JP2017101867A - Geothermal heat exchanger and heat pump system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger using a vertical buried geothermal heat exchange structure increased in heat exchanging efficiency in comparison with a conventional vertical buried geothermal heat exchange structure and improved in workability, and a heat pump using the same.SOLUTION: A geothermal heat exchanger includes a geothermal heat exchange structure in which a plurality of resin fluid passages having going passages for allowing a circulated fluid to flow from a ground surface side toward the underground, and returning passages for allowing the fluid having passed through the going passage to flow from the underground toward the ground surface side in a heat exchange region formed from the ground surface vertically downward, as a fluid passage for allowing the circulated fluid to exchange heat with the ground, a group of the fluid passages are bundled while substantially kept into contact with the adjacent fluid passages, the other group of the fluid passages are disposed at intervals from the adjacent fluid passages, and one group of the fluid passages and the other group of fluid passages are respectively configure the going passages and the returning passages. A heat pump using the geothermal heat exchanger, is also provided.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vertical buried underground heat exchanger and a heat pump system using the same. More specifically, the present invention relates to an underground heat exchanger having an underground heat exchange structure formed from a plurality of resin fluid paths and a heat pump system using the underground heat exchanger.

  The underground temperature is almost constant at 10 to 15 ° C. throughout the year, and is lower in summer and higher in winter than the outside air temperature. Therefore, in order to use the temperature difference from the outside air, a heat exchanger is buried in the ground and the ground heat is collected and used as a heat source. Proposals have been made.

  This underground heat utilization technology uses ground heat, which is almost constant in the ground, to perform heat exchange. In the winter, it is used as a high-temperature energy source for heating or for melting snow. Heat can be collected and used. In summer, geothermal heat can be used as a heat source for cooling as low-temperature energy. Geothermal heat is an efficient heat source because its temperature is more stable than the atmosphere, and it is a heat source that generates less carbon dioxide. Has been.

  As such a ground heat utilization system, a system in which a heat exchange tube is installed vertically in the ground is known. The underground heat exchange tube system installed vertically has the characteristics that the ground surface area occupied for installation is small and the heat loss of the ground surface is small. As an underground heat exchange tube system installed vertically, one or two sets of steel U-tubes or plastic U-tubes with a diameter of several tens of millimeters are inserted into vertical excavation holes, and the surrounding soil material (grouting material) ). For example, Patent Document 1 proposes to use a U-shaped tube in which the lower ends of parallel straight tube portions communicate with each other as a U-shaped tube.

  However, in order to efficiently use the underground heat in the vertically installed underground heat exchange tube system, it is necessary to embed the heat exchange tube deep into the ground, and the drilling depth for embedment is several tens of meters. A depth of ~ 100m was required. Therefore, the long vertical buried underground heat exchanger has a problem that the excavation cost is high and the installation cost is high.

  Proposals have also been made to reduce drilling costs by making the drilling depth shallower. For example, in Patent Document 2, it is proposed that an outward pipe of a pipe buried vertically is a spiral fluid path. However, in order to form the spiral fluid path by blow molding or the like, complicated and precise molding of the pipe is required. On the other hand, in order to process a straight pipe into a spiral shape, it is difficult to perform processing including holding the spiral shape, and the manufacturing cost increases. Furthermore, when the fluid path is spiral, there is a high possibility that a part of the vertical gap between the spiral-formed fluid paths will be narrowed during embedding, and the heat exchange efficiency with the ground may be reduced.

Therefore, as an underground heat exchange structure with improved heat exchange efficiency, the present applicant lays resin pipes that form a plurality of forward paths and return paths with a space between resin pipes that are adjacent forward paths or return paths. Proposed a ground heat exchange structure (Patent Document 3). The underground heat exchange structure proposed in Patent Document 3 can reduce the excavation cost compared to the conventional long vertical buried underground heat exchanger, but it is laid with a gap between the resin pipes. There was a work request to have to.
The present invention has been achieved as a result of studies to further increase the heat exchange efficiency of the underground heat exchange structure proposed in the patent document.

