A heat dissipation device

Abstract

The application discloses a heat dissipation device, comprising a liquid inlet, a liquid outlet, a flow channel and a thermal bimetallic strip, which is used for heat dissipation of electronic devices; wherein the number of the flow channel is one or more, when the flow channel is multiple, the multiple flow channels are arranged in parallel between the liquid inlet and the liquid outlet; each flow channel comprises an inlet section and an outlet section, the inlet section is not arranged with a heating device and is connected with the liquid inlet, the outlet section is arranged with at least one heating device and is connected with the liquid outlet; one or more thermal bimetallic strips are arranged in each flow channel, the first end of the thermal bimetallic strip is connected to the inner wall of the outlet section of the flow channel, the second end of the thermal bimetallic strip is a free end, and the second end is bent in a direction away from the wall surface of the flow channel where the first end is located. By arranging the thermal bimetallic strip in the flow channel, the uniform flow effect of the heat dissipation device is improved.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology for heat-generating devices, and particularly to a heat dissipation device. Background Technology

[0002] In various high-power electronic products, such as automotive inverters and DC-DC buck-boost systems, liquid cooling (water / oil cooling, etc.) is widely used to dissipate heat and cool high-heat-generating components (MOSFETs, IGBTs, power diodes, etc.) to reduce their operating temperature rise and ensure their reliability. Since the characteristics of a single component (such as current carrying capacity) cannot meet system requirements, multiple components are often connected in parallel to achieve the desired function. Furthermore, conventional power circuit topologies (full-bridge, three-phase bridge, etc.) typically contain multiple similar components operating under identical conditions, such as the three symmetrical arms of a three-phase bridge, and the upper and lower halves of each arm. Therefore, high-power electronic products generally contain multiple (up to dozens) symmetrical heat-generating components.

[0003] To ensure stable operation of all heat-generating components, uniform cooling is necessary to maintain their junction temperatures within a similar range. For example... Figure 1 and Figure 2 As shown, the heat dissipation device 01 typically employs multiple sets of parallel flow channels 03 to cool the heat-generating components 02 in different areas. In this case, the uniformity of flow rate among the multiple symmetrically connected parallel flow channels 03 becomes one of the key indicators affecting the temperature consistency of the internal heat-generating components 02, and consequently, the performance of the electronic product. Uneven flow rate among the parallel flow channels 03 will lead to inconsistent cooling of the heat-generating components 02 in the corresponding areas of different flow channels, resulting in uneven flow rate among the flow channels 03.

[0004] Therefore, how to improve the flow uniformity of heat dissipation devices is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a heat dissipation device that improves the flow equalization effect.

[0006] To achieve the above objectives, the present invention provides a heat dissipation device for heat dissipation of electronic devices, including a liquid inlet, a liquid outlet, a flow channel, and a thermal bimetallic strip;

[0007] The number of flow channels is one or more. When there are multiple flow channels, the multiple flow channels are arranged in parallel between the liquid inlet and the liquid outlet. Each flow channel includes an inlet section and an outlet section. No heating device is provided at the inlet section and it is connected to the liquid inlet. At least one heating device is provided at the outlet section and it is connected to the liquid outlet.

[0008] One or more of the thermal bimetallic strips are provided in each of the flow channels. The first end of the thermal bimetallic strip is connected to the inner wall of the outlet section of the flow channel, and the second end of the thermal bimetallic strip is a free end, which is bent away from the flow channel wall where the first end is located relative to the first end.

[0009] Optionally, in the above heat dissipation device, the thermal bimetallic strip is provided on the side of the flow channel near the heat-generating device, and the back side of the position where the first end of the thermal bimetallic strip is located on the flow channel is used to set the heat-generating device.

[0010] Optionally, in the above-described heat dissipation device, the second end of the thermal bimetallic strip is closer to the liquid outlet than the first end of the thermal bimetallic strip.

[0011] Optionally, in the above heat dissipation device, a plurality of thermal bimetallic strips are provided in the same flow channel, and the plurality of thermal bimetallic strips are disposed on the same side of the inner wall of the flow channel.

