CN110566284A - Groove blade top structure with partition ribs - Google Patents

Abstract

The invention discloses a grooved blade top structure with barrier ribs. By arranging upstream barrier ribs and downstream barrier ribs on the blade top, and respectively arranging leading edge dust removal holes on the middle arc near the leading edge, two The inter-rib dust removal holes are arranged in the middle of the barrier ribs, and the rib downstream dust removal holes are arranged downstream of the barrier ribs. Adding barrier ribs on the top of the grooved blade can reduce the flow loss caused by the gap leakage flow and effectively improve the efficiency of the turbine blade, and the two barrier ribs can reduce the high heat exchange area near the leading edge of the grooved blade. Arranging dust removal holes on the middle arc near the leading edge can form effective air film coverage on the leading edge of the blade tip, avoid thermal corrosion of the blade caused by the high heat exchange area at the leading edge of the blade tip, and prolong the service life of the blade. The dust removal holes are set behind the barrier ribs, which can form an effective air film protection behind the ribs, improve the heat transfer performance of the top of the blade, and improve the working efficiency of the turbine blade. The grooved blade top structure has the characteristics of simple processing and low cost.

Description

A grooved blade top structure with barrier ribs

technical field

The invention relates to the technical field of cooling of gas turbine blades, in particular to a grooved blade top structure with barrier ribs for the turbine blade.

technical background

The gap leakage flow will scour the top of the high-pressure turbine power blade at high speed, making the turbine blade tip area one of the areas with the highest heat transfer coefficient in the aero-engine. The height of the blade tip clearance is very small, so there is a significant difference between the flow field structure inside the blade tip clearance and the high-temperature gas in the channel. Relatively speaking, the flow state of the clearance flow is more complicated. In order to effectively reduce the heat load in the tip area and protect the tip from high-temperature gas corrosion, domestic and foreign scholars have done a lot of experiments and numerical simulation calculations for different tip shapes, and studied the flow and heat transfer mechanism of the tip.

The shape of the blade top structure will have a great impact on the heat transfer of the blade top. In 1989, Metzger et al. (CavityHeat Transfer on a Transverse Grooved Wall in a Narrow Flow Channel. Journal of Heat Transfer, 1989, 111(1): 73-79 .) The heat transfer coefficient of a narrow channel with rectangular grooves was measured experimentally, and the leakage was found to decrease with the increase of the aspect ratio of the grooves. In 1999, Bunker et al. (Heat Transfer and Flow on the First-Stage Blade Tip of a Power Generation Gas Turbine: Part1-Experimental Results. Journal of Turbomachinery, 1999, 122 (2): 263-271.) given a representative Turbine operating conditions, a detailed heat transfer coefficient distribution of a large gas generator turbine cascade tip was obtained. Ahn et al. (Film Cooling Effectiveness on a Gas Turbine Blade Tip and ShroundUsing Pressure Sensitive Paint. ASME Paper GT-2003-53429.) used pressure-sensitive paint testing techniques to experimentally measure the film cooling characteristics of grooved and flat-topped blade tips. Bunker [31] obtained a detailed heat transfer coefficient distribution of a large gas generator turbine cascade blade tip through experiments, given representative turbine operating conditions. In 2015, Zhang et al. (Impact of Cooling Injection on the Transonic Over-Tip Leakage Flow and Squealer Aerothermal Design Optimization. Journal of Engineering for GasTurbines and Power, 2015, 137(6): 062603-062603-7.) experimentally studied transonic The effect of the film hole distribution on the heat transfer at the top of the blade under certain conditions.

A reasonable blade tip structure can not only effectively reduce the flow loss caused by the gap leakage flow, but also effectively protect the blade tip from being corroded by high-temperature gas, prolong the service life of the blade, and improve the working efficiency of the turbine blade.

Contents of the invention

In order to avoid the deficiencies in the prior art, the present invention proposes a grooved blade tip structure with barrier ribs; the grooved blade tip structure can effectively reduce the flow loss caused by the gap leakage flow, and improve the chord and tail of the blade tip. The air film coverage area of the edge area prolongs the service life of the blade and effectively improves the working efficiency of the turbine blade.