Japanese Patent Laid-Open No. 11-182943 JP 2007-315742 A JP 2014-185822 A

The present invention solves the above-mentioned conventional problems, and realizes a heat exchanger using a vertical buried underground heat exchange structure that realizes high heat exchange efficiency, can significantly reduce excavation costs, and has excellent workability. provide.
The present invention provides a heat exchanger using a vertical buried underground heat exchange structure with improved heat exchanging efficiency and improved workability as compared with a known vertical buried underground heat exchange structure.
The present invention further provides a heat pump using a heat exchanger that can realize high heat exchange efficiency.

  In the heat exchange region formed downward in the direction perpendicular to the ground surface, the present invention passes as a fluid path for circulating the circulating fluid from the ground side to the ground as a fluid path for exchanging the circulating fluid to the ground, and through the forward path. A plurality of resin fluid paths having return paths for flowing fluid from the ground to the ground surface side are bundled so that a group of fluid paths are almost in contact with adjacent fluid paths, and the other groups of fluid paths are And a ground heat exchanging structure that is disposed with a gap between adjacent fluid paths, and in which the one group of fluid paths and the other group of fluid paths form an outward path or a return path, respectively. Provide a ground heat exchanger.

  The above-described underground heat exchanger, in which the bundled bundle of fluid paths is a return path, is a preferred embodiment of the present invention.

  The above-mentioned underground heat exchanger in which the other group of fluid paths maintains an interval of at least 6 cm as the distance between the tube centers between the adjacent fluid paths is a preferred embodiment of the present invention.

  The above-mentioned underground heat exchanger in which the number of resin fluid paths forming the underground heat exchange structure is 3 to 8 is a preferred embodiment of the present invention.

  The above-described underground heat exchanger in which the contact points of the forward path and the return path of the resin fluid path are in the region where the depth is substantially the same is a preferable aspect of the present invention.

  The above-mentioned underground heat exchanger in which the resin fluid path is a U-shaped pipe made of a straight resin pipe is a preferred embodiment of the present invention.

  When a circle is drawn in plan view in the heat exchange region at a position in the middle in the vertical direction of the fluid path, the bundled fluid path and the other group of fluid paths are arranged in the vicinity of the circle. The above-described underground heat exchanger is a preferred embodiment of the present invention.

  The above-described underground heat exchanger, in which the underground heat exchange structure includes an interval holding member that holds the interval of the fluid path at a predetermined interval, is a preferred aspect of the present invention.

  The present invention also provides a geothermal heat pump system having the above-described underground heat exchanger as a heat exchange device.

The present invention makes it possible to shorten the drilling depth to a fraction of that of a long vertical buried underground heat exchanger while realizing high heat exchange efficiency, and vertical burying that can greatly reduce excavation costs A ground-type heat exchanger is provided.
According to the present invention, there is provided a vertical buried underground heat exchange structure with improved heat exchanging efficiency and improved workability as compared with a known vertical buried underground heat exchange structure.
When using a vertical buried underground heat exchanger as a heat exchanger for a load device such as a heat pump, a significant percentage of the installation cost is excavation cost for installing the underground heat exchanger. Therefore, the installation cost can be greatly reduced.
According to the present invention, there is provided a heat pump using a vertical buried underground heat exchanger that can greatly reduce excavation cost and improve workability while realizing high heat exchange efficiency.

It is the schematic which shows the structure of the vertical burying type underground heat exchanger of this invention. It is a photograph which shows the outline which shows the example of arrangement | positioning of the fluid path of this invention. It is the schematic which shows the other example of arrangement | positioning of the fluid path of this invention. It is the cross-sectional schematic which shows the example which attached the space | interval holding member to the fluid path of this invention. It is the schematic which shows a mode that a fluid path turns up in the lower end part of the underground heat exchange structure of this invention. It is the cross-sectional schematic which shows the other example which attached the space | interval holding member to the fluid path of this invention. It is the schematic which shows the other example of arrangement | positioning of the fluid path of this invention. It is the schematic which shows the heat pump using the vertical burying type underground heat exchanger of this invention.

  In the heat exchange region formed downward in the direction perpendicular to the ground surface, the present invention passes as a fluid path for circulating the circulating fluid from the ground side to the ground as a fluid path for exchanging the circulating fluid to the ground, and through the forward path. A plurality of resin fluid paths having return paths for flowing fluid from the ground to the ground surface side are bundled so that a group of fluid paths are almost in contact with adjacent fluid paths, and the other groups of fluid paths are And a ground heat exchanging structure that is disposed with a gap between adjacent fluid paths, and in which the one group of fluid paths and the other group of fluid paths form an outward path or a return path, respectively. A ground heat exchanger is provided.

