An assembled concrete cooling pipe structure and method for gravity dam construction

Abstract

The application belongs to the technical field of gravity dam construction, and proposes an assembled concrete cooling pipe structure and method for gravity dam construction. The cooling pipe is composed of a plurality of series-connected pipe body units, and a metal pipe of the pipe body unit is provided with an inner lining piece; the inner lining piece forms a longitudinal and transverse interlaced cage structure through a strip-shaped plate and an elastic steel sheet, the strip-shaped plate is provided with a rough surface and a notch, the steel sheet can be stretched and contracted to realize diameter adjustment, and can forcibly generate turbulent flow to destroy the laminar flow bottom layer. The method includes raw material pretreatment, notch and rough surface processing, inner lining piece assembly, metal pipe assembly and fixation, and pipe body unit series connection. The application has stable structure, convenient manufacturing, can reduce the boundary layer thermal resistance, improve the heat transfer efficiency, reduce the concrete temperature cracks, and is suitable for the construction requirements of gravity dam.

Description

Technical Field

[0001] This invention belongs to the field of gravity dam construction technology, specifically an assembled concrete cooling pipe structure and method for gravity dam construction. Background Technology

[0002] In the construction of large-volume concrete structures such as gravity dams, cooling water needs to be introduced through cooling pipes. The heat of hydration is carried away by the heat exchange between the water flow inside the pipe and the concrete outside the pipe, thereby effectively controlling the internal temperature gradient of the concrete. The core objective of this technology is to improve the heat dissipation efficiency of the water flow. However, traditional cooling pipes mostly use steel pipes with smooth inner walls. The boundary layer thermal resistance caused by the laminar flow layer (also known as the "dead water film") has become a major bottleneck restricting the heat transfer efficiency.

[0003] Heat transfer requires a complete path: first, it is conducted from the interior of the concrete to the outer wall of the steel pipe; then, it passes through the boundary layer thermal resistance region on the inner wall of the pipe, where heat transfer relies solely on molecular conduction (the heat transfer efficiency in this region is far lower than the convective heat transfer of the main water flow); finally, it enters the core water flow region and is carried away. Crucially, this boundary layer thermal resistance accounts for 60% to 80% of the total heat transfer resistance, effectively creating an additional thermal barrier in the heat transfer path, significantly reducing the cooling efficiency of the cooling pipe.

[0004] Poor heat dissipation efficiency can lead to the inability to dissipate the heat of hydration inside the concrete in a timely manner, resulting in a temperature control lag phenomenon of "rapid heating and slow cooling", which can easily induce temperature cracks in the concrete. Ultimately, this will weaken the load-bearing capacity, impermeability and durability of the dam structure, becoming a key challenge in the quality control of large-volume concrete projects.

[0005] More importantly, even if the water flow rate is increased by increasing the power of the water pump, the "dead water film" can only be slightly thinned. It cannot effectively impact the film layer, and the effect of improving heat dissipation efficiency is very limited. It will still cause the temperature difference between the inside and outside of the concrete to exceed the standard, and eventually lead to temperature cracks.

[0006] Clearly, simply increasing flow rate and increasing pipe density cannot completely solve the above problems; only by upgrading the technology at the level of structural design that disrupts the laminar flow layer can the boundary layer thermal resistance be fundamentally reduced, the heat transfer efficiency improved, and the temperature control requirements of large-volume concrete be met.

[0007] To disrupt the laminar sublayer, the applicant previously proposed a combined cooling water pipe solution using steel pipes and spring hoses, and applied for an invention patent for this (application number: 202511525394.7). However, experimental studies have shown that while this solution can disrupt the laminar sublayer, it still has some drawbacks: First, the manufacturing process is cumbersome, and the precision of key processes such as airbag inflation pressure control and glue injection volume control is difficult to control precisely, which can easily lead to quality defects such as localized voids and hose deformation; second, the performance of the glue is easily affected by environmental factors, and it is prone to aging and hydrolysis failure during long-term use; third, the thermal expansion coefficients of the steel pipe and the spring hose are significantly different, and stress concentration is easily generated at the interface during the heating and cooling cycle of concrete temperature control. Under long-term cyclic action, the glue bonding layer is prone to cracking, thereby destroying the integrity of the turbulence structure.

