A heat pipe condenser section anti-particle deposition system

Abstract

The application discloses a heat pipe condensing section anti-particle deposition system and relates to the fields of energy sources including nuclear energy and mechanical equipment, and solves the technical problem of particle deposition in a heat pipe and influence on heat exchange efficiency, and the technical scheme is as follows: the main part of the heat pipe is a condensing section, further comprising an evaporating section and an adiabatic section between the condensing section and the evaporating section; a wick is arranged in the pipe body, and a working medium is filled and circulated in the pipe body. A special structure is designed on the inner and outer surfaces of the condensing section, the flow rate of the fluid can be changed, the fluid is disturbed, the fine particles in the fluid collide, the deposition rate of the fine particles is reduced, and the heat transfer outside the pipe is enhanced. The application is suitable for heat pipe systems related to energy sources including mobile small reactors, and can be widely applied to the fields of space, deep sea, medical emergency energy and the like.

Description

Technical Field

[0001] This invention belongs to the fields of energy, including nuclear energy, and mechanical equipment, and specifically relates to a system that can effectively prevent the deposition of fine particulate matter in the condensation section of a heat pipe. Background Technology

[0002] A heat pipe, invented in 1963 by Los Alamos National Laboratory in the United States, is a passive heat transfer device that uses the latent heat of vaporization to transfer heat and relies on capillary force, gravity, and centripetal force to maintain the circulation of the working fluid. It fully utilizes the principles of heat conduction and the rapid heat transfer properties of phase change media. Its characteristics include high heat transfer efficiency, high isothermal performance, strong variability, simple structure, and good environmental adaptability. From aerospace to kitchen equipment, heat pipes have a wide range of applications in heating, temperature control, cooling, heat homogenization, heat exchange, and thermal control. Small modular reactors (SMRs) use high-temperature heat pipes, specifically alkali metal heat pipes, as heat exchange devices to simplify the primary and secondary heat exchange methods, improve heat exchange efficiency, and ensure safety.

[0003] Existing research has explored the use of heat pipes as heat exchange devices in reactors, with active research and application particularly in small nuclear power plants. As early as the beginning of the 21st century, the University of New Mexico proposed applying heat pipes to space reactor power systems. During heat transfer, fine particulate matter may be present. This particulate matter can condense, deposit, and adhere to the surface of the heat exchange pipes in the working fluid, hindering heat exchange and even causing pipe corrosion, potentially leading to serious accidents and adversely affecting reactor safety. Current research largely focuses on particulate matter deposition in traditional heat exchange equipment such as finned tube, coaxial tube, and plate heat exchangers. In recent years, there has been considerable research on the performance, energy conversion, and manufacturing processes of heat pipes used in reactors, but research on fine particulate matter deposition, especially in the condensation section, of heat pipe heat exchangers is scarce.

[0004] Factors influencing fine particulate matter deposition are primarily the thermophoretic force, buoyancy, and gravity acting on particles under natural circulation conditions. The viscosity and flow velocity of the surrounding medium, the temperature difference between the medium and the wall, and the surface energy of the wall all affect the deposition rate of fine particles. Studies have shown that during particle settling, the rebound velocity of the particles is related to their elastic modulus, particle size, and the surface energy of their regular superhydrophobic surfaces. Larger particles have higher elastic moduli and lower surface energy, making them more prone to rebound and thus less likely to adhere to the surface. Therefore, improving the structure of heat pipe systems to reduce fine particulate matter deposition, especially in the condensation section, is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a heat pipe condenser section anti-particulate matter deposition system, the technical purpose of which is to effectively prevent particulate matter deposition inside the heat pipe, especially in the condenser section, thereby improving heat exchange efficiency and reducing pipe wall corrosion.

[0006] The above-mentioned technical objective of this application is achieved through the following technical solution:

[0007] A particulate matter anti-deposition system for a heat pipe condensation section is disclosed. The system is located in the condensation section of the heat pipe. The heat pipe also includes an evaporation section and an insulating section between the condensation section and the evaporation section. The outer layer of the heat pipe body is a pipe wall, and a liquid wick connected to the inner surface of the pipe wall is provided. The pipe body is filled with a circulating working fluid. The outer surface of the condensation section is provided with rounded protrusions and grooves, and an orthogonal electromagnetic field is provided outside the condensation section.

[0008] Furthermore, the superhydrophobic surface located on the outer surface of the condensation section tube wall is composed of a nano-coating on the outer surface of the condensation section tube wall. The nano-coating material is SiO2, Al, Ti, or V, and the contact angle θ of the superhydrophobic surface is >150°.

