A fluidic heat dissipating device
Patent Information
- Application Number
- CN202611375041.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-07
- Publication Date
- 2026-10-09
AI Technical Summary
但现阶段射流冲击结构面临两个问题：（1）传统的单孔冲击冷却靶面的换热特征呈现明显的“钟型”分布，即滞止点的传热系数要比远离滞止点的传热系数高得多
1.本发明提供的射流散热装置，采用矩阵式射流孔结合回流通道，实现避免回流流体继续在相邻射流之间运动，干扰冲击射流运动状态。由于多个射流孔射流撞击被冷却表面后产生的横向流会相遇并相互作用，因此，设置回流通道可在其相遇后, 使其以最短路径离开换热腔，使得横向流不进一步干扰射流运动。
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Figure CN122892166A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of heat dissipation equipment technology, and more specifically, to a jet heat dissipation device. Background Technology
[0002] With the rapid development of technology, electronic components in avionics systems are evolving towards higher frequencies, higher speeds, denser structures, and smaller sizes. This has led to increasingly prominent overheating problems for these components, necessitating the design of effective heat dissipation solutions. Heat sinks are a common heat dissipation method, but optimizing the heat dissipation of conventional standalone heat sinks has essentially reached its limit, requiring a combination of other cooling methods. Therefore, the thermal design of heat dissipation devices used in avionics systems has become an urgent problem to be solved.
[0003] Jet cooling technology is a highly efficient and economical cooling technology. Due to the short flow path and thin flow boundary layer on the impacted surface, a strong heat transfer effect is generated near the stagnation point. However, the jet impact structure currently faces two problems: (1) The heat transfer characteristics of the traditional single-hole impact cooling target surface show an obvious "bell-shaped" distribution, that is, the heat transfer coefficient at the stagnation point is much higher than that far from the stagnation point. Even if array cooling is used, many "cold spots" usually appear in the cooling area, resulting in a large temperature gradient. (2) After the jet impacts the cooled surface, the fluid velocity direction changes, forming a wall-attached jet that moves parallel to the cooled surface. The wall-attached jets generated by adjacent jets move towards each other. After meeting, they move in the opposite direction along the jet direction, forming a backflow fluid, which interferes with the motion state of the impact jet. Summary of the Invention
[0004] The purpose of this invention is to provide a jet heat dissipation device that addresses the shortcomings of existing technologies and solves the problems mentioned in the background section.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A jet heat dissipation device includes a housing with an inlet, a return outlet and a cavity. A jet plate is disposed inside the housing, and the jet plate divides the cavity into a flow distribution cavity and a heat exchange cavity. The inlet and the flow distribution cavity are connected, and external airflow enters the flow distribution cavity through the inlet. The jet plate has a plurality of jet holes arranged in a spiral structure. The flow distribution cavity and the heat exchange cavity are connected through the jet holes. The airflow forms a swirling flow through the jet holes and enters the heat exchange cavity. The jet plate has a return channel, and the return port and the heat exchange chamber are connected through the return channel. The return channel is used to guide the airflow in the heat exchange chamber to the return port.
[0006] Optionally, the bottom of the heat exchange cavity is matrix-distributed with conical structural members, which correspond to the jet holes. The conical structural members are used to change the movement path of the swirling flow and increase the heat exchange area.
[0007] Optionally, the bottom of the heat exchange cavity is matrix-distributed with heat exchange elements for increasing the heat exchange area, and the heat exchange elements are provided with heat exchange holes.
[0008] Optionally, the return channel includes a first channel and a plurality of second channels. The first channel is opened along the horizontal direction of the jet plate and is connected to the return port. The plurality of second channels are distributed in a matrix and opened along the height direction of the jet plate. One end of each row or column of the plurality of second channels is connected to the heat exchange cavity, and the other end is connected to the same first channel.
[0009] Optionally, the helix angle of the jet orifice is 30°, and the height h of the jet orifice is related to the thread pitch diameter d. j Satisfies: h=3d j ; Optionally, the distance H from the lower end of the jet hole to the bottom of the heat exchange chamber and the thread inner diameter d of the jet hole satisfy: H=5d.
