KR101593892B1 - Heat pipe operable below ice freezing temperature and cooling system having the same - Google Patents

Abstract

Provided is a heat pipe operable below ice freezing temperature, which is smoothly operated blow ice freezing temperature by preventing the ice formation of water, and a cooling system having the same. The heat pipe includes a pipe part which accommodates a working fluid, is sealed, and has a space for transferring the phase-transformed working fluid, an evaporation part which forms one end part of the pipe part, and evaporates the working fluid which absorbs heat, and a condensation part which forms the other end part of the pipe part and condensates the working fluid which emits heat. The working fluid is a nonazeotropic mixture, and includes a first fluid which consists of water and a second fluid which has a higher boiling point than water and is not mixed with water, and has a greater specific gravity than water. The working fluid is maintained in a liquid state before heat is supplied, and is vaporized when heat is supplied to the evaporation part.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pipe capable of operating at a temperature lower than a freezing point and a cooling system including the heat pipe,

The present invention relates to a heat pipe including water as a working fluid and a cooling system including the heat pipe. More particularly, the present invention relates to a heat pipe capable of operating at a temperature lower than a freezing point, And a cooling system including the same.

Most of the elements installed in various electric, electronic devices, electric and electronic devices are large and small heating elements. Particularly, semiconductor components such as a central processing unit of a computer, a transistor, and a diode element including a light emitting diode are vulnerable to heat and easily generate heat, so that proper level of cooling is necessarily required.

A heat pipe is a heat transfer device that contacts a heating element to transport and dissipate thermal energy. The heat pipe cools the heating element through the phase change and circulation process of the working fluid embedded in the tube. It is simple in structure, easy to change the shape, and does not require any additional power. . Korean Patent Laid-Open No. 10-2001-0004462 discloses an example of such a heat pipe.

A heat pipe can use various different types of working fluid suitable for the temperature of a heat source. When a material having a good thermal property is used as a working fluid, the heat transfer ability is improved and more efficient cooling is possible. Water is a very effective working fluid because it has a large amount of absorbed heat due to phase change and has excellent physical properties such as surface tension, which is involved in fluid movement in the tube.

However, when water is used as a working fluid, there is a problem that the heat pipe is not operated by icing when it is left in a device or apparatus or a low-temperature state (for example, 0 ° C or less). That is, even if evaporation occurs primarily due to heat absorption from the heating element, there is a problem that the water re-freezes and can not circulate on the side of the condensing portion from which heat is discharged. In order to solve such a problem, a method of shielding a condensing portion with a non-condensing gas and artificially reducing an icing section has been used. However, there has been a problem that a heat transfer section is reduced and a cooling efficiency of a heat pipe is greatly reduced.

Korean Patent Publication No. 10-2001-0004462 (2001.01.15)

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a heat pipe capable of operating at a temperature below the freezing point, And a cooling system including the same.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method and apparatus for controlling the same.

A heat pipe operable at a temperature lower than the freezing point according to the present invention comprises: a tubular body portion in which a working fluid is received and closed, and a space is formed in which the working fluid is phase- An evaporator which forms one end of the tubular body and evaporates the working fluid by absorbing heat; And a condensing part which forms the other end of the tube part and in which the working fluid emits heat to be liquefied, wherein the working fluid is a non-conjugate mixed fluid, the first fluid comprising water, A second fluid that is not mixed with water and has a specific gravity larger than that of the water, maintains a liquid state before heat is introduced, and vaporizes when heat is introduced into the evaporation portion.

The second fluid may have a lower freezing point than the first fluid.

The amount of liquefaction energy of the second fluid may be equal to or greater than the amount of the dissolution energy of the first fluid.

Wherein the second fluid is selected from the group consisting of 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-trifluoromethyl- 3,3,4,4,4-nonafluoro-N, N-bis (nonafluorobutyl) butan-1-amine 1,1,2,2,3,3,4,4,4-nonafluoro-N- (nonafluorobutyl ) -N- (trifluoromethyl) butan-1-amine (1: 1).

The working fluid may maintain a contact area between the first fluid and the evaporator greater than a contact area between the second fluid and the evaporator before heat is introduced into the evaporator.

A cooling system according to the present invention comprises: an evaporating section block having at least one surface contacting a heat source; At least one first heat pipe being a heat pipe operable at a temperature below the freezing point at which the evaporation portion is inserted and fixed in the evaporation portion block; And at least one second heat pipe adjacent to the first heat pipe, wherein the evaporator is fixed to the evaporator block and uses only water as a working fluid.

