TWI405944B - Heat dissipation device - Google Patents

Abstract

The present invention relates to a heat dissipation device, including: an outer pipe; an inner pipe disposed in the outer pipe and having a plurality of openings at two terminal walls thereof to allow the first chamber to communicate with the second chamber, an internal space of the inner pipe being served as a first chamber and a space between the inner pipe and the outer pipe being served as a second chamber; and a magnetic nanofluid filled in the first chamber and the second chamber and including a liquid fluid and a plurality of magnetic nanoparticles. Accordingly, the heat dissipation of the present invention can exhibit improved heat transfer performance and has advantages of simple structure and small size.

Description

Heat sink

The invention relates to a heat dissipating device, in particular to a heat dissipating device suitable for effectively discharging waste heat.

In the current heat dissipation market, heat pipes have become the most widely used technology because of their excellent heat transfer performance, and are widely used in various heat dissipation systems. Increasing the heat transfer characteristics of heat pipes is the focus of today's heat pipe development, and the main research directions are: changing the heat pipe structure and changing the working fluid.

In terms of working fluids, the recent research trend of nanofluidic systems has suspended nanometer-sized metallic or non-metallic nanoparticles in fluids to alter the basic flow and heat transfer characteristics of fluids without the addition of large particles. The problem of channel blockage and pressure drop caused by the fluid. Conventionally used nanometer fluid particles mainly include: metal nanoparticles such as gold, silver, copper; oxide nanoparticles such as alumina, copper oxide, ceria; and carbon nanotubes. In addition, it has also been proposed to use a magnetic nanofluid as a working fluid, among which various magnetic nanoparticle preparation methods have been proposed, such as the superparamagnetic particles disclosed in Taiwan Patent No. TW096116233, however, magnetic nanoparticles are applied. There is still room for improvement in the cooling system. On the other hand, as far as the heat pipe structure is concerned, the heat pipes currently used mainly include: a single pipe heat pipe, a loop heat pipe, and a loop pulse heat pipe.

As shown in FIG. 1A, the conventional single-tube heat pipe is composed of a closed pipe body 11, the inner wall of which is covered with a capillary structure 13, and a working fluid 14 is disposed inside. Accordingly, as shown in FIG. 1A, when the working fluid 14 of the evaporation portion B1 of the single-tube heat pipe is heated and vaporized, the vaporized vapor phase moves toward the condensation portion B2 (as indicated by the arrow), and is in the condensation portion B2. The gas phase is condensed into a liquid phase, and the condensed liquid phase will flow back to the evaporation portion B1 by the capillary force of the capillary structure 13 (as indicated by the arrow). In the single-tube heat pipe, since the vaporization gas phase and the condensate flow in the same flow channel, the vapor having a large flow velocity easily shears the condensate, so that the condensate cannot flow back to the vapor portion, thereby causing the evaporation portion to dry. The phenomenon of burning. In addition, if the working fluid used in the single-tube heat pipe is a nanofluid, the solid-gas phase separation occurring during evaporation causes the nanoparticles to remain in the evaporation portion, which in turn causes an increase in thermal resistance.

Japanese Patent No. JP57108593 discloses a heat dissipation device for a single-tube heat pipe filled with a magnetic fluid, which uses an electromagnetic coil wound around a heat pipe to accelerate the speed of the magnetic fluid, but since the vapor phase and the condensate still flow in the same flow path, Therefore, the vapor is still likely to hinder the flow of the condensate back to the evaporation portion, and the solid-gas phase separation phenomenon occurring during evaporation tends to leave the magnetic particles in the evaporation portion, resulting in an increase in thermal resistance.

In order to solve the problem that the above-mentioned evaporation part is easy to dry, another technique of a loop type heat pipe is proposed. As shown in FIG. 1B, the conventional loop heat pipe performs heat exchange between the evaporation portion B1 and the condensation portion B2 by the working fluid 24 in the closed circuit tube 21, wherein the evaporation gas phase and the condensate flow in different flow paths. Therefore, the problem that the vapor can cause shearing force to the condensate and the condensate cannot flow back to the vapor portion can be avoided.

On the other hand, in order to solve the problem of separating the above-mentioned nanoparticle from the gas phase, a technique of a loop pulse type heat pipe has been proposed. As shown in FIG. 1C, the conventional loop pulse type heat pipe is mainly a multi-circuit type pipe body 31 composed of a plurality of heat pipes connected in series, wherein the working fluid 34 can form a gas phase and a nano fluid in the multi-circuit type pipe body 31. The transfer unit prevents the nanoparticles from remaining in the evaporation portion B1. However, the conventional loop pulse type heat pipe has the disadvantages of complicated structure and large space occupation.

