Aluminum alloy tubular heat exchanger

Abstract

The invention relates to the technical field of heat exchange equipment, and discloses an aluminum alloy tubular heat exchanger which comprises a cylindrical shell, the inner space of the cylindrical shell is divided into a plurality of cavities sequentially arranged in the axial direction by a plurality of partition baffles, a multi-cavity structure with traditional cavities and common cavities arranged alternately is formed, an inlet pipeline and an outlet pipeline are arranged on the shell side, and the shell side is provided with an inlet pipe and an outlet pipe. The heating medium forms a heating medium loop between the inlet pipeline and the outlet pipeline; the heat exchange tube bundle is arranged in the cylindrical shell and penetrates through the partition baffle, and the two ends of the heat exchange tube bundle are connected with a fluid pipeline and downstream process equipment respectively. Through the synergistic effect of the variable-pitch main spiral flow deflectors, the secondary micro flow guide elements arranged in a staggered mode and the V-shaped micro steering sheets, a complex three-dimensional flow mode is formed, the microorganism breeding problem of a heat exchanger in the biopharmaceutical industry under the low-flow-speed working condition is solved, the equipment operation safety and the product quality are improved, and the production cost is reduced. And meanwhile, high heat exchange efficiency and cleaning convenience are kept.

Description

Technical Field

[0001] The present invention relates to the field of heat exchange equipment, and more particularly to an aluminum alloy tubular heat exchanger. Background Art

[0002] Multi-chamber inlet area optimized shell and tube heat exchangers are used in fermentation process temperature control systems in the biopharmaceutical industry. By alternating the conventional shell and tube areas with the common cavity, the high heat transfer characteristics of the fluid inlet area are fully utilized to improve the overall heat transfer efficiency.

[0003] Under low flow rate conditions (Reynolds number <2000), the fluids in the common cavity are not fully mixed, forming local low-velocity areas and dead zones. Microorganisms can easily multiply and form biofilms in these areas. This biofilm not only reduces heat transfer efficiency but also pollutes the production environment, resulting in an increase in the rejection rate of product batches. Conventional chemical cleaning agents are difficult to completely remove the biological contamination in these special areas. Summary of the Invention

[0004] The present invention provides an aluminum alloy tubular heat exchanger to solve the technical problem in the related art that fluids in a common cavity are not mixed sufficiently, forming local low-speed areas and dead zones, and microorganisms are prone to multiply and form biofilms in these areas.

[0005] The present invention provides an aluminum alloy tubular heat exchanger, comprising: The cylindrical shell has an internal space divided by multiple partition baffles into several chambers arranged in sequence along the axial direction, forming a multi-chamber structure in which traditional chambers and common chambers are arranged alternately. An inlet pipe and an outlet pipe are provided on the shell side, and a heat medium forms a heat medium circuit between the inlet pipe and the outlet pipe; The heat exchange tube bundle is arranged inside the cylindrical shell and passes through the partition baffle. The two ends of the heat exchange tube bundle are respectively connected to the fluid pipeline and the downstream process equipment; The multi-stage gradient spiral guide system is installed in a common cavity and includes a main spiral guide vane, a secondary micro guide element and a V-shaped micro steering vane. The main spiral guide vane is installed on the inner wall of the common cavity, the secondary micro guide element is connected to the main spiral guide vane through a connector, and the V-shaped micro steering vane is set on the wall and dead corner area of ​​the common cavity. The three are used to form a complex three-dimensional flow pattern of the fluid.

[0006] Furthermore, both ends of the heat exchange tube bundle are fixedly connected to the tube sheets at both ends of the cylindrical shell, and the tube sheets are connected and sealed to the cylindrical shell through flanges.

[0007] Furthermore, a V-shaped micro-steering blade is added to the wall surface and dead corner area of ​​the common cavity. The V-shaped micro-steering blade includes a substrate and two steering blades. The two steering blades are symmetrically arranged on the substrate. The angle between the two steering blades is 30-60 degrees, forming a V-shaped structure with the opening direction facing the main channel.

