Bypass system manhole door

Abstract

The application discloses a bypass system manhole door, which comprises a manhole door base, a manhole passage lining plate and a manhole door cover; the manhole door base is welded to the outer wall of equipment; the manhole passage lining plate is located at the inner side of the manhole door base and comprises a main body part and a bent part; the main body part is fixed to the inner side wall of the manhole passage; the bent part is fixed to the outer end part; the manhole door cover is composed of an outer cover plate, a thermal insulation layer and an inner lining plate; the outer cover plate is opposite to the manhole door base; the inner lining plate is of a groove type structure and is fixed to the inner side of the outer cover plate; the thermal insulation layer is filled in the cavity formed by the two; the outer cover plate is connected with the outer wall of the equipment through a single hanging point suspension opening and closing device to rotate around the hanging point to open and close the manhole passage; when the manhole passage is closed, the outer cover plate is attached to the outer side of the manhole door base, the inner lining plate is embedded in the manhole passage, and sealing elements are arranged between the outer cover plate and the manhole door base, between the outer cover plate and the bent part and between the inner lining plate and the main body part to form a three-stage sealing structure, so that the sealing effect is better.

Description

Technical Field

[0001] This utility model relates to the technical field of power plant bypass systems, and in particular to manhole doors for bypass systems. Background Technology

[0002] In thermal power plants and gas-fired combined cycle power plants, the bypass system is one of the core auxiliary systems ensuring the safe and stable operation of boilers and turbines. Its core function is to allow the high-temperature, high-pressure gas generated by the turbine to be directly introduced into the atmosphere instead of being fed into the boiler during power plant startup (before the turbine reaches its rated speed / load), shutdown, or sudden load shedding (a sharp drop in grid demand). This avoids overpressure and overtemperature accidents in the turbine due to the inability to expel gas, and also reduces the impact damage to the boiler caused by sudden changes in operating conditions.

[0003] After long-term operation, two types of problems may occur inside the bypass system, requiring regular maintenance through the manhole: First, wear or aging of the sealing material may affect the sealing effect of the bypass system's sealing components; second, high-temperature linings and other components inside the equipment may detach or have their fixing bolts broken after long-term operation. Therefore, the manhole is a "maintenance passage," and its design directly determines the convenience of maintenance, sealing performance, and overall operational safety.

[0004] In existing technology, power plant manhole door structures typically include a door frame, a door panel, and an opening, closing, and fixing mechanism. The door frame is welded to the outer wall of the equipment. A sealing groove for placing a single-layer sealing gasket is opened on the inner side of the door frame to achieve a single-layer seal. Eight bolt holes are evenly distributed around the circumference of the door frame, and eight through holes are opened at the corresponding bolt hole positions on the door panel for connection and fixing via bolts. A U-shaped handle is welded to the outer side of the door panel, and two ear plates are welded to the left side of the door panel. These two ear plates are connected to two supports on the left side of the door frame via pins, forming a double-sided fixed hinge. However, this design has the following technical defects: 1. When a single-layer gasket is used for sealing, the gas temperature inside the equipment often exceeds 600℃, causing the gasket to age and crack within 3 to 6 months. This will frequently lead to the need to replace the seal and cause the surface of the leakage area to overheat. 2. The eight bolts need to be removed / tightened one by one, which cannot be done by a single person and takes more than 20 minutes in total, resulting in low maintenance efficiency; 3. The double-sided fixed hinges mean that the door panel can only be suspended above the maintenance platform after it is opened, which occupies a lot of operating space. When maintenance personnel carry tools, they are prone to bumping into the door panel, resulting in a small maintenance space. Utility Model Content

[0005] This application provides a bypass system manhole door to address at least one of the above-mentioned technical defects.

