JPH11257882A - Heat pipe and heat-collecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pipe where a refrigerant pipe at an evaporation part is arranged efficiently and that shows improved heat transportation efficiency on the large fluctuation of the amount of input heat, on start-up, and on steady state. SOLUTION: A heat pipe is a panel consisting of an evaporation part B where is heat is given externally and a condensation part B for emitting heat toward the outside, a refrigerant pipe 1 where a refrigerant is sealed inside is formed over the condensation part A and the evaporation part B, and the heat pipe is installed being inclined so that the evaporation part B is lower than the condensation part A. In this case, a branch pipe 1b being branched from a main pipe 1a of the refrigerant pipe 1 is formed at the evaporation part B and a residence part 1c of the refrigerant is provided at the tip of the branch pipe 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pipe for performing heat transport by evaporating and condensing a refrigerant, and relates to a ground heat pipe using gravity to return the condensed refrigerant and a heat collector using the heat pipe. .

[0002]

2. Description of the Related Art Typical heat pipes that have been put into practical use in the past are a wick heat pipe, a closed two-phase thermosiphon heat pipe, and a loop heat pipe. The wick type heat pipe is mainly for space use, and a porous wick material is attached to the inner wall of the refrigerant pipe, and the refrigerant condensed by the capillary force returns. Further, the closed two-layer thermosyphon heat pipe and the loop heat pipe are for use on the ground, and are installed at an angle to the ground so that gravity is used for reflux of the condensed refrigerant.

As a prior art of heat pipes, Japanese Patent Application Laid-Open No. 9-96451 discloses a heat collecting device for evaporating a refrigerant by heat or solar heat generated during photoelectric conversion of a solar cell. Further, Japanese Patent Application Laid-Open No. 8-210790 discloses a roll bond panel type heat pipe obtained by subjecting two bonded metal plates to an expansion process and having a wick function. The heat pipe is applied to various uses other than solar heat, such as cooling for removing heat from a heat generating portion of an electronic component, an electronic device, or the like.

[0004]

For example, when a heat pipe is used as a heat collector for solar heat and solar cells,
If the heat-generating portion of the electronic device provided with the heat pipe is vertically long, it is inevitable to reduce the size of the heat pipe and the heat collecting device.However, heat is applied from the outside to evaporate the refrigerant in the refrigerant pipe. In the evaporating section of the pipe, its size is restricted. Therefore, by arranging the refrigerant pipe pattern formed in the evaporating section without waste, the heat pipe can be miniaturized without shortening the refrigerant pipe length in the evaporating section.

[0005] The amount of heat received from sunlight, solar cells, and electronic devices may change rapidly or significantly due to changes in solar radiation, changes in electric power, and the like, and a stable amount of heat cannot always be obtained. In such a case, the operation of the refrigerant in the refrigerant pipe is not performed well, and the heat collection efficiency is reduced.

Here, the actual operation of the refrigerant is examined using a conventional heat collector provided with a heat pipe, and the problem is clarified. FIG. 19 is a schematic diagram of the solar heat collecting apparatus, and also shows the dimensions of each part. Heat pipe 10
Is a roll bond panel made of aluminum, and an appropriate amount of refrigerant HCFC-123 is sealed in an expansion pipe (refrigerant tube). The front surface is painted black, and the back surface is covered with a heat insulating material 11. Further, a rectangular heat collecting tank 12 is attached to the roll bond panel 10, and has a structure in which a fixed amount of water is circulated in the tank to absorb heat from the refrigerant.

FIG. 20 shows a refrigerant pipe pattern in the roll bond panel. The panel is divided into a condensing section (A), an evaporating section (B), and a heat insulating section (C), and a heat collecting tank 12 (see FIG. 19) is mounted on the condensing section (A).
A plurality of refrigerant pipes 1 parallel to each other are connected from the condensing section (A) to the evaporation section.
(B), and the refrigerant pipe 1 communicates with the lower end of the evaporating section (B) and the condensing section (A). Reference numeral 2 denotes a refrigerant charging port. After the inside of the refrigerant pipe 1 is evacuated, the refrigerant is injected from here and sealed.

[0008] In this roll bond panel, heat transfer of the refrigerant is performed as follows. That is, the refrigerant is evaporated
In (B), it receives heat and evaporates. This vapor flows from the evaporating section (B) whose pressure has increased to the low-pressure condensing section (A), where it is absorbed by the heat collecting tank 12 (see FIG. 19) to condense and liquefy. At this time, as shown in FIG. 19, since the roll bond panel 10 is installed so as to be inclined so that the condensing portion (near the formation of the heat collecting tank 12) is high, the refrigerant becomes a liquid film on the inner wall due to gravity. It flows down to the evaporation part (B). Then, it is again vaporized in the evaporating section (B).

The heat collecting apparatus having the above configuration is installed on the roof of the experimental building, and the evaporating section on the surface of the roll bond panel 10 under the condition of constant sunlight (about 860 W / m ² ) and constant outside air temperature (about 20 ° C.).
(B) Upper, middle, lower, and back of heat collecting tank 12 (condensing section
The time-dependent change of the temperature of (A)) is measured. FIG. 21 is a graph showing the change over time of the surface temperature. Initially, the road bond panel is shielded from sunlight and S
The shielding is removed at the time of TART.

In FIG. 21, the evaporating section (B) starts at the time of START.
It can be seen that only the temperature at the bottom continues to rise sharply, but at some point the temperature suddenly drops, and the temperature difference with the other parts disappears, resulting in a steady state. This is the evaporator (B)
When the refrigerant begins to absorb heat, the liquid refrigerant runs short (dry out) above the evaporator (B), and only the gaseous refrigerant evaporates.
(B) Circulates between the upper part and the condensing part (A), and the lower part of the evaporating part (B) raises the temperature of a large amount of refrigerant in a liquid state. It takes just over 5 minutes for the heat collector to reach steady state,
The amount of heat collected during this period is low. Therefore, the shortening of the rise time leads to an improvement in heat collection efficiency.

