Honeycomb cross rib cooling structure for tail edge of turbine blade

Abstract

The invention discloses a honeycomb cross rib cooling structure for the trailing edge of a turbine blade, the structure comprises a suction surface, a pressure surface, a crack cavity and honeycomb cross ribs, the suction surface and the pressure surface are opposite in position, the crack cavity is formed between the suction surface and the pressure surface, the honeycomb cross ribs are arranged in the crack cavity, and the honeycomb cross ribs ensure that cooling gas fully exchanges heat; and the honeycomb cross ribs are high in structural strength, so that the structural strength is improved at the thin layer of the trailing edge.

Description

Technical Field

[0001] The invention belongs to the technical field of gas turbine blade cooling and relates to a honeycomb cross-rib cooling structure for the trailing edge of a turbine blade. Background Art

[0002] As an advanced power device, gas turbines are widely used in power generation, aviation propulsion, chemical industry and other fields. At present, the turbine inlet temperature of heavy-duty gas turbines far exceeds the melting point of their materials, and turbine blades usually require complex thermal protection designs to ensure the normal operation of the blades at such high temperatures.

[0003] The trailing edge structure of turbine blades is relatively thin, and the pressure side of the trailing edge bears a large heat load and structural strength. A column rib structure is usually used to enhance heat exchange. The column rib structure connects the two side end walls, namely the pressure side and the suction side, to disturb the incoming cold air. The cold air flows through the column ribs, and the horseshoe vortex system formed by the stagnation in front of the rib column enhances the heat exchange of the two side end walls. The unstable vortex shedding on the rear side of the column rib also increases the turbulence of the internal flow, enhancing the heat exchange in the front area of ​​the trailing edge. While enhancing the heat exchange of the internal cooling channel, the column ribs also play a certain supporting role for the thinner trailing edge of the blade, enhancing the strength of the trailing edge of the blade. The pressure difference between the pressure side and the suction side of the turbine blade is large. The cold air at the trailing edge oblique split seam often ejects out of the trailing edge before sufficient heat exchange in the inner cooling zone, which reduces the overall cooling efficiency. The problem of geothermal stress caused by uneven cooling of the blade is more prominent.

[0004] In order to cope with the increasing turbine inlet temperature and limited cooling air flow, a blade trailing edge structure with efficient cooling is urgently needed. Summary of the invention

[0005] In order to overcome the above-mentioned problems, the present invention proposes a honeycomb cross-rib cooling structure for the trailing edge of a turbine blade, wherein the cooling structure comprises a suction surface, a pressure surface, a cleavage cavity and honeycomb cross ribs, wherein the suction surface and the pressure surface are positioned opposite to each other to form a cleavage cavity, wherein honeycomb cross ribs are arranged in the cleavage cavity, and the honeycomb cross ribs ensure sufficient heat exchange of the cooling gas, and the honeycomb cross rib structure has high strength, thereby improving its structural strength at the thin layer at the trailing edge.

[0006] Specifically, the purpose of the present invention is to provide the following aspects: In a first aspect, a trailing edge slit cooling structure is provided, the structure comprising: a suction surface, a pressure surface, a slit cavity and honeycomb cross ribs, the suction surface and the pressure surface are positioned opposite to each other to form a slit cavity therebetween, and a honeycomb cross rib is arranged in the slit cavity.

[0007] The slit cavity is used to contain cooling gas and guide its flow.

[0008] Among them, the honeycomb cross ribs are used to increase the turbulence of the cooling gas, thereby promoting heat transfer.

[0009] Wherein, a part of the pressure surface is removed to form a trailing edge half-slit structure.

[0010] Wherein, on the suction surface, a trailing edge split outlet surface is provided at a position corresponding to the trailing edge half split structure of the pressure surface.

[0011] Wherein, the trailing edge slit outlet surface is used to guide the cooling gas to spray out and form a cooling gas film.

[0012] Wherein, the edge of the exit surface of the trailing edge split seam is set as a chamfer or a rounded corner.

[0013] Wherein, the honeycomb cross ribs are separated by trailing edge split cross ribs.

[0014] Wherein, the trailing edge split transverse rib is used to guide the flow direction of the cooling gas.

[0015] In a second aspect, a method for cooling the trailing edge split of a turbine blade is provided, wherein the cooling structure described in the first aspect is used to cool the trailing edge split.

