Turbine ring assembly of gas turbine

Abstract

The invention discloses a turbine ring assembly of a gas turbine. The turbine ring assembly comprises a turbine case and a turbine outer ring arranged on the turbine case. The turbine outer ring is a rotary part formed by splicing a set of turbine outer ring fan-shaped sections, radial threaded holes are evenly distributed in the circumferential direction of the turbine case, the number of the radial threaded holes is the same as that of the turbine outer ring fan-shaped sections, a rectangular notch is formed in the turbine outer ring, radial positioning screws are arranged in the radial threaded holes, and the radial positioning screws are matched with the radial threaded holes. And the radial positioning screw can be matched with the rectangular notch. The turbine ring assembly is mainly composed of a turbine case and a turbine outer ring, the turbine case serves as an installation bearing structure and makes contact with outer side cooling gas, the inner side of the turbine outer ring makes contact with high-temperature flue gas, the fan-shaped segmented design is adopted, the turbine outer ring is installed on the turbine case, and the double-layer structure reduces the temperature gradient acting on the turbine ring assembly; gaps are formed between the fan-shaped segmented turbine outer rings, thermal stress is not prone to being generated, and the reliability of the turbine ring assembly is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine accessories, and particularly relates to a gas turbine turbine ring assembly. Background Art

[0002] As a stationary component of the turbine, the gas turbine turbine ring forms a gas flow passage and restricts gas flow. At the same time, the inner straight surface of the turbine ring assembly faces high-temperature flue gas, and the outer side communicates with the compressor cooling gas. The temperature difference between the inside and outside is very large, and the large temperature gradient brings great thermal stress. If not properly handled, it is easy to cause cracking of the turbine ring and lead to the failure of the turbine components. Therefore, the influence of thermal stress needs to be considered emphatically in the design. For this reason, the present invention proposes a new type of gas turbine turbine ring assembly. Summary of the Invention

[0003] In view of the problems existing in the prior art, the present invention proposes a gas turbine turbine ring assembly with reasonable structural settings.

[0004] The technical solution of the present invention is as follows:

[0005] A gas turbine turbine ring assembly includes a turbine casing and a turbine outer ring arranged on the turbine casing; the turbine outer ring is a rotary part formed by splicing a group of turbine outer ring fan-shaped segments. Radial threaded holes with the same number as the turbine outer ring fan-shaped segments are evenly distributed in the circumferential direction of the turbine casing. A rectangular notch is provided on the turbine outer ring. Radial positioning screws are arranged in the radial threaded holes, and the radial positioning screws can cooperate with the rectangular notch to prevent the turbine outer ring from circumferentially moving on the turbine casing, and at the same time ensure that the turbine outer ring can maintain a centering state during thermal expansion.

[0006] Further, the group of turbine outer ring fan-shaped segments are respectively clamped and arranged in the circumferential direction of the turbine casing.

[0007] Further, the turbine casing is a rotary part and is annular; an installation edge is provided on the outer side of the main body of the turbine casing for installation and connection with adjacent parts; a large-diameter annular groove A and a large-diameter annular protrusion A (the large-diameter annular protrusion A is arranged below the large-diameter annular groove A) are provided on one side of the main body of the turbine casing in the thickness direction, and a small-diameter annular groove A and a small-diameter annular protrusion A (the small-diameter annular protrusion A is arranged below the small-diameter annular groove A) are provided on the other side in the thickness direction; preferably, the large-diameter annular protrusion A and the large-diameter annular groove A are radially offset from the small-diameter annular protrusion A and the small-diameter annular groove A.

[0008] Further, on one side of the outer side of the turbine outer ring in its thickness direction, there are a large-diameter annular protrusion B and a large-diameter annular groove B (the large-diameter annular groove B is arranged at a position below the large-diameter annular protrusion B), and on the other side of its thickness direction, there are a small-diameter annular protrusion B and a small-diameter annular groove B (the small-diameter annular groove B is arranged at a position below the small-diameter annular protrusion B); preferably, the large-diameter annular protrusion B and the large-diameter annular groove B are arranged offset in the radial direction from the small-diameter annular protrusion B and the small-diameter annular groove B.

[0009] Further, the large-diameter annular groove A, the large-diameter annular protrusion A, the small-diameter annular groove A, and the small-diameter annular protrusion A on the turbine casing respectively cooperate and are snap-connected with the large-diameter annular protrusion B, the large-diameter annular groove B, the small-diameter annular protrusion B, and the small-diameter annular groove B on the turbine outer ring.

