A multi-position joint adjustment combustion turbine blade chord cooling structure and control method

Abstract

The present invention discloses a multi-position jointly regulated mid-chord cooling structure and control method for a combustion engine blade. The structure includes a blade body and a blade cover. Multi-flow cooling channels are provided in the blade body. Top outflow holes A and B are provided at the top of the blade body. Connecting bridges A to F are arranged on the channel partitions. Guide vanes A and B are arranged in the turning area. Turbine structures are arranged on the first to third column channel surfaces and the corresponding inner surfaces of the blade cover. The control method includes: 1) rapid coarse adjustment of cold air flow and rapid matching of channel resistance; 2) rapid coarse adjustment of air distribution between channels; 3) precise fine adjustment of flow between channels; 4) precise fine adjustment of flow and cooling in the turning area; 5) rapid coarse adjustment of pressure and suction surface cooling; 6) precise fine adjustment of local high-temperature areas of the blade. The present invention is applicable to combustion engine blades with different heat loads, blade profiles, and internal cooling channels, and can also quickly adapt to cooling requirements and changes in flow and heat transfer characteristics under varying operating conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas turbine blade cooling, and in particular relates to a multi-position jointly regulated gas turbine blade mid-chord cooling structure and a control method. Background Art

[0002] Competition in the gas turbine industry is becoming increasingly fierce. According to thermodynamic cycle analysis, increases in gas turbine power and efficiency inevitably come with increases in turbine blade inlet temperatures. Currently, turbine inlet temperatures have long exceeded the material's maximum temperature resistance, and the gap between these two levels is widening year by year. Finding efficient and effective turbine blade cooling methods is crucial to ensuring safe and stable gas turbine operation.

[0003] The mid-chord region of a gas turbine blade has a large heat exchange area. It is typically equipped with U-shaped channels with corners or multi-pass serpentine channels. To enhance the channel's heat transfer capacity, flow-disrupting structures such as ribs and spherical sockets / bulges are often incorporated. To reduce pressure loss, guide vanes or connecting bridges are often placed on the channel sidewalls in the turning region. However, the current research and application of cooling structures in the mid-chord region of gas turbine blades still face numerous challenges. First, most research on cooling structures focuses on channels with constant cross-sections. However, due to the influence of the turbine blade profile, the internal cooling channels of actual turbine blades often exhibit variable cross-section characteristics, resulting in a deviation in the cooling performance of the channels from the ideal design state. Second, during actual operation, gas turbines do not always operate at rated conditions. Changes in their loads cause changes in the flow rate of the internal cooling medium, and changes in flow state lead to a decrease in the performance of the blade's internal cooling channels. Finally, when testing the internal cooling structure of turbine blades, changing the structural parameters requires replacing the entire blade, which is costly. In addition, the internal cooling structure of gas turbines is difficult to process. The integrated processing of the mid-chord cooling channel with multiple cooling structures is relatively complex and has large processing errors, resulting in the channel's cooling effect not meeting expectations. Therefore, in order to ensure the cooling performance of the mid-chord channel of a turbine blade, it is urgent to develop a set of testing and application methods for turbine blade cooling structures that are suitable for multiple channels and multiple operating conditions. Summary of the Invention

[0004] In response to the deficiencies of the above-mentioned prior art, the present invention provides a multi-position jointly adjustable mid-chord cooling structure and control method for a gas turbine blade. By arranging high-temperature resistant, low-thermal-resistance flexible electro-sensitive layers and electrode sheets on the surface of each structure inside the mid-chord cooling channel of the gas turbine blade, rapid joint adjustment of the multi-position cooling structure is achieved by changing the voltage of the electrode sheets. The processing difficulty and testing cost are low, and the method is widely applicable to gas turbine blades with different heat loads, blade profiles and internal cooling channels. It can also quickly adapt to the cooling requirements and changes in flow and heat transfer characteristics of the blades under variable operating conditions.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A multi-position jointly adjusted combustion turbine blade mid-chord cooling structure, comprising a blade body and a blade cover;