  The heat exchanging region of the present invention is a region in which a hole excavated downward from the ground surface is backfilled with a filler such as a soil material. The excavation hole is an underground hole that has been backfilled with filler after an underground heat exchange structure is installed in a hole formed by a conventionally known method such as drilling by boring or drilling using a screw auger. This is a region where heat exchange is performed.

  As the filler, it is preferable to use a material having good material thermal conductivity. For example, the filler is composed of a material containing at least one selected from excavated soil, sandy soil, gravelly soil, organic soil, gravel and crushed stone. Soil materials are preferably used. In the heat exchange area, rainwater and groundwater flowing in the ground permeate between the filler particles filled in the excavation part, and the groundwater promotes heat exchange between the underground heat exchanger and the ground.

  The resin-made fluid path is a fluid path that allows a circulating fluid such as antifreeze (brine) and water to flow and exchange heat with underground heat, and exchanges the circulating fluid with ground heat. The resin-made fluid path of the present invention is a fluid path for exchanging the circulating fluid with respect to the ground, an outward path for flowing the circulating fluid from the ground side toward the ground, and a fluid passing through the forward path from the ground toward the ground side. It has a return path to flow, and is preferably a tubular body.

Examples of the resin constituting the resin fluid path include polyolefins such as polyethylene, polypropylene, and polybutene, polyvinyl chloride, and polyamide. Of these, polyolefin pipes, particularly ethylene pipes are particularly preferred.
The contact point between the forward path and the return path of the resin fluid path is at the lower end, and the fluid paths that form the forward path and the return path communicate with each other at the lower end. The fluid path is bent and folded at the lower end. The bent portion may be via an elbow, but a structure in which a single tube is bent and folded is preferable. This is because if there is a fused or bonded portion of the tube, the circulating fluid is likely to leak from there. Such a fluid path is preferably a U-shaped tube.

  The underground heat exchange structure of the present invention is desirably formed by using at least 3, preferably 3-8, more preferably 3 or 4, and especially 4 resin fluid paths.

  In the present invention, in a heat exchange region formed vertically below the ground surface, as a fluid path for exchanging the circulating fluid to the ground, an outward path for flowing the circulating fluid from the surface side toward the ground, and passing through the outbound path A plurality of resin fluid paths having return paths through which the fluid flows from the ground toward the ground surface side are provided.

  Among the fluid paths, a group of fluid paths are bundled so as to be in close contact with an adjacent fluid path, and another group of fluid paths is arranged with an interval between adjacent fluid paths, One group of fluid paths and the other group of fluid paths form an outward path or a return path, respectively. A fluid path that constitutes a group of fluid paths and a fluid path that constitutes another group of fluid paths are in communication with each other, and the circulating fluid fed into the fluid path is a fluid path that constitutes a group of fluid paths; It passes through both other groups of fluid paths and returns to the surface. Any group of one group of fluid paths and another group of fluid paths can act as forward or return paths, but any group can be responsible for forward and return paths. In particular, it is preferable that the group of bundled fluid paths is a return path.

  When the bundle of bundled fluid paths is a return path, the outer surface area of the fluid path that comes into contact with the heat exchange region is reduced by bundling. As a result, the heat of the circulating fluid that is heat-exchanged using underground heat is deprived. Since the amount can be reduced, the amount of heat of the circulating fluid subjected to heat exchange can be maintained.

It is preferable that the bundled group of fluid paths are arranged so as to be substantially in contact with the adjacent fluid paths. The arrangement form may be arranged side by side, and, for example, when there are three groups of fluid paths, a single fluid path is almost in contact with a plurality of fluid paths. May be arranged in a square shape.
“Substantially contact” refers to a positional relationship in which the interval is not too wide, and usually refers to a relationship in which the interval is within 1 cm, preferably within 5 mm.

  The other groups of fluid paths in the present invention are arranged with an interval between adjacent fluid paths. The other group of fluid paths is preferably the outbound path. If the distance between the fluid paths of the other groups is too short, the amount of filler in the heat exchange region that is the heat exchange target is relatively reduced, and the heat exchange efficiency may be reduced.

