An ebc coating structure, thermal protection material, and gas turbine

Abstract

The present application relates to a kind of EBC coating structure, heat protection material and gas turbine, EBC coating structure is used to be arranged on ceramic tile substrate for protection, the main material of the ceramic tile substrate includes alumina and mullite, the EBC coating structure includes first alumina coating and second alumina coating, the first alumina coating is located on the surface of ceramic tile substrate, the second alumina coating is located on the first alumina coating, the total thickness of the first alumina coating and second alumina coating is 500~1000 μm, the porosity of the first alumina coating is 20%~40%, the porosity of the second alumina coating is 5%~20%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbine, in particular to an EBC coating structure, thermal protection material and gas turbine. BACKGROUND

[0002] The inner wall of the combustion chamber of the F-class gas turbine is exposed to a high-temperature gas environment with high corrosiveness, and the gas temperature can be as high as 1500℃ or above. Therefore, a thermal protection material is needed to protect the metal inner wall of the combustion chamber. A ceramic tile composed of alumina and mullite is a thermal protection material currently used. The ceramic tile is resistant to high temperature, oxidation and low thermal conductivity, making it suitable for the combustion chamber environment.

[0003] However, the service environment of the combustion chamber is extremely harsh. In addition to high temperature, there is also water vapor corrosion. The high-temperature gas carrying water vapor and other corrosive substances will continuously scour the surface of the ceramic tile. The mullite component in the ceramic tile will react with the water vapor, consuming the silicon dioxide component therein, leading to corrosion of the ceramic tile, and in severe cases, even cracking, which is fatal to the running gas turbine. Therefore, in order to improve the erosion and corrosion resistance of the ceramic tile, an additional coating is usually applied to the ceramic tile in the area that is more severely scoured by the gas. The coating is composed of alumina, and the total thickness of the coating is about 300μm. However, in this way, the coating is also prone to wear after long-term use. By observing the ceramic tile after service, it is found that in most cases the coating on the surface of the tile is consumed, and there are still traces of gas scouring on the surface of the tile. Therefore, the protection of the ceramic tile itself by simply using an alumina coating in the prior art is limited and needs to be further improved. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present application is to provide an EBC coating structure, thermal protection material and gas turbine. The EBC coating structure can well protect the ceramic tile substrate, and is not easy to detach and consume, thereby prolonging the service life of the ceramic tile and reducing the replacement frequency.

[0005] To achieve the above-mentioned purpose, the present application provides an EBC coating structure for protecting the ceramic tile substrate. The main material of the ceramic tile substrate includes alumina and mullite. The EBC coating structure includes a first alumina coating and a second alumina coating. The first alumina coating is located on the surface of the ceramic tile substrate, and the second alumina coating is located on the first alumina coating. The total thickness of the first alumina coating and the second alumina coating is 500~1000μm. The porosity of the first alumina coating is 20%~40%, and the porosity of the second alumina coating is 5%~20%.

[0006] Further, the thickness ratio of the first alumina coating layer to the second alumina coating layer is 1:1 to 3:1.

[0007] Further, the first alumina coating layer is coated and sintered on the ceramic tile substrate by a slurry method.

[0008] Further, the second alumina coating layer is attached on the first alumina coating layer by an atmospheric plasma spraying method.

[0009] The present application also provides a thermal protection material, comprising a ceramic tile substrate, wherein the ceramic tile substrate is further provided with the above-mentioned EBC coating structure.

[0010] The present application also provides a gas turbine, wherein the above-mentioned thermal protection material is arranged on the metal surface of the combustion chamber of the gas turbine.

[0011] As described above, the EBC coating structure, the thermal protection material, and the gas turbine according to the present application have the following beneficial effects:

[0012] By arranging the first alumina coating layer and the second alumina coating layer, the total thickness of the EBC coating structure is increased, the erosion of the ceramic tile substrate by high-temperature gas is effectively reduced, the first alumina coating layer can be stably and tightly attached on the ceramic tile substrate, and the first alumina coating layer can prevent the ceramic tile substrate from being peeled off under the condition of heating and long-term use. The first alumina coating layer also plays a protective role and blocks the water vapor from corroding the ceramic tile substrate in the case of wear of the second alumina coating layer. The second alumina coating layer can effectively block the corrosion of water vapor and stably attach the first alumina coating layer. The entire EBC coating structure has good protection performance, is stable and reliable, can prolong the service life of the ceramic tile, reduces the replacement frequency, and can well protect the inner wall of the combustion chamber of the gas turbine. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 FIG. 1 is a structural schematic diagram of the EBC coating structure according to the present application.