In addition, Japanese Patent No. JP57096557, Japanese Patent No. JP8014779, and Taiwan Patent No. TW097145608 disclose a technique for removing heat by flowing a working fluid in a double-pipe split structure, wherein, in order to increase the heat conductivity effect, the contact area is increased. It has a number of baffles or fins to allow the working fluid to exchange heat. However, this structure may cause the working fluid flow rate to slow down, but it may not achieve the purpose of rapid heat dissipation. In particular, if the structure uses a nanofluid as a working fluid, the thermal resistance may increase due to gas-solid separation.

The object of the present invention is to provide a heat dissipating device, which can improve heat dissipation efficiency, and has the advantages of simple structure and no space occupation.

In order to achieve the above object, the present invention provides a heat dissipating device comprising: an outer tube; an inner tube disposed in the outer tube, wherein the inner space of the inner tube constitutes a first cavity, and the inner tube and the inner tube The space between the outer tubes constitutes a second cavity, and the end walls of the inner tube have a plurality of openings for interconnecting the first cavity and the second cavity; and a magnetic nanofluid Filled in the first cavity and the second cavity, wherein the magnetic nanofluid comprises a liquid fluid and a plurality of magnetic nanoparticles.

Accordingly, the present invention uses a double-tube heat pipe structure to flow the vaporized gas phase of the working fluid (ie, magnetic nanofluid) and the high-temperature liquid phase and the condensate in different flow paths to avoid the conventional single-tube heat pipe. The problem of dry burning in the evaporation department that is prone to occur. Here, when the magnetic nano-filled fluid filled in the heat-dissipating device of the present invention is heated, the liquid fluid can be transferred by heat transfer by evaporation and condensation to achieve the effect of rapidly transferring heat; in addition, The collision between particles and particles in the rice fluid and the collision of the particles with the tube wall to effectively improve the heat transfer effect. In particular, in the heat dissipating device of the present invention, the end walls of the inner tube are formed with openings similar to those of the nozzle, so that the magnetic nano-fluid can form a gas-liquid phase coexisting transmission unit when heated, so as to avoid the conventional single-tube heat pipe. It is prone to the problem that the thermal retention of the particles is caused by the indwelling of the particles, and the thermal contact effect can be exhibited without increasing the contact area or adding baffles or fins. The contact area can be increased or the baffles or fins can be added. The problem of slowing the flow rate of the working fluid is to achieve rapid heat dissipation. Compared with the conventional loop pulse type heat pipe, the heat dissipating device of the invention can exhibit excellent heat transfer characteristics, and has the advantages of simple structure, low manufacturing cost and small volume.

The heat dissipating device of the present invention may further comprise: a capillary structure covering the inner wall of the first cavity or the second cavity. Accordingly, in addition to the action of gravity, the condensed liquid fluid can be quickly returned to the evaporation portion by capillary action to improve heat transfer efficiency.

The heat dissipating device of the present invention may further comprise: a magnetic field generating unit disposed in a periphery of the inner tube or in the inner tube. Accordingly, the magnetic field generating unit can increase the local magnetic field to further increase the thermal conductivity of the magnetic nanofluid.

In the present invention, the magnetic nanoparticle in the magnetic nanofluid is not particularly limited, and may be any magnetic nanoparticle such as ferric oxide nanoparticles, triiron tetroxide particles or a mixture thereof. And the particle size is preferably less than 10 nm; in addition, the liquid fluid in the magnetic nanofluid is also not particularly limited, and may be any liquid fluid suitable for use in a heat pipe, such as water, oil, acetone, decene. , ethylene glycol, liquid or mixed fluoride; Furthermore, the concentration of magnetic nanoparticles in the liquid fluid is preferably 1.6 × 10 ^-2 emu / g to 8 emu / g.

In the present invention, the filling amount of the magnetic nanofluid is preferably from 30 to 50% by volume based on the total volume of the heat dissipating device.

In the present invention, the capillary structure is not particularly limited, and may be any conventional capillary structure, and includes, for example, a wire mesh structure (such as a copper mesh), a groove structure, a sintered structure, a fiber structure, or an etched structure.

