Hole dynamic sealing structure used in high-temperature environment and mounting method

Abstract

The invention discloses a hole dynamic sealing structure used in a high-temperature environment and an installation method, and the structure comprises a base which is fixedly connected to the surface of a cylinder body; the cover plate is provided with a second center hole with the same diameter as the first center hole; a first mounting hole is formed in the middle of the upper sealing ring; a second mounting hole with the same diameter as the first mounting hole is formed in the middle of the lower sealing ring; the two ends of the opposite crest wave spring abut against the upper sealing ring and the lower sealing ring respectively; the diameter of the probe rod is matched with the diameter of the first mounting hole and the diameter of the second mounting hole, and the probe rod penetrates through the base, the cover plate, the upper sealing ring, the lower sealing ring and the opposite vertex wave spring; when the probe rod generates transverse thermal displacement along with the cylinder body, the upper sealing ring, the lower sealing ring and the opposite vertex wave spring can move along with the probe rod, so that the sealing structure can compensate the transverse thermal displacement of the probe rod along with the cylinder body; therefore, when the probe rod vibrates along with the cylinder body, the probe rod still has reliable rod-direction sealing performance, and the sealing structure does not limit the movement of the probe rod, so that stress deformation and damage are avoided.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, specifically to a dynamic sealing structure and installation method for holes in high-temperature environments. Background Technology

[0002] Sealing structures in high-temperature environments have significant applications in aerospace, chemical, and energy fields. Sealing failure can lead to serious consequences. Taking the sealing of the probe hole in a gas turbine blade passage thermocouple (BPT) as an example, under normal circumstances, the probe is fixed to the outer cylinder of the gas turbine. During installation, it needs to penetrate the inner cylinder and extend to a designated position in the exhaust channel. Therefore, a hole structure needs to be created in the inner cylinder to ensure probe installation. Under high-temperature conditions exceeding 500℃, the BPT probe will move along with the thermal expansion of the outer cylinder. Due to the difference in thermal expansion, the relative positional relationship between the BPT probe and the inner cylinder probe hole will change. Therefore, the sealing structure at this location must simultaneously meet three major requirements: high-temperature sealing, thermal displacement compensation, and vibration resistance. If the BPT probe hole is not sealed tightly, high-temperature heat will leak and migrate to other low-temperature areas, affecting the measurement accuracy and service life of instruments in that area, and may even cause lubricating oil or electrical wiring to catch fire, resulting in unpredictable losses. When probe rods require thermal displacement compensation, mainstream sealing technology typically employs a dynamic sealing method using metal bellows. This involves encapsulating the probe with a metal bellows, with flanges at the bellows ends to seal the probe holes. This sealing method is heat-resistant and utilizes the flexibility of the metal bellows to buffer vibration and compensate for probe thermal displacement while sealing the probe holes. However, the bellows sealing structure is extremely expensive, and there is a potential risk of fatigue failure in the metal bellows during long-term operation.

[0003] Existing patents also include sealing structures for probe holes. However, these structures are either not resistant to high-temperature environments or cannot meet the thermal displacement compensation requirements of probes under high-temperature conditions.

[0004] Patent application publication number CN202011431440.4 discloses a probe sealing structure for high-pressure fluid pipelines. This structure seals high-pressure fluid leaking from the probe hole by creating a probe hole radially on the outer end face of the flange and using sealing components such as sealing cover plates and fastening cover plates, as well as sealing media such as sealing gaskets and elastic sealing rings. However, this structure completely fixes the position of the probe and cannot compensate for thermal displacement. In addition, the sealing gasket suffers from creep stress relaxation and high-temperature oxidation failure under high-temperature conditions. Therefore, this sealing structure cannot be used for hole sealing under high-temperature operating conditions.

[0005] The high-temperature dynamic sealing structure proposed in patent application publication number CN202120532673.7 can only achieve lifting and lowering sealing, i.e. rod-direction sealing, and cannot compensate for the lateral thermal displacement of the probe under high temperature environment. Otherwise, the probe will undergo forced deformation due to lateral limitation, affecting the measurement performance. Summary of the Invention

[0006] To address the above technical problems, this invention provides a dynamic sealing structure and installation method for probe holes in high-temperature environments. While sealing probe holes in high-temperature environments, the sealing structure must also ensure that it can compensate for the lateral thermal displacement of the probe rod with the cylinder body. It must also ensure that the probe rod still has reliable rod-direction sealing performance when it vibrates with the cylinder body, and the sealing structure will not restrict the movement of the probe rod to avoid stress deformation and damage.

