Heat pipe and heat pipe radiator

Abstract

The utility model relates to a heat pipe and a heat pipe radiator. The heat pipe comprises a first pipe body and a second pipe body, a first capillary structure layer is arranged on the inner wall of the first pipe body, a first working medium layer is arranged in the first capillary structure layer, one end of the first pipe body is a first evaporation end, and the other end of the first pipe body is a first cooling end; a second capillary structure layer is arranged on the inner wall of the second pipe body, a second working medium layer is arranged in the second capillary structure layer, one end of the second pipe body is a second evaporation end, and the other end of the second pipe body is a second cooling end; the first cooling end of the first pipe body extends into the second evaporation end of the second pipe body, and the boiling point of the first working medium layer is higher than that of the second working medium layer. The first pipe body and the second pipe body are combined into a whole, the overall length of the heat pipe is increased, and the heat pipe is suitable for heat dissipation of large-size electronic equipment. As the boiling point of the second working medium is lower, evaporation and heat absorption can be performed at a lower temperature, and the heat transfer efficiency is ensured.

Description

Technical Field

[0001] The utility model belongs to the field of heat pipes, in particular to a heat pipe and a heat pipe radiator. Background Art

[0002] Heat pipe is a very common heat-conducting pipe, which is often used for heat dissipation of electronic equipment. One end of the heat pipe is the evaporation end, and the other end is the cooling end. A porous capillary structure layer is set on the inner wall of the heat pipe. The inside of the heat pipe is evacuated, and a liquid working medium is set inside. The liquid working medium can be absorbed by the capillary structure layer. During operation, the evaporation end absorbs heat, and the liquid working medium at the evaporation end evaporates into gas and flows to the cooling end. The working medium liquefies and releases heat at the cooling end to achieve heat transfer. After the working medium is liquefied, it returns to the evaporation end along the capillary structure layer under the capillary action of the capillary structure layer to achieve circulation.

[0003] Theoretically, when the heat pipe is operating, the height of the working fluid liquid level should just cover the capillary structure layer at the evaporation end. If the working fluid is filled too much, the working fluid liquid level is high, submerging the capillary structure layer, and the steam cannot quickly escape from the working fluid liquid level, which affects the flow of the working fluid and increases the thermal resistance. When the heat pipe is longer, more working fluid is required, and the working fluid may accumulate at the evaporation end, causing the evaporation end liquid level to be too high, affecting the heat transfer efficiency. Therefore, the current heat pipe length is generally relatively small, usually not exceeding 300mm. When the electronic equipment is large in size, the distance between the heat source and the cooling end is large, and the heat pipe length may be insufficient.

[0004] The utility model patent with application number CN202110339865.0 discloses a heat pipe, an electronic device and a processing method of a heat pipe, including a tube body, and the heat pipe also includes a barrier structure arranged in the tube body, the barrier structure separates the tube body into a first tube section and a second tube section, the first liquid medium flow channel in the first tube section and the second liquid medium flow channel in the second tube section are mutually blocked, and the first gas medium flow channel in the first tube section and the second gas medium flow channel in the second tube section are interconnected. When in use, the evaporation end of one of the tube sections is located at the heat source, and the heat source can be a heat-generating element of an electronic device. However, due to the increase in the length of the heat pipe, there is a certain distance between the barrier component and the heat source, and the temperature of the evaporation end of the other tube section is lower than the temperature of the heat source, resulting in a slower evaporation rate of the working fluid at the evaporation end of the other tube section, affecting the heat dissipation efficiency. Therefore, a heating element is arranged at the barrier structure, which increases energy consumption, and the heating element generates new heat, which is obviously not conducive to heat dissipation. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a heat pipe and a heat pipe radiator, which can increase the length of the heat pipe and ensure the heat dissipation efficiency.