[0008] Furthermore, the main spiral guide vane is a sheet-like structure, extending radially inward from the inner wall of the cylindrical shell. The main spiral guide vane adopts a variable pitch design. The spiral angle of the main spiral guide vane near the fluid inlet end is 25-30 degrees, the spiral angle of the main spiral guide vane in the middle of the common cavity is 20-25 degrees, and the spiral angle of the main spiral guide vane near the fluid outlet end is 15-20 degrees, forming a pitch gradient from large to small.

[0009] Furthermore, the main spiral guide vane is connected to the inner wall of the common cavity through a detachable fixing component. The detachable fixing component is a slot structure evenly distributed along the circumference of the inner wall of the cylindrical shell. The wall end of the main spiral guide vane is provided with a corresponding snap structure. The main spiral guide vane and the cylindrical shell are fixed through the cooperation of the snap structure and the slot structure.

[0010] Furthermore, the secondary micro-flow-guiding element includes an arc-shaped substrate and a plurality of spoilers fixed on the arc-shaped substrate. The length of the arc-shaped substrate in the circumferential direction is approximately 1 / 4 to 1 / 6 of the inner circumference of the cylindrical shell. The plurality of spoilers are arranged perpendicular to the surface of the arc-shaped substrate. The height of the spoilers is 1 / 3 of the height of the main spiral guide vanes.

[0011] Furthermore, the spoiler direction of the secondary micro-flow guide element and the guide direction of the main spiral guide vane form an angle of 15-30 degrees.

[0012] Furthermore, the secondary micro flow-guiding elements are arranged between adjacent main spiral flow-guiding vanes in a staggered manner, 2-4 secondary micro flow-guiding elements are evenly distributed between every two main spiral flow-guiding vanes, and the secondary micro flow-guiding elements are arranged at intervals along the circumferential direction.

[0013] Furthermore, the secondary micro-guide element is connected to the main spiral guide vane through a connecting piece, which is a T-shaped slot structure. Corresponding T-shaped protrusions are provided at both ends of the arc-shaped substrate, and the T-shaped protrusions are inserted into the T-shaped slots reserved on the main spiral guide vane assembly by sliding.

[0014] Furthermore, the partition baffle is a circular metal plate, the outer diameter of which matches the inner diameter of the cylindrical shell, and is welded and fixed to the inner wall of the cylindrical shell through an annular weld. A plurality of holes are provided on the partition baffle for the heat exchange tube bundle to pass through, and the heat exchange tube bundle is sealed and fixed to the baffle holes.

[0015] The beneficial effects of the present invention are: The present invention forms a complex three-dimensional flow pattern through the synergistic effect of variable-pitch main spiral guide vanes, staggered secondary micro-guide elements and V-shaped micro-steering vanes, effectively solving the problem of microbial reproduction faced by shell-and-tube heat exchangers in the biopharmaceutical industry under low flow rate conditions, improving equipment operation safety and product quality, while maintaining high heat exchange efficiency and cleaning convenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a front view of an aluminum alloy tubular heat exchanger proposed by the present invention; Figure 2 The present invention Figure 1 Schematic diagram of the AA section structure; Figure 3 The present invention Figure 1 Schematic diagram of the BB cross-section structure; Figure 4 The present invention Figure 2 Schematic diagram of the connection structure between the middle main spiral guide vane and the secondary micro guide element; Figure 5 The present invention Figure 4 Schematic diagram of the structure of the secondary micro-flow guide element.

[0017] In the figure: 100, cylindrical shell; 110, traditional cavity; 120, common cavity; 130, partition baffle; 140, detachable fixing component; 210, heat exchange inlet pipe; 220, heat exchange outlet pipe; 310, shell side inlet pipe; 320, shell side outlet pipe; 400, heat exchange tube bundle; 500, V-shaped micro-steering blade; 600, main spiral guide vane; 700, secondary micro-guide element; 710, curved substrate; 720, spoiler; 730, T-shaped protrusion. DETAILED DESCRIPTION

[0018] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed solely to enable those skilled in the art to better understand and implement the subject matter described herein, and that the functions and arrangements of the elements discussed may be varied without departing from the scope of this specification. Various examples may omit, substitute, or add various processes or components as needed. In addition, features described with respect to some examples may also be combined in other examples.

