A high-temperature-resistant pressure-bearing structure of a fully-welded plate heat exchanger

Abstract

The utility model provides a kind of high-temperature-resistant pressure-bearing structure of full-welded plate heat exchanger belongs to plate heat exchanger technical field, and the high-temperature-resistant pressure-bearing structure of this full-welded plate heat exchanger includes pressure-bearing shell, corrugated heat transfer plate group, support frame, sealing assembly, inlet and outlet connecting pipe and fixed locking device;Pressure-bearing shell is hollow cylinder of rectangular section, and the both ends of pressure-bearing shell are respectively equipped with end plate, and pressure-bearing shell is equipped with corrugated heat transfer plate group inside, and corrugated heat transfer plate group includes multiple pieces of parallel arrangement's corrugated heat transfer plate, and each corrugated heat transfer plate is stainless steel material and surface is formed with regular corrugated structure;Sealing assembly is located at the both sides of corrugated heat transfer plate group inside pressure-bearing shell, and sealing assembly includes sealing washer and compression ring;The utility model can solve the structural reliability problems such as sealing failure, heat transfer plate deformation, insufficient pressure-bearing capacity of plate heat exchanger under high temperature and high pressure working condition.

Description

Technical Field

[0001] This utility model belongs to the technical field of plate heat exchangers, and specifically relates to a high-temperature pressure-bearing structure for a fully welded plate heat exchanger. Background Technology

[0002] Plate heat exchangers, as highly efficient heat transfer devices, are widely used in heat exchange processes in industries such as petrochemicals, power, metallurgy, and food processing. Traditional plate heat exchangers primarily employ a structure of gaskets and bolted connections. This structure offers advantages such as easy assembly and disassembly and simple maintenance under normal temperature and pressure conditions, and has therefore been widely adopted in general industrial applications. However, with the continuous development of industrial technology, more and more processes require heat exchange operations under high temperature and high pressure conditions, such as hydrogenation reactors in oil refining units, high-pressure synthesis reactors in chemical processes, and supercritical boilers in power systems. These applications place higher demands on the high-temperature and pressure resistance of heat exchangers. Existing gasketed plate heat exchangers are prone to gasket aging, deformation, and even failure under high-temperature environments, leading to media leakage and equipment shutdown. Bolted connections are susceptible to thermal stress loosening under high-temperature and high-pressure conditions, affecting sealing performance and structural stability. The strength and corrosion resistance of traditional heat transfer plate materials and structural designs often fail to meet requirements under high-temperature and high-pressure environments, making them prone to deformation, cracking, and even damage. Existing support structure designs typically only consider ambient temperature conditions, and are insufficient in terms of thermal expansion deformation and load-bearing capacity under high-temperature environments. To address these technical issues, engineers have tried various improvement schemes, including using high-temperature sealing materials, increasing bolt preload, and improving heat transfer plate materials. However, these solutions often only provide improvements in certain aspects and cannot fundamentally solve the comprehensive technical problems under high-temperature and high-pressure conditions. Utility Model Content

[0003] In view of this, the present invention provides a high-temperature pressure-bearing structure for a fully welded plate heat exchanger, which can solve the structural reliability problems of plate heat exchangers under high temperature and high pressure conditions, such as sealing failure, heat transfer plate deformation, and insufficient pressure bearing capacity.

[0004] This utility model is implemented as follows: This utility model provides a high-temperature pressure-bearing structure for a fully welded plate heat exchanger, comprising a pressure-bearing shell, a corrugated heat transfer plate assembly, a support frame, a sealing component, inlet and outlet pipes, and a fixing and locking device. The pressure-bearing shell is a hollow cylinder with a rectangular cross-section, and end plates are provided at both ends of the pressure-bearing shell. The pressure-bearing shell is equipped with a corrugated heat transfer plate assembly, which includes multiple corrugated heat transfer plates arranged in parallel. Each corrugated heat transfer plate is made of stainless steel and has a regular corrugated structure on its surface. The support frame is fixedly installed at the bottom of the pressure-bearing shell and includes a base and at least four columns. The upper ends of the columns are fully welded to the bottom surface of the pressure-bearing shell. Connections; The sealing assembly is located on both sides of the corrugated heat transfer plate assembly inside the pressure-bearing shell. The sealing assembly includes a sealing gasket and a clamping ring. The sealing gasket is made of high-temperature resistant rubber and has a ring structure. The clamping ring is fixedly connected to the inner wall of the pressure-bearing shell by bolts. The inlet and outlet pipes are respectively set on opposite sides of the pressure-bearing shell. One end of the inlet and outlet pipes is connected to the side wall of the pressure-bearing shell by full welding, and the other end extends to the outside of the pressure-bearing shell. The fixing and locking device includes a locking screw and a locking nut. The locking screw passes through the end plate of the pressure-bearing shell and is connected to the end of the corrugated heat transfer plate assembly. The locking nut is screwed on the outer end of the locking screw to apply a preload to the corrugated heat transfer plate assembly.

