Heat exchanger based on additive manufacturing

Abstract

The invention discloses a heat exchanger based on additive manufacturing. Comprising a radiator core body (1) made of silicon carbide in an additive manufacturing mode and a support (2) used for supporting the radiator core body (1) and made of aluminum alloy in an additive manufacturing mode. The durability and safety of the support can be improved, the service life of the whole device can be prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchange of high temperature resistant heterogeneous materials, and in particular relates to a heat exchanger based on additive manufacturing. Background Art

[0002] With the development of aviation technology, the demand for ultra-high temperature heat exchangers in aircraft and engines continues to increase. In aerospace engines, ultra-high temperature heat exchangers are used to cool key components such as turbine blades, compressors and combustion chambers. They reduce the temperature of these components through the circulation of coolants (such as fuel, lubricating oil or air) to ensure stable operation of the engine at high temperatures. In turbochargers, heat exchangers are used to cool compressed air and increase its density, thereby providing more oxygen for engine combustion. In exhaust systems, ultra-high temperature heat exchangers can be used to adjust the temperature of the exhaust system to prevent excessive heat from damaging the aircraft structure. They also help reduce infrared rays and improve stealth performance. These areas require heat exchanger products to withstand temperatures above 800°C for a long time. However, in extreme working environments, such as high temperature, high pressure and vibration, traditional heat exchange devices often have problems such as thermal stress, material fatigue and structural damage. The original aluminum alloy heat exchanger has a use temperature of no more than 250°C, stainless steel heat exchangers can only be used up to 700°C, and high-temperature alloys can be used up to 1000°C, but the density of high-temperature alloys is 8.25g / cm 2 , causing the weight of the heat exchanger product to increase by 2 to 3 times, increasing the overall gravity of the aircraft and reducing the aircraft's maneuverability. Summary of the invention

[0003] The purpose of the present invention is to provide a heat exchanger based on additive manufacturing, which can improve the durability and safety of the bracket, extend the service life of the entire device, and reduce maintenance costs.

[0004] The technical solution of the present invention is: a heat exchanger based on additive manufacturing, including a radiator core made of silicon carbide additive material and a bracket made of aluminum alloy additive material for supporting the radiator core.

[0005] In the aforementioned heat exchanger based on additive manufacturing, the connection between the bracket and the radiator core is provided with an inwardly concave honeycomb negative Poisson's ratio structure layer made of aluminum alloy additive manufacturing.

[0006] In the aforementioned heat exchanger based on additive manufacturing, the thickness of the concave honeycomb negative Poisson's ratio structure layer is 5 to 7 mm.

[0007] In the aforementioned heat exchanger based on additive manufacturing, a regular hexagonal honeycomb structure layer is provided on the outer side of the concave honeycomb negative Poisson's ratio structure layer in the bracket.

[0008] In the aforementioned heat exchanger based on additive manufacturing, the thickness of the regular hexagonal honeycomb structure layer is 13 to 14 mm.

[0009] In the aforementioned heat exchanger based on additive manufacturing, the honeycomb pores of the regular hexagonal honeycomb structure layer are filled with gel-like microcapsule repair material.

[0010] In the aforementioned heat exchanger based on additive manufacturing, the repair material has an easily identifiable color.

[0011] In the aforementioned heat exchanger based on additive manufacturing, connecting holes are provided between the negative Poisson's ratio structure layer and the honeycomb structure layer on the bracket.

[0012] The advantages of the present invention are: the present invention aims to provide a self-repairing, high-temperature resistant heterogeneous material self-detection heat exchange device, which adopts a combination of silicon carbide material and aluminum alloy material, and connects the two through additive manufacturing technology, which effectively solves the problems existing in the heat exchange device in the prior art, improves the durability and safety of the bracket, and also extends the service life of the entire device and reduces maintenance costs.

[0013] The actual weight of the product of the present invention is reduced by more than 60%; the negative Poisson's ratio structure of the concave honeycomb is added to improve the vibration resistance of the product and increase the product life from 2000h to more than 3500h. The repair material is added with easy-to-identify colors, which can remind ground staff when defects such as cracks appear, avoiding ground staff to spend time testing.