The technical solution adopted by the present invention to solve the technical problem is: comprising turbine blades, leading edge dust removal holes, intercostal dust removal holes, rib downstream dust removal holes, upstream barrier ribs, downstream barrier ribs, groove blade tops, midchord cooling passages, The leading edge cooling channel is characterized in that an upstream barrier rib and a downstream barrier rib are respectively provided on the top of the groove blade, and front edge dust removal holes are respectively provided near the leading edge of the blade tip, and are arranged between the upstream barrier rib and the downstream barrier rib The dust removal holes between the ribs are arranged downstream of the downstream barrier ribs. The two ends of the dust removal holes form the outlet and inlet of the airflow respectively, and communicate with the blade center chord cooling channel and the leading edge cooling channel; the leading edge dust removal holes, ribs The dust removal holes between the ribs and the dust removal holes downstream of the ribs are respectively located on the middle arc of the blade tip of the groove, and the distance between the dust removal holes between the ribs and the upstream barrier rib and the downstream barrier rib is the same, and the groove depth of the groove blade tip of the turbine blade is the same as The upstream and downstream barrier ribs have the same rib height;

The groove depth H of the grooved blade top ranges from 0.7 to 1.1 mm, the groove edge width W of the grooved blade top ranges from 0.5 to 0.7 mm, and the blade axial chord length G of the grooved blade top , the value range is 32 ~ 48mm;

The front edge dust removal hole is a cylindrical hole, the front edge dust removal hole diameter i ranges from 0.8 to 1.2mm, and the distance L from the center of the front edge dust removal hole to the front edge point ranges from 3i to 5i;

The dust removal holes between the ribs and the dust removal holes downstream of the ribs are cylindrical holes, and the diameter I of the dust removal holes between the ribs and the downstream dust removal holes of the ribs ranges from 1 to 1.2 mm. The distance between the dust removal holes downstream of the ribs and the downstream barrier rib N, the value range is 2I～4I;

The angle α between the upstream barrier rib and the central axis ranges from 65° to 75°, and the distance m from the upstream barrier rib to the front edge point ranges from 7i to 10i.

The distance M between the upstream barrier rib and the downstream barrier rib ranges from 4I to 6I.

Beneficial effect

The present invention proposes a grooved blade tip structure with barrier ribs, by arranging upstream barrier ribs and downstream barrier ribs on the grooved blade tip, and respectively arranging leading edge dust removal holes in the area close to the leading edge of the blade tip, the upstream barrier Between the ribs and the downstream blocking ribs, inter-cost dust removal holes are arranged, and downstream of the downstream blocking ribs, downstream dust removal holes of the ribs are arranged. The dust removal holes on the leading edge, the dust removal holes between the ribs and the downstream dust removal holes of the ribs are located on the center arc of the blade top. The feature of this structure is that adding two barrier ribs to the groove tip can significantly reduce the flow loss caused by the gap leakage flow, effectively improving the efficiency of the turbine blade, and the two barrier ribs can reduce the area of the groove tip near the leading edge high heat exchange area. Arranging dust removal holes on the center arc near the leading edge can form effective air film coverage on the leading edge of the blade tip, avoid thermal corrosion of the blade caused by the high heat exchange area at the leading edge of the blade tip, and prolong the service life of the blade. Since the addition of barrier ribs will form a high heat exchange area behind the ribs, dust removal holes are arranged behind the barrier ribs to form an effective air film protection behind the ribs, which effectively improves the heat transfer performance of the top of the blade and prolongs the life of the blade. service life and improve the working efficiency of turbine blades. In addition, the grooved blade top structure with barrier ribs also has the characteristics of simple processing and low cost.

Description of drawings

A grooved blade tip structure with barrier ribs according to the present invention will be further described in detail below with reference to the drawings and embodiments.

