Sealing structure of turbine stator blade and gas turbine

Abstract

The present invention relates to a sealing structure of a turbine stator blade, wherein the turbine stator blade is provided with a sealing sheet groove, wherein a sealing sheet is arranged in the sealing sheet groove; wherein the turbine stator blade is also provided with a receiving groove, wherein the receiving groove is located at one side of the sealing sheet groove and is communicated with the sealing sheet groove, wherein a temperature measuring element is arranged in the receiving groove, and the inner side wall of the receiving groove fully fits the outer surface of the temperature measuring element. The sealing structure of the turbine stator blade of the present technical solution is provided with a receiving groove at one side of the sealing sheet groove, so that the temperature measuring element and the sealing sheet can be retained at the same time, thereby ensuring the sealing between two adjacent turbine stator blades, greatly reducing the leakage of cooling air of the turbine stator blade, and making the measurement of the temperature measuring element more accurate; at the same time, by making the inner side wall of the receiving groove fully fit the outer surface of the temperature measuring element, the temperature measuring element is in continuous and full contact with the body of the turbine stator blade during measurement, making the measurement of the temperature measuring element more accurate, and improving the reliability of the measurement of the temperature measuring element.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal engines, and in particular to a sealing structure of a turbine stator blade and a gas turbine. Background Art

[0002] The turbine stator blades of gas turbines work in high-temperature combustion gases, bearing huge heat loads, and undergoing severe thermal stress and strain. The high-temperature combustion gases significantly reduce their creep life, leading to common faults such as blade deformation, ablation, and fracture of the turbine stator blades. The premise for ensuring the cooling effect of air-cooled turbine blades is to accurately obtain the blade surface temperature in order to determine the appropriate cooling method and cooling air volume, otherwise the cooling efficiency of the cooling system will be seriously reduced. Therefore, it is of great significance to improve the measurement accuracy of turbine blade surface temperature and provide a basis for thermal analysis and blade cooling design.

[0003] At present, the main surface temperature test methods for gas turbine turbine stator blades at home and abroad include infrared radiation, temperature indicating paint, crystal and thermocouple, etc. Infrared radiation temperature measurement is a non-contact measurement technology with a high upper limit for temperature measurement and can obtain continuous temperature field data, but it is affected by the emissivity measurement and has problems such as large measurement error, low temperature resolution and spatial resolution; temperature indicating paint and crystal temperature measurement technology do not require test leads, but can only obtain the highest temperature of the test state and cannot be monitored in real time; armored thermocouples commonly used in engineering have the advantages of simple structure, wide range, high accuracy and convenient long-distance signal transmission, but this method requires the measurement point to be buried in the blade, which destroys the blade structure, changes the heat transfer performance of the blade, reduces the measurement accuracy, and makes it difficult for the temperature of the measurement point to be consistent with the surface temperature, and it cannot be buried in thin-walled structures such as the trailing edge of the blade.

[0004] In order to solve the drawbacks of traditional thermocouple installation methods and improve the accuracy of turbine blade surface temperature measurement, Xu Yi and others from the China Aero Engine Gas Turbine Research Institute proposed a method of using micro-thermocouples to test the surface temperature of turbine blades. This method can effectively solve the temperature measurement error caused by the embedding of thermocouples. This method fixes the thermocouple wire on the blade surface through an alumina coating to obtain the blade surface temperature, which is referred to as micro-thermocouple temperature measurement.

[0005] The sealing sheet of the turbine stator blade of a gas turbine is generally a sheet-like structure. A connecting part is provided at both ends of the turbine stator blade. Two adjacent turbine stator blades are connected through the end face of the connecting part, and the sealing is achieved through the sealing sheet. When testing the whole gas turbine, the surface temperature of the turbine stator blade is measured by a micro-thermocouple temperature measurement method. The micro-thermocouple requires a certain routing width during the lead-out process and is in contact with the blade body throughout the entire process. Due to the obstruction of the upper and lower sealing sheets at both ends of the turbine stator blade, the temperature measurement point lead cannot be led out. In order to lead out the temperature measurement point lead, the general practice is to directly remove the upper and lower sealing sheets, but doing so will increase the leakage area of ​​the circumferential clearance of the turbine stator blade, greatly increase the leakage flow of the cooling air, and affect the pressure and flow of the cooling air of the stator blade, causing disturbances to the temperature of the measurement surface, resulting in inaccurate measurement results. At the same time, due to the large gap between the micro-thermocouple in the sealing sheet groove and the blade body, the micro-thermocouple cannot be in contact with the blade body throughout the entire process, resulting in inaccurate measurement results and affecting the reliability of temperature measurement by the micro-thermocouple. Summary of the invention

[0006] The first purpose of the present invention is to propose a sealing structure for a turbine stator blade, aiming to solve the technical problem that the existing turbine stator blades have limited structural space and the sealing sheet is directly removed in order to achieve temperature measurement, resulting in poor sealing of the turbine stator blades and affecting the temperature measurement effect.

