Super-hydrophobic fin-shaped condenser pipe based on porous memory alloy and preparation method of super-hydrophobic fin-shaped condenser pipe

Abstract

The invention discloses a super-hydrophobic fin-shaped condensation pipe based on porous memory alloy, and belongs to the field of condensation and heat and mass transfer enhancement. Aiming at the problems of large liquid film thermal resistance, low efficiency and poor working condition adaptability during condensation heat transfer outside a traditional condensation pipe, the invention comprises a fin-shaped condensation pipe, a porous memory alloy and a super-hydrophobic preparation method. The fin-shaped condensation pipe is made of high-heat-conduction metal, preferably red copper or aluminum, and an array type fin-shaped structure is formed through laser processing. The Ni-Ti porous memory alloy is attached to the outer side of the fin shape through SLM, and spontaneous separation of liquid drops is achieved; the super-hydrophobic characteristic provides high-density nucleation points, and rapid generation of micro-nano liquid drops is promoted. Through collaborative innovation of the super-hydrophobic fin-shaped structure, the porous memory alloy and the super-hydrophobic characteristic, the liquid drop separation critical radius can be effectively reduced, the surface renewal rate is increased, efficient and stable condensation heat transfer efficiency is achieved, and the super-hydrophobic fin-shaped structure is suitable for different condensation working conditions.

Description

Technical Field

[0001] The present invention belongs to the field of condensation and enhanced heat and mass transfer, and particularly relates to a superhydrophobic finned condensation tube based on porous memory alloy and a preparation method thereof. Background Art

[0002] As a core component in heat exchange equipment, the heat transfer performance of the condensation tube directly affects the energy efficiency ratio and operation stability of the system. During the condensation process, liquid droplets gather and discharge on the outer surface of the tube due to the temperature being lower than the dew point of the condensate. However, traditional condensation tube materials such as copper and stainless steel have hydrophilic or neutral surfaces, and liquid droplets are prone to spread into liquid films, resulting in filmwise condensation, which greatly reduces the condensation heat transfer efficiency.

[0003] To improve the condensation efficiency, existing research has introduced superhydrophobic coatings on the surface of the condensation tube to form a "dropwise condensation" mode, enabling condensate droplets to roll off quickly and reducing the attachment of liquid films, thereby improving the heat transfer performance. However, the existing superhydrophobic surface treatment methods such as chemical etching, plasma spraying, or nano-coatings have the following main deficiencies:

[0004] 1. Poor durability: After long-term operation or repeated thermal cycles, the coating is prone to wear and peeling, resulting in the loss of superhydrophobicity.

[0005] 2. Complex processing and high cost: The multi-step surface micro-nano processing technology limits its large-scale industrial application.

[0006] 3. Limited heat transfer enhancement: Although the surface coating improves the condensate discharge efficiency, the improvement in heat transfer performance is limited, especially at high heat fluxes where the thermal resistance is still large.

[0007] 4. Single structure and lack of intelligent response characteristics: Traditional condensation tubes are mostly metal smooth tubes or single fin structures, and cannot adjust the structure or performance according to different condensation conditions.

[0008] Therefore, there is an urgent need for a new type of condensation tube structure with superhydrophobicity, high heat transfer performance, and structural responsiveness to solve the above problems and improve the overall performance and reliability of the condenser. Summary of the Invention

[0009] The purpose of the present invention is to solve the problems of large liquid film thermal resistance, limited heat transfer effect, and unstable superhydrophobic performance existing in traditional condensation tubes, and to provide a superhydrophobic finned condensation tube based on porous memory alloy and a preparation method thereof, which can improve the condensation heat transfer efficiency and enhance the adaptability and reliability of the condensation tube under different working conditions.

[0010] To solve the above technical problems, the technical method adopted by the present invention is as follows: The present invention discloses a superhydrophobic finned condensation tube based on porous memory alloy, which includes a hollow main body tube made of metal material. A plurality of fin-shaped fins are arranged on the outer end surface of the hollow main body tube, and a porous memory alloy layer is arranged on the superhydrophobic fin-shaped fins;

[0011] The fin-shaped fins are subjected to superhydrophobic treatment, and the surface of the fin-shaped fins has superhydrophobic performance.

[0012] Further, the bottoms of two adjacent fin-shaped fins are connected, and the included angle between two adjacent sides is an acute angle.

[0013] Further, the hollow main body tube is made of a high thermal conductivity metal.

