Natural ventilation direct air cooling steam exhaust pipeline support compensation system and method

Abstract

The invention discloses a natural ventilation direct air cooling steam exhaust pipeline supporting compensation system and method, and belongs to the technical field of power plant air cooling systems. A mother pipe spring and damper combined support is arranged at the position, close to a steam exhaust port of a steam turbine, of a mother pipe; the mother pipe guide sliding bracket and the mother pipe sliding bracket are respectively used for guiding axial sliding and providing vertical support; the main pipe spring bracket is used for providing elastic support; in the connecting area of the mother pipe and the annular pipe, axial thermal expansion generated by the mother pipe section subsystem is accumulated and shows as axial thrust; the axial thrust is received and converted into the effect of restraining tangential displacement of the annular pipe and guiding the annular pipe to expand in the radial direction through the annular pipe guiding sliding support, and the pi-shaped pipeline compensation structure is used for absorbing composite displacement accumulated at the tail end of the annular pipe in the guiding process. The defects of structural stability, displacement adaptability, wind resistance, shock resistance and the like of a traditional thin-wall large-diameter steam exhaust pipeline adopting a traditional supporting compensation mode are overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power plant air cooling system, and particularly relates to a natural ventilation direct air cooling exhaust pipe supporting and compensating system and method. BACKGROUND

[0002] The natural ventilation direct air cooling technology is a key cooling scheme for solving the bottleneck of large-scale thermal power plant construction in coal-rich and water-deficient areas. The core of the technology lies in its huge exhaust pipe system, which is responsible for transporting the high-temperature exhaust steam (about 80℃) discharged by the steam turbine to the air cooling condenser at the top of the air cooling tower. To meet the requirement of large-flow transportation, the exhaust pipe system usually has the characteristics of large diameter (up to several meters), long line, complex structure (including riser, horizontal main pipe, multi-stage annular distribution pipe, etc.), and needs to withstand significant thermal expansion caused by high temperature, wind load, earthquake action and other multiple complex loads. To reduce the self-weight, the exhaust pipe of the natural ventilation direct air cooling system usually adopts thin-walled and large-diameter design, which results in low radial stiffness and poor overall stability, so that the support and thermal displacement compensation of the pipe become key technical problems that restrict the safe and reliable operation of the system.

[0003] At present, the existing exhaust pipe is led out from the top of the turbine house, vertically rises through a large-diameter elbow, and is connected with the steam distribution pipe above through a horizontal pipe. For such pipes, the existing support system usually adopts traditional rigid supports (such as fixed supports, guide supports, sliding supports) or constant force spring supports. In order to support the huge weight of the pipe and medium, a large number of such supports are usually densely arranged at key positions to form a discrete support system. In order to absorb the axial and lateral expansion of the pipe caused by heating, the most common solution at present is to install metal bellows expansion joints (such as general type, hinge type or pressure balance type expansion joints) on the vertical or horizontal sections of the pipe system, and rely on the flexible deformation of the bellows to compensate for the displacement and reduce the thermal stress.

[0004] However, the above support and compensation scheme has the following inherent defects when facing the large-diameter thin-walled pipe unique to the natural ventilation direct air cooling system: (1) the support mode does not match the pipe wall stiffness, and the risk of local stress concentration is high: the point or linear rigid constraint of the traditional support acts on the thin-walled pipe, which will produce extremely high local contact stress, and is extremely easy to induce local buckling of the pipe wall.

[0005] (2) insufficient deformation constraint capacity for large-diameter pipes, poor anti-seismic and anti-wind performance Large-diameter thin-walled pipelines are prone to ovalization deformation and negative pressure buckling. The existing discrete support system lacks overall constraint and can only limit displacement, and cannot provide effective ring stiffness reinforcement. Under the action of strong wind or earthquake, the huge wind load and inertia force will cause the pipeline to produce severe low-frequency vibration or overall sway, and the rigid support cannot buffer these energies, which is easy to cause the root of the support to tear or the pipeline to fatigue failure. (3) The compensation system is bulky and poor in economy: a plurality of large-diameter bellows expansion joints are connected in series to absorb large displacement, which not only has huge initial investment, but also requires a large number of heavy fixed piers and complex secondary fixed support systems to balance the huge pressure thrust generated, which occupies a large space and is not flexible in layout. In addition, the bellows itself has low stiffness under large-diameter working conditions, and there is a risk of instability, vibration and fatigue leakage, with high long-term maintenance cost, and the overall adaptability and reliability of the system are insufficient.

