ceramic heat shield sheet 10 to the heated surface 22 .

Figure 3 is a plan view of an embodiment of the heat-resistant structure. The heat-resistant structure 20 includes a heated surface 22 (see FIG. 4 ) and several ceramic heat shield sheets 10 covering the heated surface 22 . These ceramic heat shield sheets 10 partially overlap each other. The ceramic heat shield sheet 10 in this embodiment has the same structure as the ceramic heat shield sheet 10 in FIG. 1 . As mentioned above, each ceramic heat shield sheet 10 includes a fixed portion 12 fixed to the heated surface 22 , and the fixed portion 12 of each ceramic heat shield sheet 10 is covered by at least one adjacent ceramic heat shield sheet 10 . The edge 14 of the ceramic heat shield sheet 10 is arc-shaped. Each ceramic heat shield 10 has opposite surfaces 16 and 18 joined at an edge 14 with a smooth curve.

Referring to FIG. 4, the first end 24 of one ceramic heat shield 10a (the middle ceramic heat shield 10 in FIG. 4) is covered by an adjacent ceramic heat shield 10b (the right ceramic heat shield 10 in FIG. 4). The second end 26 covers, while the second end 26 of the ceramic heat shield 10a (the left ceramic heat shield 10 of FIG. 4 ) covers another adjacent ceramic heat shield 10c (the left ceramic heat shield 10c of FIG. 4 ). sheet 10) at the first end 24. Through this mutual partial overlap, the first ends 24 of the ceramic heat shield sheets 10 are covered by the adjacent ceramic heat shield sheets 10 , while the second ends 26 of the ceramic heat shield sheets 10 are exposed and are a free end. Therefore, the covered fixed part 12 can be protected from the direct impact of high temperature or high temperature flame (such as the flame in the combustion chamber), while the exposed free end or second end 26 can freely expand under thermal shock, thus avoiding Breakage of ceramic discs due to hindered expansion.

As mentioned above, the fixing part 12 can be fixed to the heated surface 22 by using a bolt or a buckle structure. In the illustrated embodiment, the fixed portion 12 is fixed to the heated surface 22 with bolts 28 .

As shown in FIG. 4 , the two surfaces 16 and 18 of the ceramic heat shield sheet 10 are the inner surface 16 facing the heated surface 22 and the outer surface 18 opposite to the inner surface 16 , respectively. There is a gap 30 between the inner surface 16 of the ceramic heat shield 10 and the heated surface 22 . In the specific embodiment shown in FIG. 4 , an angle is formed between the inner surface 16 of the ceramic heat shield 10 and the heated surface 22 . There are also gaps 32 between adjacent ceramic heat shielding sheets 10 , so air can flow between adjacent ceramic heat shielding sheets 10 .

The heated surface 22 has air holes 34 therethrough. The air holes 34 are in fluid communication with the gaps 30 and the slots 32 such that air can flow to the outer surface 18 of the ceramic heat shield 10 through the air holes 34 , the gaps 30 and the slots 32 in order. References to "outer surface" herein are made with reference to heated surface 22, which is actually the outer surface 18 that is heated. In one embodiment, the heated surface 22 is the inner surface of a combustion chamber of a gas turbine engine. Therefore, air can pass into the flame cylinder through the air holes 34, gaps 30 and slits 32 of the flame cylinder to form an air film on the surface 18 of the ceramic heat shield sheets 10, further protecting these ceramic heat shield sheets 10 from high temperature.

It should be noted that FIG. 3 only exemplarily shows an arrangement of the heat shielding sheets 10 . These heat shielding sheets 10 can also have other arrangements, as long as the fixing portion 12 of the heat shielding sheets can be covered by the adjacent heat shielding sheets 10 .

In short, in the above-mentioned ceramic heat shield and heat-resistant structure, the fixed part of the ceramic heat shield is covered by the adjacent heat shield, and the ceramic heat shield eliminates the sharp edges. These measures can reduce the heat loss of the ceramic heat shield Fracture caused by impact. Moreover, one free end of the ceramic heat shield exposed to the high temperature environment can expand freely under thermal shock, thus avoiding the breakage of the ceramic sheet caused by the hindered expansion. In addition, these ceramic heat shield sheets partially overlap each other, resulting in gaps between the heat shield sheets and the heated surface, and gaps between the heat shield sheets. Therefore, air can form an air film on the surface of the heat shield sheets when passing into the flame cylinder through these gaps and gaps, and these heat shield sheets are protected from high temperature.

The concepts described herein may be implemented in other forms without departing from their spirit and characteristics. The particular embodiments disclosed are to be considered as illustrative rather than restrictive. Accordingly, the scope of the invention is to be determined by the appended claims rather than by these preceding descriptions. Any change within the literal meaning of the claims and within the range of equivalency shall belong to the scope of these claims.

Claims (4)

1. A heat-resistant structure, comprising a heated surface and several ceramic heat-shielding sheets covered on the heated surface, each ceramic heat-shielding sheet includes a fixing portion for fixing to the heated surface, characterized in that these The ceramic heat shield sheets partially overlap each other, the fixed portion of each ceramic heat shield sheet is covered by at least one adjacent ceramic heat shield sheet, and each ceramic heat shield sheet includes a first end provided with the fixed portion and connected to the The second end opposite to the first end, the second end is exposed and is a free end; these ceramic heat shields include a first heat shield fixed to the heated surface, two second heat shields and a The third heat-shielding sheet, the two second heat-shielding sheets respectively cover the two side edges of the fixed part of the first heat-shielding sheet but expose the second end of the first heat-shielding sheet, the second heat-shielding sheet The three heat-shielding sheets cover the fixing portion of the first heat-shielding sheet and the opposite side edges of the two second heat-shielding sheets but expose the second end of the first heat-shielding sheet, and the first heat-shielding sheet There is a gap between the sheet, the two opposite side edges of the two second heat-shielding sheets, and the third heat-shielding sheet. 2. The heat-resistant structure according to claim 1, wherein the edge of each ceramic heat shield is arc-shaped, and each ceramic heat shield has two opposite surfaces, and the opposite two surfaces are on the The edges are connected with a smooth surface. 3. The heat-resistant structure according to claim 1, wherein the ceramic heat-shielding sheets each have an inner surface facing the heated surface and an outer surface opposite to the inner surface, the ceramic heat-shielding sheets There is a gap between the inner surface and the heated surface, and an included angle is formed between the inner surfaces of the ceramic heat shield sheets and the heated surface. 4. The heat-resistant structure according to claim 3, wherein the heated surface is the inner surface of the flame tube of the combustion chamber of the gas turbine and has through air holes, and the air holes are in fluid communication with the gaps and gaps, so that Air can flow to the outer surfaces of these ceramic heat shield sheets sequentially through the air holes, gaps and gaps.