In the cooling system, the heat transfer capacity of the second heat pipe may be greater than the heat transfer capacity of the first heat pipe.

In the cooling system, the first heat pipe and the second heat pipe may be alternately arranged.

The heat pipe capable of operating at a temperature below the freezing point according to the present invention can effectively cool a heating element by using water having excellent thermal properties as a working fluid and can freeze even in an environment where the apparatus or the apparatus is maintained at a temperature lower than a freezing point The heat pipe can be operated very smoothly.

Particularly, the heat pipe which can be operated at a temperature below the freezing point according to the present invention does not use a non-condensing gas to block the condensing portion, naturally freezes the ice with the thermal energy injected into the tube, circulates the working fluid, There is a very useful effect that high cooling efficiency can be maintained even at a low temperature below the freezing point.

In addition, the cooling system including such a heat pipe has an advantage that a plurality of heat pipes, which are different from each other even at a temperature below a freezing point, interact with each other and can operate smoothly. Further, There is an advantage that it can be improved.

1 is a partially cutaway perspective view of a heat pipe operable at a temperature below the freezing point in accordance with one embodiment of the present invention.
FIG. 2 and FIG. 3 are operation diagrams conceptually showing an operation process in which the heat pipe of FIG. 1 operates at room temperature.
Figs. 4 to 7 are operation diagrams conceptually showing an operation process in which the heat pipe of Fig. 1 operates at a temperature below the freezing point.
8 is a perspective view of a cooling system including a heat pipe operable at a temperature below the freezing point in accordance with one embodiment of the present invention.
Fig. 9 is a longitudinal sectional view showing the internal structure of the cooling system of Fig. 8; Fig.
Fig. 10 is a cross-sectional view showing the arrangement of the first heat pipe and the second heat pipe in the cooling system of Fig. 8;
FIG. 11 is a graph showing a comparison between a saturation pressure according to a temperature condition of water as a first fluid and a change in a saturation pressure according to a temperature condition of a specific material that can constitute the second fluid.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and methods for achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is only defined by the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a heat pipe operable at a temperature below the freezing point according to an embodiment of the present invention and a cooling system including the heat pipe will be described in detail with reference to FIGS. 1 to 10. FIG. First, referring to Figs. 1 to 7, description will be made of details of a heat pipe operable at a temperature below the freezing point, and the cooling system will now be described in detail with reference to Figs. 8 to 10 .

In the present specification, the term "freezing point" means a temperature at which a material is cooled and phase-changed from a liquid state to a solid state, and a "freezing point" means a temperature at which water becomes ice, in particular, water is frozen.

1 is a partially cutaway perspective view of a heat pipe operable at a temperature below the freezing point in accordance with one embodiment of the present invention.

1, a heat pipe 1 capable of operating at a temperature lower than a freezing point according to an embodiment of the present invention is constructed such that a working fluid 101 is accommodated therein and closed, and the working fluid 101 is phase- A vaporizing part 110 which forms one end of the tube part 100 and in which the working fluid 101 absorbs heat and evaporates; and an evaporator 110 which forms the other end of the tube part 100, And a condensing part (120) through which the liquid (101) emits heat to be liquefied. In this case, the working fluid 101 is a non azeotropic mixed fluid, which is composed of a first fluid 101a made of water and a second fluid 101a having a higher boiling point than water and being not mixed with water, (101b), maintains the liquid state before the heat is introduced, and evaporates and circulates when heat flows into the evaporator (110).

Particularly, even if the first fluid 101a made of water is frozen at a temperature below the freezing point, the second fluid 101b, which has a higher boiling point than water and is not mixed with water, is vaporized in the evaporated portion 110 The frozen first fluid 101a can be melted and circulated. That is, the heat pipe 1 which can be operated at a temperature below the freezing point according to an embodiment of the present invention is a non-ventilated type (one in which the respective fluids constituting the mixture evaporate at different temperatures, The mixed fluid of the first fluid 101a and the second fluid 101b having the characteristic of the mixed fluid having the individuality) can be used to smoothly operate not only at room temperature but also at a temperature lower than a freezing point.