[0009] Furthermore, the height of the rounded corner protrusion is 3mm to 5mm, and the material of the rounded corner protrusion is aluminum alloy, graphene, or GH2747.

[0010] Furthermore, the groove is an annular groove parallel to the cross-section of the heat pipe, and the cross-section of the groove is rectangular, with a width of 2mm to 3mm and a depth of 1mm to 3mm.

[0011] Furthermore, the condensation section is provided with ring-shaped magnets at both the inlet and outlet, with the N pole of the magnet at the inlet facing the S pole of the magnet at the outlet; the condensation section is grounded, and the working fluid outside the heat pipe is connected to the positive electrode, forming a circuit between the condensation section and the working fluid outside the heat pipe, with the electric field direction of the circuit perpendicular to the axis of the tube.

[0012] Furthermore, the insulation section, the condensation section, and the evaporation section are all straight pipes, and the cross-sectional area of ​​the insulation section is larger than that of the evaporation section and the condensation section.

[0013] Furthermore, the outer surface material of the pipe wall is 5A06 aluminum-magnesium alloy or graphene oxide.

[0014] Furthermore, the liquid-absorbing core has a phospholipid-like bilayer structure, which includes two layers of metal spheres connected by metal fibers.

[0015] Furthermore, the diameter of the metal sphere is 0.5 mm to 0.8 mm, and its material is aluminum alloy, graphene, or GH2747; the diameter of the metal fiber is 3 μm to 5 μm, and its material is nickel alloy.

[0016] Furthermore, the metal spheres in each layer are arranged in a hexagonal pattern and connected together, with the layer of metal spheres closest to the tube wall welded to the inner surface of the tube wall; each metal sphere is welded together with 10 to 20 metal fibers.

[0017] The beneficial effects of this application are as follows: the rounded protrusions on the outer surface of the heat pipe condensation section can turbulentize the working fluid and rebound particulate matter, while the grooves interfere with the movement and deposition of fine particulate matter by disturbing the fluid; when the magnetic field lines of the heat pipe are perpendicular to the electric field lines and parallel to the streamlines, the generated electromagnetic force is orthogonal to both the streamlines and the electric field lines, resulting in a relatively strong effect of the electromagnetic force on the fluid, producing a bidirectional stirring effect and accelerating the flow of the working fluid. This gives the entire heat pipe excellent heat transfer performance and reduces particle deposition, improving the heat exchanger's efficiency. It can be applied to similar energy systems, including small reactors, and features a simple structure and high safety. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the heat pipe for preventing particulate matter deposition as described in this application;

[0019] Figure 2 for Figure 1 AA cross-section view;

[0020] Figure 3 for Figure 1 BB cross-section;

[0021] Figure 4 for Figure 1 CC cross-section;

[0022] Figure 5 This is a schematic diagram of the axial arrangement of metal spheres;

[0023] Figure 6 This is a magnified view of a portion of the suction core structure;

[0024] Figure 7 This is a partial cross-sectional view of the groove on the outer wall of the condensation section;

[0025] In the diagram: 1-Pipe body; 2-Condensation section; 3-Insulation section; 4-Evaporation section; 5-Circuit; 6-Nano coating; 7-Magnet; 8-Liquid flow direction inside the heat pipe; 9-Gas flow direction inside the heat pipe; 10-Suction core; 11-Pipe wall; 12-Insulation sleeve; 13-Rounded corner protrusion; 14-Groove; 15-Electric field direction; 16-Magnetic field direction; 17-Metal sphere; 18-Metal fiber; 19-Working fluid inside the heat pipe; 20-Working fluid outside the heat pipe. Detailed Implementation

[0026] The technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0027] Figure 1 This is a schematic diagram of the structure of the heat pipe described in this application for preventing particulate matter deposition, particularly in the condensation section. Figure 2 The heat pipe includes a pipe body 1, and inside the pipe body 1, from left to right, there are a condensing section 2, an insulating section 3 and an evaporating section 4. The outer layer of the condensing section 2, the insulating section 3 and the evaporating section 4 is a pipe wall 11, and the inner surface of the pipe wall 11 is provided with a liquid wick 10 connected thereto.

