Differential pressure automatic rotation closed type sealing device and using method

Abstract

The invention relates to the technical field of sealing devices, and discloses a differential pressure automatic rotating closed type sealing device, which belongs to the technical field of sealing devices, and comprises a steam seal body, a hemispherical rotating arc section rotating shaft, a sealing layer, a steam seal arc section and a hemispherical rotating chamber arranged on one side in the steam seal arc section, the invention further discloses a using method of the differential pressure automatic rotating closed type sealing device. The invention has the beneficial effects of dual sealing, reduced steam leakage, improved steam turbine thermal efficiency, strong deformation resistance, stable rotation of the rotating shaft and no clamping stagnation risk; the sectional type steam seal body can be installed without disassembling the rotor, and the transformation period is short; the sealing layer is detachably connected with the rotating shaft through the T-shaped sliding groove, the whole device does not need to be dismantled during replacement, and the maintenance cost is reduced. The number of arc sections, the elastic coefficient of the spring and the brush wire density can be flexibly adjusted according to the rotor diameter and steam parameters, and the sealing device is suitable for different scenes such as a turbine high-pressure cylinder, a low-pressure cylinder and a gas turbine and is suitable for sealing upgrading and reconstruction of an existing unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing devices, in particular to a differential pressure automatic rotating closed sealing device and a use method thereof. BACKGROUND

[0002] The dynamic seal (steam seal) of a large rotating machine (such as a steam turbine and a gas turbine) is a core component for ensuring the efficiency and safe operation of the unit, which blocks the leakage of high-pressure steam to the low-pressure area and avoids direct friction between the sealing member and the rotor.

[0003] In the prior art, the traditional comb tooth type steam seal realizes sealing through a plurality of comb teeth to form a throttling gap, but is limited by the structure, has a high steam leakage, and the comb teeth are prone to wear after long-term operation, which further increases the steam leakage. Although the existing brush type steam seal has a lower steam leakage than the comb tooth type, the sealing gap is fixed and cannot be self-adaptively adjusted, and the rotor radial jump during the start and stop of the machine is prone to cause the collision and wear of the brush wire and the rotor, thereby shortening the service life. During normal operation, if the gap is too large, there is still a risk of steam leakage, and if the gap is too small, local overheating is prone to occur. SUMMARY

[0004] In view of the above problems existing in the prior art differential pressure automatic rotating closed sealing device, the present application is proposed.

[0005] Therefore, the present application aims to provide a differential pressure automatic rotating closed sealing device, which aims to: To solve the above technical problems, the present application provides the following technical scheme: A differential pressure automatic rotating closed sealing device, comprising, A steam seal body comprising a steam seal arc segment, a hemispherical rotating chamber provided on one side of the steam seal arc segment, and a spring sliding groove provided on the other side of the steam seal arc segment, the hemispherical rotating chamber being provided on the side wall of the spring sliding groove, and one group of steam seal arc segment end portions being tightly attached to another group of steam seal arc segment tail portions; A hemispherical rotating arc segment rotating shaft comprising a rotating shaft main body rotatably inserted into the hemispherical rotating chamber, a boss fixedly connected to the side wall of the rotating shaft main body, a cylindrical spring adaptively installed on the inner side of the boss, and a T-shaped sliding groove provided on the inner side of the rotating shaft main body, the end portion of the cylindrical spring being inserted into the center of the spring sliding groove, the side wall of the rotating shaft main body being tightly attached to the inside of the hemispherical rotating chamber, and the side wall of the rotating shaft main body being provided with a batten for cooperation with the side wall of the hemispherical rotating chamber; And a sealing layer fixedly connected to the inner side of the T-shaped sliding groove.

[0006] As a preferred embodiment of the differential pressure automatic rotary closing sealing device of the present invention, the sealing layer includes an inlet-side front baffle that is snapped into one side of the T-shaped slide groove, an outlet-side rear baffle that is snapped into the other side of the T-shaped slide groove, and an arc-shaped pressure plate that is sealed and inserted into the center of the T-shaped slide groove. The arc-shaped pressure plate is tightly fitted to the inner side of the inlet-side front baffle, and the arc-shaped pressure plate is disposed between the inlet-side front baffle and the outlet-side rear baffle.

[0007] As a preferred embodiment of the differential pressure automatic rotary closing sealing device of the present invention, wherein: a brush layer is fixedly connected to the inner side of the arc-shaped pressure plate, and the sidewall of the brush layer is tightly attached to the inner side of the steam outlet side rear baffle.

[0008] As a preferred embodiment of the differential pressure automatic rotary closing sealing device of the present invention, wherein: the end of the arc-shaped pressure plate is provided with a bent edge, and the end of the brush layer extends to the side wall of the bent edge of the arc-shaped pressure plate.

[0009] As a preferred embodiment of the differential pressure automatic rotary closing sealing device of the present invention, wherein: the ends of the steam inlet side front baffle and the steam outlet side rear baffle are fixedly connected by side strips, and the side strips at the ends of the steam inlet side front baffle and the steam outlet side rear baffle are encapsulated at the ends of the arc-shaped pressure plate and the brush layer.