[0006] In summary, the existing support compensation scheme has systemic deficiencies in terms of support stability, displacement adaptability, dynamic reliability and economy in dealing with the specific object of the natural ventilation direct air cooling exhaust pipeline. Therefore, there is an urgent need for a new support and thermal displacement compensation solution to fundamentally ensure the long-term, safe, stable and efficient operation of such generating units. SUMMARY

[0007] The purpose of the present application is to overcome the problems in the prior art, provide a natural ventilation direct air cooling exhaust pipeline support compensation system and method, which can effectively manage the complex displacement of the pipeline in three-dimensional space, release thermal stress, absorb vibration, and ensure the long-term stable operation of the entire air cooling exhaust pipeline system by optimizing the configuration and system integration of different functional supports and compensators.

[0008] The present application provides a natural ventilation direct air cooling exhaust pipeline support compensation system, which is used to connect the exhaust port of a steam turbine and an air cooling condenser, and comprises a mother pipe and a plurality of ring pipes connected thereto, comprising: A mother pipe segment subsystem, which comprises a mother pipe spring and damper combined support, a mother pipe guide sliding support, a mother pipe sliding support, a mother pipe spring support, a large rod compensator and a hinge type compensator; the mother pipe spring and damper combined support is arranged at the position close to the exhaust port of the steam turbine on the mother pipe, for providing elastic support in the vertical direction and damping in the horizontal direction; the mother pipe guide sliding support and the mother pipe sliding support are arranged at intervals along the long straight section of the mother pipe, for guiding axial sliding and constraining transverse displacement respectively, and providing vertical support; the mother pipe spring support is arranged at the connection area of the mother pipe and the ring pipe, for providing elastic support at the node and adjusting local load; the large rod compensator is arranged on the long straight section of the exhaust mother pipe, for absorbing the axial displacement of the mother pipe; the hinge type compensator is arranged in groups at the corners of the mother pipe, for absorbing the angular thermal displacement of the mother pipe; a ring pipe guiding sliding support is arranged for each stage of the ring steam distribution pipe, and the guiding direction is set to be radially pointing to the geometric center of the stage of the ring pipe; a π type pipe compensation structure is arranged at the end of the last stage of the ring steam distribution pipe; In the connection area of the mother pipe and the ring pipe, the axial thermal expansion generated by the mother pipe segment subsystem is accumulated and expressed as an axial thrust; the ring pipe segment subsystem receives and converts the axial thrust into a constraint of the tangential displacement of the ring pipe and guides the radial expansion of the ring pipe through the ring pipe guiding sliding support, and the π type pipe compensation structure is used to absorb the composite displacement accumulated at the end of the ring pipe in the guiding process.

[0009] Preferably, the mother pipe spring support is located directly below the tee structure connected between the mother pipe and the first stage of the ring pipe; the first ring pipe guiding sliding support of the first stage of the ring pipe is installed adjacent to the interface of the tee structure on the ring pipe, and the preset ring pipe guiding direction is perpendicular to the axial center line of the mother pipe at the interface in the horizontal plane.

[0010] Preferably, the mother pipe spring and damper combined support comprises a support box support, at least one spring assembly and at least one damper; one end of the spring assembly and the damper is connected to the bottom of the support box support, and the other end is connected to the support foundation through the pre-embedded part of the top of the support foundation; wherein the spring assembly bears the vertical load of the mother pipe at the position, the damper bears the horizontal load of the mother pipe at the position, and the mother pipe is located in the support box support.

[0011] Preferably, the mother pipe guiding sliding support also comprises a support box support and a support foundation; the adjusting steel plate is connected to the support foundation of the mother pipe guiding sliding support through the pre-embedded part, and the polytetrafluoroethylene plate is arranged between the support column of the support box support and the adjusting steel plate; the mother pipe guiding sliding support further comprises a limiting structure, and the limiting structure is used to constrain the axial displacement of the pipe.

[0012] Preferably, the π type pipe compensation structure comprises a horizontal top pipe, two vertical stand pipes and a horizontal bottom pipe, and the connection between the vertical stand pipe and the horizontal top pipe and the horizontal bottom pipe is a 45° beveled pipe segment.

[0013] Preferably, the polytetrafluoroethylene plate is arranged between the sliding surfaces of the mother pipe sliding support and the ring pipe guiding sliding support.

[0014] Preferably, a hinged compensator is arranged on the vertical section and the horizontal section of the exhaust branch pipe.