  In Patent Document 2, as shown in FIG. 4, it has been proposed to lay two fluid paths in the laying area. Since the distance between the channels is shortened, it is difficult to improve the total heat exchange efficiency when the total extension distance of the fluid channel is increased, and the other channel part is laid in the area of the spiral channel. Therefore, heat is taken away from the fluid in the flow path after heat exchange, and it is difficult to obtain high heat exchange efficiency.

  When the outbound path passes near the return path, the amount of filler in the heat exchange area around the outbound path rises or falls due to heat exchange with the circulating fluid in the outbound path. There is a danger that heat will be taken from the circulating fluid of the return path where heat is removed from the circulating fluid, and the temperature change is large depending on the season in the part up to about 5 m deep from the ground surface. However, it is possible to reduce the amount of heat taken from the circulating fluid by bundling the return path.

  In the present invention, by using a plurality of resin fluid paths, the total extension distance of the fluid paths can be extended, and high total heat exchange efficiency can be obtained. This kind of underground heat exchange structure can realize high heat exchange efficiency even if the drilling depth is shortened to a fraction of a few, so it is excavated from a conventionally known long vertical buried underground heat exchanger. It is possible to provide a vertical buried underground heat exchanger that greatly reduces costs.

  In the present invention, as the distance between the fluid paths of other groups, the distance between adjacent resin fluid paths is 6 cm or more, preferably 7 cm or more, more preferably 9 cm, more preferably 11 cm as the distance between the tube centers. It is preferable that they are installed at intervals of about the above.

  In the present invention, when installing the resin-made fluid paths, the group of fluid paths are bundled, and therefore, by fixing the position of the group of fluid paths, the other fluid paths are arranged at a predetermined interval. Is easy and excellent workability is obtained. The present invention exhibits excellent workability in installing a resin fluid path.

  In order to install the resin-made fluid paths at a predetermined interval, an interval holding member can be used. There is no restriction | limiting in particular in the shape of a space | interval holding member, What is necessary is just a shape which can achieve a predetermined objective. For example, it has a holder extending from a circular base material surrounding a resin fluid path, and has a shape surrounding a group of fluid paths arranged in a bundle with the holder, and each of the other groups of fluid paths You may employ | adopt the holder which is formed in the thing of the shape which surrounds.

  In the plurality of fluid paths of the present invention, it is convenient for handling and burying work of the underground heat exchange structure that the contact points of the forward path and the return path of the resin fluid path are in the same depth region. Such an underground heat exchange structure in which a spacing member is installed at a predetermined position in a resin fluid passage in a positional relationship is excellent in workability and can obtain stable underground heat exchange efficiency. Become.

  When the underground heat exchange structure is formed with the resin fluid passage of the present invention, the fluid passage may be configured in an arbitrary positional relationship as long as the fluid passage satisfies the above-described relationship. Then, when a virtual circle is drawn in plan view in the heat exchange region, the bundled fluid path and the other group of fluid paths are arranged in the vicinity of the circle in the region along the circle. Is a preferred embodiment.

  The underground heat exchanging structure comprising the resin-made fluid passage of the present invention is a method in which a structure in which the fluid passage is arranged in a predetermined position using a spacing member is prepared in advance and inserted into a hole. It may be formed.

  The underground heat exchanger using the underground heat exchange structure composed of a plurality of resin fluid paths according to the present invention is considered to require drilling with a diameter of about 25 to 30 cm with respect to the ground occupation area. When the underground heat exchange structure of the present invention is used. Since heat exchange efficiency can be increased by using a plurality of fluid paths and loss of exchange heat in the return path can be reduced, a heat exchange structure with high heat exchange efficiency as a whole is realized.

In the underground heat exchanger according to the present invention, the circulating fluid passes through the forward path toward the deep part of the ground and is taken out from the return path to the ground surface. Is preferred. This is because the temperature of the earth from the surface to a depth of about 5 m varies greatly depending on the season. In particular, it is preferable that the part of the return path has a heat insulating structure. Heat insulation of the heat medium that has finished heat exchange with the ground can be prevented by using a heat insulating structure.
Examples of a method for forming a heat insulating structure include a method of laying a heat insulating material around the pipe, and a method of providing a sheath pipe outside the pipe and filling the hollow portion with the heat insulating material.