In addition, the second fluid 101b has a specific gravity and is present in layers below the first fluid 101a, which is usually composed of water, but does not participate in the heat transfer process. The second fluid 101b selectively evaporates when the first fluid 101a is frozen and dissolves the first fluid 101a. When the first fluid 101a is thawed, the overall characteristics of the heat pipe 1 are the first Is governed by the fluid 101a. Accordingly, it is possible to provide a heat pipe 1 that can be smoothly operated even at a temperature lower than a freezing point, and which can efficiently cool water by using water having excellent thermal characteristics as a main heat transfer medium. Hereinafter, the structure and operation of the heat pipe 1 that can operate at a temperature below the freezing point will be described in more detail with reference to the respective drawings.

The tubular portion 100 is formed of a hollow tubular material. The working fluid 101 is accommodated in a hollow space inside the tubular body 100 and can move while being phase-transformed into a liquid or gas state. The inside of the tubular part 100 can be appropriately decompressed so that the working fluid 101 can move more smoothly and the tubular part 100 can be smoothly moved after the working fluid 101 is injected through one end of the tubular part 100 It can be completely sealed.

The tubular portion 100 may extend in the vertical direction as shown in the drawing, but the tubular portion 100 may be variously modified in correspondence with the shape of the installation site, the internal structure of the device in which the heat pipe 1 is installed, and the like. The tubular portion 100 may be at least partially inclined or may include a refracted portion. The tubular portion 100 may be freely deformed into various shapes as long as the working fluid 101 can easily move therein.

At least one radiating fin (200) is coupled to one side of the tubular part (100). A plurality of heat dissipation fins 200 may be coupled to the condensing portion 120 side of the tube portion 100 and a plurality of the heat dissipation fins 200 may be arranged in parallel to each other in a direction intersecting the extending direction of the tube portion 100. The heat dissipation fins 200 may be formed so as to increase the cooling efficiency by connecting mutually different heat pipes 1 to each other when a plurality of heat pipes 1 are formed. The tubular portion 100 and the radiating fin 200 may be made of a metal material having a high thermal conductivity, for example.

The evaporator 110 is formed at one end of the tubular body 100 and the condenser 120 is formed at the other end of the tubular body 100. The evaporator 110 and the condenser 120 are part of the tubular part 100 and are connected to each other through the inner space. The working fluid 101 circulates between the evaporator 110 and the condenser 120 through the space inside the tubular body 100 and transfers heat. The condenser 120 may be disposed at a position where the heat transferred through the working fluid 101 flows into the tubular portion 100. The condenser 120 may be disposed in the tubular portion 100, It can be the entire region that is emitted to the outside. The working fluid 101 is liquefied by absorbing and evaporating heat in the evaporator 110 and discharging heat in the condenser 120. [

The cooling efficiency can be increased by cross-coupling the radiating fins 200 to the condenser 120 as described above. Also, although not shown, a heat transfer material having a high thermal conductivity may be inserted between the evaporator 110 and the heat source, so that heat can be introduced from the heat source more quickly. The heat of the heating element flows into the evaporator 110, is transported along the working fluid 101 to the condenser 120, is discharged from the condenser 120, and dissipated. The working fluid 101 rapidly evaporates in the evaporator 110, absorbs the heat energy, condenses in the condenser 120, and rapidly transfers the heat of the heating body through the phase change process of discharging the heat energy.

The working fluid 101 includes a first fluid 101a and a second fluid 101b.

The first fluid 101a is water, and water has a large amount of endothermic or exothermic heat during the phase change process, and is excellent in physical properties related to fluid movement in the tube such as surface tension, and becomes a very effective heat transport medium. The second fluid 101b is a material having a boiling point higher than that of water, incompatible with water, and having a specific gravity larger than that of water. Thus, the water is phase-changed when it reaches a higher temperature condition without evaporating at the evaporating temperature. The second fluid 101b has a specific gravity greater than that of water and exists as a layer on the lower part of the first fluid 101a and is relatively heavy even if partly evaporated to remain in the lower part of the tubular body 100, .

The working fluid 101 is a non-azeotropic mixed fluid obtained by mixing the first fluid 101a and the second fluid 101b having different physical properties as described above. The working fluid 101 maintains the liquid state before the heat is introduced, ), Heat is absorbed and vaporized. The composition of the first fluid 101a and the second fluid 101b changes with the temperature condition of the working fluid 101, and the first fluid 101a made of water functions as a main heat transport medium. Particularly, when the first fluid 101a is frozen on the side of the condensing portion 120 at a temperature lower than the freezing point, the second fluid 101b evaporates on the side of the evaporator 110 which has been dried and the second fluid 101b And controls the first fluid 101a to melt and again participate in the heat transfer process. The second fluid 101b may be formed of a substance having a lower freezing point than the first fluid 101a made of water (i.e., a material having a freezing point lower than a freezing point), and may maintain a liquid state without freezing at a temperature below a freezing point.