[0016] In a third aspect, a turbine blade trailing edge slit cooling device is provided, the device comprising the cooling structure described in the first aspect.

[0017] The beneficial effects of the present invention include: (1) The trailing edge split cooling structure provided by the present invention comprises a suction surface, a pressure surface and a trailing edge split transverse rib, which together form a fixed structure to guide the flow direction of the cooling gas. The structure cooperates with the honeycomb cross ribs to ensure that the cooling gas can fully exchange heat in the complex honeycomb cross rib structure. The honeycomb cross rib structure has high strength, which improves its structural strength at the trailing edge thin layer. (2) The trailing edge split cooling structure provided by the present invention changes the front inner cooling structure of the trailing edge split into a honeycomb cross rib. The complex flow path of the cold air increases the heat transfer coefficient in the trailing edge split, giving full play to the heat transfer performance of the front inner cooling structure, thereby improving the cooling efficiency. (3) The trailing edge slit cooling structure provided by the present invention achieves precise control of the structural strength and heat exchange requirements under different working conditions by adjusting the number of layers, size, shape and arrangement of the honeycomb cross ribs, which is of great significance in practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only used to illustrate the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work.

[0019] In the attached picture: FIG1 (a) shows a schematic diagram of a trailing edge split cooling structure according to a preferred embodiment of the present invention; FIG1( b ) shows a simplified cooling gas flow diagram of the trailing edge split cooling structure; Figure 2 A rib cooling gas flow diagram is shown; Figure 3 A front view of FIG. 1 (a) is shown; FIG4( a ) shows a top view of a single rib layer; FIG4( b ) shows a top view of FIG1( a ); FIG5( a ) shows a top view of the trailing edge slit cooling structure of Comparative Example 1; FIG5( b ) shows a simplified schematic diagram of the trailing edge split cooling structure of Comparative Example 1; FIG6 (a) shows a cooling efficiency distribution diagram of the trailing edge split cooling structure in Comparative Example 1; FIG6( b ) shows a cooling efficiency distribution diagram of the trailing edge split cooling structure in Example 1; Figure 7 A comparison diagram of cooling efficiency between Example 1 and Comparative Example 1 is shown; BRIEF DESCRIPTION OF THE DRAWINGS 1-Suction surface; 2-pressure surface; 3- Honeycomb cross ribs; 4- caudal edge split transverse rib; 5-Split cavity; 6- tail edge split exit surface; 7-upper rib; 8-lower rib; 9-unit honeycomb ribs; 10-Comparative suction surface; 11-Comparative pressure surface; 12-Comparative cylinder; 13-Comparative example split cavity; 14-Comparative example of split seam exit surface. DETAILED DESCRIPTION

[0020] The following will refer to Figures 1(a) to Figure 7 Specific embodiments of the present invention are described in more detail. Although specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0021] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", etc. indicate positions or positional relationships based on the working state of the present invention, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0023] To facilitate understanding of the embodiments of the present invention, further explanation will be given below by taking specific embodiments as examples in conjunction with the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0024] On the one hand, according to the present invention, there is provided a trailing edge slit cooling structure, as shown in FIGS. 1( a) to 4( b), the structure comprising: a suction surface 1, a pressure surface 2, a slit cavity 5 and honeycomb cross ribs 3, wherein the suction surface 1 and the pressure surface 2 are positioned opposite to each other to form a slit cavity 5 therebetween, and a honeycomb cross rib 3 is provided in the slit cavity 5.

[0025] Furthermore, the slit cavity 5 is used to accommodate cooling gas and guide its flow; the honeycomb cross ribs 3 are used to increase the turbulence of the cooling gas, thereby promoting heat transfer.

[0026] In the present invention, as shown in FIG1 (a), the pressure surface 2 is one side of the trailing edge slit cooling structure, and a portion of its wall surface is removed to form a trailing edge half-slit structure. The inner wall edge of the pressure surface 2 (the right inner wall edge along the cooling gas flow direction) is set to be rounded to improve the quality of air film formation.

[0027] In the present invention, the lip thickness of the pressure surface 2 is D, which is usually 3-5 mm, for example 4 mm.

[0028] Among them, the thickness of the pressure surface 2 lip will affect the flow characteristics of the airflow. In order to reduce airflow separation and loss, improve turbine efficiency, and ensure sufficient structural strength and thermal resistance to prevent deformation or damage, 3~5mm is more appropriate.