[0008] Based on the shortcomings of the above-mentioned solutions, the existing technical solutions need to be further upgraded and improved to enhance the structural stability, ease of manufacture, and engineering applicability of the cooling water pipes. Summary of the Invention

[0009] Based on the problems existing in the background technology, the present invention proposes an assembled concrete cooling pipe structure and process for gravity dam construction.

[0010] Firstly, this technical solution proposes an assembled concrete cooling pipe structure for gravity dam construction, comprising several pipe units connected in series. Each pipe unit includes a metal pipe, and an inner liner connected to the inner wall of the metal pipe is fitted inside the metal pipe to create an uneven structure on the inner wall of the metal pipe, thereby generating turbulence in the water flow inside the pipe.

[0011] The inner lining includes several strip plates, which are arranged circumferentially and axially along the inner wall of the metal tube to form axial vertical ribs;

[0012] The strip plates are connected in series by several elastic and bendable steel sheets; several spaced hoops are fitted on the strip plates, and a clamp is connected to one side of the hoops. The clamp has a through hole, and the steel sheets pass through the through holes on adjacent hoops to form a ring-like series connection.

[0013] The steel sheets are arranged in a circular shape, forming annular transverse ribs inside the strip plate, which together with the strip plate constitute a crisscrossing cage structure; the front and rear ends of the steel sheets can be adjusted relative to each other to achieve variable diameter adjustment of the cage structure.

[0014] Preferably, the surface of the strip away from the inner wall of the metal tube is referred to as the first surface, and the first surface has a textured structure, which is a hole array or a convex dot array.

[0015] Preferably, the steel sheet is spring steel.

[0016] Preferably, the length of the strip is less than or equal to the length of the metal tube.

[0017] Preferably, the strip plate has several spaced slots along its length on the surface near the inner wall of the metal tube, and the clamp can be engaged at the slots.

[0018] Preferably, adjacent pipe units are connected by welding, flanges, or pipe sections.

[0019] Preferably, the clamp is made of metal, engineering plastic, or composite material.

[0020] Secondly, this technical solution also proposes a method for manufacturing an assembled concrete cooling pipe structure for gravity dam construction, comprising the following methods:

[0021] S1, Raw material pretreatment:

[0022] Select metal pipes and strip plates as substrates according to project requirements, and cut them to the designed length;

[0023] S2, Create the grooves and rough edges:

[0024] Along the length of the strip, grooves are machined at the designed positions, ensuring that the groove positions of adjacent strips correspond; a rough surface structure is constructed on the first surface of the strip to ensure that the first surface is uneven;

[0025] S3, Inner Liner Assembly:

[0026] Implement using either of the following two methods:

[0027] The first type:

[0028] First, place the clamp on the strip plate and slide it along the strip plate to adjust its position so that it fits into the groove. Then, select the clamps of the same height and pass the steel sheets through the through holes of the corresponding clamps of all the strip plates in sequence to form a ring series. Adjust the position of the strip plates so that the strip plates are evenly distributed around the circumference to form a circular cage structure that matches the inner diameter of the metal pipe.

[0029] The second type:

[0030] ① Assemble the hoop and steel sheet: Pass the steel sheet through the through hole on the hoop, and pass the number of hoops corresponding to the strip plate through each steel sheet to form a "steel sheet-hoop" assembly;

[0031] ② Positioning and fixing of strip plates: Place the strip plates vertically on the indexing frame, with the strip plates evenly distributed along the circumference of the indexing frame;

[0032] ③ Assembly of hoop and strip plate: Take one set of pre-assembled "steel sheet-hoop" components and align each hoop with the corresponding strip plate; put the hoop on the corresponding strip plate and slide the hoop along the strip plate to adjust its position so that it is engaged in the slot;

[0033] Repeat the above operation until all "steel sheet-hoop" components are assembled with the strip plates to form a preliminary cage structure;

[0034] ④ Disassembling the inner lining: Hold the indexing frame, lift the assembled inner lining, and slowly remove it;

[0035] S4, The inner liner is assembled and fixed to the metal tube:

[0036] Press the circular cage structure to reduce its diameter to less than the inner diameter of the metal tube. The steel sheet is pressed and generates elastic force, pushing the circular cage structure from one end of the metal tube into the designed position.