Next, in the above solar heat collecting apparatus, the evaporating section (B) of the roll bond panel 10 for each given amount of heat.
Measure the surface temperature. FIG. 22 shows a roll bond panel 1
0 indicates the temperature measurement position on the surface of the evaporating section (B), and the number on the left side in the figure indicates the distance from the lower end of the roll bond panel. The evaporator (B) was heated at a constant temperature (40 ° C., 50 ° C., 60 ° C., 70 ° C.) under the condition of an environmental temperature of 30 ° C., and the surface temperature in a steady state was measured. The heat collecting tank 12 (FIG. 1)
9) is 30 ° C.

FIG. 23 is a graph showing a surface temperature distribution for each heating temperature of the evaporating section (B). According to this figure, the center of the roll bond panel has a relatively uniform temperature distribution at any heating temperature. On the side of the roll bond panel, as the heating temperature increases, the temperature increases below the evaporating section (B).

As can be seen from the pattern of the refrigerant pipe 1 in the roll bond panel 10 (see FIG. 20), the refrigerant liquefied in the condensing part (A) flows down to the evaporating part (B) while heading toward the center of the load bond panel 10. Therefore, the refrigerant is insufficient at the lower portion on the side of the load bond panel 10 and the temperature rises. As a result, the heat transfer efficiency of the refrigerant decreases.

As described above, Japanese Patent Application Laid-Open No. 8-210
Japanese Patent Publication No. 790 discloses a heater pipe having a wick function in which the surface of the inner wall of a metal pipe is roughened. However, if the surface of the inner wall of the heat pipe is large, there is a problem that the metal plate is cracked by a bending action. Lack of reliability. In particular, relatively thin metal plates as heat pipe materials
When using (about 1 mm aluminum plate), metal damage due to cracking is remarkable.

Further, when the refrigerant pipe pattern of the heat pipe is complicated, the condensed refrigerant is less likely to flow down to the evaporator in the condenser, and the vaporized refrigerant is less likely to move from the evaporator to the condenser. There was a problem.

[0016] In a heat collector in which a solar cell is laid in the evaporating section of the heat pipe, the solar energy given to the heat pipe is not limited to the solar cell. Inevitably less than thermal equipment. There are few practical examples of the hybrid panel type heat collector, and such a problem has not been solved.

Here, the heat collecting performance and roll bonding of a roll-bond panel only type heat collecting device (see FIG. 19) and a hybrid panel type heat collecting device in which a solar cell is laid in the evaporating portion of the roll bond panel are shown. The temperature distribution on the panel surface is measured and compared.

FIG. 24 is a perspective view and FIG. 25 is an exploded perspective view of the hybrid panel type heat collecting apparatus. Insulation material 1
1, a roll bond panel 10 having a refrigerant tube (see FIG. 20), a solar cell 14 sandwiched between both sides by an epoxy resin 13, and a glass plate 15 are provided. A heat collecting tank 12 as a heat recovery means is installed on the upper surface of the condenser.

In any of the heat collecting devices, an equal amount of refrigerant is sealed in the refrigerant tube, and the volume of the refrigerant (liquid) at room temperature is about 50% of the volume of the refrigerant tube in the evaporating section. The temperature of the surface of the roll bond panel is measured at the upper, middle, and lower portions of the evaporator, and at the back of the heat collecting tank 12 (condenser).

FIG. 26 is a graph showing the surface temperature distribution of the roll bond panel 10 in each heat collecting device. According to this figure, the hybrid panel type has a lower surface temperature at each part than the roll bond panel only type. Also,
It is recognized that the temperature is higher in the lower part of the evaporating part, and the temperature difference from the condensing part is large.

When the refrigerant is operating normally in the refrigerant pipe, the temperature of each part tends to be uniform. However, in the hybrid panel type, the amount of heat given to the evaporator is reduced by the amount of solar energy used in the solar cell, so the temperature rises while the refrigerant remains liquid at the lower part of the evaporator,
Refrigerant is not working properly.

FIG. 27 is a heat collection efficiency diagram for each heat collection device. The horizontal axis is the heat collection efficiency variable, and the vertical axis is the heat collection efficiency, showing the heat collection efficiency for the hybrid panel type when the solar cell is not generated, for the hybrid panel type when the solar cell is generated, and for the roll bond panel only type. I have.

According to this figure, a roll-bond panel-only type has the best heat collecting performance, and a hybrid panel type that does not generate power has a heat collection efficiency lower by about 30% than the roll-bond panel-only type. Further, the heat collection efficiency of the hybrid panel type in which the power is generated is reduced by about 20% compared to the case without the power generation.

The cause of the decrease in heat collection efficiency of this hybrid panel type is the amount of heat received on the surface of the roll bond panel.
(Solar energy) may be blocked by solar cells or eva resin, but the drop of about 30% by itself is too large. Also, when solar cells generate electricity,
Although a decrease in the amount of heat collection corresponding to the power generation efficiency (several 10%) of the solar cell is expected, a decrease of about 20% is a further decrease in the heat collection efficiency.

There is a close relationship between the amount of heat input to the evaporator, the amount of refrigerant charged in the refrigerant pipe, and the amount of heat collection, and the optimum amount of refrigerant to be charged is determined in order to improve the heat collection efficiency of the heat collection device. There is a need to. However, detailed studies have not been conducted at present.

The present invention has been made in view of the above problems, and has a heat pipe in which refrigerant pipes in an evaporating section are disposed without waste. It is an object of the present invention to provide a heat pipe that exhibits the following characteristics, a heat pipe that is not easily damaged, and a heat pipe that allows the refrigerant to flow smoothly. Another object of the present invention is to provide a hybrid panel type heat collecting apparatus with improved heat collecting efficiency.

