JP2007321383A - Heat-exchange excavated pile and snow-melting equipment utilizing geothermal heat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-exchange excavated pile capable of being constructed even on a narrow site and capable of reducing construction costs without decreasing heat exchange efficiency, and snow-melting equipment utilizing geothermal heat, which can reduce running costs. <P>SOLUTION: In this heat-exchange excavated pile, a pipe-like main body, which is buried in an excavated hole with a predetermined depth, comprises a first channel which supplies a heating medium into the ground from on the ground, and a second channel which warms or cools the heating medium by utilizing the almost constant state of an earth temperature and which returns the warmed or cooled heating medium onto the ground. The cross-sectional area 2a of the first channel is set not greater than 1/2 of the cross-sectional area 2b of the second channel. The main body comprises at least a double pipe 20 which is composed of outer and inner pipes 22 and 21; the inside of the inner pipe serves as the first channel; an annular space, which is formed between the outer and inner pipes, serves as the second channel; the ratio between the outside diameter of the inner pipe and that diameter of the outer pipe is set to be in the range of 0.2-0.6; and the outside diameter of the outer pipe is set no longer than 80 mm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat excavation pile and an underground heat-utilizing snow melting device.

  When the depth of the underground reaches a certain level, the temperature is almost constant throughout the year. Conventionally, a heat medium is circulated through the heat exchanging pile installed in the ground to collect heat from the ground or exhaust heat to the ground. It has already been used for snow melting, air conditioning and hot water supply for ground facilities. For example, a plurality of heat transfer tubes that allow the heat medium to pass through are arranged in the pile circumferential direction in a state extending in the pile longitudinal direction on the outer peripheral surface of the pile, and a band tool is arranged around the heat transfer pipe, and the heat transfer tube is piled by this band tool. A stake attached to the outer peripheral surface is proposed (see Patent Document 1).

  However, since the piles described in Patent Document 1 cannot be constructed without a foundation pile, the ground area where there is no foundation pile or facilities far from the foundation pile, such as general roads in mountainous areas, etc. There is a problem that it cannot be installed.

  Further, in order to solve such problems, a new pile is excavated and the excavated pile is used as a heat exchange pile using underground heat for a snow melting device or the like. For example, a coaxial double-tube heat exchanger that concentrically arranges an inner cylinder inside an outer cylinder, embeds it vertically in the ground, and circulates a liquid medium (heat medium) in it to collect underground heat. A ground heat utilizing snow melting device using (pile) has been proposed (see Patent Document 2).

  However, in the heat exchanger (pile) of the ground heat snow melting device described in Patent Document 2, since a hole for installing the heat exchanger has to be newly excavated, the excavation cost is high and the initial cost is high. In particular, since the diameter of the outer cylinder of the conventional heat exchange pile as described above is a relatively large diameter of about 90 mm or more, the construction cost of the excavation pile that occupies most of the initial cost is high. There is a problem that it ends up. For this reason, it has generally been an obstacle to popularizing heat excavation piles.

  Furthermore, in order to solve such problems, underground heat exchangers (pile) have been proposed that increase the efficiency of heat exchange, shorten the overall length of the heat exchanger (pile), and reduce the installation cost. (See Patent Document 3). In the underground heat exchanger described in Patent Document 3, the ratio of the outer diameter of the inner tube to the inner diameter of the outer tube is 0.70 or more and 0.95 or less, or the inner peripheral surface and / or the inner tube of the outer tube. The surface roughness Ra of the outer peripheral surface of the tube is set to 10 μm or more and 1 mm or less, or the protrusions are continuously disposed on the inner peripheral surface of the outer tube and / or the outer peripheral surface of the inner tube with an interval in the axial direction. Alternatively, a perforated member constructed so as to allow a heat medium to flow between the outer tube and the inner tube is continuously disposed in the gap with an interval in the axial direction. In short, the heat medium is made difficult to flow in the flow path between the outer tube and the inner tube, and the apparent Reynolds number of the heat medium is increased by flowing pressure quickly with a pump therethrough, thereby increasing the heat medium. The heat transfer coefficient is increased.