[0037] Release the pressure, and the steel sheet will naturally expand under the action of elasticity until the second surface of the strip plate is tightly attached to the inner wall of the metal tube, achieving initial positioning;

[0038] By using a two-end welding method, the two ends of the strip plate are welded and fixed to the inner wall of the metal pipe to complete the assembly of a single pipe unit;

[0039] Repeat the above steps to complete the processing and assembly of multiple single-section tube units;

[0040] S5, tube units connected in series:

[0041] Based on the cooling path design of the gravity dam casting blocks, several single pipe units are connected in series by welding or flanges to form an integral pipeline.

[0042] Preferably, the indexing frame in S3 includes a ring, and a base is provided below the ring. The base and the ring are fixedly connected by a connecting rod. A plurality of limiting ribs are connected to the inner wall of the ring in the circumferential direction, and a limiting slot is formed between the limiting ribs and the inner wall of the ring. The bottom end of the strip plate can be adapted to be inserted into the limiting slot. A set screw is threaded on the limiting rib.

[0043] Preferably, the specific method of using the indexing frame is as follows:

[0044] a. Positioning and fixing of the strip plate:

[0045] Insert the strip plate into each limiting slot, so that the bottom end of the strip plate passes through the limiting slot and is pressed against the upper surface of the base; then screw the set screws inward one by one until the set screws are pressed against the side wall of the strip plate, forcing the strip plate to fit against the inner wall of the ring, thus completing the positioning and fixing of the strip plate on the indexing frame.

[0046] b. Removal of inner lining components:

[0047] When the inner liner needs to be removed, first loosen all the set screws outward, then hold the main body of the inner liner and lift it vertically and steadily upward until the strip plate is completely disengaged from the limit slot, thus completing the overall disassembly.

[0048] The above technical solution has the following advantages:

[0049] 1. This invention, by setting an inner lining inside a metal pipe, the inner lining being a cage-like structure formed by strip plates and steel sheets, can create an uneven structure inside the metal pipe, forming an axial and radial three-dimensional turbulence system, forcing water flow disturbance to generate turbulence, which can destroy the laminar flow layer, shorten the heat transfer path from the pipe wall to the water core, reduce boundary layer thermal resistance, improve heat transfer efficiency, solve the problem of temperature control lag in concrete with rapid heating and slow cooling, and reduce the risk of temperature cracks.

[0050] 2. In this invention, the inner liner can be adjusted by extending and retracting the steel sheet at both ends. When pressed, the diameter decreases, making it easy to push into the metal tube. After releasing the pressure, the steel sheet elastically returns to its original position, allowing the strip plate to fit tightly against the inner wall of the metal tube. This diameter adjustment method eliminates the need for complex assembly tools during assembly, reducing assembly difficulty and improving construction efficiency.

[0051] 3. By setting an indexing frame, this invention can accurately position the strip plate, ensuring that the cage structure is compatible with the metal tube; it can save labor, improve assembly efficiency, and avoid deformation of the inner lining; it is simple and easy to operate, and can also ensure the consistency of batch assembly. Attached Figure Description

[0052] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below.

[0053] Figure 1 This is a schematic diagram of the structure after multiple tubular units are connected in series.

[0054] Figure 2 It is a three-dimensional view of a single tube unit.

[0055] Figure 3 yes Figure 2 Three-dimensional inner lining Figure 1 .

[0056] Figure 4 yes Figure 2 Three-dimensional inner lining Figure 2 .

[0057] Figure 5 It is a three-dimensional diagram of the clamp.

[0058] Figure 6 It is a three-dimensional single strip plate Figure 1 .

[0059] Figure 7 It is a three-dimensional single strip plate Figure 2 .

[0060] Figure 8 This is a three-dimensional diagram of the indexing frame.

[0061] Figure 9 It is a three-dimensional structure when the inner lining is used in conjunction with the indexing frame. Figure 1 .

[0062] Figure 10 It is a three-dimensional structure when the inner lining is used in conjunction with the indexing frame. Figure 2 .