[0014] In summary, the heat exchange device of the present invention achieves stable operation at high temperatures through a unique material combination and structural design, and at the same time has self-repair and self-detection functions, which significantly improves the safety and reliability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the heat exchange device of the present invention;

[0016] Figure 2 Schematic diagram of the repairable self-test structure. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] Example 1. A heat exchanger based on additive manufacturing, see Figure 1-Figure 2 , including a radiator core 1 made of silicon carbide additive and a bracket 2 made of aluminum alloy additive for supporting the radiator core 1. High-temperature thermal fluid circulates in the inner cavity of the radiator core 1 made of silicon carbide. Silicon carbide material has the ability to withstand temperatures up to 1000°C and will not produce significant thermal stress concentration at this temperature. Its thermal conductivity exceeds that of stainless steel and high-temperature alloys, so it can effectively reduce thermal stress while enhancing the heat exchange effect. The bracket 2 is made of aluminum alloy material, which effectively reduces the potential impact of mechanical vibration on silicon carbide material; the two parts are integrated by using additive manufacturing technology to finally form a solid overall structure. The high-temperature durability of the equipment of the present invention is significantly improved, which is specifically manifested in that it can continue to operate stably in an extremely high temperature environment, and the deformation caused by thermal stress is significantly suppressed, thereby extending the service life of the equipment under ultra-high temperature conditions. The radiator core 1 of the present invention is made of silicon carbide material, and its density is 3.2g / cm 3 Compared with traditional high-temperature alloy materials (density 8.25g / cm 3 ) is significantly reduced. The lightweight effect of this material greatly reduces the overall weight of the product by more than 60%, which improves the portability of the device and reduces the restriction on engine power without affecting performance. At the same time, this also means that under the same volume, the equipment using silicon carbide material can achieve higher specific strength, providing a lighter and stronger option for applications in high temperature environments. In addition, the thermal expansion coefficient of the silicon carbide material used in the present invention is 4.4×10 -6 / ℃, thermal conductivity 60~150W / m·K, thermal expansion coefficient of stainless steel 10×10 -6~20×10 -6 / ℃, thermal conductivity is 37W / m·K. Silicon carbide material has the characteristics of low expansion rate under extreme temperature difference and high thermal conductivity, which makes it have strong thermal shock resistance when in contact with high and low temperature media. Therefore, there is no need to consider the compensation structure caused by high and low temperature shock during design, and there is no need to set up models such as expansion joints and compensation components, which reduces the complexity of the manufacturing process. At the same time, such a design also reduces the problem of mechanical stress concentration caused by temperature fluctuations, further improving the reliability and service life of the equipment.

[0021] The connection between the aforementioned bracket 2 and the radiator core 1 is provided with an inner concave honeycomb negative Poisson's ratio structural layer 3 made of aluminum alloy additive. This structure can absorb vibration energy and reduce stress concentration caused by vibration, thereby playing a shock-absorbing role. This structural design gives the present invention an additional shock-absorbing function and enhances the stability and durability of the entire heat exchange device. By adopting this structure, even under harsh working conditions, it can ensure that the connection between the silicon carbide material and the aluminum alloy bracket is firm and reliable, thereby improving the efficiency and service life of the entire heat exchange system.

[0022] The thickness of the aforementioned concave honeycomb negative Poisson's ratio structural layer 3 is 5 to 7 mm.

[0023] In the aforementioned bracket 2, a regular hexagonal honeycomb structure layer 4 is provided on the outside of the concave honeycomb negative Poisson's ratio structure layer 3. A honeycomb structure design is adopted inside the bracket. This honeycomb structure significantly reduces the weight of the bracket. At the same time, its unique porosity and elasticity can effectively absorb vibration energy from the outside or inside. The honeycomb structure has a positive Poisson's ratio structure in the center and a rigid connection point around it. In this way, the present invention further improves the shock absorption performance and enhances the stability of the entire heat exchange device. In addition, this structure also enhances the bending and torsion resistance of the bracket, so that it can still maintain structural integrity and functionality when subjected to a certain mechanical load. Therefore, the bracket design of the present invention not only achieves lightweight, but also ensures sufficient strength and durability, which helps to improve the overall efficiency and service life of the heat exchange equipment.

[0024] The thickness of the regular hexagonal honeycomb structure layer 4 is 13 to 14 mm.