[0010] As a preferred embodiment of the differential pressure automatic rotary closing sealing device of the present invention, wherein: the steam seal arc segment has an I-shaped structure, the side wall of the steam seal arc segment has a chamfered edge, and the end of the steam seal arc segment has an arc surface.

[0011] As a preferred embodiment of the differential pressure automatic rotary closing sealing device of the present invention, wherein: a positioning pin mounting hole is provided at the end of the steam seal arc segment, and the positioning pin mounting hole is symmetrically arranged on the side wall of the end of the steam seal arc segment.

[0012] As a preferred embodiment of the differential pressure automatic rotary closing sealing device of the present invention, wherein: the side wall of the steam seal arc segment is provided with a comb plate, the side wall of the comb plate is provided with an inclined structure, and the end of the arc-shaped pressure plate extends to the middle of the comb plate.

[0013] As a preferred embodiment of the present invention, the inner wall of the steam seal arc segment is provided with a stepped groove structure that cooperates with the boss, and the stepped groove of the inner wall of the steam seal arc segment is provided on the side wall of the spring slide groove.

[0014] A method for using a differential pressure automatic rotary sealing device includes the following steps: Step 1: Preparations before installation Component integrity and specification verification Check all components of the device: steam seal arc segment, hemispherical rotating arc segment shaft, sealing layer, and cylindrical spring, to ensure there is no deformation, cracks, or brush bristle detachment; Confirm key dimensions: The radius of the hemispherical rotating chamber of the gas seal arc segment matches the main body of the rotating shaft, and the diameter of the locating pin mounting hole is adapted to the locating pin; Step 2: Assembling the steam seal and fixing the unit Gas seal arc segments spliced ​​into a complete circle Each steam seal arc segment is joined end to end in the circumferential direction so that the end arc surfaces of adjacent arc segments are in close contact. Align the locating pin mounting hole at the end of the arc segment, insert the locating pin, and ensure the coaxiality of the entire circle; The arc-shaped spliced ​​flange is fastened with high-temperature alloy bolts, and a high-temperature graphite gasket is embedded in the flange sealing groove to prevent steam leakage at the splice. The steam seal body is fixed to the unit's steam seal groove. The assembled steam seal body is hoisted into the steam seal groove on the outside of the unit rotor, so that the positioning boss on the outside of the steam seal arc is flush with the steam seal groove to ensure coaxiality during installation. Secure the steam seal body to the unit cylinder block with bolts. Tighten the bolts to the required torque according to the unit manual to avoid over-tightening and deformation of the steam seal arc. Step 3: Assemble the hemispherical rotating arc segment shaft and sealing layer. Hemispherical rotating arc segment pivot installation High-temperature grease is applied to the inner wall of the spring groove in the steam seal arc section, and one end of the cylindrical spring is inserted into the boss of the rotating shaft body. Align the hemispherical surface of the shaft body with the hemispherical rotating chamber of the steam seal arc section, and slowly push it in until the boss contacts the stepped groove at the bottom of the spring slide groove to ensure that the shaft rotates flexibly. Check the clearance between the side strip of the main body of the rotating shaft and the side strip groove of the hemispherical rotating chamber; Sealing layer snap-fit ​​and sealing inspection Align the front baffle on the inlet side and the rear baffle on the outlet side of the sealing layer with the T-shaped groove of the rotating shaft body, push them into the groove to the bottom, and lock them in place by the elastic buckle at the end of the groove. Confirm the assembly status of the sealing layer: the arc-shaped pressure plate is attached to the front baffle on the steam inlet side, the brush layer is attached to the rear baffle on the steam outlet side, and the end strips seal the arc-shaped pressure plate and the brush layer without loosening or misalignment. Step 4: Initial Post-Installation Check (Verification in Shutdown State) Sealing gap measurement Use a feeler gauge to measure the gap between the sealing layer and the simulated rotor (or the actual rotor) to ensure that the gap meets the set range when the machine is stopped. Check the relative position of the comb plate and the sealing layer to ensure that the end of the arc-shaped pressure plate extends to the middle of the comb plate to form a double sealing structure. Component flexibility test Manually push the main body of the rotating shaft to confirm that it rotates smoothly around the hemispherical rotating chamber and that the cylindrical spring extends and retracts without any jamming. Check the ability of the sealing layer to make minor adjustments along the T-slot to compensate for installation errors; Step 5: Start-up and Adaptive Adjustment of Operating Conditions Initial shutdown / startup Before starting the unit, ensure that the cylindrical spring is in its naturally extended state and that the sealing gap is maintained; Start the unit and observe the rotor radial runout (using the unit vibration monitoring instrument) to ensure that the sealing layer does not collide with the rotor. Transitional operating conditions As the steam flow rate increases, observe the rotation state of the sealing layer: the steam impacts the inclined surface of the arc-shaped pressure plate, driving the main body of the rotating shaft to rotate clockwise, and the sealing gap gradually decreases; The unit's steam flow monitoring system confirmed that the gap adjustment was synchronized with the flow change, without any jamming or sudden gap changes. Normal operating conditions After the steam flow stabilizes, the sealing layer rotates to its maximum angle, the bristle layer fits tightly against the rotor surface, and the sealing gap is reduced. Monitor the steam leakage of the unit (through a steam leakage monitoring device) to ensure that the steam leakage and the unit's thermal efficiency meet the design requirements; Step Six: Handling Abnormal Operating Conditions (Vibration / Flow Fluctuation) sudden vibration of rotor When the unit's vibration detector shows that the vibration value exceeds the limit, observe whether the sealing layer automatically retracts (the spring force pushes the rotating shaft, increasing the gap) to avoid the brush layer colliding with the rotor. If the vibration continues, stop the machine and check the rotor balance. After eliminating the abnormality, restart the machine. Steam flow rate drops sharply When the flow rate drops suddenly, the cylindrical spring automatically pushes the shaft to rotate, restoring the sealing gap to its normal state and preventing wear of the seals caused by the rotor's cooling and contraction. Once the flow rate stabilizes, the device automatically re-enters the transitional operating condition for adjustment. Step 7: Routine Maintenance and Parts Replacement Regular inspection After stopping the machine, use a feeler gauge to measure the sealing gap. If the gap is greater than the specified value during normal operation, check the wear of the bristle layer (if the wear exceeds the limit, it needs to be replaced). Check the spring force of the cylindrical spring and whether there is any wear on the inner wall of the spring groove; Replace the sealing layer (without disassembling the entire device). Press the elastic buckle at the end of the T-shaped slide to unlock the sealing layer and pull out the old sealing layer along the groove opening; Clean the inside of the T-shaped groove (wipe the dustproof groove with a cleaning cloth dampened with anhydrous ethanol), install the new sealing layer and lock it; After replacement, measure the stop gap, and start the machine after confirming that the assembly is correct.