[0005] The technical advantages of the high-temperature pressure-bearing structure of the all-welded plate heat exchanger provided by this utility model are as follows: By organically combining the pressure-bearing shell, corrugated heat transfer plate assembly, support frame, sealing components, inlet and outlet pipes, and fixing and locking device, a complete high-temperature pressure-bearing heat transfer system is constructed. The pressure-bearing shell provides a stable pressure-bearing space for the heat transfer plate assembly. The corrugated heat transfer plate assembly significantly increases the heat transfer area through its regular corrugated structure. The support frame provides a stable structural foundation for the entire device. The sealing components ensure the sealing reliability under high-temperature and high-pressure conditions. The inlet and outlet pipes enable the orderly entry and exit of fluids. The fixing and locking device ensures the stable assembly of the heat transfer plate assembly. The overall structural design is reasonable and the components work in coordination, effectively improving the high-temperature pressure resistance and heat transfer efficiency of the heat exchanger.

[0006] Based on the above technical solution, the high-temperature pressure-bearing structure of the all-welded plate heat exchanger of this utility model can be further improved as follows: The corrugated heat transfer plate assembly consists of a plate with a thickness of 2 mm to 8 mm, a corrugation height of 5 mm to 15 mm, and a spacing of 10 mm to 30 mm between adjacent plates. The corrugated heat transfer plates are made of 316L stainless steel and have a herringbone corrugated structure with an angle of 60 degrees to 120 degrees.

[0007] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by precisely controlling key dimensional parameters such as the thickness, corrugation height, inter-plate spacing, and herringbone corrugation angle of the corrugated heat transfer plate, the heat transfer performance and strength characteristics of the heat transfer plate are optimized. The selection of 316L stainless steel material ensures the stability of the heat transfer plate in a high-temperature corrosive environment. The herringbone corrugated structure forms a turbulent heat transfer effect, which significantly improves the heat transfer coefficient. At the same time, the reasonable inter-plate spacing ensures smooth fluid flow and avoids the problem of excessive pressure loss. The overall parameter optimization design achieves the best balance between heat transfer efficiency and structural strength.

[0008] Furthermore, the shell thickness of the pressure vessel is 15 mm to 25 mm, and the material of the pressure vessel is Q345R pressure vessel steel plate; the inner surface of the pressure vessel is provided with multiple longitudinal reinforcing ribs, which are evenly distributed and connected to the inner wall of the pressure vessel by full welding. The cross-sectional shape of the longitudinal reinforcing ribs is T-shaped, and the web height of the T-shaped reinforcing ribs is 20 mm to 40 mm.

[0009] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the pressure-bearing shell is made of Q345R pressure vessel steel plate and the appropriate shell wall thickness is controlled to ensure structural safety under high temperature and high pressure conditions. The setting of longitudinal stiffeners effectively enhances the compressive strength and deformation resistance of the pressure-bearing shell. The T-section stiffener design provides the best reinforcement effect. The fully welded connection between the stiffeners and the shell ensures the reliability and sealing of the connection. The overall structural design gives the pressure-bearing shell excellent pressure resistance performance and can withstand higher working pressures, providing a reliable guarantee for the safe operation of the heat exchanger under extreme conditions.

[0010] Furthermore, the base of the supporting frame is a rectangular steel plate structure with a thickness of 20 mm to 35 mm, and mounting holes are provided at the four corners of the base; the column is a steel pipe with a circular cross-section, an outer diameter of 100 mm to 200 mm, and a wall thickness of 10 mm to 20 mm. The connection between the column and the base is provided with a reinforcing plate, which has a triangular structure and is connected to both the column and the base by full welding.

[0011] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the support frame adopts a rectangular steel plate base combined with a circular cross-section column design, which provides a stable and reliable support foundation for the heat exchanger. The mounting holes at the four corners of the base facilitate the installation and fixing of the equipment. The circular cross-section of the column has good compressive and bending resistance. The reasonable wall thickness design reduces weight while ensuring strength. The triangular structure of the reinforcing plate effectively enhances the local strength of the connection between the column and the base. The fully welded connection method ensures the firmness of the connection. The overall support frame design is scientific and reasonable, which can stably support the operation of the heat exchanger under various working conditions and ensure the structural stability of the equipment.