Fig. 1 is the schematic diagram of the structure of the grooved blade top with barrier ribs of the present invention

Fig. 2 is a top view of the grooved blade top structure with barrier ribs of the present invention

Fig. 3 is the front view of the grooved blade top structure with barrier ribs of the present invention

Fig. 4 is a schematic diagram of the dust removal hole air supply channel of the grooved blade top structure of the present invention

in the picture

1. Turbine blade 2. Leading edge dust removal hole 3. Intercostal dust removal hole 4. Rib downstream dust removal hole 5. Upstream barrier rib 6. Downstream barrier rib 7. Groove tip 8. Mid-chord cooling channel 9. Leading edge cooling channel

A. Cold air in the middle chord channel B. Cold air in the leading edge channel C. Outflow cold air D. Outflow cold air E. Outflow cold air F. Middle arc G. Blade axial chord length H. Groove blade top Groove depth i. Aperture diameter of front edge dust removal hole I. Aperture diameter of inter-cost dust removal hole and rib downstream dust removal hole J. Rib height of barrier rib K. Central axis L. Distance from hole center of front edge dust removal hole to front edge point m .The distance from the upstream barrier rib to the leading edge point M. The distance from the upstream barrier rib to the downstream barrier rib N. The distance from the dust removal hole downstream of the rib to the downstream barrier rib O. The leading edge point W. The edge width of the blade top groove α. The angle between the upstream barrier rib and the central axis β. The angle between the downstream barrier rib and the central axis

Detailed ways

This embodiment is a grooved blade top structure with barrier ribs.

Referring to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, the grooved blade top structure with barrier ribs in this embodiment consists of turbine blade 1, leading edge dust removal hole 2, intercostal dust removal hole 3, rib downstream dust removal hole 4, upstream The barrier rib 5, the downstream barrier rib 6, the groove tip 7, the midchord cooling channel 8, and the leading edge cooling channel 9 are composed. Upstream barrier ribs 5 and downstream barrier ribs 6 are respectively provided on the grooved blade top 7, and front edge dust removal holes 2 are respectively provided near the leading edge of the blade top, and intercostal spaces are provided between the upstream barrier ribs 5 and the downstream barrier ribs 6. The dust removal hole 3 is arranged downstream of the downstream barrier rib 6. The downstream dust removal hole 4 of the rib is arranged. The dust removal holes 2 at the leading edge, the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs are respectively located on the mid-arc line of the blade tip of the groove blade 7, and the distance between the dust removal holes 3 between the ribs and the upstream barrier rib 5 and downstream barrier rib 6 Similarly, the groove depth of the groove tip of the turbine blade 1 is the same as the rib height of the upstream barrier rib 5 and the downstream barrier rib 6 .

In this embodiment, the groove depth of the groove blade top 7 is H, and the value range is 0.7-1.1 mm; the groove edge width of the groove blade top 7 is W, and the value range is 0.5-0.7 mm; The axial chord length of the blade of 7 is G, and the value range is 32-48mm. The front edge dust removal hole 2 is a cylindrical hole, the diameter i of the front edge dust removal hole 2 ranges from 0.8 to 1.2mm, and the distance L from the center of the front edge dust removal hole 2 to the front edge point ranges from 3i to 5i. The dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs are cylindrical holes, and the diameter I of the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs ranges from 1 to 1.2 mm. The distance N between the dust removal holes 4 downstream of the ribs and the downstream barrier ribs ranges from 2I to 4I. The angle between the upstream barrier rib 5 and the central axis is α, and the value range is 65-75°. The distance m between the upstream barrier rib 5 and the leading edge point is 7i-10i. The distance M between the upstream barrier rib 5 and the downstream barrier rib 6 ranges from 4I to 6I.

