JP2010156468A - Underground heat exchanger and air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize decline in heat exchange capacity even when a crack is generated on an outer wall for any cause and carbon dioxide present inside is leaked into the ground, in an underground heat exchanger for performing heat exchange between a refrigerant and underground soil via the sealed carbon dioxide. <P>SOLUTION: A body (1a) of the underground heat exchanger is formed by axially juxtaposing a plurality of outer cylinders (3) each having a sealed space (7) filled with carbon dioxide and formed inside. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a ground heat exchanger for exchanging heat between a heat exchange fluid and soil in the ground, and an air conditioning system using the same.

  2. Description of the Related Art Conventionally, underground heat exchangers that exchange heat between a heat exchange fluid and underground soil via a sealed heat medium are known. This underground heat exchanger is used in, for example, a refrigerant circuit that performs a refrigeration cycle. Patent Document 1 discloses a geothermal heat exchanger that heats the refrigerant (heat exchange fluid) of the refrigerant circuit using geothermal heat in heating operation.

  The underground heat exchanger of patent document 1 is comprised with the double tube | pipe type heat exchanger which consists of an outer tube (outer cylinder part) and the inner tube inserted inside this outer tube. The inner tube is closed at both ends to form a sealed space inside. The heat medium is sealed in the sealed space. The outer pipe has a refrigerant passage through which the refrigerant of the refrigerant circuit flows.

  The inner pipe is fixed to the inner side of the outer pipe so that the upper and lower ends protrude from the inner side of the outer pipe in the pipe axis direction. The inner pipe protruding downward from the outer pipe is buried in the ground so that the pipe axis direction of the inner pipe is along the vertical direction. That is, the lower part of the inner pipe is in contact with the soil in the ground, and the upper part of the inner pipe is in contact with the refrigerant flowing through the refrigerant passage of the outer pipe.

In such a configuration, when a refrigerant having a temperature lower than that in the ground is caused to flow through the refrigerant flow path, the heat medium vapor having the equilibrium vapor pressure at the underground temperature and the refrigerant path of the outer pipe are disposed above the inner pipe. The cooling medium flowing through the heat exchanger exchanges heat to condense the heat medium, and the refrigerant is heated by the heat of condensation. The cold heat medium condensed and liquefied descends from the upper side to the lower side in the inner tube. At the lower end side of the inner pipe, the soil in the ground and the heat medium exchange heat, and the heat medium is evaporated so as to have a vapor pressure balanced with the temperature in the ground. The evaporated heat medium rises again in the inner tube from the lower end side toward the upper end side. That is, the inner pipe becomes a heat pipe, and the refrigerant in the refrigerant pipe can be heated by underground heat.
International Publication No. WO2004 / 111559 Pamphlet

  However, in the conventional underground heat exchanger like this patent document 1, when a crack is generated in a pipe buried in the ground due to a natural disaster or the like, it is considered that the heat medium leaks from the cracked portion. If it becomes like this, the quantity of the heat medium in the said sealed space will reduce, and the heat exchange capability of an underground heat exchanger will fall.

  The present invention has been made in view of such a point, and an object of the present invention is to provide any cause in the underground heat exchanger that exchanges heat between the heat exchange fluid and the soil in the ground via a sealed heat medium. Thus, even if the heat medium in the pipe leaks to the outside of the pipe, it is possible to minimize a decrease in heat exchange capacity.

  1st invention has the main-body part (1a) in which the fluid flow path (6) through which a heat exchange fluid flows, and the sealed space (7) which sealed the heat medium were formed, The said main-body part (1a) It is premised on an underground heat exchanger that performs heat exchange between the heat exchange fluid and the soil in the ground through the heat medium by being embedded in the ground.

  And the main-body part (1a) of the said underground heat exchanger has a some outer cylinder part (3), and the inner pipe (2) inserted inside this some outer cylinder part (3). The fluid flow path (6) is formed inside the inner pipe (2), and the inner cylinder (3) has an inner pipe (2) on the inner pipe (2). The sealed space (7) is formed so as to surround an insertion portion inserted inside.

In the first invention, a plurality of sealed spaces (7) are formed in the main body (1a) by forming a plurality of outer tube portions (3). In this way, even if a certain outer cylinder part (3) cracks due to a natural disaster, etc., the heat medium only leaks into the ground from the sealed space (7) of the outer cylinder part (3) where the crack has occurred. The heat medium can be prevented from leaking into the ground from the sealed space (7) of the other outer cylinder part (3). In the second invention, the plurality of outer cylinder parts (3 ) Is arranged in parallel, in series, or in series-parallel. Here, the arrangement of the plurality of outer cylinder portions (3) in series-parallel means that the outer cylinder portions (3) are arranged in the series direction and the parallel direction, respectively.