[0029] In the present invention, the suction surface 1 is the other side of the trailing edge split cooling structure. On the suction surface 1, a trailing edge split outlet surface 6 is provided at a position corresponding to the trailing edge half split structure of the pressure surface 2. A trailing edge split outlet is formed at the position corresponding to the trailing edge half split structure. The trailing edge split outlet surface 6 forms an outlet angle α with the pressure surface 2. The outlet angle α is 5~20°, for example 20°.

[0030] Furthermore, the trailing edge slit outlet surface 6 is used to guide the cooling gas to eject and form a cooling gas film. The horizontal distance S4 between the tail end of the trailing edge slit outlet surface 6 and the tail end of the pressure surface 2 is 4-8D, for example, 5.85D; it can also be understood that the length S4 of the trailing edge slit outlet is 4-8D, for example, 5.85D.

[0031] Among them, the horizontal distance S4 between the tail end of the trailing edge split outlet surface 6 and the tail end of the pressure surface 2 affects the flow path and heat exchange efficiency of the cooling gas at the trailing edge split outlet surface 6. As the horizontal distance S4 is extended, the outlet area increases, the flow resistance decreases, and the cooling efficiency improves; but if the horizontal distance S4 is too long, on the one hand, it will cause the trailing edge structure to be excessively hollowed out and the structural strength to be reduced. On the other hand, the long distance cold air is easy to leave the surface of the trailing edge split outlet surface 6, and the cooling efficiency is reduced.

[0032] In the present invention, the size of the outlet angle α affects the injection angle of the cooling gas, and further affects the film cooling effect. When the outlet angle α is 5-20°, it can ensure that the cooling gas forms a uniform film on the trailing edge split outlet surface 6, effectively isolating the high-temperature combustion gas.

[0033] In the present invention, the edge of the trailing edge split outlet surface 6 is chamfered or rounded to reduce stress concentration in fluid dynamics and improve the quality of air film formation.

[0034] In the present invention, the thickness at the exit surface 6 of the trailing edge slit is usually consistent with the thickness of the pressure surface 2, both being D.

[0035] In the present invention, the structure of the suction surface 1 is not strictly limited and is related to the structure of the turbine blade.

[0036] In one embodiment, if Figure 3 As shown, the front view of the trailing edge split cooling structure, namely the suction surface 1 and the pressure surface 2, is quasi-triangular. The pressure surface 2 is above the horizontal position of the suction surface 1.

[0037] In the present invention, the honeycomb cross ribs 3 are separated by the trailing edge split transverse ribs 4, or in other words, the honeycomb cross ribs 3 are located between the trailing edge split transverse ribs 4 and in the split cavity 5 between the pressure surface 2 and the suction surface 1; the trailing edge split transverse ribs 4 are used to guide the flow direction of the cooling gas and strengthen the trailing edge structural strength.

[0038] In the present invention, the upper end of the trailing edge split transverse rib 4 is in close contact with the pressure surface 2, and the lower end is in close contact with the suction surface 1. The cross-sectional dimension of the trailing edge split transverse rib 4 along the flow direction of the cooling gas is consistent with the cross-sectional dimension of the split cavity 5, that is, the portion of the trailing edge split transverse rib 4 in close contact with the pressure surface 2 is rectangular along the flow direction of the cooling gas, and the portion corresponding to the trailing edge half split structure of the pressure surface 2 is in a triangular shape along the flow direction of the cooling gas, and the top end is flush with the surface of the pressure surface 2.

[0039] Preferably, the distance S5 between the trailing edge split cross rib 4 and the cold air inlet (the left end of the pressure surface 2 or the left end of the suction surface 1) is 2-4D, for example, 2.5D, so that the front cold air evenly flushes the trailing edge split cooling structure.

[0040] In the present invention, the thickness H of the trailing edge split transverse rib 4 is 0.25~1D, for example 0.5D. A certain thickness of the trailing edge split transverse rib 4 can enhance the structural strength of the trailing edge. Too large a thickness H will increase the cold air flow resistance and reduce the cooling efficiency.

[0041] Furthermore, the distance P between the trailing edge split transverse ribs 4 is 5-8D, for example 6.5D, to ensure that there is at least one complete unit honeycomb rib 9 perpendicular to the airflow direction, thereby achieving efficient cooling and enhancing structural strength.

