KR20100108978A - Loop heatpipe using bubble jet - Google Patents

Abstract

PURPOSE: A loop type heat pipe using the bubble jet is provided to expand the range of operating temperatures and to enhance the heat transfer by the horizontal heating or the heating of the lower part. CONSTITUTION: A loop type heat pipe using the bubble jet comprises a bubble generating part and a U tube. The bubble generating part comprises an inner cylinder(320) and an outer cylinder(310). The caliber of the outer cylinder is larger than the caliber of the inner cylinder. A space into which a heating unit(330) can be inserted is formed on the inner side of the inner cylinder and a round-shape space(360) is formed on the gap between the outer cylinder and the inner cylinder. The nuclear boiling occurs in the round-shape space when the working fluid is heated. The U tube is connected to the bubble generating part and circulates the working fluid. If the heating unit radiates the heat, the bubble is generated by the nuclear boiling of the working fluid and the fluid irregularly circulates with vibration in the U tube due to the driving force of the bubble.

Description

Loop-type heat pipe using bubble jets

The present invention relates to a heat pipe, and more particularly, to a loop-type heat pipe that rapidly transfers heat by vibrating and circulating the working fluid using bubble propulsion force generated by nuclear boiling of the working fluid filled in the heat pipe.

In general, heat pipes are manufactured by injecting a working liquid such as methanol, anhydrous ethanol, purified water, a propanol-based liquid, or the like, which has a low boiling point and a high latent heat of evaporation, in a vacuum metal tube, and is produced at low pressure. A device that transfers heat to latent heat during phase change by using the feature that the working fluid easily changes from liquid to vapor, and its type is largely attached by attaching a porous wick to the inner surface of a sealed vacuum container. The wick's capillary phenomenon causes the working fluid to evaporate and condense, and the wick type heat pipe and the wick are inclined without attaching the wick so that the working fluid radiates from the condensation part (heat dissipation part). There is a thermo-syphon type heat pipe that collects in an evaporation section (absorption section) to repeat evaporation and condensation.

The heat pipe is used as an efficient heat transfer device for general air conditioning, heating and cooling, cooling of electronic devices, waste heat recovery in the middle temperature range, and solar heat collection. The advantage of the heat pipe widely used as a heat transfer device is that the heat transfer rate can be tens to hundreds of times higher than that of a copper wire such as copper, so the heat transfer rate is high and the heat transfer efficiency is excellent. .

A conventional heat pipe having this feature is shown in FIG. As shown in FIG. 1, the conventional heat pipe 100 operates by filling a working fluid into an inner space of the metal pipe 120, and blocks both ends of the metal pipe 120 with a metal stopper 130. The joint surface is welded and sealed, and the air is blown out through the inlet 140 of the metal plug 130 to maintain the inside of the metal pipe 120 of the heat pipe 100 in a state close to a vacuum, and then the inlet 140. After injecting the working fluid 110 through, it is produced by welding the injection port 140.

The heat pipe is largely divided into an evaporator 150, a heat absorbing part, a transfer part 160, a heat insulating part, and a condensation part 170, a heat radiating part. The heat pipe absorbs heat when heat is applied to the evaporator 150 where the heat source is located. The working liquid becomes a vapor state and diffuses inside the pipe body to pass heat from the condenser 170 through the transfer part 160. The working liquid which has released heat from the condensation unit 170 is condensed and then returned to the evaporation unit 150 by being in a liquid state. The working liquid transfers heat in the heat pipe by successively repeating condensation and evaporation. The evaporator 150 and the transfer unit 160 have a higher temperature than the condensation unit 170, and the vapor pressure in each part becomes saturated, and the vapor pressures of the evaporator 150 and the transfer unit 160 are increased in the condensation unit 170. Higher than vapor pressure. As a result of this, the vapor of the working liquid moves from the evaporator 150 to the condenser 170 through the transfer part 160.

In the case of the conventional heat pipe, the vapor generated during the evaporation of the working liquid is moved by the gravity difference in the space between the surface of the working liquid and the hot water pipe. When the heat pipe is horizontal, the surface of the working liquid and the hot water There is a problem in that heat transfer to the outside through the heat pipe is uneven because the gravity difference between the pipes is minute and steam generated when the working liquid is evaporated cannot be smoothly transferred to the other end (heat radiating part) of the heat pipe.