[0028] One end of the pipe body 1 is the condensation section 2, and the other end of the pipe body 1 is the evaporation section 4. Between the condensation section 2 and the evaporation section 4 is the insulation section 3. The inner diameter of the insulation section 3 pipe is larger than the inner diameter of the evaporation section 4 pipe and the inner diameter of the condensation section 2 pipe. The cross-sectional area of ​​the insulation section 3 pipe is larger than the cross-sectional area of ​​the evaporation section 4 pipe and the cross-sectional area of ​​the condensation section 2 pipe.

[0029] The tube body 1 is filled with a circulating working fluid 19, and the type of working fluid 19 in the heat pipe is determined according to the actual temperature requirement.

[0030] The tube wall 11 is made of Inconel-690 alloy or C71500 alloy. Inconel-690 alloy has excellent resistance to intergranular corrosion and intergranular stress corrosion cracking, while high-purity C71500 alloy can resist cold deformation, hot deformation and corrosion, and is more suitable for small marine heat exchangers.

[0031] The outer surface of the pipe wall 11 in the condensation section 2 is coated with a nano-coating 6. The outer surface of the pipe wall 11 in the insulation section 3 is provided with an insulation sleeve 12. The outer surface of the pipe wall 11 in the condensation section 2 has an annular groove 14 parallel to the cross-section of the pipe body 1. The outer surface of the pipe wall 11 outside the groove 14 has rounded corner protrusions 13. Both the groove 14 and the rounded corner protrusions 13 are coated with the nano-coating 6. Figure 7 As shown.

[0032] In a specific embodiment, the height of the rounded corner protrusion 13 is 3mm to 5mm, and the material of the rounded corner protrusion 13 is aluminum alloy, Inconel-690 alloy or GH2747 alloy. The rounded corner protrusion can turbulentize the working fluid and rebound particulate matter.

[0033] In a specific embodiment, the groove 14 has a rectangular cross-section with a width of 2mm to 3mm and a depth of 1mm to 3mm. The groove disturbs the movement and deposition of fine particles by agitating the fluid.

[0034] In a specific embodiment, the nano-coating 6 is made of SiO2, Al, Ti, or V. The nano-coating 6 forms a superhydrophobic surface with a contact angle θ > 150°, exhibiting low surface energy that allows particulate matter to bounce off, preventing fine particles from adhering to the pipe surface and causing corrosion. The nano-coating utilizes a micro-nano bilayer structure achieved through laser etching technology, effectively reducing its surface energy and providing excellent anti-fouling and anti-adhesion properties, as well as superior superhydrophobic performance.

[0035] Both the inlet and outlet of the condensation section 2 are equipped with ring magnets 7. The N pole of the magnet at the inlet of the condensation section 2 is opposite to the S pole of the magnet at the outlet. The magnetic field 16 formed by the magnet 7 is parallel to the axis of the tube body 1.

[0036] The condenser section 2 is grounded, and the external working fluid is connected to the positive electrode, forming a circuit 5. The electric field direction 15 of circuit 5 is perpendicular to the axis of tube 1. Figure 4 As shown. When the magnetic field lines 16 are perpendicular to the electric field lines 15 and parallel to the streamlines (the flow direction of the working fluid inside and outside the tube 1), the generated electromagnetic force is orthogonal to both the streamlines and the electric field lines. The electromagnetic force has a relatively strong effect on the fluid, producing a bidirectional stirring effect on the fluid and accelerating the flow of the working fluid.

[0037] The circulation of the external working fluid 20 of the heat pipe, such as the flow of water, air, liquid metal, supercritical CO2, etc.

[0038] The flow of the working medium inside and outside the tube 1 of this application can be co-current, counter-current, or cross-flow in the same direction; it can be forced circulation or natural circulation.

[0039] The absorbent core 10 has a phospholipid-like bilayer structure, such as Figure 3 As shown. This phospholipid-like bilayer structure comprises two opposing, interlocking phospholipid-like molecular structures, namely two layers of metal spheres 17, which are connected by metal fibers 18. Furthermore, each metal sphere 17 is welded together with 10 to 20 metal fibers 18, as shown. Figure 6 As shown. The metal spheres 17 in each layer are arranged in a hexagonal pattern and connected together, as... Figure 5 As shown. A layer of metal spheres 17 near the pipe wall 11 is welded to the inner surface of the pipe wall 11.

[0040] In a specific embodiment, the diameter of the metal sphere 17 is 0.5 mm to 0.8 mm, and the material of the metal sphere 17 is aluminum alloy, graphene, or GH2747; the diameter of the metal fiber 18 is 3 μm to 5 μm, and the material of the metal fiber 18 is nickel alloy.