[0007] The top of the blade body is provided with a top outflow hole A and a top outflow hole B. A cavity structure is provided inside the blade body. The cavity structure is blocked by a channel partition to form a cooling medium channel. The cooling medium channel is a multi-flow channel. When it is a three-flow serpentine cooling channel, the cooling medium flows in from the bottom of the blade body during operation, passes through the first row of channels and reaches the first turning area. Part of the cooling medium flows out from the top outflow hole A, and the rest flows out from the top outflow hole B after passing through the second row of channels, the second turning area and the third row of channels respectively; the channel partition between the first row of channels and the second row of channels is provided with a connecting bridge A, a connecting bridge B and a connecting bridge C, and the channel partition between the second row of channels and the third row of channels is provided with a connecting bridge D, a connecting bridge E and a connecting bridge F; a guide vane A is provided in the first turning area, and a guide vane B is provided in the second turning area; a turbulent flow structure is provided on the surface of the first row of channels, the second row of channels and the third row of channels, as well as on the inner surface of the blade cover corresponding to the three rows of channels, and the turbulent flow structure is a rib, a ball socket and a ball-convex channel surface enhanced heat exchange structure.

[0008] A further improvement of the present invention is that a multi-step structure is arranged at the connection between the blade body and the blade cover.

[0009] A further improvement of the present invention is that a plurality of threaded holes are arranged on the surface of the blade body, and a plurality of through holes are arranged on the surface of the blade cover plate. During assembly, the countersunk screws are passed through the through holes on the blade cover plate and screwed into the threaded holes on the surface of the blade body to connect the blade body and the blade cover plate.

[0010] A further improvement of the present invention is that the first electrode sheet to the thirty-first electrode sheet and the first high-temperature-resistant low-thermal-resistance flexible electro-sensitive layer to the sixth high-temperature-resistant low-thermal-resistance flexible electro-sensitive layer are arranged inside the blade.

[0011] A further improvement of the present invention is that a first high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer and a second high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer are respectively arranged inside the top outlet hole A and the top outlet hole B, and the first electrode sheet to the fourth electrode sheet are arranged between the first high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer and the blade body, and the fifth electrode sheet to the eighth electrode sheet are arranged between the second high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer and the blade body inside the top outlet hole B.

[0012] A further improvement of the present invention is that a third high-temperature resistant, low-thermal-resistance flexible electro-sensitive layer is arranged on the surface of guide vane A and guide vane B, and the ninth to twentieth electrode sheets are arranged between the surface of guide vane A and the third high-temperature resistant, low-thermal-resistance flexible electro-sensitive layer.

[0013] A further improvement of the present invention is that the surfaces of the connecting bridges A, B, C, D, E and F of the channel partition are all arranged with a fourth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer, and the twenty-first electrode sheet to the twenty-fourth electrode sheet are arranged between the surface of the connecting bridge D and the fourth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer.

[0014] A further improvement of the present invention is that the surfaces of the first column of channels, the second column of channels and the third column of channels, as well as the inner surfaces of the blade cover corresponding to the three columns of channels are arranged with spoiler structures; a fifth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer is arranged on the surface of each spoiler structure, and a twenty-fifth electrode sheet and a twenty-eighth electrode sheet are arranged between the surface of the spoiler structure and the fifth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer.

[0015] A further improvement of the present invention is that a sixth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer is arranged at the rounded corners of the outer walls of the first turning area and the second turning area, and twenty-ninth to thirty-first electrode sheets are arranged between the outer rounded corner wall and the sixth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer.

[0016] A control method for a combustion turbine blade mid-chord cooling structure with multi-position joint adjustment includes the following steps:

[0017] 1) According to the cooling requirements of the blade, the total outflow area of ​​the top outflow hole A and the top outflow hole B is proportionally adjusted, and the shape of the turbulent structure is adjusted in batches to achieve rapid coarse adjustment of the cooling gas flow rate and rapid matching of the channel resistance;

[0018] 2) Based on the average temperature difference between the first, second, and third columns of channels, the area ratio of the top outlet holes A and B is adjusted to achieve rapid and rough adjustment of the gas distribution between the channels;

[0019] 3) According to the flow conditions between adjacent channels, adjust the openings of connecting bridges A, B, C, D, E, and F to eliminate obvious flow separation in each channel and achieve precise and fine-tuned flow between channels;

[0020] 4) Based on the flow conditions in the front and rear positions of the first and second turning areas, as well as the cooling requirements at the top position, the thickness and profile of guide vanes A and B are adjusted, and the curvatures of the first outer fillet of the first turning area, the second outer fillet of the first turning area, the first outer fillet of the second turning area, and the second outer fillet of the second turning area are jointly adjusted to eliminate flow separation in front and behind the turning areas, change the heat transfer performance of the top area, and achieve precise and fine-tuning of the flow and cooling in the turning areas;

[0021] 5) According to the average temperature difference between the pressure and suction sides of the blade, the flow cross-sectional shapes of connecting bridges A, B, C, D, E, and F are adjusted to change the offset state of the cooling gas along the thickness direction of the blade, thereby achieving rapid and rough cooling of the pressure and suction sides;

[0022] 6) Based on the local high temperature that still exists in the mid-chord area of ​​the blade, the shape of the turbulence structure in the corresponding area is adjusted to enhance the local heat exchange capacity and achieve local precise fine-tuning of the high-temperature area of ​​the blade.