[0063] Explanation of reference numerals in the attached figures:

[0064] 1. Metal pipe; 2. Inner lining; 21. Strip plate; 211. Groove; 212. First surface; 22. Steel sheet; 23. Hoop; 231. Guide hole; 232. Jacket; 233. Through hole;

[0065] 3. Indexing frame; 31. Base; 311. Anchor hole; 32. Ring; 33. Connecting rod; 34. Limiting rib; 341. Screw hole. Detailed Implementation

[0066] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0067] like Figure 1 - Figure 10 As shown, this embodiment proposes an assembled concrete cooling pipe structure for gravity dam construction, comprising several pipe units connected in series, such as... Figure 1 As shown, multiple tube units are connected in series to form a cooling pipe; the specific structural form of the tube unit is as follows:

[0068] The pipe unit includes a metal pipe 1, and an inner liner 2 connected to the inner wall of the metal pipe 1 is installed inside the metal pipe 1 to create an uneven structure on the inner wall of the metal pipe 1, so that the water flow inside the pipe will generate turbulence. The material of the metal pipe 1 includes, but is not limited to, low carbon steel, stainless steel, galvanized steel and other metal materials, which can not only ensure the pressure bearing capacity of the pipeline for cooling water, but also adapt to the complex construction conditions in the process of gravity dam concrete pouring.

[0069] The inner liner 2 includes several strip plates 21, which are arranged circumferentially and axially along the inner wall of the metal pipe 1 to form axial vertical ribs. The strip plates 21 are evenly distributed circumferentially along the metal pipe 1 at equal intervals, for example, 6-8 plates, the specific number of which can be adjusted according to the inner diameter of the metal pipe 1. The material of the strip plates 21 is consistent with that of the metal pipe 1, and the thickness can be designed to be 2-5mm, balancing structural strength and water flow area. The width is determined based on the principle of forming effective convex turbulence without excessively reducing the water flow cross-section; for example, it can be 1 / 10-1 / 8 of the inner diameter of the metal pipe 1. The main function of the inner liner 2 is to construct a three-dimensional uneven structure with both axial extension and radial protrusions on the originally smooth surface of the inner wall of the metal pipe 1.

[0070] The strip plates 21 are connected in series by several elastic and bendable steel sheets 22; several spaced hoops 23 are fitted on the strip plates 21, and a clamp 232 is connected to one side of the hoops 23. The clamp 232 has a through hole 233. The steel sheets 22 pass through the through holes 233 on the adjacent hoops 23 to form a ring-shaped series; the steel sheets 22 are enclosed in a circle from head to tail to form a ring-shaped transverse rib inside the strip plates 21, which together with the strip plates 21 form a crisscross cage structure; the head and tail ends of the steel sheets 22 can be relatively stretched and adjusted to realize the diameter adjustment of the cage structure.

[0071] In some feasible embodiments, the steel sheet 22 is made of spring steel with a thickness of 0.8–1.5 mm, possessing the characteristics of being able to bend and shrink under pressure and elastically return to its original position after pressure relief. Its length needs to match the inner diameter of the metal tube 1. In some embodiments, when the inner diameter of the metal tube 1 is large, an overlap adjustment section of 5–20 mm can be reserved at both ends of the steel sheet 22, and the overlapped part can slide relative to each other. In other embodiments, when the inner diameter of the metal tube 1 is small, a gap setting can be adopted, and the gap width can be 3–8 mm. In this case, when the steel sheet 22 shrinks, the two ends move away from each other, and the gap increases; when it expands, the two ends move closer together, and the gap decreases.

[0072] Regarding the specific structural form of the clamp 23, the following structure can be adopted:

[0073] The hoop 23 has an overall U-shaped structure with a guide hole 231 in the middle. The strip plate 21 passes through the guide hole 231 to achieve the sleeve connection between the hoop 23 and the strip plate 21. The hoop 23 and the clamp 232 can be integrally molded. The clamp 232 has a narrow slit, which is the through hole 233. The guide hole 231 is a vertical structure, and the through hole 233 is a horizontal structure. The two are set perpendicularly.

[0074] The principle of improved heat exchange efficiency: After the strip plate 21 and the steel sheet 22 are connected to each other, they form a cage structure that matches the inner wall contour of the metal pipe 1. This structure creates three-dimensional turbulence. Specifically, the strip plate 21 guides the water flow to generate branched turbulence along the axial direction, while the steel sheet 22 blocks the water flow in a plane perpendicular to the axis, forcing the water flow to flow around, collide, and form vortices. The superposition of the two turbulence methods can transform the laminar flow state of the water flow into a strong turbulent flow state, significantly shortening the path of heat transfer from the pipe wall to the core of the water flow, reducing the boundary layer thermal resistance, improving heat transfer efficiency, solving the problem of temperature control lag in concrete that heats up quickly and cools down slowly, and reducing the risk of temperature cracks.