That is, the second fluid 101b is preferably made of a material having a boiling point higher than that of water and not mixed with water, and having a specific gravity larger than that of water and a freezing point lower than a freezing point (in particular, a temperature at which water is frozen to ice) . Such materials include, for example, 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-trifluoromethyl-hexane, 2,3,3,4,4,4-nonafluoro-N, N-bis (nonafluorobutyl) butan-1-amine- 1,1,2,2,3,3,4,4,4-nonafluoro-N- (3M Novec 7500 Engineered Fluid (HFE7500), 3M Company (3M), and the like), and at least one of nonafluorobutyl-N- (trifluoromethyl) butan- Fluorinert Electronic Liquid FC-40 (FC-40), etc.) can be used. However, the present invention is not limited thereto, and various materials that satisfy the physical properties described above may be the second fluid 101b.

Referring to the graph of FIG. 11, the difference in physical properties between water and water and the material constituting the non-conjugate fluid can be more specifically described. 11 is a graph in which the saturation pressure (curve A) according to the temperature condition of water and the saturation pressure (curve B) according to the temperature condition of the above-described material HFE7500 are shown together.

In the vapor-liquid phase change, the temperature of the liquid rises, making it impossible to increase the internal energy due to the rise in temperature. That is, heat transfer takes place in a state where the internal energy is saturated, and the temperature and the pressure at this time are inherent characteristics of each material. As an example, water is at 100 ° C at standard atmospheric pressure (101325 pa) and the saturation temperature decreases with decreasing pressure.

As shown in the graph of FIG. 11, when the vapor pressure of water at the same temperature is higher than HFE 7500, for example, when the heat pipe is maintained at 60 占 폚, the internal pressure becomes 0.2 bar. Thus, in this saturated state, water vapor-liquid phase change from liquid to gas is achieved. However, the HFE 7500 is at an unsaturated (ie, compressible) state because the saturation temperature is higher than about 80 ° C at the same pressure. Therefore, HFE7500 does not cause vapor-liquid phase change because internal energy is unsaturated. When temperature increase occurs, it is only stored in liquid state due to internal energy of sensible heat.

On the other hand, when the temperature condition changes to reach the freezing point of water, the water freezes in a solid state and does not exist in a vapor state. The water is freezing in the condensing portion (see 120 in FIG. 2), and the evaporator (see 110 in FIG. 2) has the HFE 7500, which is much cooler than water, in a liquid state. At this time, when heat is applied to the evaporator, the temperature of the liquid HFE7500 rises and reaches the saturation state, and the pressure inside the heat pipe is controlled by HFE7500. Therefore, the saturated HFE7500 makes vapor-liquid change from liquid to gas and performs heat transfer to transfer the heat of the evaporator to the condenser. In addition, water and various materials such as HFE7500 decrease the relative saturation pressure difference at the same pressure when the temperature decreases. The pressure at the freezing point of water is 0.006 bar. HFE7500 has a vapor pressure lower than that of water at 0.001 bar at 7 ℃. The pressure is dominated and vapor-liquid phase changes occur.

Representative physical properties of exemplary materials that can produce a working fluid that is a non-conjugate fluid are tabulated below.

Properties

water
FC40
HFE7500
Freezing Point (℃)

0
-57
-100
1 atm Boiling point (℃)

100
155
128
Density (kg / m3)

1000
1850
1614

Hereinafter, the operation of the heat pipe 1 using the characteristics of the working fluid 101 will be described in more detail with reference to FIGS. 2 to 7. FIG.

Figs. 2 and 3 are conceptual diagrams illustrating an operation process in which the heat pipe of Fig. 1 operates at room temperature, and Figs. 4 to 7 are conceptual views of an operation process in which the heat pipe of Fig. 1 operates at a temperature below the freezing point Fig.

First, the operation process at room temperature will be described. In the present specification, 'ambient temperature' refers to a temperature higher than a freezing point where water freezes and does not become ice, and refers to a temperature at which the first fluid 101a is maintained in a liquid state.