[0023] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0024] 1. The present invention arranges high-temperature resistant, low-thermal-resistance flexible electro-sensitive layers and electrode sheets on the surfaces of multiple cooling channel structures. By adjusting the voltage of the electrode sheets, the thickness of the high-temperature resistant, low-thermal-resistance flexible electro-sensitive layers near the electrode sheets is changed, thereby realizing the flow structure adjustment functions such as adjustable flow area of ​​the top outflow hole, adjustable thickness and profile of the guide vane in the turning area, adjustable curvature of the rounded corners of the outer wall of the turning area, adjustable flow opening and cross-sectional shape of the connecting bridge, and adjustable shape of the local spoiler structure. Therefore, it has two significant advantages: ① The present invention only needs to simply adjust the thickness of the high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer to change the flow structure at each position. Without replacing the test piece, different flow structure forms and their geometric parameters, as well as the influence of the combined effect of multiple parts of the structure on the blade cooling performance, can be achieved, and the blade cooling design optimization scheme can be quickly obtained, which solves the problems of a large number of different structural test pieces required for traditional cooling structure design optimization, high cost of overall replacement of test pieces, and long test optimization cycle; ② It has good universality and is widely applicable to gas turbine blades with different profiles and internal cooling channels. By adjusting the structure of each part, it can ensure that the blade has good comprehensive performance;

[0025] 2. When the gas turbine is operating under variable operating conditions, the multi-position joint adjustment method of the mid-chord cooling channel proposed in the present invention can realize a series of functions such as rapid coarse adjustment of the cooling gas flow rate and rapid matching of the channel resistance, rapid coarse adjustment of the air distribution between channels and precise fine adjustment of the flow, precise fine adjustment of the flow and cooling in the turning area, rapid coarse adjustment of the cooling of the pressure surface and suction surface, and local precise fine adjustment of the high-temperature area of ​​the blade. It can quickly adapt to the cooling needs of the blade and changes in the flow and heat transfer characteristics, and ultimately accurately adjust to the cooling solution with optimal cooling performance, minimum resistance loss, and best temperature uniformity.

[0026] 3. The present invention provides a multi-position jointly regulated mid-chord cooling structure for combustion turbine blades, which splits the blade into two parts: the blade body and the blade cover plate. This solves the problem that blades with long and complex cooling channels can only be cast. The blade processing can be completed by milling, which greatly reduces the difficulty and cost of blade processing on the one hand, and improves the processing accuracy on the other hand. In addition, the split design also reduces the difficulty of arranging the internal high-temperature resistant, low-thermal resistance, high-temperature resistant, low-thermal resistance flexible electrosensitive layer and electrode sheet, and can also solve the problem of sensor arrangement inside the combustion turbine blade. In particular, a multi-step ladder structure is provided between the blade body and the blade cover plate to reduce the leakage of the internal cooling medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the blade body structure of the present invention;

[0028] Figure 2 This is a side view of the pressure surface of the blade body of the present invention;

[0029] Figure 3 This is a schematic diagram of the blade cover structure of the present invention, wherein Figure 3 (a) is the outer side view of the cover. Figure 3 (b) is the inner side view of the cover. Figure 3 (c) is a partially enlarged schematic diagram of the multi-step structure;

[0030] Figure 4 Schematic diagram of the flow area adjustment of the top outflow hole of the present invention, wherein Figure 4 (a) is a cross-sectional view of the top of the blade body. Figure 4 (b) is a cross-sectional view of the top outlet hole with a large flow area. Figure 4 (c) is a cross-sectional view of the top outlet hole with a small flow area;