[0006] This application provides a bypass system manhole door, including a manhole door base, a manhole passage liner, and a manhole door cover; The manhole base is an annular boss structure, and the manhole base is welded to the outer wall of the equipment; The manhole channel liner has an L-shaped structure, including a main body and a bent part. The manhole channel liner is located inside the manhole door base. The main body is fixed to the inner wall of the manhole channel, and the bent part is fixed to the outer end of the manhole channel. The manhole cover consists of an outer cover plate, an insulation layer, and an inner lining plate. The outer cover plate faces the manhole base. The inner lining plate has a groove structure and is fixed to the inside of the outer cover plate. The insulation layer fills the cavity formed by the inner lining plate and the outer cover plate. The outer cover plate is connected to the outer wall of the equipment via a single hanging point suspension opening and closing device, so that the manhole passage can be opened and closed by rotating around the hanging point. When the manhole passage is closed, the outer cover plate is attached to the outside of the manhole door base, the inner liner plate is embedded in the manhole passage, and sealing elements are provided between the outer cover plate and the manhole door base, between the outer cover plate and the bent part, and between the inner liner plate and the main body, forming a three-level sealing structure.

[0007] In one possible implementation, an aluminum silicate fiber sealing strip or a metal corrugated pipe is provided between the outer cover plate and the bend.

[0008] In one possible implementation, a P-shaped belt is provided between the inner liner and the main body, and the inner liner has threaded holes evenly distributed in the circumferential direction for installing the P-shaped belt.

[0009] In one possible implementation, a double O-ring is provided between the inner liner and the main body, and the inner liner has a mounting groove in the circumferential direction for installing the double O-ring.

[0010] In one possible implementation, a ceramic fiber woven sealing strip or an expanded graphite composite gasket is provided between the outer cover plate and the manhole base.

[0011] In one possible implementation, the inner side of the outer cover plate is provided with a positioning groove at the location opposite the manhole base, and the ceramic fiber woven sealing strip or expanded graphite composite gasket is embedded in the positioning groove.

[0012] In one possible implementation, the single-point suspension opening and closing device includes a suspension support, a rotating shaft, a boom, and a lifting ring. The suspension support is fixed to any side of the top of the manhole base. The boom extends horizontally, and the outer end of the boom relative to the manhole base is connected to the suspension support via the rotating shaft. The inner end of the boom is connected to the lifting ring, and the outer cover plate is provided with a pin suitable for inserting the lifting ring.

[0013] In one possible implementation, the boom is connected to the lifting ring via an adjusting stud that extends vertically, with its upper part extending upward through the boom and an adjusting nut screwed onto the protruding portion.

[0014] In one possible implementation, multiple quick-lock structures are evenly distributed on the outer edge of the manhole base. Each quick-lock structure includes a conical handle, a T-bolt, and a positioning seat. The positioning seat is fixed to the outside of the manhole base and has a first slot suitable for engaging the T-bolt. The outer cover plate has a U-shaped hole that mates with the T-bolt. The conical handle is connected to the outer end of the T-bolt.

[0015] In one possible implementation, the manhole base and the outer cover plate are respectively embedded with adsorption magnets on their mating surfaces, the outer cover plate is provided with multiple elastic buckles on its edge, and the manhole base is provided with a second slot that cooperates with the elastic buckles.

[0016] Beneficial effects: Compared with the prior art, the bypass system manhole door provided in this application can effectively extend the sealing life and improve the sealing performance through a three-level sealing structure. At the same time, the single-point suspension opening and closing device flips the door cover to the side, which does not occupy the maintenance platform space at all, and the maintenance space is larger, which can effectively reduce the risk of collision during personnel operation. In addition, the quick-lock structure can realize the rapid opening and closing of the manhole door cover, thereby improving work efficiency. Furthermore, the combination of adsorption magnets and elastic buckles can realize the rapid locking of the manhole door cover without the need for rotation operation, making it more suitable for lightweight doors.

[0017] These and other objects, features and advantages of this utility model will be fully realized through the following detailed description. Attached Figure Description

[0018] Figure 1 The diagram shows the front view of the manhole door of the bypass system of this application.

[0019] Figure 2 A side view of the manhole door of the bypass system of this application is shown.

[0020] Figure 3 A cross-sectional structural schematic diagram of the manhole door of the bypass system of this application is shown.

[0021] Figure 4 This application shows Figure 3 A magnified structural diagram of part A in the middle.