[0012] Furthermore, the sealing gasket of the sealing assembly has an O-shaped cross-section, with a wire diameter of 3 mm to 8 mm and a material of fluororubber; the clamping ring has an annular steel plate structure, a radial width of 15 mm to 30 mm, and a clearance of 0.5 mm to 2 mm between the clamping ring and the inner wall of the pressure-bearing housing.

[0013] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The sealing assembly adopts an O-shaped cross-section fluororubber sealing gasket combined with an annular steel plate compression ring, which realizes reliable sealing under high temperature and high pressure environment. Fluororubber material has excellent high temperature resistance and chemical corrosion resistance. The O-shaped cross-section design provides a good sealing contact surface. The annular steel plate structure of the compression ring provides uniform compression force for the sealing gasket. The reasonable radial width and fitting clearance ensure the effectiveness of sealing and the convenience of assembly. The overall sealing assembly is scientifically designed, effectively preventing the leakage of high temperature media and ensuring the sealing reliability and safe operation of the heat exchanger.

[0014] Furthermore, the diameter of the inlet and outlet pipes is 100 mm to 300 mm, and the wall thickness of the inlet and outlet pipes is 8 mm to 16 mm; a reinforcing plate is provided at the connection between the inlet and outlet pipes and the pressure shell. The reinforcing plate has a circular structure and its outer diameter is 1.5 times larger than the outer diameter of the pipe. The thickness of the reinforcing plate is 12 mm to 20 mm. The reinforcing plate is connected to the pressure shell and the inlet and outlet pipes by full welding.

[0015] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the inlet and outlet pipes, through reasonable pipe diameter and wall thickness design, meet the usage requirements of different flow and pressure levels; the setting of the reinforcing plate effectively enhances the local strength of the connection between the pipe and the pressure shell; the outer diameter design of the circular reinforcing plate ensures sufficient reinforcement area; the appropriate thickness provides the necessary strength support; the all-welded connection method ensures the sealing and reliability of the connection; the overall pipe design not only meets the functional requirements of fluid transportation, but also ensures the structural strength of the connection, effectively avoids structural failure caused by stress concentration, and improves the overall reliability of the heat exchanger.

[0016] Furthermore, the corrugated structure of the corrugated heat transfer plate includes crests and troughs, with the top of the crests being arc-shaped and the bottom of the troughs being V-shaped grooves.

[0017] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the crest of the corrugated heat transfer plate adopts an arc shape design, which effectively avoids the stress concentration problem that may be caused by the sharp corner structure and improves the fatigue resistance of the heat transfer plate. The V-shaped groove at the bottom of the trough enhances the turbulence effect of the fluid and promotes the heat transfer process. At the same time, the V-shaped groove structure has good self-cleaning ability, reducing the accumulation of dirt. The reasonable combination of crests and troughs forms an optimized heat transfer channel, which not only ensures the improvement of heat transfer efficiency, but also enhances the structural strength of the heat transfer plate. The overall corrugated shape design achieves an effective unity of heat transfer performance and mechanical performance.

[0018] Furthermore, the cross-sectional shape of the pressure-bearing shell is rectangular, and the four corners of the rectangle are rounded with a radius of 10 mm to 25 mm.

[0019] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: The pressure shell adopts a rectangular cross-section design, which provides a larger internal space utilization rate, facilitates the arrangement and assembly of heat transfer plate groups, and the rounded corner transition design at the four corners effectively eliminates the stress concentration phenomenon that may be caused by the right-angle structure, improves the compressive strength and fatigue resistance of the pressure shell, and the reasonable rounded corner radius not only ensures the structural strength, but also facilitates processing and manufacturing. The rectangular cross-section combined with the rounded corner transition design gives the pressure shell excellent mechanical properties, enabling it to withstand higher working pressure, while ensuring the compactness and economy of the structure.

[0020] Furthermore, the locking screw of the fixing and locking device is made of high-temperature alloy steel, with a diameter of 20 mm to 50 mm and a trapezoidal thread.

[0021] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the locking device uses a locking screw made of high-temperature alloy steel, which ensures the stability of mechanical performance in high-temperature environments. The reasonable screw diameter design provides sufficient strength and rigidity. The trapezoidal thread structure has good self-locking performance and force transmission characteristics, which can provide stable and reliable pre-tightening force, effectively fixing the position of the heat transfer plate assembly and preventing displacement and deformation of the heat transfer plate under high temperature and high pressure conditions. The reliable design of the locking device ensures the structural integrity of the heat exchanger for long-term stable operation, and improves the service life and safety of the equipment.

[0022] Furthermore, the supporting frame has four columns, which are equidistantly distributed at the four corners of the base, and there are at least six longitudinal reinforcing ribs.