[0025] The honeycomb pores of the aforementioned regular hexagonal honeycomb structure layer 4 are filled with gel-like microcapsule repair material 5. The repair material in this state can flow under the action of extrusion, so that the repair material has permeability and self-repairing properties, and can quickly penetrate into the cracks when tiny cracks appear in the bracket, thereby achieving local repair of the damaged area in a short time. This structure can not only prevent the further expansion of the cracks in time, but also help to restore the mechanical properties of the bracket, thereby extending the service life of the entire heat exchange device. Through this intelligent repair mechanism, the present invention can self-repair without external intervention, reducing maintenance costs and improving the reliability of the equipment.

[0026] The aforementioned repair material 5 has an easily recognizable color. In this way, different identification colors can be set for the repair materials in different parts according to needs. When a repair material of a certain color is squeezed out, a warning signal can be immediately sent to the user through the change of color. For example, if red repair material appears on the surface of the bracket, this indicates that the honeycomb structure at the corresponding position may have been damaged. This visual damage indication method can help users or maintenance personnel quickly identify the damaged area, so that necessary maintenance measures can be taken in time. This intelligent color coding system not only improves the safety and maintainability of the equipment, but also simplifies the fault detection process, which helps to further extend the overall service life and operating efficiency of the device.

[0027] A connecting hole 6 is provided between the negative Poisson's ratio structure layer 3 and the honeycomb structure layer 4 on the bracket 2 .

[0028] In some embodiments, hot pressing sintering or interface engineering can be used to achieve a stable connection between aluminum alloy and silicon carbide. Hot pressing sintering is to apply pressure at high temperature to bring silicon carbide and aluminum alloy close to each other and form a dense connection at the interface. Interface engineering is to improve the wettability between the two materials by designing a special interface structure, such as introducing a specific transition layer or additive, so as to promote their effective bonding at the joint.

[0029] Specifically, a layer of active metal, such as titanium, nickel or chromium, can be added to the joint of aluminum alloy and silicon carbide. These active metals can react chemically with silicon carbide and aluminum alloy during heat treatment to generate new compounds, thereby establishing a strong chemical bond between the two. This connection method not only improves the bonding strength, but also improves the fatigue performance and corrosion resistance at the interface.

[0030] In addition, for key load-bearing components such as brackets, in addition to using honeycomb structures to reduce weight, self-repairing materials can be filled inside the hollow structure. This self-repairing material can fill the cracks by itself when microcracks or damage occur in the bracket, thereby automatically repairing the damage in a short time. This self-repairing function can not only improve the durability and safety of the bracket, but also extend the service life of the entire device and reduce maintenance costs.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A heat exchanger based on additive manufacturing, characterized in that: The invention comprises a radiator core (1) made of silicon carbide additive material and a bracket (2) made of aluminum alloy additive material and used for supporting the radiator core (1).

2. The heat exchanger based on additive manufacturing according to claim 1, characterized in that: The connection between the bracket (2) and the radiator core (1) is provided with an inwardly concave honeycomb negative Poisson's ratio structural layer (3) manufactured by aluminum alloy additive manufacturing.

3. The heat exchanger based on additive manufacturing according to claim 2, characterized in that: The thickness of the concave honeycomb negative Poisson's ratio structural layer (3) is 5 to 7 mm.

4. The heat exchanger based on additive manufacturing according to claim 2, characterized in that: A regular hexagonal honeycomb structure layer (4) is provided on the outer side of the concave honeycomb negative Poisson's ratio structure layer (3) in the support (2).

5. The heat exchanger based on additive manufacturing according to claim 4, characterized in that: The thickness of the regular hexagonal honeycomb structure layer (4) is 13-14 mm.

6. The heat exchanger based on additive manufacturing according to claim 4, characterized in that: The honeycomb pores of the regular hexagonal honeycomb structure layer (4) are filled with gel-like microcapsule repairing material (5).

7. The heat exchanger based on additive manufacturing according to claim 6, characterized in that: The repair material (5) has an easily identifiable color.

8. The heat exchanger based on additive manufacturing according to claim 4, characterized in that: A connecting hole (6) is provided between the negative Poisson's ratio structure layer (3) and the honeycomb structure layer (4) on the bracket (2).

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