JP2003302108A - U-tube type geothermal heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a U-tube type geothermal heat exchanger capable of improving heat collecting efficiency by surely eliminating air gap. <P>SOLUTION: Two U-tubes 1 formed in a U-shape are inserted into a vertical hole 3 drilled in the earth with their bottoms stacked vertically. A grout filling pipe 2 is inserted into a central space of the U-tubes 1. Grout 4 is injected through the grout filling pipe 2 to fill up the vertical hole 3, and the two U-tubes 1 are laid underground along with the grout filling pipe 2. The grout 4 is preferably mixed with material of high thermal conductivity. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to snow melting, cooling and heating,
The present invention relates to a U-tube type underground heat exchanger capable of efficiently collecting the underground heat used for a hot water pool, plant cultivation, animal breeding and the like.

[0002]

2. Description of the Related Art In recent years, in consideration of environmental problems such as air pollution, ground heat, which is one of the natural energy that does not cause such problems, is used to perform snow melting or heating / cooling of roads and roofs. Techniques have been developed by the inventors.

In order to collect the underground heat, it is necessary to bury the heat exchanger in the ground and collect it. One of the heat exchangers is a U-shaped one (U-shaped tube). There is a formula).
In this U-shaped tube heat exchanger, the heat medium is supplied from the upper end of one of the passages (first passage), sent directly to the lower side and inverted at the lower end, and the other passage (second passage) is raised. By doing so, the underground heat is collected.

[0004]

This U-tube type heat exchanger has an advantage that the heat collection efficiency is high because underground heat can be collected in both the first passage and the second passage. .

However, since the shape is the U-order formula, unlike the cylindrical concentric double pipe type, for example, not only between the ground and the U-shaped pipe but also the first passage and the second passage. There is also a problem that a gap is generated between the passage and the heat collection efficiency is lowered due to the gap.

The present invention was devised in view of these problems, and an object thereof is to provide a U-tube type underground heat exchanger capable of improving the heat collection efficiency by surely eliminating the voids. To do.

[0007]

Means for Solving the Problems An explanation will be given with reference to FIGS. 1 to 3. The U-shaped underground heat exchanger according to the present invention is U
Insert two U-shaped pipes 1 formed in a letter shape into a vertical hole 3 vertically formed in the ground, with their bottom end portions vertically stacked,
The grout injection pipe 2 is inserted into the central space portion of the U-shaped pipe 1, the grout 4 is injected from the grout injection pipe 2 to crush the vertical hole 3, and the two U-shaped pipes 1 together with the grout injection pipe 2 are crushed. It is buried underground. It should be noted that it is advisable to mix the grout 4 with a substance having high thermal conductivity.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a U-tube type underground heat exchanger according to the present invention is shown in FIGS. 1 to 3. This is to insert two U-shaped pipes 1 formed in a U shape into a vertical hole 3 vertically formed in the ground with their bottom ends being vertically stacked, and to insert the center of the U-shaped pipe 1. The grout injection tube 2 and the vertical hole 3 in the space
Insert it deep enough to reach the bottom of the. Then, from the grout injection tube 2, a grout 4 mixed with a metal piece which is a liquid and has a high thermal conductivity is injected to crush the entire vertical hole 3 without a gap, whereby the two U-shaped tubes 1 are It is buried in the ground together with the grout injection pipe 2.

The U-tube type underground heat exchanger thus formed has the grout 4 between the two U-tubes 1 and the ground 5, and since the void is eliminated, the heat conductivity can be enhanced. Therefore, the underground heat can be efficiently collected by the heat medium (antifreeze liquid) flowing in the U-shaped tube 1. Since the grout 4 has excellent fluidity, the voids in the vertical hole 3 can be surely eliminated.

Further, since the grout injection pipe 2 and the grout 4 are also provided between the first passage 1a and the second passage 1b, the heat conductivity in that portion can be enhanced, and this also contributes to the heat collection efficiency. Can be increased.

Furthermore, in this embodiment, since the metal pieces (copper pieces or the like) having high thermal conductivity are mixed in the grout 4, the underground heat can be collected more efficiently.

