CN108798794A - A kind of wheel rim sealing structure with wavy recess and the turbine using the structure - Google Patents

Abstract

The invention provides a wheel rim seal structure with wave-like depressions and a turbine using the structure. The stationary blade is installed on the flange plate of the hub of the stationary blade, the moving blade is installed on the flange plate of the hub of the movable blade, and behind the flange plate of the hub of the stationary blade The side sealing teeth of the stator blades are arranged on the edge of the partition plate below the side, and the tops of the sealing teeth protrude radially upwards in a sickle shape. The rear side of the hub flange of the stator blades is arranged with a wave-shaped concave structure. The flow direction gradually increases, and the front side of the hub flange of the rotor blade is embedded between the hub flange of the stator blade and the sealing teeth on the side of the stator blade and arranged in a staggered manner, forming a rim seal structure with wavy depressions. The invention increases the circumferential uniformity of the airflow at the outlet of the stator blade near the end wall of the hub, reduces the demand for the minimum cooling and sealing flow of the rotor rotating disk, and at the same time directs the airflow at the outlet of the stator blade near the end wall of the hub, reducing the The possibility of gas intrusion occurs under all working conditions, and the aerodynamic efficiency of the turbine is improved.

Description

A wheel rim sealing structure with wavy depressions and a turbine using the structure

technical field

The invention relates to a turbine structure, in particular to a wheel rim sealing structure with a wave-like depression and a turbine using the structure.

Background technique

In gas turbine/aeroengine turbine components, due to the pumping effect of the turbine disc rotation, the cold air in the disc cavity will be continuously pumped out, resulting in a decrease in the airflow pressure in the sealing cavity, so under the action of the pumping effect, when the pump When the outflow flow is greater than the cold air supply flow, gas intrusion will occur at the rim of the turbine disk, that is, the mainstream gas enters the static chamber of the turbine disk cavity structure through the rim sealing structure. In addition, the mutual interference between the rotating vanes in the main flow channel will cause the circumferential pressure fluctuation of the main flow gas, which will also cause gas intrusion. Gas intrusion will destroy the cooling effect of the cavity and damage the safe and reliable operation of the gas turbine/aero engine. At present, excessive cold air is usually used in gas turbines/aero engines to prevent gas intrusion, but this will reduce the efficiency of gas turbines/aero engines and increase fuel consumption.

Rim seals are generally installed on the edge of the rotating disc cavity formed by the rotating and static components such as the turbine vane diaphragm and the rotating moving blade disc, and the rotating disc cavity formed by two coaxial rotating turbine discs. Although the existing axial and radial rim sealing structures can reduce the degree of gas intrusion to a certain extent, the effect is limited, especially under variable working conditions. Due to the deficiencies in the prior art, people always hope to have a wheel rim sealing structure which can effectively control the gas intrusion and reduce the consumption of cold air, and a turbine using the structure.

Contents of the invention

The purpose of the present invention is to greatly increase the circumferential uniformity of the airflow near the hub end wall at the outlet of the stator blade, reduce the requirement of the rotating blade rotating disk for the minimum cooling and sealing flow, and at the same time guide the outlet of the stator blade near the end wall of the hub The gas flow reduces the possibility of gas intrusion under all working conditions, improves the aerodynamic efficiency of the turbine, and provides a rim sealing structure with a wave-like depression and a turbine using the structure.

The object of the present invention is achieved in the following way: a rim seal structure with wave-shaped depressions, a wave-shaped depression structure is arranged on the rear side of the vane hub flange, the depressions are directed along the direction of the outlet angle of the stator blades, and the depth of the depressions is gradually increased along the flow direction. Increase; the front side of the hub flange plate of the movable blade is embedded between the hub flange plate of the stationary blade and the sealing teeth of the stationary blade and arranged in a staggered manner, forming a flange sealing structure with wavy depressions.

A turbine with a wavy recessed rim sealing structure, including a brake, a hub flange of a stationary blade, and a hub flange of a moving blade, a stationary blade is installed on the hub flange of the stationary blade, and a moving blade is installed on the hub flange of the moving blade. blades, the moving blades are connected to the rotating disk of the moving blades, the stationary blades are connected to the stationary vane partition, and the stationary vane partition is located under the rear side of the hub flange of the stationary vane, and the side sealing teeth of the stationary vane are arranged on the edge of the stationary vane partition. A cold flow path is formed between the stationary blade diaphragm and the moving blade rotating disk. The tops of the sealing teeth on the stationary blade side protrude radially upward in the shape of a sickle. In the direction of the air outlet angle of the stator blade, the depth of the depression increases gradually along the flow direction. The front side of the hub flange plate of the rotor blade is embedded between the hub flange plate of the stator blade and the sealing teeth of the stator blade and arranged in a staggered manner, forming a flange sealing structure with wavy depressions.