[0022] Figure 5 This application shows Figure 3 A magnified structural diagram of part B. Detailed Implementation

[0023] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0024] Those skilled in the art should understand that, in the disclosure of this specification, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this utility model.

[0025] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0026] refer to Figures 1 to 5This application provides a bypass system manhole door, including a manhole door base 10, a manhole passage liner 20, and a manhole door cover 30. The manhole door base 10 is an annular boss structure, and is fully welded annularly to the outer wall 40 of the equipment, with a welding height of ≥5mm to ensure strength. The manhole door base 10 is concentric with the manhole passage. The manhole passage liner 20 is an L-shaped structure, including a main body 21 and a bent portion 22. The manhole passage liner 20 is located inside the manhole door base 10, wherein the main body 21 is fixed to the inner wall of the manhole passage, and the bent portion 22 is fixed to the outer end of the manhole passage. The manhole cover 30 consists of an outer cover plate 31, an insulation layer 32, and an inner lining plate 33. The outer cover plate 31 faces the manhole base 10 and can be welded from a 100x50x5 square tube (50mm thick). The inner lining plate 33 has a grooved structure and is fixed to the inside of the outer cover plate 31. The inner lining plate 33 is made of 304 stainless steel (3mm thick) and is fixed to the outer cover plate 31 by rivets (280mm spacing). The insulation layer 32 is filled in the cavity formed by the inner lining plate 33 and the outer cover plate 31. The insulation layer 32 can be filled with high-density aluminum silicate fiber cotton (density 120kg / m³, thickness depends on the medium temperature) to block the transmission of internal high temperature to the outside (reduce the surface temperature of the manhole cover to ≤60℃). The outer cover plate 31 is connected to the outer wall 40 of the equipment through a single hanging point suspension opening and closing device so that it can rotate around the hanging point to open and close the manhole passage.

[0027] When the manhole passage is closed, the outer cover plate 31 is attached to the outside of the manhole door base 10, while the inner lining plate 33 is embedded in the manhole passage. Seals are provided between the outer cover plate 31 and the manhole door base 10, between the outer cover plate 31 and the bent portion 22, and between the inner lining plate 33 and the main body portion 21, forming a three-stage sealing structure. This progressive sealing structure prevents both media leakage and noise leakage. Compared to a single-layer, single-stage sealing structure, the sealing life is significantly improved. Tests have verified that the temperature resistance is increased to over 600℃, and the sealing life is extended to over 24 months, completely blocking the leakage of media and heat.

[0028] In one embodiment, an aluminum silicate fiber sealing strip 51 or a metal bellows is provided between the outer cover plate 31 and the bend 22. The metal bellows fits against the planar sealing surface of the bend 22, and the elastic deformation of the bellows compensates for assembly errors while withstanding high-temperature erosion.

[0029] In one embodiment, a P-type belt 52 is provided between the inner liner 33 and the main body 21. The inner liner 33 is provided with threaded holes evenly distributed in the circumferential direction for installing the P-type belt 52. This allows the elasticity of the P-type belt 52 to ensure that it fits completely against the surface of the inner liner 33, blocking the primary leakage path of heat and medium.

[0030] In another embodiment, a double O-ring is provided between the inner liner 33 and the main body 21. The inner liner 33 also has a mounting groove in the circumferential direction for installing the double O-ring. The sealing band formed by the two double O-rings forms a "labyrinth seal" to block the leakage path of the medium and heat.

[0031] In one embodiment, a ceramic fiber woven sealing strip 53 or an expanded graphite composite pad is provided between the outer cover plate 31 and the manhole base 10. This allows the elastic deformation of the ceramic fiber woven sealing strip 53 to fill the tiny gaps and block the final leakage path of the medium / heat. Alternatively, the gaps can be filled by the compressibility of the expanded graphite composite pad, wherein the thickness of the expanded graphite composite pad can be 2 mm and the compression rate ≥30%.

[0032] In one embodiment, the inner side of the outer cover plate 31 is provided with a positioning groove 301 opposite to the manhole base 10, and the ceramic fiber woven sealing strip 53 or expanded graphite composite gasket is embedded in the positioning groove 301. Thus, the initial positioning between the outer cover plate 31 and the manhole base 10 can be achieved through the positioning groove 301, ensuring that the manhole base 10 can be accurately aligned when the manhole cover 30 is closed.