However, in such underground heat exchangers, although the heat transfer coefficient of the heat medium itself increases, it is necessary to apply high pressure for that purpose, and the pump must be enlarged, and the installation cost and operating cost of the pump must be increased. There is a problem that the running cost increases.
In addition, since such underground heat exchangers are only intended to increase the heat transfer coefficient of the heat medium, not only heat exchange between the underground ground and the heat medium but also the heat flowing in the inner pipe. Less consideration is given to heat exchange between the medium and the heat medium flowing through the flow path between the outer tube and the inner tube. Therefore, it is insufficient to increase the total amount of heat exchange of the entire heat exchanger. In addition, since it is not considered to reduce the diameter of the heat exchanger, the excavating machine cannot be reduced in size, it cannot be constructed in a narrow area where a large excavating machine cannot be carried in, and most of the initial cost is There is also a problem that it is insufficient to reduce the construction cost of the heat exchanger (pile) occupying.

JP 2003-206528 A JP 2003-301409 A JP 2004-309124 A

  Accordingly, the present invention solves the problems of the conventional technology, can be constructed even in a small area, and can reduce the construction cost without reducing the heat exchange efficiency, An object of the present invention is to provide a ground heat-utilizing snow melting device that can be reduced.

  In order to solve the above-described problem, in the heat excavation pile according to the first aspect of the present invention, a tubular main body is embedded in an excavation hole having a predetermined depth, and the main body is heated from the ground toward the ground. A heat exchange excavation pile having a first flow path for feeding and a second flow path for warming or cooling the heat medium and returning it to the ground by utilizing the fact that the temperature in the ground is substantially constant The cross-sectional area of the first flow path is set to ½ or less of the cross-sectional area of the second flow path.

  The heat excavation pile according to the invention of claim 2 is the invention according to claim 1, wherein the main body is composed of at least a double pipe of an outer pipe and an inner pipe, and the inside of the inner pipe serves as the first flow path. The annular space formed between the outer tube and the inner tube serves as the second flow path, and the ratio of the outer diameter of the inner tube to the outer diameter of the outer tube is set to 0.2 to 0.6. It is characterized by.

  The heat excavation pile according to the invention described in claim 3 is the invention according to claim 2, wherein the outer diameter of the outer pipe is less than 80 mm so that turbulent flow is easily generated in the heat medium. Features.

  The heat excavation pile according to the invention of claim 4 is the invention according to claim 2 or 3, wherein the outer pipe increases the surface area in contact with the heat medium flowing through the second flow path to increase the heat exchange efficiency. In order to improve the above, the outer surface and / or the inner surface is formed into a wave shape or an uneven shape.

  The heat excavation pile according to the invention of claim 5 is the heat medium flowing in the second flow path on the inner surface of the outer tube and / or the outer surface of the inner tube in the invention of any one of claims 2 to 4. Protrusions for generating turbulent flow to improve heat exchange efficiency are provided.

  The heat excavation pile according to the invention of claim 6 is the invention according to any one of claims 2 to 5, wherein the main body has a plurality of spacers for fixing the inner pipe in a predetermined position in the outer pipe in the longitudinal direction. The spacer is formed in a spiral plate shape so as to turbulently flow the heat medium flowing through the second flow path.

  A snow-melting snow device according to a seventh aspect of the present invention includes the heat exchange excavation pile according to any one of the first to sixth aspects.

  A snow-melting snow device according to an eighth aspect of the present invention is a heat exchange excavation pile according to any one of the first to sixth aspects, a heat exchange pipe embedded in a snow pin pavement in a snow melting pavement on the surface, A first communication path connected so that one end of the pipe and the first flow path of the excavation pile communicate with each other; a second communication path connected so that the other end of the pipe communicates with the second flow path of the excavation pile; The second communication path and the heat medium cooled by the heat exchange pipe are supplied to the first flow path, and the heat medium heated in the ground is returned from the second flow path to the heat exchange pipe. And a pump that operates as described above.

  This invention is as described above. According to the heat excavation pile according to the invention of claim 1, the cross-sectional area of the first flow path is ½ or less of the cross-sectional area of the second flow path. In other words, since the cross-sectional area of the second flow channel is set to be larger than the cross-sectional area of the first flow channel, The flow rate of the second flow path in contact with the ground can be reduced to less than half, and the time for heat exchange between the ground and the heat medium in the ground can be taken slowly. The heat medium flowing in the first flow path that is less and does not exchange much heat with the ground in the ground, and the heat medium in the second flow path that is heat exchanged with the ground in the ground There is an excellent effect that the contact area between and can be reduced, and the heat loss between them can be reduced. Therefore, the diameter of the heat excavation excavation pile can be reduced without reducing the heat exchange efficiency, and the construction cost can be reduced while being able to be constructed even in a narrow area.