[0014] Further, the fin-shaped fins are distributed in an array on the outer end surface of the hollow main body tube, and the cross-section is trapezoidal; the contact surface of the fin-shaped fins and the hollow main body tube is the lower bottom surface. The length of the lower bottom surface of the fin-shaped fins is 1.5 - 2.0 mm, the height is 0.6 - 1 mm, and the length of the upper bottom surface of the fin is 0.1 - 0.3 mm.

[0015] Further, the diameter of the hollow main body tube is 6.35 mm, and the wall thickness is 1 mm.

[0016] Further, the porous memory alloy layer is made of Ti-Ni alloy, the pore diameter is 100 - 300 μm, and the porosity is 40% - 60%.

[0017] The present invention also discloses a preparation method of a superhydrophobic finned condensation tube based on porous memory alloy, which includes selecting a hollow main body tube made of metal material, processing a plurality of fin-shaped fins on the outer end surface of the hollow main body tube, and after subjecting the fin-shaped fins to superhydrophobic treatment, attaching a porous memory alloy layer on the outer surface of the fin-shaped fins.

[0018] Further, the superhydrophobic treatment includes the following steps:

[0019] S1. Immerse the finned condensation tube in a hot (90 ± 3 °C) alkaline solution composed of NaClO2, NaOH, Na3PO4·12H2O and deionized water (mass fraction of 3.75:5:10:100) to form a nano-structured copper oxide film on the cleaned finned condensation tube;

[0020] S2. Adopt the gas-phase deposition method. Place a 10 ml toluene solution of 5% volume fraction of heptadecafluorodecyltrimethoxysilane in a constant-temperature sealed reaction kettle at 80 °C. Put the sample obtained in step S1 into it and react for 3 h to construct a low surface energy molecular layer on the nano-structure surface to form a superhydrophobic interface.

[0021] Further, the preparation steps of the porous memory alloy layer are as follows:

[0022] Sa1. Establish a porous memory alloy model using 3D modeling software. Then, use specialized slicing software for selective laser melting to cut the 3D model into a series of 2D slices, generating a laser scanning path and process parameter files. Select Ni-Ti alloy powder with shape memory effect, and control its particle size within 15 - 53μm. Dry the powder to improve its fluidity and laser absorption. At the same time, perform appropriate ball milling on the powder to improve the particle size distribution and surface morphology.

[0023] Sa2. Adjust the phase transition temperature by changing the Ni content in the Ni-Ti powder to make it consistent with the condensation temperature, achieving the best condensation effect.

[0024] Sa3. Set appropriate laser parameters. Under high-purity nitrogen, prepare according to the size of the superhydrophobic finned condenser tube. When spreading a layer of powder, the laser beam scans and melts the powder according to the preset parameters to form the current layer. After each layer is completed, the platform descends by one layer thickness. Repeat powder spreading, scanning, and monitoring until the required porous memory alloy is constructed.

[0025] Further, in the step Sa2, the laser parameters include: laser power 100 - 220W, scanning speed 900 - 1100mm / s, layer thickness 40μm, and scanning spacing 100μm.

[0026] Beneficial effects:

[0027] Compared with the prior art, the innovative coupling of the superhydrophobic finned structure and the porous memory alloy in the present invention provides a high-density nucleation point for steam by the superhydrophobic finned structure, promoting the rapid generation of micron-sized droplets.

[0028] The porous memory alloy layer adsorbs the tiny droplets on the superhydrophobic fins through capillary suction effect, and ejects the droplets from the surface through the directional mechanical stress provided by the Ti-Ni shape memory effect, effectively reducing the critical radius of droplet detachment and greatly improving the droplet detachment efficiency.

[0029] Among them, the porous memory alloy has temperature-sensitive characteristics, and can achieve self-adaptive regulation of the porosity of the porous alloy and drive the structure to expand under different working temperatures and working conditions, realizing the directional bounce of droplets and avoiding the formation of liquid films, greatly improving the surface renewal rate. Description of the drawings

[0030] Figure 1 It is the overall structure schematic diagram of the superhydrophobic finned condenser tube based on porous memory alloy in the present invention;

[0031] Figure 2 It is the structure schematic diagram of the porous memory alloy layer in the present invention;

[0032] Figure 3 SEM images and contact angles of the micro-nano structures on the surface of the superhydrophobic condensing tube in the present invention;

[0033] Figure 4 Optical microscopy snapshots of the dynamic behavior of the condensate droplets on different condensing tubes in the invention;

[0034] Figure 5 Graphs showing the variation of the maximum diameter and average diameter of the condensate droplets with time on different condensing tubes in the invention. Detailed implementation manners

[0035] The following further describes multiple embodiments of the present invention with reference to the accompanying drawings. It should be understood that this is an illustrative example of the preferred implementation manners of the present invention, rather than a limitation on the protection scope of the present invention. Those skilled in the art can make various substitutions or modifications without departing from the spirit and essence of the present invention, and these substitutions or modifications shall all fall within the protection scope of the present invention.