[0033] In one embodiment, the single-point suspension opening and closing device includes a suspension support 61, a rotating shaft 62, a boom 63, and a lifting ring 64. The suspension support 61 is fixed to either side of the top of the manhole base 10, i.e., the upper left or upper right of the manhole base 10. The boom 63 extends horizontally, and its outer end relative to the manhole base 10 is connected to the suspension support 61 via the rotating shaft 62, allowing the boom 63 to rotate on the suspension support 61 via the rotating shaft 62. The inner end of the boom 63 is connected to the lifting ring 64, and the outer cover plate 31 is provided with a pin 34 suitable for inserting the lifting ring 64. When the manhole cover 30 is opened, the manhole cover 30 rotates outward around the rotation axis under its own weight and the traction of the lifting ring 64 (maximum opening angle 170 degrees). When the manhole cover 30 is closed, the manhole cover 30 is pulled, and the positioning groove 301 cooperates with the manhole base 10 to achieve quick alignment.

[0034] In one embodiment, the boom 63 is connected to the lifting ring 64 via an adjusting stud. The adjusting stud extends vertically, with its upper part penetrating the boom 63. An adjusting nut 65 is screwed onto the protruding part, thereby adjusting the height of the lifting ring 64 by rotating the adjusting nut 65, which in turn adjusts the height of the manhole cover 30.

[0035] In one embodiment, multiple quick-lock structures are evenly distributed along the outer edge of the manhole base 10. Each quick-lock structure includes a conical handle 71, a T-bolt 72, and a positioning seat 73. The positioning seat 73 is fixed to the outside of the manhole base 10 and has a first slot suitable for engaging the T-bolt 72. The outer cover plate 31 has a U-shaped hole 302 that mates with the T-bolt 72. The conical handle 71 is connected to the outer end of the T-bolt 72. After closing the manhole cover 30, the U-shaped hole 302 on the manhole cover 30 engages with the T-bolt 72. Then, the conical handle 71 is tightened so that its bottom surface aligns with the outer cover plate 31. Continuing to rotate the conical handle 71 pulls the manhole cover 30 towards the manhole base 10, achieving rapid locking (single handle operation time ≤ 10 seconds). To open, simply rotate the conical handle 71 in the opposite direction to release the lock without disassembling the T-bolt 72.

[0036] Workflow: Initial state: Manhole cover 30 is in the open state, and the three-level sealing structure is not in contact; Alignment and positioning: Pull the manhole cover 30 and use the single hanging point suspension device to pull the manhole cover 30 toward the manhole base 10, and achieve initial positioning through the positioning groove 301; Third-level sealing: Continue to push the manhole cover 30 so that the ceramic fiber woven sealing strip 53 at the edge of the manhole cover 30 comes into contact with the sealing surface of the manhole base (initial sealing). Locking and fixing: Rotate the conical handle 71 in sequence to make the T-bolt 72 pass through the manhole cover 30 and tighten it with the conical handle 71 (at this time, the secondary seal aluminum silicate fiber sealing strip 51 fits with the bent part 22, producing a small amount of plastic deformation). First-level seal takes effect: During the pressing process of the manhole cover 30, the P-shaped strip 52 on the inner liner 33 is squeezed and embedded into the main body 21, forming a complete seal, thus achieving the closure of the manhole cover 30, and all three levels of seal take effect.

[0037] In another embodiment, the manhole door base 10 and the outer cover plate 31 are respectively embedded with magnetic attraction magnets, such as strong magnets (neodymium iron boron, attraction force ≥500N), on their mating surfaces. The outer cover plate 31 has multiple elastic buckles (not shown in the figure) along its edge, and the manhole door base 10 has a second slot that engages with the elastic buckles. Thus, when the manhole door cover 30 is closed, the magnetic attraction magnets can achieve initial positioning of the manhole door cover 30. Subsequently, the elastic buckles automatically engage with the second slot, and pressing the release button opens the door. Magnetic-assisted positioning and buckle locking eliminate the need for rotation, making it more suitable for lightweight doors.