  According to the heat excavation pile according to the invention described in claim 2, the main body is composed of at least a double pipe of the outer pipe and the inner pipe, the inside of the inner pipe becomes the first flow path, and the space between the outer pipe and the inner pipe. The annular space formed in the second channel is the second flow path, and the ratio between the outer diameter of the inner pipe and the outer diameter of the outer pipe is set to 0.2 to 0.6. The two flow paths of the pile can be configured from a single double pipe, and the heat excavation pile can be reduced in diameter without reducing the efficiency of heat exchange. Therefore, it can be constructed even in a narrow area, and the construction cost of the pile can be reduced.

  According to the heat excavation pile according to the invention of claim 3, the outer diameter of the outer pipe is less than 80 mm so that turbulent flow is easily generated in the heat medium. Therefore, the construction cost of the heat excavation excavation pile, which occupies most of the initial cost, can be reduced.

  According to the heat excavation pile according to the invention of claim 4, the outer pipe has an outer surface and / or an outer surface in order to increase the surface area in contact with the heat medium flowing through the second flow path and improve the heat exchange efficiency. Since the inner surface is formed into a wave shape and irregularities, the surface area in contact with the heat medium flowing through the second flow path is increased, and the efficiency of heat exchange between the ground and the heat medium is improved. To do.

  According to the heat excavation pile according to the invention described in claim 5, heat exchange efficiency is improved by generating turbulent flow in the heat medium flowing through the second flow path on the inner surface of the outer tube and / or the outer surface of the inner tube. Therefore, the flow of the heat medium in the second flow path can be turbulent, the heat transfer rate of the heat medium is increased, and the heat between the ground and the heat medium in the ground is increased. Exchange efficiency can be improved.

  According to the heat excavation pile according to the invention described in claim 6, the main body is provided with a plurality of spacers at predetermined intervals in the longitudinal direction for fixing the inner pipe to a predetermined position in the outer pipe. Since the heat medium flowing in the second flow path is formed in a spiral plate shape to turbulently flow, the flow of the heat medium in the second flow path can be turbulent and the heat of the heat medium The transmission rate is increased, and the efficiency of heat exchange between the underground ground and the heat medium can be improved.

  According to the snow-melting snow device according to the invention described in claim 7, since the heat excavation pile according to any one of claims 1 to 6 is provided, the snow-melting snow according to the invention according to claim 8 is also provided. According to the apparatus, the heat exchanging excavation pile according to any one of claims 1 to 6, a heat exchanging pipe embedded in a snow-covered pavement on the ground surface, and one end of the pipe and the excavation pile A first communication path connected so that one flow path communicates, a second communication path connected so that the other end of the pipe communicates with a second flow path of the excavation pile, and A pump that feeds the heat medium cooled by the heat exchange pipe to the first flow path and operates to return the heat medium warmed in the ground from the second flow path to the heat exchange pipe; Therefore, the heat excavation pile according to any one of claims 1 to 6 can be used as a snow melting device. Can.

  An embodiment of the present invention will be described with reference to the drawings. This embodiment shows the case where a heat exchange excavation pile is used as a non-sprinkling snow-melting device in winter.

  Drawing 1 is an outline figure showing the outline of the whole snow melting apparatus provided with the heat exchange excavation pile concerning an embodiment. 1 is a snow-melting snow device, and 2 is a heat excavation pile. The snow-melting snow device 1 exchanges heat between the heat medium flowing in the pile and the surrounding ground in the heat excavation pile 2 and heat energy is applied to the snow-melting pavement 3 installed on the ground surface with the heat medium. This is a device that melts and melts snow when the snowmelt pavement 3 freezes and accumulates snow, and is used for road surfaces such as tunnel exits and chain desorption places, public facilities such as stations, and commercial facilities such as supermarkets.