The present invention also includes such structural features:

1. The length of the wavy concave structure is 5%-15% of the chord length of the root of the stator blade.

2. The outlet width of the wavy concave structure is 1/5-1/15 of the root pitch of the stationary blade, and the outlet depth of the wavy concave structure is 0.5-2 times the thickness of the local end wall boundary layer.

Compared with the prior art, the beneficial effect of the present invention is: the present invention arranges a wave-shaped recessed structure on the rear side of the hub flange plate of the stator vane to strengthen the fluid mixing, effectively increasing the air flow near the hub end wall at the vane outlet. Circumferential uniformity, and directing the airflow near the end wall of the hub end wall at the outlet of the vane, reducing the sensitivity of the airflow direction and its circumferential uniformity to changes in working conditions, thereby reducing the possibility of gas intrusion under all working conditions. And the aerodynamic efficiency of the turbine is improved; in addition, the structure of the invention is relatively simple, the processing is also relatively convenient, and the engineering realization is easy.

Description of drawings

Figure 1 is a meridional view of a turbine with a corrugated concave structure at the outlet of the blade hub flange;

Fig. 2 is a schematic diagram of a three-dimensional structure of a wavy depression at the outlet of the hub flange of the blade;

Fig. 3 is the A direction view of Fig. 2;

Fig. 4 is a view taken along direction B of Fig. 2 .

In the figure: c is the length of the wavy concave structure, w is the outlet width of the wavy concave structure, and h is the outlet depth of the wavy concave structure.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

1-4, the present invention is made up of hub (comprising stator hub flange 3 and moving blade hub flange 4), stationary blade 1, moving blade 2 and casing (not shown in the figure). The stator blade 1 and the moving blade 2 are evenly installed in the circumferential direction between the cassettes, the stator blade 1 is in front, and the moving blade 2 is behind. The rotor blade 2 is installed on the hub flange plate 4 of the rotor blade, and is connected with the rotor blade rotating disc, forming a cold flow passage between the stationary blade partition plate 5 and the rotor blade rotating disc, and at the bottom of the rear side of the hub flange plate 3 of the stator vane The edge of the partition plate is provided with sealing teeth 6 on the side of the stationary vane. The tops of the sealing teeth protrude radially upwards in the shape of a sickle. The rear side of the hub flange of the stationary vane is arranged with a wave-shaped concave structure 7. The concave direction is along the direction of the outlet angle of the stationary vane, and the depth of the concave is along the flow direction. Gradually increasing, the forward measurement of the hub flange plate of the moving blade is embedded between the hub flange plate of the stationary blade and the sealing teeth on the side of the stationary blade and arranged in a staggered manner, forming a flange sealing structure with wavy depressions.

That is to say, the present invention provides a turbine with a wavy recessed rim sealing structure, including a casing, stationary blades, moving blades and a wheel hub, and the stationary blades and the moving blades are uniformly installed in the circumferential direction between the casing and the wheel hub, and the static The blades are in the front and the moving blades are behind. The stationary blades are installed on the hub flange of the stationary blade and connected with the diaphragm. A cold flow path is formed between the rotating disk of the moving blade, and the characteristic is that: the sealing teeth on the side of the stator blade are arranged at the edge of the partition below the rear side of the hub flange plate of the stator blade, and the tops of the sealing teeth protrude radially upwards in a sickle shape, and the stator blades The rear side of the hub flange is arranged with a wave-shaped concave structure. The concave direction is along the direction of the outlet angle of the stator blade, and the depth of the depression gradually increases along the flow direction. Arranged to form a rim seal structure with wavy depressions.

The thickness of the hub flange plate at the rear part of the stationary blade, the sealing teeth at the side of the stationary blade and the hub flange plate at the front part of the moving blade are all 2-5mm. The change rule of the depression depth along the flow direction can be linear or arc. Considering the limitation of the actual structure size, the length of the wavy concave structure is 5% to 15% of the chord length of the root of the stator blade, and the parameters of the outlet width and outlet depth of the wavy concave structure should not bring large quadratic Loss is the basis for selection. Specifically, the outlet width of the wavy concave structure is 1/5 to 1/15 of the pitch of the root of the stator blade, and the outlet depth of the wavy concave structure is 0.5 to 2 times the thickness of the local end wall boundary layer. The specific microstructure shape and optimal parameters can be obtained by means of experiments or numerical simulation methods.

