A helical microchannel cooling tube incorporating impinging jets

Abstract

This invention relates to a spiral microchannel cooling tube combining impinging jet cooling, comprising a tube body; a central channel in the tube body serving as a central flow guide channel; a spiral microchannel disposed within the tube body, surrounding the central flow guide channel; a coolant inlet at one end of the central flow guide channel; impinging holes surrounding the central flow guide channel; and communication between the central flow guide channel and the spiral microchannel via the impinging holes. An annular collecting cavity is provided at the end of the tube body opposite the coolant inlet, and the end of the spiral microchannel communicates with the annular collecting cavity, which has a coolant outlet. This invention discloses a spiral microchannel cooling tube combining impinging jet cooling. This device achieves efficient, uniform, and low-energy-consumption heat dissipation through the synergistic effect of periodic impinging cooling and microchannel swirling flow, making it suitable for electronic equipment, industrial equipment, and other fields.

Description

Technical Field

[0001] This invention belongs to the field of thermal management technology and relates to a spiral microchannel cooling tube that combines impingement jet. Background Technology

[0002] With the continuous development of electronic and industrial equipment, their power density and heat flux density are constantly increasing, making heat dissipation a key factor restricting equipment performance improvement and stable operation. For example, data center energy consumption already accounts for 1% to 3% of global total energy consumption, with the Asia-Pacific region experiencing the most significant market growth. In high-performance electronic devices, such as CPUs and GPUs, the local heat density can even exceed 1 kW / cm². 2 Traditional heat dissipation technologies are insufficient to meet the requirements. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes a spiral microchannel cooling tube that combines an impinging jet with a spiral microchannel. This cooling tube achieves efficient, uniform, and low-energy-consumption heat dissipation through the organic combination of the spiral microchannel and the impinging jet device, making it suitable for electronic devices, industrial equipment, and other fields.

[0004] The technical solution of this invention to solve the above problems is: a spiral microchannel cooling tube combined with impinging jet, which is special in that:

[0005] Includes tube body;

[0006] The channel at the center of the tube is a central flow guiding channel. The tube is equipped with a spiral microchannel, which surrounds the central flow guiding channel. The central flow guiding channel is equipped with impact holes, and the central flow guiding channel is connected to the spiral microchannel through the impact holes.

[0007] One end of the central guide channel is a coolant inlet, and the tube body is provided with an annular collecting cavity at the end opposite to the coolant inlet. The end of the spiral microchannel is connected to the annular collecting cavity, and the annular collecting cavity is provided with a coolant outlet.

[0008] Furthermore, there are multiple spiral microchannels, which are evenly distributed around the central guide channel; the length of the central guide channel is 0.7 to 0.9L, where L is the length of the tube body.

[0009] Furthermore, the section from the coolant inlet to the starting end of the spiral microchannel on the aforementioned tube body is the inlet section, and the length N of the inlet section is 2 to 4 times R0, where R0 is the diameter of the central guide channel.

[0010] Furthermore, the aforementioned impact holes are perpendicular to the axial direction of the central guide channel and are evenly distributed circumferentially along the central guide channel in an alternating array. The cooling working fluid is sprayed outward through the impact holes of the impact jet layer, forming a high-speed jet that vertically impacts the surface being cooled, thereby achieving rapid cooling with localized high heat flux density.

[0011] Furthermore, the jet coverage density can be controlled by the array distribution of the impact holes. The hole spacing d is set to 1 to 4 impact holes according to each spiral cycle. The hole diameter r2 of the impact hole is required to be smaller than the inner diameter of the spiral microchannel and is 0.5 to 1 times the height of the impact hole to ensure the balance between structural strength and jet penetration force. The height of the impact hole is (R1-R0), where R1 is the inner diameter of the spiral microchannel.

[0012] Furthermore, the aforementioned spiral microchannel is a spiral flow channel etched into the tube wall inside the tube. The working fluid that has completed the impact cooling enters the spiral microchannel and generates continuous swirling flow induced by the spiral structure. The thermal boundary layer is stripped away through the centrifugal effect and the effective heat exchange path is extended.