[0007] A second objective of the present invention is to provide a gas turbine.

[0008] To achieve the above-mentioned first objective, the present invention provides a sealing structure for a turbine stator blade, comprising a turbine stator blade, wherein the turbine stator blade is provided with a sealing sheet groove, and a sealing sheet is arranged in the sealing sheet groove; wherein:

[0009] The turbine stator blade is also provided with a receiving groove, which is located at one side of the sealing plate groove and communicated with the sealing plate groove. A temperature measuring element is arranged in the receiving groove, and the inner side wall of the receiving groove fully fits the outer surface of the temperature measuring element.

[0010] As a further improvement of the present invention: the gap between the temperature measuring element and the sealing sheet groove and the accommodating groove is filled by repair welding.

[0011] As a further improvement of the present invention: the turbine stator blade includes a suction surface and a pressure surface, the suction surface and the pressure surface are respectively located on both sides of the turbine stator blade, and both ends of the suction surface and the pressure surface are provided with sealing sheet grooves and accommodating grooves.

[0012] As a further improvement of the present invention: a notch is provided on the sealing sheet in the sealing sheet groove.

[0013] As a further improvement of the present invention: the length of the notch is the same as the length of the accommodating groove.

[0014] As a further improvement of the present invention: the temperature measuring element adopts a thermocouple.

[0015] As a further improvement of the present invention: a cavity is provided inside the turbine stator blade.

[0016] As a further improvement of the present invention: it also includes blade rings, which are respectively located at the two ends of the turbine stator blade, the blade ring is provided with a lead hole, the temperature measuring element is provided with a lead, a part of the lead is connected to an external element through one end of the turbine stator blade and through the lead hole, and the other part of the lead is connected to an external element through one end of the turbine stator blade and through the cavity and the lead hole.

[0017] As a further improvement of the present invention: the surface of the temperature measuring element is covered with a coating.

[0018] To achieve the second objective above, the present invention further provides a gas turbine, which includes the sealing structure of the turbine stator blades mentioned above.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The sealing structure of the turbine stator blade of the technical solution has a receiving groove on one side of the sealing plate groove, so that the temperature measuring element and the sealing plate can be retained at the same time, thereby ensuring the sealing between two adjacent turbine stator blades, greatly reducing the leakage of cooling air of the turbine stator blades, and making the measurement of the temperature measuring element more accurate; at the same time, the inner side wall of the receiving groove fully fits the outer surface of the temperature measuring element, and the temperature measuring element is in continuous and full contact with the body of the turbine stator blade during measurement, so that the measurement of the temperature measuring element is more accurate and the reliability of the measurement of the temperature measuring element is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0022] Figure 1 This is a schematic structural diagram of an embodiment of a sealing sheet of the present application;

[0023] Figure 2 This is a schematic structural diagram of an embodiment of a turbine stator blade of the present application;

[0024] Figure 3 for Figure 2Sectional view in the middle AA direction;

[0025] Figure 4 for Figure 2 Cross-section in the middle BB direction;

[0026] Figure 5 for Figure 2 Cross-section in the middle M direction;

[0027] Figure 6 This is a schematic structural diagram of another embodiment of the sealing sheet of the present application;

[0028] Figure 7 This is a connection diagram of a lead wire embodiment of the temperature measuring element of the present application.

[0029] Description of Figure Numbers:

[0030]

[0031] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] When testing the whole gas turbine, the surface temperature of the turbine stator blade is measured by the micro-thermocouple temperature measurement method. The micro-thermocouple needs a certain routing width during the lead-out process and is in contact with the blade body throughout the process. Due to the obstruction of the upper and lower sealing sheets at both ends of the turbine stator blade, the temperature measurement point lead cannot be led out. In order to lead out the temperature measurement point lead, the general practice is to directly remove the upper and lower sealing sheets, but doing so will increase the leakage area of ​​the circumferential gap of the turbine stator blade, greatly increase the leakage flow of the cooling air, and affect the pressure and flow of the cooling air of the stator blade, causing disturbances to the temperature of the measurement surface, resulting in inaccurate measurement results. At the same time, due to the large gap between the micro-thermocouple in the sealing sheet groove and the blade body, the micro-thermocouple cannot be in contact with the blade body throughout the process, which also leads to inaccurate measurement results and affects the reliability of micro-thermocouple temperature measurement.