[0027]

According to another aspect of the present invention, a heat pipe is a panel including an evaporating section to which heat is applied from the outside and a condensing section to release heat to the outside. In a heat pipe in which a refrigerant pipe filled with a refrigerant is formed so as to straddle the condensing section and the evaporating section, and is installed so as to be inclined so that the evaporating section is lower than the condensing section, A branch pipe branching from the main pipe is formed, and a refrigerant retaining portion is provided at a tip of the branch pipe.

A heat pipe according to a second aspect of the present invention is characterized in that, in the heat pipe according to the first aspect, the staying portion is formed by closing a tip of a branch pipe.

A heat pipe according to a third aspect of the present invention is the heat pipe according to the first aspect, wherein a plurality of refrigerant pipes are provided, and the branch pipe communicates with a branch pipe of an adjacent main pipe to share a retaining portion. It is characterized by doing.

According to the configuration of the heat pipe, when the refrigerant condensed in the condensing section flows down to the evaporating section due to gravity, a part of the refrigerant flows into the branch pipe and stays in the accumulating section.
Then, evaporation and condensation are performed. Therefore, the refrigerant is always present even in the upper part of the evaporating section.

A heat pipe according to a fourth aspect of the present invention is the heat pipe according to any one of the first to third aspects, wherein the evaporating section is provided with a convex portion on at least one of the inner walls of the main pipe and the branch pipe. Features. According to this configuration, when the refrigerant condensed in the condensing section flows down to the evaporating section due to gravity, the refrigerant is retained by the convex portions provided in the main pipe and the branch pipe of the evaporating section. Therefore, the refrigerant is in a state where the refrigerant easily exists in the evaporating section.

A heat pipe according to a fifth aspect of the present invention is a panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, and a refrigerant pipe in which a refrigerant is sealed is provided between the condensing section and the evaporating section. In a heat pipe that is formed so as to be straddled and that is installed so as to be inclined so that the evaporating section is lower than the condensing section, the capacity of the refrigerant pipe on the side closer to the condensing section of the evaporating section is greater than on the side farther from the condensing section. Is increased.

According to a sixth aspect of the present invention, in the heat pipe of the first aspect, the branch pipe is formed more densely on the side closer to the condenser in the evaporator than on the side farther from the condenser. It is characterized by.

According to the configuration of the heat pipe, the volume of the refrigerant pipe is small at the lower part of the evaporating section, so that the liquid level of the condensed refrigerant accumulated therein is located higher. In addition, when the condensed refrigerant flows down the inner wall of the refrigerant pipe as a liquid film, it inevitably expands in the horizontal direction, but the surface area of the inner wall is large due to the large volume of the heat pipe in the upper part of the evaporator, and the refrigerant flows down accordingly. Speed slows down. Therefore, the refrigerant is likely to be present in the upper part of the evaporator.

According to a seventh aspect of the present invention, in the heat pipe according to any one of the first to fourth aspects, the sectional area of the main pipe is smaller on the side closer to the condenser in the evaporator than on the side farther from the condenser. It is characterized in that it is enlarged and the length of the branch pipe is shortened.

According to the heat pipe having the above-described structure, the length of the branch pipe is shorter toward the upper part of the evaporating section. Therefore, when a certain amount of refrigerant flows into the branch pipe, the remainder overflows and flows downward. Therefore,
The amount of the refrigerant flowing into and staying in each branch pipe is smaller at the upper portion of the evaporating section, and the refrigerant is uniformly staying in the entire evaporating section. Further, since the cross-sectional area of the flow path is larger in the upper part of the evaporator, the refrigerant is more likely to exist in the upper part of the evaporator in the same manner as in the fifth and sixth aspects of the invention.

The heat pipe according to claim 8 is a panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, and a refrigerant pipe in which a refrigerant is sealed has a condensing section and an evaporating section. In the heat pipe which is formed so as to extend over the condensing part and is installed so as to be inclined so that the evaporating part is lower than the condensing part, a sheet having an uneven surface is bonded to at least a part of the inner wall of the refrigerant pipe. It is characterized by the following. Also, the contact area between the refrigerant and the inner wall increases.

According to the heat pipe having the above structure, the inner wall is roughened by the sheet adhered in the refrigerant pipe.
The refrigerant flows down while spreading in the horizontal direction, and its speed decreases. Therefore, the refrigerant easily exists also in the upper part of the evaporating section, and the contact area between the refrigerant and the inner wall increases.

A heat pipe according to a ninth aspect is a panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, wherein a refrigerant pipe in which a refrigerant is sealed straddles the condensing section and the evaporating section. In the heat pipe, which is formed so as to be inclined so that the evaporating portion is lower than the condensing portion, the portion where the protrusion or the inner wall in the refrigerant pipe of the condensing portion adheres on the upper and lower surfaces is the It is characterized in that it becomes thinner in a direction parallel to the flowing direction.

According to the heat pipe having the above-described structure, when the portion where the protrusion or the inner wall is adhered on the upper and lower surfaces is narrowed in the flowing direction of the refrigerant, the condensed refrigerant flows down along the direction. When the refrigerant becomes thinner in the direction opposite to the downflow direction, the vaporized refrigerant flows in along the lower direction. Therefore, the movement of the refrigerant in the condensing section is easily performed.

A heat pipe according to a tenth aspect is a panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, and a refrigerant pipe in which a refrigerant is sealed is provided between the condensing section and the evaporating section. A heat pipe that is formed straddling and is installed so as to be inclined so that the evaporating part is lower than the condensing part, and a solar cell installed in the evaporating part of the heat pipe,
In a heat collecting apparatus provided with a heat recovery means provided in the condensing section of a heat pipe, the amount of the refrigerant sealed in the refrigerant pipe is a liquid at room temperature, which is about 20 times the volume of the refrigerant pipe in the evaporating section. -30%.