[0019] like Figure 1-Figure 5 As shown, an aluminum alloy tubular heat exchanger includes a cylindrical shell 100, a heat exchange tube bundle 400 and a multi-stage gradient spiral guide system; The cylindrical shell 100 is composed of a cylindrical metal shell with closed ends. Its internal space is divided into several chambers arranged in sequence along the axial direction by multiple partition baffles 130, forming a multi-chamber structure in which traditional chambers 110 and common chambers 120 are alternately arranged.

[0020] The shell side is provided with a shell side inlet pipe 310 and a shell side outlet pipe 320, and the heat medium forms a heat medium loop between the shell side inlet pipe 310 and the shell side outlet pipe 320; The baffle 130 is a circular metal plate with an outer diameter matching the inner diameter of the cylindrical shell 100. It is welded to the inner wall of the cylindrical shell 100 via an annular weld. The baffle 130 is provided with multiple holes for the heat exchange tubes to pass through. The heat exchange tubes are sealed to the baffle holes using a tube expansion process or welding to prevent fluid leakage between the chambers.

[0021] A heat exchange tube bundle 400 arranged in parallel is disposed within the conventional cavity 110. Both ends of the heat exchange tube bundle 400 are fixedly connected to tube sheets at both ends of the cylindrical shell 100. The tube sheets are connected and sealed to the cylindrical shell 100 via flanges. Heat exchange inlet pipes 210 and heat exchange outlet pipes 220 are disposed at both ends of the heat exchange tube bundle 400. The heat exchange inlet pipes 210 and heat exchange outlet pipes 220 are connected to fluid pipelines and downstream process equipment, respectively. A multi-stage gradient spiral flow guide system is installed in the common cavity 120 .

[0022] It should be noted that the "conventional cavity 110" refers to the conventional heat exchange area in a shell and tube heat exchanger, in which the heat exchange tube bundles 400 are arranged in parallel in the cylindrical shell 100, and the fluid flows in the tube or on the shell side and exchanges heat through the tube wall.

[0023] The “common cavity 120 ” is a mixing cavity located between two conventional cavities 110 , and is used to break the fluid boundary layer and enhance the heat exchange effect.

[0024] The multi-stage gradient spiral guide system includes a main spiral guide vane 600, a secondary micro-guide element 700, and a V-shaped micro-steering vane 500. The main spiral guide vane 600 is made of stainless steel or other materials that meet biopharmaceutical requirements and is directly mounted on the inner wall of the common cavity 120 in a spiral arrangement. The main spiral guide vane 600 is a sheet-like structure that extends radially inward from the inner wall of the cylindrical shell 100. The extension length is determined according to the distribution of the heat exchange tube bundle 400 in the common cavity 120 to ensure that an appropriate gap is maintained between the main spiral guide vane 600 and the heat exchange tube bundle 400. The angle of the main spiral guide vane 600 is precisely designed to be 15-30 degrees, the width is uniformly set along the radial direction, and the thickness is 2-4 mm. The leading edge of the main spiral guide vane 600 is streamlined to reduce flow resistance, while the trailing edge is designed as a micro-vortex generating structure to promote fluid disturbance. The arrangement density of the main spiral guide vane 600 is determined according to the geometric dimensions of the common cavity 120 and flow calculations to ensure that the fluid is guided to form a controlled rotational flow.

[0025] According to an embodiment of the present application, the main spiral guide vanes 600 can also adopt a variable pitch design, wherein the spiral angle of the main spiral guide vanes 600 near the fluid inlet end is 25-30 degrees, the spiral angle of the main spiral guide vanes 600 in the middle of the common cavity 120 is 20-25 degrees, and the spiral angle of the main spiral guide vanes 600 near the fluid outlet end is 15-20 degrees, forming a pitch gradient from large to small, producing a progressive fluid acceleration effect. Multiple sets of spiral main spiral guide vanes 600 can be installed in each common cavity 120 according to the length of the cavity. Each main spiral guide vane 600 is detachably connected to the inner wall of the cylindrical shell 100 through a specially designed fixing structure, facilitating cleaning and maintenance.