[0015] The application also provides a method for using the natural ventilation direct air cooling exhaust pipe support compensation system, comprising: At the position of the mother pipe near the steam turbine exhaust port, a mother pipe spring and damper combined support is arranged to provide vertical elastic support and inhibit transient vibration caused by rapid impact such as earthquake, wind vibration, water hammer and the like; Along the long straight section of the exhaust mother pipe, the mother pipe guide sliding support and the mother pipe sliding support are arranged at intervals to guide axial sliding and constrain lateral displacement; and the large rod compensator is arranged on the long straight section, and the hinge type compensator is arranged in groups at the bend to respectively absorb axial and angular thermal displacement; A plurality of annular pipe guide sliding supports are arranged for each stage of annular steam distribution pipe, and the sliding direction thereof is set to be radially directed to the geometric center of the stage of annular pipe; and a π-shaped pipe compensation structure is arranged at the end of the last stage of annular steam distribution pipe; A mother pipe spring support is arranged at the connection area of the mother pipe and the annular pipe; and axial thermal displacement of the mother pipe section can be converted into driving and guiding force for radial expansion of the annular pipe, and end displacement of the annular pipe is absorbed by the π-shaped pipe compensation structure.

[0016] Preferably, in the exhaust mother pipe section, flexible support under static load and rigid locking under dynamic load are realized by the mother pipe spring and damper combined support; axial displacement is absorbed by the large rod compensator, and angular displacement is absorbed by the hinge type compensator in groups; ordered release of axial displacement and maintenance of lateral stability are realized by the interval arrangement of the mother pipe guide sliding support and the mother pipe sliding support; in the annular pipe section, tangential displacement of the pipe is constrained by the annular pipe guide sliding support when the pipe is heated, and the pipe is guided to expand along the preset radial direction; axial, lateral and angular composite displacement accumulated at the end of the annular pipe due to the radial expansion is absorbed by the π-shaped pipe compensation structure.

[0017] Compared with the prior art, the beneficial effects of the present application are: the present application aims at the problems of complex thermal displacement of thin-walled large-diameter exhaust pipe, fragmentation and low efficiency of traditional support and compensation mode in the natural ventilation direct air cooling system, and through targeted support and compensation design of the mother pipe section and the annular pipe section, the mother pipe spring and damper combined support, the mother pipe guide sliding support, the mother pipe sliding support, the mother pipe spring support, the annular pipe guide support and the π-shaped pipe are accurately arranged at the specific mechanical nodes of the pipe, so that these components not only bear clear special functions such as support, guidance, vibration reduction and displacement absorption, but also form an organic whole which can automatically convert axial thermal expansion of the mother pipe into controlled radial expansion of the annular pipe and manage and consume multi-dimensional displacement and vibration in the whole process, solving the problems of structural stability, displacement adaptability, wind and earthquake resistance, economy and maintenance of thin-walled large-diameter exhaust pipe using traditional support and compensation mode. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The whole plane schematic view of the exhaust steam pipeline combination support and thermal displacement compensation system of the present application.

[0019] Figure 2 The vertical structure schematic view of the thermal displacement compensation system on the exhaust steam pipeline branch pipe of the present application.

[0020] Figure 3 The axial schematic view of the mother pipe spring and damper combination support of the present application.

[0021] Figure 4 The structure schematic view of the A-A place of the mother pipe spring and damper combination support of the present application.

[0022] Figure 5 The structure schematic view of the B-B place of the mother pipe guiding sliding support of the present application.

[0023] Figure 6 The structure schematic view of the C-C place of the mother pipe sliding support of the present application.

[0024] Figure 7 The structure schematic view of the D-D place of the mother pipe spring support of the present application.

[0025] Figure 8 The structure schematic view of the ring pipe guiding sliding support of the present application.

[0026] Figure 9 The structure schematic view of the π type pipe of the present application.

[0027] Explanation of reference signs: 10 - steam turbine exhaust port; 20 - air cooling condenser inlet; 1 - mother pipe spring and damper combination support; 2 - mother pipe guiding sliding support; 3 - mother pipe sliding support; 4 - mother pipe spring support; 5 - first stage ring pipe guiding sliding support; 6 - second stage ring pipe guiding sliding support; 7 - third stage ring pipe guiding sliding support; 8 - fourth stage ring pipe guiding sliding support; 11 - mother pipe large pull rod compensator; 12 - mother pipe hinge type compensator; 13 - first stage exhaust branch pipe hinge type compensator; 14 - second stage exhaust branch pipe hinge type compensator; 15 - π type pipe.

[0028] 101 - mother pipe pipeline A place; 102 - spring element A place; 103 - damper element; 104 - welded pin seat; 105 - damper thrust device; 106 - support box support A place; 107 - mother pipe support foundation A place; 108 - mother pipe support foundation top pre-set embedded part A place.