[0038] It should be noted that the terms "first" and "second" used in this application are for descriptive purposes only and do not indicate any order. They should not be construed as indicating or implying relative importance, and can be interpreted as names.

[0039] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The advantages of the present invention have been fully and effectively realized. The functions and structural principles of the present invention have been shown and explained in the embodiments, and any modifications or variations may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. A bypass system manhole door, characterized in that, Includes manhole base, manhole passage liner and manhole cover; The manhole base is an annular boss structure, and the manhole base is welded to the outer wall of the equipment; The manhole channel liner has an L-shaped structure, including a main body and a bent part. The manhole channel liner is located inside the manhole door base. The main body is fixed to the inner wall of the manhole channel, and the bent part is fixed to the outer end of the manhole channel. The manhole cover consists of an outer cover plate, an insulation layer, and an inner lining plate. The outer cover plate faces the manhole base. The inner lining plate has a groove structure and is fixed to the inside of the outer cover plate. The insulation layer fills the cavity formed by the inner lining plate and the outer cover plate. The outer cover plate is connected to the outer wall of the equipment via a single hanging point suspension opening and closing device, so that the manhole passage can be opened and closed by rotating around the hanging point. When the manhole passage is closed, the outer cover plate is attached to the outside of the manhole door base, the inner liner plate is embedded in the manhole passage, and sealing elements are provided between the outer cover plate and the manhole door base, between the outer cover plate and the bent part, and between the inner liner plate and the main body, forming a three-level sealing structure.

2. The bypass system manhole door as described in claim 1, characterized in that, An aluminum silicate fiber sealing strip or a metal corrugated pipe is provided between the outer cover plate and the bending part.

3. The bypass system manhole door as described in claim 1, characterized in that, A P-shaped belt is provided between the inner lining plate and the main body. The inner lining plate has threaded holes evenly distributed around its circumference for installing the P-shaped belt.

4. The bypass system manhole door as described in claim 1, characterized in that, A double O-ring is provided between the inner liner and the main body. The inner liner has a mounting groove in the circumferential direction for installing the double O-ring.

5. The bypass system manhole door as described in claim 1, characterized in that, A ceramic fiber woven sealing strip or an expanded graphite composite gasket is provided between the outer cover plate and the manhole base.

6. The bypass system manhole door as described in claim 5, characterized in that, The inner side of the outer cover plate is provided with a positioning groove at the location directly opposite the manhole base, and the ceramic fiber woven sealing strip or expanded graphite composite gasket is embedded in the positioning groove.

7. The bypass system manhole door as described in claim 1 or 6, characterized in that, The single-point suspension opening and closing device includes a suspension support, a rotating shaft, a boom, and a lifting ring. The suspension support is fixed to any side of the top of the manhole base. The boom extends horizontally. The outer end of the boom relative to the manhole base is connected to the suspension support through the rotating shaft. The inner end of the boom is connected to the lifting ring. The outer cover plate is provided with a pin suitable for inserting the lifting ring.

8. The bypass system manhole door as described in claim 7, characterized in that, The boom is connected to the lifting ring via an adjusting stud. The adjusting stud extends vertically, with its upper part penetrating the boom and an adjusting nut screwed onto its protruding portion.

9. The bypass system manhole door as described in claim 1, characterized in that, Multiple quick-lock structures are evenly distributed on the outer edge of the manhole base. Each quick-lock structure includes a conical handle, a T-bolt, and a positioning seat. The positioning seat is fixed to the outside of the manhole base and has a first slot suitable for engaging the T-bolt. The outer cover plate has a U-shaped hole that mates with the T-bolt. The conical handle is connected to the outer end of the T-bolt.

10. The bypass system manhole door as described in claim 1, characterized in that, The manhole base and the outer cover plate are respectively embedded with magnetic magnets on their mating surfaces. The outer cover plate has multiple elastic buckles on its edge, and the manhole base has a second slot that cooperates with the elastic buckles.

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