  The circulating fluid in the resin fluid path of the present invention enters from the inlet of the fluid path and exits from the outlet through the return path, but in the summer, the underground temperature is constant and lower than the outside air temperature on the ground. The circulating fluid is cooled in the underground heat exchange region to become a circulating fluid of approximately 15 ° C., and becomes a circulating fluid warmed to the underground temperature in the underground heat exchange region in winter.

  In the underground heat exchange structure of the present invention, there are fluid path end portions serving as inlets and outlets of the circulating fluid in the fluid paths according to the number of resin fluid paths used. Each inlet fluid path end and outlet fluid path end may form a plurality of independent fluid circulation systems, or may communicate with each other to form a single fluid circulation system. When communicating to form one fluid circulation system, a plurality of inlet fluid path ends and outlet fluid path ends are connected to a single pipe using members such as a T-shaped pipe, a coupling pipe, and a header. be able to.

  Hereinafter, the present invention will be described with reference to the drawings. The specific example described below is a case where the underground heat exchange structure is formed by four resin fluid paths.

  FIG. 1 shows an example of a vertical buried underground heat exchanger 1 according to the present invention. In FIG. 1, a geothermal heat consisting of four fluid paths is formed in a borehole drilled downward from the ground surface 10 with a U-shaped pipe made of a straight resin pipe forming a forward path and a return path of the circulating fluid as a fluid path 3. The state where the exchange structure 2 is installed and backfilled with the filler 11 is shown. The U-shaped pipe composed of four straight resin pipes 3 is installed so that the resin pipes intersect each other in plan view near the lower end of the drilling hole. In the underground heat exchanging structure 2 in FIG. 1, a spacing member 5 is provided at a predetermined position.

  The drilling hole in FIG. 1 is excavated to a depth of 30 m, and the underground heat exchange structure 2 is formed by four U-shaped pipes made of polyethylene pipe having an outer diameter of 17 mm as a resin pipe and an inner diameter of 12.2 mm. Therefore, the total length of the circulating fluid path of the underground heat exchange structure 2 is 240 m.

  In the underground heat exchange structure 2 of FIG. 1, each of the forward paths of the fluid path 3 composed of four U-shaped straight resin pipe pipes communicates with each other through a header 4. Further, the return path of the fluid path is also communicated with each other by the header 4 '. The underground heat exchange structure 2 in FIG. 1 is communicated by a header to form one fluid circulation system.

  FIG. 2 is a schematic diagram showing an example of the arrangement of the fluid path of the present invention. In FIG. 2, a group of fluid paths 31 are bundled and arranged at a position almost in contact with adjacent fluid paths. In FIG. 2, four fluid paths are arranged at positions that form a quadrangular shape, and the fluid paths 32 of the other groups are arranged at intervals from adjacent fluid paths.

  The circle drawn with a broken line in FIG. 2 is a virtual circle drawn in plan view in the heat exchange region, and does not constitute the underground heat exchange structure of the present invention. Each of the bundled group of fluid paths 31 and the other group of fluid paths 32 is arranged in the vicinity of the circle. In FIG. 4, the outermost edge of the group of fluid paths 31 and the outer edges of the other groups of fluid paths 32 are arranged in contact with the circle. Such an arrangement is an example of a preferred arrangement, but the present invention is not limited to this.

  FIG. 3 is a schematic view showing another example of the fluid path arrangement of the present invention. In FIG. 3, the group of fluid paths 31 are arranged at positions that are substantially in contact with the adjacent fluid paths. The other groups of fluid paths are spaced apart from adjacent fluid paths. Also in the fluid path arrangement of FIG. 3, each fluid path is arranged in the vicinity of a circle drawn in plan view in the virtual heat exchange region. In FIG. 3 as well, the outermost edge of the group of fluid paths 31 and the other group of the outer edges of the fluid paths 32 are arranged in contact with the circle.

  In FIG. 4, the cross-sectional schematic which shows a mode that the space | interval holding member was attached to the fluid path of this invention is shown. In FIG. 4, in order to easily distinguish between the tube and the spacing member, the tube portion is displayed in gray. In FIG. 4, the fluid path that forms the underground heat exchange structure 2 is held by the tube holding portion 8 installed in the circular frame 6 of the interval holding member 5. A group of fluid paths 31 bundled from the same figure is held by one pipe holding part 8, and the pipes 32 constituting the other group of fluid paths are also held by the pipe holding part 8. Recognize.

