Pre-swirl gas supply system and gas turbine with same

Abstract

The embodiment of the invention discloses a pre-whirl gas supply system and a gas turbine with the same. The pre-whirl air supply system comprises a pre-whirl nozzle assembly, a labyrinth disc, a turbine disc and a pressurizing impeller; the pre-whirl nozzle assembly is provided with an air supply cavity and a pre-whirl nozzle communicated with the air supply cavity; a pre-whirl cavity is defined between the labyrinth disc and the pre-whirl nozzle assembly, the pre-whirl nozzle is communicated with the pre-whirl cavity, the labyrinth disc is provided with a receiving hole, and the receiving hole is obliquely formed in the airflow rotating direction in the pre-whirl cavity relative to the end face of the labyrinth disc; a cover plate cavity is defined between the turbine disc and the labyrinth disc, the cover plate cavity is communicated with the pre-swirl cavity through a receiving hole, and the turbine disc is provided with a blade air supply channel communicated with the cover plate cavity; the pressurizing impeller is arranged in the cover plate cavity, and gas entering the cover plate cavity from the receiving hole flows into the blade gas supply channel after being pressurized by the pressurizing impeller. According to the prewhirl air supply system, the cold air amount of the turbine blades can be reduced, and the cooling effect can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of gas turbines, and in particular relates to a pre-swirl air supply system and a gas turbine having the pre-swirl air supply system. Background Art

[0002] The pre-swirl air supply system is an important part of the air system of heavy-duty gas turbines. Its function is to provide cooling air that meets the air supply pressure and flow requirements for the high-speed rotating turbine blades. In the related art, the cooling air flowing through the pre-swirl air supply system cannot reach the expected parameters required by the turbine blades due to unreasonable flow channel design, such as air flow rate, temperature drop, and supercharging effect, which increases the demand for cooling air for the gas turbine and affects the operating efficiency of the gas turbine. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention proposes a pre-swirl air supply system that can reduce the amount of cooling air for turbine blades and improve the cooling effect.

[0005] An embodiment of the present invention further provides a gas turbine.

[0006] The pre-swirl air supply system of the embodiment of the present invention comprises:

[0007] A pre-swirl nozzle assembly, the pre-swirl nozzle assembly comprising an air supply cavity and a pre-swirl nozzle connected to the air supply cavity;

[0008] A grate disc, wherein a pre-swirl chamber is defined between the grate disc and the pre-swirl nozzle assembly, the pre-swirl nozzle is connected to the pre-swirl chamber, the grate disc has a receiving hole, and the receiving hole is inclined relative to the end surface of the grate disc toward the airflow rotation direction in the pre-swirl chamber;

[0009] A turbine disc, wherein a cover plate cavity is defined between the turbine disc and the comb tooth disc, the cover plate cavity is connected to the pre-swirl cavity through the receiving hole, and the turbine disc has a blade air supply channel connected to the cover plate cavity;

[0010] A booster impeller is arranged in the cover plate cavity. The gas entering the cover plate cavity through the receiving hole flows into the blade air supply channel after being pressurized by the booster impeller.

[0011] The pre-swirl air supply system of the embodiment of the present invention can reduce the loss at the entrance of the receiving hole and improve the boosting effect by adopting an inclined receiving hole and a boosting impeller arranged in the cover plate cavity, thereby reducing the outlet pressure of the pre-swirl nozzle, improving the pressure ratio of the pre-swirl nozzle, reducing the steam supply temperature delivered to the turbine blade cooling channel, reducing the amount of cold air, and improving the cooling effect and efficiency of the gas turbine.

[0012] In some embodiments, the angle between the axis of the receiving hole and the end surface of the comb disk is greater than or equal to 20° and less than 90°.

[0013] In some embodiments, the inner radius of the boost impeller is greater than the center radius of the receiving hole.

[0014] In some embodiments, the inner radius of the boost impeller is between 0.9 and 1.1 of the airflow swirl ratio of the cover plate cavity.

[0015] In some embodiments, the receiving hole, the air flow channel of the boost impeller, and the blade air supply channel are arranged in a one-to-one correspondence.

[0016] In some embodiments, the pre-swirl nozzle is a straight hole type, a stepped hole type, or a cascade hole type.