  The snow melting device 1 is formed in a hairpin curve shape embedded in a so-called coaxial double tube heat exchange excavation pile 2 composed of an inner tube 21 and an outer tube 22 and a snow melting pavement 3 that performs snow melting. It has a heat exchange pipe 4. The inner pipe 21 and one end of the heat exchange pipe 4 communicate with each other through the pipe 5 that is the first communication path, and the outer pipe 22 and the other end communicate with each other through the pipe 6 that is the second communication path. The annular space formed between the outer tube 22 and the inner tube 21 is the second channel, and the inner space of the inner tube 21 is formed in the direction of the arrow in the figure. The heat medium is circulated by pressure. In addition, circulating water is used as the heat medium according to this embodiment. However, the heat medium may be a fluid, and generally, a liquid such as water or an antifreeze liquid or a gas such as air is used. In addition, although the heat exchange pipe 4 was used here as a pipe embed | buried in the snowmelt pavement 3, a heat pipe can also be used.

  As shown by the arrows in FIG. 1, the circulating water heated by exchanging heat with the surrounding ground in the heat excavation pile 2 is heated and pumped by the pump 7, passes through the pipe 6, and passes through the heat exchange pipe. 4 is reached, heat exchange with the snowmelt pavement 3 is performed, and the snowmelt pavement 3 is warmed to perform snow melting. Then, the circulating water cooled by heat exchange with the snow melting pavement 3 passes through the pipe 5 and returns to the inner pipe 21 of the heat exchange excavation pile 2, and heat exchange with the underground ground again by the heat exchange excavation pile 2. Is done and warmed up. That is, the first flow path (inner pipe 21) → second flow path (annular space formed between the outer pipe and the inner pipe) → second communication path (pipe 6) → first communication path ( Pipe 5) is configured so that the circulating water circulates in the sealed tube in the order of the first flow path. Thus, since the circulating water is circulated and used, the necessary running cost is about the electricity cost of the pump, which is extremely economical as compared to the watering type snow melting device. Moreover, it is excellent also in terms of maintenance, such as that inspection of the ejection nozzle is unnecessary.

  The snow-melting device 1 described above is only a preferable example, and is not limited to the case of using one type of heat medium in a circulating manner, but with another heat medium by interposing a heat storage device (heat pump) or the like in the middle. The snow melting pavement may be warmed. If it does in this way, since heat can be stored and used, underground heat can be used more effectively.

  As shown in FIG. 2, the heat exchange excavation pile 2 is a so-called coaxial double pipe type heat exchange pile having a double pipe 20 in which an inner pipe 21 is arranged coaxially in an outer pipe 22, and newly excavated. It is a type of excavation pile that excavates a hole and installs a double pipe 20 as a tubular main body there. This excavation hole is generally excavated vertically to a depth of about 40 m to 100 m, depending on the area of the snow melting pavement 3 where snow melting should be performed. Moreover, the double pipe 20 which is the main body of the heat excavation pile 2 is set to a length according to the depth of the excavation hole, and is fixed vertically by hardening the outer periphery of the pipe with a grout material or the like in the excavation hole. Buried. The double pipe 20 is installed in an outer pipe 22 having a bottom end cap 22a provided at the lower end so that an inner pipe 21 as an open bottom pipe is coaxial with the outer pipe 22 by a spacer 23. . A plurality of spacers 23 are provided at a predetermined interval in the longitudinal direction of the double tube 20, and the inner tube 21 is fixed in the outer tube 22 while maintaining the interval, and an antifreeze liquid can be circulated. Yes. As long as the antifreeze can be circulated, the structure of the spacer 23 can be arbitrary.

  As shown in FIG. 3, the outer tube 22 is composed of a vinyl chloride pipe (VP tube having a nominal diameter of 50) having an outer diameter of 60 mm, and the inner tube 21 is a vinyl chloride pipe (nominal diameter of 25 mm) having an outer diameter of 32 mm. VP tube). That is, the ratio (2a / 2b) between the cross-sectional area 2a of the inner pipe 21 serving as the first flow path and the cross-sectional area 2b of the annular space between the inner pipe 21 and the outer pipe 22 serving as the second flow path. The ratio of the outer diameter of the inner pipe to the outer diameter of the outer pipe is set to 0.53, that is, 0.2 to 0.6. (The cross-sectional areas 2a and 2b are indicated by hatching in FIG. 3). Moreover, the outer diameter of the double pipe which is the main body of the heat excavation pile 2, that is, the outer diameter of the outer pipe 22 is set to be less than 80 mm.