[0010] Optionally, the angle of the tapered structural member is 50°, and the diameter d1 of the tapered structural member and the inner diameter d of the thread satisfy: d1=2d.
[0011] Optionally, the housing includes a cover for opening and closing the diversion chamber, and the inlet is formed on the cover.
[0012] The present invention has at least the following advantages or beneficial effects: 1. The jet cooling device provided by this invention employs a matrix of jet holes combined with a return channel to prevent the return fluid from continuing to move between adjacent jets and interfering with the motion of the impact jet. Since the transverse flows generated after multiple jet holes impact the cooled surface will meet and interact, the return channel ensures that after they meet, they leave the heat exchange chamber via the shortest path, preventing the transverse flows from further interfering with the jet motion.
[0013] 2. The jet orifice employs a spiral structure, generating swirling flow as gas passes through the spiral channels. The swirling jet impacts the target surface by superimposing a tangential velocity component on the axial velocity, influencing the flow structure and state within the jet space, thus altering the heat transfer characteristics. The addition of the swirling tangential velocity accelerates the entrainment of surrounding airflow, causing the axial jet to decay more rapidly. Since most of the jet impacting the cooling airflow is in a high-speed turbulent state, the addition of the swirling flow increases the turbulence intensity of the entire jet flow field. The rapid decay of the axial velocity and the greater turbulence intensity inevitably affect the strength and uniformity of heat transfer on the target surface. This significantly enhances the heat transfer coefficient of the target surface and improves the radial uniformity of heat transfer.
[0014] 3. By setting multiple conical structural components at the bottom of the heat exchange cavity, the surface area of the heat exchange cavity can be increased, achieving efficient heat exchange. The heat transfer area of the conical heat sink jet radiator can be divided into four parts: the free jet zone, the slanted zone, the deflection zone, and the wall jet zone. By using conical structural components, compared with the previous radiators where the jet directly impacts the base plate, the slanted zone and the deflection zone are added. The original point jet impact is changed to plate slanted impact heat exchange, which increases the heat exchange area of the jet impact surface, thereby improving the heat exchange efficiency.
[0015] 4. By setting multiple heat exchange elements at the bottom of the heat exchange chamber, and opening heat exchange holes on the heat exchange elements, heat is transferred from the bottom of the heat exchange chamber to the heat exchange elements, which not only increases the heat transfer methods, but also accelerates heat transfer by increasing the contact area with the gas. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 A schematic diagram of the jet heat dissipation device provided by the present invention; Figure 2 A schematic diagram of the internal structure of the jet heat dissipation device provided by the present invention; Figure 3 This is also a schematic diagram of the internal structure of the jet heat dissipation device provided by the present invention; Figure 4 Temperature distribution cloud maps of the heat sink jet surface and heat exchange surface provided for this invention; Figure 5 The cross-sectional velocity distribution cloud map of each row of jet holes in the heat sink provided by the present invention; Figure 6 The cross-sectional velocity distribution cloud diagram of the heat sink reflux structure provided by the present invention; Figure 7 The vector diagram of the velocity of each jet hole in the heat sink provided by this invention; Figure 8 The velocity vector diagram of the heat sink reflux structure provided by this invention; Figure 9 The heat sink velocity trace diagram provided for this invention.
[0018] Icons: 1. Inlet; 2. Return port; 3. Cavity; 4. Shell; 5. Cover; 6. Jet plate; 7. Flow divider; 8. Heat exchanger; 9. Jet orifice; 10. Return channel; 11. First channel; 12. Second channel; 13. Conical structure; 131. Free jet zone; 132. Sweep zone; 133. Bending zone; 134. Wall jet zone; 14. Heat exchanger; 15. Heat exchange hole. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0020] The embodiments of this application provide a jet heat dissipation device, which achieves cooling and heat dissipation of electronic components by attaching the bottom of the heat dissipation device to electronic components and connecting an external cooling fluid circulation device.