[0015] The beneficial effects of this invention are: double sealing reduces steam leakage, improves turbine thermal efficiency, enhances resistance to deformation, ensures stable shaft rotation, and eliminates the risk of jamming; the segmented steam seal body can be installed without disassembling the rotor, shortening the modification cycle; the sealing layer is detachably connected to the shaft via a T-shaped groove, eliminating the need to remove the entire device during replacement, thus reducing maintenance costs. The number of arc segments, spring elasticity coefficient, and brush density can be flexibly adjusted according to rotor diameter and steam parameters, adapting to different scenarios such as high-pressure cylinders, low-pressure cylinders, and gas turbines, while also being suitable for sealing upgrades of existing units. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Fig. 1 This is a schematic diagram of the overall structure of the present invention; Fig. 2 This is a side view perspective three-dimensional structural diagram of the present invention; Fig. 3 This is a front view of the present invention. Fig. 4 This is a schematic diagram of the vapor seal structure of the present invention; Fig. 5 This is a schematic diagram of the hemispherical rotating arc segment shaft structure of the present invention; Fig. 6 This is a schematic diagram of the sealing layer structure of the present invention.

[0017] In the diagram: 100, steam seal body; 101, steam seal arc segment; 102, hemispherical rotating chamber; 103, spring groove; 104, locating pin mounting hole; 105, comb plate; 200, hemispherical rotating arc segment shaft; 201, shaft body; 202, boss; 203, cylindrical spring; 204, T-shaped groove; 300, sealing layer; 301, steam inlet side front baffle; 302, steam outlet side rear baffle; 303, arc-shaped pressure plate; 304, brush layer. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0019] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0020] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0021] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0022] Example 1 Reference Figs. 1-6 The first embodiment of the present invention provides a differential pressure automatic rotary closing sealing device, which includes: The steam seal body 100 includes a steam seal arc segment 101, a hemispherical rotating chamber 102 formed on one side inside the steam seal arc segment 101, and a spring groove 103 provided on the other side inside the steam seal arc segment 101. The hemispherical rotating chamber 102 is provided on the side wall of the spring groove 103. The ends of one set of steam seal arc segments 101 are tightly fitted with the tails of another set of steam seal arc segments 101. The hemispherical rotating arc segment shaft 200 includes a shaft body 201 rotatably inserted into the hemispherical rotating chamber 102, a boss 202 fixedly connected to the side wall of the shaft body 201, a cylindrical spring 203 adapted to be installed inside the boss 202, and a T-shaped groove 204 provided inside the shaft body 201. The end of the cylindrical spring 203 is inserted into the center of the spring groove 103. The side wall of the shaft body 201 is tightly fitted to the inside of the hemispherical rotating chamber 102, and the side wall of the shaft body 201 is provided with a side strip that cooperates with the side wall of the hemispherical rotating chamber 102.