When the evaporation unit 110 is brought into contact with the heat source at a normal temperature at which the first fluid 101a is not frozen, heat (refer to a refracted arrow at the lower end of the pipe unit) flowing into the evaporation unit 110 The temperature rises immediately. When the temperature of the first fluid 101a rises to the boiling point, evaporation occurs from the surface of the first fluid 101a in the liquid state and is vaporized. The vaporized first fluid 101a rises due to the molecular motion and reaches the condensing portion 120.

At this time, most of the heat introduced into the evaporator 110 is relatively absorbed by the first fluid 101a, which is phase-changed, at a relatively low boiling point. In addition, since the first fluid 101a continuously absorbs heat through a continuous phase change process, the second fluid 101b having a relatively high boiling point exists in a liquid phase layer below the first fluid 101a, It does not. In addition, even when a part of the second fluid 101b is partially vaporized, the second fluid 101b is relatively heavy and remains around the evaporator 110 as long as sufficient heat energy can not be provided, ).

Therefore, as shown in FIG. 3, the first fluid 101a made of water is circulated (see solid lines and dotted arrows inside the pipe section) between the evaporating section 110 and the condensing section 120, The heat transfer characteristic of the heat pipe 1 is governed by the first fluid 101a. The first fluid 101a rises to the gaseous state to reach the condenser 120 and emits the heat absorbed by the condenser 120 having a relatively low temperature and is liquefied. The emitted heat is rapidly dissipated along the radiating fin 200 coupled to the condenser 120 (see the refracted arrows around the radiating fin).

Although not shown, a capillary, a net, and a porous wick structure may be formed on the inner wall of the pipe 100 to guide the liquefied first fluid 101a to the condenser 120 quickly. The working fluid 101 has a contact area where the first fluid 101a and the evaporator 110 contact with each other in a liquid state before the heat is introduced into the evaporator 110, 110, the first fluid 101a can be more easily evaporated. The volume ratio of the first fluid 101a to the second fluid 101b in the liquid state before the heat is introduced may be greater than 1 (see FIG. 1).

Through this process, the heating body can be easily cooled at room temperature.

On the other hand, when the temperature is lower than the freezing point, the first fluid 101a can not circulate smoothly even when heat is introduced into the evaporator 110 as shown in FIG. That is, even if the evaporator 110 is frozen initially, heat is continuously supplied, so that there is no problem that the first fluid 101a is primarily vaporized inside the evaporator 110. However, when the vaporized first fluid 101a moves to the condenser 120 and then generates heat, the temperature falls below the freezing point, and is frozen as shown. Accordingly, as the ice sheet A is formed in the condenser 120, circulation of the first fluid 101a is stopped, and the amount of the first fluid 101a to be returned decreases, the evaporator 110 is dried.

When the evaporator 110 is dried, the heat injected into the evaporator 110 is absorbed by the second fluid 101b as shown in FIG. Accordingly, the second fluid 101b is overheated and reaches a relatively high boiling point, and the second fluid 101b in the evaporator 110 starts to evaporate. That is, the composition of the working fluid 101 changes at a temperature below the freezing point, and the second fluid 101b is phase-changed to temporarily participate in the heat transport process.

The vaporized second fluid 101b moves to the condenser 120 as shown in FIG. 6 and repeatedly and continuously contacts the ice sheet A. Thus, the second fluid 101b loses heat energy and liquefies, and the first fluid 101a acquires thermal energy and melts. Whereby the ice sheet A is removed and the freezing state of the first fluid 101a is eliminated. The first fluid 101a which has been melted and converted into the liquid state is returned to the evaporator 110 side together with the liquefied second fluid 101b.

Preferably, the liquefaction energy of the second fluid 101b (which may be the amount of liquefaction heat that the second fluid emits while changing phase from gas to liquid times the mass of the second fluid) (The amount by which the first fluid is multiplied by the mass of the first fluid multiplied by the heat of fusion absorbed by the phase change from the solid (ice) to the liquid). The second fluid 101b can be selected with appropriate consideration of such material properties.