  Although the shape of the space | interval holding member 5 is not limited to what is shown by FIG. 4, the fluid path which comprises an underground heat exchange structure is easily hold | maintained in a predetermined position with a space | interval holding member. Can do. As shown in FIG. 4, the fluid paths 31 constituting the group of fluid paths are held at a sufficient distance from the fluid paths of the other groups, so that when the group of fluid paths becomes the return path, The risk of heat being deprived from the circulating fluid that has been exchanged is reduced, which helps to increase the heat exchange efficiency of the underground heat exchange structure of the present invention.

  FIG. 5 shows the state of the fluid path at the lower end portion of the underground heat exchange structure having the fluid path arranged in the state shown in FIG. The fluid path in FIG. 5 is folded back in substantially the same depth region. From FIG. 5, it can be seen that the pipes constituting the bundled group of fluid paths communicate with the pipes constituting the other group of fluid paths, and each pipe forms a forward path and a return path of the circulating fluid.

  FIG. 6 is a schematic cross-sectional view showing another shape of the spacing member 5 that holds the fluid path. The spacing member 5 in FIG. 6 has a shape that holds the resin pipe from the inside of the fluid path. In the interval holding member 5 of FIG. 6, a tube holding portion 8 is attached to the tip of an arm 7 provided on the frame 6. Also in FIG. 6, the tube portion is displayed in gray to facilitate the distinction between the tube and the spacing member.

  FIG. 7 is a schematic view showing another arrangement example of the fluid path of the present invention. In FIG. 7, a group of fluid passages 31 constituted by eight fluid passages are bundled and arranged at a position almost in contact with adjacent fluid passages. In FIG. 7, eight fluid paths are arranged, and the other groups of fluid paths 32 are spaced from adjacent fluid paths.

  Also in FIG. 7, a group of fluid paths 31 and a fluid path 32 that are bundled are arranged in the vicinity of a virtual circle drawn by a broken line. Also in FIG. 7, the outermost edge of the group of fluid paths 31 and the outer edges of the other groups of fluid paths 32 are arranged at positions almost in contact with the circle.

  FIG. 8 is a schematic view of a heat pump system using geothermal heat having the vertical buried underground heat exchanger of the present invention as a geothermal heat exchange device. FIG. 8 shows the operation status of the ground heat heat pump system in winter. Circulating fluids such as antifreeze (brine) and water circulate in the fluid path of the underground heat exchange structure.

  In the winter season, the circulating fluid heated to the ground temperature in the ground heat heat exchange region 12 is guided to the heat exchanger A (evaporating part) 93 in the peat pump 9, and heat is taken away by heat exchange with the heat medium. As a result, the temperature drops and the heat medium evaporates due to endotherm. The circulating fluid that has been led to the heat pump 9 and whose temperature has dropped returns to the underground heat exchange region 2 again. At this time, since the underground temperature is higher in the constant temperature state than the outside air temperature on the ground, when the circulating fluid is fed into the ground from the ground side, it is collected and heated in the underground heat exchange area and circulated. It will circulate through the fluid circulation system 91 to the heat exchanger A93 in the peat pump.

The heat medium evaporated in the heat exchanger A of the peat pump enters the heat exchanger B (condensing unit) 94 through the compressor 95. A secondary heat storage medium that circulates in the heat dissipation system is guided to the heat exchanger B, and heat is released from the heat medium by heat exchange, so that the temperature of the secondary heat storage medium rises. The heat medium whose temperature has decreased due to heat dissipation circulates again to the heat exchanger A93 to exchange heat with the circulating fluid.
The secondary heat storage medium whose temperature has increased reaches the heat dissipation system 97 through the secondary heat storage medium circulation system 92, and a desired heating function is obtained. Examples of the heat dissipation system include floor heating, a fan coil unit, a snow melting panel, a snow melting heat radiation pipe, and the like. The heat dissipation system is also a circulation loop, and the secondary heat storage medium that has released heat in the heat dissipation system is again led to the heat exchanger B (refrigerant condensing unit) 94 by the secondary heat storage medium circulation system 92 and heated, It is supplied again to the heat dissipation system.
Each circulation system is provided with a pump for fluid circulation, but the display of the pump is omitted in FIG.