[0006] In order to solve the above problems, the technical solution adopted by the utility model is as follows: a heat pipe comprises a first tube body and a second tube body;

[0007] The inner wall of the first tube body is provided with a first capillary structure layer, the first capillary structure layer is provided with a first working medium layer, and one end of the first tube body is a first evaporation end, and the other end is a first cooling end;

[0008] The inner wall of the second tube body is provided with a second capillary structure layer, the second working medium layer is provided in the second capillary structure layer, and one end of the second tube body is a second evaporation end, and the other end is a second cooling end;

[0009] The outer diameter of the first tube body is smaller than the inner diameter of the second tube body, the length of the first tube body is smaller than the length of the second tube body, the first cooling end of the first tube body extends into the second evaporation end of the second tube body, and the first tube body is coaxial with the second tube body, and the boiling point of the first working fluid layer is higher than the boiling point of the second working fluid layer.

[0010] Furthermore, the first tube body and the second tube body are copper tubes.

[0011] Furthermore, the first working fluid layer is water, and the second working fluid layer is methanol, ethanol or acetone.

[0012] Furthermore, a third capillary structure layer is provided on the outer wall of a portion of the first cooling end located inside the second evaporation end.

[0013] Furthermore, a flexible positioning membrane is provided on the bottom wall of the first evaporation end, a storage cavity is provided between the positioning membrane and the bottom wall of the first evaporation end, a third working fluid layer is provided in the storage cavity, and the boiling point of the third working fluid layer is higher than that of the first working fluid layer; a flexible liquid absorption layer is provided on the outer wall of the positioning membrane, and a rigid filter screen is provided on the outer side of the positioning membrane.

[0014] Furthermore, the third working fluid layer is toluene.

[0015] Furthermore, the thickness of the liquid absorbing layer is 3 to 4 mm.

[0016] A heat pipe radiator comprises the above-mentioned heat pipe.

[0017] The beneficial effects of the utility model are as follows: 1. The utility model combines the first tube body and the second tube body into one body, and the overall length of the heat pipe is increased, which is suitable for heat dissipation of large-volume electronic equipment.

[0018] 2. When the utility model is used, the first evaporation end of the first tube body is set near the heat source of the electronic device, and the second cooling end of the second tube body is set at a position away from the heat source. Since there is a certain distance between the second evaporation end of the second tube body and the heat source, the temperature at the second evaporation end is lower than the temperature of the first evaporation end. The first working fluid is filled into the first tube body, and the first medium becomes the first working fluid layer after being absorbed by the first capillary structure layer. The second working fluid is filled into the second tube body, and the second medium becomes the second working fluid layer after being absorbed by the second capillary structure layer. Since the boiling point of the second working fluid is lower than that of the first working fluid, the second working fluid can evaporate and absorb heat at a lower temperature. When the temperature of the second evaporation end is lower than that of the first evaporation end, it can also evaporate quickly and absorb heat to ensure the heat transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional schematic diagram of the heat pipe of the utility model;

[0020] Figure 2 yes Figure 1 A magnified schematic diagram of part A;

[0021] Figure 3 yes Figure 2 A magnified schematic diagram of part B;

[0022] Figure numerals: 1—first tube body; 2—second tube body; 3—first capillary structure layer; 4—first evaporation end; 5—first cooling end; 6—second capillary structure layer; 7—second evaporation end; 8—second cooling end; 9—third capillary structure layer; 10—positioning membrane; 11—third working fluid layer; 12—liquid absorption layer; 13—rigid filter. DETAILED DESCRIPTION

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0024] The heat pipe of the utility model is as follows Figures 1 to 3 As shown, it includes a first tube body 1 and a second tube body 2. The first tube body 1 and the second tube body 2 are both circular pipes, which can be made of copper pipes or stainless steel pipes and other materials with high thermal conductivity.

[0025] The inner wall of the first tube body 1 is provided with a first capillary structure layer 3, a first working medium layer is provided in the first capillary structure layer 3, and one end of the first tube body 1 is a first evaporation end 4, and the other end is a first cooling end 5. The first working medium is filled into the first tube body 1, and after being absorbed by the first capillary structure layer 3, the first working medium layer is formed.

[0026] The inner wall of the second tube body 2 is provided with a second capillary structure layer 6, a second working medium layer is provided in the second capillary structure layer 6, and one end of the second tube body 2 is a second evaporation end 7, and the other end is a second cooling end 8. The second working medium is filled into the second tube body 2, and after being absorbed by the second capillary structure layer 6, it becomes a second working medium layer.