According to the heat pipe having the above-described structure, the heat is transported by the optimal amount of the charged refrigerant, so that the liquid pool of the refrigerant and the shortage of liquid (dry out) at the lower portion of the evaporating section can be suppressed as much as possible.

[0043]

Embodiments of the present invention will be described below with reference to the drawings. Members having the same configurations and names as those of the prior art are denoted by the same reference numerals, and description thereof will be omitted.

A first embodiment of the heat pipe according to the present invention will be described. FIG. 1 is a diagram showing a refrigerant pipe pattern in the heat pipe of the present embodiment. This heat pipe is manufactured by a method such as extrusion or welding using a metal pipe made of copper or aluminum, or a method of forming an expansion pipe between two metal plates (roll bond panel). It is.

In the evaporating section (B) of the heat pipe, a branch pipe 1b through which the condensed refrigerant flows from the main pipe 1a as the refrigerant pipe 1 is formed so as to extend obliquely downward. The distal end of the branch pipe 1b is closed, forming a stagnation section 1c in which the refrigerant stagnates. The position of the refrigerant charging port 2 is determined in consideration of evacuation, refrigerant charging, assembly, and the like.
The position is not limited to the position shown in FIG.

When the condensed refrigerant descends as a liquid film on the inner wall of the main pipe 1a, a part of the refrigerant flows into the branch pipe 1b and stays in the retaining section 1c, where the refrigerant evaporates and condenses. The specifications such as the formation pitch, length, and channel capacity of the branch pipe 1b are determined according to the ability as a heat collecting device. It is desirable that the formation position is particularly above the evaporating section (B) where the liquid is unlikely to remain, but the position and the arrangement of the branch pipe 1b are not limited to this embodiment.

For example, FIG. 2 shows another example in which the branch pipe 1b is formed as in the first embodiment. In the first embodiment, the branch pipes 1b extending on both sides from the main pipe 1a are formed alternately, but here, the branch pipes 1b are formed on both sides from the same position.
b is extended. As described above, any form may be used as long as the branch pipe 1b is formed with a layout with little waste.

FIG. 2 also shows an example of a practical size when actually used as a solar heat collecting apparatus.
Here, a panel area (983 mm × 807 mm) and a heat collecting tank having a heat transfer area of (690 mm × 100 mm) and a solar cell module (807 m
m × 783 mm). It is needless to say that the heat pipe of the present embodiment can be applied not only to a solar heat collecting device but also to a heat collecting device provided in a heat generating portion of an electronic device.

In the heat pipe of this embodiment, the condensed refrigerant flows into each branch pipe 1b and stays in the staying portion 1c.
Then, evaporation and condensation are performed. Therefore, since the refrigerant is always present in the upper portion of the evaporating section where the refrigerant is insufficient at the time of startup, when the input heat amount is small or fluctuates, the steady state of the refrigerant operation can be easily obtained, and good heat can be obtained. Transport efficiency is obtained. Further, since the layout of the refrigerant pipes in the evaporating section can be made to be a layout without waste, the length of the refrigerant pipe in the evaporating section can be sufficiently long even if the heat pipe is downsized.

Next, a second embodiment of the present invention will be described. FIG. 3 is a diagram showing a flow path pattern of the heat pipe of the present embodiment. Here, the branch pipe 1b formed in the main pipe 1a of the refrigerant pipe 1 is in communication with the branch pipe 1b of the adjacent refrigerant pipe 1, and a concave retaining portion 1c extending in the flowing direction of the refrigerant is formed there. .

FIGS. 4 to 6 show another example in which the structures of the branch pipe 1b and the staying portion 1c are different from those of the second embodiment. FIG.
In the heat pipe formation pattern shown in FIG.
It is shaped like a letter, and has a concave retaining portion 1c at the top. In the heat pipe formation patterns shown in FIGS. 5 and 6, the branch pipe 1b has a V-shape and a U-shape, and serves as a stagnant portion 1c where the refrigerant stagnates at the top.

In the second embodiment and the heat pipes shown in FIGS. 4 to 6, it is desirable to form a refrigerant pipe above the evaporating section where the refrigerant is less likely to remain. It is not limited to these. In addition, the retaining section 1
c may be formed at any position as long as the refrigerant can stay therein, and is not limited to one position in each branch pipe 1b, and may be provided at several positions.

In the heat pipe of this embodiment, the condensed refrigerant flows into each branch pipe 1b and stays in the staying portion 1c.
Then, evaporation and condensation are performed. Therefore, the refrigerant is always present even in the upper part of the evaporating section where the refrigerant is insufficient when the input heat amount is small or fluctuates at the time of startup, so that a steady state of the refrigerant operation can be easily obtained, and good heat can be obtained. Transport efficiency is obtained. Further, the refrigerant can flow down evenly in the left and right side directions of the evaporating section (B), and the heat collection efficiency is improved.

Next, a third embodiment of the present invention will be described. FIG. 7 is a diagram showing a part of the evaporator of the heat pipe of the present embodiment. In the refrigerant pipe 1, a branch pipe 1b is formed from the main pipe 1a as in the first embodiment, and the convex portion 3 is provided inside the main pipe 1a or the branch pipe 1b.

In the case of this heat pipe, for example, in the case of a roll bond panel formed by laminating two metal plates and partially expanding one or both of the metal plates, the inner wall of the refrigerant pipe of the metal plate is previously formed. It is good to provide a convex part in the part. It can also be formed by locally crushing a metal tube or the like.