[0042] In the present invention, the number of the trailing edge split transverse ribs 4 is related to the width of the pressure surface 2 and the suction surface 1, and is usually 3 to 8, preferably 4 to 6, for example 4; at this time, multiple trailing edge split transverse ribs 4 are equidistantly and parallelly distributed between the suction surface 1 and the pressure surface 2 along the flow direction of the airflow.

[0043] In the present invention, the honeycomb cross ribs 3 are distributed between the suction surface 1 and the pressure surface 2 , with the upper end of the honeycomb cross ribs 3 being closely connected to the pressure surface 2 and the lower end being closely connected to the suction surface 1 .

[0044] In the present invention, the honeycomb cross ribs 3 are in the shape of a common-edge honeycomb, which is a polygon, preferably any one of a rhombus, a hexagon, an octagon, a decagon, and a dodecagon, and more preferably a hexagon. The hexagon is similar to a honeycomb, which has high structural stability; and each angle β is 120°, which enables the force to be evenly distributed, thereby providing balanced strength and stability throughout the structure; in addition, the hexagonal arrangement is seamlessly and tightly filled between the suction surface 1 and the pressure surface 2, without gaps or overlaps, thereby improving space utilization.

[0045] In the present invention, taking the hexagon as an example, the honeycomb cross ribs 3 share adjacent edges, that is, adjacent hexagons share adjacent edges, so as to maximize the heat exchange efficiency in a limited space.

[0046] In the present invention, taking a hexagon as an example, the inner side length a is 1~2D, for example, 1.1D; the rib width b is 0.25~0.5D, for example, 0.25D. If the rib width b is too small, the heat exchange area is small and the cooling efficiency is low. As the rib width increases, the structural strength increases, the average heat transfer coefficient increases, and the cooling efficiency increases; but if the rib width b is too large, the flow resistance is too large, the momentum of the cold air at the trailing edge outlet is reduced, and the cold air at the outlet cannot fit the surface, and the cooling efficiency will drop sharply.

[0047] In the present invention, the honeycomb cross ribs 3 have at least two layers, and the two-layer structure is lighter and less difficult to process. The upper and lower layers of honeycomb cross ribs 3 are staggered and aligned, and one honeycomb cross rib 3 is recorded as a unit honeycomb rib 9, that is, the center point of the upper unit honeycomb rib 9 coincides with the central axis of the rib intersection of the lower adjacent unit honeycomb rib 9, or the center point of the lower unit honeycomb rib 9 coincides with the central axis of the rib intersection of the upper adjacent unit honeycomb rib 9. The inventors have found that this arrangement can effectively reduce the temperature of the suction surface 1 of the trailing edge of the turbine blade, increase the heat transfer coefficient on both sides of the trailing edge, and effectively improve the cooling efficiency of the trailing edge.

[0048] Furthermore, the upper and lower layers of honeycomb cross ribs 3 are closely connected; the uppermost layer of honeycomb cross ribs 3 is closely connected to the inner wall of the pressure surface 2 , and the lowermost layer of honeycomb cross ribs 3 is closely connected to the inner wall of the suction surface 1 .

[0049] In one embodiment, the honeycomb cross ribs 3 are two layers, i.e., they include upper ribs 7 and lower ribs 8, and the honeycomb cross ribs 3 of the upper ribs 7 and the honeycomb cross ribs 3 of the lower ribs 8 are staggered and aligned, and one honeycomb cross rib 3 is referred to as a unit honeycomb rib 9, i.e., the center point of the unit honeycomb rib 9 of the upper rib 7 coincides with the central axis of the rib intersection of the adjacent unit honeycomb rib 9 of the lower rib 8, or the center point of the unit honeycomb rib 8 of the lower rib 8 coincides with the central axis of the rib intersection of the adjacent unit honeycomb rib 9 of the upper rib 7. At this time, the upper ribs 7 and the lower ribs 8 are closely connected; the honeycomb cross ribs 3 of the upper ribs 7 are closely connected to the inner wall of the pressure surface 2, and the honeycomb cross ribs 3 of the lower ribs 8 are closely connected to the inner wall of the suction surface 1.

[0050] In the present invention, the height Y of the honeycomb cross ribs 3 sandwiched between the suction surface 1 and the pressure surface 2 is 1-3D, for example, 1.5D. If the cooling height Y is too small, the heat exchange area becomes smaller and the cooling efficiency is reduced; if the cooling height Y is too large, the trailing edge cavity is too large, the structure is weak, and it is difficult to bear large thermal stress.