[0027] The first capillary structure layer 3 and the second capillary structure layer 6 may be made by using existing technology, for example, by sintering copper powder.

[0028] The outer diameter of the first tube body 1 is smaller than the inner diameter of the second tube body 2, the length of the first tube body 1 is smaller than the length of the second tube body 2, the first cooling end 5 of the first tube body 1 extends into the second evaporation end 7 of the second tube body 2, and the first tube body 1 is coaxial with the second tube body 2, and the boiling point of the first working fluid layer is higher than the boiling point of the second working fluid layer.

[0029] The first cooling end 5 of the first tube body 1 extends into the second evaporation end 7 of the second tube body 2, and the second evaporation end 7 of the second tube body 2 can absorb the heat of the first cooling end 5, so that the first working medium in the first cooling end 5 is liquefied. The first tube body 1 and the second tube body 2 are coaxially arranged, and there is an appropriate distance between the outer wall of the first cooling end 5 and the inner wall of the second evaporation end 7, so that the second working medium on the inner wall of the second evaporation end 7 has enough circulation space after evaporation.

[0030] The working process of the heat pipe of the utility model is as follows: the first evaporation end 4 of the first tube body 1 is set near the heat source of the electronic device, and the heat source can be a component with high heat generation such as the main board of the electronic device, and the second cooling end 8 of the second tube body 2 is set at a relatively low temperature position, such as the housing of the electronic device. The heat generated by the heat source is absorbed by the first working fluid inside the first evaporation end 4, the first working fluid evaporates into gaseous state, and then flows along the inner cavity of the first tube body 1 to the first cooling end 5, the second working fluid in the second evaporation end 7 absorbs the heat of the first cooling end 5 and evaporates and gasifies, the first working fluid in the first cooling end 5 releases heat and liquefies, and returns to the first evaporation end 4 along the first capillary structure layer 3; after the second working fluid evaporates, it flows along the inner cavity of the second tube body 2 to the second cooling end 8, and then releases heat and liquefies at the second cooling end 8, and finally returns to the second evaporation end 7 through the second capillary structure layer 6.

[0031] The utility model integrates the first tube body 1 and the second tube body 2 into one body, so that the length of the entire heat pipe is increased, and is suitable for heat dissipation of large or integrated electronic equipment, such as server units, data centers, etc.

[0032] Since there is a certain distance between the second evaporation end 7 of the second tube body 2 and the heat source, the temperature at the second evaporation end 7 is lower than the temperature at the first evaporation end 4. The utility model fills the second working medium with a boiling point lower than the first working medium in the second tube body 2, so that the second working medium can evaporate and absorb heat at a lower temperature. When the temperature of the second evaporation end 7 is lower than the temperature of the first evaporation end 4, it can also evaporate quickly and absorb heat, thereby ensuring the heat transfer efficiency.

[0033] The heat pipe can be a low-temperature heat pipe, a normal temperature heat pipe, and a high-temperature heat pipe, and the first working fluid and the second working fluid can be selected according to the application environment of the heat pipe. The heat pipe of the utility model is a normal temperature heat pipe, the first working fluid is water, and the second working fluid is methanol, ethanol or acetone. It is well known that among normal temperature working fluids, water is the working fluid with the highest specific heat capacity. When the temperature is raised by the same amount, the heat absorbed by water is more than the heat absorbed by methanol, ethanol or acetone. When the outer diameter of the first tube body 1 is smaller than the inner diameter of the second tube body 2, the length of the first tube body 1 should also be smaller than the length of the second tube body 2 to ensure thermal efficiency. Therefore, the volume of the inner cavity of the first tube body 1 is smaller than the volume of the inner cavity of the second tube body 2, and the first working fluid filled in the first tube body 1 is less than the second working fluid filled in the second tube body 2. Under ideal conditions, the heat transfer amount of the first tube body 1 and the heat transfer amount of the second tube body 2 should be the same. In order to achieve this heat transfer effect, in the utility model, the first working fluid is water, and the second working fluid is methanol, ethanol or acetone. The filling amount of water is less than the filling amount of methanol, ethanol or acetone. The evaporation amount of the second working fluid is greater than the evaporation amount of the first working fluid. However, due to the difference in specific heat capacity, the heat absorption amount of the first evaporation end can be close to the heat absorption amount of the second evaporation end, thereby achieving effective heat transfer.