[0075] In some embodiments, the surface of the strip plate 21 away from the inner wall of the metal tube 1 is designated as the first surface 212, and the first surface 212 has a textured structure, which is a perforated array or a dotted array. By constructing an uneven textured surface on the first surface 212, the local laminar flow layer formed by the water flow on the surface of the strip plate 21 can be further broken, enhancing the intensity of water flow disturbance. The perforated array can be through holes or blind holes, and the dotted array is preferably hemispherical or frustum-shaped. The perforated array or dotted array can be processed by CNC drilling or stamping, with easily controllable precision, and can be mass-produced.

[0076] In some embodiments, the length of the strip plate 21 is less than or equal to the length of the metal pipe 1, which ensures that the inner liner 2, after being assembled into a cage structure, can be completely contained inside the metal pipe 1, and prevents the end of the strip plate 21 from extending beyond the port of the metal pipe 1, thus affecting the overall installation of the cooling water pipe.

[0077] In some embodiments, the strip plate 21 has a plurality of spaced slots 211 along its length on the surface near the inner wall of the metal tube 1, and the clamp 23 can be engaged at the slots 211.

[0078] On the one hand, the slot 211 provides a predetermined position for the clamp 23. When the strip plate 21 equipped with the clamp 23 is placed into the metal pipe 1, the strip plate 21 fits tightly against the inner wall of the metal pipe 1. The clamping effect is formed by the cooperation between the slot 211 and the pipe wall, which effectively prevents the clamp 23 from shifting under the impact of water flow.

[0079] On the other hand, the slot 211 can serve as a guide reference when the sleeve 23 is fitted. Even if the diameter of the sleeve 23 is appropriately increased, the sleeve can still be fitted by means of the positioning function of the slot 211. There is no need to strictly control the size matching accuracy between the sleeve 23 and the strip plate 21. This reduces the processing difficulty of the sleeve 23 and reduces the alignment operation cost during assembly, significantly improving the convenience and efficiency of assembly.

[0080] In some embodiments, the sleeve 23 is made of metal, engineering plastic, or composite material. Metal materials may include stainless steel, galvanized steel, etc.; engineering plastics may include polypropylene, ABS, etc.; and composite materials may include glass fiber reinforced epoxy resin, carbon fiber modified resin, etc. In this embodiment, the sleeve 23 is preferably made of metal, which has stable mechanical properties and a coefficient of thermal expansion close to that of the metal tube 1 and the strip plate 21. Thus, both the inner liner 2 and the outer metal tube 1 of this invention are made of metal, resulting in a closer coefficient of thermal expansion. Furthermore, the absence of an adhesive bonding layer and the lack of adhesive aging lead to better structural stability and durability, preventing cracking due to temperature cycling and effectively improving the long-term structural stability and service life of the cooling pipe.

[0081] In some embodiments, adjacent pipe units are connected by welding, flanges, or pipe sections, which can be flexibly selected according to the needs of gravity dam concrete construction.

[0082] Compared to the previous glue and airbag solutions, the cooling pipe structure proposed in this embodiment abandons the airbag and glue system and adopts a process of connecting and welding 22 steel sheets in series. This simplifies the process and eliminates the need for high-precision glue injection or airbag pressure adjustment, making it easier to control precision and reducing quality defects such as hollow glue and deformation. The ease of manufacturing and quality stability are greatly improved.

[0083] This embodiment also proposes a method for manufacturing an assembled concrete cooling pipe structure for gravity dam construction, as follows:

[0084] S1, Raw material pretreatment:

[0085] Select metal pipe 1 and strip plate 21 as base materials according to project requirements, and cut them to the designed length; select metal pipe 1 and strip plate 21 as base materials according to project requirements, and cut them to the designed length; use sandpaper or a rust remover to remove rust and oil stains from the inner wall of metal pipe 1 and the surface of strip plate 21.