  In the second invention, the plurality of outer tube portions (3) are arranged in parallel, so that the plurality of outer tube portions (3) are deeper than the case where they are arranged in series. There is no need to dig a hole. On the contrary, by arranging the plurality of outer cylinder portions (3) in series, the arrangement area is reduced as compared with the case where they are arranged in parallel.

  Also, by arranging the plurality of outer cylinder parts (3) in series-parallel, the plurality of outer cylinder parts (3) can be grounded compared to the case where all the outer cylinder parts (3) are arranged in series. It is not necessary to dig deeply to fill the inside, and the arrangement area is smaller than when all the outer cylinder portions (3) are arranged in parallel.

  According to a third invention, in the second invention, the inner tube (2) includes an outer tube portion (3) adjacent in the series direction among the plurality of outer tube portions (3) arranged in series or in series and parallel. ) And the outer tube portion (3), each of the outer tube portions (3) is divided into a plurality of divided tubes (2a), and the adjacent divided tubes (2a) and the divided tubes (2a) A series inner pipe connecting member (9) for connecting the divided pipes (2a) to each other is provided between them.

  In 3rd invention, the inner pipe | tube (2) inserted inside a some outer cylinder part (3) is divided | segmented for every outer cylinder part (3). A dividing pipe (2a) formed by dividing the inner pipe (2) is inserted into each outer cylinder (3). Adjacent divided pipes (2a) are connected to each other by a series inner pipe connecting member (9).

  In a fourth aspect based on the third aspect, the main body (1a) has a plurality of divided portions (23) divided in the series direction, and the divided portions (23) are formed by the outer cylinders. It is characterized by comprising a part (3) and the above-mentioned divided pipe (2a) inserted and fixed to each outer cylinder part (3).

  In 4th invention, the said inner pipe (2) is divided | segmented for every said outer cylinder part (3), and the division | segmentation pipe | tube (2a) of the inner pipe | tube (2) is the outer cylinder part corresponding to this division pipe | tube (2a). What is fixed to (3) can be configured as the dividing section (23).

  5th invention is the 3rd or 4th invention. Outer cylinder part (3) and outer cylinder part which adjoin in the serial direction among several outer cylinder parts (3) arrange | positioned in series or series-parallel (3) are arranged in a space in the axial direction, and in the space, the outer cylinder portions (3) are connected to each other so as to surround the serial inner pipe connecting member (9). A connecting member (20) for the cylinder portion is provided.

  In 5th invention, the connection part (23) adjacent to a serial direction can be reliably connected by providing the connection member (20) for the said outer cylinder parts. Further, since the connecting member (20) for the outer cylinder portion is disposed so as to surround the inner pipe connecting member (9) for series connection, the inner pipe connecting member (9) for series connection is protected. Can do.

  In a sixth aspect based on the fifth aspect, the connecting member (20) for the outer cylinder part is formed with an opening (16) at a position facing the in-line inner pipe connecting member (9). It is characterized by having.

  In 6th invention, the operation | work of the said inner pipe connection member (9) for series through the said opening part (16) can perform the connection operation | work of the division pipes (2a) adjacent to a series direction.

  According to a seventh aspect, in the second aspect, among the plurality of outer tube portions (3) disposed in parallel or in series, the inner portions corresponding to the outer tube portions (3) disposed in the parallel direction. It is characterized by comprising an inner pipe connecting member (17) for parallel connection between the pipes (2).

  In the seventh invention, the inner pipes (2) corresponding to the outer cylinder parts (3) arranged in the parallel direction can be connected to each other by the parallel inner pipe connecting member (17). become.

  According to an eighth invention, in any one of the first to seventh inventions, the outer tube portion (3) and the inner tube (2) are connected to the inner peripheral surface (21) of the outer tube portion (3). The outer pipe (22) of the inner pipe (2) is arranged so as to be substantially in contact with each other.

  Here, after the underground heat exchanger according to the present invention is embedded, when the heat exchange fluid having a temperature lower than the soil in the ground is passed through the fluid flow path (6) of the inner pipe (2), the outer cylinder The heat medium sealed in the part (3) releases heat to the heat exchange fluid having a temperature lower than that of the heat medium through the outer peripheral surface (22) of the inner pipe (2) and condenses. At this time, the heat exchange fluid is heated by absorbing the heat of condensation of the heat medium.

  The heat medium condensed and liquefied on the outer peripheral surface (22) of the inner pipe (2) passes through the inner peripheral surface (21) of the outer cylinder (3) and has a higher temperature than the heat medium. It absorbs heat from the soil and evaporates. The heat medium evaporated and vaporized on the inner peripheral surface (21) of the outer tube portion (3) is condensed again on the outer peripheral surface (22) of the inner tube (2). Thus, when the heat medium repeats condensation and evaporation, the heat of the soil in the ground is transmitted to the heat exchange fluid via the heat medium, and the heat exchange fluid is heated.