[0026] The main spiral guide vane 600 is fixedly connected to the inner wall of the common cavity 120 via a removable fixing assembly 140, ensuring stability under fluid impact. The removable fixing assembly 140 comprises a slot structure evenly distributed along the inner wall of the cylindrical shell 100. A corresponding snap-fit ​​structure is provided on the wall end of the main spiral guide vane 600. This snap-fitting structure secures the guide vane 600 and facilitates removal and cleaning.

[0027] The secondary micro-flow guide element 700 is a small flow-guiding component disposed between the primary spiral guide vanes 600, used to break up micro-dead zones that may occur in the primary spiral flow. The secondary micro-flow guide element 700 comprises a curved base plate 710 and a plurality of spoilers 720 secured to the base plate. The circumferential length of the curved base plate 710 is approximately 1 / 4 to 1 / 6 of the inner circumference of the cylindrical shell 100, and the width of the curved base plate 710 is the same as the width of the base of the primary spiral guide vane 600 assembly. The plurality of spoilers 720 are arranged perpendicular to the surface of the curved base plate 710, with the spoilers 720 being approximately 1 / 3 the height of the primary spiral guide vanes 600 and having a thickness of 1-2 mm.

[0028] The secondary micro-flow guiding elements 700 are arranged in a staggered pattern on the primary spiral guide vanes 600. Two to four secondary micro-flow guiding elements 700 are evenly distributed between the end surfaces of adjacent primary spiral guide vanes 600, and the secondary micro-flow guiding elements 700 are spaced apart along the circumference. The spoilers 720 of the secondary micro-flow guiding elements 700 form an angle of 15 to 30 degrees with the flow direction of the primary spiral guide vanes 600, creating a cross-flow effect.

[0029] The secondary micro-flow guide element 700 is connected to the main spiral guide vane 600 via a connector, which is a T-shaped slot. The arc-shaped base plate 710 of the secondary micro-flow guide element 700 is provided with corresponding T-shaped protrusions 730 at both ends. The secondary micro-flow guide element 700 is inserted into the T-shaped slot reserved on the main spiral guide vane 600 assembly by sliding. It can be installed or removed without removing the main spiral guide vane 600, making it easy to clean or replace it separately.

[0030] V-shaped micro-steering blades 500 are added to the wall surface and dead angle area of ​​the common cavity 120, with an angle of 10-15 degrees to guide the fluid in the low-speed area back into the main flow channel. The V-shaped micro-steering blades 500 include a base plate and two steering blades. The two steering blades are symmetrically arranged on the base plate. The base plate is arranged on the wall surface and dead angle area of ​​the common cavity 120. The angle between the two blades is 30-60 degrees, forming a V-shaped structure, with the opening direction facing the main flow channel. In the wall area, the V-shaped micro-steering blades 500 are arranged in an array, with the arrangement direction forming an angle of 10-15 degrees with the main flow direction; in the blind spot area, the V-shaped micro-steering blades 500 are arranged along the circumference of the cylindrical shell 100, with the arrangement direction also forming an angle of 10-15 degrees with the main flow direction; According to the embodiments of the present application, the primary materials for the multi-stage gradient spiral flow guide system are as follows: Surfaces in direct contact with biopharmaceutical fluids are made of FDA-compliant 316L stainless steel or biocompatible polymers. The primary spiral flow guide vane 600 component is preferably integrally formed from 316L stainless steel, electrochemically polished to a surface roughness (Ra) of no more than 0.5 microns to minimize microbial attachment points. The secondary micro-flow guide element 700 can be injection-molded from high-strength biocompatible polymers such as polyetheretherketone (PEEK) or polysulfone (PSF), offering a temperature resistance of 100-150°C and suitability for steam sterilization. The V-shaped micro-steering blade 500 can be made of flexible materials such as medical-grade silicone or polytetrafluoroethylene (PTFE), providing sufficient rigidity and durability while maintaining a certain degree of deformability when necessary.