In the present invention, the two ends of the heat dissipating device may be an evaporation portion and a condensation portion, respectively. Here, the evaporating portion and the condensing portion may use a capillary structure having a different degree of density. Preferably, the evaporating portion uses a denser capillary structure (that is, the capillary structure density at the evaporation portion is higher than the capillary structure density at the condensing portion). ) to increase the amount of working fluid evaporation.

In the present invention, the magnetic nanofluid can generate a gas-liquid phase coexisting transport unit in a transport flow path, and can effectively conduct waste heat from the evaporation portion to the condensation portion. Here, the transport channel can be located in the first cavity or the second cavity. In detail, the transport flow path may be located in the first cavity, and the capillary structure may be coated on the inner wall of the second cavity; or the transport flow channel may be in the second cavity, and the capillary structure is Covered on the inner wall of the first cavity.

In the present invention, when the transport flow channel is located in the first cavity, the first cavity or the second cavity may include a receiving portion located on the outer side of the transport flow path, so that the magnetic field generating unit can It is disposed in the accommodating portion. On the other hand, when the transport channel is located in the second cavity, the second cavity may include a receiving portion located on the outer side of the transport channel, so that the magnetic field generating unit can be disposed in the receiving In the ministry. Moreover, the magnetic field generating unit may be disposed on the outer side of the outer tube. Accordingly, the magnetic field generated by the magnetic field generating unit can transversely pass through the transport flow path. In addition, the magnetic field generating unit preferably generates a magnetic field of appropriate intensity, and the local magnetic field can be increased without affecting the flow of the magnetic nano-fluid, and the magnetic nano-particles are prevented from being adsorbed into the tube, thereby causing a decrease in heat transfer performance of the heat dissipating device. Preferably, the magnetic field generating unit has a magnetic field strength in the transport channel of from 1000 Oe to 4000 Oe, more preferably from 1000 Oe to 3000 Oe, most preferably 2000 Oe.

In the present invention, the magnetic field generating unit is not particularly limited, and may be any element that generates a magnetic field, such as a ring static magnet, a quadrupole static magnet, an electromagnet or the like.

The heat dissipating device of the present invention may further include: an induction coil disposed on a periphery of the outer tube to cause the induction coil to generate an induced current due to a change in a magnetic field caused by the flow of the magnetic fluid. Accordingly, the heat sink can also be electrically connected to a power device (such as a fan, USB, battery, etc.) to provide power to the power device.

According to the above, the present invention uses a double-tube heat pipe structure to flow the vaporized gas phase of the working fluid (ie, magnetic nanofluid) and the high-temperature liquid phase and the condensate in different flow paths to avoid the conventional single tube. The problem of dry burning of the evaporation part that is prone to heat pipe. Here, when the magnetic nano-filled fluid filled in the heat-dissipating device of the present invention is heated, the liquid fluid can be transferred by heat transfer by evaporation and condensation to achieve the effect of rapidly transferring heat; in addition, The collision between particles and particles in the rice fluid and the collision of the particles with the tube wall to effectively improve the heat transfer effect. In particular, in the heat dissipating device of the present invention, the end walls of the inner tube are formed with openings similar to those of the nozzle, so that the magnetic nano-fluid can form a gas-liquid phase coexisting transmission unit when heated, so as to avoid the conventional single-tube heat pipe. It is prone to the problem that the thermal retention of the particles is caused by the indwelling of the particles, and the thermal contact effect can be exhibited without increasing the contact area or adding baffles or fins. The contact area can be increased or the baffles or fins can be added. The problem that the working fluid flow rate is slowed down is to achieve the purpose of rapid heat dissipation. Furthermore, the heat dissipating device of the present invention can be further provided with a magnetic field generating unit to increase the local magnetic field and improve the thermal conductivity of the magnetic nanofluid. Compared with the conventional loop pulse type heat pipe, the heat dissipating device of the invention can exhibit excellent heat transfer characteristics, and has the advantages of simple structure, low manufacturing cost and small volume.

The embodiments of the present invention are described by way of specific examples, and those skilled in the art can readily appreciate the other advantages and advantages of the present invention. The present invention may be embodied or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention.

Example 1

Please refer to FIG. 2 , which is a schematic diagram of a heat sink according to a preferred embodiment of the present invention.