Thus, an improved heat pipe has emerged to solve the problem of the heat pipe installed horizontally as described above.

The improved conventional heat pipe is installed to be inclined by being supported by one end (heat radiating portion) of the heat pipe, or the heat radiating portion of the heat pipe is in contact with the hot water pipe by gravity by having the heat radiating portion above the heat absorbing portion in the vertical direction. As the working fluid is concentrated on the other end (heat absorbing part), the thermal contact area of the working fluid is expanded, which shortens the time for heating the whole working fluid, and also operates due to the gravity difference between the heat absorbing part and the heat radiating part of the heat pipe. When the liquid evaporates, the steam generated at the endothermic portion is transferred to the heat dissipating portion at a high speed, thereby smoothly transferring heat to the outside through the entire heat pipe.

In addition, according to the improved heat pipe, the working liquid which transfers heat to the entire heat pipe and condenses in the heat dissipation part can be easily returned to the heat absorbing part of the heat pipe.

However, although the improved heat pipe has the above advantages, there is still a limit in heat transfer rate and efficiency since basically the steam of the heated working liquid in the heat pipe is transferred through the heat pipe.

On the other hand, in addition to the thermosiphon type heat pipe described above, the wick type heat pipe, when the wicking heat pipe absorbs heat from the heat absorbing part and moves to the heat dissipating part, the heat dissipates. There is a problem in that the gaseous working liquid does not radiate directly to the space but heats through the wick, and thus its efficiency is low due to its heat resistance. Similarly, the heat pipe that was heated when the radiating working fluid condenses and returns to the endothermic part There is a problem that the temperature of the rather drop.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is intended to overcome the limitations in the heat transfer rate and efficiency of a technique using steam of a heated working liquid in heat transfer through a heat pipe.

In addition, since the fluid is circulated by the propulsion force of the bubbles due to the nuclear boiling of the fluid filled in the heat pipe, the heat pipe evenly transfers heat to the entire heat pipe, excluding differential heat transfer that only heats a specific portion of the heat pipe. To provide.

 In addition, in the conventional thermo-type heat pipe, the heat pipe has to be inclined to insulate the heat pipe in order to radiate heat from the heat radiating part and easily return the condensed hydraulic fluid to the heat absorbing part. However, this has eliminated the hassle in designing the heat pipe. To provide a heat pipe that efficiently achieves heat transfer and regression.

As a result, it is easy to manufacture and install the heat pipe, to eliminate the space constraints required for the heat pipe installation, and furthermore, to reduce the heat pipe manufacturing and installation costs.

In addition, the problem of the conventional wick type heat pipe, that is, the gaseous working fluid does not directly radiate heat into the space inside the wick, the heat resistance through the wick to solve the problem of low efficiency due to its heat resistance, the working fluid is directly radiated In order to provide a high efficiency heat pipe.

In addition, it is intended to provide a heat pipe having a high heat transfer rate and a high heat transfer efficiency by irregularly vibrating the working liquid filled in the heat pipe and functioning as a heat transfer medium.

In order to solve the above technical problem, the heat pipe according to an embodiment of the present invention is a loop type heat pipe in which operating fluid is injected, and includes an inner cylinder and an outer cylinder having a larger diameter and a longer length than the inner cylinder. It consists of a tube, but inside the inner cylinder is formed a space for the heating means can be inserted, an annular space is formed in the gap between the inner cylinder and the outer cylinder so that the nuclear fluid can occur when the working fluid is heat And a U tube connected to the bubble generating unit and circulating the working liquid, wherein when the heat generating means generates heat, bubbles are generated by nuclear boiling of the working liquid, The working fluid is characterized by irregularly vibrating circulation in the U tube.

The heat pipe according to another embodiment of the present invention similarly includes a bubble generating part that functions as a heat absorbing portion and a U tube that functions as a heat dissipating portion, and the bubble generating portion has a larger diameter and a longer length than the inner cylinder and the inner cylinder. By including the outer cylinder is made in the form of an annular double tube, the inner cylinder is formed with a space for the heating means can be inserted, the gap between the inner cylinder and the outer cylinder, the working fluid is nucleate boiling during heat The annular space is formed so that it can be formed, the U tube is connected to the bubble generating section and circulates the working fluid. It vibrates and circulates in the U tube, and is attached to the outer surface of the inner cylinder in the longitudinal direction, and bubbles generated by nuclear boiling of the working fluid At least one guide for guiding may further include.