[0017] In some embodiments, it further comprises a support ring and an intermediate shaft, wherein the intermediate shaft is arranged at the middle part of the support ring, the pre-swirl nozzle assembly is fixed on the support ring and is located between the intermediate shaft and the support ring, the support ring is provided with an air inlet communicated with the air supply chamber, a first sealing component is provided between the intermediate shaft and the pre-swirl nozzle assembly, the grate disc and the turbine disc are both connected to the intermediate shaft, a second sealing component is provided between the grate disc and the support ring, and a third sealing component is provided between the grate disc and the turbine disc;

[0018] The pre-swirl chamber is defined between the support ring, the pre-swirl nozzle assembly, the intermediate shaft and the comb-toothed disk, and the cover plate chamber is defined between the comb-toothed disk and the turbine disk.

[0019] In some embodiments, the first sealing component is a comb seal; the second sealing component includes a comb seal and a brush seal; and the third sealing component is a metal sealing rod.

[0020] The gas turbine according to the embodiment of the present invention comprises a pre-swirl air supply system, and the pre-swirl air supply system is the pre-swirl air supply system as described in any one of the above embodiments.

[0021] In some embodiments, a turbine blade is further included, wherein the turbine blade is connected to the turbine disk, and a cooling channel of the turbine blade is connected to the blade air supply channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a partial schematic diagram of the pre-swirl air supply system of an embodiment of the present invention.

[0023] Figure 2 It is a partial schematic diagram of the solidified cavity and hole in the pre-swirl air supply system of an embodiment of the present invention.

[0024] Figure 3 It is a schematic diagram of the arrangement of receiving holes of the pre-swirl air supply system of an embodiment of the present invention.

[0025] Reference numerals:

[0026] 1. Pre-swirl nozzle assembly; 11. Air supply chamber; 12. Pre-swirl nozzle;

[0027] 2. Comb tooth plate; 21. Receiving hole;

[0028] 3. Turbine disc; 31. Blade air supply channel;

[0029] 4. Pre-spin chamber;

[0030] 5. Cover plate cavity;

[0031] 6. Booster impeller;

[0032] 7. Support ring; 71. Air inlet;

[0033] 8. Intermediate shaft;

[0034] 91. First sealing component; 92. Second sealing component; 93. Third sealing component; 94. Comb seal; 95. Brush seal; 96. Metal sealing rod. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0036] A pre-swirl air supply system and a gas turbine having the same according to an embodiment of the present invention will be described below.

[0037] like Figures 1 to 3 As shown, the pre-swirl air supply system of the embodiment of the present invention includes a pre-swirl nozzle assembly 1, a comb tooth plate 2, a turbine plate 3 and a boost impeller 6.

[0038] The pre-swirl nozzle assembly 1 has an air supply cavity 11 and a pre-swirl nozzle 12 connected to the air supply cavity 11. It can be understood that the pre-swirl nozzle assembly 1 includes a shell, the air supply cavity 11 is a cavity provided in the shell, and the pre-swirl nozzle 12 is a straight hole type, a stepped hole type or a cascade hole type provided on the shell and connected to the air supply cavity 11. The airflow first enters the air supply cavity 11, and then is ejected by each pre-swirl nozzle 12 to flow downstream.

[0039] A pre-swirl chamber 4 is defined between the comb disc 2 and the pre-swirl nozzle assembly 1. The pre-swirl nozzle assembly 1 is a fixed stationary part, and the comb disc 2 is a rotating turntable. Therefore, the pre-swirl chamber 4 between the comb disc 2 and the pre-swirl nozzle assembly 1 can also be called a rotating turntable. The pre-swirl nozzle 12 is connected to the pre-swirl chamber 4. After the airflow in the air supply chamber 11 enters the pre-swirl chamber 4 through the pre-swirl nozzle 12, the airflow rotates at a high speed in the pre-swirl chamber 4. The comb disc 2 has a receiving hole 21, and the receiving hole 21 is inclined relative to the end face of the comb disc 2 toward the direction of rotation of the airflow in the pre-swirl chamber 4, so that the airflow in the pre-swirl chamber 4 is easier to enter the receiving hole 21, reduce the angle between the receiving hole 21 and the incoming flow, reduce the flow loss at the inlet of the receiving hole 21, increase the pre-swirl temperature drop, and make the swirl ratio of the airflow at the outlet of the receiving hole 21 greater than 1. Among them, the swirl ratio is the ratio of the tangential velocity of the airflow to the tangential velocity of the turntable.