As shown in FIG. 2, the heat dissipating device of the present embodiment includes: an outer tube 41; an inner tube 42 disposed in the outer tube 41, wherein the inner space of the inner tube 42 constitutes a first cavity A, and The space between the inner tube 42 and the outer tube 41 constitutes a second cavity B, and the end walls of the inner tube 42 have a plurality of openings 421 so that the first cavity A and the second cavity B are mutually Connected; a capillary structure 43 (in the present embodiment, the capillary structure 43 is a copper mesh structure), is coated on the inner wall of the second cavity B (ie, the outer wall of the inner tube 42 and the outer tube 41) a magnetic nanofluid 44 filled in the first cavity A and the second cavity B, the filling amount of which may be about 30 to 50 volume percent, wherein the magnetic nanofluid 44 comprises a liquid fluid 441 And a plurality of magnetic nano particles 442 having a particle diameter of less than 10 nm and a concentration in the liquid fluid 441 of about 1.6×10 ^-2 emu/g to 8 emu/g; The magnetic field generating unit 45 is disposed in the inner tube 42. Here, the first cavity A includes a transport flow path A1 and a accommodating portion A2, and both ends of the heat dissipating device serve as an evaporation portion B1 and a condensing portion B2, respectively, wherein the transport flow channel A1 is a magnetic nano-fluid 44 and evaporates The gas transports the flow path, and the accommodating portion A2 is located on the outer side of the transport flow path A1 and is for accommodating the magnetic field generating unit 45.

Accordingly, referring to FIG. 2, when the magnetic nanofluid 44 of the capillary structure 43 on the inner wall of the outer tube 41 is vaporized by the heating of the outer tube 41, the high-pressure vapor passes through the opening 421 at the evaporation portion B1 at a high speed. The inner tube 42 is inserted, and at the same time, the magnetic nano-fluid 44 of the capillary structure 43 on the outer wall of the inner tube 42 is pushed. Therefore, a small gas is formed in the transport channel A1 of the first chamber A to push a small portion of the magnetic nano-fluid gas. The phase coexisting transmission unit, and the magnetic field generating unit 45 of the accommodating portion A2 can generate a magnetic field transversely passing through the transport channel A1 (ie, the magnetic field is perpendicular to the transmission direction of the gas-liquid phase transmission unit) to increase the local magnetic field and improve transmission. The heat transfer coefficient of the magnetic nanofluid 44 in the unit, wherein in order to increase the evaporation amount of the working fluid, the evaporation portion B1 preferably uses a densely dense capillary structure 43; and then, when the transfer unit flows to the condensation portion B2, the magnetic nanometer The fluid 44 first wets the capillary structure 43 on the outer wall of the inner tube 42 and then flows to the capillary structure 43 on the inner wall of the outer tube 41 by capillary force for heat exchange condensation, and the vapor passes through the condensation portion B2. The hole 421 and the capillary structure 43 enter the cold The condensation portion B2 is condensed; finally, the condensed magnetic nano-fluid 44 flows back to the evaporation portion B1, and scoured the magnetic nanoparticles 442 remaining on the inner wall 41 of the outer tube 41 during evaporation to cause the magnetic nano-particles The particles 442 flow into the magnetic nanofluid 44 of the capillary structure 43 on the outer wall of the inner tube 42.

As described above, the main structural features of the heat dissipating device provided in this embodiment are as follows: (1) Both ends of the inner tube have a plurality of openings (acting as nozzles), which are favorable for forming a transmission unit in which gas and liquid phases coexist, avoiding The problem that the magnetic nanoparticles are left in the evaporation portion and the thermal resistance is increased; (2) the evaporation gas phase and the high temperature liquid phase and the condensate flow in different flow paths.

Example 2

The heat sink of this embodiment is substantially the same as that described in Embodiment 1, except that the magnetic field generating unit 45 of the present embodiment is disposed between the inner tube 42 and the outer tube 41. In detail, referring to FIG. 3, in the embodiment, the second cavity B includes a receiving portion B3 between the inner tube 42 and the outer tube 41, and the magnetic field generating unit 45 is disposed on In the housing portion B3.

Example 3

The heat sink of this embodiment is substantially the same as that described in Embodiment 1, except that, as shown in FIG. 4, the magnetic field generating unit 45 of the present embodiment is disposed on the outer side of the outer tube 41.

Example 4

The heat dissipating device of the embodiment is substantially the same as that of the first embodiment, except that, as shown in FIG. 5, the heat dissipating device of the embodiment further includes an induction coil 46 disposed on the periphery of the outer tube 41. Here, the induction coil 46 can be electrically connected to a power device 51 (such as a fan, a USB, a battery, etc.) to provide power to the power device 51.