  In the summer, the temperature of the circulating fluid rises as the circulating fluid of approximately 15 ° C. takes heat away from the heat exchanger in the heat exchanger in the peat pump. The circulating fluid whose temperature has been increased by being guided to the heat pump returns to the underground heat heat exchange region again. At this time, since the underground temperature is constant and lower than the outside air temperature on the ground, when the circulating fluid is fed from the ground side into the ground, it is cooled in the underground heat exchange region and circulated again to the heat exchanger. It will be.

  The heat medium cooled by the circulating fluid in the peat pump enters the heat exchanger through the expansion valve and takes heat from the secondary heat storage medium. The heat medium whose temperature has risen is circulated again to the heat exchanger, and heat is taken from the circulating fluid to exchange heat with the underground heat. The cooled heat medium reaches the heat dissipation system through the pipe, and a desired cooling function is obtained. The heat dissipation system is also a circulation loop, and the secondary heat storage medium whose temperature has increased in the heat dissipation system is again guided to the heat exchanger B (refrigerant condensing unit), cooled, and supplied to the heat dissipation system again.

Vertical buried underground heat exchange that achieves high heat exchange efficiency and achieves excellent workability by the present invention, and can significantly reduce the excavation cost compared to long vertical buried underground heat exchanger A vessel is provided.
When using a vertical buried underground heat exchanger as a heat exchanger for a load device such as a heat pump, a significant percentage of the installation cost is excavation cost for installing the underground heat exchanger. Therefore, the installation cost can be greatly reduced.
The heat exchanger provided by the present invention achieves higher heat exchange efficiency and superior workability than conventionally known vertical buried underground heat exchangers.
The present invention provides a heat pump using a vertical buried underground heat exchanger that realizes high heat exchange efficiency, exhibits excellent workability, and can significantly reduce excavation costs.

1. 1. Vertical buried underground heat exchanger 2. Underground heat exchange structure Resin fluid passage 31. A bundle of bundled fluid paths 32. 3. Fluid paths constituting another group of fluid paths Header 4 '. 4. Other headers 5. Spacing member Frame 7. Arm part 8. 8. Tube holding part Heat pump 91. Circulating fluid circulation system 92.2 Secondary heat storage medium circulation system 93. Heat exchanger A
94. Heat exchanger B
95. Compressor 96. Expansion valve 97. Heat dissipation system 10. Surface 11. Filler 12. Underground heat exchange a. Circulating fluid inlet b. Circulating fluid outlet

Claims (9)

  In the heat exchange area formed vertically below the ground surface, as a fluid path for exchanging the circulating fluid to the ground, the forward path for flowing the circulating fluid from the ground side toward the ground and the fluid that has passed through the forward path are A plurality of resin fluid paths having return paths that flow from the surface toward the ground surface, a group of fluid paths are bundled so as to be in close contact with adjacent fluid paths, and the other groups of fluid paths are adjacent to each other. Ground heat exchange provided with a ground heat exchange structure that is arranged with a gap between the path and the group of fluid paths and the other group of fluid paths form an outward path or a return path, respectively. vessel.   The underground heat exchanger according to claim 1, wherein the bundled fluid path is a return path.   3. The underground heat exchange according to claim 1, wherein the other group of fluid paths maintain an interval of at least 6 cm as an interval between pipe centers between adjacent fluid paths. vessel.   The number of the resin-made fluid paths which form the said underground heat exchange structure is 3-8, The underground heat exchanger in any one of Claims 1-3 characterized by the above-mentioned.   The underground heat exchanger according to any one of claims 1 to 4, wherein a contact point between each forward path and the return path of the resin-made fluid path is in a region having substantially the same depth.   The underground heat exchanger according to any one of claims 1 to 5, wherein the resin fluid path is a U-shaped pipe made of a straight resin pipe.   When a circle is drawn in plan view in the heat exchange region at a position in the middle in the vertical direction of the fluid path, the bundled fluid path and the other group of fluid paths are arranged in the vicinity of the circle. The underground heat exchanger according to any one of claims 1 to 6.   The underground heat exchanger according to any one of claims 1 to 7, wherein the underground heat exchange structure includes an interval holding member that holds an interval between the fluid paths at a predetermined interval.   A ground heat utilization heat pump system having the underground heat exchanger according to any one of claims 1 to 8 as a heat exchange device.