[0029] 201 - at the pipe B; 202 - at the B adjusting steel plate; 203 - at the B PTFE plate; 204 - at the B limiting block; 205 - at the B bracket box support; 206 - at the B pipe bracket foundation; 207 - at the top of the B pipe bracket foundation preset embedded parts.

[0030] 301 - at the pipe C; 302 - at the C adjusting steel plate; 303 - at the C PTFE plate; 304 - at the C bracket box support; 305 - at the C pipe bracket foundation; 306 - at the top of the C pipe bracket foundation preset embedded parts.

[0031] 401 - at the pipe D; 402 - at the D spring element; 403 - at the D limiting block; 404 - at the D bracket box support; 405 - at the D pipe bracket foundation; 406 - at the top of the D pipe bracket foundation preset embedded parts.

[0032] 501 - at the pipe of each level annular pipe; 502 - at the annular pipe adjusting steel plate; 503 - at the annular pipe PTFE plate; 504 - at the annular pipe limiting block; 505 - at the annular pipe bracket box support; 506 - at the annular pipe bracket foundation; 507 - at the top of the annular pipe bracket foundation preset embedded parts.

[0033] 151 - horizontal top pipe; 152 - vertical standpipe; 153 - horizontal bottom pipe; 154 - 45° bevel pipe section. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the scope of protection of the present application.

[0035] Unless otherwise defined, technical terms or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms "first", "second", and similar terms do not imply any order, quantity, or importance, but are used to identify a distinction between two or more components. The terms "include", "comprise", and the like are used synonymously with the term "comprising" and are intended not to exclude other components or elements. The terms "connected" and "coupled" are not restricted to direct or physical connections or couplings, and can include electrical connections or couplings, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to denote relative positions for ease of description, and can change accordingly when the absolute positions of the described objects change.

[0036] The application provides a natural ventilation direct air cooling exhaust pipe support compensation system. The natural ventilation direct air cooling exhaust pipe is used for connecting a steam turbine exhaust port and an air cooling condenser, and comprises an exhaust main pipe and a plurality of ring-shaped steam distribution pipes connected to the exhaust main pipe. The main pipe segment subsystem comprises a main pipe spring and damper combined support 1, a main pipe guide sliding support 2, a main pipe sliding support 3, a main pipe spring support 4, a large rod compensator, and a hinge type compensator. The main pipe spring and damper combined support 1 is arranged at a position close to the steam turbine exhaust port 10 of the main pipe, and is used for providing elastic support and damping in the vertical direction. The main pipe guide sliding support 2 and the main pipe sliding support 3 are arranged at intervals along the long straight section of the main pipe, and are respectively used for guiding axial sliding and restraining lateral displacement, and providing vertical support. The main pipe spring support 4 is arranged at the connection area of the main pipe and the ring-shaped pipe, and is used for providing elastic support and adjusting local load at the node. The large rod compensator is arranged on the long straight section of the exhaust main pipe, and is used for absorbing axial displacement of the main pipe. The hinge type compensator is arranged in groups at the corners of the main pipe, and is used for absorbing angular thermal displacement of the main pipe. The ring-shaped pipe segment subsystem comprises a ring-shaped pipe guide sliding support arranged corresponding to each ring-shaped steam distribution pipe, and the guide direction of the ring-shaped pipe guide sliding support is set to be radially directed to the geometric center of the ring-shaped pipe. A π-shaped pipe compensation structure is arranged at the end of the last ring-shaped steam distribution pipe. In the connection area of the main pipe and the ring-shaped pipe, the axial thermal expansion generated by the main pipe segment subsystem is accumulated and appears as an axial thrust. The ring-shaped pipe segment subsystem receives the axial thrust through the ring-shaped pipe guide sliding support, and converts the axial thrust into the action of restraining tangential displacement of the ring-shaped pipe and guiding radial expansion of the ring-shaped pipe. The π-shaped pipe compensation structure is used for absorbing the combined displacement accumulated at the end of the ring-shaped pipe in the guiding process.

[0037] The natural ventilation direct air cooling exhaust pipe combined support system provided by the application is an organic whole which is carefully designed based on the thermal expansion displacement law of large exhaust pipe, fluid dynamics characteristics and structural mechanics principles: The mother pipe section is provided with a support structure which is rigid and flexible and has hierarchical vibration reduction: since the mother pipe section is the most heavy and the most intense vibration part of the whole system, the application realizes a unique support structure and a dynamic and static separation vibration control mechanism through the cooperation of the mother pipe spring and damper combined structure 1, the mother pipe guiding sliding support 2, the mother pipe sliding support 3 and the mother pipe spring support 4.