Example 5

The heat dissipating device of this embodiment is substantially the same as that described in Embodiment 3, except that the transport channel of the embodiment is located in the second cavity, and the capillary structure is coated on the inner wall of the first cavity. on.

Accordingly, when the magnetic nanofluid in the evaporation portion of the heat sink is heated and vaporized, the high pressure vapor pushes the magnetic nanofluid, and a small gas is formed in the second cavity to push a small amount of magnetic nanofluid gas. a liquid phase coexisting transmission unit (that is, the transport flow path of the embodiment is located in the second cavity), and the magnetic field generating unit disposed outside the outer tube can generate a magnetic field transversely passing through the transport flow path (ie, the The magnetic field is perpendicular to the transmission direction of the gas-liquid phase transport unit) to increase the local magnetic field and increase the heat transfer coefficient of the magnetic nanofluid in the transmission unit. Among them, in order to increase the evaporation amount of the working fluid, the evaporation portion preferably uses a dense density capillary structure. Then, when the transfer unit flows to the condensing portion, the condensed liquid flows back to the evaporation portion along the capillary structure on the inner wall of the inner tube, and washes the magnetic nanoparticles remaining in the capillary structure on the evaporation portion during evaporation.

Test example 1

Filling 50% by volume of the total volume of the device into a conventional single-tube heat pipe (as shown in Figure 1A), and accounting for 50% by volume of the total volume of the magnetic nanofluid (concentration is about 8emu/g) The heat resistance is compared in a heat sink having a nozzle structure and an evaporating gas phase/high temperature liquid phase and a condensate flowing in different flow paths, and the heat resistance is compared under a heat transfer power of 20 W to 60 W, and the results are shown in FIG. 6 . Among them, R _MF refers to the thermal resistance of the heat sink filled with magnetic nozzles, and R _water refers to the thermal resistance of the single tube heat pipe filling water. In addition, the magnetic nanoflow system uses water and triiron tetroxide particles having a particle diameter of less than 10 nm as the liquid fluid and the magnetic nanoparticle, respectively.

As shown in FIG. 6, the heat resistance of the heat sink filled with the magnetic nanofluid is smaller than the heat resistance of the heat sink filling the water. It can be seen that the magnetic nanofluid is filled in the heat dissipating device having the nozzle structure of the present invention and the evaporating gas phase/high temperature liquid phase and the condensate flowing in different flow channels can indeed exhibit a better heat conduction effect.

Test example 2

Different concentrations of magnetic nanofluids (concentrations of about 1.6×10 ^-2 emu/g and 4 emu/g) were respectively filled in a heat sink with a nozzle structure, and filled with water under different applied magnetic field strengths. The heat transfer coefficient in the single-tube heat pipe (shown in Fig. 1A) is compared, and the results are shown in Fig. 7. Among them, K _MF refers to the heat transfer coefficient of the magnetic nano-fluid filled with the heat sink of the nozzle structure, and K _water refers to the heat transfer coefficient of the single-tube heat pipe filling water. In addition, the magnetic nanoflow system uses water and triiron tetroxide particles having a particle diameter of less than 10 nm as the liquid fluid and the magnetic nanoparticle, respectively. As shown in Fig. 78, when the magnetic field strength is 1000 Oe to 3000 Oe, the heat transfer coefficient of the heat sink filled with the magnetic nanofluid is better than that of the water-filled heat sink, and the magnetic nanofluid concentration is 4 emu/g and the magnetic field strength is At 2000 Oe, the best thermal conductivity is exhibited, and its heat transfer coefficient is about 3.7 times that of water.

11. . . Closed pipe

13,43. . . Capillary structure

14,24,34. . . Working fluid

twenty one. . . Closed loop tube

31. . . Multi-circuit tube

41. . . Outer tube

42. . . Inner tube

421. . . Opening

44. . . Magnetic nanofluid

441. . . Liquid fluid

442. . . Magnetic nanoparticle

45. . . Magnetic field generating unit

46. . . Induction coil

51. . . Power device

A. . . First cavity

A1. . . Transport channel

A2, B3. . . Housing

B. . . Second cavity

B1. . . Evaporation department

B2. . . Condensation

Figure 1A is a schematic view of a conventional single tube heat pipe.

Figure 1B is a schematic view of a conventional loop heat pipe.