[0023] The steam seal body 100 is formed by splicing multiple steam seal arc segments 101 end to end to form a complete circular ring, adapting to different rotor diameters. Each steam seal arc segment 101 is integrally milled. A hemispherical rotating chamber 102 is formed on the inner side of the steam seal arc segment 101. The hemispherical rotating chamber 102 and the rotating shaft 200 of the hemispherical rotating arc segment form a spherical fit, providing a certain range of rotational freedom for the rotating shaft body 201. The side wall of the hemispherical rotating chamber 102 is provided with side strips and side strip grooves, which fit with the side strips of the rotating shaft body 201 to restrict the axial movement of the rotating shaft body 201. The spring groove 103 and the boss 202 form a limiting fit to prevent the cylindrical spring 203 from being over-compressed, and at the same time, it can guide the cylindrical spring 203 and keep the cylindrical spring 203 in place. 203 is stably extended and retracted at the center of the spring slide groove 103; the hemispherical rotating arc segment shaft 200 realizes the angle adjustment of the sealing layer 300 through spherical rotation, and transmits elastic force and steam pressure at the same time. The hemispherical surface of the shaft body 201 is coated with a wear-resistant coating and is clearance-fitted with the hemispherical rotating chamber 102, which ensures the flexibility of rotation and reduces the steam leakage channel; the bosses 202 are evenly distributed around the circumference of the shaft body 201, usually 4-6, and are interference-fitted with the columnar spring 203 to ensure stable transmission of spring force; the T-shaped slide groove 204 has an anti-detachment structure on the inner side, the groove opening width is smaller than the groove bottom width, and forms a "sliding + snap" connection with the sealing layer 300, allowing the sealing layer 300 to be adjusted slightly in the radial direction to compensate for installation errors.

[0024] And a sealing layer 300 fixedly connected to the inner side of the T-shaped groove 204.

[0025] Specifically, the sealing layer 300 includes an inlet-side front baffle 301 that is snapped into one side of the T-shaped slide 204, an outlet-side rear baffle 302 that is snapped into the other side of the T-shaped slide 204, and an arc-shaped pressure plate 303 that is sealed and inserted into the center of the T-shaped slide 204. The arc-shaped pressure plate 303 is tightly fitted to the inside of the inlet-side front baffle 301 and is located between the inlet-side front baffle 301 and the outlet-side rear baffle 302.

[0026] The composite-designed sealing layer 300 combines force transmission and sealing functions. Its modular structure allows for easy replacement. The ends of the steam inlet side front baffle 301 and the steam outlet side rear baffle 302 are welded together to form a closed frame, which encapsulates the arc-shaped pressure plate 303 and the brush layer 304 to prevent the components from falling off due to high-speed steam flow. The arc-shaped pressure plate 303 has an inclined structure on its steam-facing surface, which can convert the steam flow pressure into a clockwise rotational torque (the magnitude of the torque is positively correlated with the steam flow rate), driving the sealing layer to move closer to the rotor.

[0027] Furthermore, a bristle layer 304 is fixedly connected to the inner side of the arc-shaped pressure plate 303. The sidewall of the bristle layer 304 is tightly attached to the inner side of the steam outlet rear baffle 302. A bent edge is provided at the end of the arc-shaped pressure plate 303. The end of the bristle layer 304 extends to the bent edge sidewall of the arc-shaped pressure plate 303. The ends of the steam inlet front baffle 301 and the steam outlet rear baffle 302 are fixedly connected by edge strips, and the edge strips at the ends of the steam inlet front baffle 301 and the steam outlet rear baffle 302 are encapsulated in the ends of the arc-shaped pressure plate 303 and the bristle layer 304.

[0028] The bristle layer 304 is fixed to the inner side of the arc-shaped pressure plate 303, and its free end extends to the bending edge of the arc-shaped pressure plate 303, forming a "rigid support + flexible sealing" structure to avoid excessive deformation of the bristles.

[0029] It should be noted that the steam seal arc segment 101 has an I-shaped structure, the side wall of the steam seal arc segment 101 has a chamfered edge, and the end of the steam seal arc segment 101 has an arc surface.

[0030] Among them, the 101 I-shaped cross-section design of the steam seal arc section can increase the strength of the base material while making the base material lightweight, and can withstand the impact of high-pressure steam within a set range without deformation.

[0031] Preferably, a positioning pin mounting hole 104 is provided at the end of the steam seal arc segment 101, and the positioning pin mounting holes 104 are symmetrically arranged on the side wall at the end of the steam seal arc segment 101.

[0032] Among them, the adjacent arc segments of the steam seal arc segment 101 are tightly fitted at the ends, and the positioning pin is inserted into the positioning pin mounting hole 104 for positioning, ensuring the coaxiality of the whole circle and avoiding steam leakage at the splice.

[0033] Specifically, the side wall of the steam seal arc segment 101 is provided with a comb plate 105, the side wall of the comb plate 105 is provided with a slope structure, and the end of the arc-shaped pressure plate 303 extends to the middle of the comb plate 105.

[0034] Among them, the comb plate 105 integrally formed on the side wall of the steam seal arc segment 101 has a bevel at the end of the tooth surface. The comb plate 105 has two heights, which are staggered to form a double barrier of "main seal + comb tooth auxiliary seal" with the sealing layer 300, reducing the risk of steam leakage.

[0035] Preferably, the inner wall of the steam seal arc segment 101 is provided with a stepped groove structure that cooperates with the boss 202, and the stepped groove of the inner wall of the steam seal arc segment 101 is provided on the side wall of the spring slide groove 103.