[0036] Embodiment 1 Superhydrophobic finned condensing tube based on porous shape memory alloy.

[0037] As Figure 1 shown, a superhydrophobic finned condensing tube based on porous shape memory alloy includes a hollow main tube 1 made of metal. A number of finned fins 2 are provided on the outer end face of the hollow main tube 1, and a porous shape memory alloy layer 3 is provided on the superhydrophobic finned fins 2; the finned fins 2 are treated with superhydrophobic treatment, and the surface of the finned fins 2 has superhydrophobic properties, showing a high contact angle and a low rolling angle when contacting the condensate.

[0038] Preferably, the hollow main tube 1 is made of a metal material with good thermal conductivity, such as red copper or aluminum. Preferably, the pipe diameter is 6.35 mm, the wall thickness is 1 mm, and the length can be selected between 0.2 m and 2 m according to actual application requirements to meet the needs of different heat exchange scenarios.

[0039] Preferably, the finned fins 2 are processed into a finned structure on the outside of the copper tube by mechanical processing or precision casting. Preferably, the length of the lower bottom surface of the finned fins 2 is 1.5 - 2.0 mm, the height is 0.6 - 1.0 mm, and the length of the upper bottom surface is 0.1 - 0.3 mm. This size design can improve the hydrophobic effect and drainage efficiency without significantly increasing the volume of the condensing tube.

[0040] Further preferably, the height of the finned structure is 0.8 mm, the upper fin is 0.2 mm, and the lower fin is 1.8 mm, with a micron-level structure to ensure better condensation effect;

[0041] The cooling water inlet 4 and the cooling water outlet 5 can use working fluids such as deionized water or absolute ethanol;

[0042] Preferably, the porous shape memory alloy 2 has a shape memory effect and undergoes a phase change process from martensite to austenite when reaching a specific phase change temperature, and is a material composed of two or more metal elements; more preferably, the porous shape memory alloy 2 can be set as a titanium-nickel alloy, a gold-cadmium alloy or a copper-zinc alloy. The pore diameter of the porous shape memory alloy layer 3 is controlled within 100 - 300 μm, and the porosity is 40% - 60%, which helps to achieve the aggregation and rapid sliding of the condensate on the surface, thereby enhancing the drainage performance.

[0043] In summary, steam forms condensate droplets on the surface of the superhydrophobic finned condensing tube. The condensate droplets gradually nucleate and grow until they contact the upper porous shape memory alloy layer 3, are inhaled and converge into the upper porous shape memory alloy structure under the action of its capillary force, and then the porous shape memory alloy expands under the influence of temperature and bounces the droplets away, effectively improving the surface renewal rate and enhancing the condensation heat transfer.

[0044] In the present invention, a porous shape memory alloy layer 3 is attached to the surface of the superhydrophobic fin 2 to construct a heterogeneous interface structure with a capillary structure and microscopic disturbance ability. During the condensation process, when the condensate forms a liquid film on the fin surface, the porous shape memory alloy layer can continuously disturb the condensate liquid film and effectively reduce the liquid film thickness by virtue of its three-dimensional porous channel structure. At the same time, its capillary pumping ability can prompt the condensate to quickly detach from the hot surface, realizing the rapid renewal of the liquid film and significantly reducing the formation of the thermal resistance layer. Through the above structural design, the heat flux density and heat transfer coefficient of the condensation surface are significantly improved, and compared with the traditional condensing tube, the heat transfer efficiency can be increased by more than 20%.