[0031] Figure 5 The thickness and profile adjustment diagram of the guide vane of the present invention is shown in FIG. Figure 5 (a) is a cross-sectional view of the thin guide vane structure. Figure 5 (b) is a cross-sectional view of the thick guide vane structure. Figure 5 (c) is a cross-sectional view of the airfoil guide vane structure;

[0032] Figure 6 Schematic diagram of the flow opening and cross-sectional shape adjustment of the connecting bridge of the present invention, wherein Figure 6 (a) is a schematic diagram of the AA section position, Figure 6 (b) is the AA section view of the blade body. Figure 6 (c) Cross-sectional view of the connecting bridge structure with different flow openings and cross-sectional shapes;

[0033] Figure 7 Schematic diagram of the shape adjustment of the spoiler structure of the present invention, wherein Figure 7(a) is a schematic diagram of the position of the electrode piece of the spoiler structure on the blade cover. Figure 7 (b) is a schematic diagram of the position of the electrode piece of the spoiler structure on the blade body. Figure 7 (c) is a cross-sectional view of spoiler structures of different shapes;

[0034] Figure 8 Schematic diagram of the curvature adjustment of the outer rounded corner of the turning area of ​​the present invention, wherein Figure 8 (a) is a schematic diagram of the outer rounded corner structure of the first turning area. Figure 8 (b) is a schematic diagram of the rounded corner structure outside the second turning area. Figure 8 (c) is a cross-sectional view of the outer corner structure of the turning area with different turning curvatures;

[0035] Description of reference numerals:

[0036] 1 is the blade body, 2 is the top outflow hole A, 3 is the top outflow hole B, 4 is the connecting bridge A, 5 is the connecting bridge B, 6 is the connecting bridge C, 7 is the connecting bridge D, 8 is the connecting bridge E, 9 is the connecting bridge F, 10 is the guide vane A, 11 is the guide vane B, 12 is the spoiler structure, 13 is the blade cover, 14 is the threaded hole, 15 is the multi-step structure, H1 is the through hole, P1 is the first column of channels, P2 is the second column of channels, P3 is the third column of channels, T1 is the first turning area, T2 is the second turning area, RD1-RD6 are the first high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer to the sixth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer, E1-E31 are the first electrode sheet to the thirty-first electrode sheet, T1F1 is the first rounded corner outside the first turning area, T1F2 is the second rounded corner outside the first turning area, T2F1 is the first rounded corner outside the second turning area, and T2F2 is the second rounded corner outside the second turning area. DETAILED DESCRIPTION

[0037] The following describes an embodiment of the present invention in detail with reference to the accompanying drawings. This embodiment is based on the technical solution of the present invention and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiment.

[0038] like Figure 1 and Figure 2As shown, the present invention provides a multi-position jointly adjusted combustion turbine blade mid-chord cooling structure, including a blade body 1 and a blade cover plate 13, wherein the top of the blade body 1 is arranged with a top outflow hole A2 and a top outflow hole B3, and a cavity structure is provided inside the blade body 1. The cavity structure is blocked by a channel partition to form a cooling medium channel. The cooling medium channel can be isolated into multiple flow channels according to actual conditions. In this embodiment, it is a three-flow serpentine cooling channel. During operation, the cooling medium flows into the bottom of the blade body 1, passes through the first column of channels P1, and reaches the first turning area T1. Part of the cooling medium flows out of the top outlet A2, while the remaining medium flows through the second row of channels P2, the second turning area T2, and the third row of channels P3 before flowing out of the top outlet B3. The channel partitions between the first and second rows of channels P1 and P2 are equipped with connecting bridges A4, B5, and C6, while the channel partitions between the second and third rows of channels P2 and P3 are equipped with connecting bridges D7, E8, and F9. Guide vanes A10 are arranged in the first turning area T1, and guide vanes B11 are arranged in the second turning area T2. Flow-turbulating structures 12 are arranged on the surfaces of the first, second, and third rows of channels P1, P2, and P3, as well as on the inner surfaces of the blade cover 13 corresponding to the three rows of channels. These flow-turbulating structures can be any channel surface heat exchange enhancement structure, such as ribs, sockets, or protrusions. In this embodiment, a socket structure is used.