Thus, by setting the ratio of the cross-sectional area 2a and the cross-sectional area 2b to ½ or less, the flow rate of the second flow path is reduced by about twice as much as the flow speed of the first flow path. Heat exchange time between the ground and the heat medium can be taken slowly (more than twice). For this reason, the total amount of heat exchange between the heat medium and the underground ground can be increased, in other words, the temperature increase of the heat medium per unit time can be increased, and the heat exchange as a whole of the heat excavation pile 2 Can increase the efficiency. In addition, a heat medium flowing in the first flow path in which heat exchange with the underground ground is not performed, and a heat medium in the second flow path in which heat exchange with the underground ground is performed Since the contact area between the two can be reduced, the heat exchange between them can be reduced, and the heat loss can be reduced.
And by making the pipe diameter of the heat excavation pile 2 small diameter less than 80 mm, it becomes easy to generate | occur | produce a turbulent flow in a heat medium, and the efficiency of heat exchange improves by generating such a turbulent flow.

  Further, by setting the ratio of the outer diameter of the inner tube and the outer diameter of the outer tube to 0.6 or less, the same effect as making the ratio of the cross-sectional area 2a and the cross-sectional area 2b to 1/2 or less is obtained. can get. Here, if the ratio of the outer diameter of the inner tube to the outer diameter of the outer tube is a small diameter of less than 0.2, the inner tube diameter becomes too small because the outer diameter of the outer tube is less than 80 mm. There is a possibility that the flow in the inner pipe, that is, the flow of the second flow path may be hindered. For this reason, the ratio between the outer diameter of the inner tube and the outer diameter of the outer tube is preferably 0.2 to 0.6.

  In addition, although the example which comprises the double pipe 20 by a vinyl chloride pipe was shown as mentioned above, the double pipe 20 may be other resin pipes, such as a polyethylene pipe, and metal pipes, such as an iron pipe and a copper pipe. It does not matter, that is, it should just be comprised from the strong tubular body. Further, by making the inner tube 21 a tube having a low thermal conductivity and the outer tube 22 a tube having a high thermal conductivity, the efficiency of heat exchange between the underground ground and the heat medium is increased and the first flow is improved. Since heat loss due to heat exchange between the path and the second flow path can be suppressed, the heat exchange efficiency of the heat excavation pile 2 as a whole can be further improved.

  FIG. 4 is a cross-sectional plan view showing a modification of the heat exchange excavation pile. The heat excavation pile 2 shown in FIG. 3 is different from the heat excavation pile 2 only in the outer tube 22 '. Therefore, explanations other than the outer tube 22 'are omitted. As shown in the figure, the outer tube 22 'has a deformed shape whose outer peripheral surface and inner peripheral surface are formed in a corrugated shape along the circumferential direction so as to increase the surface area in contact with the heat medium flowing through the second flow path. It is a tube. For this reason, while increasing the surface area which contacts the heat medium which flows through a 2nd flow path, the surface area of outer pipe 22 'by the side of the ground which is a heat source can be enlarged, and the inside of a 2nd flow path can be increased. The efficiency of heat exchange between the flowing heat medium and the ground in the ground is further improved.

  FIG. 5 is a cross-sectional plan view showing still another modification of the heat excavation pile. The only difference from the heat excavation pile 2 shown in FIG. 3 in terms of its configuration is that the outer tube 22 is provided with a protrusion 22b. Therefore, other explanations are omitted. As shown in the figure, a plurality of protrusions 22b are fixed to the inner peripheral surface of the outer tube 22 at predetermined intervals in the circumferential direction and the longitudinal direction. For this reason, the heat medium flowing through the second flow path flows while colliding with the protrusions 22b protruding substantially perpendicular to the flowing direction, and thus becomes turbulent. Then, the heat transfer coefficient of the heat medium increases, and the heat exchange efficiency of the heat excavation pile 2 as a whole is improved.

  FIG. 6 is a perspective view showing a modified example of the spacer. As shown in the drawing, the spacer 23 ′ includes a shaft portion 23 a ′ inscribed in the outer peripheral surface of the inner tube 21, an outer peripheral portion 23 b ′ in contact with the inner peripheral surface of the outer tube 22, and the shaft portion 23 a ′ and the outer peripheral portion. And a spiral plate portion 23c ′ formed in a spiral shape with a plate-like body spanned between 23b ′. For this reason, the inner tube 21 can be fitted into the shaft portion 23a ′ and firmly supported by the outer peripheral portion 23b ′ in the outer tube 22, and the heat medium flowing in the second flow path can be guided by the spiral plate portion 23c. It is possible to forcibly turbulently flow along 'and further improve the efficiency of heat exchange of the heat excavation pile 2.

