heat pipe

Abstract

To provide a heat pipe configured by connecting a plurality of pipes.SOLUTION: A heat pipe 1 includes: a main pipe 2; and two or more sub-pipes 3 connected to an upper end of the main pipe 2 and stretching radially in a distal direction of a major axis of the main pipe 2, thereby expanding a heating range in a horizontal direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heat pipe that utilizes the heat pipe phenomenon and is made up of multiple pipes connected together. [Background technology]

[0002] (heat pipe) A heat pipe is a hollow metal pipe created by creating a vacuum inside and sealing in a liquid (called a working fluid). When a temperature difference occurs between the two ends of the pipe, the working fluid absorbs heat and evaporates in the high-temperature area, creating a vapor flow to the low-temperature area. The vapor that reaches the low-temperature area then condenses while releasing heat, and the resulting liquid returns to the high-temperature area through the wall. Because the working fluid in a heat pipe repeatedly changes phase and circulates between the high-temperature and low-temperature areas, it can continuously transfer heat until the temperature difference between the two ends of the pipe disappears. There are two mechanisms by which the liquid in a heat pipe returns to the high-temperature part. One is to use gravity (thermosyphon heat pipe), and the other is to use capillary force (wick heat pipe). Both types of heat pipes are driven solely by temperature difference and have high heat transport capacity, so they are used in a wide range of fields, such as snow melting technology using geothermal heat and laptop CPU cooling devices.

[0003] (Prior patent document) Several heat transport devices using heat pipes have been reported, as follows: Patent Document 1 discloses "a heat pipe comprising a vacuum container, a sintered metal body made of copper powder arranged with its outer surface along the inner surface of the vacuum container, and a working fluid sealed inside the vacuum container that evaporates when heated and condenses by releasing heat, characterized in that a flow path for flowing the working fluid is formed at the boundary between the inner surface of the vacuum container and the outer surface of the sintered metal body." Patent Document 2 discloses a heat pipe that "consists of a tubular body that contains a working fluid sealed inside and maintains a vacuum state, and a heating section that has a double tubular recess formed on the base end side of the tubular body, and is characterized by having an increased heating area ratio of the heating section." Patent Document 3 discloses a "heat transport device utilizing the heat pipe phenomenon of soil."

[0004] The above-mentioned prior patent documents do not disclose or suggest the configuration of the heat pipe of the present invention in which a plurality of pipes are connected. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2009-115346 [Patent Document 2] Patent Publication No. 2004-108749 [Patent Document 3] Patent Publication No. 2017-40376 Summary of the Invention [Problem to be solved by the invention]

[0006] Conventional heat pipes that utilize the heat pipe phenomenon are effective in transporting heat vertically from the bottom layer to the surface layer, but because they have a straight pipe shape, the heat that reaches the surface layer has difficulty moving horizontally, and the heating range is limited. [Means for solving the problem]

[0007] The inventors have confirmed that a heat pipe including a main pipe and two or more sub-pipes connected to the upper end of the main pipe and extending radially distally from the longitudinal axis of the main pipe is a heat pipe that can expand the horizontal heating range, which is the above-mentioned problem, and have completed the present invention.

[0008] The present invention is as follows. 1. Heat pipes, including: A main pipe containing hydraulic fluid, and two or more hydraulic fluid-filled sub-pipes, the ends of which are connected to an upper end of the main pipe and extend radially distally from the longitudinal axis of the main pipe; Heat pipe. 2. The heat pipe according to item 1 above, wherein the sub-pipe is S-shaped or L-shaped. 3. The heat pipe according to item 1 above, wherein the sub-pipes are S-shaped or L-shaped and there are four of them. 4. The heat pipe according to any one of items 1 to 3 above, further comprising a service port at the upper end of the main pipe and at the upper end of the sub-pipe. 5. A plant growth kit including one or more heat pipes according to any one of items 1 to 4 above. 6. A method for growing plants using one or more of the heat pipes described in the preceding paragraphs 1 to 4, comprising the following steps: 1) burying at least the ends of the sub-pipes and the main pipe underground; and 2) A process of placing soil containing plant roots into the cavity formed inside two or more sub-pipes. [Effects of the Invention]

[0009] The heat pipe of the present invention has one or more of the following effects. (1) The upper part of the heat pipe has a wide horizontal heating range. (2) The lower part of the heat pipe is capable of high heat absorption. [Brief explanation of the drawings]

[0010] [Figure 1] Heat pipe schematic diagram [Figure 2] Cross-sectional view of the heat pipe (main pipe and two sub-pipes cut) [Figure 3] Schematic diagram of the sub-pipe shape [Figure 4] Illustration of heat pipe usage example [Figure 5] Sub-pipe shape examples [Figure 6] Image analysis results using heat pipes

[0011] The heat pipe of the present invention, in which multiple pipes are connected, will be described in detail below. The drawings shown below are viewed from the front, and the top, bottom, left, and right of the drawings will be referred to as the top, bottom, left, and right of the heat pipe body.