[0086] S2, create groove 211 and rough surface:

[0087] Along the length of the strip plate 21, a groove 211 is machined at the designed position, and the positions of the grooves 211 of adjacent strip plates 21 are ensured to correspond; a rough surface structure is constructed on the first surface 212 of the strip plate 21 to ensure that the first surface 212 is uneven;

[0088] S3, Inner Liner 2 Assembly:

[0089] The assembly of the inner liner 2 can be achieved using either of the following two methods:

[0090] The first type:

[0091] First, the clamp 23 is fitted onto the strip plate 21 and slid along the strip plate 21 to adjust its position so that it is engaged in the slot 211; the slot 211 is used to position and pre-fix the clamp 23; then, the clamps 232 of the same height are selected, and the steel sheet 22 is passed through the through holes 233 of the corresponding clamps 232 of all strip plates 21 in sequence to form a ring series; specifically, the steel sheet 22 is inserted from the through hole 233 of the clamp 232 of the first strip plate 21 corresponding to the clamps 232 of the same height on all strip plates 21, and then passes through the through holes 233 of the corresponding clamps 232 of the remaining strip plates 21 in sequence, so that the steel sheet 22 is connected end to end to realize the ring series of all strip plates 21;

[0092] Adjust the position of the strip plate 21 so that the strip plate 21 is evenly distributed around the circumference, forming a circular cage structure that matches the inner diameter of the metal tube 1; this lays the foundation for subsequent assembly with the metal tube 1.

[0093] The second type:

[0094] ① Assemble the hoop 23 and steel sheet 22: Pass the steel sheet 22 through the through hole 233 on the hoop 23. Each steel sheet 22 is fitted with a number of hoop 23 corresponding to the number of strip plates 21 (if 6 strip plates 21 are to be distributed circumferentially later, then 6 hoop 23 are to be fitted on a single steel sheet 22), forming a "steel sheet 22-hoop 23" assembly. When assembling, it is necessary to leave a certain adjustment margin at the beginning and end of the steel sheet 22 to reserve space for the subsequent diameter change of the cage structure.

[0095] ② Positioning and fixing of strip plate 21: Place strip plate 21 vertically on indexing frame 3, with strip plate 21 evenly distributed around the circumference of indexing frame 3.

[0096] ③ Assembly of hoop 23 and strip plate 21: Take one set of pre-assembled "steel sheet 22-hoop 23" components and align each hoop 23 with the corresponding strip plate 21; put the hoop 23 onto the corresponding strip plate 21, slide the hoop 23 along the strip plate 21 to adjust its position, so that it is locked into the slot 211, and confirm that the connection between the hoop 23 and the strip plate 21 is stable.

[0097] Repeat the above operation until all "steel sheet 22-hoop 23" components are assembled with strip plate 21 to form a preliminary cage structure.

[0098] ④ Remove inner liner 2: Hold the indexing frame 3, lift the assembled inner liner 2, and slowly remove it.

[0099] The specific structural form of indexing frame 3 in S3:

[0100] It includes a circular ring 32, with a base 31 below the circular ring 32. The base 31 and the circular ring 32 are fixedly connected by connecting rods 33, and the number of connecting rods 33 can be set to 3-4. The shape of the base 31 can be circular or square. The base 31 can be pre-drilled with anchor holes 311 to facilitate fixing on the construction platform and prevent displacement during operation. The inner wall of the circular ring 32 is connected with several limiting ribs 34 along the circumference. The number of limiting ribs 34 is consistent with the number of strip plates 21 to be assembled, such as 6 strip plates 21 corresponding to 6 limiting ribs 34. A limiting slot is formed between the limiting ribs 34 and the inner wall of the circular ring 32. The limiting slot is "U" shaped, and its width is adapted to the thickness of the strip plate 21. The bottom end of the strip plate 21 can be inserted into the limiting slot.

[0101] The limiting rib 34 is threaded with a set screw (not shown in the figure). Specifically, each limiting rib 34 has a screw hole 341 in the middle, and a set screw is adapted to be connected in the screw hole 341. The set screw is a high-strength bolt, and a rubber pad can be added to the end to avoid scratching the surface of the strip plate 21 when tightening. The set screw can be screwed in or out along the axial direction of the screw hole 341 for lateral fixation of the strip plate 21.

[0102] The specific usage method of indexing frame 3 is as follows:

[0103] a. Positioning and fixing of strip plate 21:

[0104] Insert the strip plate 21 vertically into each limiting slot, so that the bottom end of the strip plate 21 passes through the limiting slot and is pressed against the upper surface of the base 31. Then, starting from any limiting rib 34, screw the set screw inward one by one until the set screw is pressed against the side wall of the strip plate 21, forcing the strip plate 21 to fit against the inner wall of the ring 32, thus completing the positioning and fixing of the strip plate 21 on the indexing frame 3. At this time, the strip plate 21 is constrained by the vertical limiting of the slot and the lateral fixing of the set screw, achieving circumferential uniform distribution and axial stable positioning, avoiding displacement during subsequent assembly.