[0036] The purpose of the present invention is to propose a sealing structure for a turbine stator blade, aiming to solve the technical problem that the existing turbine stator blades have limited structural space and the sealing sheet is directly removed in order to achieve temperature measurement, resulting in poor sealing of the turbine stator blades and affecting the temperature measurement effect.

[0037] See also Figure 1-Figure 7 In one embodiment of the sealing structure of the turbine stator blade of the present application, the sealing structure of the turbine stator blade includes a turbine stator blade 1, wherein the turbine stator blade 1 is provided with a sealing sheet groove, and a sealing sheet is arranged in the sealing sheet groove; wherein,

[0038] The turbine stator blade 1 is also provided with a receiving groove, which is located at one side of the sealing plate groove and communicated with the sealing plate groove. A temperature measuring element is arranged in the receiving groove, and the inner side wall of the receiving groove fully fits the outer surface of the temperature measuring element.

[0039] For more information, see Figure 2-Figure 3In this embodiment, the turbine stator blade 1 is a hollow cooling blade. The turbine stator blade 1 and the adjacent turbine stator blade 101 are sealed by a sealing structure, and the sealing sheet is fixed in the sealing sheet groove by riveting. A receiving groove is provided on one side of the sealing sheet groove, so that the temperature measuring element can be placed in the receiving groove to measure the temperature of the turbine stator blade 1; at the same time, the temperature measuring element does not completely occupy the space of the sealing sheet groove, so that the sealing sheet can be retained in the sealing sheet groove. In addition, by setting the inner side wall of the receiving groove to fully fit the outer surface of the temperature measuring element, it is possible to avoid a gap between the inner side wall of the receiving groove and the temperature measuring element, which causes the temperature measuring element to be unable to continuously fit the body of the turbine stator blade 1.

[0040] The sealing structure of the turbine stator blade of the present technical solution has a receiving groove on one side of the sealing plate groove, so that the temperature measuring element and the sealing plate can be retained at the same time, thereby ensuring the sealing between two adjacent turbine stator blades, greatly reducing the leakage of cooling air of the turbine stator blade 1, and making the measurement of the temperature measuring element more accurate; at the same time, the inner side wall of the receiving groove is fully fitted with the outer surface of the temperature measuring element, and the temperature measuring element is in continuous and full contact with the body of the turbine stator blade 1 during measurement, so that the measurement of the temperature measuring element is more accurate and the reliability of the measurement of the temperature measuring element is improved.

[0041] Furthermore, in a certain embodiment, the gap between the temperature measuring element and the sealing sheet groove and the receiving groove is filled by repair welding. In this embodiment, the repair welding is specifically performed by argon arc welding and polished to make it smooth. In other embodiments, solid metal can also be filled to reduce the gap between the temperature measuring element and the sealing sheet groove and the receiving groove.

[0042] Furthermore, in a certain embodiment, the outer surface of the temperature measuring element is covered with a coating, and the coating is used to fix the temperature measuring element on the inner wall of the containing groove.

[0043] Furthermore, in a certain embodiment, the turbine stator blade 1 includes a suction surface 8 and a pressure surface 9, and the suction surface 8 and the pressure surface 9 are respectively located on both sides of the turbine stator blade 1, and sealing sheet grooves and accommodating grooves are provided at both ends of the suction surface 8 and the pressure surface 9.

[0044] For more information, see Figure 3In this embodiment, both ends of the suction surface 8 and the pressure surface 9 of the turbine stator blade 1 are provided with connecting parts. On one side of the suction surface 8, the end surface of the connecting part located at the top is provided with an upper circulation symmetry surface A10, and the end surface of the connecting part located at the bottom is provided with a lower circulation symmetry surface A12; on one side of the pressure surface 9, the end surface of the connecting part located at the top is provided with an upper circulation symmetry surface B11, and the end surface of the connecting part located at the bottom is provided with a lower circulation symmetry surface B13. Among them, the upper circulation symmetry surface A10 of the turbine stator blade 1 and the upper circulation symmetry surface B11 of the adjacent turbine stator blade 101 are sealed by the upper sealing sheet A2, the upper sealing block A3, and the upper sealing block B4; the lower circulation symmetry surface A12 of the turbine stator blade 1 and the lower circulation symmetry surface B13 of the adjacent turbine stator blade 101 are sealed by the lower sealing sheet A5, the lower sealing block A6, and the lower sealing block B7.