[0045] The Ni-Ti porous shape memory alloy layer 3 adopted in the present invention has a unique temperature sensitivity, and its phase change behavior can dynamically adjust the material morphology according to the operating temperature of the condenser. In a typical heat pump operating environment, when the external temperature changes, the Ni-Ti alloy undergoes a martensite-austenite phase change, resulting in the microscopic reconstruction of the pore structure size and morphology, and then adjusting the surface hydrophilic-hydrophobic balance and enhancing the droplet bouncing or detachment ability. Especially under low-temperature and high-humidity conditions, this adaptive regulation mechanism can effectively inhibit the liquid film expansion, promote the rapid generation and departure of the condensate from the heat transfer surface, thereby continuously maintaining the high-efficiency condensation heat transfer ability, enhancing the system's working condition adaptability in complex climates, extending the defrosting interval, and improving the system COP performance.

[0046] The present invention innovatively integrates the super-hydrophobic fin structure 2 with the porous memory alloy layer 3 to form a coupled enhanced condensation heat exchange interface. The super-hydrophobic fin-shaped fin provides a high-density nucleation site to promote the rapid generation of nano-micron droplets on the fin surface; and the porous Ti-Ni memory alloy layer attached to the surface quickly adsorbs the droplets through its capillary guidance, and exerts a micro-mechanical ejection force on the droplets by means of the shape memory stress effect of the material, so that the droplets can be ejected from the condensation surface in a directional manner. This synergistic mechanism can not only significantly reduce the critical radius of droplet detachment and improve the droplet detachment efficiency, but also effectively prevent the "water hanging" phenomenon on the fin caused by the accumulation of condensed water, further reducing thermal resistance and improving heat exchange stability.

[0047] Example 2: Preparation method of super hydrophobic fin condenser

[0048] The super-hydrophobic properties of the super-hydrophobic finned condenser in Example 1 are prepared by chemical etching and vapor deposition, and the preparation method is as follows:

[0049] 1 Preparation of CuO nanostructures: The finned condenser tube was immersed in a hot (90±3°C) alkaline solution consisting of NaClO2, NaOH, Na3PO4·12H2O and deionized water (mass fraction of 3.75:5:10:100) to generate a nanostructured copper oxide (CuO) film on the cleaned finned condenser tube;

[0050] 2 Silane deposition benchmark super-hydrophobic surface: Using the vapor deposition method, 10 ml toluene solution of 5% volume fraction of heptadecafluorodecyltrimethylsilane was placed in a constant temperature and sealed reactor at 80°C, and the sample obtained in step 1 was placed therein to react for 3 hours, thereby constructing a low surface energy molecular layer on the surface of the nanostructure to form a super-hydrophobic interface.

[0051] The surface structure formed by this treatment method works synergistically with chemical modification to significantly increase the droplet sliding speed and effectively prevent condensate from being retained.

[0052] Figure 3 The microscopic morphology of the superhydrophobic nanostructure is shown. The outer wall of the surface-treated superhydrophobic fin-shaped copper tube presents a typical hierarchical micro-nano composite structure. The substrate is composed of micron-sized fins, and its surface further grows into a high-density nanolayer array. Adjacent nanosheet layers are arranged alternately at an angle of about 60° to form triangular structural units. The solid-liquid contact area is significantly reduced, thereby ensuring the superhydrophobicity of the copper tube surface. In addition, the apparent contact angle of the droplet on the superhydrophobic fin-shaped copper tube can reach 163.6±2.0°.

[0053] Example 3 Super-hydrophobic treatment method

[0054] like Figure 2As shown, the porous memory alloy 2 in Example 1 can be made of a titanium-nickel alloy having temperature response characteristics, and the specific preparation steps are as follows:

[0055] 1. Use 3D modeling software to build a porous memory alloy model, and then use the special slicing software for selective laser melting to cut the 3D model into a series of 2D slices to generate laser scanning paths and process parameter files. Select Ni-Ti alloy powder with shape memory effect, and its particles are controlled at 15-53μm. Dry the powder to improve the fluidity and laser absorption of the powder; at the same time, perform appropriate ball milling on the powder to improve the particle size distribution and surface morphology of the powder;

[0056] 2. By changing the Ni content in the Ni-Ti powder, the phase change temperature is adjusted to be consistent with the condensation temperature to achieve the best condensation effect;

[0057] 3 Set appropriate laser parameters: laser power 100-220W, scanning speed 900-1100mm / s, layer thickness 40μm, scanning spacing 100μm, and prepare according to the size of the superhydrophobic fin condenser under high-purity nitrogen. When spreading a layer of powder for printing, the laser beam scans the melted powder according to the preset parameters to form the current layer. After each layer is completed, the platform drops one layer thickness, and repeats powder spreading, scanning, and monitoring until the required porous memory alloy is constructed.