[0012] Optionally, in the above heat dissipation device, a plurality of thermal bimetallic strips are provided in the same flow channel, and the plurality of thermal bimetallic strips form a first metal strip group and a second metal strip group arranged sequentially along the length direction of the flow channel;

[0013] The first metal sheet group and the second metal sheet group are disposed on two opposite walls of the flow channel and projected along the vertical length direction of the flow channel. The projections of the first metal sheet group and the second metal sheet group partially or completely overlap.

[0014] Optionally, in the above heat dissipation device, a plurality of thermal bimetallic strips are provided in the same flow channel, and the first end of the thermal bimetallic strip is closer to the liquid outlet than the second end of the thermal bimetallic strip.

[0015] Optionally, in the above heat dissipation device, a plurality of thermal bimetallic strips are provided in the same flow channel, and thermal bimetallic strips are provided on two opposite sides of the flow channel, with the first end of the thermal bimetallic strip being closer to the liquid outlet than the second end of the thermal bimetallic strip.

[0016] Optionally, the above-mentioned heat dissipation device further includes a baffle disposed in each of the flow channels. The baffle is closer to the liquid outlet than the second end of the thermal bimetallic strip, and the thermal bimetallic strip and the baffle are disposed on two opposite walls of the flow channel. The baffle protrudes from the wall on its own wall.

[0017] Optionally, in the above-mentioned heat dissipation device, the first end of the baffle is connected to the flow channel, and the second end of the baffle away from the first end is inclined toward the liquid inlet.

[0018] Optionally, in the above-mentioned heat dissipation device,

[0019] The passive layer alloy of the thermal bimetallic strip is Invar alloy, and the active layer alloy is manganese-copper-nickel alloy.

[0020] And / or,

[0021] The bimetallic strip is rectangular in shape, and its width is the same as that of a single flow channel. One end of the bimetallic strip along its length is fixed to the flow channel wall, and the other end is a free end. Alternatively, one end of the bimetallic strip along its width is fixed to the flow channel wall, and the other end is a free end.

[0022] Optionally, in the above heat dissipation device, the length of the thermal bimetallic strip is designed such that, under rated operating temperature, the bending amount of the thermal bimetallic strip causes the free end to bend up to 70% of the channel depth; when the temperature increases by 40°C compared to the rated operating temperature, the bending curvature of the thermal bimetallic strip becomes 0.

[0023] In the above technical solution, the heat dissipation device provided by the present invention is used for heat dissipation of electronic devices, including a liquid inlet, a liquid outlet, a flow channel, and a bimetallic strip; wherein, the number of flow channels is one or more, and multiple flow channels are arranged in parallel between the liquid inlet and the liquid outlet; each flow channel includes an inlet section and an outlet section, the inlet section is not provided with a heating device and is connected to the liquid inlet, and the outlet section is provided with at least one heating device and is connected to the liquid outlet; one or more bimetallic strips are provided in each flow channel, the first end of the bimetallic strip is connected to the inner wall of the outlet section of the flow channel, and the second end of the bimetallic strip is a free end, which is bent relative to the first end in a direction away from the wall where the first end is located. In the heat dissipation device provided in this application, by providing a bimetallic strip in the flow channel, as the temperature rises, the free end of the bimetallic strip bends towards the fixed end, the area of ​​the flow liquid interface occupied by the bimetallic strip in the flow channel decreases, the flow rate of the coolant flowing through the bimetallic strip in the flow channel increases, the flow rate of the flow channel with low flow rate increases, and thus the flow uniformity effect of the heat dissipation device is improved. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a traditional heat dissipation device.

[0026] Figure 2 This is a schematic diagram of another traditional heat dissipation device.

[0027] Figure 3 This is a diagram showing the installation positions of the bimetallic strip and the heating element provided in an embodiment of the present invention.

[0028] Figure 4 This is a diagram showing the installation positions of multiple bimetallic thermocouples provided in an embodiment of the present invention.