[0007] The present invention adopts the following technical solution: A dynamic sealing structure for holes in high-temperature environments includes: a base, fixedly connected to the surface of a cylinder, having a first central hole of the same size as the hole to be sealed; a cover plate, detachably connected to the base, having a second central hole with the same diameter as the first central hole; an upper sealing ring, disposed between the base and the cover plate and attached to the lower surface of the base, having a first mounting hole in the middle; a lower sealing ring, disposed between the base and the cover plate and attached to the surface of the cover plate, having a second mounting hole in the middle with the same diameter as the first mounting hole; a counter-swing spring, with its two ends abutting against the upper and lower sealing rings respectively; and a probe rod, with a diameter adapted to the first and second mounting holes, penetrating the base, cover plate, upper sealing ring, lower sealing ring, and counter-swing spring; when the probe rod undergoes lateral thermal displacement with the cylinder, the upper sealing ring, lower sealing ring, and counter-swing spring will move together with the probe rod.

[0008] Preferably, the cover plate has a recess on the side facing the base, and the recess cooperates with the lower surface of the base to form a receiving cavity.

[0009] Preferably, the upper sealing ring and the lower sealing ring have the same diameter and are larger than the diameter of the hole to be sealed. When the probe rod undergoes lateral thermal displacement with the cylinder, the upper sealing ring, the lower sealing ring and the opposing wave spring will move together with the probe rod in the receiving cavity.

[0010] Preferably, the upper surface of the base is a sloping surface that fits the surface of the cylinder.

[0011] Preferably, the lower surface of the base is provided with a sealing groove on the outer edge, and the cover plate is provided with a sealing protrusion at a corresponding position that matches the sealing groove. The sealing groove and the sealing protrusion cooperate to form a stepped sealing structure.

[0012] Preferably, the base and the cover plate are connected by bolts.

[0013] Preferably, the surface roughness of the contact surface between the base and the upper sealing ring is Ra0.8; the surface roughness of the contact surface between the cover plate and the lower sealing ring is Ra0.8.

[0014] Preferably, the upper surface of the first mounting hole at the center of the upper sealing ring has a chamfer, and the lower surface is machined to form a first limiting groove; the second mounting hole at the center of the lower sealing ring has chamfers on both sides, and the upper surface is machined to form a second limiting groove; the two ends of the opposing wave spring abut against the first limiting groove and the second limiting groove, respectively.

[0015] Preferably, the gap between the first mounting hole, the second mounting hole, and the probe rod is 0.1 mm.

[0016] An installation method for a dynamic sealing structure for holes in high-temperature environments includes the following steps: S1: Weld and fix the base to the hole that needs to be sealed, and insert the probe rod into the hole and the base; S2: Insert the upper sealing ring, the counter-spring, the lower sealing ring, and the cover plate into the probe rod from bottom to top in sequence. The counter-spring is placed in the grooves of the upper and lower sealing rings to prevent the counter-spring from moving laterally. S3: After the through hole of the cover plate is aligned with the threaded hole of the base, screw in the bolt; after the bolt is tightened, a stepped sealing structure is formed between the base and the cover plate to prevent the external medium from entering; at the same time, the top wave spring is compressed and presses the upper sealing ring and the lower sealing ring, so that the upper sealing ring is in close contact with the base and the lower sealing ring is in close contact with the cover plate. S4: When the probe structure undergoes lateral thermal displacement with the cylinder, the upper sealing ring, the counter spring, and the lower sealing ring will move laterally with the probe rod within the receiving cavity formed by the base and the cover plate.

[0017] Compared with existing technologies, this invention has the following advantages: simplified structure, simple process, low processing and maintenance costs, and convenient assembly and disassembly; it is suitable for high-temperature environments, and creatively uses a top-mounted wave spring + sealing ring (upper and lower sealing rings) to dynamically compensate for thermal displacement under high-temperature conditions through sliding contact. The compensation performance can replace or even surpass the dynamic sealing solution of metal bellows, and will not cause fatigue cracking. In addition, this invention has good vibration resistance, and can still ensure reliable sealing even when the probe experiences rod-shaped vibration. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the dynamic sealing structure.