[0031] The assembly method of the multi-stage gradient spiral guide system adopts modular design, which is easy to install, clean and maintain.

[0032] The assembly sequence is as follows: install the V-shaped micro-deflector blade 500 at the predetermined location on the wall of the common cavity 120; then, insert the primary spiral deflector blade 600 assembly axially into the common cavity 120 and secure it via the latching slot; finally, connect the secondary micro-deflector element 700 to the primary spiral deflector blade 600 assembly via the T-shaped protrusion 730. Each component is designed with no blind spots to avoid blind spots during cleaning. When thorough cleaning is required, each component can be disassembled in reverse order for individual cleaning or replacement.

[0033] In this embodiment, three to five common cavities 120 can be disposed within the cylindrical housing 100, each of which houses the aforementioned multi-stage gradient spiral flow guide system. The flow guide system within each common cavity 120 can be fine-tuned based on its location within the heat exchanger. For example, for common cavities 120 near the inlet, the pitch of the main spiral guide vanes 600 can be appropriately increased to enhance initial mixing. For common cavities 120 near the outlet, the number of V-shaped micro-diverter vanes 500 can be increased to reduce the risk of microbial attachment at the outlet.

[0034] The steps of using this embodiment are: According to the embodiment of the present application, the steps for using the aluminum alloy tubular heat exchanger are as follows: Step 1: System connection Connect the heat exchanger to the biopharmaceutical production system in the same manner as a conventional shell-and-tube heat exchanger. Connect the shell-side inlet pipe to the heat medium (usually water or steam) pipeline, and the shell-side outlet pipe to the heat medium circuit. Connect the tube-side inlet to the biopharmaceutical fluid pipeline to be processed, and the tube-side outlet to the downstream process equipment. Sanitary fittings should be used at the connections to ensure they are secure and leak-free.

[0035] Step 2: System startup and preheating Before starting up, introduce a low-temperature heat medium to slowly heat the heat exchanger to near operating temperature to avoid mechanical damage caused by thermal stress. The recommended preheating time is 10-30 minutes, depending on the heat exchanger size and process requirements. During the preheating process, a low-flow circulation method can be used to ensure uniform heating of all parts of the heat exchanger.

[0036] Step 3: Process fluid introduction and flow regulation After preheating, the biopharmaceutical fluid is slowly introduced, initially controlled at 30%-50% of the design flow rate. This flow rate is then gradually adjusted to the design operating conditions based on temperature control requirements. For low flow rates (Reynolds number <2000), the multi-stage gradient spiral flow guide system comes into play, guiding the fluid into a complex three-dimensional flow pattern.

[0037] Step 4: Run monitoring During operation, monitor the following parameters: inlet and outlet temperatures, pressures, and flow rates on the shell and tube sides to ensure that the heat transfer effect and fluid flow state meet process requirements; the temperature distribution on the outer wall of the heat exchanger, detected by an infrared thermal imager or surface temperature sensor, to determine whether the internal fluid distribution is uniform; and the system pressure drop, observing the pressure drop change trend. An abnormal increase in pressure drop may indicate that contamination is beginning to form inside the system.

[0038] The technical effects of this embodiment are as follows: The aluminum alloy tubular heat exchanger provided in this application effectively solves the problem of microbial growth caused by insufficient fluid mixing in the heat exchanger common cavity 120 under low flow rate conditions in the biopharmaceutical industry through its innovative structural design. The specific technical effects are reflected in the following aspects: First, the design of the variable-pitch main spiral guide vane 600 leverages the principle of continuity in fluid mechanics. As the fluid passes through a channel with gradually decreasing pitch, the flow velocity naturally increases, creating a progressive fluid acceleration effect. According to the law of conservation of flow, as the cross-sectional area of ​​the pipe decreases, the flow velocity necessarily increases. Therefore, even under low overall flow conditions (Reynolds number <2000), the fluid will experience local acceleration as it passes through the variable-pitch main spiral guide vane 600, significantly increasing the local Reynolds number.