[0038] The traditional pipe support usually only considers static load bearing, while in the application, the spring assembly is used to balance the huge dead weight, realize flexible support and allow the pipe to slowly expand due to heat; meanwhile, the parallel hydraulic dampers are used to be locked instantly in the transient conditions such as start and stop of the turbine, water hammer, strong wind or earthquake, so as to convert the dynamic impact into heat energy dissipation. The characteristics of being soft in static state and rigid in dynamic state cannot be realized by single ordinary rigid support or spring support.

[0039] The mother pipe guiding sliding support 2 strictly limits the transverse displacement of the pipe to prevent instability of the long straight pipe section; while the mother pipe sliding support 3 does not limit the horizontal displacement, effectively releasing the axial cumulative displacement of the pipe due to thermal expansion, and the two adopt a specific interval guiding layout, i.e. four mother pipe guiding sliding supports 2 are arranged along the long straight pipe section of the mother pipe, two mother pipe sliding supports 3 are arranged after the pipe route of the long straight pipe section is deflected, and one mother pipe guiding sliding support 2 is arranged on each side after the three-way branch, in the order of arrangement.

[0040] The application adopts the constant force spring support mode for the mother pipe spring and damper combined support 1 and the mother pipe spring support 4 to solve the problem of excessive vertical thermal displacement of the exhaust pipe, so that the additional force of the exhaust pipe on the turbine exhaust port or the three-way branch remains almost constant (the change rate is less than 5%) when the vertical thermal displacement of the exhaust pipe is tens or even hundreds of millimeters, and the mother pipe guiding support and the mother pipe sliding support form a stable mechanical model, effectively solving the problem of pipe system vibration caused by large vertical thermal displacement of large-diameter thin-wall pipes.

[0041] Meanwhile, the annular pipe section of the application can realize tangential release and multi-stage cooperation. The thermal displacement mode of the annular pipe, i.e. the annular steam distribution pipe, in the application is extremely complex, mainly tangential expansion in the circumferential direction. The application realizes continuous tangential guidance through the cooperation of the first-stage annular pipe guide sliding support 5, the second-stage annular pipe guide sliding support 6, the third-stage annular pipe guide sliding support 7 and the fourth-stage annular pipe guide sliding support 8. The traditional design often sets a fixed support on the annular pipe, resulting in huge torque and shear force. The application discards the fixed point and constructs a guide chain along the steam flow direction. The first-stage annular pipe guide sliding support 5, the second-stage annular pipe guide sliding support 6, the third-stage annular pipe guide sliding support 7 and the fourth-stage annular pipe guide sliding support 8 are distributed along the annular pipe, and the guide groove direction of each support is perpendicular to the tangent direction of the point arc.

[0042] The annular pipe is guided by the above four-stage annular pipe guide sliding supports to expand only in the pipe axis direction, so that the annular pipe of up to hundreds of meters can be uniformly and controllably expanded, avoiding weld cracking caused by local stress concentration and instability overturning caused by uneven expansion of the pipe.

[0043] The connection and cooperation of the mother pipe segment subsystem and the annular pipe segment subsystem in the application realize flexible transition. The application sets the mother pipe guide spring support 4 and the mother pipe guide sliding support 2 in the tee area where the mother pipe enters the annular pipe.

[0044] Among them, the mother pipe spring and damper combined support, the mother pipe guide sliding support and the mother pipe sliding support and the mother pipe spring support in the mother pipe segment subsystem mainly control the axial displacement and vibration, and the annular pipe segment subsystem mainly controls the tangential displacement. The mother pipe spring support is set at the outlet of the tee to convert the huge axial thrust of the mother pipe into the tangential driving force of the annular pipe. It can smoothly convert the one-dimensional (axial) thermal expansion of the mother pipe into the two-dimensional (tangential) thermal expansion of the annular pipe, avoiding interference between the two different displacement modes at the connection, and realizing flexible transition of the entire piping system from straight pipe to ring pipe.

[0045] The system controls the vertical and axial direction through the mother pipe spring and damper combined support 1, controls the lateral direction through the mother pipe guide sliding support 2, and controls the planar tangential direction through the annular pipe guide supports of different stages. The various supports of the application realize protection in the three dimensions of space XYZ. No matter which direction the pipe is subjected to thermal stress, wind load or earthquake force, it can be resolved by a specific support, realizing omnidirectional, multi-angle and three-dimensional flexible protection of large and complex piping systems.