[0023] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the support frame adopts a design with 4 columns evenly distributed at the four corners of the base, forming a stable four-point support structure, which effectively disperses the weight load of the heat exchanger and improves the stability of the support. The configuration of more than 6 longitudinal stiffeners provides sufficient structural reinforcement for the pressure-bearing shell. The reasonable number and distribution of stiffeners ensure the pressure resistance of the pressure-bearing shell in all directions. The optimized design of the overall quantity configuration not only ensures the structural strength requirements but also controls the manufacturing cost, achieving a good balance between economy and reliability.

[0024] Compared with existing technologies, the beneficial effects of the high-temperature pressure-bearing structure of the all-welded plate heat exchanger provided by this utility model are as follows: Through the all-welded structural design and the selection of high-temperature pressure-bearing materials, the structural reliability problem of traditional plate heat exchangers under high-temperature and high-pressure environments is fundamentally solved. The pressure-bearing shell uses Q345R pressure vessel steel plate with longitudinal reinforcing ribs, significantly improving the overall pressure-bearing capacity and enabling it to withstand higher working pressures. The corrugated heat transfer plate assembly uses 316L stainless steel and an optimized herringbone corrugated structure, ensuring material stability under high-temperature environments while significantly improving heat transfer efficiency. The sealing assembly uses a design of fluororubber O-rings combined with a compression ring, achieving reliable sealing under high-temperature and high-pressure conditions and effectively preventing media leakage. The all-welded connection method completely eliminates the risk of loosening and leakage that may occur with bolted connections, significantly improving the overall integrity and reliability of the structure. The rational design of the support frame and fixing locking device ensures the structural stability of the heat exchanger under various operating conditions, effectively extending the service life of the equipment. The overall technical solution has achieved a comprehensive improvement in heat transfer efficiency, pressure bearing capacity, sealing reliability and structural stability, providing a reliable technical solution for high-temperature and high-pressure heat exchange applications. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a high-temperature pressure-bearing structure for a fully welded plate heat exchanger. Figure 2 This is a partial upper view of the interior of the pressure-bearing shell. The attached diagram lists the components represented by each number as follows: 10. Pressure-bearing shell; 11. Corrugated heat transfer plate assembly; 12. Support frame; 13. Sealing assembly; 14. Inlet and outlet pipes; 15. Fixing and locking device; 16. End plate; 17. Corrugated heat transfer plate; 18. Column; 19. Sealing gasket; 20. Compression ring; 21. Locking screw; 22. Locking nut; 23. Reinforcing plate. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0028] like Figure 1 Figure 2 shows an embodiment of a high-temperature pressure-bearing structure for a fully welded plate heat exchanger provided by this utility model. In this embodiment, it includes a pressure-bearing shell 10, a corrugated heat transfer plate assembly 11, a support frame 12, a sealing assembly 13, inlet and outlet pipes 14, and a fixing and locking device 15. The pressure-bearing shell is a hollow cylinder with a rectangular cross-section. End plates 16 are provided at both ends of the pressure-bearing shell. The pressure-bearing shell is equipped with a corrugated heat transfer plate assembly, which includes multiple corrugated heat transfer plates 17 arranged in parallel. Each corrugated heat transfer plate is made of stainless steel and has a regular corrugated structure on its surface. The support frame is fixedly installed at the bottom of the pressure-bearing shell. The support frame includes a base and at least four columns 18. The upper ends of the columns are connected to the pressure-bearing shell. The bottom surface of the shell is connected by full welding. The sealing assembly is located on both sides of the corrugated heat transfer plate assembly inside the pressure shell. The sealing assembly includes a sealing gasket 19 and a compression ring 20. The sealing gasket is made of high-temperature resistant rubber and has a ring structure. The compression ring is fixedly connected to the inner wall of the pressure shell by bolts. The inlet and outlet pipes are respectively set on opposite sides of the pressure shell. One end of the inlet and outlet pipes is connected to the side wall of the pressure shell by full welding, and the other end extends to the outside of the pressure shell. The fixing and locking device includes a locking screw 21 and a locking nut 22. The locking screw passes through the end plate of the pressure shell and is connected to the end of the corrugated heat transfer plate assembly. The locking nut is screwed on the outer end of the locking screw to apply a preload to the corrugated heat transfer plate assembly.

[0029] In the above technical solution, the thickness of each corrugated heat transfer plate in the corrugated heat transfer plate assembly is 2 mm to 8 mm, the corrugation height of the corrugated heat transfer plate is 5 mm to 15 mm, and the spacing between two adjacent corrugated heat transfer plates is 10 mm to 30 mm; the material of the corrugated heat transfer plate is 316L stainless steel, and the surface of the corrugated heat transfer plate adopts a herringbone corrugated structure with an angle of 60 degrees to 120 degrees.