[0013] Furthermore, the helix angle θ of the aforementioned spiral microchannel is 25° to 75°; the cross-sectional depth-to-width ratio of the spiral microchannel is 1.5:1 to 2:1 to enhance the secondary flow intensity; the cross-section of the spiral microchannel can be rectangular, trapezoidal, circular, or other shapes.

[0014] Furthermore, the length M of the annular flow collector cavity is 0.5 to 1 times the pitch of the spiral microchannel to ensure a smooth flow transition. The inner diameter R1 of the annular flow collector cavity is the same as the inner wall diameter of the spiral microchannel, and the outer diameter R2 of the annular flow collector cavity is the same as the outer wall diameter of the spiral microchannel.

[0015] Furthermore, the coolant outlet is a tubular outlet perpendicular to the side wall of the annular collector cavity, which will complete the final working fluid discharge system for enhanced heat exchange.

[0016] Furthermore, the ratio of the inner diameter r1 of the coolant outlet to the equivalent diameter of the spiral microchannel is 1:1 to 2:1 to match the flow expansion requirements. In addition, it can be set as a gradually widening structure with a widening angle of 8° to 12° to avoid flow separation while maximizing pressure recovery.

[0017] Advantages of this invention:

[0018] This invention describes a spiral microchannel cooling tube combining impingement jets. Microchannel cooling technology, due to its efficient flow and heat transfer performance, has become one of the effective ways to solve the problem of heat dissipation in high heat flux density. The size of microchannels is typically on the micrometer to millimeter scale, resulting in a large surface area to volume ratio of the fluid within the channel and the formation of laminar flow within the channel, allowing heat to be rapidly transferred to the fluid, thereby achieving efficient heat dissipation. The spiral microchannel, with its unique spiral shape, can provide a larger surface area within a limited space, while increasing the turbulent flow of the fluid, helping to break the boundary layer and making the heat transfer between the fluid and the wall more complete. Based on the heat dissipation advantages of impingement cooling in local hot spots, and enhancing flow mixing within the channel, a spiral microchannel cooling tube combining impingement jets is designed to enhance local heat transfer in the spiral microchannel and improve temperature uniformity. This invention achieves a multi-stage enhanced heat transfer mechanism of "jet injection - swirling flow maintenance - dynamic boundary layer control" through the coupling of impingement jets and spiral flow, to achieve efficient and uniform heat dissipation. It can be widely used in high heat flux density electronic equipment, industrial equipment, and other fields, effectively improving the operating efficiency and stability of equipment and extending its service life. In addition, the cooling pipe has the advantages of strong scalability and stable system performance. It can be customized and optimized according to different heat dissipation requirements to meet diverse application scenarios. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the spiral microchannel cooling tube proposed in this invention;

[0020] Figure 2 The left image shows a side view of the spiral microchannel cooling tube, and the right image shows a schematic diagram of the overall structure of the fluid domain excluding the tube body.

[0021] Figure 3 This is a partial structural view of one spiral cycle of a spiral microchannel cooling tube. The left side shows the distribution of impact holes, and the right side shows a schematic diagram of the combined impact hole structure of the spiral microchannel.

[0022] Figure 4 This is a front view of a spiral microchannel cooling tube.

[0023] Figure 5 The left side view shows the overall dimensions of the spiral microchannel cooling tube, while the right side shows a schematic diagram of the microchannel structure dimensions excluding a single spiral cycle of the tube body.

[0024] Figure 6 This is a flow diagram of coolant in a single spiral microchannel branch.

[0025] 1. Pipe body, 2. Coolant inlet, 3. Central guide channel, 4. Impact hole, 5. Spiral microchannel, 6. Annular collector cavity, 7. Coolant outlet. Detailed Implementation

[0026] 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 a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0027] See appendix Figures 1-6 This invention proposes a spiral microchannel cooling tube combining impingement jets, comprising a tube body 1; the central channel of the tube body 1 is a central guide channel 3, and a spiral microchannel 5 is provided inside the tube wall of the tube body 1, surrounding the central guide channel 3. One end of the central guide channel 3 is a coolant inlet 2, and an annular collecting cavity 6 is provided at the end of the tube body 1 opposite to the coolant inlet 2. Impingement holes 4 are provided around the central guide channel 3, and the central guide channel 3 communicates with the spiral microchannel 5 through the impingement holes 4. The end of the spiral microchannel 5 communicates with the annular collecting cavity 6, and a coolant outlet 7 is provided on the annular collecting cavity 6, which is used to collect the outflow working fluid after heat exchange from each branch spiral microchannel.