The convex portion 3 may have any structure as long as the refrigerant can stay at the convex portion 3 when flowing down to the lower portion of the evaporating portion.
A corrugated shape, a jagged shape, a saw tooth shape, a gear tooth shape, or the like may be used. Further, the formation positions of the convex portions 3 may be random or may be only a part in the refrigerant pipe 1.

In the heat pipe of this embodiment, the condensed refrigerant stays in the convex portion 3 of the main pipe 1a or the branch pipe 1b, where it evaporates and condenses. Therefore, the refrigerant is always present even in the upper part of the evaporating section where the refrigerant is insufficient when the input heat amount is small or fluctuates at the time of startup, so that a steady state of the refrigerant operation can be easily obtained, and good heat can be obtained. Transport efficiency is obtained.

Next, a fourth embodiment of the present invention will be described. FIG. 8 is a diagram showing a formation pattern of the heat pipe of the present embodiment. In this heat pipe, in the heat pipe of FIG. 2, the formation density of the branch pipe 1b is made dense at the upper part of the evaporating section (B) and coarse at the lower part. As a result, the volume of the refrigerant pipe 1 increases on the side closer to the condenser (A),
It becomes smaller on the side farther to (A).

As means for making the volume of the heat pipe different between the upper part and the lower part of the evaporating section (B), besides the method of changing the formation density of the branch pipe 1b as shown in FIG.
The diameter of the main pipe 1a or the branch pipe 1b in FIG.
It may be larger on the side closer to (A) and smaller on the side farther from the condensing section (A).

In the heat pipe of this embodiment, the evaporator
(B) Since the volume of the heat pipe at the lower portion is small, the liquid level of the refrigerant can be located higher. In addition, in the upper part of the evaporating section (B), the surface area of the inner wall is large due to the large volume of the heat pipe, and the refrigerant that has turned into a liquid film inevitably spreads in the horizontal direction and flows down, so that the refrigerant flows down slowly. .

Therefore, since the refrigerant is always present in the upper part of the evaporating section where the refrigerant is insufficient when the input heat quantity is small or fluctuates at the time of startup, a steady state of the refrigerant operation can be easily obtained. Good heat transport efficiency is obtained.
Further, the heat exchange efficiency is also improved because the bonding area between the refrigerant and the inner wall is increased.

FIG. 9 shows another example having a partially different structure in relation to the fourth embodiment. In this heat pipe, in the heat pipe of FIG. 20 described above, the formation density of the communication pipe communicating with the adjacent refrigerant pipe main pipe 1a is made dense at the upper part of the evaporator (B) and coarse at the lower part.

Next, a fifth embodiment of the present invention will be described. FIG. 10 shows the evaporator (B) of the heat pipe of the present embodiment.
FIG. In this heat pipe, as in the first embodiment, a branch pipe 1 is connected to the evaporating section (B) from the main pipe 1a.
b is formed. In this refrigerant pipe 1, the diameter of the main pipe 1a is large on the side close to the condensing section and small on the side far from the condensing section. The branch pipe 1b is formed to have a shorter length on the side closer to the condensing portion and a longer length on the far side.

According to the configuration of the present embodiment, when the condensed refrigerant descends down the main pipe 1a and flows into the branch pipe 1b, since the length of the branch pipe 1b at the upper part of the evaporating section is short, a certain amount of refrigerant flows into the branch pipe 1b and the remaining refrigerant flows. Overflows and flows downward. Therefore, the branch pipe 1
The amount of the refrigerant flowing into and staying in b becomes smaller as it goes to the upper part of the evaporator.

In the heat pipe of this embodiment, there is no shortage of refrigerant at the lower part of the evaporator, and there is also refrigerant at the upper part of the evaporator. Therefore, in the related art, a steady state of the refrigerant operation can be easily obtained even at the time of starting or when the input heat amount is relatively small, and good heat transport efficiency can be obtained. Further, since the layout of the refrigerant pipes in the evaporating section can be made to be a layout without waste, the length of the refrigerant pipe in the evaporating section can be sufficiently long even if the heat pipe is downsized.

Next, a sixth embodiment of the present invention will be described. FIG. 11 shows a heat pipe of the roll bond panel of the present embodiment, and FIG.
It is sectional drawing in the a 'line. In this heat pipe, as in the first embodiment, a branch pipe 1b having a closed end is formed from the main pipe 1a of the expansion pipe (refrigerant pipe) 1, and the surface is formed on a part of the inner wall of the expansion pipe 1. The grooved sheet 5 is bonded. The roll bond panel includes, for example, two metal plates 4.
The grooved sheet 5 is bonded to one of the metal plates 4a, 4b, and then the metal plates 4a, 4b are attached to each other, and the tube is manufactured by a method of expanding the tube.

The grooved sheet 5 is a heat-resistant sheet that does not deform the metal during hot rolling, and may be any sheet that does not corrode the refrigerant. The groove size and the bonding position of the grooved sheet 5 may be determined in accordance with the size of the heat pipe and the heat collecting ability, and the grooved sheet 5 may be bonded to the entire surface of the expansion pipe 1. . Note that, here, a sheet having a groove formed on the sheet surface is used, but the present invention is not limited to this, and any sheet having an uneven shape may be used.

In the heat pipe of this embodiment, the expansion pipe 1
Since the inner wall surface is roughened by the grooved sheet 5 adhered to the inside, the coolant that has turned into a liquid film inevitably spreads in the lateral direction and flows down, so that the flowing speed of the coolant is slow. Therefore, the refrigerant is always present even in the upper part of the evaporating section where the refrigerant is insufficient when the input heat amount is small or fluctuates at the time of startup, so that a steady state of the refrigerant operation can be easily obtained, and good heat can be obtained. Transport efficiency is obtained. Further, the heat exchange efficiency is also improved because the bonding area between the refrigerant and the inner wall is increased. Further, the bonding of the grooved sheet 5 improves the strength of the refrigerant tube 1.