[0040] A cover plate cavity 5 is defined between the turbine disc 3 and the comb disc 2. Both the turbine disc 3 and the comb disc 2 are rotating parts, and therefore, the cover plate cavity 5 can be referred to as a rotating cavity. The cover plate cavity 5 is connected to the pre-swirl cavity 4 through the receiving hole 21, and the high-speed rotating airflow in the pre-swirl cavity 4 flows into the cover plate cavity 5 after passing through the receiving hole 21. The boost impeller 6 is disposed in the cover plate cavity 5. Since the swirl ratio of the airflow in the cover plate cavity 5 gradually decreases as it flows radially outward, the gas in the cover plate cavity 5 flows into the blade air supply channel 31 after being pressurized by the boost impeller 6, which can ensure that the airflow has a sufficient swirl ratio. The turbine disc 3 has a blade air supply channel 31 connected to the cover plate cavity 5, and the airflow in the cover plate cavity 5 can be transported to the cooling channel of the turbine blade through the blade air supply channel 31.

[0041] The pre-swirl air supply system of the embodiment of the present invention can reduce the loss at the inlet of the receiving hole 21 and improve the supercharging effect by adopting an inclined receiving hole 21 and a booster impeller 6 arranged in the cover plate cavity 5, thereby reducing the outlet pressure of the pre-swirl nozzle 12, improving the pressure ratio of the pre-swirl nozzle 12, reducing the steam supply temperature delivered to the turbine blade cooling channel, reducing the amount of cold air, and improving the cooling effect and efficiency of the gas turbine.

[0042] The following describes the pre-swirl air supply system of other specific embodiments of the present invention.

[0043] like Figures 1 to 3 The pre-swirl air supply system includes a support ring 7, an intermediate shaft 8, a pre-swirl nozzle assembly 1, a comb plate 2, a turbine plate 3 and a boost impeller 6.

[0044] The support ring 7 can be connected to the cylinder body of the gas turbine, and the support ring 7 is a fixing part.

[0045] The pre-swirl nozzle assembly 1 has an air supply cavity 11 and a pre-swirl nozzle 12 connected to the air supply cavity 11. It can be understood that the pre-swirl nozzle assembly 1 includes a shell, the air supply cavity 11 is a cavity provided in the shell, and the pre-swirl nozzle 12 is a straight hole type, a stepped hole type or a cascade hole type provided on the shell and connected to the air supply cavity 11. The airflow first enters the air supply cavity 11, and then is ejected by each pre-swirl nozzle 12 to flow downstream.

[0046] The intermediate shaft 8 is arranged in the middle of the support ring 7, and the pre-swirl nozzle assembly 1 is fixed on the support ring 7 and is located between the intermediate shaft 8 and the support ring 7. The support ring 7 is provided with an air inlet 71 connected to the air supply cavity 11. A first sealing component 91 is provided between the intermediate shaft 8 and the pre-swirl nozzle assembly 1. Optionally, the first sealing component 91 is a comb tooth seal 94.

[0047] The comb disc 2 can be connected to the intermediate shaft 8, and a second sealing component 92 is provided between the comb disc 2 and the support ring 7. Optionally, the second sealing component 92 includes a comb seal 94 and a brush seal 95. A pre-swirl chamber 4 is defined between the support ring 7, the pre-swirl nozzle assembly 1, the intermediate shaft 8 and the comb disc 2. The pre-swirl nozzle assembly 1 and the support ring 7 are fixed stationary parts, and the intermediate shaft 8 and the comb disc 2 are rotating parts, so the pre-swirl chamber 4 can also be called a rotating chamber. The pre-swirl nozzle 12 is connected to the pre-swirl chamber 4. After the airflow in the air supply chamber 11 enters the pre-swirl chamber 4 through the pre-swirl nozzle 12, the airflow rotates at high speed in the pre-swirl chamber 4.

[0048] The comb tooth disc 2 has a receiving hole 21, and the receiving hole 21 is inclined relative to the end surface of the comb tooth disc 2 toward the airflow rotation direction in the pre-swirl chamber 4, so that the airflow in the pre-swirl chamber 4 can enter the receiving hole 21 more easily, reduce the angle between the receiving hole 21 and the incoming flow, reduce the flow loss at the inlet of the receiving hole 21, increase the pre-swirl temperature drop, and make the swirl ratio of the airflow at the outlet of the receiving hole 21 greater than 1. The swirl ratio is the ratio of the tangential velocity of the airflow to the tangential velocity of the rotating disk.