[0036] The spring slide groove 103 has a stepped groove structure at its end, which forms a limiting fit with the boss 202 to prevent the cylindrical spring 203 from being over-compressed.

[0037] During operation, a brush layer 304 is installed on the rear side of the arc-shaped pressure plate 303. During initial shutdown or startup (when steam flow is less than 10%), the columnar springs 203 on the sidewall of the sealing layer 300 are in a normal supporting state, allowing the gap between the sealing layer 300 and the rotor to reach its maximum value (approximately 3-4 mm). This effectively prevents radial runout of the rotor during startup and shutdown, minimizing the vibration and disturbance caused by steam flow. As the steam flow increases (10%-30% of the design flow), the steam pressure gradually increases as it passes through the side of the arc-shaped pressure plate 303, generating a closing force that overcomes the spring force. This causes the sealing layer 300 to rotate automatically in the direction of steam flow, gradually reducing the sealing gap. Under normal operating conditions (steam flow greater than 30%), the fully sealed sealing layer rotates to its maximum angle, achieving complete sealing and maintaining the minimum design gap.

[0038] In summary, the small sealing gap during normal operation, combined with the double seal of brush filaments and comb teeth, reduces steam leakage and improves turbine thermal efficiency. Through dynamic balance between pressure differential and spring force, it adapts to various operating conditions and extends service life. The I-shaped steam seal arc segment has strong anti-deformation capabilities, and the spherical fit and edge strip limiting design ensure stable shaft rotation without the risk of jamming. The segmented steam seal body can be installed without disassembling the rotor, resulting in a short modification cycle. The sealing layer is detachably connected to the shaft via a T-shaped sliding groove, eliminating the need to dismantle the entire device during replacement and reducing maintenance costs. The number of arc segments, spring elasticity coefficient, and brush filament density can be flexibly adjusted according to rotor diameter and steam parameters. The steam leakage of this pressure differential automatic rotary closing seal is only 10%-20% of the original comb-tooth steam seal. It can withstand speeds exceeding 305 m / s and temperatures up to 690℃, ensuring long-term, stable, and safe operation. It is suitable for use as a dynamic seal in large rotor mechanical equipment and is compatible with various scenarios such as high-pressure cylinders, low-pressure cylinders, and gas turbines. It is also suitable for upgrading existing unit seals.

[0039] Example 2 Reference Figs. 1-6 This is a second embodiment of the present invention, which differs from the first embodiment in that it provides a method for using a differential pressure automatic rotary closing sealing device, comprising the following steps: Step 1: Pre-installation preparation (checking compatible units and components) Component integrity and specification verification Check all components of the device: steam seal arc segment 101 (3-8 segments depending on the rotor diameter, e.g., 3 segments for a 500mm rotor, 8 segments for a 3000mm rotor), hemispherical rotating arc segment shaft 200 (quantity matches the steam seal arc segment), sealing layer 300 (including inlet side front baffle 301, outlet side rear baffle 302, arc-shaped pressure plate 303, brush bristle layer 304), and cylindrical spring 203 (elastic coefficient 5-10N / mm, 8-10N / mm for high-pressure cylinder, 5-7N / mm for low-pressure cylinder), ensuring no deformation, cracks, or brush bristle detachment; Confirm key dimensions: The radius (10-20mm) of the hemispherical rotating chamber 102 of the steam seal arc segment 101 matches the rotating shaft body 201, and the diameter (6-8mm) of the locating pin mounting hole 104 is adapted to the locating pin.

[0040] Preparation of tools and accessories Prepare the following installation tools: Allen wrench (M6-M12), locating pin (fitting mounting hole 104), feeler gauge (0.02-4mm, used to measure the gap), high-temperature grease (temperature resistance ≥600℃, to be applied to the inner wall of spring groove 103); Prepare sealing accessories: high-temperature graphite gasket (compatible with gas seal arc segment splicing flange), cleaning cloth (wipe the component surface with anhydrous ethanol to remove oil and impurities).

[0041] Step 2: Assembling the steam seal and fixing the unit Gas seal arc segments spliced ​​into a complete circle Each steam seal arc segment 101 is fitted end to end in the circumferential direction so that the end arc surfaces of adjacent arc segments are in close contact. Align the locating pin mounting hole 104 at the end of the arc segment, insert the locating pin (fitting clearance 0.02-0.05mm), and ensure that the coaxiality of the entire circle is ≤0.05mm; The arc-shaped spliced ​​flange is fastened with M8-M12 high-temperature alloy bolts, and a high-temperature graphite gasket (compression amount 20%-30%) is embedded in the flange sealing groove to prevent steam leakage at the splice.

[0042] The steam seal body is fixed to the unit's steam seal groove. The assembled steam seal body 100 is hoisted to the steam seal groove on the outside of the unit rotor, so that the positioning boss (3mm high) on the outside of the steam seal arc segment 101 is 0.05-0.1mm away from the steam seal groove to ensure coaxiality during installation. Secure the steam seal body 100 to the unit cylinder block with bolts. Tighten the bolts to the torque required by the unit manual (usually 20-30 N·m) to avoid overtightening and causing deformation of the steam seal arc.