[0019] Figure 2 This is a cross-sectional view of the dynamic sealing structure from another perspective.

[0020] Figure 3 This is a schematic diagram of the base structure.

[0021] Figure 4 This is a schematic diagram of the cover plate.

[0022] Figure 5 This is a schematic diagram of the sealing ring and the opposing wave spring.

[0023] Figure 6 This is a streamline vector diagram for numerical simulation of a dynamic sealing structure.

[0024] Figure 7 This is a velocity contour plot for numerical simulation of a dynamic sealing structure.

[0025] In the figure, the components are: base 1, first central hole 1-1, slope surface 1-2, sealing groove 1-3, cover plate 2, second central hole 2-1, recess 2-2, sealing protrusion 2-3, upper sealing ring 3, first mounting hole 3-1, first limiting groove 3-2, lower sealing ring 4, second mounting hole 4-1, second limiting groove 4-2, bolt 5, top wave spring 6, and probe rod 7. Detailed Implementation

[0026] To facilitate understanding of the technical solution of the present invention, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0027] Example 1 like Figure 1-2 As shown, a dynamic sealing structure for holes in high-temperature environments comprises a base 1, a cover plate 2, an upper sealing ring 3, a lower sealing ring 4, hexagonal bolts 5, and opposing wave springs 6; wherein, The base 1 is welded and fixed to the surface of the cylinder body, and has a first central hole 1-1 that is the same size as the hole to be sealed to ensure sufficient thermal expansion space. The lower surface has threaded holes around the perimeter for connection with the cover plate 2 by bolts 5. The cover plate has through holes around its circumference and is fastened to the base 1 by bolts 5. It also has a second center hole 2-1 with the same diameter as the first center hole 1-1. The upper sealing ring 3 is disposed between the base 1 and the cover plate 2 and is attached to the lower surface of the base 1, and has a first mounting hole 3-1 in the middle; The lower sealing ring 4 is disposed between the base 1 and the cover plate 2 and is attached to the surface of the cover plate 2, and has a second mounting hole 4-1 in the middle with the same diameter as the first mounting hole 3-1; The two ends of the top wave spring 6 abut against the upper sealing ring 3 and the lower sealing ring 4, respectively; The diameter of the probe rod 7 is adapted to the first mounting hole 3-1 and the second mounting hole 4-1, and passes through the base 1, cover plate 2, upper sealing ring 3, lower sealing ring 4 and top wave spring 6; When the probe rod 7 undergoes lateral thermal displacement with the cylinder, the upper sealing ring 3, the lower sealing ring 4, and the opposing wave spring 6 will move together with the probe rod 7.

[0028] The cover plate 2 has a recess 2-2 on the side facing the base 1, and the recess 2-2 cooperates with the lower surface of the base 1 to form a receiving cavity.

[0029] The upper sealing ring 3 and the lower sealing ring 4 have the same diameter, which is larger than the diameter of the hole to be sealed. When the probe rod 7 undergoes lateral thermal displacement with the cylinder, the upper sealing ring 3, the lower sealing ring 4, and the opposing wave spring 6 will move together with the probe rod 7 within the receiving cavity. Under extreme conditions, this sealing structure can compensate for approximately 15mm of lateral probe displacement. Simultaneously, when the probe vibrates with the cylinder, this invention can still ensure the probe's rod-direction sealing performance and will not forcibly restrict the displacement of the probe rod 7, causing stress deformation. This invention has a simple structure, low cost, and high cost-effectiveness. Its sealing effect and thermal displacement compensation effect can completely replace the mainstream metal bellows dynamic sealing method on the market.

[0030] like Figure 3-4 As shown, the upper surface of the base 1 is a sloping surface 1-2 that fits the cylinder body surface. The outer edge of the lower surface of the base 1 is provided with a sealing groove 1-3, and the cover plate 2 is provided with a sealing protrusion 2-3 at a corresponding position that matches the sealing groove 1-3. The sealing groove 1-3 and the sealing protrusion 2-3 cooperate to form a stepped sealing structure, so as to form a tortuous sealing path and prevent external media from entering.

[0031] To ensure that the upper sealing ring 3 can slide freely, the surface roughness of the contact surface between the base 1 and the upper sealing ring 3 is Ra0.8; to ensure that the lower sealing ring 4 can slide freely, the surface roughness of the contact surface between the cover plate 2 and the lower sealing ring 4 is Ra0.8.