[0030] Furthermore, in the above technical solution, the shell thickness of the pressure-bearing shell is 15 mm to 25 mm, and the material of the pressure-bearing shell is Q345R pressure vessel steel plate; the inner surface of the pressure-bearing shell is provided with multiple longitudinal reinforcing ribs, which are evenly distributed and connected to the inner wall of the pressure-bearing shell by full welding. The cross-sectional shape of the longitudinal reinforcing ribs is T-shaped, and the web height of the T-shaped reinforcing ribs is 20 mm to 40 mm.

[0031] Furthermore, in the above technical solution, the base of the support frame is a rectangular steel plate structure with a thickness of 20 mm to 35 mm, and mounting holes are provided at the four corners of the base; the column is a steel pipe with a circular cross-section, with an outer diameter of 100 mm to 200 mm and a wall thickness of 10 mm to 20 mm, and a reinforcing plate is provided at the connection between the column and the base. The reinforcing plate has a triangular structure and is connected to both the column and the base by full welding.

[0032] Furthermore, in the above technical solution, the sealing gasket of the sealing component has an O-shaped cross-section, the wire diameter of the O-shaped sealing gasket is 3 mm to 8 mm, and the material of the sealing gasket is fluororubber; the clamping ring is an annular steel plate structure, the radial width of the clamping ring is 15 mm to 30 mm, and the fitting clearance between the clamping ring and the inner wall of the pressure-bearing housing is 0.5 mm to 2 mm.

[0033] Furthermore, in the above technical solution, the diameter of the inlet and outlet pipes is 100 mm to 300 mm, and the wall thickness of the inlet and outlet pipes is 8 mm to 16 mm; a reinforcing plate 23 is provided at the connection between the inlet and outlet pipes and the pressure-bearing shell. The reinforcing plate has a circular structure and its outer diameter is 1.5 times larger than the outer diameter of the pipe. The thickness of the reinforcing plate is 12 mm to 20 mm. The reinforcing plate is connected to the pressure-bearing shell and the inlet and outlet pipes by full welding.

[0034] Furthermore, in the above technical solution, the corrugated structure of the corrugated heat transfer plate includes crests and troughs, with the top of the crests being arc-shaped and the bottom of the troughs being V-shaped grooves.

[0035] Furthermore, in the above technical solution, the cross-sectional shape of the pressure-bearing shell is rectangular, and the four corners of the rectangle are provided with rounded transitions, with the radius of the rounded corners ranging from 10 mm to 25 mm.

[0036] Furthermore, in the above technical solution, the locking screw of the fixing and locking device is made of high-temperature alloy steel, the diameter of the locking screw is 20 mm to 50 mm, and the thread of the locking screw is a trapezoidal thread.

[0037] Furthermore, in the above technical solution, the supporting frame has 4 columns, which are equidistantly distributed at the four corners of the base, and the number of longitudinal reinforcing ribs is at least 6.

[0038] The method of using this utility model is as follows: First, prepare for the installation of the heat exchanger by fixing the base of the support frame to the pre-set foundation with bolts, ensuring the levelness and stability of the support frame. Then, hoist the pressure shell onto the support frame using lifting equipment and weld it to the columns of the support frame. Next, assemble the corrugated heat transfer plate assembly by placing the pre-fabricated corrugated heat transfer plates into the pressure shell according to the design spacing, ensuring that each heat transfer plate is accurately positioned and parallel to each other. At the same time, install the sealing gasket and clamping ring in the sealing assembly, and fix the clamping ring to the inner wall of the pressure shell with bolts to form a reliable sealing structure. Subsequently, weld and install the inlet and outlet pipes by fully welding the inlet and outlet pipes to the reserved interfaces of the pressure shell, and weld reinforcing plates to enhance the strength of the connection. After welding, perform non-destructive testing to ensure the welding quality. Then, the corrugated heat transfer plate assembly is secured using a fixing and locking device. The locking screws are passed through the end plates of the pressure-bearing shell and connected to the heat transfer plate assembly. Appropriate preload is applied to the heat transfer plate assembly by tightening the locking nuts to ensure its stable position under high temperature and high pressure conditions. Finally, a system pressure test and leak detection are conducted. The pressure is gradually increased to 1.25 times the design pressure for a pressure holding test. The sealing performance of all connections and welds is checked. Once no leaks are confirmed, the system can be put into normal use. During daily operation, the stability of the support frame, the connection status of the inlet and outlet pipes, and the integrity of the overall structure need to be checked regularly to promptly identify and address any potential problems, ensuring the safe and reliable operation of the heat exchanger.