[0029] Figure 5 This is a diagram showing the installation positions of the first metal sheet group and the second metal sheet group provided in an embodiment of the present invention;

[0030] Figure 6 A diagram showing the coolant flow direction at low temperatures when a baffle is provided in the heat dissipation device provided in this embodiment of the invention;

[0031] Figure 7 A diagram showing the coolant flow direction at high temperatures for the heat dissipation device provided in this embodiment of the invention, with a baffle element.

[0032] Figure 8 A diagram showing the coolant flow direction at high temperatures for a single row of bimetallic heat sinks provided in the embodiments of the present invention.

[0033] Figure 9 A diagram showing the coolant flow direction at high temperatures for the heat dissipation device provided in this embodiment of the invention, which features a double-row bimetallic heat sink.

[0034] Figure 10 This is a schematic diagram of the heat dissipation device structure provided in an embodiment of the present invention.

[0035] in Figure 1-10 middle:

[0036] 01. Heat dissipation device; 02. Heat-generating component; 03. Flow channel;

[0037] 1. Flow channel; 2. Heating element;

[0038] 3. Thermo-bimetallic strip; 3A. First metal strip group; 3B. Second metal strip group;

[0039] 4. Liquid inlet; 5. Liquid outlet; 6. Inlet section; 7. Outlet section; 8. Baffle; 9. Flow equalization installation position. Detailed Implementation

[0040] The core of this invention is to provide a heat dissipation device that improves the flow equalization effect.

[0041] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0042] Please refer to Figures 2 to 10 .

[0043] In one specific embodiment, the heat dissipation device provided by this invention, used for heat dissipation of electrical devices, includes an inlet 4, an outlet 5, a flow channel 1, and a bimetallic strip 3. The bimetallic strip 3 with a higher coefficient of thermal expansion is called the active layer; the one with a lower coefficient of thermal expansion is called the passive layer. The passive layer alloy of the bimetallic strip 3 is Invar alloy, which has a low coefficient of thermal expansion, while the active layer alloy is a manganese-copper-nickel alloy, which has a high coefficient of thermal expansion.

[0044] The bimetallic strip 3 is rectangular in shape, with a width equal to that of a single flow channel 1. One end is fixed to the wall of the flow channel 1, and the other end is free. Specifically, one end of the bimetallic strip 3 along its length is fixed to the wall of the flow channel 1, and the other end is free.

[0045] Alternatively, one end of the bimetallic strip 3 in the width direction can be fixed to the wall of the flow channel 1, while the other end is a free end.

[0046] Specifically, the length of the bimetallic strip 3 is designed such that, under rated operating temperature, the bending amount of the bimetallic strip 3 causes the free end to bend up to 70% of the depth of the flow channel 1, meaning that the depth direction occupies 70% of the cross-sectional area of ​​the flow channel 1. When the temperature increases by 40°C compared to the rated operating temperature, the bending curvature of the bimetallic strip 3 becomes 0. At this time, the bimetallic strip 3 can be fitted to the corresponding wall surface of the flow channel 1.

[0047] The number of flow channels 1 is one or more. When there are multiple flow channels 1, the multiple flow channels 1 are arranged in parallel between the liquid inlet 4 and the liquid outlet 5; each flow channel 1 includes an inlet section 6 and an outlet section 7. The inlet section 6 is not equipped with a heating device 2 and is connected to the liquid inlet 4, while the outlet section 7 is equipped with at least one heating device 2 and is connected to the liquid outlet 5.

[0048] Specifically, a hot bimetallic strip 3 is provided in the flow channel 1, or multiple hot bimetallic strips 3 are provided in the flow channel 1. Preferably, the hot bimetallic strips 3 in the same flow channel 1 are arranged sequentially along the liquid flow direction in the flow channel 1. The first end of the hot bimetallic strip 3 is connected to the inner wall of the outlet section 7 of the flow channel 1, and the second end of the hot bimetallic strip 3 is a free end. The second end is bent relative to the first end in a direction away from the wall where the first end is located.