[0058] This porous structure, combined with its shape memory function, can undergo microscopic morphology adjustments when the temperature changes, thereby assisting droplets to detach from the surface and improving drainage efficiency and heat transfer performance.

[0059] Figure 4 The dynamic evolution behavior of condensation droplets on three different condensation tubes is shown.

[0060] like Figure 4 -a On a smooth hydrophobic tube, condensate droplets randomly nucleate and grow freely, merging into larger droplets.

[0061] like Figure 4 -b For the nanostructured superhydrophobic smooth tube, multiple droplets (n≥2) can successfully jump off the surface after merging under low supercooling, and the diameter of the bouncing droplets is between 108.6 and 217.2 μm.

[0062] from Figure 4 From the droplet size distribution on the fin-shaped superhydrophobic condenser based on porous memory alloy in -c, it can be seen that the average diameter of its droplets is significantly smaller than that of the nanosmooth tube, and the maximum and minimum droplet diameters are 119.0μm and 3.5μm.

[0063] also, Figure 5The maximum droplet diameter and average droplet diameter of condensate droplets on different condenser tubes are also shown, further indicating that the superhydrophobic finned condenser tube significantly reduces the critical radius of droplet detachment, improves the surface renewal rate, and thus greatly enhances the condensation heat transfer efficiency.

[0064] Example 4 Specific application of the condenser of the present invention in a typical heat pump air-conditioning system

[0065] This example demonstrates the specific application method of the condenser of the present invention in a typical heat pump air-conditioning system. Among them, the heat pump system includes basic components such as a compressor, a condenser, an expansion valve, and an evaporator, and the refrigerant circulates in a closed loop to complete the heat exchange process. The condenser is internally provided with a superhydrophobic finned condenser tube, such as in Examples 1 to 3. The superhydrophobic finned condenser tube based on porous shape memory alloy serves as the core structure of the outdoor heat exchanger condenser tube in the system, replacing traditional smooth copper tubes or ordinary aluminum fin tubes, and significantly improving the condensation heat transfer performance.

[0066] Specifically, the hollow main tube 1 is made of a high thermal conductivity metal material, and a high-temperature and high-pressure refrigerant such as R410A is introduced into it to complete the phase change heat release process from gaseous to liquid in the condenser. A number of fin-shaped fins 2 distributed in an array outside the hollow main tube 1 significantly increase the heat exchange area. After the fin-shaped fins 2 are treated with superhydrophobicity, gas condenses on their surfaces to form droplet-shaped droplets and easily slides off, which can effectively reduce the retention of condensed water and prevent the phenomenon of "water hanging" on the fin surfaces, and improve the heat transfer interface efficiency.

[0067] Furthermore, the porous shape memory alloy layer 3 attached to the outside of the fin-shaped fins 2, such as Ti-Ni alloy, not only has good thermal conductivity, but also has capillary driving ability due to its porous structure, can guide the condensed liquid to quickly drain out of the condensation area, and at the same time has the ability to undergo a phase change with temperature change, so that when the external environment undergoes a thermal change, its surface microstructure morphology can be automatically adjusted to optimize the dynamic heat transfer efficiency. For example, when the ambient temperature drops, the Ni-Ti alloy undergoes a martensitic phase change, and the surface micro-nano structure changes accordingly, further enhancing the superhydrophobic effect and the ability of condensed water to quickly desorb.

[0068] Under the refrigeration condition, the refrigerant enters the condenser in a high-temperature and high-pressure state after being compressed, and through the synergistic effect of the above-mentioned superhydrophobic finned structure and porous alloy, the condensation process is quickly completed, significantly improving the heat flux density of the condenser. Under the heating condition, the heat exchange direction of the system is switched, and the structure of the present invention can still play its function of enhancing bidirectional heat transfer, especially suitable for application scenarios with high frost risk under low temperature and high humidity in winter.

[0069] Actual measurements show that compared with the traditional condenser structure, the condensation efficiency per unit heat transfer area of the condenser of the present invention is increased by about 28% under the working condition of an ambient temperature of 5°C and a humidity of 80%, and the defrosting cycle is extended by about 30%, significantly improving the overall energy efficiency ratio COP of the system.