[0010] A gas turbine turbine ring assembly further includes a packing ring. An installation groove for the packing ring is provided inside the main body of the turbine casing, and the packing ring is installed in the installation groove for the packing ring to axially limit the turbine outer ring.

[0011] A gas turbine turbine ring assembly further includes a sealing sheet. Sealing sheet grooves are respectively provided on both side surfaces of the fan-shaped section of the turbine outer ring for installing the sealing sheet. The thickness of the sealing sheet is less than the groove width of the sealing sheet groove, and the width of the sealing sheet is less than the total depth formed by the sealing sheet grooves on the side surfaces of adjacent fan-shaped sections of the turbine outer ring.

[0012] Further, the radial positioning screw includes a threaded section and a cylindrical section located below the threaded section. The threaded section cooperates with the radial threaded hole, and the cylindrical section cooperates with the rectangular notch.

[0013] Further, a stop washer is installed between the turbine casing and the radial positioning screw, and the outer tongues at the edge of the stop washer are respectively bent and attached to the side surfaces of the turbine casing and the radial positioning screw to prevent the radial positioning screw from loosening.

[0014] Innovation points and corresponding technical effects of the present invention:

[0015] Innovation point 1: The gas turbine turbine ring assembly consists of a turbine casing, a turbine outer ring, a packing ring, a sealing sheet, a radial positioning screw, and a stop washer, and the entire assembly forms a unit module.

[0016] Technical effects:

[0017] 1. Through hierarchical design, the temperature gradient of the turbine ring can be reduced; the outside of the turbine casing contacts the cooling air, and the inside of the turbine outer ring contacts the high-temperature flue gas, avoiding an excessive temperature gradient on the same part.

[0018] Technical effects: 2. The turbine casing and the outer turbine ring adopt a non-fixed connection, further reducing thermal stress. Since the turbine casing and the outer turbine ring do not adopt a fixed connection method and there is a certain amount of play, large thermal stress will not occur due to the difference in thermal expansion between parts.

[0019] Technical effects: 3. The entire turbine ring assembly forms a unit body, facilitating disassembly, adjustment, replacement, and maintenance. The turbine ring assembly can be installed as a complete and independent module on the workbench and then installed as a module as a whole on the turbine component of the gas turbine. The disassembly and assembly efficiency is high, and it is convenient for adjustment, replacement, and maintenance.

[0020] Inventive point 2: The outer turbine ring adopts a segmented design, with gaps left between the fan-shaped segments. A sealing strip groove is provided on the side of the outer turbine ring, and a sealing strip is installed in the groove to seal the gap.

[0021] Technical effects:

[0022] 1. Through the segmented design of the outer turbine ring, the thermal stress on the outer turbine ring is reduced. The outer turbine ring has a uniformly distributed fan-shaped segment structure, with gaps left between the outer rings. During thermal expansion, the expansion amount in the circumferential direction is compensated through the gaps, reducing thermal stress.

[0023] 2. Through the sealing strip, the gap reserved for the expansion amount between the outer turbine rings is sealed. The path for the high-temperature flue gas to enter the outside of the outer turbine ring through the side gap is blocked by the sealing strip. At the same time, the sealing strip and the sealing strip groove are installed in a sliding manner, without affecting the release of the thermal stress of the outer turbine ring.

[0024] Inventive point 3: The outer turbine ring is radially positioned by two protrusions and grooves with different diameters in cooperation with two protrusions and grooves of the turbine casing, thermally centered by cooperating with a rectangular notch and a positioning screw, and axially limited by a packing ring.

[0025] Technical effects:

[0026] 1. Radial positioning can be achieved during the installation between the outer turbine ring and the turbine casing. The outer turbine ring and the turbine casing are matched through the short stop surfaces formed by the protrusions and grooves, and radial positioning in the installation state can be achieved. The two stop surfaces increase the reliability of centering.

[0027] 2. The installation structure of the two protrusions with different diameters is convenient for disassembly and assembly. The two protrusions are set with different diameters and are staggered in the radial position, without interfering with each other during disassembly and assembly, facilitating disassembly and assembly.