[0032] like Figure 5 As shown, for easy disassembly and assembly, the upper surface of the first mounting hole 3-1 at the center of the upper sealing ring 3 has a chamfer, and the second mounting hole 4-1 at the center of the lower sealing ring 4 has chamfers on both sides; and the lower surface of the first mounting hole 3-1 is machined to form a first limiting groove 3-2; the upper surface of the second mounting hole 4-1 is machined to form a second limiting groove 4-2; the two ends of the opposing wave spring 6 abut against the first limiting groove 3-2 and the second limiting groove 4-2 respectively, and the opposing wave spring 6 can also absorb the rod-direction thermal expansion of the base 1 and the cover plate 2, and has a fairly reliable self-adaptive capacity in high-temperature environments.

[0033] The upper surface of the upper sealing ring 3 is polished and ground to make sliding contact with the base 1; the lower surface of the lower sealing ring 4 is polished and ground to make sliding contact with the cover plate 2.

[0034] The diameters of the first mounting hole 3-1 and the second mounting hole 4-1 are slightly larger than the diameter of the probe rod 7. In this embodiment, the gap between the first mounting hole 3-1, the second mounting hole 4-1 and the probe rod 7 is 0.1 mm to meet the rod displacement requirements of the probe rod.

[0035] In this embodiment, dynamic sealing of 24 BPT probe holes around the gas turbine cylinder block is used as an example. This technical solution effectively solves the problem of excessive leakage at the BPT probe holes under high-temperature conditions. After dynamic sealing using the technical solution of this invention, the total leakage of the BPT probe holes is significantly reduced from 1.45 kg / s to 0.00795 kg / s. Figure 6-7 To verify the technical solution through numerical simulation, combined with Figure 6 Streamline vector graphics and Figure 7 The velocity cloud results show that the fluid flow near the sealing interface has been effectively contained by the upper sealing ring 3 and the lower sealing ring 4. In the high-pressure area, only sparse streamlines eventually flow through the physical gaps of the dynamic sealing structure to the low-pressure area.

[0036] An installation method for a dynamic sealing structure for holes in high-temperature environments includes the following steps: S1: Weld and fix the base 1 at the hole that needs to be sealed, and insert the probe rod 7 into the hole and the base 1; S2: Insert the upper sealing ring 3, the counter-sweeping spring 6, the lower sealing ring 4 and the cover plate 2 into the probe rod 7 from bottom to top in sequence. The counter-sweeping spring 6 is placed in the grooves of the upper sealing ring 3 and the lower sealing ring 4 to prevent the counter-sweeping spring 6 from moving laterally. S3: When the through hole of the cover plate 2 is aligned with the threaded hole of the base 1, screw in the bolt 5; when the bolt 5 is tightened, a stepped sealing structure is formed between the base 1 and the cover plate 2 to prevent the external medium from entering; at the same time, the top wave spring 6 is compressed and presses the upper sealing ring 3 and the lower sealing ring 4, so that the upper sealing ring 3 is in close contact with the base 1 and the lower sealing ring 4 is in close contact with the cover plate 2. S4: When the probe structure undergoes lateral thermal displacement with the cylinder, the upper sealing ring 3, the top wave spring 6, and the lower sealing ring 4 will move laterally with the probe rod 7 within the receiving cavity formed by the base 1 and the cover plate 2.

[0037] When the probe structure undergoes lateral thermal displacement with the cylinder, the upper sealing ring 3, the top wave spring 6, and the lower sealing ring 4 will move laterally with the probe rod in the cavity formed by the base 1 and the cover plate 2. Since the outer diameter of the sealing ring is larger than the diameter of the hole, the sealing structure can still achieve a reliable dynamic sealing effect when compensating for the thermal displacement of the probe.

[0038] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention shall be determined by the scope defined in the claims. Any improvements and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall also be considered as within the scope of protection of the present invention.