Therefore, as shown in Fig. 7, the freezing is eliminated and the heat pipe 1 smoothly operates even at a temperature below the freezing point. The first fluid 101a returned to the evaporator 110 has a relatively low boiling point and is evaporated immediately after absorbing the heat of the evaporator 110. The second fluid 101b does not absorb sufficient heat, In the lower portion of the first fluid 101a. Therefore, in this case also, the medium that circulates and circulates between the evaporator 110 and the condenser 120 to actively transport heat is the first fluid 101a, and the heat transfer characteristic of the heat pipe 1 becomes the first fluid 101a ). If the temperature of the outside air is low and ice is formed again in the circulation, the evaporator 110 is dried and the second fluid 101b evaporates and the frozen state is instantly resolved.

That is, the heat pipe 1 capable of operating at a temperature lower than the freezing point according to the present invention utilizes the first fluid 101a made of water having excellent thermal characteristics as a main heat medium in both the normal temperature and low temperatures below the freezing point. Therefore, high cooling efficiency can be maintained. Also, the second fluid 101b dissolves the ice to start the heat pipe 1 and use the first fluid 101a to participate in the heat transfer process. Therefore, through the above-described process, the freezing is automatically eliminated more naturally and the cooling efficiency can be maintained by radiating heat through the entire condensing section 120 in which the ice is dissolved.

In this way, the heat pipe 1 can be smoothly operated at a low temperature below room temperature and freezing point to cool the heating element.

Hereinafter, a cooling system including a heat pipe operable at a temperature lower than a freezing point according to an embodiment of the present invention will be described in detail with reference to FIGS. 8 to 10. FIG.

FIG. 8 is a perspective view of a cooling system including a heat pipe operable at a temperature below the freezing point according to an embodiment of the present invention, FIG. 9 is a longitudinal sectional view showing the internal structure of the cooling system of FIG. 8, 8 is a cross-sectional view showing the arrangement of the first heat pipe and the second heat pipe of the cooling system in Fig. 8; Fig.

As shown in FIGS. 8 and 9, the cooling system 2 according to an embodiment of the present invention includes an evaporator block 30 having at least one surface contacting with a heat source, an evaporator 30 inserted and fixed in the evaporator block 30 (11) made of water and a second working fluid (11) composed of a second fluid (11b) having a higher boiling point than water and being not mixed with water and having a specific gravity larger than that of water, A first heat pipe 10 and a second heat pipe 20 adjacent to the first heat pipe 10 and having an evaporation part fixed to the evaporation part block 30 and containing a second working fluid 21 made of only water, . The first heat pipe 10 and the second heat pipe 20 may be identical in appearance but each have a different working fluid of the first working fluid 11 and the second working fluid 21, respectively.

At this time, the first heat pipe 10 is exactly the same as the heat pipe (see 1 in Fig. 1) operable at a temperature below the freezing point described above, and the first working fluid 11 is also the same as the above- (See 101 in Fig. 1) in which the fluid is mixed. The first heat pipe 10 and the first working fluid 2 are inevitably separated from each other in order to clarify the cooling system 2 differently from the second heat pipe 20, 11) are all replaced with descriptions of heat pipes operable at a temperature below the freezing point mentioned above, and the working fluid contained in the heat pipes.

The cooling system (2) according to an embodiment of the present invention includes a first heat pipe (10) capable of operating at a temperature lower than a freezing point by a first working fluid (11) which is a non- And a second heat pipe (20) using a second working fluid (21) composed of only the second working fluid (21). Therefore, the overall efficiency of the system can be controlled by water having excellent heat transfer characteristics, thereby exhibiting high cooling efficiency. The first heat pipe 10 and the second heat pipe 20 are arranged alternately adjacent to each other as shown in Fig. 10, so that the second heat pipe 20 is connected to the discharge heat of the first heat pipe 10, It is possible to eliminate the freezing of the ice. Therefore, the system can be smoothly driven even at a temperature lower than the freezing point.

The cooling system 2 includes an evaporation part block 30 and a condensation part block 40 made of a metal material having excellent heat conductivity. 8 and 9, the evaporator block 30 accommodates one end portion of the first heat pipe 10 and the second heat pipe 20 in a densely packed space in a relatively narrow space, The block 40 can reliably receive the other end portions of the first heat pipe 10 and the second heat pipe 20 in a state of being spaced apart from each other. One end of the first heat pipe 10 inserted into the evaporator block 30 and one end of the second heat pipe 20 function as an evaporator for absorbing the heat of the heating element, The other end of the first heat pipe 10 and the other end of the second heat pipe 20 function as a condenser for dissipating and dissipating the absorbed heat to the outside.