[0043] Step 3: Assemble the hemispherical rotating arc segment shaft and sealing layer. Hemispherical rotating arc segment pivot installation High-temperature grease is applied to the inner wall of the spring groove 103 of the steam seal arc section 101, and one end of the cylindrical spring 203 is inserted into the boss 202 of the rotating shaft body 201 (interference 0.01-0.03mm). Align the hemispherical surface of the rotating shaft body 201 with the hemispherical rotating chamber 102 of the steam seal arc section, and slowly push it in until the boss 202 contacts the stepped groove at the bottom of the spring slide groove 103 to ensure that the rotating shaft rotates flexibly (without jamming, and the rotation angle is ≥30°). Check the clearance (0.03-0.06mm) between the side strip of the rotating shaft body 201 and the side strip groove of the hemispherical rotating chamber 102, and limit the axial movement to ≤0.1mm.

[0044] Sealing layer snap-fit ​​and sealing inspection Align the front baffle 301 on the steam inlet side and the rear baffle 302 on the steam outlet side of the sealing layer 300 with the T-shaped slide groove 204 of the rotating shaft body 201, push them into the bottom along the groove, and lock them by the elastic buckle at the end of the slide groove (press the buckle until you hear a "click" sound). Confirm the assembly status of the sealing layer: the arc-shaped pressure plate 303 is attached to the front baffle 301 on the steam inlet side, the brush layer 304 is attached to the rear baffle 302 on the steam outlet side, and the end strips encapsulate the arc-shaped pressure plate and the brush layer without loosening or misalignment.

[0045] Step 4: Initial Post-Installation Check (Verification in Shutdown State) Sealing gap measurement Use a feeler gauge to measure the gap between the sealing layer 300 and the simulated rotor (or the actual rotor) to ensure that the gap is 3-4mm when the machine is stopped (the radial runout of the adapted rotor is ≤3mm). Check the relative position of the comb plate 105 and the sealing layer 300 to ensure that the end of the arc-shaped pressure plate 303 extends to the middle of the comb plate 105 to form a double sealing structure.

[0046] Component flexibility test Manually push the rotating shaft body 201 to confirm that it rotates smoothly around the hemispherical rotating chamber 102 and that the cylindrical spring 203 extends and retracts without jamming. Check the minor adjustment capability (±0.2mm) of the sealing layer 300 along the T-shaped groove 204 to compensate for installation errors.

[0047] Step 5: Start-up and Adaptive Adjustment of Operating Conditions Initial shutdown / start-up phase (steam flow rate < 10% of design value) Before starting the unit, confirm that the column spring 203 is in a naturally extended state and the sealing gap is maintained at 3-4mm; Start the unit and observe the rotor radial runout (using the unit vibration detector) to ensure that the sealing layer does not collide with the rotor (vibration value ≤ 0.05 mm).

[0048] Transitional operating conditions (10% ≤ steam flow rate < 30% of design value) As the steam flow rate increases, observe the rotation state of the sealing layer 300: the steam impacts the inclined surface of the arc-shaped pressure plate 303, driving the rotating shaft body 201 to rotate clockwise, and the sealing gap gradually decreases to 0.5-1mm; The unit's steam flow monitoring system confirmed that the gap adjustment was synchronized with the flow change, without any jamming or sudden gap changes.

[0049] Normal operating conditions (steam flow rate ≥ 30% of design value) After the steam flow stabilizes, the sealing layer rotates to its maximum angle, and the 304 bristle layer fits tightly against the rotor surface, reducing the sealing gap to 0.05-0.20mm (0.05-0.12mm for the high-pressure cylinder and 0.12-0.20mm for the low-pressure cylinder). Monitor the steam leakage of the unit (through a steam leakage monitoring device) to ensure that the steam leakage is 10%-20% of that of a traditional comb-type steam seal, and that the unit's thermal efficiency meets the design requirements.

[0050] Step Six: Handling Abnormal Operating Conditions (Vibration / Flow Fluctuation) Sudden rotor vibration (>3mm) When the unit's vibration detector shows that the vibration value exceeds the limit, observe whether the sealing layer 300 automatically retracts (the spring force pushes the rotating shaft, increasing the gap) to avoid the brush layer colliding with the rotor. If the vibration continues, stop the machine and check the rotor balance. After eliminating the abnormality, restart the machine.

[0051] Steam flow rate drops sharply (<10% of design value) When the flow rate drops suddenly, the cylindrical spring 203 automatically pushes the rotating shaft to rotate, and the sealing gap is restored to 3-4mm to prevent wear of the seals caused by the cooling and contraction of the rotor; Once the flow rate stabilizes, the device will automatically re-enter the transitional operating condition for adjustment.

[0052] Step 7: Routine Maintenance and Parts Replacement Regular inspections (every 3000 hours) After stopping the machine, use a feeler gauge to measure the sealing gap. If the gap is >0.2mm during normal operation, check the wear of the 304 brush bristle layer (if the wear is >30%, it needs to be replaced). Check the spring force of cylindrical spring 203 (by testing the compression amount; if the compression amount is greater than 50% of the free length, it needs to be replaced), and check for wear on the inner wall of spring groove 103.