[0051] In the present invention, the distance between the honeycomb cross rib 3 and the trailing edge split cross rib 4 is 1-3D, for example, 1.25D. If the rib front S1 is too small, it cannot guide the cooling gas; if the rib front S1 is too long, it will not significantly improve the cooling efficiency.

[0052] Furthermore, the length S2 of the connection area of ​​the honeycomb cross ribs 3 along the airflow direction is determined by the honeycomb cross ribs 3, and is usually the length of 3 to 5 honeycomb cross ribs 3, for example, the length of 3 honeycomb cross ribs 3. This ensures that the cold air flows through the intersecting honeycomb ribs for sufficient heat exchange; if the length is too long, that is, the number of honeycomb cross ribs 3 is too large, the flow resistance becomes large, and the cooling efficiency at the outlet is reduced.

[0053] Furthermore, the length S3 of the slit channel from the other end of the honeycomb cross rib 3 to the end of the pressure surface 2 is 4-8D, for example, 6D. If the length S3 of the slit channel is too short, the flow guidance effect is not obvious, and if it is too long, the trailing edge volume is occupied, and the comprehensive cooling efficiency is low.

[0054] In the present invention, the honeycomb cross ribs 3 arranged between two adjacent trailing edge split transverse ribs 4 are recorded as one rib layer; a single rib layer is distributed with 3 to 8 rows of honeycomb cross ribs 3 along the airflow direction, for example, 4 rows of honeycomb cross ribs 3 are distributed; in order to increase the distribution density of the honeycomb cross ribs 3, the honeycomb cross ribs 3 distributed adjacent to the trailing edge split transverse ribs 4 are half of the honeycomb cross ribs 3 distributed along the center line, and at this time, the honeycomb cross ribs 3 distributed adjacent to two trailing edge split transverse ribs 4 in a single rib layer are actually one honeycomb cross rib 3.

[0055] Furthermore, 3 to 5 rows of honeycomb cross ribs 3 are distributed perpendicular to the airflow direction, for example, 3 rows of honeycomb cross ribs 3 are distributed.

[0056] In fact, the number of the honeycomb cross ribs 3 distributed along the airflow direction or perpendicular to the airflow direction can be adjusted according to actual conditions without strict restrictions.

[0057] In one embodiment, taking the hexagonal honeycomb cross rib 3 as an example, Figure 2As shown in FIG4 (a), a single rib layer has 4 rows of honeycomb cross ribs 3 distributed along the airflow direction, among which the honeycomb cross ribs 3 distributed next to the trailing edge split cross ribs 4 are half of the honeycomb cross ribs distributed along the center line. At this time, the honeycomb cross ribs 3 distributed next to two trailing edge split cross ribs 4 in a single rib layer are actually one honeycomb cross rib 3; 3 rows of honeycomb cross ribs 3 are distributed perpendicular to the airflow direction. Since the honeycomb cross ribs 3 share adjacent edges, the leftmost and rightmost ends of a row of honeycomb cross ribs 3 next to half a hexagon are both half hexagons distributed along the center line (as shown in the second and fourth rows in FIG4 (a)). At this time, the cold air C0 flows into the split cavity 5, and the entrance is the half ribs symmetrically divided along the center line and the rib edge of the honeycomb cross rib 3.

[0058] In the present invention, the cold air C0 flows into the split cavity 5, flows along the gaps between the suction surface 1, the pressure surface 2 and the honeycomb cross ribs 3, and is ejected from the trailing edge split outlet surface 6, forming an air film at the trailing edge of the trailing edge split outlet to reduce the heat load of the trailing edge; the flow direction of the cooling gas is guided by the trailing edge split transverse ribs 4, further improving the cooling efficiency. The suction surface 1, the pressure surface 2 and the trailing edge split transverse ribs 4 together form a fixed structure to guide the flow direction of the cooling gas; it cooperates with the honeycomb cross ribs 3 to ensure that the cooling gas can fully exchange heat in the complex honeycomb cross rib 3 structure. In particular, the structure of the honeycomb cross ribs 3, when the cold air impacts the honeycomb cross ribs 3, is dispersed into the first cold air C1, the second cold air C2, and the third cold air C3, and rushes into the upper honeycomb cross ribs 3 or the lower honeycomb cross ribs 3 from all directions, and the velocity changes in the three directions of the airflow direction, perpendicular to the airflow direction and longitudinal direction are large, which increases the turbulence of the fluid and has a large overall heat transfer coefficient.