[0039] Secondly, the secondary micro-flow guide elements 700 and the main spiral guide vanes 600 combine to form a multi-scale flow structure, generating a cascading vortex system. The main spiral guide vanes 600 generate large-scale spiral flow, while the staggered secondary flow guide elements superimpose small-scale disturbances on the main flow, breaking up the micro-dead zones that may have formed. Fluid visualization experiments show that this multi-scale flow structure covers a wider flow area than a single spiral structure, reducing the potential dead zone area by approximately 85%. In particular, the turbulence effect is most significant when the secondary flow guide elements form an angle of 15-30 degrees with the main spiral guide vanes 600.

[0040] Third, the V-shaped micro-diverter blades 500, installed on walls and in blind spots, specifically target low-velocity areas often overlooked in traditional designs. The pressure differential generated by the V-shaped structure effectively redirects low-velocity fluid near the wall back into the main channel, reducing the high-risk areas for microbial attachment. Wall fluid tracing tests showed that installing the V-shaped micro-diverter blades 500 reduced fluid residence time in the wall area by approximately 75%, significantly reducing the window of opportunity for microbial growth.

[0041] Fourth, the entire system utilizes a modular, removable design, completely resolving the persistent difficulty of cleaning traditional heat exchangers. Each flow guide element can be individually disassembled and cleaned, enabling targeted treatment of difficult-to-remove microbial contamination. Cleaning efficiency tests have shown that this system's cleanability is approximately 60% higher than that of traditional, non-removable flow guide structures, significantly reducing the number of residual microorganisms after a single cleaning, meeting the stringent requirements of the biopharmaceutical industry.

[0042] It should be noted that the multi-stage gradient spiral flow diversion system of this application does not seek to completely eliminate all dead zones (which is almost impossible to achieve in engineering). Instead, it significantly reduces the dead zone area and the fluid residence time within the dead zone through reasonable structural design, keeping them below biosafety limits. Experimental data shows that after adopting this technical solution, even under extremely low flow conditions with a Reynolds number as low as 800, effective fluid mixing can be maintained within the common cavity 120, and the dead zone area is controlled to less than 5% of the total area. Moreover, the fluid renewal cycle of these small residual dead zones does not exceed 5 minutes, which is far shorter than the time required for most microorganisms to form biofilms (typically several hours to days).

[0043] Furthermore, while this application is primarily designed for low-flow conditions, the multi-stage gradient spiral flow guide system is also effective under conventional and high-flow conditions, maintaining high fluid mixing and heat transfer efficiency. Under Reynolds numbers of 5,000-10,000, the system's pressure drop increase is kept within 15%, while the heat transfer coefficient is increased by 8%-10%, resulting in overall performance superior to traditional designs.

[0044] In summary, this application forms a complex three-dimensional flow pattern through the synergistic effect of the variable pitch main spiral guide vane 600, the staggered secondary micro-guide elements 700 and the V-shaped micro-steering vane 500, effectively solving the problem of microbial reproduction faced by shell and tube heat exchangers in the biopharmaceutical industry under low flow rate conditions, improving equipment operation safety and product quality, while maintaining a high heat exchange efficiency and cleaning convenience.

[0045] The above describes the embodiments of the present invention, but the present invention is not limited to the above specific implementation methods. The above specific implementation methods are merely illustrative and not restrictive. Ordinary technicians in this field can also make many forms under the guidance of the present invention, all of which are protected by the present invention.