[0049] The angle between the axis of the receiving hole 21 and the end face of the comb disc 2 is greater than or equal to 20° and less than 90°. For example, the angle is 20°, 35°, 44°, 45°, 60°, 70° or 85°. When the angle is too small or too large, the axis direction of the receiving hole 21 will not match the airflow direction at the entrance of the receiving hole 21, affecting the rotation flow effect of the airflow entering the cover plate cavity 5, which is not conducive to the flow of the airflow in the cover plate cavity 5, and it is not easy to effectively arrange the boost impeller 6, which causes the airflow parameters entering the blade air supply channel 31 to fail to achieve the expected effect.

[0050] The turbine disc 3 is connected to the intermediate shaft 8, and a third sealing component 93 is provided between the comb disc 2 and the turbine disc 3. Optionally, the third sealing component 93 is a metal sealing rod 96. A cover plate cavity 5 is defined between the comb disc 2 and the turbine disc 3. Both the turbine disc 3 and the comb disc 2 are rotating parts, so the cover plate cavity 5 can be called a rotating cavity. The cover plate cavity 5 is connected to the pre-swirl cavity 4 through the receiving hole 21, and the high-speed rotating airflow in the pre-swirl cavity 4 flows into the cover plate cavity 5 after passing through the receiving hole 21. Therefore, the gas in the cover plate cavity 5 flows into the blade air supply channel 31 after being pressurized by the booster impeller 6, which can ensure that the airflow has a sufficient swirl ratio. The turbine disc 3 has a blade air supply channel 31 connected to the cover plate cavity 5, and the airflow in the cover plate cavity 5 can be transported to the cooling channel of the turbine blade through the blade air supply channel 31. The receiving hole 21, the airflow channel of the booster impeller 6, and the blade air supply channel 31 are arranged one by one. In the corresponding receiving hole 21 , the air flow channel of the supercharging impeller 6 , and the blade air supply channel 31 , the receiving hole 21 and the blade air supply channel 31 are respectively located at the two ends of the air flow channel of the supercharging impeller 6 .

[0051] The inner radius of the boost impeller 6 (R as shown in the figure) is greater than the central radius of the receiving hole 21. It can be understood that the dimension between the end of the boost blade of the boost impeller 6 close to the intermediate shaft 8 and the intermediate shaft 8 is greater than the dimension between the receiving hole 21 and the intermediate shaft 8. The boost impeller 6 is arranged in the cover plate cavity 5. As the airflow in the cover plate cavity 5 flows radially outward, the airflow swirl ratio gradually decreases. By setting the inner radius of the boost impeller 6 between 0.9 and 1.1 of the airflow swirl ratio of the cover plate cavity 5, the airflow swirl ratio in the cover plate cavity 5 can be increased, and the boosting effect of the boost impeller 6 can be better improved.

[0052] The inner radius of the boost impeller 6 can be at a position where the airflow swirl ratio of the cover plate cavity 5 is 0.9, 0.95, 0.98, 1, 1.05 or 1.1, so as to better boost the airflow in the cover plate cavity 5.

[0053] Taking the pre-swirl air supply system of a heavy-duty gas turbine as an example, under the premise of ensuring the air supply pressure of the turbine blades, the results of the pre-swirl air supply system in the related art and the pre-swirl air supply system in this embodiment are compared as shown in the following table:

[0054] Related technology solutions The solution of this embodiment Inclination angle a 90° 60° Radius R r1 1.1r1 Temperature drop efficiency 0.52 0.64

[0055] In the above table, the angle a between the axis of the receiving hole and the end face of the comb disc in the scheme of this embodiment is adjusted to 60°. At the same time, the inner radius R of the boost impeller is also adjusted on the original basis, so that the inner radius of the boost impeller is between 0.9 and 1.1 of the airflow swirl ratio of the cover plate cavity. Except for the receiving hole and the boost impeller, the other structures of the two pre-swirl systems are exactly the same. Through the detection and analysis of the temperature drop effect, it can be seen that this embodiment can improve the temperature drop effect by optimizing the structure of the receiving hole and the boost impeller.