[0021] Please refer to Figures 1 to 3 As shown, the jet cooling device includes a housing 4 with an inlet 1, a return outlet 2, and a cavity 3. The housing 4 includes a cover 5 for opening and closing the cavity 3, and the inlet 1 is located on the cover 5. A jet plate 6 is disposed inside the housing 4, and the jet plate 6 is sealed to the periphery of the cavity 3, dividing the cavity 3 into a distribution cavity 7 and a heat exchange cavity 8. Multiple jet holes 9 in a spiral structure are distributed in a matrix on the jet plate 6. The distribution cavity 7 is located above the jet plate 6 and communicates with the inlet 1, allowing external cold air to flow into the distribution cavity 7 through the inlet 1. The heat exchange cavity 8 is located below the jet plate 6, with its bottom outer side in contact with electronic components. The heat from the electronic components is transferred to the bottom of the heat exchange cavity 8. The heat exchange cavity 8 is connected to the distribution cavity 7 through the jet holes 9, and cold air is sprayed through the jet holes 9 onto the bottom of the heat exchange cavity 8, resulting in heat transfer and thus cooling the electronic components.
[0022] Please refer to Figure 3As shown, a return channel 10 is formed within the jet plate 6. The return channel 10 includes a first channel 11 and multiple second channels 12. The first channel 11 is formed along the horizontal direction of the jet plate 6, and its end is connected to the return port 2. The multiple second channels 12 are arranged in a matrix along the height direction of the jet plate 6. One end of each row or column of multiple second channels 12 penetrates the bottom surface of the jet plate 6 and is connected to the heat exchange chamber 8, while the other end is connected to the same first channel 11. In this embodiment, the number of first channels 11 is the same as the number of rows or columns of second channels 12. After heat exchange, the cold airflow in the heat exchange chamber 8 enters the first channel 11 through the second channels 12, and then is introduced into an external cooling fluid circulation device through the return port 2.
[0023] Since this heat dissipation device uses a matrix-type jet hole 9 for jetting, the transverse flow generated by adjacent jets after impacting the bottom surface of the heat exchange cavity 8 will meet and interact. By arranging multiple second channels 12 in a matrix near the jet hole 9, the airflow after heat exchange can leave the heat exchange cavity 8 with the shortest path, so that the transverse flow will not further interfere with the jet movement.
[0024] It should be noted that, since the cooling medium of this heat dissipation device is gas, the spiral jet hole 9 should meet the following conditions: the helix angle of the jet hole 9 is 30°, and the height h of the jet hole 9 is approximately equal to the thread pitch diameter d. j Satisfies: h=3d j In h=3d j As the helix angle increases from 0° to 45°, the Nusselt number Nu at the center of the heat dissipation surface first increases and then decreases, reaching its maximum at a helix angle of 30°. Therefore, the heat transfer effect is best when the helix angle of the jet orifice is 30°. The impact distance (the distance from the lower end of the jet orifice 9 to the bottom of the heat exchange chamber 8) H and the thread inner diameter d satisfy: H = 5d. As H / d increases, the Nusselt number Nu gradually increases, reaching its maximum value at H / d = 5. When H / d > 5, the Nu value begins to decrease. This is because as H / d increases, the entrainment effect becomes more significant, causing the jet core region to continuously expand into a bell shape, thereby reducing the primary impact intensity and heat transfer effect. In this embodiment, h = 9 mm, d j =3mm, H=5mm, d=1mm, so that the airflow can be swirled when ejected from the jet hole 9.
[0025] The jet orifice 9 employs a spiral structure design, generating swirling flow of gas through the spiral channel. The swirling jet impacts the axial velocity with a superimposed tangential velocity component, thus influencing the gas flow structure and state within the heat exchange chamber 8. This causes changes in the heat transfer characteristics of the cooled surface. The addition of the swirling tangential velocity accelerates the entrainment of surrounding airflow, thereby accelerating the attenuation of the axial jet. Most of the jet impact cooling airflow is in a high-speed turbulent state; the addition of the swirling flow increases the turbulence intensity of the entire jet flow field. The rapid attenuation of the axial velocity and the high turbulence intensity inevitably affect the strength and uniformity of heat transfer on the cooled surface. This significantly enhances the heat transfer coefficient of the heat exchange target surface and improves the radial uniformity of heat transfer.
