A V-concave-spherical concave connection type enhanced heat transfer structure
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2022-10-31
- Publication Date
- 2026-06-30
AI Technical Summary
Existing composite structures have relatively low overall thermal performance when heat exchange is enhanced, and under high flow conditions, they lead to increased pressure loss and a rapid increase in power consumption of system pumps or fans.
A V-concave-spherical concave connection type enhanced heat transfer structure is adopted. By setting an orderly arrangement of concave units on the substrate, including interconnected spherical concaves and V-concaves, the V-concave design disrupts the spherical concave backflow and forms a secondary flow to improve the heat transfer capacity.
It improves heat transfer performance with less pressure loss, enhances the transfer of matter and energy within the fluid, and reduces the impact of flow dead zones.
Smart Images
Figure CN115790240B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of heat transfer devices, specifically relating to a V-concave-spherical concave connection type enhanced heat transfer structure. Background Technology
[0002] With the vigorous development of modern industry, power devices are developing towards higher heat flux densities. To ensure the safe and stable operation of equipment, there is an urgent need for heat transfer devices with low flow resistance and high heat transfer performance to transfer the heat generated by the devices to the atmosphere or other external heat sinks.
[0003] Enhanced heat transfer technology refers to techniques that increase the heat transfer coefficient or convective heat transfer coefficient under a given heat transfer area and temperature difference. Adding fins, slots, or recesses to the flow channel walls to enhance heat exchange capacity is a common method in passive enhanced heat transfer technology. Among these, recessed structures, as a highly efficient heat exchange structure, have the following characteristics compared to smooth walls: 1) When fluid flows through a recess, under the action of the adverse pressure gradient, some fluid flows back at low speed, forming a dead zone on the leeward side of the recess, resulting in poor heat transfer capacity; other fluid adheres to the windward side of the recess, forming a new boundary layer, and flows upward along the recess wall, impacting the mainstream fluid, enhancing the mixing of cold and hot fluids and improving heat transfer capacity. 2) Since the recessed structure only increases fluid disturbance near the wall surface, it has little impact on the mainstream fluid movement, thus causing less pressure loss. In summary, recessed structures possess excellent comprehensive thermal performance and are applied in many fields. Typically, the array of recessed structures is either a cross-shaped array or a straight array, and the cross-sectional shape of the recess is part of a triangle, quadrilateral, ellipse, teardrop, or other shapes.
[0004] Conventional recessed structures have significant limitations: fluid in the dead zone on the leeward side of the recess does not easily flow out, resulting in a low local heat transfer coefficient. Furthermore, due to stringent requirements on the size, weight, and energy consumption of heat exchange devices in fields such as chemical engineering, machinery, and aerospace, researching heat transfer devices with high heat transfer performance and low flow resistance is particularly important. To further enhance heat transfer, some researchers have optimized conventional recessed structures by combining them with ribs, columns, and protrusions. While these composite structures improve heat transfer performance, they also cause significant pressure losses in the fluid, especially under high flow rates, resulting in lower overall thermal performance and ultimately a rapid increase in the power consumption of pumps or fans in the system. Summary of the Invention
[0005] The purpose of this invention is to solve the problem of low overall thermal performance of composite structures when enhancing heat transfer in a system. This invention provides a V-concave-spherical concave connection type enhanced heat transfer structure, which can improve heat transfer at the leeward side of the spherical concave and enhance the heat transfer capacity of the concave unit with a small increase in pressure loss, thereby improving its overall thermal performance.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A V-concave-spherical concave connection type enhanced heat transfer structure includes a substrate. Several concave units are arranged in an orderly and cross-shaped manner on one side wall of the substrate. The other walls of the substrate are flat. The concave units include spherical concave and V-concave, and the spherical concave and V-concave are connected.
[0008] Furthermore, the V-shaped concave is V-shaped, the included angle of the V-shaped channel of the V-shaped concave is 60°, and the top of the V-shaped concave is rounded and points towards the incoming flow.
[0009] Furthermore, the cross-sectional shape of the V-concave is part of an ellipse, and the depth h of the V-concave does not exceed the length of the minor semi-axis of the ellipse.
[0010] Furthermore, the cross-sectional shape of the spherical concave is a portion of a circle, and the depth H of the spherical concave does not exceed the radius of the circle.
[0011] Furthermore, the depth of the spherical concave is not less than the depth of the V-concave.
[0012] Furthermore, the two channels of the V-shaped concave penetrate the leeward side of the spherical concave, and the tail of the channel of the V-shaped concave does not intersect with the windward side of the spherical concave.