A heat pipe according to still another embodiment of the present invention includes a bubble generating portion that functions as a heat absorbing portion and a U tube that functions as a heat dissipating portion, and the bubble generating portion has a larger diameter and a longer length than the inner cylinder and the inner cylinder. By including the cylinder is formed in the form of an annular double tube, the inner cylinder is formed inside the space for the heating means can be inserted, the gap between the inner cylinder and the outer cylinder, the nuclear fluid will be generated when the working fluid is heat The annular space is formed so that the U tube is connected to the bubble generating unit and circulates the working liquid. Vibrating and circulating in the U tube, the heating means may be a heat-transfer film or a heater that self-heats as the external power is supplied.

A heat pipe according to still another embodiment of the present invention includes a bubble generating portion that functions as a heat absorbing portion and a U tube that functions as a heat dissipating portion, and the bubble generating portion has a larger diameter and a longer length than the inner cylinder and the inner cylinder. By including the cylinder is formed in the form of an annular double tube, the inner cylinder is formed inside the space for the heating means can be inserted, the gap between the inner cylinder and the outer cylinder, the nuclear fluid will be generated when the working fluid is heat The annular space is formed so that the U tube is connected to the bubble generating unit and circulates the working liquid. It vibrates and circulates within the U tube, and may further include a reentrant cavity or fins on the outer surface of the inner cylinder.

A heat pipe according to still another embodiment of the present invention includes a bubble generating portion that functions as a heat absorbing portion and a U tube that functions as a heat dissipating portion, and the bubble generating portion has a larger diameter and a longer length than the inner cylinder and the inner cylinder. By including the cylinder is formed in the form of an annular double tube, the inner cylinder is formed inside the space for the heating means can be inserted, the gap between the inner cylinder and the outer cylinder, the nuclear fluid will be generated when the working fluid is heat The annular space is formed so that the U tube is connected to the bubble generating unit and circulates the working fluid. When the hydrothermal is generated, bubbles of the working fluid are generated by nuclear boiling, and the working fluid is generated by the propulsion force of the generated bubbles. A loop-type heat pipe that vibrates and circulates in a U tube, and attaches a mesh to an outer surface of an inner cylinder.

According to the present invention, the heat transport amount is greatly improved by horizontal heating or lower heating, and the operating temperature range can be expanded, and the structure is simple to provide a high productivity bubble jet vibration loop heat pipe. That is, the endothermic portion of the heat pipe is composed of an inner cylinder and an outer cylinder, and the heat transfer speed of the heat pipe is further increased by circulating the working liquid using the bubble propulsion force generated by the nuclear boiling of the working liquid in a narrow space between the cylinders. And heat transfer evenly through the heat pipe, while suppressing heat loss.

In addition, according to the present invention, the operating fluid absorbing heat in the heat absorbing portion, which is a disadvantage of the conventional thermosyphon type heat pipe, is liquefied after transferring heat to the condensing portion, so as to give an inclined surface to the heat pipe so as to return to the evaporation portion. It is effective to solve the troublesome work of precision construction.

In addition, since the present invention is structurally improved compared to the prior art, the external heat generating means can be applied only to the heat absorbing portion of the heat pipe, thereby reducing the cost and energy consumption of the heat generating means.

In addition, when the external heat generating means is inserted into the inner cylinder of the heat pipe and the external heat generating means is driven by the AC power source, it is possible to shield the formation of the magnetic field generated from the external heat generating means.

In addition, by changing the wall surface of the inner cylinder of the heat pipe heat absorbing portion to the reentrant cavity, the low fin, and / or the mesh, the heat absorbing portion may be improved in performance and the thermal response efficiency of the heat conductor may be improved.

Hereinafter, the present invention will be described with reference to the accompanying drawings. In the following description, detailed descriptions of well-known technologies or configurations are omitted when it is determined that they may unnecessarily obscure the subject matter of the present invention. something to do.

The terms to be described below are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators, and the definitions should be made based on the contents throughout the specification for describing the present invention.