Figure 1C is a schematic diagram of a conventional loop pulse type heat pipe.

2 is a schematic view of a heat sink according to a preferred embodiment of the present invention.

3 is a schematic view of a heat sink according to another preferred embodiment of the present invention.

4 is a schematic view of a heat sink according to another preferred embodiment of the present invention.

FIG. 5 is a schematic diagram of a heat sink according to another preferred embodiment of the present invention.

Fig. 6 is a comparison diagram of thermal resistance of a heat sink filled with a nozzle structure filled with a magnetic nanofluid and a single-tube heat pipe filled with water at different heat transfer powers.

Fig. 7 is a comparison diagram of heat transfer coefficients of different concentrations of magnetic nano-fluids and single-tube heat pipe filling water with different heat-dissipating devices having a nozzle structure under different magnetic field strengths.

41. . . Outer tube

42. . . Inner tube

421. . . Opening

43. . . Capillary structure

44. . . Magnetic nanofluid

441. . . Liquid fluid

442. . . Magnetic nanoparticle

45. . . Magnetic field generating unit

A. . . First cavity

A1. . . Transport channel

A2. . . Housing

B. . . Second cavity

B1. . . Evaporation department

B2. . . Condensation

Claims (17)

A heat dissipating device includes: an outer tube; an inner tube disposed in the outer tube, wherein an inner space of the inner tube constitutes a first cavity, and a space between the inner tube and the outer tube constitutes a a second cavity, and the two ends of the heat dissipating device are respectively an evaporation portion and a condensation portion, the end walls of the inner tube have a plurality of openings, so that the first cavity and the second cavity are mutually And a magnetic nanofluid filled in the first cavity and the second cavity, wherein the magnetic nanofluid comprises a liquid fluid and a plurality of magnetic nanoparticles. The heat dissipating device of claim 1, further comprising: a capillary structure covering the inner wall of the second cavity, and the magnetic nano flow system generates a gas phase in a transport channel A coexisting transmission unit, and the transport channel is in the first cavity. The heat dissipating device of claim 1, further comprising: a capillary structure covering the inner wall of the first cavity, and the magnetic nano flow system generates a gas phase in a transport flow path A coexisting transmission unit, and the transport channel is in the second cavity. The heat dissipating device according to claim 1, wherein the magnetic nanoparticles have a concentration in the liquid fluid of from 1.6×10 ^-2 emu/g to 8 emu/g. The heat dissipating device according to claim 1, wherein the magnetic nanoparticles have a particle diameter of less than 10 nm. The heat sink according to claim 1, wherein the liquid flow system is selected from the group consisting of water, oil, acetone, decene, ethylene glycol, fluorinated liquid, and mixtures thereof. The heat dissipating device according to claim 1, wherein the magnetic nanoparticles are iron oxide nanoparticles, triiron tetroxide particles or a mixture thereof. The heat sink of claim 1, wherein the magnetic nanofluid is filled in an amount of 30 to 50 volume percent of the total volume of the device. The heat sink of claim 2, wherein the capillary structure density at the evaporation portion is higher than the capillary structure density at the condensation portion. The heat dissipating device of claim 2, wherein the capillary structure is a mesh structure, a groove structure, a sintered structure, a fiber structure or an etched structure. The heat dissipation device of claim 2, further comprising: a magnetic field generating unit disposed in a periphery of the inner tube or in the inner tube, and the magnetic field generated by the magnetic field generating unit is transversely transmitted through the transmission Flow path. The heat dissipation device of claim 11, wherein the first cavity includes a receiving portion located on an outer side of the transport flow path, and the magnetic field generating unit is disposed in the receiving portion. The heat dissipating device of claim 3, further comprising: a magnetic field generating unit disposed on a periphery of the inner tube, and the magnetic field generated by the magnetic field generating unit is transversely passed through the transport flow path. The heat dissipation device of claim 11, wherein the second cavity comprises a receiving portion located on an outer side of the transport flow path, and the magnetic field generating unit is disposed in the space Set in the department. The heat sink according to claim 11 or 13, wherein the magnetic field generating unit is disposed on an outer side of the outer tube. The heat dissipating device of claim 11, wherein the magnetic field generating unit generates a magnetic field intensity of 1000 Oe to 4000 Oe at the transport flow path. The heat dissipation device of claim 11 or 13, further comprising: an induction coil disposed on a periphery of the outer tube.