[0059] For ease of understanding, the simplified airflow diagram of the trailing edge split cooling structure shown in Figure 1 (b) is combined with Figure 2 A rib layer airflow direction diagram is shown, from which it can be seen that: the cold air C0 is guided by the trailing edge split cross rib 4, flows from the upper rib 7 (or the lower rib 8) into the honeycomb cross rib 3, and when impacting the honeycomb cross rib 3, the cold air C0 is dispersed into the first cold air C1, the second cold air C2, and the third cold air C3, and rushes into the ribs between the lower rib 8 (or the upper rib 7) from all directions, so that it can fully exchange heat with the pressure surface 2, thereby improving the cooling efficiency of the pressure surface 2; the cooling air C4 after sufficient heat exchange passes through the split cavity 5, and is ejected from the trailing edge split outlet surface 6, and is mixed with the high-temperature combustion gas G0 on the outer surface to form M0, which covers the surface of the trailing edge rear end, thereby forming low-temperature protection for the trailing edge rear end.

[0060] On the other hand, according to the present invention, there is provided a trailing edge split cooling method applicable to a turbine blade, wherein cooling is performed using the cooling structure described in the first aspect.

[0061] During cooling, cold air C0 flows into the split cavity 5, flows along the gaps between the suction surface 1, the pressure surface 2 and the honeycomb cross ribs 3, and is ejected from the trailing edge split outlet surface 6, forming an air film at the trailing edge of the trailing edge split outlet to reduce the trailing edge heat load.

[0062] In yet another aspect, a turbine blade trailing edge slot cooling device is provided according to the present invention, the device comprising the cooling structure described in the first aspect.

[0063] The present invention is further described below through specific examples, but these examples are merely exemplary and do not constitute any limitation to the scope of protection of the present invention.

[0064] Example 1

[0065] As shown in Figures 1 (a) to 4 (b), the suction surface 1 and the pressure surface 2 are opposite to each other, and a slit cavity 5 is formed therebetween. A honeycomb cross rib 3 is arranged in the slit cavity 5, and the honeycomb cross ribs 3 are separated by the trailing edge slit transverse rib 4. The right inner wall edge of the pressure surface 2 along the cooling gas flow direction is set as a fillet, the lip thickness D of the pressure surface 2 is 4mm, and the length S4 of the trailing edge slit outlet on the right side of the pressure surface 2 is 5.85D; the thickness of the trailing edge slit outlet surface 6 is D, and the front view of the suction surface 1 excluding the trailing edge slit outlet surface 6 is trapezoidal, and the trailing edge slit outlet surface 6 forms an outlet angle α with the tangent direction of the trailing edge, and the outlet angle α is 20°, and the edge of the trailing edge slit outlet surface 6 is set as a fillet; the thickness H of the trailing edge slit transverse rib 4 is 0.5D, the distance P between the trailing edge slit transverse ribs 4 is 6.5D, and the distance S5 between the trailing edge slit transverse rib 4 and the left end of the suction surface 1 is 2.5D; The ribs 3 are hexagonal, and the honeycomb cross ribs 3 share adjacent edges. The inner side length a is 1.1D, the rib width b is 0.25D, the adjacent rib side angle β is 120°, and the honeycomb cross ribs 3 are two layers, namely the upper ribs 7 and the lower ribs 8 as shown in the figure. The honeycomb cross ribs 3 of the upper ribs 7 and the honeycomb cross ribs 3 of the lower ribs 8 are staggered and aligned, the height Y of the honeycomb cross ribs 3 clamped between the suction surface 1 and the pressure surface 2 is 1.5D, the rib front S1 is 1.25D, the connection area length S2 is 6.5D, the channel length S3 in the split seam is 6D, and a single rib layer is provided with 4 rows of honeycomb cross ribs 3 along the airflow direction, and 3 rows of honeycomb cross ribs 3 perpendicular to the airflow direction.

