Turbine rotor blade with combined slot bottom discrete slot inclined air injection structure and winglet structure

Abstract

The application discloses a turbine rotor blade with combined slot bottom discrete slot inclined air injection structure and winglet structure, which comprises a blade body, a pressure side shoulder wall is arranged at the upper end of the pressure side of the blade body, a pressure side shoulder wall section is arranged at the inner side of the pressure side shoulder wall, a suction side shoulder wall is arranged at the upper end of the suction side of the blade body, and a suction side winglet is arranged at the inner side of the suction side shoulder wall; a slot bottom is arranged between the pressure side shoulder wall and the suction side shoulder wall, and the pressure side shoulder wall, the suction side shoulder wall and the slot bottom form a concave groove blade tip of the blade body; a discrete slot is arranged at the slot bottom near the pressure side in an acute angle, and a cold gas inlet of the discrete slot is communicated with a cold gas outlet of a blade inner cold cavity. The discrete film holes at the top and bottom of the concave groove are optimally designed as the discrete slots for low-angle inclined injection of cold air to the pressure side shoulder wall, the inner wall surface of the pressure side shoulder wall and the inner wall surface of the suction side shoulder wall are respectively subjected to section modification and winglet structure process treatment, and the blade top structure with high leakage suppression and low heat load is obtained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aero-engines, and particularly relates to a turbine moving blade suitable for an aero-engine. BACKGROUND

[0002] As an important component of an aero-engine, the turbine moving blade is closely related to the working efficiency of the turbine. In order to ensure the safe operation of the aero-turbine, a certain radial gap is required between the moving blade tip and the static casing. The high-temperature gas from the combustion chamber flows through the radial gap to form a leakage flow. The tip gap leakage increases the flow loss at the gap, resulting in a decrease in the aerodynamic performance of the turbine. On the other hand, the high-temperature gas washes the tip, the tip thermal load increases, and the local overheating phenomenon is prominent, causing the tip to be oxidized and ablated, thereby reducing the safety and reliability of the turbine.

[0003] In view of the large tip gap leakage and tip ablation phenomenon, existing research has improved the shoulder wall modeling and the structure and layout of the film hole. For example, patents CN204552835U and CN217176719U, and the similar patent CN112240228A use an intermittent slot hole to improve the tip cooling effect and the aerodynamic performance after optimizing the rib structure at the blade tip and the layout of the film hole. Patent CN115169032A proposes a turbine blade design method with a tip groove and a winglet composite structure, and patent CN105179022B designs a turbine blade with a rib wing structure at the blade tip, which aims to reduce the tip gap leakage, improve the heat exchange performance of the blade tip, and prolong the working life of the turbine. Although the above-mentioned patents are beneficial to improving the tip gas and heat performance, the tip thermal load is still large and prone to ablation when the turbine inlet temperature exceeds 2000K, which is a difficult problem that needs to be solved for the turbine moving blade. Therefore, it is important to develop a high-efficiency cooling tip structure with high leakage suppression and low blade tip heat exchange.

[0004] The present application takes the GE-E3 high-pressure turbine first-stage moving blade as a prototype, optimizes the discrete film holes at the groove bottom into discrete slits with an inclination angle under the same cold gas outflow area and mass flow, changes the cold gas outflow angle from perpendicular 90° to 20° to the pressure side, and makes an inclined surface cut on the inner wall edge of the pressure side shoulder wall from the leading edge to the trailing edge to the outside of the shoulder wall, and extends the inner wall edge of the suction side shoulder wall from the leading edge to the trailing edge to the inside of the shoulder wall to form a winglet structure. The optimized cooling structure at the blade tip can significantly reduce the tip gap leakage and the thermal load at the blade tip, and improve the gas and heat performance and the working reliability of the turbine. SUMMARY

[0005] The present application aims to provide a turbine moving blade combining a slot bottom discrete slot inclined air injection structure and a winglet structure to solve the problem of large tip heat load and easy ablation of existing turbine moving blades.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A turbine moving blade combining a slot bottom discrete slot inclined air injection structure and a winglet structure, comprising a blade body, one side of the blade body being a pressure side and the other side being a suction side, the blade body being provided with a blade internal cooling cavity, and the blade internal cooling cavity being provided with a cold air outlet; an upper end of the pressure side of the blade body is provided with a pressure side shoulder wall, an inner side of the pressure side shoulder wall is provided with a pressure side shoulder wall section, an upper end of the suction side of the blade body is provided with a suction side shoulder wall, and an inner side of the suction side shoulder wall is provided with a suction side winglet; a slot bottom is arranged between the pressure side shoulder wall and the suction side shoulder wall, and the pressure side shoulder wall, the suction side shoulder wall and the slot bottom form a concave slot tip of the blade body; a discrete slot is obliquely arranged on the slot bottom close to the pressure side, and a cold air inlet of the discrete slot is in communication with the cold air outlet of the blade internal cooling cavity.