[0053] Replace the sealing layer (without disassembling the entire device). Press the elastic buckle at the end of the T-shaped slide 204 to unlock the sealing layer 300 and pull out the old sealing layer along the groove opening; Clean the inside of the T-shaped groove (wipe the dustproof groove with a cleaning cloth dampened with anhydrous ethanol), install the new sealing layer and lock it; After replacement, measure the stopping gap (3-4mm), and start the machine after confirming that the assembly is correct.

[0054] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0055] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0056] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A differential pressure automatic rotary closing sealing device, characterized in that: include, The steam seal body (100) includes a steam seal arc segment (101), a hemispherical rotating chamber (102) formed on one side inside the steam seal arc segment (101), and a spring groove (103) provided on the other side inside the steam seal arc segment (101). The hemispherical rotating chamber (102) is provided on the side wall of the spring groove (103). The ends of one set of steam seal arc segments (101) are tightly fitted with the tails of another set of steam seal arc segments (101). The hemispherical rotating arc segment pivot (200) includes a pivot body (201) rotatably inserted into the hemispherical rotating chamber (102), a boss (202) fixedly connected to the side wall of the pivot body (201), a cylindrical spring (203) adapted to be installed inside the boss (202), and a T-shaped groove (204) provided inside the pivot body (201). The end of the cylindrical spring (203) is inserted into the center of the spring groove (103). The side wall of the pivot body (201) is tightly fitted to the inside of the hemispherical rotating chamber (102), and the side wall of the pivot body (201) is provided with a side strip that cooperates with the side wall of the hemispherical rotating chamber (102). And a sealing layer (300) fixedly connected to the inner side of the T-shaped groove (204).

2. The differential pressure automatic rotary closing sealing device according to claim 1, characterized in that: The sealing layer (300) includes an inlet-side front baffle (301) snapped into one side of the T-shaped groove (204), an outlet-side rear baffle (302) snapped into the other side of the T-shaped groove (204), and an arc-shaped pressure plate (303) sealed and inserted into the center of the T-shaped groove (204). The arc-shaped pressure plate (303) is tightly fitted to the inside of the inlet-side front baffle (301), and the arc-shaped pressure plate (303) is located between the inlet-side front baffle (301) and the outlet-side rear baffle (302).

3. The differential pressure automatic rotary closing sealing device according to claim 2, characterized in that: A bristle layer (304) is fixedly connected to the inner side of the arc-shaped pressure plate (303), and the sidewall of the bristle layer (304) is tightly attached to the inner side of the steam outlet side rear baffle (302).

4. The differential pressure automatic rotary closing sealing device according to claim 3, characterized in that: The arc-shaped pressure plate (303) has a bent edge at its end, and the brush layer (304) extends to the side wall of the bent edge of the arc-shaped pressure plate (303).

5. The differential pressure automatic rotary closing sealing device according to claim 4, characterized in that: The ends of the steam inlet side front baffle (301) and the steam outlet side rear baffle (302) are fixedly connected by side strips, and the side strips at the ends of the steam inlet side front baffle (301) and the steam outlet side rear baffle (302) are encapsulated at the ends of the arc-shaped pressure plate (303) and the brush layer (304).

6. The differential pressure automatic rotary closing sealing device according to claim 5, characterized in that: The steam seal arc segment (101) has an I-shaped structure, the side wall of the steam seal arc segment (101) is provided with a chamfered edge, and the end of the steam seal arc segment (101) is provided with an arc surface.

7. The differential pressure automatic rotary closing sealing device according to claim 6, characterized in that: The end of the steam seal arc segment (101) is provided with a positioning pin mounting hole (104), and the positioning pin mounting hole (104) is symmetrically arranged on the side wall of the end of the steam seal arc segment (101).

8. The differential pressure automatic rotary closing sealing device according to claim 7, characterized in that: The side wall of the gas seal arc segment (101) is provided with a comb plate (105), the side wall of the comb plate (105) is provided with a slope structure, and the end of the arc-shaped pressure plate (303) extends to the middle of the comb plate (105).

9. The differential pressure automatic rotary closing sealing device according to claim 8, characterized in that: The inner wall of the steam seal arc segment (101) is provided with a stepped groove structure that cooperates with the boss (202), and the stepped groove of the inner wall of the steam seal arc segment (101) is provided on the side wall of the spring slide groove (103).