[0046] Please refer to Figure 1 , Figure 1The application of the combined support and thermal displacement compensation system of the application in a typical natural ventilation direct air-cooled exhaust pipe system is shown. The system is drawn from the turbine exhaust port 10, through the exhaust main pipe into the annular pipe, and then gradually divided, through the branch pipe vertical rising section, the horizontal section, and finally into the air-cooled condenser inlet 20.

[0047] The specific implementation and functions of each component are as follows: The main pipe spring and damper combined support 1 of the embodiment is shown in Figure 3 , Figure 4 In this embodiment, it is arranged near the turbine exhaust port 10 as the main support point of the entire pipe system. As shown in Figure 3 and Figure 4 The main pipe spring and damper combined support 1 includes a spring element 102, a damper element 103, a welded pin seat 104, a damper thrust device 105, an A support box support 106, an A main pipe support foundation 107, and an A main pipe support foundation top preset embedded part 108. The support adopts a structure in which two heavy constant force spring elements 102 are connected in parallel with two hydraulic dampers 103, which protects the turbine exhaust port 10. The top of the heavy constant force spring element 102 and the two hydraulic dampers 103 is connected with the support box support 106, and the bottom is connected with the main pipe support foundation 107 through the main pipe support foundation top preset embedded part 108. The support box support 106 is located outside the periphery of the exhaust main pipe.

[0048] The main pipe guide sliding support 2 and the main pipe sliding support 3 of the embodiment are between the compensators of the exhaust main pipe and between the exhaust main pipe and the annular pipe. The main pipe guide sliding support 2 can make the pipeline expand along the predetermined axis, and the main pipe sliding support 3 provides flexible vertical support and allows the pipeline to slide in the horizontal plane. The specific structure of the guide sliding support 2 is shown in Figure 5 , which includes an adjusting steel plate 202, a polytetrafluoroethylene plate 203, a limiting block 204, a support box support 205, a main pipe support foundation 206, and a main pipe support foundation top preset embedded part 207. The specific structure of the main pipe sliding support 3 is shown in Figure 6 , which does not contain the limiting block 204, the main pipe support foundation 206, and the main pipe support foundation top preset embedded part 207 in the middle of the bottom, compared with the main pipe guide sliding support 2.

[0049] As shown in the figure, the bottom of the support box support 205 of the main pipe guide sliding support 2 is provided with symmetrical support columns. A polytetrafluoroethylene (PTFE) plate 203 with a low friction coefficient is placed between the bottom of the support column and the top of the pre-embedded part 207 at the top of the main pipe support foundation. Its design friction coefficient is <0.1. When the main pipe expands due to heat and causes axial displacement, due to the extremely small friction force, the support column of the support box support 205 can generate relative displacement between the top of the PTFE plate 203 and the bottom of the pre-embedded part 207 at the top of the main pipe support foundation and the PTFE plate 203, thereby releasing the thermal expansion force of the pipe and avoiding destructive thrust on the piping system.

[0050] In this embodiment, the limiting block 204 is fixed directly below the bottom of the main pipe, and the bracket box support 205 forms a channel at the corresponding position to cooperate with the limiting block 204. The limiting block 204 is embedded in this channel, and its bottom abuts against the pre-embedded part 207 at the top of the main pipe support foundation 206. The above-mentioned method in this embodiment physically cuts off the path for the pipe to undergo lateral displacement. When the pipe swings laterally due to thermal expansion, wind load, or earthquake, the limiting block 204 will constrain the pipe to move only along the pipe axis direction reserved by the block.

[0051] In this embodiment, the main pipe spring support 4 is located between the exhaust main pipe and the annular pipe. This main pipe spring support 4 is a constant force spring support used to adjust the local load in this area, preventing excessive weight concentration at the tee. The specific details of the main pipe spring support 4 are as follows: Figure 7 As shown, it includes a spring element 402, a limiting block 403, a bracket box support 404, a main pipe support foundation 405, and a pre-embedded part 406 on the top of the main pipe support foundation, as follows. Figure 7 As shown, the top of the spring element 402 is connected to the bottom of the bracket box support 404, and the bottom of the spring element 402 is connected to the mother pipe support foundation 405 through the pre-embedded part 406 at the top of the mother pipe support foundation. At the same time, the limiting block 403 is located at the bottom of the bracket box support 404, and its structural design and sliding principle are the same as the limiting block 204 of the mother pipe guide sliding bracket 2.