[0028] After the cooling medium is injected through the central guide channel 3, it forms a high-speed jet through the impact hole 4, vertically impacting the high heat flux density surface, generating strong turbulence and shear force, rapidly carrying away heat and achieving localized, instantaneous enhanced heat transfer. The impacted medium enters the spiral microchannel 5, where the spiral geometry induces secondary swirling flow, continuously stripping the thermal boundary layer and extending the effective heat transfer path through centrifugal effect. The spiral structure design of the microchannel increases the heat dissipation area and optimizes fluid distribution, improving heat dissipation efficiency while reducing pressure drop loss, exhibiting good spatial adaptability and structural compactness.

[0029] Specifically, the tube 1 is a cylindrical high-strength metal body, and its wall surface forms the outer heat transfer surface of the spiral microchannel, serving as the main load-bearing structure of the device and providing mechanical strength support and flow channel sealing. The central guide channel 3 is used for the introduction and flow distribution of coolant. The inner diameter and length of the central guide channel 3 need to be accurately calculated according to the cooling requirements and system pressure to ensure that the coolant can enter the spiral microchannel at an appropriate speed and flow rate.

[0030] The impact orifice connects the central tube and the spiral microchannel, impinging the coolant onto the heat source surface in the form of a high-speed jet. This rapidly removes a large amount of heat, achieving enhanced localized heat transfer. The diameter of the impact orifice must be taken into account the size of the spiral microchannel to prevent excessive flow resistance within the channel.

[0031] The spiral microchannels are arranged in a spiral pattern with multiple continuous spiral coils. The inner and outer diameters of each spiral coil can be designed and optimized according to heat dissipation requirements. The spiral microchannels increase the heat dissipation area, optimize fluid distribution, and meet the heat dissipation requirements in high heat flux density scenarios.

[0032] During operation, the coolant within the spiral microchannel cooling pipe flows in an annular pattern. Centripetal acceleration creates a high-velocity region at the outer edge of the pipe, enhancing heat dissipation when the heat source is the outer ring of the spiral microchannel. The impact jet, passing through the impact holes, forms a stagnant zone on the wall, combining with the spiral flow to enhance flow and heat transfer. The shear force generated by the jet and the spiral flow effectively suppresses boundary layer flow separation. The impact and entrainment effects of the jet create two additional secondary vortices, which are then gradually dissipated. The uniform distribution of the impact jet further promotes uniform heat transfer, preventing localized overheating.

[0033] In some embodiments provided by the present invention, there are multiple spiral microchannels 5, which are uniformly distributed around the central guide channel 3. The central guide channel 3 is located at the axis of the device, and the working fluid flows axially along the central guide channel 3 to form a uniform initial flow field. The length of the central guide channel 3 is 0.7 to 0.9L, where L is the length of the tube body 1.

[0034] Furthermore, the wall thickness of tube 1 is positively correlated with its diameter, ensuring that the structural stiffness matches the thermal expansion.

[0035] In some embodiments provided by the present invention, see Figure 4 The tube body 1 has an inlet section from the coolant inlet 2 to the starting end of the spiral microchannel 5. The length N of the inlet section is 2 to 4 times R0, where R0 is the inner diameter of the central guide channel 3.

[0036] In some embodiments provided by the present invention, see Figures 1-6 The impact holes 4 are perpendicular to the axis of the central guide channel 3 and are evenly distributed circumferentially along the central guide channel 3 in a staggered array. The cooling working fluid is sprayed outward through the microholes of the impact jet layer, forming a high-speed jet that vertically impacts the surface being cooled, achieving rapid cooling with localized high heat flux density.

[0037] In some embodiments provided by the present invention, see Figure 5 The jet coverage density can be controlled by the distribution of the hole array. 1 to 4 impact holes are set in each spiral cycle. The diameter r2 of the impact hole 4 is required to be smaller than the inner diameter of the spiral microchannel 5, and is 0.5 to 1 times the height of the impact hole 4 to ensure the balance between structural strength and jet penetration. The height of the impact hole 4 is (R1-R0), where R1 is the inner diameter of the spiral microchannel 5.