[0039] The following is a specific embodiment 1 of this utility model: This embodiment provides a high-temperature pressure-bearing structure for a fully welded plate heat exchanger applied in a petrochemical plant, with a designed working pressure of 4.0 MPa and a working temperature of 350 degrees Celsius. The pressure-bearing shell adopts a rectangular cross-section structure with dimensions of 2000 mm × 1500 mm × 3000 mm. The shell material is Q345R pressure vessel steel plate with a wall thickness of 20 mm, and rounded corners with a radius of 15 mm at the four corners. Eight longitudinal reinforcing ribs are evenly distributed on the inner surface of the pressure-bearing shell. The reinforcing ribs adopt a T-section design, with a web height of 30 mm, a flange width of 80 mm, and a thickness of 12 mm. The reinforcing ribs are connected to the inner wall of the shell by double-sided continuous fillet welds with a weld height of 8 mm. The corrugated heat transfer plate assembly includes 60 corrugated heat transfer plates, each with dimensions of 1800 mm × 1300 mm, a plate thickness of 5 mm, and a material of 316L stainless steel. The surface of the heat transfer plate is processed with herringbone corrugations, the corrugation height is 10 mm, the herringbone angle is 90 degrees, and the distance between two adjacent heat transfer plates is 20 mm.

[0040] The base of the supporting frame is made of a rectangular steel plate measuring 2500 mm × 2000 mm, with a thickness of 25 mm, and is made of Q235B carbon structural steel. The four uprights are made of seamless steel pipes with an outer diameter of 150 mm and a wall thickness of 15 mm. The uprights are 1200 mm high, and triangular reinforcing plates with a thickness of 16 mm are installed at the connection between the uprights and the base. The sealing components use fluororubber O-rings with a wire diameter of 5 mm, a Shore A hardness of 75, and a temperature resistance range of -30°C to +200°C.

[0041] The clamping ring is constructed from a ring-shaped steel plate with an inner diameter of 80 mm, an outer diameter of 120 mm, and a thickness of 15 mm, made of No. 45 carbon structural steel. The inlet and outlet pipes are seamless steel pipes with an outer diameter of 200 mm and a wall thickness of 12 mm, made of No. 20 carbon structural steel, and are 800 mm in length. The reinforcing plate is a circular steel plate with an outer diameter of 300 mm and a thickness of 16 mm, and is connected to the pipes and the pressure-bearing shell by full penetration welding.

[0042] The locking screw of the fixing and locking device is made of 30 mm diameter high-temperature alloy steel, with a 1Cr18Ni9Ti stainless steel material and a trapezoidal thread specification of Tr30×6. The locking nut is a hexagonal nut of the corresponding specification, made of the same material as the screw. The heat transfer area of ​​the entire heat exchanger is 468 square meters, and the total weight of the equipment is approximately 8.5 tons. This embodiment has a reasonable structural design and appropriate material selection for each component, which can meet the requirements of high-temperature and high-pressure processes in petrochemicals. It has good heat transfer efficiency and structural reliability, and its expected service life is over 20 years.

[0043] In practical applications, this heat exchanger can be used in processes such as crude oil preheating, heavy oil heating, and heat recovery in catalytic cracking units. Through its efficient heat transfer performance and reliable structural design, it provides important technical support for petrochemical production.

[0044] The following is another specific embodiment 2 of this utility model: Embodiment 2 is an optimization and improvement based on Embodiment 1, specifically for supercritical boiler applications in the power industry. The working pressure is increased to 6.0 MPa, and the working temperature is increased to 450 degrees Celsius. The wall thickness of the pressure-bearing shell is increased to 25 mm, the number of longitudinal reinforcing ribs is increased to 12, and the web height of the reinforcing ribs is increased to 40 mm to enhance pressure resistance. The corrugated heat transfer plate material is upgraded to 310S heat-resistant stainless steel, which has superior high-temperature oxidation resistance, and the heat transfer plate thickness is increased to 6 mm to improve high-temperature strength.

[0045] The sealing assembly adopts an all-metal sealing structure, eliminating the rubber sealing ring and replacing it with a metal C-type sealing ring made of Inconel 625 nickel-based high-temperature alloy, which can withstand higher operating temperatures. The wall thickness of the support frame column has been increased to 20 mm, the base thickness to 30 mm, and a transverse support beam has been added in the middle of the column to improve overall rigidity.

[0046] The locking screw of the fixed locking device has been upgraded to Inconel 718 nickel-based high-temperature alloy, with its diameter increased to 40 mm and the thread specification adjusted accordingly to Tr40×7. The material of the inlet and outlet pipes has been upgraded to 12Cr1MoV alloy steel, and the thickness of the reinforcing plate has been increased to 20 mm.