10. A method of using the differential pressure automatic rotary closing sealing device according to claim 9, characterized in that: Includes the following steps: Step 1: Preparations before installation Component integrity and specification verification Check all components of the device: steam seal arc segment, hemispherical rotating arc segment shaft, sealing layer, and cylindrical spring, to ensure there is no deformation, cracks, or brush bristle detachment; Confirm key dimensions: The radius of the hemispherical rotating chamber of the gas seal arc segment matches the main body of the rotating shaft, and the diameter of the locating pin mounting hole is adapted to the locating pin; Step 2: Assembling the steam seal and fixing the unit Gas seal arc segments spliced ​​into a complete circle Each steam seal arc segment is joined end to end in the circumferential direction so that the end arc surfaces of adjacent arc segments are in close contact. Align the locating pin mounting hole at the end of the arc segment, insert the locating pin, and ensure the coaxiality of the entire circle; The arc-shaped spliced ​​flange is fastened with high-temperature alloy bolts, and a high-temperature graphite gasket is embedded in the flange sealing groove to prevent steam leakage at the splice. The steam seal body is fixed to the unit's steam seal groove. The assembled steam seal body is hoisted into the steam seal groove on the outside of the unit rotor, so that the positioning boss on the outside of the steam seal arc is flush with the steam seal groove to ensure coaxiality during installation. Secure the steam seal body to the unit cylinder block with bolts. Tighten the bolts to the required torque according to the unit manual to avoid over-tightening and deformation of the steam seal arc. Step 3: Assemble the hemispherical rotating arc segment shaft and sealing layer. Hemispherical rotating arc segment pivot installation High-temperature grease is applied to the inner wall of the spring groove in the steam seal arc section, and one end of the cylindrical spring is inserted into the boss of the rotating shaft body. Align the hemispherical surface of the shaft body with the hemispherical rotating chamber of the steam seal arc section, and slowly push it in until the boss contacts the stepped groove at the bottom of the spring slide groove to ensure that the shaft rotates flexibly. Check the clearance between the side strip of the main body of the rotating shaft and the side strip groove of the hemispherical rotating chamber; Sealing layer snap-fit ​​and sealing inspection Align the front baffle on the inlet side and the rear baffle on the outlet side of the sealing layer with the T-shaped groove of the rotating shaft body, push them into the groove to the bottom, and lock them in place by the elastic buckle at the end of the groove. Confirm the assembly status of the sealing layer: the arc-shaped pressure plate is attached to the front baffle on the steam inlet side, the brush layer is attached to the rear baffle on the steam outlet side, and the end strips seal the arc-shaped pressure plate and the brush layer without loosening or misalignment. Step 4: Initial Post-Installation Check (Verification in Shutdown State) Sealing gap measurement Use a feeler gauge to measure the gap between the sealing layer and the simulated rotor (or the actual rotor) to ensure that the gap meets the set range when the machine is stopped. Check the relative position of the comb plate and the sealing layer to ensure that the end of the arc-shaped pressure plate extends to the middle of the comb plate to form a double sealing structure. Component flexibility test Manually push the main body of the rotating shaft to confirm that it rotates smoothly around the hemispherical rotating chamber and that the cylindrical spring extends and retracts without any jamming. Check the ability of the sealing layer to make minor adjustments along the T-slot to compensate for installation errors; Step 5: Start-up and Adaptive Adjustment of Operating Conditions Initial shutdown / startup Before starting the unit, ensure that the cylindrical spring is in its naturally extended state and that the sealing gap is maintained; Start the unit and observe the rotor radial runout (using the unit vibration monitoring instrument) to ensure that the sealing layer does not collide with the rotor. Transitional operating conditions As the steam flow rate increases, observe the rotation state of the sealing layer: the steam impacts the inclined surface of the arc-shaped pressure plate, driving the main body of the rotating shaft to rotate clockwise, and the sealing gap gradually decreases; The unit's steam flow monitoring system confirmed that the gap adjustment was synchronized with the flow change, without any jamming or sudden gap changes. Normal operating conditions After the steam flow stabilizes, the sealing layer rotates to its maximum angle, the bristle layer fits tightly against the rotor surface, and the sealing gap is reduced. Monitor the steam leakage of the unit (through a steam leakage monitoring device) to ensure that the steam leakage and the unit's thermal efficiency meet the design requirements; Step Six: Handling Abnormal Operating Conditions (Vibration / Flow Fluctuation) sudden vibration of rotor When the unit's vibration detector shows that the vibration value exceeds the limit, observe whether the sealing layer automatically retracts (the spring force pushes the rotating shaft, increasing the gap) to avoid the brush layer colliding with the rotor. If the vibration continues, stop the machine and check the rotor balance. After eliminating the abnormality, restart the machine. Steam flow rate drops sharply When the flow rate drops suddenly, the cylindrical spring automatically pushes the shaft to rotate, restoring the sealing gap to its normal state and preventing wear of the seals caused by the rotor's cooling and contraction. Once the flow rate stabilizes, the device automatically re-enters the transitional operating condition for adjustment. Step 7: Routine Maintenance and Parts Replacement Regular inspection After stopping the machine, use a feeler gauge to measure the sealing gap. If the gap is greater than the specified value during normal operation, check the wear of the bristle layer (if the wear exceeds the limit, it needs to be replaced). Check the spring force of the cylindrical spring and whether there is any wear on the inner wall of the spring groove; Replace the sealing layer (without disassembling the entire device). Press the elastic buckle at the end of the T-shaped slide to unlock the sealing layer and pull out the old sealing layer along the groove opening; Clean the inside of the T-shaped groove (wipe the dustproof groove with a cleaning cloth dampened with anhydrous ethanol), install the new sealing layer and lock it; After replacement, measure the stop gap, and start the machine after confirming that the assembly is correct.

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