Next, a seventh embodiment of the present invention will be described. FIG. 13 is a diagram illustrating a condensing unit of the heat pipe of the present embodiment. In this condensing section, the main pipe 1 of the plurality of refrigerant pipes 1
a is integrated, and a protrusion 6 or a portion 6 having an inner wall adhered on upper and lower surfaces is formed inside. Conventionally, the projection or the portion where the inner wall is bonded on the upper and lower surfaces has been cylindrical (see FIG. 20).

In the present embodiment, the projection 6 (or the portion where the inner wall is adhered on the upper and lower surfaces) becomes thinner in a direction parallel to the flowing direction of the refrigerant, and becomes a rhombus as shown in the figure. I have. In addition, the part adhered on the upper and lower surfaces of the inner wall is, for example, an adhered surface formed by bonding two metal plates and subjecting them to bulging.

According to the heat pipe having the above-described structure, since the protrusion 6 (or the portion where the inner wall is adhered on the upper and lower surfaces) becomes narrower in the flowing direction of the refrigerant, the condensed refrigerant flows down along this direction. . Furthermore, since it becomes thinner in the direction opposite to the downflow direction, the vaporized refrigerant flows in along the lower direction. Therefore, the movement of the refrigerant in the condensing section is easily performed.

The protrusion 6 (or the portion where the inner wall is bonded on the upper and lower surfaces) may be tapered in a direction parallel to the flowing direction of the refrigerant so that the refrigerant moves smoothly. Either the flowing direction or the direction opposite to the flowing direction such as a mold or a bell shape may be thin, or both may be thin as in the present embodiment.

In the heat pipe of the present embodiment, the refrigerant is easily circulated to the evaporating section, so that the refrigerant remaining in the condensing section is minimized. In addition, the evaporated refrigerant is not blocked in the condensing portion, and flows into the condensing portion more easily. Therefore, the operation of the refrigerant is lubricated, and good heat transport efficiency is obtained.

The heat collecting apparatus according to the present invention is characterized in that the amount of the refrigerant sealed in the refrigerant pipe of the heat pipe is liquid at room temperature and is about 20 to 30% of the volume of the refrigerant pipe in the evaporating section. . The volume of the liquid at normal temperature is a value obtained by converting the weight of the refrigerant at an ambient temperature (about 30 ° C.) when the refrigerant is sealed in the refrigerant pipe into a liquid volume.

Here, the effect of the change in the amount of refrigerant charged and the amount of heat given to the evaporator on the heat collection performance will be examined, and the results of an experiment in which the optimum amount of charged refrigerant is determined will be described. The roll bond panel shown in FIG. 20 is used.
The total panel length is 983 mm x 807 mm, and the evaporator (B) length is 78.
3 mm, condensing part (A) 100 mm in length, and evaporating part (B)
Is 138 cc.

A heating panel in which a copper pipe is mounted on an aluminum plate is attached to the evaporating section (B) and the condensing section (A) of the roll bond panel, and constant-temperature water is circulated in the copper pipe. At this time, the temperature of the water supplied to the condenser-side heating panel and the outside air temperature were set at 30 ° C., and the temperatures of the water supplied to the evaporator-side heating panel were set at 40 ° C. and 60 ° C. Measure the temperature of the water discharged from the copper pipe.
The enclosed refrigerant is HCFC-123, and the amount of the enclosed refrigerant is 0 g, 25.72 g, 42.9 g, 56.56 g, 102.
46 g, 148.07 g (0 to about 70% of the volume of the evaporator).

The heat collection amount is calculated by the following equation. Q = Cpw · ρw · (Two−Twi) · V / 60 At this time, Q: heat collection amount (W) Cpw: specific heat of water (J / kg · K) ρw: density of water (kg / m ³ ) Two: Condensing part side drainage temperature (° C) Twi: Condensing part side feedwater temperature (° C) V: Water flow rate (L / min) on the condensing part side.

FIG. 14 is a graph showing the relationship between the amount of refrigerant charged and the amount of heat collected when the temperature of the water supplied to the evaporating section side panel is 40 ° C. According to this, the amount of charged refrigerant is 40 g.
The amount of heat collection is maximum when (volume of the evaporating section is 20%), and the amount of heat collection decreases as the amount increases. Also, it can be seen that the heat collection amount is small even if it is too small.

FIG. 15 is a graph showing the temperature distribution on the surface of the roll bond panel when the temperature of the water supplied to the evaporating section side panel is 40 ° C. The temperature at the center of the roll bond panel is shown above the graph. The measurement position is shown.
According to this, when the amount of the refrigerant is small, the surface temperature of the roll bond panel becomes uniform. In addition, when the amount of the refrigerant is large, a temperature rise is observed below the roll bond panel. In particular, 10
In the case of 2 g to 148 g, the temperature at the lower part of the roll bond panel is equal to 0 g of refrigerant (heating temperature), and it can be seen that heat transfer is not performed.

FIG. 16 is a graph showing the relationship between the amount of the charged refrigerant and the amount of heat collection when the temperature of the water supplied to the evaporating section side panel is 60 ° C. According to this, even when the heating temperature increases, the tendency does not change when the heating temperature is 40 ° C.,
The effect of the amount of the charged refrigerant on the amount of heat collected is not remarkably observed.

FIG. 17 is a graph showing the temperature distribution on the surface of the roll bond panel when the temperature of the water supplied to the evaporating section side panel is 60 ° C. When the heating temperature is high, the temperature of the lower part of the roll bond panel rapidly rises when the amount of the refrigerant is small (25.72 g), and the surface temperature of the roll bond panel is almost uniform when the amount of the refrigerant is large. .