Embodiment one

The structure of the grooved blade tip with barrier ribs in this embodiment is that the upstream barrier rib 5 and the downstream barrier rib 6 are arranged on the grooved blade tip 7, and the leading edge dust removal holes 2 are respectively arranged in the area close to the leading edge of the blade tip, and the upstream Between the barrier rib 5 and the downstream barrier rib 6, inter-cost dust removal holes 3 are arranged, and downstream of the downstream barrier rib 6, the rib downstream dust removal holes 4 are arranged. The dust removal holes 2 at the leading edge, the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs are all located on the middle arc F of the blade tip, and the dust removal holes 2 at the leading edge, the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs are all cylindrical holes . The distance between the inter-rib dust removal hole 3 and the upstream barrier rib 5 and the downstream barrier rib 6 is the same, and the rib height J of the upstream barrier rib 5 and the downstream barrier rib 6 is the same as the groove depth H of the groove blade top 7 . The groove depth H of the groove tip 7 is 1.1mm. The value range of the edge width W of the groove is 0.7mm. The axial chord length G of the grooved blade tip 7 is 40mm. The diameter i of the front edge dust removal hole 2 is 0.8mm. The intercostal dust removal hole 3 and the rib downstream dust removal hole 4 have an aperture diameter of 1, and the value is 1mm. The included angle between the upstream barrier rib 5 and the central axis K is α, which is 65°. The included angle between the downstream barrier rib 6 and the central axis K is β, which is 65°. The distance from the hole center of the front edge dust removal hole 2 to the front edge point is L, and the value range is 4i. The distance from the upstream barrier rib 5 to the leading edge point is m, and the value is 10i. The distance between the upstream barrier rib 5 and the downstream barrier rib 6 is M, which is 6I. The dust removal hole 4 downstream of the rib is located at a distance N downstream of the downstream barrier rib 6, and the value is 3I. In this embodiment, since the groove depth H of the grooved blade tip is relatively deep, by increasing the distance from the upstream barrier rib 5 to the leading edge point, the aerodynamic loss caused by the gap leakage flow can be effectively reduced, and at the same time, the high exchange rate near the leading edge The heat area is reduced; avoid thermal corrosion of the blade due to the high heat exchange area at the leading edge of the blade tip, and prolong the service life of the blade. The dust removal holes 2 at the leading edge, the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs can form effective air film coverage on the blade top, effectively improving the heat transfer performance of the blade top.

Embodiment two

The grooved tip structure with barrier ribs in this embodiment, by arranging upstream barrier ribs 5 and downstream barrier ribs 6 on the grooved tip 7, and respectively arranging leading edge dust removal holes 2 in the region near the leading edge of the blade tip, the upstream Between the barrier rib 5 and the downstream barrier rib 6, inter-cost dust removal holes 3 are arranged, and downstream of the downstream barrier rib 6, the rib downstream dust removal holes 4 are arranged. The dust removal holes 2 at the leading edge, the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs are all located on the middle arc F of the blade tip, and the dust removal holes 2 at the leading edge, the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs are all cylindrical holes , The distance between the intercostal dust removal hole 3 and the upstream barrier rib 5 and the downstream barrier rib 6 is the same, and the rib height J of the upstream barrier rib 5 and the downstream barrier rib 6 is the same as the groove depth H of the groove blade top 7 . The groove depth H of the groove tip 7 is 0.7mm. The value range of the edge width W of the groove is 0.6mm. The axial chord length G of the grooved blade tip 7 is 40mm. The diameter i of the front edge dust removal hole 2 is 0.8mm. The apertures of the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs are 1, and the value is 1mm. The included angle between the upstream barrier rib 5 and the central axis K is α, which is 65°. The included angle between the downstream barrier rib 6 and the central axis K is β, which is 65°. The distance from the hole center of the front edge dust removal hole 2 to the front edge point is L, and the value range is 4i. The distance m from the upstream barrier rib 5 to the leading edge point is 8i. The distance M between the upstream barrier rib 5 and the downstream barrier rib 6 is 4I. The dust removal hole 4 downstream of the rib is located at a distance N downstream of the downstream barrier rib 6, and the value is 3I. In this embodiment, since the groove depth H of the grooved blade top is relatively shallow, the distance from the upstream barrier rib to the leading edge point can be reduced, which can also reduce the aerodynamic loss caused by the gap leakage flow and reduce the high exchange rate at the leading edge. hot area. Considering that the change of the groove depth will affect the change of the leading edge high heat exchange area, in this embodiment, the distance from the leading edge dust removal hole 2 to the leading edge point is reduced, so that an effective air film can be formed in the area near the leading edge of the blade tip Covering avoids thermal corrosion of the blade due to the high heat exchange area at the leading edge of the blade tip and prolongs the service life of the blade.