[0013] Furthermore, the V-shaped depression is arranged upstream of the corresponding spherical depression in the direction of incoming flow and is connected to the spherical depression. The axis of symmetry of the V-shaped depression passes through the center of the spherical depression and its projection on the substrate is parallel to the direction of incoming flow.
[0014] Furthermore, the two spherical concaves are connected in the span direction by a V-shaped concave located at the midpoint between the two connected spherical concaves.
[0015] Compared with the prior art, the present invention has the following beneficial technical effects:
[0016] This invention provides a V-concave-spherical concave interconnected enhanced heat transfer structure, which has several orderly arranged, staggered concave units on one side wall of a substrate. Each concave unit includes interconnected spherical and V-concave sections, while the other sides of the substrate are flat. This discontinuous arrangement of concave units can periodically and continuously disturb the boundary layer, allowing the structure to improve heat transfer performance without incurring significant pressure loss, thereby enhancing its overall thermal performance.
[0017] Furthermore, the two channels of the V-shaped depression penetrate the leeward side of the spherical depression, and the tail of the V-shaped depression channel does not intersect with the windward side of the spherical depression, thereby eliminating other depressions inside the spherical depression, avoiding backflow and reducing the heat transfer capacity of the depression.
[0018] Furthermore, several V-shaped depressions are arranged upstream of and connected to several spherical depressions in the direction of incoming flow. The axis of symmetry of the V-shaped depressions passes through the center of the spherical depressions, and its projection on the substrate is parallel to the direction of incoming flow. Since the leeward side of the spherical depressions is prone to dead flow zones, the fluid does not easily flow out from them, resulting in poor heat transfer. However, a secondary flow similar to that induced by V-ribs is generated in the V-shaped depression channel upstream of the spherical depressions. This secondary flow mainly affects the backflow at the leading edge of the spherical depressions. When this secondary flow flows through the spherical depression structure, it disrupts the dead flow zones of the spherical depressions, reduces the backflow, improves the heat transfer performance at the leeward side of the spherical depressions, and enhances heat transfer.
[0019] Furthermore, several spherical concave structures are connected in the spanwise direction by several V-shaped concave structures, with the V-shaped concave structures located in the middle of adjacent spherical concave structures. By arranging the V-shaped concave structures between adjacent spherical concave structures in the spanwise direction, a secondary flow similar to that induced by V-ribs is generated at the two channels of the V-shaped concave when the fluid flows through the concave. At this time, the secondary flow formed in the V-shaped concave channel mainly affects the backflow near the end of the V-shaped concave in the spherical concave, causing the fluid to flow out of the concave quickly, enhancing the transfer of matter and energy within the fluid, thereby improving the heat transfer capacity of the element. Attached Figure Description
[0020] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0021] Figure 1 This is a schematic diagram of the non-stretching connected V-concave-spherical concave structure of the present invention.
[0022] Figure 2 This is a schematic diagram of the spanwise connected V-concave-spherical concave structure of the present invention.
[0023] Figure 3 These are enlarged views and partial sectional views of the present invention, wherein (a) is... Figure 1 A magnified view of a portion, (b) is... Figure 2 Enlarged view of a section, (c) is Figure 2 Partial sectional view.
[0024] Figure 4 The diagram shows a three-dimensional streamline turbulence of a concave structure, where (a) is a spherical concave structure, (b) is a non-stretched V-concave-spherical concave structure, and (c) is a stretched V-concave-spherical concave structure.
[0025] Where 1 is the spherical concave, 2 is the V-concave, 3 is the substrate, 4 is the flow direction arrow, h is the depth of the V-concave, and H is the depth of the spherical concave. Detailed Implementation
[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.
[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0028] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.
[0029] See Figure 1 and Figure 2 A V-concave-spherical concave interconnected enhanced heat transfer structure includes a spherical concave 1, a V-concave 2, and a substrate 3. The spherical concave 1 is used to increase the heat transfer coefficient, and the V-concave 2 is used to increase the heat transfer coefficient and disrupt the reflux in the spherical concave. The substrate 3 is a metal plate with high thermal conductivity. Several orderly arranged, staggered recessed units are located on one side wall of the substrate 3. The recessed units include spherical concave 1 and V-concave 2. The other walls of the substrate 3 are flat. This discontinuous arrangement of recessed units can periodically and continuously disturb the boundary layer, allowing the structure to improve heat transfer performance without causing significant pressure loss, thereby improving its overall thermal performance.