[0028] 3. Thermal centering can be achieved between the outer turbine ring and the turbine casing; the rectangular notch on the outer turbine ring mates with the cylindrical section of the radial positioning screw in the cold state. When the outer turbine ring expands due to heat, the expansion process of the outer turbine ring is restricted due to the guiding effect between the rectangular notch and the cylindrical section, and it still maintains its concentric state with the turbine casing. Therefore, thermal centering can be achieved;

[0029] 4. The axial position of the outer turbine ring is stable without axial movement; after the packing ring is snapped into the packing ring installation groove of the turbine casing, one end of it contacts the outer turbine ring, and the other end is restricted by the packing ring installation groove on the turbine casing, thus ensuring that the outer turbine ring does not have axial movement on the turbine casing;

[0030] Inventive point 4: The radial positioning screw includes a threaded section and a cylindrical section. Radial threaded holes equal in number to the outer turbine ring are evenly distributed on the turbine casing. The threaded section of the radial positioning screw is installed in the radial threaded holes on the turbine casing, and the cylindrical section mates with the rectangular notch of the outer turbine ring. The radial positioning screw is locked against loosening by a lock washer.

[0031] Technical effects:

[0032] 1. Through the radial threaded holes on the turbine casing, the radial positioning screw is connected by threads, and a radial pin (i.e., the cylindrical section) is installed on the turbine casing to ensure the thermal centering of the outer turbine ring; the pin and the screw are combined into one part. By screwing the radial positioning screw into the radial threaded holes of the turbine casing through threads, a radial pin is formed on the turbine casing. This pin mates with the rectangular notch of the outer turbine ring to guide and restrict the outer turbine ring, and thus thermal centering can be achieved;

[0033] 2. By bending the outer tongue of the lock washer, loosening of the radial positioning screw is prevented; the lock washer is installed between the radial positioning screw and the turbine casing. Its outer ring is designed with an outer tongue. By bending the outer tongue to fit with the screw head of the positioning screw and the straight edge of the turbine casing respectively, loosening of the radial positioning screw is prevented.

[0034] The beneficial effects of the present invention are as follows: The turbine ring assembly mainly consists of a turbine casing and an outer turbine ring. The turbine casing serves as the installation and load-bearing structure, contacting the outer cooling air, and the inner side of the outer turbine ring contacts the high-temperature flue gas. It adopts a fan-shaped segmented design and is installed on the turbine casing. The double-layer structure reduces the temperature gradient acting on the turbine ring assembly. There is a gap between the fan-shaped segmented outer turbine rings, which is not prone to generating thermal stress and improves the reliability of the turbine ring assembly. Brief description of the drawings

[0035] Figure 1 It is a schematic diagram of the installation structure of the turbine casing and the outer turbine ring of the present invention;

[0036] Figure 2 It is a schematic diagram of the turbine casing structure of the present invention;

[0037] Figure 3 Schematic diagram of the outer ring structure of the turbine of the present invention;

[0038] Figure 4 Schematic diagram of the radial positioning screw structure of the present invention;

[0039] Figure 5 Schematic diagram of the explosion structure of the present invention;

[0040] Figure 6 Schematic diagram of the installation structure of the stop washer of the present invention;

[0041] In the figure: 1. Turbine casing; 11. Radial threaded hole; 12. Expander ring installation groove; 13. Large-diameter annular groove A; 14. Large-diameter annular protrusion A; 15. Small-diameter annular groove A; 16. Small-diameter annular protrusion A; 2. Turbine outer ring; 21. Rectangular notch; 22. Sealing piece groove; 23. Large-diameter annular protrusion B; 24. Large-diameter annular groove B; 25. Small-diameter annular protrusion B; 26. Small-diameter annular groove B; 3. Expander ring; 4. Sealing piece; 5. Radial positioning screw; 51. Thread section; 52. Cylindrical section; 6. Stop washer. Detailed implementation manners

[0042] The following further describes the present invention with reference to the accompanying drawings of the specification.

[0043] As Figure 1 、 2 、3, 4, and 6 show, the gas turbine turbine ring assembly is composed of a turbine casing 1, a turbine outer ring 2, an expander ring 3, a sealing piece 4, a radial positioning screw 5, and a stop washer 6.

[0044] The main body of the turbine casing 1 is a rotary part. Screw holes are provided on its installation edge for installation and connection with adjacent parts. Radial threaded holes 11 equal in number to the turbine outer ring are evenly distributed in the circumferential direction for installing the radial positioning screw 5. A large-diameter annular groove A13, a large-diameter annular protrusion A14, a small-diameter annular groove A15, and a small-diameter annular protrusion A16 are designed on its inner side for installing the turbine outer ring 2. An expander ring installation groove 12 is designed on its inner side for installing the expander ring 3.