[0038] In some embodiments provided by the present invention, the outer spiral microchannel 5 is a spiral flow channel etched on the inner wall of the tube body 1. The working fluid that has completed the impact cooling enters the spiral microchannel and generates a continuous swirling flow induced by the spiral structure. The thermal boundary layer is stripped off through the centrifugal effect and the effective heat exchange path is extended.

[0039] Further, see Figure 5 The spiral angle θ of the spiral microchannel 5 is 25° to 75°; the depth-to-width ratio of the channel cross section of the spiral microchannel 5 is 1.5:1 to 2:1 to enhance the secondary flow intensity. In addition, the channel cross section can be rectangular, trapezoidal, circular or other shapes.

[0040] Furthermore, the number of branches in a spiral microchannel can be changed according to heat exchange requirements and flow resistance limitations.

[0041] In some embodiments provided by this invention, the axial length M of the cavity is 0.5 to 1 times the pitch of the helical microchannel to ensure a smooth flow transition. The inner diameter R1 is consistent with the inner wall diameter of the helical tube, and the outer diameter R2 is consistent with the outer wall diameter of the helical tube.

[0042] In some embodiments provided by the present invention, see Figure 4 The coolant outlet 7 is a tubular outlet perpendicular to the annular collector cavity 6, which will complete the final working fluid discharge system for enhanced heat exchange.

[0043] Specifically, the ratio of the inner diameter r1 of the coolant outlet 7 to the equivalent diameter of the spiral microchannel is 1:1 to 2:1 to match the flow expansion requirements. In addition, the coolant outlet 7 can also be set as a gradually widening structure with a widening angle of 8° to 12° to avoid flow separation while maximizing pressure recovery.

[0044] The cooling structure proposed in this invention, which couples impinging jets with spiral microchannels, enhances heat transfer by achieving dynamic disruption of the thermal boundary layer and efficient coverage of the heat transfer surface through the synergistic effect of multi-stage flow modes.

[0045] Specifically (see Appendix) Figure 6 Taking a single spiral microchannel branch as an example, the flow direction of its coolant is explained. After the working fluid is injected axially from the central guide channel 3, a uniform and stable initial flow field (C1) is formed. When the working fluid is sprayed outward through the circumferentially distributed impact holes 4, a high-speed and dense micro-jet array (C2) is formed, which vertically impacts the cooled surface and enters the spiral microchannel 5.

[0046] This impact has a dual reinforcing effect:

[0047] Firstly, the high velocity (C3) in the jet core region directly penetrates the stagnant boundary layer of traditional convective heat transfer, rapidly entraining and detaching the high-temperature fluid near the wall, enabling the cold fluid to directly contact the hot surface and significantly improving the local convective heat transfer intensity.

[0048] Secondly, the radial wall jet (C4) formed by the impact jet spreading on the wall surface induces strong turbulent pulsations through shearing action, further disturbing the thermal boundary layer and enhancing heat exchange in the near-wall region.

[0049] After the working fluid has completed the impact cooling, it mixes with the preceding fluid that has been flowing in the spiral microchannel 5, namely the working fluid from the upstream spiral section (C5), at the impact outlet, and then flows in a spiral (C6).

[0050] Meanwhile, the periodic injection of the impacting working fluid creates unsteady disturbances in the spiral microchannel, inducing unstable waves and causing intermittent rupture of the thermal boundary layer.

[0051] The mechanism of enhanced heat transfer by spiral motion is twofold: firstly, centrifugal force continuously throws the low-temperature working fluid toward the high-heat flux wall outside the channel, forming forced wall-attached flow and prolonging the effective contact time between the working fluid and the heat transfer surface; secondly, the transverse momentum exchange caused by the swirling flow continuously destroys the already formed thermal boundary layer, making the wall temperature distribution tend to be uniform.

[0052] Finally, the working fluid (C7) that has completed the heat exchange in the spiral microchannel moves along the spiral flow channel to the end outlet section, and multiple flow branches converge into the annular collection cavity 6.