[0030] The V-shaped concave section 2 has a V-shape with a 60° included angle. The top of the V-shape is rounded, and the top of the V-shape points towards the incoming flow (as shown by arrow 4 in the flow direction). Figure 3 (a), (b) and Figure 4 As shown in (b) and (c), this V-shaped depression causes the fluid to form a secondary flow similar to that induced by the V-rib at the two channels when it flows through the V-shaped depression 2, which enhances the fluid disturbance. Moreover, when the secondary flow flows through the leeward side of the spherical depression 1, it destroys the flow dead zone and reduces the thickness of the temperature boundary layer, thereby improving the heat transfer of the spherical depression 1 structure.
[0031] The cross-sectional shape of V-concave 2 is a portion of an ellipse, and the depth h of V-concave 2 does not exceed the minor semi-axis of the ellipse. The cross-sectional shape of spherical concave 1 is a portion of a circle, and the depth H of spherical concave 1 does not exceed the radius of the circle. The depth of spherical concave 1 is not less than the depth of V-concave 2. The two channels of V-concave 2 penetrate the leeward side of spherical concave 1, and the tail of the channel of V-concave 2 does not intersect the windward side of spherical concave 1, such as... Figure 3 As shown, this ensures that no other recessed structures exist within the spherical recess 1, preventing backflow and reducing the heat transfer capacity of the recess. Several V-shaped recesses 2 are arranged upstream of the corresponding spherical recess 1 in the flow direction and connected to the spherical recess 1. The axis of symmetry of the V-shaped recess 2 passes through the center of the spherical recess 1, and its projection on the substrate 3 is parallel to the flow direction. (See diagram) Figure 4 As shown in (a) and (b), since the leeward side of the spherical concave 1 is prone to a flow dead zone, the fluid is not easy to flow out from it, resulting in poor heat transfer. However, a secondary flow can be generated in the V concave 2 channel located upstream of the spherical concave 1. When the secondary flow flows through the structure of the spherical concave 1, it destroys the flow dead zone of the spherical concave 1 and enhances the heat transfer.
[0032] Several spherical concave structures 1 are connected in the spanwise direction by several V-concave structures 2, with the V-concave structures 2 located at the midpoint between adjacent spherical concave structures 1. For example... Figure 4 As shown in (a) and (c), the V-shaped concave 2 structure is arranged between adjacent spherical concave 1 in the spanwise direction. At this time, the secondary flow formed in the V-shaped concave 2 channel mainly affects the backflow near the end of the V-shaped concave 1, causing the fluid to flow out of the concave quickly, which enhances the transfer of matter and energy inside the fluid and thus improves the heat transfer capacity of the element.
[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.
Claims
1. A V-concave-spherical concave connection type enhanced heat transfer structure, characterized in that, The substrate (3) includes a substrate (3), on one side wall of the substrate (3) are arranged a plurality of recessed units in an orderly and cross-arranged manner, and the other side wall of the substrate (3) is flat. The recessed unit includes a spherical recess (1) and a V-shaped recess (2), and the spherical recess (1) and the V-shaped recess (2) are connected. The two channels of the V-shaped concave (2) penetrate the leeward side of the spherical concave (1), and the tail of the channel of the V-shaped concave (2) does not intersect with the windward side of the spherical concave (1).
2. The V-concave-spherical concave connection type enhanced heat transfer structure according to claim 1, characterized in that, The V-shaped concave (2) is V-shaped, with the included angle of the V-shaped channel of the V-shaped concave (2) being 60°, and the top of the V-shaped concave (2) being a rounded transition and pointing towards the incoming flow.
3. The V-concave-spherical concave connection type enhanced heat transfer structure according to claim 1, characterized in that, The cross-sectional shape of the V-concave (2) is part of an ellipse, and the depth h of the V-concave (2) does not exceed the length of the minor semi-axis of the ellipse.
4. The V-concave-spherical concave connection type enhanced heat transfer structure according to claim 1, characterized in that, The cross-sectional shape of the spherical concave (1) is part of a circle, and the depth H of the spherical concave (1) does not exceed the radius of the circle.
5. The V-concave-spherical concave connection type enhanced heat transfer structure according to claim 1, characterized in that, The depth of the spherical concave (1) is not less than the depth of the V-concave (2).
6. The V-concave-spherical concave connection type enhanced heat transfer structure according to claim 1, characterized in that, The V-shaped depression (2) is arranged upstream of the corresponding spherical depression (1) in the direction of incoming flow and is connected to the spherical depression (1). The axis of symmetry of the V-shaped depression (2) passes through the center of the spherical depression (1) and its projection on the substrate (3) is parallel to the direction of incoming flow.
7. The V-concave-spherical concave connection type enhanced heat transfer structure according to claim 1, characterized in that, The two spherical concave (1) are connected in the span direction by a V-shaped concave (2), which is located in the middle of the two connected spherical concave (1).