From the above results, it is recognized that it is not appropriate that the amount of the charged refrigerant is too large or too small, and that the heat collecting performance is maximized at the optimum amount of the charged refrigerant. Here, the amount of heat collection was maximum when the amount of the enclosed refrigerant was about 40 g (a liquid amount of 20% of the volume of the evaporating section). When the amount of the filled refrigerant is more than about 40 g, when the heating temperature is low (40 ° C.), the temperature of the lower part of the roll bond panel is high, and the roll bond panel temperature becomes a uniform temperature distribution with the rise of the heating temperature. Therefore, it is considered that the liquid refrigerant stays below the roll bond panel.

When the amount of the filled refrigerant is less than about 40 g, when the heating temperature is low (40 ° C.), the temperature of the roll bond panel has a uniform temperature distribution. Temperature is high,
It is considered that the refrigerant was dry out at the lower part of the roll bond panel due to insufficient refrigerant. Therefore, about 40 g (about 20% of the volume of the evaporating section) with less liquid pool and dry-out at the lower part of the roll bond panel is optimal, and the maximum heat collection amount is obtained at this time.

Next, the amount of refrigerant enclosed in the heat pipe is about 60
g (about 30% of the volume of the evaporating section) was used to evaluate the heat collecting performance by a field experiment. here,
The heat collecting device shown in FIG. 24 is used. FIG. 18 is a heat collection efficiency diagram of the heat collection device. According to this figure, it is recognized that the heat collection efficiency is improved by more than 15% as compared with the conventional type indicated by the broken line (the amount of the enclosed refrigerant is about 50% of the volume of the evaporating section).
In addition, the kind of the refrigerant enclosed here is not limited,
Organic solvents such as methanol and acetone, and any refrigerants conventionally used such as Freon may be used.

In the heat collecting apparatus of the present invention, the refrigerant is sealed in an optimum amount, so that the liquid pool or the liquid shortage at the lower part of the evaporating section is obtained.
(Dryout) is suppressed as much as possible, the operation of the refrigerant is lubricated, and good heat transport efficiency is obtained, so that the heat collection efficiency is also improved.

[0086]

As described above, in the heat pipe according to any one of the first to third aspects, the condensed refrigerant flows into each branch pipe and stays in the staying portion, where evaporation and condensation are performed. Therefore, the refrigerant is always present even in the upper part of the evaporating section where the refrigerant is insufficient when the input heat amount is small or fluctuates at the time of startup, so that a steady state of the refrigerant operation can be easily obtained, and good heat can be obtained. Transport efficiency is obtained. Further, since the layout of the refrigerant pipes in the evaporating section can be made to be a layout without waste, the length of the refrigerant pipe in the evaporating section can be sufficiently long even if the heat pipe is downsized.

In the heat pipe of the fourth aspect, the condensed refrigerant stays at the convex portion of the main pipe or the branch pipe, and evaporates and condenses there. Therefore, the refrigerant is always present even in the upper part of the evaporating section where the refrigerant is insufficient when the input heat amount is small or fluctuates at the time of startup, so that a steady state of the refrigerant operation can be easily obtained, and good heat can be obtained. Transport efficiency is obtained.

In the heat pipes of claims 5 to 7, since the volume of the heat pipe in the lower part of the evaporator is small, the liquid level of the refrigerant can be located higher. In addition, since the volume of the heat pipe is large in the upper part of the evaporating section, the surface area of the inner wall is large, and the refrigerant that has become a liquid film naturally flows down while spreading in the horizontal direction, so that the refrigerant flows down slowly.

Therefore, the refrigerant is always present in the upper part of the evaporating section where the refrigerant is insufficient, such as when the input heat quantity is small or fluctuates at the time of startup, so that a steady state of the refrigerant operation can be easily obtained. Good heat transport efficiency is obtained.
Further, since the contact area between the refrigerant and the inner wall is increased, the heat exchange efficiency is also improved.

In the heat pipe of the present invention, since the inner wall surface is roughened by the uneven sheet adhered to the heat pipe, the refrigerant that has become a liquid film naturally spreads in the horizontal direction and flows down. The flow speed is slow.
Therefore, the refrigerant is always present even in the upper part of the evaporating section where the refrigerant is insufficient when the input heat amount is small or fluctuates at the time of startup, so that a steady state of the refrigerant operation can be easily obtained, and good heat can be obtained. Transport efficiency is obtained. Further, since the contact area between the refrigerant and the inner wall is increased, the heat exchange efficiency is also improved. Further, the strength of the refrigerant tube is improved by bonding the sheets.

In the heat pipe according to the ninth aspect, the refrigerant is easily circulated to the evaporating section to minimize the refrigerant remaining in the condensing section. In addition, the evaporated refrigerant is not blocked in the condensing portion, and flows into the condensing portion more easily. Therefore, the operation of the refrigerant is lubricated, and good heat transport efficiency is obtained.

In the heat collecting apparatus according to the tenth aspect, since the refrigerant is sealed in an optimal amount, liquid accumulation or liquid shortage (dryout) at the lower part of the evaporator is suppressed as much as possible, and the operation of the refrigerant becomes lubricated. Since good heat transport efficiency is obtained, heat collection efficiency is also improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a refrigerant pipe pattern of a heat pipe according to a first embodiment.

FIG. 2 is a plan view showing a refrigerant pipe pattern of a heat pipe according to another example of the first embodiment.

FIG. 3 is a plan view showing a refrigerant pipe pattern of a heat pipe according to a second embodiment.

FIG. 4 is a plan view showing a refrigerant pipe pattern of a heat pipe according to another example of the second embodiment.

FIG. 5 is a plan view showing a refrigerant pipe pattern of a heat pipe according to still another example of the second embodiment.