[0012] (Configuration of the heat pipe of the present invention) The heat pipe (1) of the present invention includes the following configuration. The main pipe (2) contains the hydraulic fluid (4). Two or more "sub-pipes (3) containing hydraulic fluid (4)." The ends of the two or more sub-pipes (3) are connected to the upper end of the main pipe (2) and extend radially in the distal direction of the longitudinal axis of the main pipe (2) (in the direction of the arrowhead of arrow 7).

[0013] (Main pipe) The material of the main pipe (2) is not particularly limited as long as it can contain the working fluid (4), and for example, a copper pipe, a stainless steel pipe, etc. can be used. The shape of the main pipe (2) is not particularly limited as long as it can connect the ends (lower side of the drawing) of multiple sub-pipes (3) to the upper end (upper side of the drawing) of the main pipe (2), but for example, a cylindrical shape can be used. When making the main pipe, it is desirable to vacuum seal the hydraulic fluid. The method for connecting the upper end of the main pipe (2) to the ends of the sub-pipes (3) is not particularly limited, but may be, for example, brazing (eg, phosphorus copper brazing), welding, or the like. A service port (6), which is an inlet for filling the hydraulic fluid (4), may be provided at the upper end of the main pipe (2). The pressure inside the main pipe (2) can be reduced through the service port (6).

[0014] (Sub-pipe) The material of the sub-pipe (3) is not particularly limited as long as it can contain the working fluid (4), and for example, a copper pipe or the like can be used. The shape of the sub-pipe (3) is not limited as long as it can connect the end (bottom of the drawing) of the sub-pipe (3) to the tip (top of the drawing) of the main pipe (2) and extends radially in the distal direction of the long axis of the main pipe (2) (in the direction of the arrowhead of arrow 7), but it may preferably be formed in an L-shape (right of Figure 3) or an S-shape (left of Figure 3). The number of sub-pipes (3) is not particularly limited as long as it is two or more, but examples thereof include three, four, five, six, seven, and eight. When creating the sub-pipe, it is desirable to vacuum seal the hydraulic fluid. When the sub-pipe (3) is S-shaped or L-shaped, the heating range (especially the horizontal heating range (arrow 8 in Figure 4)) can be expanded by increasing the bending angle R. The bending angle R is 90° to 180°, and preferably 120° to 150°. A service port (6) may be provided at the upper end of the sub-pipe as an inlet for filling the hydraulic fluid (4). The pressure inside the sub-pipe (3) can be reduced through the service port (6).

[0015] (hydraulic fluid) The working fluid (4) is not particularly limited, and examples thereof include water, ethanol, methanol, acetone, and refrigerant (particularly, HFC134a (1,1,1,2-tetrafluoroethane) which is a substitute for chlorofluorocarbon).

[0016] (Plant growing kit) The plant growing kit of the present invention includes at least the heat pipe of the present invention. The plant growing kit of the present invention aims to grow plants in the inner space (5) formed inside two or more sub-pipes (3) by utilizing a wide heating range in the horizontal direction (arrow 8 in Figure 4). For example, in winter, a tree root zone is placed in the inner space (5) and the tree is grown.

[0017] (Example 1 of the use of the heat pipe of the present invention) As an example of the use of the heat pipe of the present invention (see FIG. 4), the method for growing plants using the heat pipe of the present invention can be exemplified by the following steps, but is not particularly limited thereto. 1) A process of burying the ends of the main pipe (2) and at least the sub-pipe (3) underground, with the main pipe (2) facing downward (underground) and the sub-pipe (3) facing upward. 2) A process of placing soil containing plant roots (tree root zone) in the inner space (5) formed inside two or more sub-pipes (3). By absorbing heat at the lower end of the main pipe (2) and transferring it to the upper end, transferring heat from the main pipe (2) to the sub-pipe (3), and transferring heat from the lower end to the upper end of the sub-pipe (3) and releasing it, geothermal heat can be transported to the surface without electricity, and the entire roots of plants (tree root zone) can be heated.