[0039] like Figures 1 to 3 As shown, the surface of the blade body 1 is provided with a plurality of threaded holes 14, and the surface of the blade cover plate 13 is provided with a plurality of through-holes H1. During assembly, countersunk screws are passed through the through-holes H1 on the blade cover plate 13 and screwed into the threaded holes 14 on the surface of the blade body 1 to connect the blade body 1 to the blade cover plate 13. Decomposing the blade into two parts, the blade body 1 and the blade cover plate 13, not only reduces the difficulty of blade processing, but also facilitates the arrangement of the first electrode sheet E1 to the thirty-first electrode sheet E31 and the first high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD1 to the sixth high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD6 within the blade. Furthermore, to ensure a tight connection between the blade body 1 and the blade cover plate 13, a multi-step stepped structure 15 is provided at the connection between the blade body 1 and the blade cover plate 13, which significantly reduces leakage of the cooling medium at the connection.

[0040] like Figure 1 、 Figure 2 and Figure 4As shown, the first high-temperature resistant low-thermal-resistance flexible electro-sensitive layer RD1 and the second high-temperature resistant low-thermal-resistance flexible electro-sensitive layer RD2 are respectively arranged inside the top outflow hole A2 and the top outflow hole B3, the first electrode sheet E1 to the fourth electrode sheet E4 are arranged between the first high-temperature resistant low-thermal-resistance flexible electro-sensitive layer RD1 and the blade body 1, and the fifth electrode sheet E5 to the eighth electrode sheet E8 are arranged between the second high-temperature resistant low-thermal-resistance flexible electro-sensitive layer RD2 and the blade body 1 inside the top outflow hole B3. The first high-temperature resistant low-thermal-resistance flexible electro-sensitive layer RD1 and the second high-temperature resistant low-thermal-resistance flexible electro-sensitive layer RD2 can expand and contract according to the voltage of the first electrode sheet E1 to the eighth electrode sheet E8. During operation, the thickness of the first high-temperature-resistant, low-thermal-resistance flexible electrosensitive layer RD1 on the surface of top outlet hole A2 can be controlled by controlling the voltage across the first electrode E1 through the fourth electrode E4, thereby controlling the flow area of ​​top outlet hole A2. The thickness of the second high-temperature-resistant, low-thermal-resistance flexible electrosensitive layer RD2 on the surface of top outlet hole B3 can be controlled by controlling the voltage across the fifth electrode E5 through the eighth electrode E8, thereby controlling the flow area of ​​top outlet hole B3. By adjusting the flow area ratio between top outlet holes A2 and B3, the flow rate of the coolant flowing out of these two holes can be adjusted, thereby adjusting the flow distribution within different channels of the blade in real time. This addresses the issue of blade thermal load variations caused by variable operating conditions. This not only avoids cooling air loss due to excess cooling air flow and component overheating due to insufficient cooling air flow, but also reduces temperature differences between channels, improving overall blade temperature uniformity, reducing thermal stress caused by expansion differences, and enhancing blade safety.

[0041] like Figure 1 、 Figure 2 and Figure 5 As shown, both guide vane A10 and guide vane B11 have a third high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD3 arranged on their surfaces. The following description uses the structure of guide vane A10 as an example; the structure of guide vane B11 is similar. In this embodiment, ninth and twentieth electrode sheets E9 and E20 are arranged between the surface of guide vane A10 and the third high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD3. During operation, the thickness of the third high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD3 on the surface of guide vane A10 can be controlled by controlling the voltage of the ninth and twentieth electrode sheets E9 and E20, thereby varying the thickness and profile of guide vane A10. The turbulent flow of coolant in the turning area and the impact of the turning flow on the downstream channel are among the main causes of significant channel resistance loss. Providing a guide vane structure with variable thickness and profile in the turning area can significantly reduce channel pressure loss and significantly improve cooling performance at the top of the turning area, thereby enhancing the overall cooling performance of the channel.

[0042] like Figure 1 、 Figure 2 and Figure 6 As shown, the surfaces of the channel baffles' connecting bridges A4, B5, C6, D7, E8, and F9 are all coated with a fourth high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD4. The following description uses connecting bridge D7 as an example; the structures of the remaining connecting bridges are similar. In this embodiment, the twenty-first through twenty-fourth electrode sheets E21, E24, are positioned between the surface of connecting bridge D7 and the fourth high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD4. By controlling the voltage across the twenty-first through twenty-fourth electrode sheets E21, E24, the thickness of the fourth high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD4 on the surface of connecting bridge D7 can be controlled to alter the flow opening and cross-sectional shape of connecting bridge D7. The entire blade cooling channel features multiple functions, including adjustable number and position of connecting bridges, adjustable flow distribution between connecting bridges, and adjustable flow offset at each connecting bridge. This solves the problems of local heat transfer deterioration and thermal stress concentration caused by the following two factors: on the one hand, the heat loads borne by the blades along the chord length and blade height directions are different, and the cooling requirements of each area are different; on the other hand, when the blades are rotating, the cooling medium is affected by the rotating Coriolis force, often showing flow deviation characteristics, and there are huge differences in heat transfer between different wall surfaces.