Although groundwater is usually accumulated in the vertical hole 3, this groundwater can be removed by the grout 4 to be injected. Further, since the grout 4 injected from the grout injection pipe 2 has excellent fluidity, it is possible to fill not only the bottom portion of the vertical hole 3 but also the upper portion thereof without a gap without applying a large pressure in the grout injection pipe 2. it can.
However, the grout 4 may be injected from the upper end opening of the vertical hole 3 if necessary.

In the present embodiment, the diameter of the vertical hole 3 is 160 mm at the upper part thereof, about 130 mm at the middle part and the lower part thereof, and the depth thereof is about 100 m. The U-shaped pipe 1 is made of a hard polyethylene pipe with an outer diameter of 40 mm, and the grout injection pipe 2 has an outer diameter of 25 mm.
It is also made of rigid polyethylene pipe. Further, the U-shaped pipe 1 has a first passage 1a which is an outward path of a heat medium and a second passage 1b which is a return path, and an upper end portion of the U-shaped tube 1 has a heat radiating mechanism such as a snow melting pipe 7 and an air conditioner via a circulation path 6. Connected to.

The operation of the U-tube underground heat exchanger according to this embodiment will be described by taking the case of snow melting as an example. First, the heat medium radiated by the snow melting pipe 7 is supplied to the first passage 1a of the U-shaped pipe 1 by the circulation pump 8, and the first passage 1a
It is sent down inside. Here, since the first passage 1a is in direct contact with the ground 5 via the grout 4, the heat medium in the first passage 1a efficiently collects underground heat by heat exchange.

This heat medium reverses at its bottom end, advances to the second passage 1b, and rises as it is. Like the first passage 1a, the second passage 1b is also in direct contact with the ground 5 via the grout 4, so that the heat medium in the second passage 1b efficiently extracts underground heat. Moreover, since the grout 4 and the grout injection pipe 2 are also provided in the central portion of the U-shaped pipe 1, there is no gap,
Therefore, this also enables efficient heat collection.

The heat medium which has passed through the second passage 1b is supplied to the snow melting pipe 7 by the circulation pump 8 and releases the collected underground heat to perform snow melting and the like, and then is returned to the first passage 1a again. By repeating such a process, the snow is continuously melted by the underground heat.

In addition to the commercial power source, the circulation pump 8 is
It can be operated by a solar thermal power generator or an internal combustion engine power generator. As shown in FIG. 4, the solar power generation device absorbs sunlight by the solar panel 9, and the storage battery box 10
The storage battery 12 in the control board 11 that operates when charging is required
The electric power is stored via the controller 13, and the controller 13 supplies the necessary amount of electric power to the circulation pump 8.

[0018]

EFFECTS OF THE INVENTION In the U-tube underground heat exchanger according to the present invention, since the vertical hole 3 is crushed by the grout 4, U
It is possible to reliably prevent an unnecessary gap from being formed between the character tube 1 and the ground 5, and to enhance the thermal conductivity of that portion. Therefore, underground heat can be efficiently collected.

Further, by mixing a substance having a high thermal conductivity into the grout 4, the thermal conductivity of the grout 4 can be enhanced, so that the underground heat can be collected more efficiently.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a schematic perspective view showing a lower end portion of the present invention.

FIG. 4 is a flow chart of a solar thermal power generator that operates a circulation pump of an underground heat exchanger according to the present invention.

[Explanation of symbols]

1 U-shaped tube 1a 1st passage 1b Second passage 2 grout injection tube 3 vertical holes 4 grout 5 ground 6 circuit 7 snow melting tubes 8 circulation pumps 9 solar panels 10 storage battery box 11 Control board 12 storage battery 13 Controller

Claims (2)

[Claims] 1. Two U-shaped tubes (1) formed in a U-shape
Is inserted into the vertical hole (3) vertically formed in the ground with the bottom ends thereof vertically stacked, and the grout injection pipe (2) is inserted into the central space of the U-shaped pipe (1). Then, the grout (4) is injected from the grout injection pipe (2) to crush the vertical hole (3), and the two U-shaped pipes (1) are connected to the grout injection pipe (2).
A U-tube underground heat exchanger that is embedded in the ground together with it. 2. The U-tube underground heat exchanger according to claim 1, wherein the grout (4) is mixed with a substance having a high thermal conductivity.