[0045] Specifically, in this embodiment, both ends of the suction surface 8 and the pressure surface 9 are provided with sealing sheet grooves and accommodating grooves, and the sealing sheet grooves include: an upper sealing sheet groove A14 located on the upper circulation symmetry surface A10, an upper sealing sheet groove B15 located on the upper circulation symmetry surface B11, a lower sealing sheet groove A16 located on the lower circulation symmetry surface A12, and a lower sealing sheet groove B17 located on the lower circulation symmetry surface B13. The accommodating grooves include: a first accommodating groove 31 connected to the upper sealing sheet groove A14, a second accommodating groove 32 connected to the upper sealing sheet groove B15, a third accommodating groove 33 connected to the lower sealing sheet groove A16, and a fourth accommodating groove 34 connected to the lower sealing sheet groove B17.

[0046] In summary, since the suction surface 8 and the pressure surface 9 on both sides of the turbine stator blade 1 are respectively provided with sealing sheet grooves and accommodating grooves, both ends of the two sides of the turbine stator blade 1 can be placed with temperature measuring elements and sealing sheets. Since the depth of the accommodating grooves is smaller than the depth of the sealing sheet grooves, the first accommodating groove 31, the second accommodating groove 32, the third accommodating groove 33, the fourth accommodating groove 34 and the sealing sheet grooves corresponding to the aforementioned accommodating grooves should be filled with welding before temperature measurement, and the surface of the welding area should be polished and smoothed, and then the temperature measuring element should be placed and sprayed.

[0047] It is worth noting that the lengths of the first accommodating groove 31 , the second accommodating groove 32 , the third accommodating groove 33 and the fourth accommodating groove 34 depend on the number of temperature measuring elements passing through the corresponding circular symmetric surface and the width limit of the circular symmetric surface itself. Figure 2 and Figure 6 In the figure, L1 represents the length of the first receiving groove 31 in the airflow direction, L2 represents the length of the first receiving groove 32 in the airflow direction, L3 represents the length of the first receiving groove 33 in the airflow direction, and L4 represents the length of the first receiving groove 34 in the airflow direction; Figure 5 Wherein h represents the depth of any of the above-mentioned receiving grooves.

[0048] Furthermore, in a certain embodiment, the sealing sheet in the sealing sheet groove is provided with a notch, and the length of the notch is the same as the length of the accommodating groove.

[0049] For more information, see Figure 6 In this embodiment, the sealing sheets are all provided with notches. The length of the notch of each sealing sheet is the same as the length of the corresponding receiving groove. The width H1 of the upper sealing sheet A2 is opened to be flush with the upper circulation symmetry plane A10; the width H2 of the upper sealing sheet B21 is opened to be flush with the upper circulation symmetry plane B11; the width H3 of the lower sealing sheet A5 is opened to be flush with the lower circulation symmetry plane A12; the width H4 of the lower sealing sheet B22 is opened to be flush with the lower circulation symmetry plane B13. Since the sealing sheet is provided with notches, the operator can perform fill-in welding in the notch area and the receiving groove area of ​​the sealing sheet, so as to improve the effect of the temperature measuring element fully contacting the body of the turbine stator blade 1.

[0050] Furthermore, in a certain embodiment, the sealing structure of the turbine stator blade further includes a cavity 18 , and the cavity 18 is provided in the turbine stator blade 1 .

[0051] Specifically, in this embodiment, the cavity 18 is used to provide a channel for the lead wire of the temperature measuring element to pass through.

[0052] Furthermore, in a certain embodiment, the sealing structure of the turbine stator blade also includes a blade ring 19, and the blade ring 19 is respectively located at both ends of the turbine stator blade 1, and the blade ring 19 is provided with a lead hole 20, and the temperature measuring element is provided with a lead, a part of the lead is connected to an external element through one end of the turbine stator blade 1 and through the lead hole 20, and the other part of the lead is connected to an external element through one end of the turbine stator blade 1 and through the cavity 18 and the lead hole 20.