[0043] like Figure 1 、 Figure 3 and Figure 7As shown, the surfaces of the first column of channels P1, the second column of channels P2, and the third column of channels P3, as well as the inner surfaces of the three corresponding columns of channels on the blade cover 13, are all provided with a flow-turbine structure 12. To improve the surface heat transfer level of the chord cooling channel of the combustion turbine blade, flow-turbine structures such as ribs, sockets, and protrusions are usually provided on the heat transfer surface. However, flow-turbine structures also cause additional pressure loss, and under different operating conditions, ribs of different heights and sockets and protrusions of different depths should be selected. In this embodiment, the flow-turbine structure 12 having a socket structure is used as an example for explanation. A fifth high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD5 is provided on the surface of each flow-turbine structure 12, and twenty-fifth to twenty-eighth electrode sheets E25 to E28 are provided between the surface of the flow-turbine structure 12 and the fifth high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD5. When the engine is operating at low load, the cooling medium flow rate is low. At this time, the voltage of the 25th electrode sheet E25 to the 28th electrode sheet E28 can be adjusted to control the thickness of the fifth high-temperature-resistant, low-thermal-resistance flexible electrosensitive layer RD5 on the surface of the spoiler structure 12, reducing the depth of the ball-socket structure to reduce pressure loss in the channel. When the engine is operating at high load, a large amount of cooling medium is required to reduce the temperature of the engine blades and ensure safe and stable operation of the engine. At this time, the voltage of the 25th electrode sheet E25 to the 28th electrode sheet E28 can be adjusted to control the thickness of the fifth high-temperature-resistant, low-thermal-resistance flexible electrosensitive layer RD5 on the surface of the ball-socket structure, increasing the depth of the ball-socket structure to enhance the heat transfer capacity of the channel. Therefore, in actual operation, the shape of the spoiler structure 12 can be adjusted in batches to balance the heat transfer capacity and pressure loss of the turbine blade midchord cooling channel, thereby ensuring that the turbine blade midchord cooling structure achieves good overall performance under all operating conditions. In particular, by precisely adjusting the shape of the spoiler structure 12 at different locations, fine-tuning of the temperature distribution can be achieved, avoiding thermal stress problems caused by temperature unevenness.

[0044] like Figure 1 、 Figure 2 and Figure 8As shown, the sixth high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD6 is disposed at the rounded corners of the outer walls of both the first turning region T1 and the second turning region T2, and the twenty-ninth electrode sheet E29 to the thirty-first electrode sheet E31 are disposed between the outer rounded corner wall and the sixth high-temperature-resistant, low-thermal-resistance flexible electro-sensitive layer RD6. After the coolant passes through the turning region, it often exhibits a turbulent flow state under the action of centrifugal force, thereby reducing the heat exchange capacity within the next column of channels. The following description takes the second rounded corner T2F2 outside the second turning region as an example, and the other rounded corners are similar. In this embodiment, the thickness of the second rounded corner T2F2 outside the second turning region can be controlled by changing the voltage of the twenty-ninth electrode sheet E29 to the thirty-first electrode sheet E31, thereby changing the curvature of the turning angle, thereby controlling the angle and flow state of the coolant entering the third column of channels P3. When the gas turbine operates under different working conditions, the flow rate and flow state of the cooling medium inside the channel are different. By adjusting the thickness of the outer wall fillet of the first turning area T1 and the second turning area T2, the flow state of the cooling medium inside the second column of channels P2 and the third column of channels P3 can be improved, thereby improving the heat transfer performance inside the second column of channels P2 and the third column of channels P3 and reducing the resistance loss in the channel.