[0052] like Figure 1 As shown, in this embodiment, the exhaust header is equipped with three large tie rod compensators 11 and one hinged compensator 12 according to the space and displacement. The large tie rod compensators 11 are used to absorb axial displacement, and the hinged compensator 12 absorbs angular displacement at the bend.

[0053] A π-shaped tube 15 is installed at the end of the fourth-stage annular tube. The structure of the π-shaped tube 15 is as follows: Figure 9As shown, including horizontal top pipe 151, vertical standpipe 152, horizontal bottom pipe 153 and 45° bevel pipe section 154, horizontal top pipe 151, vertical standpipe 152, horizontal bottom pipe 153 are fixedly connected through 45° bevel pipe section 154 to form π-shaped pipe 15 as shown. The π-shaped pipe 15 can simultaneously absorb the axial displacement of its front and rear pipe sections, and has good adaptability to certain lateral displacement. It has high reliability and does not need maintenance, and is particularly suitable for occasions with high long-period operation requirements.

[0054] As shown in the drawings, Figure 2 As shown, two groups of four hinged compensators are arranged in the vertical rising section and the horizontal section of the branch pipe, which are first-stage exhaust branch pipe hinged compensator 13 and second-stage exhaust branch pipe hinged compensator 14, effectively absorbing the lateral displacement and angular displacement of the pipeline.

[0055] As shown in the drawings, Figure 1 As shown in the drawings, the first-stage ring pipe guide sliding support 5, the second-stage ring pipe guide sliding support 6, the third-stage ring pipe guide sliding support 7 and the fourth-stage ring pipe guide sliding support 8 of the embodiment correspond to the multi-stage ring pipe one by one; for the first-stage to the fourth-stage ring pipe, a plurality of ring pipe guide sliding supports are uniformly arranged along the steam flow direction of each stage of ring pipe. The structures of the ring pipe guide sliding supports of each stage are the same, Figure 8 As shown in the drawings, the structure of the ring pipe guide sliding support is shown in the structure diagram, and the sliding direction of the first-stage ring pipe guide sliding support 5 is strictly directed to the center of the air cooling tower (i.e. the center of the ring pipe). When the pipeline is heated and expands radially, it can smoothly slide outward, while the tangential direction is constrained to ensure the stability of the ring structure. As shown in the drawings, Figure 8 As shown in the drawings, the first-stage ring pipe guide sliding support includes ring pipe adjusting steel plate 502, ring pipe PTFE plate 503, ring pipe limiting block 504, ring pipe support box type support 505, ring pipe support foundation 506 and ring pipe support foundation top pre-set embedded part 507; similar to the structure design of the mother pipe guide sliding support 2, the ring pipe PTFE plate 503 is located between the bottom of the ring pipe support box type support 505 support column and the ring pipe support foundation top pre-set embedded part 507, used to reduce the friction force, so that the pipeline overcomes the friction resistance, thereby releasing the thermal expansion force of the pipeline, avoiding destructive thrust on the piping system; similarly, the ring pipe limiting block 504 is fixedly connected with the corresponding ring pipe section, and the channel designed on the ring pipe support box type support 505 cooperates with the ring pipe limiting block 504 to constrain the sliding path of the ring pipe limiting block 504, so as to cut off the path of displacement in other directions of the pipeline.

[0056] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A support and compensation system for a natural ventilation direct air-cooled exhaust duct, wherein the natural ventilation direct air-cooled exhaust duct is used to connect the exhaust port of a steam turbine to an air-cooled condenser, and includes a main pipe and a multi-stage annular pipe connected thereto, characterized in that, include: The main pipe subsystem includes: a main pipe spring and damper combined support, a main pipe guide sliding support, a main pipe sliding support, a main pipe spring support, a large tie rod compensator, and a hinged compensator. The main pipe spring and damper combined support is located on the main pipe near the turbine exhaust port to provide vertical elastic support and horizontal damping. The main pipe guide sliding support and the main pipe sliding support are arranged at intervals along the long straight section of the main pipe to guide axial sliding and constrain lateral displacement, and to provide vertical support, respectively. The main pipe spring support is located in the connection area between the main pipe and the annular pipe to provide elastic support and adjust local loads at this node. The large tie rod compensator is located on the long straight section of the exhaust main pipe to absorb the axial displacement of the main pipe. The hinged compensators are arranged in groups at the corners of the main pipe to absorb the angular thermal displacement of the main pipe. The annular pipe segment subsystem includes an annular pipe guide sliding support corresponding to each stage of the annular steam distribution pipe, the guiding direction of which is set radially toward the geometric center of the annular pipe of that stage; a π-shaped pipe compensation structure is provided at the end of the last stage of the annular steam distribution pipe. In the connection area between the main pipe and the annular pipe, the axial thermal expansion generated by the main pipe segment subsystem is accumulated and manifested as an axial thrust; the annular pipe segment subsystem, through its annular pipe guide sliding support, receives this axial thrust and converts it into a function that constrains the tangential displacement of the annular pipe and guides its radial expansion; the π-shaped pipe compensation structure is used to absorb the composite displacement accumulated at the end of the annular pipe during this guiding process.