1 is a cross-sectional view schematically showing a conventional heat pipe, FIG. 2 is a plan view of a heat pipe according to an embodiment of the present invention, and FIG. 3 is a longitudinal section of a heat pipe for heating according to an embodiment of the present invention. FIG. 4 is a view showing that bubbles are generated inside the heat pipe to vibrate the working fluid, FIG. 5 is a boiling curve of a liquid, and FIG. 6 is a view of a heat pipe according to another embodiment of the present invention. 7 and 8 are views of an embodiment in which a reentrant cavity or a low fin is formed on an outer surface of an inner cylinder of a heat pipe of the present invention.

As shown in FIG. 2, the present invention relates to a heat pipe 200, and is largely comprised of a bubble generating unit 220 and a U tube 210, and the bubble generating unit 220 functions as an endothermic portion, and absorbs heat. The working liquid absorbed in the portion flows and radiates to the U-shaped terminal 240 of the U tube 210. The other end of the U tube 210 is connected to the bubble generator 220.

Generally, the heat pipe 200 is comprised from copper, stainless steel, ceramics, tungsten, etc. as a material. A power supply 230 may be connected to the bubble generator 220 of the heat pipe 200, and as will be described in detail below, the power supply 230 may supply power to an external heating means inserted into an endothermic portion of the heat pipe. Can be.

The U tube 210 forms a circular tube bent in a U shape and has a space in which a working liquid which is a composition for heat transfer is filled. In addition, the shape of the heat pipe body is not limited to a circular tube, it may take the form of a hollow tube having an elliptical, polygonal and various irregularities.

On the other hand, the composition for heat transfer used as the working liquid of the heat pipe can generally be used, such as freon gas, surfactant, distilled water, glycerin, aqueous sodium hydroxide solution, aqueous solution of binadine. However, since each of the working fluids vary in operating temperature as shown in Table 1 below, the working fluids may be appropriately selected depending on the intended use of the heat pipe.

Table 1 below shows five operating temperature ranges from cryogenic temperatures close to absolute zero to ultra-high temperature ranges above 1000 ℃.

Working temperature (℃)

Main working fluid
-270 ~ -70 (Cryogenic)

Helium, argon, krypton, nitrogen, methane
-70 ~ 200 (low temperature)

Water, freon refrigerant, ammonia, acetone, methanol, ethanol, etc.

200 to 500 (medium temperature)

Naphthalene, sulfur, mercury
500 ~ 1000 (high temperature)

Cesium, potassium, sodium
1000 or more (ultra high temperature)

Lithium, lead, silver

On the other hand, when there is chemical reactivity between the heat pipe material and the working fluid, even when the working fluid is filled while maintaining a constant vacuum degree, the working fluid circulates inside to react with the heat pipe to generate an inert gas, and the inert gas is the working fluid. Since it hinders the circulation of and causes a decrease in performance and life, it is necessary to match the heat pipe material and the working fluid so that they are not chemically reactive with each other.

Referring back to FIG. 2, in the bubble generator 220 of the heat pipe, the working fluid filled in the heat pipe is heated by an external heat generating means inserted therein, and when the heating fluid is heated to a predetermined temperature, the working fluid is nucleated. Generate bubbles.

The generated bubbles pump the working fluid, and the working fluid vibrates and circulates by the bubble propulsion force and transfers heat to the entire heat pipe while moving to the heat pipe end 240 through the U tube 210.

This way of vibrating circulation of the working fluid by the bubble propulsion force is referred to herein as a "bubble jet" method.

Next, the present invention will be described in more detail with reference to FIG. 3. 3 is a longitudinal sectional view of a heating heat pipe according to an embodiment of the present invention. The bubble generating part of the heat pipe is composed of an annular double tube structure of the outer cylinder 310 and the inner cylinder 320, and the length of the inner cylinder is shorter than the length of the outer cylinder so that the inner cylinder can be inserted into the outer cylinder. More preferably, the diameter of the inner cylinder is smaller than the diameter of the outer cylinder.

Since a space into which the heat generating means can be inserted is formed inside the inner cylinder, an external heat generating means 330 may be inserted into the space.