[0045] When the gas turbine is operating under variable operating conditions, the cooling requirements and flow heat transfer characteristics of the blades change. Based on the above-mentioned channel cooling structure and local control method, the present invention has the following multi-position joint adjustment method for the mid-chord cooling channel:

[0046] 1) According to the blade cooling requirements, the total outflow area of ​​the top outflow hole A2 and the top outflow hole B3 is proportionally adjusted, and the shape of the flow-turbine structure 12 is adjusted in batches to achieve rapid coarse adjustment of the cooling gas flow rate and rapid matching of the channel resistance;

[0047] 2) Based on the average temperature difference between the first column of channels P1, the second column of channels P2, and the third column of channels P3, the area ratio of the top outlet holes A2 and the top outlet holes B3 is adjusted to achieve rapid and rough adjustment of the gas distribution between the channels;

[0048] 3) According to the flow conditions between adjacent channels, adjust the openings of connecting bridges A4, B5, C6, D7, E8, and F9 to eliminate obvious flow separation in each channel and achieve precise and fine-tuned flow between channels;

[0049] 4) Based on the flow conditions before and after the first turning area T1 and the second turning area T2, as well as the cooling requirements at the top, the thickness and profile of the guide vanes A10 and B11 are adjusted, and the curvatures of the first outer corner T1F1 of the first turning area, the second outer corner T1F2 of the first turning area, the first outer corner T2F1 of the second turning area, and the second outer corner T2F2 of the second turning area are jointly adjusted to eliminate flow separation before and after the turning areas, change the heat transfer performance of the top area, and achieve precise and fine-tuning of the flow and cooling in the turning areas.

[0050] 5) According to the average temperature difference between the pressure and suction sides of the blade, the flow cross-sectional shapes of connecting bridges A4, B5, C6, D7, E8, and F9 are adjusted to change the offset state of the cooling gas along the thickness direction of the blade, thereby achieving rapid and rough cooling of the pressure and suction sides;

[0051] 6) According to the local high temperature that still exists in the mid-chord area of ​​the blade, the shape of the turbulent structure 12 in the corresponding area is adjusted to enhance the local heat exchange capacity and achieve local precise fine adjustment of the high temperature area of ​​the blade.

[0052] In summary, the present invention arranges high-temperature-resistant, low-thermal-resistance flexible electrosensitive layers and electrode sheets on the various structural surfaces within the chord cooling channel of the gas turbine blade. This allows the channel to have better overall performance even for gas turbine blades with different profiles by jointly adjusting the internal cooling structural parameters. When the gas turbine unit is operating under variable operating conditions, the heat transfer level and resistance performance of the channel can be improved by jointly adjusting multiple locations within the cooling channel, thereby reducing the thermal stress and resistance loss of the gas turbine blade. Furthermore, the multi-location adjustable structure of the present invention also helps save time and cost in testing the internal cooling structure of gas turbine blades, reduces the difficulty of blade processing and internal sensor placement, and has considerable economic benefits.

[0053] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A multi-position joint adjustment combustion turbine blade mid-chord cooling structure, characterized in that: comprising a blade body and a blade cover; A top outflow hole A and a top outflow hole B are arranged at the top of the blade body, and a cavity structure is provided inside the blade body. The cavity structure is blocked by a channel partition to form a cooling medium channel. The cooling medium channel is a multi-flow channel. When it is a three-flow serpentine cooling channel, the cooling medium flows in from the bottom of the blade body during operation, passes through the first column of channels and reaches the first turning area. Part of the cooling medium flows out from the top outflow hole A, and the rest flows out from the top outflow hole B after passing through the second column of channels, the second turning area and the third column of channels respectively; the channel partition between the first column of channels and the second column of channels is provided with a connecting bridge A, a connecting bridge B and a connecting bridge C, and the channel partition between the second column of channels and the third column of channels is provided with a connecting bridge D, a connecting bridge E and a connecting bridge F; a guide vane A is provided in the first turning area, and a guide vane B is provided in the second turning area; a turbulent flow structure is provided on the surface of the first column of channels, the second column of channels and the third column of channels, as well as on the inner surface of the blade cover corresponding to the three columns of channels, and the turbulent flow structure is a rib, a ball socket and a ball-convex channel surface enhanced heat exchange structure; Arranging the first electrode sheet to the thirty-first electrode sheet and the first high-temperature-resistant low-thermal-resistance flexible electro-sensitive layer to the sixth high-temperature-resistant low-thermal-resistance flexible electro-sensitive layer inside the blade; The first high-temperature resistant and low-thermal resistance flexible electro-sensitive layer and the second high-temperature resistant and low-thermal resistance flexible electro-sensitive layer are respectively arranged inside the top outflow hole A and the top outflow hole B. The first electrode sheet to the fourth electrode sheet are arranged between the first high-temperature resistant and low-thermal resistance flexible electro-sensitive layer and the blade body. The fifth electrode sheet to the eighth electrode sheet are arranged between the second high-temperature resistant and low-thermal resistance flexible electro-sensitive layer and the blade body inside the top outflow hole B.