Claims

1. A dynamic sealing structure for holes in high-temperature environments, characterized in that, include: The base (1) is fixedly connected to the surface of the cylinder and has a first central hole (1-1) that is the same size as the hole to be sealed. The cover plate (2) is detachably connected to the base (1) and has a second center hole (2-1) with the same diameter as the first center hole (1-1). The upper sealing ring (3) is set between the base (1) and the cover plate (2) and attached to the lower surface of the base (1), and has a first mounting hole (3-1) in the middle. The lower sealing ring (4) is disposed between the base (1) and the cover plate (2) and attached to the surface of the cover plate (2), and has a second mounting hole (4-1) in the middle with the same diameter as the first mounting hole (3-1). The top wave spring (6) rests on the upper sealing ring (3) and the lower sealing ring (4) at both ends respectively; The probe rod (7) has a diameter that matches the first mounting hole (3-1) and the second mounting hole (4-1), and passes through the base (1), cover plate (2), upper sealing ring (3), lower sealing ring (4) and top wave spring (6). When the probe rod (7) undergoes lateral thermal displacement with the cylinder, the upper sealing ring (3), the lower sealing ring (4), and the opposing wave spring (6) will move together with the probe rod (7).

2. The dynamic sealing structure for holes in high-temperature environments according to claim 1, characterized in that, The cover plate (2) has a recess (2-2) on the side facing the base (1), and the recess (2-2) cooperates with the lower surface of the base (1) to form a receiving cavity.

3. The dynamic sealing structure for holes in high-temperature environments according to claim 2, characterized in that, The upper sealing ring (3) and the lower sealing ring (4) have the same diameter and are larger than the diameter of the hole to be sealed. When the probe rod (7) undergoes lateral thermal displacement with the cylinder, the upper sealing ring (3), the lower sealing ring (4) and the top wave spring (6) will move together with the probe rod (7) in the receiving cavity.

4. The dynamic sealing structure for holes in high-temperature environments according to claim 1, characterized in that, The upper surface of the base (1) is a sloping surface (1-2) that fits the surface of the cylinder.

5. The dynamic sealing structure for holes in high-temperature environments according to claim 1, characterized in that, The base (1) has a sealing groove (1-3) on the outer edge of its lower surface, and the cover plate (2) has a sealing protrusion (2-3) at the corresponding position that matches the sealing groove (1-3). The sealing groove (1-3) and the sealing protrusion (2-3) cooperate to form a stepped sealing structure.

6. The dynamic sealing structure for holes in high-temperature environments according to claim 1, characterized in that, The base (1) and the cover plate (2) are connected by bolts (5).

7. The dynamic sealing structure for holes in high-temperature environments according to claim 1, characterized in that, The surface roughness between the base (1) and the upper sealing ring (3) is Ra0.8; the surface roughness between the cover plate (2) and the lower sealing ring (4) is Ra0.

8.

8. The dynamic sealing structure for holes in high-temperature environments according to claim 1, characterized in that, The upper surface of the first mounting hole (3-1) at the center of the upper sealing ring (3) has a chamfer, and the lower surface is machined to form a first limiting groove (3-2); the second mounting hole (4-1) at the center of the lower sealing ring (4) has chamfers on both sides, and the upper surface is machined to form a second limiting groove (4-2); the two ends of the top wave spring (6) abut against the first limiting groove (3-2) and the second limiting groove (4-2) respectively.

9. The dynamic sealing structure for holes in high-temperature environments according to claim 1, characterized in that, The gap between the first mounting hole (3-1), the second mounting hole (4-1), and the probe rod (7) is 0.1 mm.

10. An installation method for a dynamic sealing structure for holes in high-temperature environments, characterized in that, Includes the following steps: S1: Weld and fix the base (1) at the hole position that needs to be sealed, and insert the probe rod (7) into the hole and the base (1). S2: Insert the upper sealing ring (3), the top wave spring (6), the lower sealing ring (4) and the cover plate (2) into the probe rod (7) from bottom to top in sequence. The top wave spring (6) is placed in the groove of the upper sealing ring (3) and the lower sealing ring (4) to prevent the top wave spring (6) from moving laterally. S3: When the through hole of the cover plate (2) is aligned with the threaded hole of the base (1), screw in the bolt (5); when the bolt (5) is tightened, a stepped sealing structure is formed between the base (1) and the cover plate (2) to prevent the external medium from entering; at the same time, the top wave spring (6) is compressed and presses the upper sealing ring (3) and the lower sealing ring (4) to make the upper sealing ring (3) and the base (1) and the lower sealing ring (4) and the cover plate (2) in close contact; S4: When the probe structure undergoes lateral thermal displacement with the cylinder, the upper sealing ring (3), the top wave spring (6) and the lower sealing ring (4) will move laterally with the probe rod (7) in the receiving cavity formed by the base (1) and the cover plate (2).

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