[0047] This embodiment achieves reliable operation under higher temperature and pressure conditions through material upgrades and structural reinforcement, making it suitable for feedwater heating systems of supercritical and ultra-supercritical thermal power units and significantly improving the unit's thermal efficiency. The entire improvement scheme, while maintaining the original structural advantages, further enhances adaptability under extreme operating conditions, providing technical support for the high-parameter development of the power industry.

[0048] The following is another specific embodiment 3 of this utility model: Embodiment 3 is based on Embodiment 1, and is specifically designed and optimized for application needs in corrosive environments such as marine platforms. The pressure-bearing shell material is upgraded to 316L stainless steel composite steel plate, with the inner layer of 316L stainless steel providing corrosion resistance and the outer layer of Q345R steel plate providing strength support. The total thickness of the composite plate is 22 mm. The longitudinal reinforcing ribs are also made of 316L stainless steel and undergo electrolytic polishing to improve corrosion resistance. The corrugated heat transfer plate is made of duplex stainless steel 2205, which has excellent resistance to chloride ion corrosion and high strength characteristics. The surface of the heat transfer plate is passivated to enhance corrosion resistance.

[0049] The sealing assembly employs a composite sealing structure of PTFE-coated fluororubber. The outer PTFE layer provides chemical inertness, while the inner fluororubber layer provides elastic sealing capability. The entire support frame is made of 316L stainless steel, with electrochemical polishing and passivation treatment. Stainless steel bushings are installed in the mounting holes at the four corners of the base to prevent electrochemical corrosion. The inlet and outlet pipes are made of super duplex stainless steel 2507, which has extremely strong resistance to seawater corrosion. The connection between the pipes and the pressure shell is achieved using dissimilar steel welding technology, and the weld area undergoes stress-relieving heat treatment.

[0050] The screws and nuts of the fixing and locking device are made of Hastelloy C-276 nickel-based alloy with chemical passivation treatment and anti-seize lubricant applied to the threaded parts. The entire outer surface of the heat exchanger is coated with a composite anti-corrosion coating system of epoxy zinc-rich primer and fluorocarbon topcoat, with a total coating thickness of 250 micrometers.

[0051] This embodiment, through comprehensive selection of corrosion-resistant materials and protective measures, can operate stably for extended periods in harsh corrosive environments such as the marine atmosphere, seawater splash, and salt spray, with a designed service life of 25 years. It is particularly suitable for heat exchange applications in marine engineering fields such as offshore oil platforms, seawater desalination plants, and ship propulsion systems, providing reliable technical support for marine resource development. Despite increased material costs, this embodiment significantly reduces maintenance costs and downtime losses due to its superior corrosion resistance, demonstrating excellent economic and social benefits.

[0052] Specifically, the principle of this utility model is as follows: By adopting a fully welded structural design concept and eliminating the weak links of traditional bolt connections and gaskets, the sealing and strength problems under high temperature and high pressure environments are fundamentally solved structurally. The pressure-bearing shell, as the main pressure-bearing component, uses Q345R steel specifically for pressure vessels and employs a scientifically designed wall thickness to ensure structural safety under high temperature and high pressure conditions. Internal longitudinal reinforcing ribs form an effective pressure-resistant skeleton, significantly improving pressure-bearing capacity. The corrugated heat transfer plate assembly uses high-temperature corrosion-resistant 316L stainless steel. Through an optimized herringbone corrugated structure design, it maintains good heat transfer performance and structural strength even under high temperature environments. The turbulence effect generated by the corrugated structure effectively enhances the heat transfer process. The sealing component uses high-temperature resistant fluororubber material and an O-ring seal structure. Combined with the uniform compression of the clamping ring, reliable sealing under high temperature and high pressure conditions is achieved. The excellent temperature resistance of fluororubber ensures the long-term stability of the sealing effect. The fully welded connection method completely eliminates the loosening and leakage problems that may occur with mechanical connections. The metallic continuity of the welded joint ensures that the connection part has the same strength and sealing performance as the base material. The support frame, with its four-point support and triangular reinforcing plate design, provides a stable and reliable structural foundation for the heat exchanger, capable of withstanding thermal expansion stress under high-temperature conditions. The fixing and locking device, made of high-temperature alloy steel and featuring a trapezoidal thread design, provides stable preload even in high-temperature environments, ensuring the assembly stability of the heat transfer plate assembly. This achieves reliable heat transfer and long-term stable operation under high-temperature and high-pressure conditions.