[0026] Preferably, the bottom of the heat exchange cavity 8 is matrix-distributed with conical structural members 13, which correspond to the jet holes 9. The conical structural members 13 divide the heat transfer area at the bottom of the heat exchange cavity 8 into four parts: a free jet region 131, a swept-over region 132, a deflection region 133, and a wall jet region 134. Airflow impact in the free jet region 131 disperses the airflow, thinning its edges, and flows along the swept-over region 132, deflection region 133, and wall jet region 134, increasing the heat transfer area of the jet impact surface and thus improving heat transfer efficiency. The parameters of the conical structural members 13 should satisfy the following: the angle of the conical structural member is 50°; as the angle of the conical structural member increases, the Nusselt number (Nu) increases accordingly, reaching a peak and then decreasing. This phenomenon stems from the fact that the primary impact effect in the stagnant region is stronger than the secondary impact effect in the transition region. However, due to the presence of the cone, the angle between the dimensionless velocity vector and the temperature gradient vector changes as the angle of the conical structure increases, causing the former to gradually weaken compared to the latter. When the angle of the conical structure is approximately 50°, the jet impact heat dissipation in the two regions reaches equilibrium. When A exceeds 50°, the secondary impact effect in the transition zone of the cooling system begins to dominate. The velocity variation in the secondary impact zone is smaller than that in the primary impact zone, resulting in insufficient impact and thus weakening the heat transfer capacity. Therefore, the average Nusselt number Nu reaches its peak when the angle of the conical structure is 50°. The diameter d1 of the conical structure and the inner diameter d of the thread satisfy: d1 = 2d. As d1 / d increases, the Nu value gradually rises, but decreases rapidly when d1 / d exceeds 2. As the bottom diameter of the cone increases, the contact area between the jet fluid and the bottom of the heat dissipation cavity expands, resulting in a slight increase in heat transfer efficiency. However, as d1 / d continues to increase, the jet diameter also increases, and due to the entrainment effect, the surrounding medium is drawn into the jet core region, and the stagnation zone also expands. Therefore, under the combined effects of the stagnation zone and the transition zone, the Nu value reaches its maximum at d1 / d=2, and then drops sharply. In this embodiment, d1=2mm.
[0027] The combination of the spiral jet orifice 9 and the conical structural member 13 enables the swirling flow generated by the spiral jet orifice 9 to impact the top of the conical structural member 13 and then be guided by the conical surface to form a spiral expanding downward flow with radial expansion, axial (oblique) downward, and circumferential rotation characteristics. This achieves the beneficial effect of multiple heat transfer enhancements: this flow pattern allows the high-speed airflow to closely adhere to the inclined surface of the conical structural member 13 for long-term, large-area scouring heat transfer, significantly increasing the effective heat transfer area and heat transfer time compared to the traditional vertical impact plate heat transfer method; the high turbulence intensity of the swirling flow itself, combined with the complex three-dimensional flow path of the conical surface, further enhances the flow field. Turbulence enhances the disturbance and mixing of fluid micro-particles, laying the foundation for efficient convective heat transfer. At the same time, the centrifugal effect generated by the spiral motion can throw the fluid that has absorbed heat and heated up on the surface of the conical structure 13 to the external mainstream area, and entrain the low-temperature fluid in the center to the conical surface, continuously destroying and renewing the thermal boundary layer, effectively maintaining a high heat transfer temperature difference. In addition, the matrix arrangement of the conical structure 13 and the swirling flow above it together form an orderly flow field network, which can not only uniformly diffuse the concentrated heat at the jet stagnation point, but also reduce the backflow interference between adjacent jets, greatly improving the temperature uniformity of the entire heat transfer surface, and ultimately achieving efficient cooling enhancement of the conical structure.
[0028] Preferably, heat exchange elements 14 are arranged in a matrix at the bottom of the heat exchange cavity 8. The heat exchange elements 14 are one or more of cylinders, cuboids, and polyhedra. Heat from the bottom of the heat exchange cavity 8 is transferred to the heat exchange elements 14. When the airflow passes through the heat exchange cavity 8, multiple heat exchange elements 14 exchange heat synchronously with the airflow, which increases the number of heat transfer methods and accelerates heat transfer. Heat exchange holes 15 are provided on the heat exchange elements 14, which can improve heat transfer performance and reduce pressure loss.