[0018] (Example 2 of the use of the heat pipe of the present invention) As an example of the use of the heat pipe of the present invention, the method for growing plants using the heat pipe of the present invention can be exemplified by the following steps, but is not particularly limited. 1) A process of burying the sub-pipe (3) and at least the end of the main pipe (2) underground, with the main pipe (2) facing upward and the sub-pipe facing downward (underground). The plurality of sub-pipes (3) enables heat absorption over a wide range, and increases the amount of heat dissipation at the upper end of the main pipe (2).

[0019] The present invention will be described in more detail below with reference to examples. However, the following examples should be regarded as an aid to gain a concrete understanding of the present invention, and the scope of the present invention is not limited by the following examples in any way. Example 1

[0020] (Confirmation of heat transport capacity of S-shaped sub-pipe) The ends of the S-shaped sub-pipe (right side of Figure 5) and the straight sub-pipe (left side of Figure 5) were set to 15°C, and the temperatures at the top ends were measured using thermal image analysis (device name: Flir C2). It was confirmed that the temperature at the top end of the S-shaped sub-pipe was approximately the same as the temperature at the top end of the straight sub-pipe, and therefore an S-shaped sub-pipe was adopted in the following examples. Example 2

[0021] (Confirmation of heating using a heat pipe, an S-shaped sub-pipe) The prototypes shown in Figure 1 and Figure 6 (left) were created to confirm heating. Details are as follows: Main pipe: Copper pipe Diameter: 2.5 cm, Height: 160 cm The end of the main pipe is immersed in a constant temperature water bath at 40°C. Sub-pipes: 4, copper pipes, S-shaped Diameter: 1.9 cm, vertical length: 55 cm, diameter of the inner space formed by the four sub-pipes: 20 cm The ends of the four sub-pipes were brazed with phosphorus copper near the tip of the main pipe. Brazed joint: 30 cm Main pipe and sub-pipe working fluid: Refrigerant (HFC134a) - Inside the main pipe and sub-pipe: Heat pipes were created by vacuum sealing (reducing the pressure inside the pipe and then injecting working fluid).

[0022] When the room temperature was approximately 25°C and the end of the main pipe was heated to 40°C, thermal image analysis (device name: FlirC2) confirmed that the temperature of the four sub-pipes reached approximately 35°C, and that the temperature of the entire inner space formed by them, which was approximately 20 cm in diameter, was approximately 30°C (see Figure 6, right).

[0023] (Comparative Example) Using sub-pipes with S-shaped, spiral, and twisted shapes, thermal image analysis was performed in the same manner as in Example 1. Specifically, the ends of the S-shaped and twisted sub-pipes were set to 10°C. The end of the spiral-shaped sub-pipe was set to 15°C. It was confirmed that the S-shaped sub-pipe had a smaller temperature difference between both ends than the spiral and twisted sub-pipes. The results were 1.5°C difference for the S-shaped sub-pipe (average of four replicates), 3.0°C difference for the spiral type, and 1.6°C difference for the twisted type. That is, it was confirmed that the S-shaped sub-pipe is superior to the spiral-shaped and twist-shaped sub-pipes. [Explanation of symbols]

[0024] 1: Heat pipe 2: Main pipe 3: Sub-pipe 4: Hydraulic fluid 5: The inner space formed inside the sub-pipe 6: Service port 7: Arrow (distal direction of the main pipe's long axis) 8: Arrow (horizontal) R: Bending angle [Industrial Applicability]

[0025] A heat pipe with a wide horizontal heating range can be provided.

Claims

1. A heat pipe, including: A main pipe containing hydraulic fluid, and two or more sub-pipes containing hydraulic fluid, wherein ends of the two or more sub-pipes are connected to an upper end of the main pipe and extend radially in a distal direction of the longitudinal axis of the main pipe, and the sub-pipes are twisted; Heat pipe.

2. A heat pipe as described in claim 1, wherein the working fluid is HFC-134a.

3. 3. The heat pipe according to claim 1, further comprising a service port at an upper end of said main pipe and an upper end of said sub-pipe.

4. A plant growth kit comprising one or more heat pipes according to claims 1 to 3.

5. A method for growing plants using one or more heat pipes according to claims 1 to 3, comprising the following steps: 1) burying at least the ends of the sub-pipes and the main pipe underground; and 2) A step of placing soil containing plant roots in the cavity formed inside the two or more sub-pipes.

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