[0049] Preferably, a bimetallic strip 3 is provided on the side of the flow channel 1 near the heating element 2, and the back side of the position where the first end of the bimetallic strip 3 is located on the flow channel 1 is used to mount the heating element 2. Specifically, when the heating element 2 is located on the upper wall of the flow channel 1, preferably, the bimetallic strip 3 is mounted on the upper wall of the flow channel 1, and the bimetallic strip 3 can be bent toward the lower wall of the flow channel 1.

[0050] When there are multiple flow channels 1, they are arranged in parallel between the inlet 4 and the outlet 5. Preferably, the flow channel 1 has a straight strip structure, and the multiple flow channels 1 are symmetrically arranged on both sides of the line connecting the inlet 4 and the outlet 5 as the center line. Specifically, there can be 2, 3, 4, etc. When the environment of the hot bimetallic strip 3 increases, the second end of the hot bimetallic strip 3 bends towards the wall where the first end is located; when the environment of the hot bimetallic strip 3 decreases, the second end of the hot bimetallic strip 3 bends towards the wall opposite to the first end.

[0051] Specifically, the flow channel 1 is provided with a flow equalization mounting position 9 for mounting the hot bimetallic strip 3.

[0052] Specifically, the bimetallic strip 3 comprises multiple strips, preferably multiple bimetallic strips 3 are disposed in each flow channel 1. Preferably, the multiple bimetallic strips 3 in each flow channel 1 are arranged sequentially along the length of the flow channel 1.

[0053] In one specific embodiment, the number of thermal bimetallic strips 3 in each flow channel 1 is equal. The thermal bimetallic strips 3 in each flow channel 1 can be distributed at equal or unequal intervals.

[0054] Specifically, the cooling channels 1 arranged in parallel are equipped with heat sinks and multiple heating elements 2 attached to the heat sinks. The heating elements 2 are fixed to the channels 1 by welding, screw fastening, or other means, and the heat generated by the heating elements 2 is transferred to the coolant in the channels 1 through the shell of the channels 1.

[0055] Specifically, such as Figure 3 As shown, a corresponding bimetallic strip 3 is provided at the bottom of each heating element 2 within each parallel flow channel 1. The bimetallic strip 3 is fixed to the inner wall of the cooling flow channel 1 near the heating element 2. Its temperature rise-deformation characteristic is that when the temperature rises, the bimetallic strip 3 bends towards its fixed end (first end). Figure 3 (on the upper side), occupying a smaller flow channel area; when the temperature decreases, it bends to the opposite side from the fixed end ( Figure 3 The lower side of the flow channel 1 occupies a larger area. For the same flow channel 1 connected in parallel, this application preferably uses a bimetallic strip 3 with the same characteristics and size at the bottom of each heating element 2.

[0056] When the heat dissipation device is working, the coolant flows in from the inlet of one side flow channel 1, enters each parallel flow channel 1 through the diversion structure, cools different heat-generating devices 2, and finally flows out through the outlet through the collection structure. Generally, through fluid dynamics design, the flow resistance of each parallel flow channel 1 is controlled to be the same, so as to achieve uniform flow between the flow channels 1.