FIG. 6 is a plan view showing a refrigerant pipe pattern of a heat pipe according to still another example of the second embodiment.

FIG. 7 is a plan view showing a partial refrigerant pipe pattern of a heat pipe according to a third embodiment.

FIG. 8 is a plan view showing a refrigerant pipe pattern of a heat pipe according to a fourth embodiment.

FIG. 9 is a plan view showing a refrigerant pipe pattern of a heat pipe of an example related to the fourth embodiment.

FIG. 10 is a plan view showing a partial refrigerant pipe pattern of a heat pipe according to a fifth embodiment.

FIG. 11 is a plan view showing a partial refrigerant pipe pattern of a heat pipe according to a sixth embodiment.

FIG. 12 is a sectional view taken along the line aa ′ in FIG. 11;

FIG. 13 is a plan view showing a partial refrigerant pipe pattern of a heat pipe according to a seventh embodiment.

FIG. 14 is a graph showing a change in the amount of heat collection with respect to the amount of refrigerant charged in the heat collector when the evaporator heating temperature is 40 ° C.

FIG. 15 is a graph showing the temperature distribution on the panel surface when the evaporator heating temperature is 40 ° C.

FIG. 16 is a graph showing a change in the amount of heat collected with respect to the amount of refrigerant charged in the heat collector when the heating temperature of the evaporating section is 60 ° C.

FIG. 17 is a graph showing the temperature distribution on the panel surface when the evaporating section heating temperature is 60 ° C.

FIG. 18 is a heat collection efficiency diagram when the amount of refrigerant enclosed in the heat collection device is 30%.

FIG. 19 is a perspective view of a conventional heat collecting device.

FIG. 20 is a graph showing a temperature distribution on a panel surface of a conventional heat collecting device.

FIG. 21 is a plan view showing a refrigerant pipe pattern of a conventional heat pipe.

FIG. 22 is a plan view showing a surface temperature measurement position in an evaporating section of the heat pipe.

FIG. 23 is a graph showing a temperature distribution on a panel surface for each heating temperature in a conventional heat collector.

FIG. 24 is a perspective view of a conventional solar heat collecting apparatus.

FIG. 25 is an exploded perspective view of a conventional solar heat collecting apparatus.

FIG. 26 is a graph showing the temperature distribution on the panel surface of a conventional roll-bonded panel only type heat collector and a hybrid panel type heat collector.

FIG. 27 is a heat collection efficiency diagram of a conventional roll bond panel only type heat collector and a hybrid panel type heat collector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerant pipe 1a Main pipe 1b Branch pipe 1c Staying part 2 Refrigerant injection port 3 Convex part 4a Metal plate 4b Metal plate 5 Grooved sheet 6 Projection (or adhesion part on the upper and lower surfaces of inner wall) 10 Heat pipe 11 Heat insulating material 12 Heat collecting tank 13 Eva resin 14 Solar cell 15 Glass plate

Claims (10)

[Claims] 1. A panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, wherein a refrigerant pipe in which a refrigerant is sealed is formed over the condensing section and the evaporating section. A heat pipe that is installed so as to be inclined so that the evaporating section is lower than the condensing section. In the evaporating section, a branch pipe that branches off from the main pipe of the refrigerant pipe is formed. A heat pipe, wherein a stagnation portion for a refrigerant is provided at a tip of the tube. 2. The heat pipe according to claim 1, wherein the staying portion is formed by closing a tip of the branch pipe. 3. The heat pipe according to claim 1, wherein a plurality of the refrigerant pipes are provided, and the branch pipe communicates with a branch pipe of an adjacent main pipe to share the staying portion. 4. The heat pipe according to claim 1, wherein a protrusion is provided on an inner wall of at least one of the main pipe and the branch pipe in the evaporating section. 5. A panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, wherein a refrigerant pipe in which a refrigerant is sealed is formed across the condensing section and the evaporating section. In the heat pipe, which is installed so as to be inclined so that the evaporating section is lower than the condensing section, a side of the refrigerant pipe closer to the condensing section of the evaporating section than a side of the refrigerant section farther from the condensing section. Heat pipe characterized by increased volume. 6. The heat pipe according to claim 1, wherein the branch pipe is formed denser on a side of the main pipe closer to the condenser in the evaporator than on a side farther from the condenser. 7. The cross section of the main pipe is larger on the side of the evaporating section near the condensing section than on the side far from the condensing section,
The heat pipe according to any one of claims 1 to 4, wherein the length of the branch pipe is reduced. 8. A panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, wherein a refrigerant pipe in which a refrigerant is sealed is formed over the condensing section and the evaporating section. In the heat pipe, which is installed so as to be inclined so that the evaporating section is lower than the condensing section, a sheet having an uneven surface is bonded to at least a part of the inner wall of the refrigerant pipe. Heat pipe. 9. A panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, wherein a refrigerant pipe in which a refrigerant is sealed is formed across the condensing section and the evaporating section. In the heat pipe which is installed so as to be inclined so that the evaporating section is lower than the condensing section, the portion of the condensing section where the protrusion or the inner wall in the refrigerant pipe is adhered on the upper and lower surfaces is the A heat pipe characterized in that it becomes thinner in a direction parallel to a flowing direction. 10. A panel comprising an evaporating section to which heat is applied from the outside and a condensing section for releasing heat to the outside, wherein a refrigerant pipe in which a refrigerant is sealed is formed across the condensing section and the evaporating section. A heat pipe installed inclining so that the evaporating section is lower than the condensing section, a solar cell installed in the evaporating section of the heat pipe, and a condensing section of the heat pipe. In the heat collector provided with the installed heat recovery means, the amount of the refrigerant sealed in the refrigerant pipe is a liquid at room temperature and is about 20 to 30% of the volume of the refrigerant pipe in the evaporator. A heat collecting device.