[0053] Specifically, please combine Figure 3 and Figure 7 In this embodiment, the external element is the turbine cylinder 23, and a part of the lead wire of the temperature measuring element located on the suction surface 8 is led out of the turbine cylinder 23 through the upper circulation symmetry surface A10 and the lead wire hole 20 on the blade ring 19, and the other part is led out of the turbine cylinder 23 through the lower circulation symmetry surface A12 of the suction surface 8, the cavity 18 and the lead wire hole 20 on the blade ring 19 in sequence;

[0054] In addition, part of the leads of the temperature measuring element located on the pressure surface 9 are led out of the turbine cylinder 23 through the upper circulation symmetry plane B11 and the lead hole 20 on the blade ring 19, and the other part is led out of the turbine cylinder 23 through the lower circulation symmetry plane B13, the cavity 18 and the lead hole 20 on the blade ring 19 in turn.

[0055] Furthermore, in a certain embodiment, the temperature measuring element is a thermocouple.

[0056] The present invention also provides a gas turbine, which includes a sealing structure for a turbine stator blade. The specific structure of the sealing structure refers to the above embodiment. Since the gas turbine adopts all the technical solutions of all the embodiments of the sealing structure, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0057] In summary, the technical solution designs the upper sealing sheet A and the lower sealing sheet A on the suction surface of the turbine stator blade and the upper sealing sheet B and the lower sealing sheet B on the turbine stator blade adjacent to the pressure surface of the turbine stator blade. Compared with directly removing the sealing sheet, the sealing sheet structure of the present invention retains the sealing sheet, so that the leakage area of ​​the circumferential clearance of the turbine stator blade remains basically unchanged, thereby greatly reducing the leakage of cooling air in the whole machine test, ensuring the accuracy of the turbine stator blade temperature measurement; and greatly reducing the impact of temperature measurement on the unit efficiency.

[0058] Secondly, the technical solution opens accommodating grooves on the circular symmetry surface A on the suction surface of the turbine stator blade, the circular symmetry surface B on the pressure surface, the circular symmetry surface A below the suction surface, and the circular symmetry surface B below the pressure surface, and fills the sealing plate grooves corresponding to the accommodating grooves by welding. This ensures that the micro-thermocouple is in contact with the turbine stator blade body throughout the process when measuring the stator blade temperature, thereby improving the measurement reliability and unit safety.

[0059] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A sealing structure for a turbine stator blade, characterized in that: It comprises a turbine stator blade, wherein the turbine stator blade is provided with a sealing sheet groove, and a sealing sheet is arranged in the sealing sheet groove; wherein, The turbine stator blade is also provided with a receiving groove, which is located at one side of the sealing plate groove and communicated with the sealing plate groove. A temperature measuring element is arranged in the receiving groove, and the inner side wall of the receiving groove fully fits the outer surface of the temperature measuring element.

2. The sealing structure of the turbine stator blade according to claim 1, characterized in that: The gaps between the temperature measuring element and the sealing sheet groove and the accommodating groove are filled by repair welding.

3. The sealing structure of the turbine stator blade according to claim 1, characterized in that: The turbine stator blade comprises a suction surface and a pressure surface. The suction surface and the pressure surface are respectively located on two sides of the turbine stator blade. Both ends of the suction surface and the pressure surface are provided with sealing sheet grooves and accommodating grooves.

4. The sealing structure of the turbine stator blade according to claim 1, characterized in that: The sealing sheet in the sealing sheet groove is provided with a notch.

5. The sealing structure of the turbine stator blade according to claim 4, characterized in that: The length of the notch is the same as the length of the accommodating groove.

6. The sealing structure of the turbine stator blade according to claim 1, characterized in that: A cavity is provided in the turbine stator blade.

7. The sealing structure of the turbine stator blade according to claim 6, characterized in that: It also includes a blade ring, which is respectively located at both ends of the turbine stator blade. The blade ring is provided with a lead hole, and the temperature measuring element is provided with a lead. A part of the lead is connected to an external element through one end of the turbine stator blade and through the lead hole, and the other part of the lead is connected to an external element through one end of the turbine stator blade and through the cavity and the lead hole.

8. The sealing structure of a turbine stator blade according to claim 1, characterized in that: The temperature measuring element is a thermocouple.

9. The sealing structure of a turbine stator blade according to claim 1, characterized in that: The surface of the temperature measuring element is covered with a coating.

10. A gas turbine, characterized in that: A sealing structure for a turbine stator blade comprising the sealing structure as claimed in any one of claims 1 to 9.

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