[0056] The pre-swirl air supply system of the embodiment of the present invention can reduce the loss at the entrance of the receiving hole and improve the boosting effect by adopting an inclined receiving hole and a boosting impeller arranged in the cover plate cavity, thereby reducing the outlet pressure of the pre-swirl nozzle, improving the pressure ratio of the pre-swirl nozzle, reducing the steam supply temperature delivered to the turbine blade cooling channel, reducing the amount of cold air, and improving the cooling effect and efficiency of the gas turbine.

[0057] The gas turbine of the embodiment of the present invention comprises a pre-swirl air supply system and a turbine blade. The pre-swirl air supply system is a pre-swirl air supply system as in any of the above embodiments. The turbine blade is connected to the turbine disk, and the cooling channel of the turbine blade is connected to the blade air supply channel. The pre-swirl air supply system of the above embodiment is used to cool the turbine blade, reduce the required amount of cold air, improve the pressurization effect of the airflow, and improve the cooling performance of the turbine blade, thereby ensuring that the gas turbine can work stably for a long time and ensuring the efficiency of the gas turbine.

[0058] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0059] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0060] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0062] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0063] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A pre-swirl air supply system, characterized in that: include: A pre-swirl nozzle assembly, the pre-swirl nozzle assembly comprising an air supply cavity and a pre-swirl nozzle connected to the air supply cavity; A grate disc, wherein a pre-swirl chamber is defined between the grate disc and the pre-swirl nozzle assembly, the pre-swirl nozzle is connected to the pre-swirl chamber, the grate disc has a receiving hole, and the receiving hole is inclined relative to the end surface of the grate disc toward the airflow rotation direction in the pre-swirl chamber; A turbine disc, wherein a cover plate cavity is defined between the turbine disc and the comb tooth disc, the cover plate cavity is connected to the pre-swirl cavity through the receiving hole, and the turbine disc has a blade air supply channel connected to the cover plate cavity; A booster impeller is arranged in the cover plate cavity. The gas entering the cover plate cavity through the receiving hole flows into the blade air supply channel after being pressurized by the booster impeller.

2. The pre-swirl air supply system according to claim 1, characterized in that: The angle between the axis of the receiving hole and the end surface of the comb tooth disk is greater than or equal to 20° and less than 90°.

3. The pre-swirl air supply system according to claim 1 or 2, characterized in that: The inner radius of the boost impeller is greater than the central radius of the receiving hole.

4. The pre-swirl air supply system according to claim 3, characterized in that: The inner radius of the boost impeller is between 0.9 and 1.1 of the airflow swirl ratio of the cover plate cavity.

5. The pre-swirl air supply system according to claim 3, characterized in that: The receiving hole, the air flow channel of the boost impeller, and the blade air supply channel are arranged in one-to-one correspondence.

6. The pre-swirl air supply system according to claim 1, characterized in that: The pre-swirl nozzle is a straight hole type, a stepped hole type or a cascade hole type.

7. The pre-swirl air supply system according to claim 1, characterized in that: It also includes a support ring and an intermediate shaft, wherein the intermediate shaft is arranged in the middle of the support ring, the pre-swirl nozzle assembly is fixed on the support ring and is located between the intermediate shaft and the support ring, the support ring is provided with an air inlet communicated with the air supply chamber, a first sealing component is provided between the intermediate shaft and the pre-swirl nozzle assembly, the grate disc and the turbine disc are both connected to the intermediate shaft, a second sealing component is provided between the grate disc and the support ring, and a third sealing component is provided between the grate disc and the turbine disc; The pre-swirl chamber is defined between the support ring, the pre-swirl nozzle assembly, the intermediate shaft and the comb-toothed disk, and the cover plate chamber is defined between the comb-toothed disk and the turbine disk.

8. The pre-swirl air supply system according to claim 7, characterized in that: The first sealing component is a comb seal; the second sealing component includes a comb seal and a brush seal; and the third sealing component is a metal sealing rod.

9. A gas turbine, characterized in that: It comprises a pre-swirl air supply system, and the pre-swirl air supply system is the pre-swirl air supply system as claimed in any one of claims 1 to 8.

10. The gas turbine according to claim 9, characterized in that It also includes turbine blades, which are connected to the turbine disk, and the cooling channel of the turbine blades is connected to the blade air supply channel.

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