[0057] When uneven flow occurs, and the flow rate of one or more channels 1 decreases, the cooling capacity of the heat-generating device 2 at the top of the corresponding channel 1 will decrease. Since the heat-generating devices 2 operate symmetrically and generate similar amounts of heat, the junction temperature of the device at the top of the channel 1 with the reduced flow rate will be significantly higher than the other devices, leading to a higher temperature of the bimetallic strip 3 at its bottom through heat conduction. Simultaneously, due to the similar heat generation of the devices, the coolant temperature in the channel 1 with the lower flow rate will be significantly higher than the coolant temperature in the channel 1 with the higher flow rate, causing the temperature of the bimetallic strip 3 to rise. These two effects work together to cause the temperature of the bimetallic strip 3 to rise towards its fixed end (…). Figure 3 The bimetallic strip 3 bends (upper middle section). This deformation reduces the obstruction of the coolant flow in the flow channel 1 by the bimetallic strip 3, thus reducing the flow resistance of the corresponding flow channel 1. At the same time, the bimetallic strip 3 in the flow channel 1 with a higher flow rate will bend more in the opposite direction to its fixed end (upper middle section). Figure 3 The flow is bent in the direction of the lower side of the channel 1, which increases the obstruction effect on the fluid flow in the channel 1, thereby increasing the flow resistance of the corresponding channel 1. The two work together to achieve a feedback effect, reducing the flow rate in the channel 1 with a high flow rate and increasing the flow rate in the channel 1 with a low flow rate, thus achieving a flow equalization effect. Therefore, the flow equalization effect of the heat dissipation device provided in this application is improved.

[0058] like Figure 4 As shown, the bimetallic strips 3 are arranged sequentially along the coolant flow direction, preferably with adjacent bimetallic strips 3 arranged at equal intervals.

[0059] In another embodiment, a plurality of the thermal bimetallic strips 3 are provided in the same flow channel 1, and the plurality of thermal bimetallic strips 3 form a first metal strip group 3A and a second metal strip group 3B arranged sequentially along the length direction of the flow channel 1; specifically, the first metal strip group 3A and the second metal strip group 3B are each provided with at least two thermal bimetallic strips 3.

[0060] The first metal sheet group 3A and the second metal sheet group 3B are disposed on two opposite walls of the flow channel 1 and projected along the vertical length direction of the flow channel 1. The projections of the first metal sheet group 3A and the second metal sheet group 3B partially or completely overlap.

[0061] like Figure 5 As shown, projected along the length of the vertical flow channel 1, the first metal sheet group 3A and the second metal sheet group 3B are disposed on two opposite walls of the flow channel 1, with the bimetallic strip 3 in the first metal sheet group 3A and the bimetallic strip 3 in the second metal sheet group 3B arranged intersectingly. At this time, the projections of the bimetallic strip 3 in the first metal sheet group 3A and the second metal sheet group 3B partially overlap. Specifically, either the first metal sheet group 3A or the second metal sheet group 3B can be directly opposite the heating device 2 located on the outer wall of the flow channel 1. When the second end of the bimetallic strip 3 bends towards the wall opposite the first end, the flow rate decreases.

[0062] like Figure 9 As shown, projected along the length of the vertical flow channel 1, the first metal sheet group 3A and the second metal sheet group 3B are disposed on two opposite walls of the flow channel 1, and the bimetallic strips 3 in the first metal sheet group 3A and the second metal sheet group 3B are arranged in a one-to-one correspondence. Specifically, preferably, the bimetallic strips 3 in the first metal sheet group 3A and the second metal sheet group 3B have the same structure. At this time, the projections of the bimetallic strips 3 in the first metal sheet group 3A and the second metal sheet group 3B completely overlap.

[0063] Specifically, preferably, the first metal sheet group 3A and the second metal sheet group 3B are located on two opposite sides of the flow channel 1.

[0064] In this application, a series of bimetallic strips 3 are sequentially arranged along the length of the flow channel 1 instead of a single bimetallic strip 3 in the flow equalization structure. These multiple bimetallic strips 3 can be fixed to different side surfaces of the flow channel 1. By using a series connection, a greater flow resistance change can be generated within the same temperature range, thereby achieving a stronger flow equalization effect. Furthermore, staggered arrangement of the bimetallic strips 3 on opposite sides can achieve a greater flow resistance control effect.

[0065] like Figure 6 and Figure 7 As shown, in another embodiment, the heat dissipation device further includes a baffle 8 disposed in each flow channel 1. The baffle 8 is closer to the liquid outlet 5 than the second end of the bimetallic strip 3, and the bimetallic strip 3 and the baffle 8 are disposed on two opposite walls of the flow channel 1. The baffle 8 protrudes from its wall surface, thereby reducing the cross-sectional area at the location of the baffle 8.