Considering the radial elongation and contraction of the moving blade and the rotating disk in the transitional condition, in order to ensure the sealing performance of the rim seal, the sealing teeth on the side of the stator blade and the side of the moving blade are all along the axial length of the turbine. greater than half of the axial width of the cold runner along the turbine. From a structural point of view, in order to ensure the flow performance in the turbine end region, the hub flange at the front of the moving blade is slightly lower than the middle and rear flange, and is located below the hub flange at the rear of the stationary blade in the radial direction.

In summary, the object of the present invention is to provide a rim seal structure with wave-like depressions and a turbine using the structure, including a casing, stationary blades, moving blades and a hub. Install the stationary blade and the moving blade, the stationary blade is in the front, and the moving blade is in the rear. The stationary blade is installed on the hub flange of the stationary blade and connected with the diaphragm, and the moving blade is installed on the hub flange of the moving blade and rotates with the moving blade. The disks are connected to form a cold flow channel between the stationary blade diaphragm and the rotor blade rotating disk. The stationary blade side sealing teeth are arranged at the edge of the diaphragm below the rear side of the stator hub flange plate, and the tops of the sealing teeth protrude radially upwards to form a sickle. The rear side of the hub flange of the stator blade is arranged with a wave-shaped concave structure. The depression faces along the direction of the outlet angle of the stator blade, and the depth of the depression gradually increases along the flow direction. They are arranged alternately and alternately to form a rim sealing structure with wavy depressions. The rim seal structure with wave-like depressions and the turbine using the structure designed by the present invention increase the circumferential uniformity of the airflow near the end wall of the hub at the outlet of the stator blades, and reduce the requirement for the minimum cooling and sealing flow of the rotor blade rotating disk At the same time, the airflow near the hub end wall at the outlet of the stator blade is straightened, the possibility of gas intrusion under all working conditions is reduced, and the aerodynamic efficiency of the turbine is improved.

Claims (6)

1. a kind of wheel rim sealing structure with wavy recess, it is characterised in that：It is provided with wave on rear side of stationary blade wheel hub flange plate Wave-like sunk structure, towards along stator blade outlet angular direction, cup depth is stepped up recess along flow direction；On front side of movable vane wheel hub listrium Between embedded stationary blade wheel hub flange plate and stator blade sealing tooth and at interlaced arrangement, the wheel rim sealing knot with wavy recess is constituted Structure.

2. a kind of wheel rim sealing structure with wavy recess according to claim 1, it is characterised in that：The wave The length of shape sunk structure is the 5%-15% of stator blade blade profile root chord length.

3. a kind of wheel rim sealing structure with wavy recess according to claim 1 or 2, it is characterised in that：It is described The exit width of wavy sunk structure is the 1/5-1/15 of stator blade root pitch, and the outlet depth of wavy sunk structure is 0.5-2 times of local end wall boundary layer thickness.

4. a kind of turbine of the wheel rim sealing structure with wavy recess, including machine lock, stationary blade wheel hub flange plate, movable vane wheel hub flange Plate is equipped with stator blade on stationary blade wheel hub flange plate, movable vane piece, movable vane piece and movable vane rotating disk phase is equipped on movable vane wheel hub listrium Even, stator blade is connected with stator blade partition board, and stator blade partition board is located at below stationary blade wheel hub flange plate rear side, at the stator blade separator edge Stator blade side seal tooth is set, forms cold air runner between stator blade partition board and movable vane rotating disk, it is characterised in that：The stator blade side It is in sickle shaped that it is prominent radially upward, which to seal tooth tip, wavy sunk structure is provided on rear side of stationary blade wheel hub flange plate, be recessed direction Along stator blade outlet angular direction, cup depth is stepped up along flow direction, on front side of movable vane wheel hub listrium embedded stationary blade wheel hub flange plate with it is quiet Between leaf sealing tooth and at interlaced arrangement, the wheel rim sealing structure with wavy recess is constituted.

5. a kind of turbine of wheel rim sealing structure with wavy recess according to claim 4, it is characterised in that：Institute The length for stating wavy sunk structure is the 5%-15% of stator blade blade profile root chord length.

6. a kind of turbine of wheel rim sealing structure with wavy recess according to claim 4 or 5, feature exist In：The exit width of the wavy sunk structure is the 1/5-1/15 of stator blade root pitch, and wavy sunk structure goes out Mouth depth is 0.5-2 times of local end wall boundary layer thickness.