As described above, the case where the heat excavation pile 2 is used as the snow-melting snow device 1 in winter has been described as an example. However, as a heat island countermeasure, the heat excavation pile 2 may be used as a device for cooling a pavement or the like in summer. . In this case as well, the configuration shown as the snow-melting snow device 1 may be exactly the same, and the flow of the heat medium is also the same. However, in the summer, the surface temperature of the pavement shown as the snow melting pavement 3 on the surface is higher than the underground ground temperature in reverse with the winter season, so the pavement is heated via the heat medium in the underground ground. The body can be cooled.
By the way, if the heat exchanging excavation pile 2 is continuously used as a snow melting device 1 only in winter, the cold air exchanging heat with the ground surface will accumulate in the ground, and the ground temperature around the pile will change over time. A phenomenon of gradual decrease occurs. However, by using the heat excavation pile 2 as a cooling device in the summer as described above, it is possible to reduce or eliminate the aging of the ground temperature around the pile as described above.

  In addition, in the said embodiment, the shape, structure, etc. of members, such as the heat exchange excavation pile 2 shown by drawing etc., the double pipe 20 as a structural member of this pile, and spacers 23 and 23 ', are a preferable example to the last. In the implementation, design changes and modifications can be arbitrarily made within the scope of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole schematic diagram which shows the snow-melting snow apparatus which is one embodiment of this invention. It is a longitudinal front view of a heat exchange excavation pile same as the above. It is an expansion cross-sectional top view of a heat excavation excavation pile same as the above, and shows the cross-sectional area of a 1st flow path, and the cross-sectional area of a 2nd flow path. It is an expansion cross-sectional top view similar to FIG. 3 which shows the modification of a heat excavation pile. It is an expanded transverse plan view similar to FIG. 3 which shows another modification of a heat excavation pile. It is a perspective view which shows the modification of a spacer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Snow-melting apparatus 2 Heat exchange excavation pile 3 Snow melting pavement 4 Heat exchange pipe 7 Pump 20 Double pipe 21 Inner pipe 22 Outer pipe 23,23 'Spacer

Claims (8)

A tubular main body is embedded in an excavation hole of a predetermined depth, and the main body utilizes the first flow path for supplying the heat medium from the ground to the ground and the temperature in the ground is substantially constant. A heat excavation pile having a second flow path for heating or cooling the heat medium and returning it to the ground,
The heat exchange excavation pile, wherein the cross-sectional area of the first flow path is set to ½ or less of the cross-sectional area of the second flow path.   The main body is composed of at least a double tube of an outer tube and an inner tube, the inner tube serves as a first flow path, and the annular space formed between the outer tube and the inner tube serves as a second flow path. A heat excavation pile according to claim 1, wherein the ratio of the outer diameter of the inner pipe to the outer diameter of the outer pipe is set to 0.2 to 0.6.   The heat exchange excavation pile according to claim 2, wherein an outer diameter of the outer pipe is less than 80 mm so that a turbulent flow is easily generated in the heat medium.   The outer tube is formed in a wave shape or an uneven shape on the outer surface and / or the inner surface in order to increase the surface area in contact with the heat medium flowing through the second flow path and improve the heat exchange efficiency. The heat excavation pile as described in 2 or 3.   5. A projection for improving heat exchange efficiency by generating turbulent flow in the heat medium flowing through the second flow path on the inner surface of the outer tube and / or the outer surface of the inner tube. Heat exchange excavation pile as described in.   The main body is provided with a plurality of spacers at predetermined intervals in the longitudinal direction for fixing the inner tube at a predetermined position in the outer tube, and the spacer turbulently heats the heat medium flowing through the second flow path. The heat excavation pile according to any one of claims 2 to 5, wherein the pile is formed in a spiral plate shape.   A ground heat-utilizing snow melting device comprising the heat excavation pile according to any one of claims 1 to 6.   A heat exchange excavation pile according to any one of claims 1 to 6, a heat exchange pipe embedded in a snowpin pavement on the surface of the snow melting pavement, an end of the pipe, and a first flow path of the excavation pile The first communication passage connected so as to communicate, the second communication passage connected so that the other end of the pipe and the second flow path of the excavation pile communicate, and cooling with the heat exchange pipe And a pump that operates to send the heated heat medium to the first flow path and return the heat medium heated in the ground from the second flow path to the heat exchange pipe. Ground-melting snow melting equipment.

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