[0070] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A super hydrophobic fin condenser tube based on porous memory alloy, characterized in that: It comprises a hollow main body tube (1) made of metal material, wherein the outer end surface of the hollow main body tube (1) is provided with a plurality of fin-shaped fins (2), and the super-hydrophobic fin-shaped fins (2) are provided with a porous memory alloy layer (3); The fin-shaped fin (2) has been subjected to super-hydrophobic treatment, and the surface of the fin-shaped fin (2) has super-hydrophobic properties.

2. The super hydrophobic finned condenser tube based on porous memory alloy according to claim 1, characterized in that: The bottom ends of two adjacent fin-shaped fins (2) are connected, and the angle between two adjacent sides is an acute angle.

3. The super hydrophobic finned condenser based on porous memory alloy according to claim 1, characterized in that: The hollow main body tube (1) is made of high thermal conductivity metal.

4. The super hydrophobic fin condenser based on porous memory alloy according to claim 1, characterized in that: The fin-shaped fins (2) are distributed in an array on the outer end surface of the hollow main body tube (1) and have a trapezoidal cross-section; the contact surface between the fin-shaped fins (2) and the hollow main body tube (1) is the lower bottom surface, the length of the lower bottom surface of the fin-shaped fins (2) is 1.5-2.0 mm, the height is 0.6-1 mm, and the length of the fin-shaped upper bottom surface is 0.1-0.3 mm.

5. The super hydrophobic finned condenser tube based on porous memory alloy according to claim 4, characterized in that: The hollow main body tube (1) has a diameter of 6.35 mm and a wall thickness of 1 mm.

6. The super hydrophobic finned condenser tube based on porous memory alloy according to claim 1, characterized in that: The porous memory alloy layer (3) is made of Ti-Ni alloy, has a pore diameter of 100-300 μm, and a porosity of 40%-60%.

7. A method for preparing a super-hydrophobic fin-shaped condenser tube based on porous memory alloy, characterized in that: The method comprises selecting a hollow main body tube (1) made of a metal material, processing a plurality of fin-shaped fins (2) on the outer end surface of the hollow main body tube (1), subjecting the fin-shaped fins (2) to a super-hydrophobic treatment, and then attaching a porous memory alloy layer (3) to the outer surface of the fin-shaped fins (2).

8. The method for preparing a super-hydrophobic fin-shaped condenser tube based on porous memory alloy according to claim 7, characterized in that: The super-hydrophobic treatment comprises the following steps: S1. Immersing the fin condenser tube in a hot (90±3℃) alkaline solution consisting of NaClO2, NaOH, Na3PO4·12H2O and deionized water (mass fraction of 3.75:5:10:100) to form a nanostructured copper oxide film on the cleaned fin condenser tube; S2. Using the vapor deposition method, 10 ml of toluene solution of 5% by volume heptafluorodecyltrimethylsilane is placed in a constant temperature sealed reactor at 80°C, and the sample obtained in step S1 is placed therein to react for 3 hours, thereby constructing a low surface energy molecular layer on the surface of the nanostructure to form a superhydrophobic interface.

9. The method for preparing a super-hydrophobic fin-shaped condenser tube based on porous memory alloy according to claim 7, characterized in that: The porous memory alloy layer (3) comprises the following preparation steps: Sa1. Use 3D modeling software to build a porous memory alloy model, and then use the special slicing software for selective laser melting to cut the 3D model into a series of 2D slices to generate laser scanning paths and process parameter files; select Ni-Ti alloy powder with shape memory effect, and its particles are controlled at 15-53μm; dry the powder to improve the fluidity and laser absorption of the powder; at the same time, perform appropriate ball milling on the powder to improve the particle size distribution and surface morphology of the powder; Sa2. The phase transition temperature is adjusted by changing the Ni content in the Ni-Ti powder to make it consistent with the condensation temperature to achieve the best condensation effect; Sa3. Set appropriate laser parameters and prepare the super-hydrophobic fin condenser according to the size of the condenser under high-purity nitrogen. When spreading a layer of powder for printing, the laser beam scans the melted powder according to the preset parameters to form the current layer. After each layer is completed, the platform drops one layer thickness, and the powder spreading, scanning, and monitoring are repeated until the desired porous memory alloy is constructed.

10. The method for preparing a super-hydrophobic fin-shaped condenser tube based on a porous memory alloy according to claim 9, characterized in that: In the step Sa2, the laser parameters include: laser power 100-220 W, scanning speed 900-1100 mm / s, layer thickness 40 μm, and scanning spacing 100 μm.

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