[0029] Please refer to Figures 4 to 9 As shown, Figure 4 (a) is a cloud map showing the temperature distribution on the heat sink jet surface. Figure 4 (b) is a cloud map showing the temperature distribution of the heat sink heat exchange surface. Figure 4 It is a temperature distribution map, which mainly shows the temperature rise and temperature distribution, with the temperature distribution being relatively uniform. Figure 5 , Figure 6 These are velocity cloud maps, representing the gas velocity inside the radiator. The redder the area, the faster the velocity. Based on these two maps, it can be seen that the gas is accelerated by the spiral structure; at the same time, it can be seen that the cone-shaped structure below plays a role in diverting the gas. Figure 7 , Figure 8 It is a velocity vector diagram, and Figure 5 , Figure 6 Similarly, this also proves the corresponding roles of spiral and conical structures. Figure 9 It is a streamline diagram. The denser the lines, the faster the speed at that point. The lines are very dense at the outlet of the recirculation structure, indicating that the gas after heat dissipation is well dissipated from that outlet.
[0030] To fully demonstrate the superiority of this embodiment, this application compares the jet heat dissipation device with heat dissipation devices in existing literature in terms of temperature rise.
[0031] This embodiment includes a numerical analysis to investigate the changes in temperature rise, critical heat flux (CHF), and pressure drop. Generally, the lower the temperature rise, the higher the heat dissipation, and the higher the critical heat flux (CHF), the better the heat transfer characteristics. Under the conditions of an inlet gas temperature of 25°C, an ambient temperature of 25°C, a heat dissipation of 60W, and a gas flow rate of 0.0023kg / s, the temperature rise of the cold plate should be controlled below 50°C.
[0032] Temperature rise and voltage drop of common heat dissipation devices
[0033] The results show that the temperature rise of the jet cooling device is significantly lower than that of the radiators in other studies.
[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A jet heat dissipation device, characterized in that, The device includes a housing with an inlet, a return outlet, and a cavity. A jet plate is provided inside the housing, which divides the cavity into a flow distribution cavity and a heat exchange cavity. The inlet and the flow distribution cavity are connected, and external airflow enters the flow distribution cavity through the inlet. The jet plate has a plurality of jet holes arranged in a spiral structure. The flow distribution cavity and the heat exchange cavity are connected through the jet holes. The airflow forms a swirling flow through the jet holes and enters the heat exchange cavity. The jet plate has a return channel, and the return port and the heat exchange chamber are connected through the return channel. The return channel is used to guide the airflow in the heat exchange chamber to the return port.
2. The jet heat dissipation device according to claim 1, characterized in that, The bottom of the heat exchange cavity is matrix-distributed with conical structural members, which correspond to the jet holes. The conical structural members are used to change the movement path of the swirling flow and increase the heat exchange area.
3. The jet heat dissipation device according to claim 1, characterized in that, The bottom of the heat exchange cavity is matrix-distributed with heat exchange elements for increasing the heat exchange area, and the heat exchange elements are provided with heat exchange holes.
4. The jet heat dissipation device according to claim 1, characterized in that, The return channel includes a first channel and multiple second channels. The first channel is opened along the horizontal direction of the jet plate and is connected to the return port. The multiple second channels are distributed in a matrix and opened along the height direction of the jet plate. One end of each row or column of multiple second channels is connected to the heat exchange cavity, and the other end is connected to the same first channel.
5. The jet heat dissipation device according to claim 1, characterized in that, The helix angle of the jet orifice is 30°, and the height h of the jet orifice is related to the thread pitch diameter d. j Satisfies: h=3d j .
6. The jet heat dissipation device according to claim 1, characterized in that, The distance H from the lower end of the jet hole to the bottom of the heat exchange cavity satisfies the following condition with respect to the inner diameter d of the thread of the jet hole: H = 5d.
7. The jet heat dissipation device according to claim 2, characterized in that, The angle of the tapered structural component is 50°, and the diameter d1 of the tapered structural component and the inner diameter d of the thread satisfy: d1=2d.
8. The jet heat dissipation device according to claim 1, characterized in that, The housing includes a cover for opening and closing the diversion chamber, and the inlet is located on the cover.