Claims

1. A high-temperature pressure-bearing structure for a fully welded plate heat exchanger, characterized in that, The system includes a pressure-bearing shell, a corrugated heat transfer plate assembly, a support frame, a sealing component, inlet and outlet pipes, and a fixing and locking device. The pressure-bearing shell is a hollow cylinder with a rectangular cross-section. End plates are provided at both ends of the pressure-bearing shell. The pressure-bearing shell contains a corrugated heat transfer plate assembly, which consists of multiple parallel corrugated heat transfer plates, each made of stainless steel with a regularly corrugated surface. The support frame is fixedly installed at the bottom of the pressure-bearing shell and includes a base and at least four columns. The upper ends of the columns are connected to the bottom surface of the pressure-bearing shell by full welding. The sealing component is located inside the pressure-bearing shell. On both sides of the corrugated heat transfer plate assembly, the sealing components include sealing gaskets and compression rings. The sealing gaskets are made of high-temperature resistant rubber and have a ring structure. The compression rings are fixedly connected to the inner wall of the pressure-bearing shell by bolts. The inlet and outlet pipes are respectively set on opposite sides of the pressure-bearing shell. One end of the inlet and outlet pipes is connected to the side wall of the pressure-bearing shell by full welding, and the other end extends to the outside of the pressure-bearing shell. The fixing and locking device includes a locking screw and a locking nut. The locking screw passes through the end plate of the pressure-bearing shell and is connected to the end of the corrugated heat transfer plate assembly. The locking nut is screwed on the outer end of the locking screw to apply a preload to the corrugated heat transfer plate assembly.

2. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 1, characterized in that, Each corrugated heat transfer plate in the corrugated heat transfer plate assembly has a thickness of 2 mm to 8 mm, a corrugation height of 5 mm to 15 mm, and a spacing of 10 mm to 30 mm between two adjacent corrugated heat transfer plates. The corrugated heat transfer plates are made of 316L stainless steel, and the surface of the corrugated heat transfer plates adopts a herringbone corrugated structure with an angle of 60 degrees to 120 degrees.

3. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 2, characterized in that, The shell thickness of the pressure vessel is 15 mm to 25 mm, and the material of the pressure vessel is Q345R pressure vessel steel plate. The inner surface of the pressure vessel is provided with multiple longitudinal stiffeners, which are evenly distributed and connected to the inner wall of the pressure vessel by full welding. The cross-sectional shape of the longitudinal stiffeners is T-shaped, and the web height of the T-shaped stiffeners is 20 mm to 40 mm.

4. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 3, characterized in that, The base of the supporting frame is a rectangular steel plate structure with a thickness of 20 mm to 35 mm. Mounting holes are provided at the four corners of the base. The columns are steel pipes with a circular cross-section, an outer diameter of 100 mm to 200 mm, and a wall thickness of 10 mm to 20 mm. The connection between the columns and the base is equipped with a reinforcing plate. The reinforcing plate has a triangular structure and is connected to both the columns and the base by full welding.

5. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 4, characterized in that, The sealing gasket of the sealing assembly has an O-shaped cross-section, with a wire diameter of 3 mm to 8 mm and made of fluororubber. The clamping ring is an annular steel plate structure with a radial width of 15 mm to 30 mm and a clearance of 0.5 mm to 2 mm between the clamping ring and the inner wall of the pressure-bearing housing.

6. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 5, characterized in that, The diameter of the inlet and outlet pipes is 100 mm to 300 mm, and the wall thickness of the inlet and outlet pipes is 8 mm to 16 mm. The connection between the inlet and outlet pipes and the pressure shell is equipped with a reinforcing plate. The reinforcing plate has a circular structure and its outer diameter is 1.5 times larger than the outer diameter of the pipe. The thickness of the reinforcing plate is 12 mm to 20 mm. The reinforcing plate is connected to the pressure shell and the inlet and outlet pipes by full welding.

7. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 6, characterized in that, The corrugated structure of the corrugated heat transfer plate includes crests and troughs. The top of the crest is arc-shaped, and the bottom of the trough is V-shaped.

8. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 7, characterized in that, The pressure-bearing shell has a rectangular cross-sectional shape, with rounded corners at all four corners, the radius of which is 10 mm to 25 mm.

9. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 8, characterized in that, The locking screw of the fixed locking device is made of high-temperature alloy steel, with a diameter of 20 mm to 50 mm and a trapezoidal thread.

10. The high-temperature pressure-bearing structure of a fully welded plate heat exchanger according to claim 9, characterized in that, The supporting frame has four columns, which are equidistantly distributed at the four corners of the base, and there are at least six longitudinal reinforcing ribs.

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