The first heat pipe 10 and the second heat pipe 20 are alternately arranged alternately with one another and the other as shown in FIG. Therefore, the heat released from the other end of the first heat pipe 10 reaches the second heat pipe 20, and the ice in the second heat pipe 20 can be relieved. The heat dissipation fin 200 can be connected between the other end of the first heat pipe 10 and the other end of the second heat pipe 20 to exchange heat more smoothly. The second heat pipe 20 including the second working fluid 21 made of only water can be smoothly operated at a temperature below the freezing point.

In particular, since the second heat pipe 20 uses only water as the working fluid, the heat transfer capacity of the first heat pipe 10 may be larger than that of the first heat pipe 10, which is mixed with the fluid, not the water. Therefore, it is possible to increase the arrangement of the second heat pipe 20 within an appropriate limit, thereby making it possible to increase the cooling efficiency of the cooling system 2.

When the cooling system 2 is used at room temperature, both the first heat pipe 10 and the second heat pipe 20 operate smoothly. Accordingly, heat can be transferred from the evaporator block 30 to the condenser block 40, and then released and dissipated easily. This allows efficient cooling.

On the other hand, when the cooling system 2 is used at a low temperature below the freezing point, the first heat pipe 10 first operates through the process as described above. Accordingly, the heat radiation action first proceeds from the other end side of the first heat pipe 10 coupled to the condenser block 40.

The heat energy is conducted along the heat dissipating fin 200 or directly to the second heat pipe 20 through the space between the first heat pipe 10 and the second heat pipe 20. Therefore, the ice formed on the condenser side of the second heat pipe 20 can be easily removed. The second heat pipe 20 can be operated more quickly by reducing the distance between the first heat pipe 10 and the second heat pipe 20, or by appropriately adjusting the arrangement state or the like in a state where heat transfer is easier . In this way, both the first heat pipe 10 and the second heat pipe 20 can be operated to effectively cool the heat generating element.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken in conjunction with the present invention. You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1: Heat pipe capable of operating at a temperature below freezing point
2: Cooling system
10: first heat pipe 11: first working fluid
11a, 101a: first fluid 11b, 101b: second fluid
20: second heat pipe 21: second working fluid
30: Evaporator block 40: Condenser block
100: tubular portion 101: working fluid
110: evaporator 120: condenser
200: heat sink fin
A:

Claims (8)

A tubular body portion in which a working fluid is received and sealed, and a space is formed in which the working fluid is phase-transformed to make a movable space;
An evaporator which forms one end of the tubular body and evaporates the working fluid by absorbing heat; And
And a condensing part forming the other end of the tubular part and being liquefied by releasing heat from the working fluid,
The working fluid is a non-
A first fluid comprising water and a second fluid having a boiling point higher than that of the water and not mixed with the water and having a specific gravity larger than that of the water and present as a layer under the first fluid, Wherein the evaporator is operable at a temperature below the freezing point of vaporization when heat is introduced into the evaporator. The method according to claim 1,
Wherein the second fluid is operable at a temperature below the freezing point, the freezing point being lower than the freezing point of the first fluid. The method according to claim 1,
Wherein the amount of liquefaction energy of the second fluid is operable at a temperature equal to or lower than the freezing point of the first fluid. The method according to claim 1,
Wherein the second fluid is 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-trifluoromethyl-hexane, and
1,1,2,2,3,3,4,4-nonafluoro-N, N-bis (nonafluorobutyl) butan-1-amine- 1,1,2,2,3,3,4,4, And at least one of 4-nonafluoro-N- (nonafluorobutyl) -N- (trifluoromethyl) butan-1-amine (1: 1). The method according to claim 1,
Wherein the working fluid is operable at a temperature equal to or lower than a freezing point at which a contact area of the first fluid and the evaporating portion is kept larger than a contact area of the second fluid and the evaporating portion in a state before heat is introduced into the evaporating portion. An evaporation part block at least one surface of which is in contact with a heat source;
At least one first heat pipe being a heat pipe according to any one of claims 1 to 5, wherein the evaporation portion is inserted and fixed in the evaporator portion block;
And at least one second heat pipe adjacent to the first heat pipe, wherein the evaporation portion is fixed to the evaporation portion block and uses only water as a working fluid therein. The method according to claim 6,
Wherein the heat transfer capacity of the second heat pipe is larger than the heat transfer capacity of the first heat pipe. The method according to claim 6,
Wherein the first heat pipe and the second heat pipe are alternately arranged.

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