[0014] ELEMENT NUMBER EXPLANATION

[0015] 1 ceramic tile substrate

[0016] 2 first alumina coating layer

[0017] 3 second alumina coating layer DETAILED DESCRIPTION

[0018] The embodiments of the present application are described below by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification.

[0019] It is to be understood that the structures, proportions, sizes, etc. shown in the drawings of the present disclosure are merely intended to facilitate the understanding of the content disclosed in the present disclosure, to be understood and read by those skilled in the art, and are not intended to limit the conditions under which the present disclosure can be implemented, and therefore do not have substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present disclosure, should still fall within the scope of the technical content disclosed by the present disclosure. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and the like used in the present disclosure are only for the convenience of clear description, and are not intended to limit the scope of the present disclosure, and the change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the scope of the present disclosure.

[0020] Referring to Figure 1 The present disclosure provides an EBC coating structure for protecting the ceramic tile substrate 1, which mainly includes alumina and mullite, and the EBC coating structure includes a first alumina coating layer 2 and a second alumina coating layer 3. The first alumina coating layer 2 is located on the surface of the ceramic tile substrate 1, and the second alumina coating layer 3 is located on the first alumina coating layer 2. The total thickness of the first alumina coating layer 2 and the second alumina coating layer 3 is 500-1000 μm. The porosity of the first alumina coating layer 2 is 20%-40%, and the porosity of the second alumina coating layer 3 is 5%-20%. The thickness ratio of the first alumina coating layer 2 to the second alumina coating layer 3 is preferably 1:1-3:1.

[0021] The EBC coating structure disclosed in the present disclosure has the same material as the first alumina coating layer 2 and the second alumina coating layer 3, and has a porosity of 5%-20%, which can stably adhere to the first alumina coating layer 2. At the same time, this porosity can effectively block the corrosion of water vapor and form good protection. The first alumina coating layer 2 has a porosity of 20%-40%, which ensures the matching with the ceramic tile substrate 1 and stably and tightly adheres to the ceramic tile substrate 1. The first alumina coating layer 2 also plays a protective role and blocks the corrosion of water vapor to the ceramic tile substrate 1 in the case of wear of the second alumina coating layer 3. The total thickness of the first alumina coating layer 2 and the second alumina coating layer 3 is 500-1000 μm, which can avoid the problem of insufficient protection due to the easy consumption of the EBC coating structure due to being too thin, and can also avoid the problem of easy falling off due to being too thick.

[0022] In the present disclosure, preferably, the first alumina coating layer 2 is coated and sintered on the ceramic tile substrate 1 by slurry method, and the second alumina coating layer 3 is adhered to the first alumina coating layer 2 by atmospheric plasma spraying method. In this way, the combination of the two methods can effectively reduce the cost.

[0023] The EBC coating structure of the present application, after being arranged on the ceramic tile substrate 1, forms a thermal protection material with the pre-tile ceramic substrate 1, which can be used in a gas turbine for ground power generation, especially in the combustion chamber to protect the metal inner wall. Of course, the thermal protection material is also used for the protection of metal parts in other high-temperature gas environments with high corrosivity.

[0024] The present application also protects a gas turbine, which is provided with the above-mentioned thermal protection material in the combustion chamber of the gas turbine, wherein the ceramic tile substrate 1 is mounted on the metal inner wall of the combustion chamber.

[0025] In summary, the present application effectively overcomes the shortcomings of the prior art and has high industrial utilization value.

[0026] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical ideas disclosed by the present application should be covered by the claims of the present application.

Claims

1. An EBC coating structure for providing protection when disposed on a ceramic tile substrate (1) comprising mainly alumina and mullite, characterized in that: The EBC coating structure comprises a first alumina coating (2) on the surface of a ceramic tile substrate (1) and a second alumina coating (3) on the first alumina coating (2), the total thickness of the first alumina coating (2) and the second alumina coating (3) is 500-1000 μm, the thickness ratio of the first alumina coating (2) to the second alumina coating (3) is 1:1-3:1, the porosity of the first alumina coating (2) is 20%-40%, and the porosity of the second alumina coating (3) is 5%-20%.

2. The EBC coating structure of claim 1, wherein: The first alumina coating (2) is coated on the ceramic tile substrate (1) by slurry method and sintered.

3. The EBC coating structure of claim 1, wherein: The second alumina coating (3) is attached to the first alumina coating (2) by atmospheric plasma spraying method.

4. A thermal protection material comprising a ceramic tile substrate (1), characterized in that: The ceramic tile substrate (1) is further provided with the EBC coating structure as claimed in any one of claims 1-3.

5. A gas turbine engine characterized by: The thermal protection material as claimed in claim 4 is arranged on the metal surface of the combustion chamber of a gas turbine.

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