2. The natural ventilation direct air-cooled exhaust duct support and compensation system as described in claim 1, characterized in that, The main tube spring bracket is located directly below the tee structure connecting the main tube and the first-stage annular tube; the first annular tube guide sliding bracket of the first-stage annular tube is installed close to the interface of the tee structure on the annular tube, and its preset annular tube guide direction is perpendicular to the axial center line of the main tube at the interface in the horizontal plane.

3. The natural ventilation direct air-cooled exhaust duct support and compensation system as described in claim 1, characterized in that, The main tube spring and damper combined support includes: a support box support, at least one spring assembly and at least one damper; one end of each of the spring assembly and the damper is connected to the bottom of the support box support, and the other end of each is connected to the support foundation through a pre-embedded part at the top of the support foundation; wherein, the spring assembly bears the vertical load of the main tube at the location, the damper bears the horizontal load of the main tube at the location, and the main tube is located inside the support box support.

4. The natural ventilation direct air-cooled exhaust duct support and compensation system as described in claim 3, characterized in that, The main pipe guide sliding support also includes a support box support and a support foundation; an adjusting steel plate is connected to the support foundation of the main pipe guide sliding support through embedded parts, and a polytetrafluoroethylene plate is provided between the support column of the support box support and the adjusting steel plate; the main pipe guide sliding support also includes a limiting structure, which is used to constrain the axial displacement of the pipeline.

5. The natural ventilation direct air-cooled exhaust duct support and compensation system as described in claim 1, characterized in that, The π-shaped pipe compensation structure includes a horizontal jacking pipe, two vertical risers and a horizontal bottom pipe, wherein the connection between the vertical risers and the horizontal jacking pipe and the horizontal bottom pipe is a 45° oblique cut pipe section.

6. The natural ventilation direct air-cooled exhaust duct support and compensation system as described in claim 1, characterized in that, Polytetrafluoroethylene (PTFE) sheets are laid between the sliding surfaces of the main tube sliding support and the annular tube guide sliding support.

7. The natural ventilation direct air-cooled exhaust duct support and compensation system as described in claim 1, characterized in that, It also includes hinged compensators installed on the vertical and horizontal sections of the exhaust branch pipe.

8. A method for using a natural ventilation direct air-cooled exhaust duct support and compensation system as described in any one of claims 1-7, characterized in that, include: A combination bracket of a main pipe spring and a damper is installed near the turbine exhaust port of the main pipe to provide vertical elastic support and suppress transient vibrations. Along the long straight section of the main pipe, guide sliding supports and sliding supports of the main pipe are arranged at intervals to guide axial sliding and constrain lateral displacement; and large tie rod compensators are installed on the long straight section, and hinged compensators are installed in groups at the bends to absorb axial and angular thermal displacement respectively. Multiple annular pipe guide sliding supports are set for each stage of annular steam distribution pipe, and their sliding direction is set to radially point towards the geometric center of the annular pipe of that stage; and a π-shaped pipe compensation structure is set at the end of the last stage of annular steam distribution pipe. A spring support for the main pipe is provided in the connection area between the main pipe and the annular pipe. This allows the axial thermal displacement of the main pipe section to be converted into a force that drives and guides the radial expansion of the annular pipe, while the displacement at the end of the annular pipe is absorbed by the π-shaped pipe compensation structure.

9. The method for supporting and compensating natural ventilation direct air-cooled exhaust ducts as described in claim 8, characterized in that, In the main pipe section, the combination of the main pipe spring and damper support achieves flexible support under static load and rigid locking under dynamic load; the large tie rod compensator absorbs axial displacement, and the group of hinge-type compensators absorbs angular displacement; the spaced arrangement of the main pipe guide sliding support and the main pipe sliding support achieves orderly release of axial displacement and maintenance of lateral stability; in the annular pipe section, when the pipe is heated, the annular pipe guide sliding support constrains displacement and guides the annular pipe to expand in a preset radial direction; the π-shaped pipe compensation structure absorbs the combined axial, lateral, and angular displacements accumulated at the end of the annular pipe due to this radial expansion.

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