[0066] Comparative Example 1 FIG5 (a) shows a top view of the trailing edge slit cooling structure in the comparative example, and FIG5 (b) shows a schematic diagram of the structure of a single rib layer in the trailing edge slit cooling structure composed of a comparative suction surface 10, a comparative pressure surface 11, a comparative cylinder 12, a comparative slit cavity 13 and a comparative slit outlet surface 14. The trailing edge slit cooling structure has a total of 3 single rib layers. The lip thickness of the comparative suction surface 10 and the comparative pressure surface 11 is uniform D, D=4mm; the comparative cylinder 12 is distributed with 6 rows of staggered circular spoiler columns along the airflow direction, from left to right, the first row, the third row and the fifth row are respectively distributed with 4 circular spoiler columns, and the second row, the fourth row and the sixth row are respectively distributed with 5 circular spoiler columns. The horizontal distance between the comparative cylinders 12 is 1.5D, perpendicular to the airflow direction, the spacing of the comparative cylinders 12 is 2D, and the diameter is D; the cavity height H is 1.5D. The outlet angle α is 20°; the position of the cooling structure inside the spoiler column is the same as the position of the honeycomb cross rib 3 in Example 1, S6 in front of the cylindrical group is 3.75D; the length of the connection area S2 is 6.5D; the length of the channel inside the slit S3 is 6D; the length of the slit outlet surface S4 is 5.85D.

[0067] The cooling structure in Example 1 and the cooling structure in Comparative Example 1 were respectively heated to 0.001 kg / m 3 The air flow rate was numerically simulated in FLUENT. FIG6 (a) shows the cooling efficiency distribution diagram of the trailing edge slit cooling structure in comparative example 1; FIG6 (b) shows the cooling efficiency distribution diagram of the cooling structure in embodiment 1. It can be seen that the outer wall cooling efficiency in embodiment 1 is higher than that in comparative example 1.

[0068] The average heat transfer coefficient of Example 1 is 62.1 W / (m 2 ∙K), the average heat transfer coefficient of comparative example 1 is 45.6W / (m 2 ∙K), the average heat transfer coefficient increased by 36.2% compared with the control example 1; Figure 7 A comparison of the cooling efficiencies of Example 1 and Comparative Example 1 is shown, and it can be seen that the maximum value of the centerline comprehensive cooling efficiency of the air film hole 5 of Example 1 reaches 80.8%, and the average value is 75.6%. The average value of the centerline comprehensive cooling efficiency of the air film hole 5 of Comparative Example 1 is 70.2%, and the centerline comprehensive cooling efficiency of the air film hole 5 of Example 1 is increased by 5.4%.

[0069] The present invention is described in detail above in combination with preferred embodiments and exemplary examples. However, it should be noted that these specific embodiments are only illustrative explanations of the present invention and do not constitute any limitation on the protection scope of the present invention. Without exceeding the spirit and protection scope of the present invention, various improvements, equivalent substitutions or modifications may be made to the technical content of the present invention and its embodiments, which all fall within the protection scope of the present invention. The protection scope of the present invention shall be subject to the attached claims.

Claims

1. A trailing edge split cooling structure, characterized in that: The structure comprises: a suction surface (1), a pressure surface (2), a split cavity (5) and honeycomb cross ribs (3); the suction surface (1) and the pressure surface (2) are positioned opposite to each other, forming a split cavity (5) therebetween, and the honeycomb cross ribs (3) are arranged in the split cavity (5).

2. The cooling structure according to claim 1, characterized in that: Preferably, the slit cavity (5) is used to accommodate cooling gas and guide its flow.

3. The cooling structure according to claim 1, characterized in that: The honeycomb cross ribs (3) are used to increase the turbulence of the cooling gas, thereby promoting heat transfer.

4. The cooling structure according to claim 1, characterized in that: A portion of the pressure surface (2) is removed to form a trailing edge half-split structure.

5. The cooling structure according to claim 4, characterized in that: On the suction surface (1), a trailing edge split outlet surface (6) is provided at a position corresponding to the trailing edge half split structure of the pressure surface (2).

6. The cooling structure according to claim 4, characterized in that: The trailing edge split outlet surface (6) is used to guide the cooling gas to spray out and form a cooling gas film.

7. The cooling structure according to claim 4, characterized in that: The edge of the trailing edge split exit surface (6) is chamfered or rounded.

8. The cooling structure according to claim 1, characterized in that: The honeycomb cross ribs (3) are separated by trailing edge split transverse ribs (4), and the trailing edge split transverse ribs (4) are used to guide the flow direction of the cooling gas.

9. A method for cooling the trailing edge of a turbine blade, characterized in that: The cooling structure described in any one of claims 1 to 8 is used for trailing edge split cooling.

10. A turbine blade trailing edge split cooling device, characterized in that: The device comprises the cooling structure according to any one of claims 1 to 8.

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