[0034] The outer wall of the portion of the first cooling end 5 located inside the second evaporation end 7 is provided with a third capillary structure layer 9. The third capillary structure layer 9 is the same as the second capillary structure layer 6 and can also absorb the second working fluid. The third capillary structure layer 9 and the second working fluid of the second evaporation end 7 evaporate and absorb heat at the same time, which can increase the evaporation area of ​​the second working fluid and accelerate the heat dissipation efficiency.

[0035] Generally speaking, the amount of the first working fluid filled in the first tube body 1 should be appropriate. If there is too much first working fluid, it will cause the first working fluid to submerge the first capillary structure layer 3 in the first evaporation end 4. After the first working fluid evaporates into gas, it cannot quickly leave the working fluid liquid surface, thereby increasing thermal resistance; if there is too little first working fluid, as the first working fluid evaporates and the external temperature rises, the first working fluid liquid level in the first capillary structure layer 3 gradually decreases. When the heat source releases a large amount of heat, the first working fluid liquid level in the first capillary structure layer 3 eventually decreases to zero, forming a local dry-out in the evaporation section, and the heat dissipation efficiency decreases rapidly. In order to ensure that the heat pipe can withstand a higher maximum thermal power, it is best to supplement the first working fluid when the thermal power is high, and reduce the first working fluid involved in the circulation when the thermal power is low. The utility model patent application CN202410032910.1 filed by the applicant on January 10, 2024 discloses a heat pipe, a radiator and an electronic device, wherein the end of the evaporation section of the heat pipe is sealed by an end plate, a support mesh tube is fixedly arranged on the end plate, a spacing is provided between the support mesh tube and the capillary structure layer, a permeable membrane is arranged on the inner wall of the support mesh tube, a thermosensitive deformation column is arranged inside the permeable membrane, and a salt solution is filled between the thermosensitive deformation column and the permeable membrane. When the thermal power of the heat pipe is high, the temperature of the evaporation section is high, at which time the thermosensitive deformation column expands due to the heat, increases in volume, and squeezes the salt solution in the permeable membrane. Under the action of pressure, the water in the salt solution flows through the permeable membrane to the outside of the permeable membrane, is absorbed by the capillary structure layer, and replenishes the working fluid to the capillary structure layer. When the heat pipe's thermal power is reduced, the fluid level of the capillary structure layer 4 rises, and the excess fluid overflows the capillary structure layer. At the same time, the temperature of the thermosensitive deformation column decreases, and the volume decreases. Under the effect of the concentration difference, the fluid outside the permeable membrane will pass through the permeable membrane into the inside of the permeable membrane, reducing the fluid level of the capillary structure layer. Subsequent studies have found that the thermosensitive deformation column has a small deformation amount, a small increase in volume, and less water can be squeezed out.

[0036] In the utility model, Figure 3 As shown, a flexible positioning film 10 is provided on the bottom wall of the first evaporation end 4, a storage cavity is provided between the positioning film 10 and the bottom wall of the first evaporation end 4, a third working medium layer 11 is provided in the storage cavity, and the boiling point of the third working medium layer 11 is higher than that of the first working medium; a flexible liquid absorption layer 12 is provided on the outer wall of the positioning film 10, and a rigid filter screen 13 is provided on the outer side of the positioning film 10. The third working medium is filled into the storage cavity to obtain the third working medium layer.

[0037] The positioning membrane 10 can be made of a material with a certain strength and capable of withstanding a temperature above 150 degrees, such as a polytetrafluoroethylene membrane and a polyetheretherketone membrane. The third working medium layer 11 is always in the storage cavity and is not mixed with the first working medium. The liquid absorption layer 12 can be made of a commonly used flexible water-absorbing material such as a sponge. The liquid absorption layer 12 can absorb a certain amount of the first working medium, thereby increasing the amount of the first working medium. The rigid filter 13 can be made of a stainless steel wire mesh, etc.