[0008] The height S of the blade body is 41.0 mm, the chord length C x is 38.2 mm, and the axial chord length C ax is 28.7 mm.

[0009] The height h of the pressure side shoulder wall and the suction side shoulder wall is 1.0% to 5.0% of the height S of the blade body, and the value range is 0.41 to 2.05 mm; the width w of the pressure side shoulder wall and the suction side shoulder wall is 1.0% to 2.0% of the height S of the blade body, and the value range is 0.41 to 0.82 mm.

[0010] The inner wall surface of the pressure side shoulder wall is smoothly cut off from the leading edge to the trailing edge at an inclination angle a of 80° to 85° to form the pressure side shoulder wall section.

[0011] The suction side winglet is located on the inner side of the suction side shoulder wall, the height m is 1 / 2 of the height h of the shoulder wall, the width n is 1.0% to 2.0% of the height S of the blade body, and the value range is 0.41 to 0.82 mm, and the suction side winglet is obtained by linearly scanning from the leading edge to the trailing edge of the suction side shoulder wall.

[0012] The distance δ of the discrete slot to the inner wall edge of the pressure side shoulder wall is 1.0% to 3.0% of the height S of the blade body, and the value range is 0.41 to 1.23 mm; and the distance l of the starting point of the discrete slot to the starting point of the leading edge of the blade body is 5.0% of the axial chord length C ax of the blade body, and the value is 1.435 mm.

[0013] The number of segments of the discrete slot is 3, 4 or 5, if 3, the length p of each discrete slot is 6.20 mm, if 4, the length p of each discrete slot is 4.65 mm, if 5, the length p of each discrete slot is 3.72 mm, the interval between adjacent discrete slots is 1.0 mm; the width d of the discrete slot is in the range of 0.1-0.3 mm, the outflow angle of the cold gas, that is, the angle β between the discrete slot and the groove bottom is in the range of 10-20°, and the depth f of the discrete slot along the outflow direction of the cold gas is in the range of 2.0-3.0 mm.

[0014] The depth g of the discrete slot in the vertical direction of the blade inner cooling cavity is in the range of 2.0-5.0 mm.

[0015] The pressure side shoulder wall section and the discrete slot are cut and processed by laser cutting technology.

[0016] The suction side winglet and the suction side shoulder wall are integrally cast and processed.

[0017] The principle of the present application is that: the present application arranges a discrete slot on the pressure side of the groove bottom of the groove tip, the cold gas is inclined to flow out of the slot and hit the inner wall surface of the pressure side shoulder wall, the pressure side corner vortex in the groove is lifted, and part of the cold gas is rolled into the pressure side corner vortex to increase the vortex size, and the pressure side corner vortex develops to the casing to reduce the effective flow area of the leakage flow. The cold gas not rolled into the pressure side corner vortex flows up along the wall to the casing, hinders the high-temperature gas from entering the tip clearance and produces the effect of flowing out of the pressure side shoulder wall in the opposite direction, and the inclined section obtained by modifying the inner wall edge of the pressure side shoulder wall promotes the flow of the cold gas to the pressure side shoulder wall, enhances the cold gas coverage effect, and further hinders the inflow of the high-temperature gas on the pressure side shoulder wall. The suction side shoulder wall inner side winglet increases the flow resistance of the leakage flow, the leakage flow forms flow separation on the surface of the suction side shoulder wall, suppresses the tip clearance leakage, and reduces the heat transfer coefficient and thermal load of the tip. Compared with the groove tip, the combination of the groove bottom discrete slot inclined jet structure and the suction side shoulder wall inner side winglet structure can effectively cool the tip, suppress the tip clearance leakage and solve the tip ablation problem.

[0018] Advantages: Compared with the prior art, the present application has the following advantages:

[0019] 1. The groove bottom film hole of the present application is designed as a discrete slot, it is found that under the same cold gas flow, the cold gas jetted at a low angle by the discrete slot hinders the high-temperature gas from entering the tip clearance, the tip clearance leakage is reduced by nearly 12.5%, and the total pressure loss is reduced by nearly 5.0%.

[0020] 2、The present application has the effect of efficiently inhibiting tip clearance leakage, the distribution area of the high heat exchange coefficient of the blade top is reduced, the average heat exchange coefficient of the blade top is reduced by 10.17% to 16.46%, the average heat exchange coefficient of the shoulder wall surface is reduced by 29.38%, the heat exchange of the shoulder wall is weakened, and the problem of blade tip ablation is effectively solved.