[0066] In one specific embodiment, the first end of the baffle 8 is connected to the flow channel 1, and the second end of the baffle 8, away from the first end, is inclined towards the liquid inlet 4. Of course, in actual use, the baffle 8 can also be arranged perpendicular to the direction of the coolant in the flow channel 1.

[0067] Specifically, the baffle 8 is fixed to the inner wall of the flow channel 1. To improve assembly efficiency, the baffle 8 can be integrally formed with the flow channel 1.

[0068] Since the heat dissipation effect of the heat dissipation device in this application is closely related to the sensitivity of the flow resistance of each flow channel 1 to the device's junction temperature, a better effect is achieved by using a flow channel 1 structure in conjunction with the baffle 8 and the thermal bimetallic strip 3. A reverse-protruding structure is added behind the thermal bimetallic strip 3 to facilitate flow control. When the device junction temperature is high, the thermal bimetallic strip 3 adheres to the upper surface of the flow channel 1, and the coolant can directly bypass the rear reverse-protruding structure. However, when the device junction temperature is low, the thermal bimetallic strip 3 bends downwards, causing the coolant to bypass the thermal bimetallic strip 3 from the bottom and then reverse upwards to bypass the rear baffle structure. This distortion and elongation of the flow line causes a sharp increase in the flow resistance of the flow channel 1, thereby improving the flow uniformity effect.

[0069] Based on the above scheme, preferably, the second end of the thermal bimetallic strip 3 is closer to the liquid outlet 5 than the first end of the thermal bimetallic strip 3.

[0070] Multiple hot bimetallic strips 3 are provided in the same flow channel 1, and the first end of the hot bimetallic strip 3 is closer to the liquid outlet 5 than the second end of the hot bimetallic strip 3.

[0071] Alternatively, the first end of the bimetallic strip 3 can be positioned away from the liquid inlet 4 relative to the second end of the bimetallic strip 3. In specific assembly, the bimetallic strip 3 can be arranged in either of the above two ways within the flow channel 1.

[0072] like Figure 9 As shown, in one specific embodiment, multiple hot bimetallic strips 3 may be provided in the same flow channel 1, and hot bimetallic strips 3 may be provided on two opposite sides of the flow channel 1, with the first end of the hot bimetallic strip 3 being closer to the liquid outlet 5 than the second end of the hot bimetallic strip 3.

[0073] like Figure 8 and Figure 9 As shown, the dashed lines represent the flow lines of the internal coolant. It can be seen that when the bimetallic strip 3 bends downwards, its turbulent effect causes the coolant to generate a reverse vortex, leading to severe internal friction, increased flow resistance, and thus increased sensitivity of the flow resistance of channel 1 to the device's temperature. However, this design places high demands on the rigidity of the bimetallic strip 3. A high-rigidity bimetallic strip 3 must be used, or the design must ensure that the bimetallic strip 3 only covers a portion of the width of channel 1 to prevent it from blocking the channel 1 due to fluid pressure and becoming self-locking, or from undergoing plastic deformation under fluid pressure.

[0074] The bimetallic strip 3 can also be fixed to the surface of the non-heating device 2 inside the flow channel 1, such as the lower surface of the flow channel 1 or the inner surface of the flow channel 1, thereby increasing the freedom in terms of process and layout. In this case, the bimetallic strip 3 can only sense the temperature of the coolant inside the flow channel 1, and cannot directly sense the increase in surface temperature of the flow channel 1 caused by the increase in the device's junction temperature, so the flow equalization effect will be reduced to some extent.

[0075] like Figure 10 As shown, when there are turbulence structures (such as fins, corrugated plates, and pin fins) within the bottom flow channel 1 of the device to enhance heat transfer, making it impossible to arrange a flow equalization structure, the bimetallic strip 3 is positioned downstream of the heating element 2 on the power electronic device, i.e., along the fluid direction within the flow channel 1, the bimetallic strip 3 is located downstream of the heating element 2. This achieves automatic flow equalization in the flow channel 1 by arranging a flow equalization structure behind the heating element 2. In this case, the bimetallic strip 3 cannot directly sense changes in the device's junction temperature; it mainly achieves flow equalization by sensing changes in the coolant temperature within the flow channel 1 caused by poor flow equalization.