On the other hand, an annular space is formed in the gap between the inner cylinder and the outer cylinder so that nuclear boiling of the working fluid can occur. When the working fluid is heated by the heating means, bubbles are generated by the nuclear boiling of the working fluid in the annular space. do.

보다 충분히 높은 온도로 유지되는 표면과 접하고 있을 때 고체와 액체 계면에서 일어난다. Boiling is the process of phase change from liquid to gas, such as evaporation. Evaporation occurs when the vapor pressure at the liquid vapor interface is less than the saturation pressure of the liquid at a given temperature, while boiling is the saturation temperature of the liquid.

It occurs at the solid and liquid interface when in contact with a surface maintained at a sufficiently high temperature.

That is, boiling is the rapid formation of vapor bubbles at the solid-liquid interface in contact with the surface when it tries to rise from the free surface of the liquid when the bubble reaches a certain size.

On the other hand, when there is a flow along the heat transfer surface, a velocity boundary layer is generated when the flow velocity of the fluid is largely changed near the heat transfer surface. In the case of the conventional heat pipe, the working liquid condensed in the heat generating portion forms a wall surface. While the velocity boundary layer is thick because it flows in and out, the heat pipe according to the present invention vibrates and circulates irregularly due to the bubble propulsion force, so that the velocity boundary layer is thinned or destroyed to improve heat transfer rate. Will be.

In addition, similarly to the velocity boundary layer, when the temperature of the heat transfer surface is high or low, the temperature also changes greatly in the vicinity of the heat transfer surface and a temperature boundary layer is formed. In the case of the heat pipe according to the present invention, the working liquid By vibrating and circulating irregularly, the temperature boundary layer becomes thinner or breaks, thereby improving the heat transfer rate.

4 shows a state in which bubbles are generated inside the heat pipe when the external heat generating means is activated to apply heat to the heat pipe of FIG.

The boiling section will be described in more detail with reference to FIG. 5.

Zone (a) is a natural convection boiling zone, zone (b) is a nuclear boiling zone, zone (c) is a transition boiling zone, and zone (d) is a membrane boiling zone.

The present invention utilizes the nuclear boiling of the working fluid, the first bubble is generated at point A of Figure 5 when the working fluid is heated, the nucleation site (nucleation site) increases while moving to the point C of the boiling curve as the temperature increases The bubble generation rate increases.

Zone (b) can be further divided into two zones: in zones A to B, independent bubbles are formed at various special places on the heating surface, but these bubbles are separated from the surface and soon disperse into the liquid, rising bubbles The empty space formed by this is filled with liquid near the heating surface and this process is repeated.

The heat transfer coefficient and heat flux increase in the nuclear boiling zone is due to the mixing of liquids entering the heating surface.

Next, in the zones B-C, the temperature of the heating wire is further increased, so that bubbles are generated at a huge rate at numerous nuclei, creating continuous column of bubbles inside the liquid, and these bubbles reach the free surface and break up and release their contents. . The very high heat flux in this zone is due to the combination of liquid inflow and evaporation.

Point C has the maximum (critical) heat flux at which point the heat flux is recorded as the maximum.

In the same principle as described above, when the external heat generating means is inserted into the inner cylinder 320 of the bubble generating unit, and heating of the working liquid is started by the inserted heating means, the working liquid starts to boil to generate bubbles, and the heating is performed. As it proceeds, the working fluid nucleates in a narrow annular space between the inner cylinder 320 and the outer cylinder 310.

Bubbles generated due to the nuclear boiling action of the working fluid moves from the annular space 360 of the inner cylinder and the outer cylinder to the propulsion unit 340 due to the pressure difference while pushing the working liquid, and the working liquid also flows with the bubbles.

Since bubbles generated by nuclear boiling are irregular and continuously generated in large quantities, the working fluid filled in the heat pipe is pumped due to the propulsion force of the bubbles, and the vibration is circulated irregularly in the U tube.

The oscillating and circulating working fluid transfers heat to the entire heat pipe while reaching the U-shaped end 370 of the heat pipe. That is, the heat pipe is continuously pumped by the bubble propulsion force as long as the fluid is driven only in one direction to transfer heat to the heat pipe, and after condensation and return to the endothermic part, but the heating means is driven. Heat is distributed evenly throughout.