[0041] The absorbent core 10 is designed to mimic the flowability of a phospholipid bilayer (cell membrane) structure, generating slight disturbances when subjected to force. The metal fiber 18 has good thermal conductivity and corrosion resistance, and can also play a turbulence role, promoting heat conduction and reducing particulate matter deposition.

[0042] The heat pipe for preventing particulate matter deposition described in this application works as follows: after steam reaches the condensing section 2 and releases heat, it condenses into a liquid working fluid. The liquid working fluid in the condensing section 2 flows back to the evaporating section 4 under the capillary driving force generated by the wick 10, and a new cycle begins. This cycle continues, thereby efficiently transferring heat from the evaporating section 4 to the condensing section 2. External heat is absorbed by the low-temperature evaporating section 4, and internal heat is discharged to the outside of the pipe by the condensing section 2.

[0043] The above are exemplary embodiments of this application, and the scope of protection of this application is defined by the claims and their equivalents.

Claims

1. A particulate matter deposition prevention system for a heat pipe condensation section, wherein the particulate matter deposition prevention system is located in the condensation section (2) of a heat pipe, the heat pipe further includes an evaporation section (4) and an insulation section (3) between the condensation section (2) and the evaporation section (4), and the outer layer of the heat pipe body (1) is a pipe wall (11), characterized in that: The inner surface of the tube wall (11) is provided with a liquid-absorbing core (10) connected thereto. The tube body (1) is filled with a circulating heat pipe working fluid (19). The outer surface of the condensing section (2) is provided with rounded protrusions (13) and grooves (14). The outside of the condensing section (2) is provided with an orthogonal electromagnetic field. The condensing section (2) is provided with a ring-shaped magnet (7) at both the inlet and outlet. The N pole of the magnet at the inlet is opposite to the S pole of the magnet at the outlet. The magnetic field formed by the magnet (7) is parallel to the axis of the tube body (1). The condensing section (2) is grounded, and the working fluid (20) outside the heat pipe is connected to the positive electrode. The condensing section (2) and the working fluid (20) outside the heat pipe form a loop (5). The electric field direction (15) of the loop (5) is perpendicular to the axis of the tube body (1). When the magnetic field line (16) is perpendicular to the electric field line and parallel to the streamline, the generated electromagnetic force is orthogonal to the streamline and the electric field line. The streamline indicates the flow direction of the working fluid inside and outside the tube body (1).

2. The particulate matter deposition prevention system according to claim 1, characterized in that: The superhydrophobic surface located on the outer surface of the condensation section (2) is composed of a nano-coating (6) located on the outer surface of the condensation section (2) wall. The nano-coating (6) is made of SiO2, Al, Ti, or V, and the contact angle θ of the superhydrophobic surface is >150°.

3. The particulate matter deposition prevention system according to claim 1, characterized in that: The height of the rounded corner protrusion (13) is 3mm to 5mm, and the material of the rounded corner protrusion (13) is aluminum alloy, graphene, or GH2747.

4. The particulate matter deposition prevention system according to claim 1, characterized in that: The groove (14) is an annular groove parallel to the cross-section of the heat pipe. The cross-section of the groove (14) is rectangular, with a width of 2mm to 3mm and a depth of 1mm to 3mm.

5. The particulate matter deposition prevention system according to claim 1, characterized in that: The insulation section (3), the condensation section (2) and the evaporation section (4) are all straight pipes, and the cross-sectional area of ​​the insulation section (3) is larger than that of the evaporation section (4) and the condensation section (2).

6. The particulate matter deposition prevention system according to claim 1, characterized in that: The outer surface material of the pipe wall (11) is 5A06 aluminum-magnesium alloy or graphene oxide.

7. The particulate matter deposition prevention system according to claim 1, characterized in that: The liquid-absorbing core (10) has a phospholipid-like bilayer structure, which includes two metal spheres (17) connected by metal fibers (18).

8. The particulate matter deposition prevention system according to claim 7, characterized in that: The diameter of the metal sphere (17) is 0.5 mm to 0.8 mm, and its material is aluminum alloy, graphene, or GH2747; the diameter of the metal fiber (18) is 3 μm to 5 μm, and its material is nickel alloy.

9. The particulate matter deposition prevention system according to claim 7, characterized in that: The metal spheres (17) in each layer are arranged in a hexagonal pattern and connected together. The layer of metal spheres (17) closest to the tube wall (11) is welded to the inner surface of the tube wall (11). Each metal sphere (17) is welded together with 10 to 20 metal fibers (18).

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