[0076] To improve heat dissipation efficiency, in another embodiment, multiple bimetallic strips 3 are provided within the same flow channel 1, and the multiple bimetallic strips 3 are disposed on the same side of the inner wall of the flow channel 1. Specifically, some or all of the bimetallic strips 3 in each flow channel 1 and the heat-generating device 2 on the power electronic device may be disposed on the inner and outer walls of the same side of the flow channel 1 and arranged opposite to each other.

[0077] The bimetallic strip 3 provided in this application provides varying flow resistance in the flow channel 1, thus requiring it to have a certain force-bearing capacity. The deformation of the bimetallic strip 3 in the system is the result of the combined effect of temperature and fluid pressure. Therefore, during the design phase, factors such as the required change in flow resistance and the flow velocity within the flow channel 1 must be comprehensively considered when designing the material, shape, and dimensions of the bimetallic strip 3 to ensure it has sufficient strength and can generate a sufficient change in flow resistance within the flow channel 1 within the required temperature range.

[0078] The bimetallic strip 3 can be fixed to the heat sink by welding, bonding, bolting, etc. It needs to be tightly and reliably connected to the inner wall of the flow channel 1 to prevent loosening due to vibration, thermal expansion, etc. during use.

[0079] The heat dissipation device of this application can also automatically adapt to special operating conditions where symmetrically arranged components generate uneven heat. Under certain special operating conditions, electronic products may exhibit situations where some components generate a lot of heat, while others generate very little heat, and the heat distribution may change over time. In such cases, we hope that the flow distribution between each parallel flow channel 1 can change with the operating conditions, automatically increasing the flow rate of the corresponding cooling flow channel 1 when some components generate severe heat to ensure a good cooling effect. When the heat generated by the device corresponding to one or more parallel flow channel branches 1 is high, while the heat generated by the devices corresponding to other flow channel branches 1 is low, the heat sink wall temperature and liquid temperature in the high-heat-generating flow channel branch 1 will be higher than those in the low-heat-generating flow channel branch 1. This, through the aforementioned deformation of the bimetallic strip 3, results in lower flow resistance in the high-heat-generating flow channel branch 1 and higher flow resistance in the low-heat-generating flow channel branch 1. This achieves the effect of automatically concentrating the coolant flow rate in the high-heat-generating flow channel branch 1, completing the adaptation to special operating conditions. Specifically, it can automatically adapt to changes in the thermal characteristics of the chip itself and changes in operating conditions, while reducing the impact of processing and design errors on the flow uniformity between flow channels 1, achieving better flow uniformity. Because the heat dissipation device of this application automatically adapts to the instantaneous heat generation non-uniformity caused by changes in the operating conditions and working states of the heat-generating device 2, the heat dissipation device of this invention can effectively improve the internal temperature uniformity of electronic products, thereby improving the system's operational stability and reliability.

[0080] Meanwhile, the heat dissipation device provided in this application can automatically adjust when contaminants clog the flow channel 1, achieving a self-cleaning effect through flushing. When an individual flow channel 1 is blocked by contaminants, the flow rate of that flow channel 1 will decrease significantly, resulting in an increase in the internal wall temperature and liquid temperature. This, in turn, will increase the flow rate of the corresponding flow channel 1 through the flow resistance modulation effect of the thermal bimetallic strip 3. Under continuous flushing with a relatively large flow rate, it is possible to break up or move the blocking contaminants, thus completing the self-cleaning of the flow channel 1.