On the other hand, the heating means that can be inserted into the inner cylinder of the heat pipe can use a conventional cartridge heater, which is connected to the power source 230 and driven as mentioned in FIG. Any heat generating source capable of applying heat, including a heat transfer film or a heater using electricity as a power source as an external heat generating means, may be employed, and in the case of employing these, only an external heat generating means in the heat generating portion of the heat pipe. Since it can be applied, there is an effect that can reduce the cost and energy consumption of the external heating means. In addition, the power source can be either direct current or alternating current, and in particular, when the external heating means is driven by the alternating current power source, there is an effect of blocking or attenuating electromagnetic waves generated by the alternating current power by an internal cylinder in the heat pipe surrounding the heating means.

Next, another embodiment of the present invention will be described with reference to FIG. 6. The configuration further includes one or more guides 520 in the inner cylinder 510 of the bubble generator. Here, one or more guides 520 may be connected to the outer wall of the inner cylinder 510 of the heat pipe bubble generator, and in this embodiment, the three guides form an angle of 120 ° to each other and the inner cylinder in the longitudinal direction of the inner cylinder. It is connected to the outer surface of the. Such a guide allows the bubbles generated in the annular space between the inner cylinder and the outer cylinder to be guided more efficiently to the propulsion unit 340 and the U tube 350. That is, the guide connected to the heat pipe inner cylinder helps the flow of bubbles and the working liquid in the longitudinal direction, and also prevents the flow of the annular clearance between the inner cylinder and the outer cylinder in the circumferential direction.

On the other hand, the guide connected to the inner cylinder of the heat pipe is not limited to a straight shape, of course, can be deformed into a spiral or any other shape. In addition, the length, thickness, number, and / or width of the guide connected to the inner cylinder of the heat pipe is not limited to a specific value, and the length, thickness, and number of the guides serving to guide the generated bubbles to the driving unit. Any of, and / or width would be possible.

In one embodiment, three guides are connected to the outer wall of the inner cylinder 510 of the heat pipe bubble generator in FIG. 6, and the length of the guide may be longer than the length of the inner cylinder. That is, one end of the guide may be formed to pass through the end of the inner cylinder of the heat pipe bubble generating section to the driving section. In addition, the thickness of the guide may be set to abut the inner cylinder and the outer cylinder of the heat pipe bubble generator. In this case, the guide not only functions to guide the generated bubbles to the propulsion unit, but also brings about an effect of making the combination of the inner cylinder and the outer cylinder harder.

In addition, a reentrant cavity, which is a high-performance bubble generating heat transfer surface, may be inserted into an outer surface of the inner cylinder of the bubble generating unit, or a bubble generation promoting heat transfer surface or a mesh such as a low pin may be inserted. It can be inserted, or any other high performance heat transfer surface.

In this regard, FIG. 7 shows a shape in which a reentrant cavity is formed on the outer surface of the inner cylinder of the bubble generating unit, and FIG. 8 shows a shape in which low fins are formed on the outer surface of the inner cylinder of the bubble generating unit.

For reference, an experimental result of experimenting with the thermal response of the heat pipe according to the embodiment of the present invention will be described. However, since this is only an experimental example of the present invention, the present invention is not limited to the following embodiment.

First, the apparatus for experimenting the heat responsiveness of the heat pipe according to the present invention is largely a test unit with a heat pipe according to the present invention, a heat source unit for supplying a heat source to the test unit, a control unit for adjusting the amount of power supplied; And a measuring unit for measuring data.

First, the test unit manufactured by the heat pipe according to the present invention may be composed of a loop type heat pipe shown in FIG. 3.

Before filling the inside of the heat pipe with the working fluid, the inside is vacuumed, whereby a rotary pump and / or a turbine pump can be used.

Next, the working fluid is filled into the heat pipe. At this time, the working liquid is filled into the heat pipe by using a refrigerant filling cylinder, and when the filling of the working liquid is completed, the opening part filled with the working liquid is closed (sealed). Preferably, the closing of the heat pipe may be accomplished by cool welding by pinch off. That is, when the opening portion of the heat pipe is picked up using a forceps by a pinch-off joining method, line contact occurs at the bent portion while being bent due to pressure, and thus sticks together. Unlike the general welding, the bonding is performed only by pressurization at room temperature, not heating. In the case of a soft material such as copper or aluminum, it can be reliably joined so that closing, ie, fluid communication, is blocked by cool welding by pinch-off. Of course, the closing in the present invention is not limited to the above-described manner, and is referred to as closing, encompassing a process of joining one end to block fluid communication.