[0038] Since the boiling point of the third working medium layer 11 is higher than that of the first working medium, when the temperature outside the first evaporation end 4 is not high, the third working medium layer 11 remains in liquid state, the first working medium in the first capillary structure layer 3 works, and only a small amount of the first working medium in the liquid absorption layer 12 is evaporated, and most of it remains in the liquid absorption layer 12. As the temperature outside the first evaporation end 4 rises, the liquid level of the first working medium in the first capillary structure layer 3 gradually drops, and at the same time, the third working medium layer 11 begins to evaporate into gaseous state, and the volume expands, prompting the positioning film 10 to open, pushing the liquid absorption layer 12 on the outer wall of the positioning film 10 to squeeze the rigid filter screen 13. After the liquid absorption layer 12 is squeezed, the first working medium inside is squeezed out and flows through the holes of the rigid filter screen 13 to the first capillary structure layer 3 of the first evaporation end 4, replenishing the first working medium to the first capillary structure layer 3. When the temperature outside the first evaporation end 4 decreases, the third working medium layer 11 liquefies and its volume decreases, causing the positioning membrane 10 to shrink and the liquid absorption layer 12 to leave the rigid filter screen 13 . The first working medium accumulated inside the first evaporation end 4 is reabsorbed by the liquid absorption layer 12 , reducing the working medium in the first capillary structure layer 3 .

[0039] In the present invention, the third working medium layer 11 is made of toluene.

[0040] The thicker the liquid absorption layer 12 is, the more first working fluid it can absorb. As a preferred embodiment of the present invention, the thickness of the liquid absorption layer 12 is 3 to 4 mm.

[0041] The heat pipe radiator of the utility model comprises: Figures 1 to 3 Heat pipe shown.

[0042] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A heat pipe, characterized in that: It includes a first pipe body (1) and a second pipe body (2); The inner wall of the first tube body (1) is provided with a first capillary structure layer (3), a first working medium layer is provided inside the first capillary structure layer (3), and one end of the first tube body (1) is a first evaporation end (4), and the other end is a first cooling end (5); The inner wall of the second tube body (2) is provided with a second capillary structure layer (6), a second working medium layer is provided inside the second capillary structure layer (6), and one end of the second tube body (2) is a second evaporation end (7), and the other end is a second cooling end (8); The outer diameter of the first tube body (1) is smaller than the inner diameter of the second tube body (2), the length of the first tube body (1) is smaller than the length of the second tube body (2), the first cooling end (5) of the first tube body (1) extends into the second evaporation end (7) of the second tube body (2), the first tube body (1) and the second tube body (2) are coaxial, and the boiling point of the first working fluid layer is higher than the boiling point of the second working fluid layer.

2. The heat pipe according to claim 1, characterized in that: The first tube body (1) and the second tube body (2) are copper tubes.

3. The heat pipe according to claim 2, characterized in that: The first working fluid layer is water, and the second working fluid layer is methanol, ethanol or acetone.

4. The heat pipe according to claim 1, characterized in that: The outer wall of the portion of the first cooling end (5) located inside the second evaporation end (7) is provided with a third capillary structure layer (9).

5. The heat pipe according to claim 1, 2, 3 or 4, characterized in that: The bottom wall of the first evaporation end (4) is provided with a flexible positioning membrane (10), a storage cavity is provided between the positioning membrane (10) and the bottom wall of the first evaporation end (4), a third working fluid layer (11) is provided in the storage cavity, and the boiling point of the third working fluid layer (11) is higher than that of the first working fluid layer; the outer wall of the positioning membrane (10) is provided with a flexible liquid absorption layer (12), and the outer side of the positioning membrane (10) is provided with a rigid filter screen (13), and the rigid filter screen (13) is provided.

6. The heat pipe according to claim 5, characterized in that: The third working fluid layer (11) is toluene.

7. The heat pipe according to claim 5, characterized in that: The thickness of the liquid absorbing layer (12) is 3 to 4 mm.

8. Heat pipe radiator, characterized in that: Comprising the heat pipe according to claim 1.

Images