[0105] b. Removal of inner liner 2:

[0106] When the inner liner 2 needs to be removed, first loosen all the set screws outward, hold the ring 32 or connecting rod 33 of the indexing frame 3 with one hand, and hold the main body of the inner liner 2 with the other hand, and lift it vertically and steadily until the strip plate 21 is completely disengaged from the limiting slot, thus completing the overall disassembly.

[0107] S4, Inner liner 2 is assembled and fixed to metal tube 1:

[0108] Press the circular cage structure to reduce its diameter to less than the inner diameter of the metal tube 1. At this time, the steel sheet 22 undergoes elastic deformation due to the pressure and stores the restoring force, pushing the circular cage structure from one end of the metal tube 1 into the designed position.

[0109] When the pressure is released, the steel sheet 22 expands naturally under the action of elasticity, pushing the strip plate 21 to fit against the inner wall of the metal tube 1 until the second surface of the strip plate 21 fits tightly against the inner wall of the metal tube 1, achieving initial positioning and preventing displacement during subsequent welding.

[0110] By using a two-end welding method, the two ends of the strip plate 21 are welded and fixed to the inner wall of the metal pipe 1 to complete the assembly of a single pipe unit;

[0111] Repeat the above steps to complete the processing and assembly of multiple single-section pipe units; after each section is processed, a water pressure test must be performed to check for leaks in the welds and bonding surfaces.

[0112] S5, tube units connected in series:

[0113] Based on the cooling path design of the gravity dam casting blocks, several individual pipe units are connected in series by welding or flanges to form a complete pipeline. Pipe supports are pre-installed within the casting chamber, and individual cooling water pipes are arranged at designed intervals. These individual cooling water pipes are then connected in series by welding or flanges to form a complete pipeline. After the series connection is completed, a leak test is performed on the entire pipeline to ensure there are no leaks at the welds or flange connections.

[0114] Application results:

[0115] The indexing frame 3 is mainly used to form standardized positioning. The equally spaced limiting ribs 34 set along the circumference of the inner wall of the ring 32 directly define the uniform circumferential distribution points for the strip plate 21, avoiding the problem of uneven spacing caused by manual placement based on experience. With the lateral fixing of the top screws on the limiting ribs 34, the strip plate 21 can be forced to fit tightly against the inner wall of the ring 32 to avoid displacement and ensure that the final assembled cage structure is a regular circle.

[0116] Indexing frame 3 replaces manual support with automatic constraint, enabling single-person operation without the need for multiple people to collaborate, freeing up manpower, reducing positioning costs, and significantly improving the assembly efficiency of inner liner 2.

[0117] The indexing frame 3 has a simple overall structure and is easy to manufacture. It does not require complicated debugging or professional tools, and workers can get started after simple training, thus reducing the operating threshold.