[0021] 3、The cold air sprayed by the discrete slot in the present application can hinder the high-temperature gas from entering the tip clearance while producing the effect of flowing out of the pressure side shoulder wall in the opposite direction; the suction side wing can increase the flow resistance of the clearance leakage, the flow separation of the suction side shoulder wall surface, the effect of weakening the heat exchange of the suction side shoulder wall and inhibiting the clearance leakage, the improvement of the aerothermal performance of the moving blade, and the guarantee of safety and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a schematic diagram of the model structure of the present application;

[0023] Figure 2 It is a schematic diagram of the model cross section of the present application;

[0024] Figure 3 It is a schematic diagram of the axial cross-sectional streamline distribution of the embodiment of the present application;

[0025] Figure 4 It is a distribution diagram of the heat exchange coefficient of the blade top and the heat exchange coefficient of the groove of the embodiment of the present application;

[0026] In the figure: 1 is a blade body, 2 is a pressure side shoulder wall, 3 is a suction side shoulder wall, 4 is a pressure side shoulder wall section, 5 is a suction side wing, 6 is a groove bottom, 7 is a discrete slot, and 8 is a blade internal cooling cavity. DETAILED DESCRIPTION

[0027] The present application will be further explained in combination with the drawings.

[0028] As shown in Figure 1 and Figure 2 , a turbine moving blade with a combined groove bottom discrete slot inclined air injection structure and wing structure of the present application comprises a blade body 1, one side of the blade body 1 is a pressure side, and the other side is a suction side, a blade internal cooling cavity 8 is arranged in the blade body 1, and the blade internal cooling cavity 8 is provided with a cold air outlet; a pressure side shoulder wall 2 is arranged at the upper end of the pressure side of the blade body 1, a pressure side shoulder wall section 4 is arranged on the inner side of the pressure side shoulder wall 2, a suction side shoulder wall 3 is arranged at the upper end of the suction side of the blade body 1, and a suction side wing 5 is arranged on the inner side of the suction side shoulder wall 3; a groove bottom 6 is arranged between the pressure side shoulder wall 2 and the suction side shoulder wall 3, and the pressure side shoulder wall 2, the suction side shoulder wall 3 and the groove bottom 6 form a groove tip of the blade body 1; a discrete slot 7 is arranged on the groove bottom 6 near the pressure side at an acute angle, and the cold air inlet of the discrete slot 7 is in communication with the cold air outlet of the blade internal cooling cavity 8.

[0029] The height S of the vane body 1 is 41.0 mm, and the chord length C x The axial chord length C ax The axial chord length C

[0030] The height h of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is 1.0% to 5.0% of the height S of the vane body 1, and the value range is 0.41 to 2.05 mm; the width w of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is 1.0% to 2.0% of the height S of the vane body 1, and the value range is 0.41 to 0.82 mm.

[0031] The inner wall surface of the pressure side shoulder wall 2 is smoothly cut off from the leading edge to the trailing edge at an inclination angle a of 80° to 85° to form a pressure side shoulder wall section 4.

[0032] The suction side winglet 5 is located inside the suction side shoulder wall 3, the height m is 1 / 2 of the shoulder wall height h, the width n is 1.0% to 2.0% of the height S of the vane body 1, and the value range is 0.41 to 0.82 mm; the suction side winglet 5 is obtained by linearly scanning from the leading edge to the trailing edge of the suction side shoulder wall 3.

[0033] The distance δ of the discrete slot 7 to the inner wall edge of the pressure side shoulder wall 2 is 1.0% to 3.0% of the height S of the vane body 1, and the value range is 0.41 to 1.23 mm; the distance l from the starting point of the discrete slot 7 to the starting point of the leading edge of the vane body 1 is 5.0% of the axial chord length C ax of the vane body 1, and the value is 1.435 mm. The number of sections of the discrete slot 7 is 3, 4 or 5; if it is 3, the length p of each section of the discrete slot 7 is 6.20 mm; if it is 4, the length p of each section of the discrete slot 5 is 4.65 mm; if it is 5, the length p of each section of the discrete slot 5 is 3.72 mm, and the interval between adjacent discrete slots 7 is 1.0 mm; the width d of the discrete slot 7 is 0.1 to 0.3 mm, the cold air outflow angle, that is, the angle β between the discrete slot 7 and the groove bottom 6 is 10° to 20°, and the depth f of the discrete slot 7 in the direction of the cold air outflow is 2.0 to 3.0 mm. The depth g of the discrete slot 7 in the vertical direction of the vane inner cooling cavity 8 is 2.0 to 5.0 mm.

[0034] The pressure side shoulder wall section 4 and the discrete slot 7 are cut and processed by laser cutting technology, and the communication form with the meandering inner cooling structure is designed according to the actual situation.

[0035] The suction side winglet 5 and the suction side shoulder wall 3 are integrally cast and processed.