Embodiment three

In the grooved tip structure with barrier ribs in this embodiment, upstream barrier ribs 5 and downstream barrier ribs 6 are arranged on the grooved tip 7, and leading edge dust removal holes 2 are respectively arranged in the area near the leading edge of the blade tip. Between the ribs 5 and the downstream barrier ribs 6, the inter-costal dust removal holes 3 are arranged, and downstream of the downstream barrier ribs 6, the rib downstream dust removal holes 4 are arranged. Among them, the dust removal hole 2 at the leading edge, the dust removal hole 3 between the ribs and the dust removal hole 4 downstream of the rib are all located on the middle arc F of the blade tip, and the dust removal hole 2 at the leading edge, the dust removal hole 3 between the ribs and the dust removal hole 4 downstream of the rib are all cylindrical The distance between the inter-rib dust removal hole 3 and the upstream barrier rib 5 and the downstream barrier rib 6 is the same, and the rib height J of the upstream barrier rib 5 and the downstream barrier rib 6 is the same as the groove depth H of the groove blade top 7 . In this embodiment, the groove depth H of the groove tip 7 is 0.8 mm. The side width W of the groove was 0.6 mm. The blade axial chord length G of the grooved blade tip 7 is 40 mm. The aperture i of the front edge dust removal hole 2 is 1.2 mm. The apertures of the dust removal holes 3 between the ribs and the dust removal holes 4 downstream of the ribs are 1, and the value is 1.2 mm. The included angle between the upstream barrier rib 5 and the central axis K is α, which is 65°. The included angle between the downstream barrier rib 6 and the central axis K is β, which is 65°. The distance L from the center of the front edge dust removal hole 2 to the front edge point is 4i. The distance m from the upstream barrier rib 5 to the leading edge point is 7i. The distance M between the upstream barrier rib 5 and the downstream barrier rib 6 is 3I. The dust removal hole 4 downstream of the rib is located at a distance N downstream of the downstream barrier rib 6, and the value is 3I. In this embodiment, further reducing the distance from the upstream barrier rib to the leading edge point can significantly reduce the aerodynamic loss caused by the leakage flow in the blade tip clearance, and at the same time reduce the high heat exchange area near the leading edge of the blade tip. Moreover, in the embodiment, the distance between the upstream barrier rib 5 and the downstream barrier rib 6 is reduced, and the apertures of the leading edge dust removal holes 2, inter-rib dust removal holes 3, and rib downstream dust removal holes 4 are increased, which can significantly improve the blade tip. The film cooling efficiency at the leading edge, center chord and trailing edge can cover most of the tip of the blade, greatly improving the heat transfer performance of the tip of the turbine blade and prolonging the service life of the blade.

Claims (2)

1. A grooved blade tip structure with barrier ribs, including turbine blades, leading edge dust removal holes, inter-rib dust removal holes, rib downstream dust removal holes, upstream barrier ribs, downstream barrier ribs, grooved blade tops, and midchord cooling channels 1. Leading edge cooling passage, characterized in that: upstream barrier ribs and downstream barrier ribs are respectively provided on the groove blade top, and leading edge dust removal holes are respectively set near the leading edge of the blade tip, and upstream barrier ribs and downstream barrier ribs The dust removal holes between the ribs are arranged in the middle, and the downstream dust removal holes of the ribs are arranged downstream of the downstream barrier ribs. , the dust removal holes between the ribs and the dust removal holes downstream of the ribs are respectively located on the middle arc of the blade tip of the groove, and the distance between the dust removal holes between the ribs and the upstream barrier rib and the downstream barrier rib is the same, the groove of the turbine blade’s groove tip The depth is the same as the rib height of the upstream barrier rib and the downstream barrier rib; The groove depth H of the grooved blade top ranges from 0.7 to 1.1 mm, the groove edge width W of the grooved blade top ranges from 0.5 to 0.7 mm, and the blade axial chord length G of the grooved blade top , the value range is 32 ~ 48mm; The front edge dust removal hole is a cylindrical hole, the front edge dust removal hole diameter i ranges from 0.8 to 1.2mm, and the distance L from the center of the front edge dust removal hole to the front edge point ranges from 3i to 5i; The dust removal holes between the ribs and the dust removal holes downstream of the ribs are cylindrical holes, and the diameter I of the dust removal holes between the ribs and the downstream dust removal holes of the ribs ranges from 1 to 1.2 mm. The distance between the dust removal holes downstream of the ribs and the downstream barrier rib N, the value range is 2I～4I; The angle α between the upstream barrier rib and the central axis ranges from 65° to 75°, and the distance m from the upstream barrier rib to the front edge point ranges from 7i to 10i. 2. The grooved blade tip structure with barrier ribs according to claim 1, wherein the distance M between the upstream barrier ribs and the downstream barrier ribs ranges from 4I to 6I.