2. The multi-position jointly adjusted combustion turbine blade mid-chord cooling structure according to claim 1, characterized in that: The connection between the blade body and the blade cover is arranged with a multi-step structure.

3. The multi-position jointly adjusted combustion turbine blade mid-chord cooling structure according to claim 1, characterized in that: There are multiple threaded holes on the surface of the blade body and multiple through holes on the surface of the blade cover. During assembly, the countersunk screws are passed through the through holes on the blade cover and screwed into the threaded holes on the surface of the blade body to connect the blade body and the blade cover.

4. The multi-position jointly adjusted combustion turbine blade mid-chord cooling structure according to claim 1, characterized in that: The surfaces of guide vane A and guide vane B are both provided with a third high-temperature resistant, low-thermal-resistance flexible electro-sensitive layer, and the ninth to twentieth electrode sheets are arranged between the surface of guide vane A and the third high-temperature resistant, low-thermal-resistance flexible electro-sensitive layer.

5. The multi-position jointly adjusted combustion turbine blade mid-chord cooling structure according to claim 1, characterized in that: The surfaces of the connecting bridges A, B, C, D, E and F of the channel partition are all arranged with a fourth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer, and the twenty-first to twenty-fourth electrode sheets are arranged between the surface of the connecting bridge D and the fourth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer.

6. The multi-position jointly adjusted combustion turbine blade mid-chord cooling structure according to claim 1, characterized in that: The surfaces of the first column of channels, the second column of channels and the third column of channels, as well as the inner surfaces of the three columns of channels corresponding to the blade cover are arranged with spoiler structures; the fifth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer is arranged on the surface of each spoiler structure, and the twenty-fifth electrode sheet and the twenty-eighth electrode sheet are arranged between the surface of the spoiler structure and the fifth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer.

7. The multi-position jointly adjusted combustion turbine blade mid-chord cooling structure according to claim 1, characterized in that: The sixth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer is arranged at the rounded corners of the outer walls of the first turning area and the second turning area, and the twenty-ninth to thirty-first electrode sheets are arranged between the outer rounded corner wall and the sixth high-temperature resistant and low-thermal-resistance flexible electro-sensitive layer.

8. A control method for a combustion turbine blade mid-chord cooling structure with multi-position joint adjustment according to any one of claims 1 to 7, characterized in that: The following steps are involved: 1) According to the cooling requirements of the blade, the total outflow area of ​​the top outflow hole A and the top outflow hole B is proportionally adjusted, and the shape of the turbulent structure is adjusted in batches to achieve rapid coarse adjustment of the cooling gas flow rate and rapid matching of the channel resistance; 2) Based on the average temperature difference between the first, second, and third columns of channels, the area ratio of the top outlet holes A and B is adjusted to achieve rapid and rough adjustment of the gas distribution between the channels; 3) According to the flow conditions between adjacent channels, adjust the openings of connecting bridges A, B, C, D, E, and F to eliminate obvious flow separation in each channel and achieve precise and fine-tuned flow between channels; 4) Based on the flow conditions in the front and rear positions of the first and second turning areas, as well as the cooling requirements at the top position, the thickness and profile of guide vanes A and B are adjusted, and the curvatures of the first outer fillet of the first turning area, the second outer fillet of the first turning area, the first outer fillet of the second turning area, and the second outer fillet of the second turning area are jointly adjusted to eliminate flow separation in front and behind the turning areas, change the heat transfer performance of the top area, and achieve precise and fine-tuning of the flow and cooling in the turning areas; 5) According to the average temperature difference between the pressure and suction sides of the blade, the flow cross-sectional shapes of connecting bridges A, B, C, D, E, and F are adjusted to change the offset state of the cooling gas along the thickness direction of the blade, thereby achieving rapid and rough cooling of the pressure and suction sides; 6) Based on the local high temperature that still exists in the mid-chord area of ​​the blade, the shape of the turbulence structure in the corresponding area is adjusted to enhance the local heat exchange capacity and achieve local precise fine-tuning of the high-temperature area of ​​the blade.

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