[0053] At this point, the annular cavity will normalize the flow of the microchannel fluid, which has uneven flow state, uneven temperature distribution, and contains residual swirling energy, and discharge the rectified working fluid (C8) through the tubular outlet.

[0054] In summary, this invention constructs an enhanced heat transfer system of "jet injection - swirling flow maintenance - boundary layer dynamic control" by coupling impingement cooling with helical flow. This design not only overcomes the technical bottleneck of traditional cooling structures in high-temperature regions, but also achieves synergistic optimization of heat dissipation performance and energy consumption characteristics through the stepped utilization of flow energy, providing an innovative solution for compact thermal management of high heat flux density equipment.

[0055] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related system fields, are similarly included within the scope of protection of the present invention.

Claims

1. A spiral microchannel cooling tube incorporating impingement jet, characterized in that: Includes tube body(1); The central channel of the tube body (1) is a central flow channel (3). The tube body (1) is provided with a spiral microchannel (5). The spiral microchannel (5) surrounds the central flow channel (3). One end of the central flow channel (3) is a coolant inlet (2). The central flow channel (3) is provided with an impact hole (4) on its periphery. The central flow channel (3) is connected to the spiral microchannel (5) through the impact hole (4). The tube body (1) is provided with an annular flow-collecting cavity (6) at one end relative to the coolant inlet (2), the end of the spiral microchannel (5) is connected to the annular flow-collecting cavity (6), and the annular flow-collecting cavity (6) is provided with a coolant outlet (7).

2. The spiral microchannel cooling tube combining impinging jet according to claim 1, characterized in that: The number of spiral microchannels (5) is multiple, and the multiple spiral microchannels (5) are evenly distributed around the central guide channel (3); the length of the central guide channel (3) is 0.7 to 0.9L, where L is the length of the tube body (1).

3. A spiral microchannel cooling tube combining impinging jets according to claim 2, characterized in that: The tube body (1) has an inlet section from the coolant inlet (2) to the starting end of the spiral microchannel (5). The length N of the inlet section is 2 to 4 times R0, and R0 is the inner diameter of the central guide channel (3).

4. A spiral microchannel cooling tube combining impinging jets according to claim 3, characterized in that: The impact holes (4) are perpendicular to the axis of the central guide channel (3) and are evenly distributed around the central guide channel (3) in an alternating array.

5. A spiral microchannel cooling tube combining impinging jets according to claim 4, characterized in that: Each spiral cycle of the spiral microchannel (5) is provided with 1 to 4 impact holes. The diameter r2 of the impact hole (4) is required to be smaller than the inner diameter of the spiral microchannel (5) and is 0.5 to 1 times the height of the impact hole (4) to ensure that the structural strength and jet penetration force are balanced. The height of the impact hole (4) is (R1-R0), where R1 is the inner diameter of the spiral microchannel (5).

6. A spiral microchannel cooling tube combining impinging jets according to claim 1, characterized in that: The spiral microchannel (5) is a spiral flow channel etched on the wall of the tube body (1).

7. A spiral microchannel cooling tube combining impinging jets according to claim 5, characterized in that: The spiral angle θ of the spiral microchannel (5) is 25° to 75°; the depth-to-width ratio of the cross section of the spiral microchannel (5) is 1.5:1 to 2:1; and the cross section of the spiral microchannel (5) is rectangular, trapezoidal, or circular.

8. A spiral microchannel cooling tube combining impinging jets according to claim 7, characterized in that: The length M of the annular collecting cavity (6) is 0.5 to 1 times the pitch of the spiral microchannel (5). The inner diameter R1 of the annular collecting cavity (6) is equal to the inner wall diameter of the spiral microchannel (5), and the outer diameter R2 of the annular collecting cavity (6) is equal to the outer wall diameter of the spiral microchannel (5).

9. A spiral microchannel cooling tube combining impinging jets according to claim 8, characterized in that: The coolant outlet (7) is a tubular outlet perpendicular to the side wall of the annular collector cavity (6).

10. A spiral microchannel cooling tube combining impinging jets according to claim 9, characterized in that: The ratio of the inner diameter r1 of the coolant outlet (7) to the equivalent diameter of the spiral microchannel (5) is 1:1 to 2:1.

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