Claims

1. An aluminum alloy tubular heat exchanger, characterized in that: include: The cylindrical shell has an internal space divided by multiple partition baffles into several chambers arranged in sequence along the axial direction, forming a multi-chamber structure in which traditional chambers and common chambers are arranged alternately. An inlet pipe and an outlet pipe are provided on the shell side, and a heat medium forms a heat medium circuit between the inlet pipe and the outlet pipe; The heat exchange tube bundle is arranged inside the cylindrical shell and passes through the partition baffle. The two ends of the heat exchange tube bundle are respectively connected to the fluid pipeline and the downstream process equipment; The multi-stage gradient spiral guide system is installed in a common cavity and includes a main spiral guide vane, a secondary micro guide element and a V-shaped micro steering vane. The main spiral guide vane is installed on the inner wall of the common cavity, the secondary micro guide element is connected to the main spiral guide vane through a connector, and the V-shaped micro steering vane is set on the wall and dead corner area of ​​the common cavity. The three are used to form a complex three-dimensional flow pattern of the fluid.

2. An aluminum alloy tubular heat exchanger according to claim 1, characterized in that: The two ends of the heat exchange tube bundle are fixedly connected to the tube sheets at both ends of the cylindrical shell respectively, and the tube sheets are connected and sealed to the cylindrical shell through flanges.

3. An aluminum alloy tubular heat exchanger according to claim 2, characterized in that: The V-shaped micro-steering blade includes a base plate and two steering blades. The two steering blades are symmetrically arranged on the base plate. The angle between the two steering blades is 30-60 degrees. The opening direction of the V-shaped micro-steering blade is toward the main channel.

4. An aluminum alloy tubular heat exchanger according to claim 3, characterized in that: The main spiral guide vane is a sheet-like structure, extending radially inward from the inner wall of the cylindrical shell. The main spiral guide vane adopts a variable pitch design. The spiral angle of the main spiral guide vane near the fluid inlet end is 25-30 degrees, the spiral angle of the main spiral guide vane in the middle of the common cavity is 20-25 degrees, and the spiral angle of the main spiral guide vane near the fluid outlet end is 15-20 degrees, forming a pitch gradient from large to small.

5. An aluminum alloy tubular heat exchanger according to claim 4, characterized in that: The main spiral guide vane is connected to the inner wall of the common cavity through a detachable fixing component. The detachable fixing component is a slot structure evenly distributed along the circumference of the inner wall of the cylindrical shell. The wall end of the main spiral guide vane is provided with a corresponding snap structure. The main spiral guide vane and the cylindrical shell are fixed through the cooperation of the snap structure and the slot structure.

6. An aluminum alloy tubular heat exchanger according to claim 5, characterized in that: The secondary micro-flow guide element includes an arc-shaped substrate and a plurality of spoilers fixed on the arc-shaped substrate. The length of the arc-shaped substrate in the circumferential direction is approximately 1 / 4 to 1 / 6 of the inner circumference of the cylindrical shell. The plurality of spoilers are arranged perpendicular to the surface of the arc-shaped substrate. The height of the spoilers is 1 / 3 of the height of the main spiral guide vanes.

7. An aluminum alloy tubular heat exchanger according to claim 6, characterized in that: The spoiler direction of the secondary micro-flow guide element and the guide direction of the main spiral guide vane form an angle of 15-30 degrees.

8. An aluminum alloy tubular heat exchanger according to claim 7, characterized in that: The secondary micro flow-guiding elements are arranged on the main spiral guide vanes in a staggered manner. 2-4 secondary micro flow-guiding elements are evenly distributed between the end surfaces of the sheet structure of the main spiral guide vanes. The secondary micro flow-guiding elements are arranged at intervals along the circumferential direction.

9. An aluminum alloy tubular heat exchanger according to claim 8, characterized in that: The connecting piece is a T-shaped slot structure, and corresponding T-shaped protrusions are provided at both ends of the arc-shaped base plate. The T-shaped protrusions are inserted into the T-shaped slots reserved on the main spiral guide vane assembly by sliding.

10. An aluminum alloy tubular heat exchanger according to claim 9, characterized in that: The partition baffle is a circular metal plate. The outer diameter of the circular metal plate matches the inner diameter of the cylindrical shell. It is welded and fixed to the inner wall of the cylindrical shell through an annular weld. There are multiple holes on the partition baffle for the heat exchange tube bundle to pass through. The heat exchange tube bundle and the baffle holes are sealed and fixed.

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