[0118] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing an assembled concrete cooling pipe structure for gravity dam construction, wherein, The assembled concrete cooling pipe structure used for gravity dam construction includes several pipe units connected in series. Each pipe unit includes a metal pipe (1). The metal pipe (1) is fitted with an inner liner (2) connected to the inner wall of the metal pipe (1) to create an uneven structure on the inner wall of the metal pipe (1) so that the water flow inside the pipe will generate turbulence. The inner lining (2) includes several strip plates (21), which are arranged circumferentially and axially along the inner wall of the metal tube (1) to form axial vertical ribs; The strip plates (21) are connected in series by a number of elastic and bendable steel sheets (22); a number of spaced hoops (23) are fitted on the strip plates (21), and a sleeve (232) is connected to one side of the hoops (23). The sleeve (232) has a through hole (233), and the steel sheets (22) pass through the through holes (233) on the adjacent hoops (23) to form a ring series; The steel sheet (22) is enclosed in a circle at both ends, forming an annular transverse rib inside the strip plate (21), which together with the strip plate (21) constitutes a crisscrossing cage structure; the front and rear ends of the steel sheet (22) can be relatively stretched and adjusted to realize the variable diameter adjustment of the cage structure. The surface of the strip plate (21) away from the inner wall of the metal tube (1) is called the first surface (212), and the first surface (212) has a textured structure, which is a hole array or a convex dot array; The strip plate (21) has several spaced slots (211) along its length on the surface near the inner wall of the metal tube (1), and the clamp (23) can be locked in the slots (211); The method of manufacturing is characterized by comprising: S1, Raw material pretreatment: According to the project requirements, metal tubes (1) and strip plates (21) are selected as the base materials and cut to the designed length; S2, create the groove (211) and the rough surface: Along the length of the strip plate (21), a groove (211) is machined at the designed position, and the grooves (211) of adjacent strip plates (21) are aligned; a rough surface structure is constructed on the first surface (212) of the strip plate (21) to ensure that the first surface (212) is uneven; S3, Inner Liner (2) Assembly: ① Assemble the hoop (23) and the steel sheet (22): Pass the steel sheet (22) through the through hole (233) on the hoop (23), and pass the number of hoops (23) corresponding to the strip plate (21) through each steel sheet (22) to form a "steel sheet (22) - hoop (23)" assembly; ② Positioning and fixing of strip plate (21): The strip plate (21) is placed vertically on the indexing frame (3), and the strip plate (21) is evenly distributed along the circumference of the indexing frame (3); the indexing frame (3) includes a ring (32), and a base (31) is provided below the ring (32). The base (31) and the ring (32) are fixedly connected by a connecting rod (33); a number of limiting ribs (34) are connected along the circumference of the inner wall of the ring (32), and a limiting slot is formed between the limiting ribs (34) and the inner wall of the ring (32); the bottom end of the strip plate (21) can be fitted and inserted into the limiting slot; a set screw is threaded on the limiting rib (34); ③ Assembly of the hoop (23) and the strip plate (21): Take a set of pre-assembled "steel sheet (22)-hoop (23)" components and align each hoop (23) with the corresponding strip plate (21); put the hoop (23) on the corresponding strip plate (21), slide the hoop (23) along the strip plate (21) to adjust its position, and make it fit into the slot (211); Repeat the above operation until all "steel sheet (22) - hoop (23)" components are assembled with strip plate (21) to form a preliminary cage structure; ④ Disassemble the inner lining (2): Hold the indexing frame (3), lift the assembled inner lining (2), and slowly remove it; S4, the inner liner (2) is assembled and fixed to the metal tube (1): Press the circular cage structure to reduce its diameter to less than the inner diameter of the metal tube (1). The steel sheet (22) is pressed and generates elastic force, pushing the circular cage structure from one end of the metal tube (1) into the designed position. Release the pressure, and the steel sheet (22) will naturally expand under the action of elasticity until the second surface of the strip plate (21) is tightly attached to the inner wall of the metal tube (1) to achieve initial positioning; By using a two-end welding method, the two ends of the strip plate (21) are welded and fixed to the inner wall of the metal pipe (1) to complete the assembly of a single pipe unit; Repeat the above steps to complete the processing and assembly of multiple single-section tube units; S5, tube units connected in series: Based on the cooling path design of the gravity dam casting blocks, several single pipe units are connected in series by welding or flanges to form an integral pipeline.

2. The method for manufacturing an assembled concrete cooling pipe structure for gravity dam construction according to claim 1, characterized in that, The steel sheet (22) is spring steel.

3. The method for manufacturing an assembled concrete cooling pipe structure for gravity dam construction according to claim 1, characterized in that, The length of the strip plate (21) is less than or equal to the length of the metal tube (1).

4. The method for manufacturing an assembled concrete cooling pipe structure for gravity dam construction according to claim 1, characterized in that, Adjacent pipe units are connected by welding, flanges, or pipe sections.

5. A method for manufacturing an assembled concrete cooling pipe structure for gravity dam construction according to claim 1, characterized in that, The clamp (23) is made of metal, engineering plastic or composite material.

6. A method for manufacturing an assembled concrete cooling pipe structure for gravity dam construction according to claim 1, characterized in that, The specific usage method of the indexing frame (3) is as follows: a. Positioning and fixing of strip plate (21): Insert the strip plate (21) into each limiting slot, so that the bottom end of the strip plate (21) passes through the limiting slot and is pressed against the upper surface of the base (31); then screw the set screws inward one by one until the set screws press against the side wall of the strip plate (21), forcing the strip plate (21) to fit against the inner wall of the ring (32), thus completing the positioning and fixing of the strip plate (21) on the indexing frame (3); b. Removal of the inner lining (2): When the inner liner (2) needs to be removed, first loosen all the top screws outward, then hold the main body of the inner liner (2) and lift it vertically and steadily until the strip plate (21) is completely removed from the limiting slot, and the overall disassembly is completed.

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