[0081] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0082] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A heat dissipating device, characterized by, For heat dissipation of electronic devices, including liquid inlet (4), liquid outlet (5), flow channel (1) and thermal bimetallic strip (3). The number of flow channels (1) is one or more. When there are multiple flow channels (1), the multiple flow channels (1) are arranged in parallel between the liquid inlet (4) and the liquid outlet (5). Each flow channel (1) includes an inlet section (6) and an outlet section (7). No heating device (2) is provided at the inlet section (6) and it is connected to the liquid inlet (4). At least one heating device (2) is provided at the outlet section (7) and it is connected to the liquid outlet (5). One or more of the thermal bimetallic strips (3) are provided in each of the flow channels (1). The first end of the thermal bimetallic strip (3) is connected to the inner wall of the outlet section (7) of the flow channel (1). The second end of the thermal bimetallic strip (3) is a free end, and the second end is bent away from the wall of the flow channel (1) where the first end is located relative to the first end. Multiple thermal bimetallic strips (3) are provided in the same flow channel (1), and the multiple thermal bimetallic strips (3) form a first metal strip group (3A) and a second metal strip group (3B) arranged sequentially along the length direction of the flow channel (1). The first metal sheet group (3A) and the second metal sheet group (3B) are disposed on two opposite walls of the flow channel (1) and projected along the vertical length direction of the flow channel (1). The projections of the first metal sheet group (3A) and the second metal sheet group (3B) partially or completely overlap.

2. The heat dissipating device according to claim 1, wherein The thermal bimetallic strip (3) is provided on the side of the flow channel (1) near the heating device (2), and the back side of the first end of the thermal bimetallic strip (3) on the flow channel (1) is used to set the heating device (2).

3. The heat dissipating device according to claim 2, wherein The second end of the thermal bimetallic strip (3) is closer to the liquid outlet (5) than the first end of the thermal bimetallic strip (3).

4. The heat dissipating device of claim 2, wherein Multiple thermal bimetallic strips (3) are provided in the same flow channel (1), and the multiple thermal bimetallic strips (3) are disposed on the same side of the inner wall of the flow channel (1).

5. The heat dissipating device of claim 4, wherein Multiple thermal bimetallic strips (3) are provided in the same flow channel (1), and the first end of the thermal bimetallic strip (3) is closer to the liquid outlet (5) than the second end of the thermal bimetallic strip (3).

6. The heat dissipating device of claim 1, wherein Multiple thermal bimetallic strips (3) are provided in the same flow channel (1). The thermal bimetallic strips (3) are provided on two opposite sides of the flow channel (1), and the first end of the thermal bimetallic strip (3) is closer to the liquid outlet (5) than the second end of the thermal bimetallic strip (3).

7. The heat dissipating device of claim 1, wherein It also includes a baffle (8) disposed in each of the flow channels (1), the baffle (8) being closer to the outlet (5) than the second end of the hot bimetallic strip (3), and the hot bimetallic strip (3) and the baffle (8) being disposed on two opposite walls of the flow channel (1), the baffle (8) protruding on its own wall.

8. The heat dissipation device according to claim 7, characterized in that, The first end of the turbulence-disrupting element (8) is connected to the flow channel (1), and the second end of the turbulence-disrupting element (8) away from the first end is inclined toward the liquid inlet (4).

9. The heat dissipation device according to any one of claims 1-8, characterized in that, The passive layer alloy of the thermal bimetallic sheet (3) is Invar alloy, and the active layer alloy is manganese copper nickel alloy. And / or, The bimetallic strip (3) is rectangular in shape. The width of the bimetallic strip (3) is the same as the width of a single flow channel (1). One end of the bimetallic strip (3) along its length is fixed to the wall of the flow channel (1), and the other end is a free end. Alternatively, one end of the bimetallic strip (3) along its width is fixed to the wall of the flow channel (1), and the other end is a free end.

10. The heat dissipating device of claim 9, wherein, The length of the bimetallic strip (3) is designed such that, under rated operating temperature, the bending amount of the bimetallic strip (3) causes the free end to bend up to 70% of the depth of the flow channel (1); when the temperature increases by 40°C compared to the rated operating temperature, the bending curvature of the bimetallic strip (3) becomes 0.

Images