Next, a cylindrical heater may be used as the heat source part constituting the experimental apparatus of the present experimental example, and the controller may use a slidax that controls to supply a constant voltage to the heat source part.

As shown in FIG. 9, the heat pipe according to the present invention by the performance analysis method as described above showed an improved effect than the conventional heat pipe in terms of thermal conductivity and thermal efficiency. That is, in the case of using the heat pipe according to the present invention, the temperature rises and stabilizes within a short time, and the entire heat pipe is warmed evenly with little difference in temperature between the upper end, the middle end, and the lower end of the heat pipe. This is the result of verifying the improved heat transfer effect to the whole.

These heat pipes can be used not only for heating the building, but also for roads to prevent winter snow ice, greenhouse systems such as botanical gardens, freezer doors, bed insulation systems (especially medical beds), chemical agitators, etc. Can be.

In addition, the heat pipe according to the present invention has a merit that it can be freely used in the horizontal and vertical modes without limitations in space even in a limited space, unlike the conventional commercialized heat pipes.

Embodiments shown for the purpose of the present invention described above are only one embodiment in which the present invention is embodied, and as shown in the drawings, it can be seen that various forms of combinations are possible to realize the gist of the present invention.

Therefore, the present invention is not limited to the above-described embodiments, and various changes can be made by any person having ordinary skill in the art without departing from the gist of the present invention as claimed in the following claims. It will be said that the technical spirit of this invention is to the extent possible.

1 is a cross-sectional view schematically showing a conventional heat pipe.

2 is a plan view of a heat pipe according to an embodiment of the present invention.

3 is a longitudinal sectional view of a heating heat pipe according to an embodiment of the present invention.

4 is a view showing that bubbles are generated in the heat pipe to vibrate the working fluid.

5 is a boiling curve of a liquid.

6 is a perspective view of an inner cylinder of a heat pipe according to another embodiment of the present invention.

7 is a diagram showing an embodiment in which a reentrant cavity is formed on an outer surface of an inner cylinder of a heat pipe of the present invention.

8 is a view showing an embodiment in which a reentrant cavity or a low fin is formed on an outer surface of an inner cylinder of a heat pipe of the present invention.

9 is a graph showing the results of experiments on the heat conduction performance using the heat pipe of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS

100: heat pipe 110: working fluid

120: metal tube 130: metal stopper

140: injection hole 150: evaporation unit

160: transfer unit 170: condensation unit

200: heat pipe 210: U tube

220: heat pipe heat absorbing portion 230: power

240: heat pipe U-shaped end 310: outer cylinder

320: inner cylinder 330: heat generating means

340: propulsion unit 350: heat pipe body

360: annular space 510: inner cylinder

520: Guide

Claims (5)

In a loop type heat pipe in which operating fluid is injected, The heat pipe, By including an inner cylinder and an outer cylinder having a larger diameter and a longer length than the inner cylinder, the inner cylinder is formed in an annular double tube shape, and a space through which the heating means can be inserted is formed inside the inner cylinder. In the gap between the outer cylinder and the bubble generating unit, the annular space is formed so that nuclear boiling can occur during heating of the working liquid, A U tube connected to the bubble generating unit and circulating the working fluid; When the heating means generates heat, bubbles are generated by nuclear boiling of the working fluid, and the working fluid vibrates and circulates irregularly in the U tube due to the propulsion force of the bubbles. The method of claim 1, A loop type heat pipe further comprising one or more guides attached to the outer surface of the inner cylinder in a longitudinal direction and directing bubbles generated by nuclear boiling of the working fluid to the U tube. The method according to claim 1 or 2, The heat generating means is a loop type heat pipe, characterized in that the heat generating film or a heater that self-heats as the external power is supplied. The method according to claim 1 or 2, And a reentrant cavity or fin on an outer surface of the inner cylinder. The method according to claim 1 or 2, Loop type heat pipe, characterized in that to form a mesh (mesh) on the outer surface of the inner cylinder.

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