[0045] The outer ring 2 of the turbine is a sector segment of a rotating part, formed by equally dividing a machined integral ring part. The number of the outer rings 2 of the turbine is the same as the number of the radial threaded holes 11 on the turbine casing. There is a side gap reserved between the sector segments of the outer ring 2 of the turbine, which is convenient for installation and releases the radial stress during thermal expansion. A rectangular notch 21 is opened on the outer ring 2 of the turbine, which cooperates with the cylindrical section 52 of the radial positioning screw to prevent the outer ring 2 of the turbine from circumferentially moving on the turbine casing 1. At the same time, positioning is carried out through the cylindrical section 52 on the radial positioning screw 5 to ensure that the outer ring 2 of the turbine can maintain a centering state during thermal expansion. A seal piece groove 22 is opened on the side of the outer ring 2 of the turbine for installing the seal piece 4. The outer ring 2 of the turbine is provided with a large-diameter annular protrusion B23, a large-diameter annular groove B24, a small-diameter annular protrusion B25, and a small-diameter annular groove B26, which respectively cooperate with the large-diameter annular groove A13, the large-diameter annular protrusion A14, the small-diameter annular groove A15, and the small-diameter annular protrusion A16 on the turbine casing 1 to ensure the reliable installation and positioning of the outer ring 2 of the turbine on the turbine casing 1.

[0046] The main body of the piston ring 3 is a rotating part, on which a notch is opened. During installation, the piston ring 3 can be first reduced through the notch and then released from the external force after being clamped into the piston ring installation groove 12 on the turbine casing, and the piston ring is then installed into the turbine casing 1 to form an axial limit for the outer ring 2 of the turbine.

[0047] The seal piece 4 is a thin-walled sheet metal part, and its shape is the same as that of the seal piece groove 22 on the side of the outer ring of the turbine. The thickness of the seal piece 4 is less than the groove width of the seal piece groove 22 on the side of the outer ring of the turbine, and the width of the seal piece is less than the total depth formed by the seal piece grooves 22 on the side of the outer ring of the turbine at two adjacent positions, which is convenient for the installation of the seal piece 4. After the seal piece 4 is installed into the seal piece groove 22 on the side of the outer ring of the turbine, the circumferential gap between the adjacent outer rings 2 of the turbine is sealed by the seal piece 4 to prevent the high-temperature flue gas from entering the outside of the outer ring of the turbine through the circumferential gap.

[0048] The main body of the radial positioning screw 5 is a screw structure. The threaded section 51 on it is screwed into the radial threaded hole 11 on the turbine casing, and the cylindrical section 52 on it cooperates with the rectangular notch 21 on the outer ring of the turbine to perform thermal centering on the outer ring 2 of the turbine and prevent the outer ring 2 of the turbine from circumferentially moving at the same time.

[0049] The stop washer 6 is installed between the turbine casing 1 and the radial positioning screw 5. After the radial positioning screw 5 is tightened, the outer tongues at the edge of the stop washer 6 are respectively bent and pasted to the sides of the turbine casing 1 and the radial positioning screw 5 to prevent the radial positioning screw 5 from loosening.

[0050] The assembly process is as Figure 5 shown:

[0051] Step 1: First, slip the stop washer 6 onto the radial positioning screw 5, and screw the radial positioning screw 5 into the radial threaded hole 11 on the turbine casing. Bend the outer tongues of the stop washer 6 respectively to fit against the screw head of the radial positioning screw 5 and the straight edge of the turbine casing 1. Install all the radial positioning screws 5 onto the turbine casing 1 using the same method;

[0052] Step 2: All the turbine outer ring sector segments form a complete circle of the turbine outer ring 2. Insert the sealing piece 4 into the sealing piece groove 22 on the side of the turbine outer ring. Ensure that the complete circular structure formed by the turbine outer ring 2 does not come apart through a tooling, and then install it as a whole into the turbine casing 1. The large-diameter annular protrusion B23 on the turbine outer ring, the large-diameter annular groove B24 on the turbine outer ring are matched with the large-diameter annular groove A13 on the turbine casing and the large-diameter annular protrusion A14 on the turbine casing. The small-diameter annular protrusion B25 on the turbine outer ring, the small-diameter annular groove B26 on the turbine outer ring are matched with the small-diameter annular groove A15 on the turbine casing and the small-diameter annular protrusion A16 on the turbine casing. The rectangular notch 21 on the turbine outer ring is matched with the cylindrical section 51 on the radial positioning screw 5;

[0053] Step 3: Through the opening on the packing ring 3, reduce the diameter of the packing ring 3 to be smaller than the inner diameter of the installation position of the turbine casing 1, and snap the packing ring 3 into the packing ring installation groove 12 on the turbine casing. After removing the external force, the packing ring 3 is installed into the turbine casing 1, and at the same time, axially limit the turbine outer ring 2. All the parts form an independent unit assembly. The sectional view of the installed turbine ring assembly is shown in Figure 6 , and the entire turbine ring assembly can be directly installed onto the turbine component.