[0036] Figure 3 is a schematic diagram of the axial cross-sectional flow line distribution of the embodiment of the application, Figure 4The figure is a heat exchange coefficient distribution diagram of the blade tip and the groove of the embodiment of the present application. The discrete film holes at the bottom of the groove of the blade tip are designed as discrete slits for spraying cold air at a low angle to the pressure side shoulder wall, and the inner wall surface of the pressure side shoulder wall and the inner wall surface of the suction side shoulder wall are respectively processed by cutting and shaping and winglet structure, so that the blade tip structure with high leakage suppression and low heat load is obtained. Compared with the original blade tip, the blade tip gap leakage of the present application is reduced by nearly 12.5%, the total pressure loss is reduced to nearly 5.0%, and the blade tip aerodynamic performance is improved; the high heat exchange coefficient distribution area of the blade tip is reduced, the average heat exchange coefficient of the blade tip is reduced by 10.17% to 16.46%, and the average heat exchange coefficient of the shoulder wall surface is reduced by 29.38%, the shoulder wall heat exchange is weakened, and the blade tip ablation problem is effectively solved.

[0037] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled persons in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A turbine blade combining a discrete slit-bottom inclined jet structure and a small airfoil structure, characterized in that: The blade body (1) has a pressure side on one side and a suction side on the other side. An internal cooling cavity (8) is provided inside the blade body (1), and a cold air outlet is provided in the internal cooling cavity (8). A pressure side shoulder wall (2) is provided at the upper end of the pressure side of the blade body (1), and a pressure side shoulder wall cross-section (4) is provided inside the pressure side shoulder wall (2). A suction side shoulder wall (3) is provided at the upper end of the suction side of the blade body (1), and a suction side wing (5) is provided inside the suction side shoulder wall (3). A groove bottom (6) is provided between the pressure side shoulder wall (2) and the suction side shoulder wall (3). The pressure side shoulder wall (2), the suction side shoulder wall (3), and the groove bottom (6) form the groove tip of the blade body (1). A discrete slit (7) is opened at an acute angle near the pressure side of the groove bottom (6). The cold air inlet of the discrete slit (7) is connected to the cold air outlet of the internal cooling cavity (8) of the blade. The height of the blade body (1) S The chord length is 41.0 mm. C x It is 38.2 mm, and the axial chord length is... C ax It is 28.7mm; The height of the pressure-side shoulder wall (2) and the suction-side shoulder wall (3) h The blade body height is 1.0%~5.0% (1). S The value ranges from 0.41 to 2.05 mm; the width of the pressure-side shoulder wall (2) and the suction-side shoulder wall (3) w The height of the blade body (1) is 1.0% to 2.0%. S The value ranges from 0.41 to 0.82 mm. The inner wall surface of the pressure shoulder wall (2) is inclined at an angle of 80°~85°. a A smooth excision is made from the anterior edge to the posterior edge to form a pressure side shoulder wall section (4); The suction-side wing (5) is located inside the suction-side shoulder wall (3), at a height of m Shoulder height h 1 / 2, width n The blade body (1) height is 1.0%~2.0%. S The value range is 0.41~0.82mm. The suction side winglet (5) is obtained by linear sweeping from the leading edge of the suction side shoulder wall (3) to the trailing edge. The distance from the discrete slit (7) to the inner edge of the pressure-side shoulder wall (2) δ The blade body height is 1.0% to 3.0% (1). S The value ranges from 0.41 to 1.23 mm, and the distance from the starting point of the discrete slit (7) to the starting point of the leading edge of the blade body (1) is... l The axial chord length of the blade body (1) is 5.0%. C ax The value is 1.435mm; The discrete slit (7) has 3, 4, or 5 segments. If it has 3 segments, the length of each discrete slit (7) is... p The value is 6.20 mm. If there are 4 segments, the length of each discrete slit (7) is... p The value is 4.65 mm. If there are 5 segments, the length of each discrete slit (7) is... p The value is 3.72 mm, and the interval between adjacent discrete slits (7) is 1.0 mm; the width of the discrete slits (7) is... d The value range is 0.1~0.3mm, and the cold air outflow angle is the angle between the discrete slit (7) and the bottom of the trough (6). β The value range is 10°~20°, and the depth of the discrete slit (7) along the direction of cold air outflow is... f The value range is 2.0~3.0mm; The depth of the discrete slit (7) perpendicular to the blade internal cooling cavity (8) g The value range is 2.0~5.0mm.

2. The turbine blade of the combined slot bottom discrete slit inclined jet structure and winglet structure according to claim 1, characterized in that: The pressure side shoulder wall section (4) and discrete slits (7) are obtained by laser cutting technology.

3. The turbine blade of the combined slot bottom discrete slit inclined jet structure and winglet structure according to claim 1, characterized in that: The suction side wing (5) and suction side shoulder wall (3) are integrally cast and machined.

Images