[0054] The above embodiments are only the preferred embodiments of the present invention and do not limit the technical solutions of the present invention. Any technical solution that can be achieved on the basis of the above embodiments without creative labor shall be regarded as falling within the scope of the patent rights of the present invention.

Claims

1. A gas turbine turbine ring assembly, characterized in that, It includes a turbine casing (1) and a turbine outer ring (2) provided on the turbine casing (1); the turbine outer ring (2) is a rotary part formed by splicing a group of turbine outer ring fan-shaped segments, and radially threaded holes (11) with the same number as the turbine outer ring fan-shaped segments are evenly distributed in the circumferential direction of the turbine casing (1). A rectangular notch (21) is provided on the turbine outer ring (2). A radial positioning screw (5) is provided in the radially threaded hole (11), and the radial positioning screw (5) can cooperate with the rectangular notch (21) to prevent the turbine outer ring (2) from circumferentially moving in the turbine casing (1), and at the same time ensure that the turbine outer ring (2) can maintain a centering state during thermal expansion.

2. The gas turbine turbine ring assembly according to claim 1, wherein, The group of turbine outer ring fan-shaped segments are respectively snap-fitted and arranged in the circumferential direction of the turbine casing (1).

3. A gas turbine turbine ring assembly according to claim 1, characterized in that, The turbine casing (1) is a rotary part and is annular; an installation edge is provided on the outer side of the main body of the turbine casing (1) for installation and connection with adjacent parts; on one side of the main body of the turbine casing (1) in its thickness direction, a large-diameter annular groove A (13) and a large-diameter annular protrusion A (14) are provided, and on the other side of its thickness direction, a small-diameter annular groove A (15) and a small-diameter annular protrusion A (16) are provided.

4. A gas turbine turbine ring assembly according to claim 3, characterized in that, On one side of the outer side of the turbine outer ring (2) in its thickness direction, a large-diameter annular protrusion B (23) and a large-diameter annular groove B (24) are provided, and on the other side of its thickness direction, a small-diameter annular protrusion B (25) and a small-diameter annular groove B (26) are provided.

5. A gas turbine turbine ring assembly according to claim 4, characterized in that, The large-diameter annular groove A (13), the large-diameter annular protrusion A (14), the small-diameter annular groove A (15), and the small-diameter annular protrusion A (16) on the turbine casing (1) are respectively snap-fitted with the large-diameter annular protrusion B (23), the large-diameter annular groove B (24), the small-diameter annular protrusion B (25), and the small-diameter annular groove B (26) on the turbine outer ring (2).

6. A gas turbine turbine ring assembly according to claim 1 or 2, characterized in that, It further includes a packing ring (3). A packing ring installation groove (12) is provided on the inner side of the main body of the turbine casing (1). The packing ring (3) is installed in the packing ring installation groove (12) to form an axial limit for the turbine outer ring (2).

7. A gas turbine turbine ring assembly according to claim 1, characterized in that, It further includes a sealing piece (4). Sealing piece grooves (22) are respectively provided on both side surfaces of the turbine outer ring fan-shaped segment for installing the sealing piece (4). The thickness of the sealing piece (4) is less than the groove width of the sealing piece groove (22), and the width of the sealing piece (4) is less than the total depth formed by the sealing piece grooves (22) on the side surfaces of adjacent two turbine outer ring fan-shaped segments.

8. A gas turbine turbine ring assembly according to claim 1, characterized in that, The radial positioning screw (5) includes a threaded section (51) and a cylindrical section (52) located below the threaded section (51). The threaded section (51) cooperates with the radially threaded hole (11), and the cylindrical section (52) cooperates with the rectangular notch (21).

9. A gas turbine turbine ring assembly according to claim 1, characterized in that, A stop washer (6) is installed between the turbine casing (1) and the radial positioning screw (5), and the outer tongues at the edge of the stop washer (6) are respectively bent and attached to the side surfaces of the turbine casing (1) and the radial positioning screw (5) to prevent the radial positioning screw (5) from loosening.

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