  Conversely, if a heat exchange fluid having a temperature higher than that of the soil in the ground flows through the fluid flow path (6) of the inner pipe (2), the heat medium is transferred to the inner cylinder (3). It condenses on the peripheral surface (21) and evaporates on the outer peripheral surface (22) of the inner pipe (2). Thereby, the heat of the heat exchange fluid is transmitted to the soil in the ground via the heat medium, and the heat exchange fluid is cooled.

  In the eighth aspect of the invention, the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2) are substantially brought into contact with each other via this contact portion. The heat medium condensed and liquefied on one surface of the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2) flows to the other surface. Here, the substantially contacted state means that the outer tube part (3) and the inner tube (2) are in direct contact with each other indirectly via a liquefied heat medium. In contact with each other.

  According to a ninth invention, in the eighth invention, the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2) are circumferentially arranged along the circumferential direction. A groove (30, 31) is formed.

  In the ninth invention, the heat medium condensed and liquefied on one surface of the outer tube portion (3) and the inner tube (2) is a circumferential groove (30, 31) formed on one surface thereof. It flows in the circumferential direction along the circumferential groove (30). This heat medium flows to the other surface through the contact portion of the outer tube portion (3) and the inner tube (2). The heat medium that has flowed to the other surface flows and evaporates along the circumferential groove (30) while being held in the circumferential grooves (30, 31) formed on the other surface. become. The circumferential groove (30, 31) may be formed in a spiral shape.

  According to a tenth aspect of the present invention, in any one of the first to ninth aspects, one surface of the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2). A liquid transport member (8) for transporting the heat medium liquefied in step (1) to the other surface is provided.

  In the tenth aspect of the invention, the liquid liquefied on one surface of the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2) by the liquid transport member (8). The medium can be actively conveyed to the other surface and evaporated.

  In an eleventh aspect based on the tenth aspect, the liquid transport member (8) is a wick, and the wick includes the inner peripheral surface (21) of the outer tube portion (3) and the inner pipe (2). It is provided so that it may contact both of an outer peripheral surface (22). Here, the wick is a porous body having a large number of fine pores formed therein, and a capillary passage is formed by the continuous fine pores. And a liquid flows through this capillary channel by capillary action. The porous body may be formed by sintering metal or ceramic powder, or may be formed by overlapping mesh-like metals or bundling metal fibers.

  In an eleventh aspect of the invention, the liquid conveying member (8) is constituted by a wick, so that the liquefied heat medium condensed on one surface of the outer tube portion (3) and the inner tube (2) is contained in the wick. It becomes possible to positively convey and evaporate the other surface by the capillary phenomenon.

  A twelfth invention is characterized in that, in any one of the first to eleventh inventions, the heat medium enclosed in the sealed space (7) of the outer tube portion (3) is carbon dioxide.

  In the twelfth invention, even if a crack occurs in the outer cylinder part (3) for some reason and the heat medium leaks into the ground from the crack part, the heat medium is composed of carbon dioxide. The soil and groundwater can be prevented from polluting.

  A thirteenth invention is characterized in that, in any one of the first to eleventh inventions, the heat medium enclosed in the sealed space (7) of the outer cylinder portion (3) is water.

  In the thirteenth invention, even if a crack occurs in the outer cylindrical portion (3) for some reason and the heat medium leaks into the ground from the cracked portion, the soil or groundwater in the ground is the same as in the fifth invention. Can be prevented from polluting. In addition, since water has a larger latent heat than carbon dioxide, the amount of water sealed in the outer cylinder portion (3) can be reduced.

  A fourteenth invention is characterized in that, in any one of the first to eleventh inventions, the heat medium sealed in the sealed space (7) of the outer tube portion (3) is ammonia.

  In the fourteenth invention, it is possible to reduce the thickness of the outer cylindrical portion (3) by utilizing the fact that the working pressure range of ammonia is lower than that of carbon dioxide. In addition, since ammonia has a larger latent heat of vaporization than carbon dioxide, the amount of ammonia sealed in the outer cylinder (3) can be reduced in the same manner as water.

  According to a fifteenth aspect, in any one of the first to fourteenth aspects, at least one of the plurality of outer tube portions (3) has a different axial length from the other outer tube portions (3). It is configured as described above.

  In the fifteenth aspect of the invention, the underground heat exchanger is configured by combining outer cylinder portions (3) having different axial lengths. For example, when comparing between outer cylinder parts (3) with different lengths, the outer cylinder part (3) with a shorter length has a smaller heat transfer area than the outer cylinder part (3) with a longer length. Small heat exchange capacity. Therefore, the above-mentioned underground heat exchanger can be assembled by combining the outer cylinder portions (3) having different lengths so as to obtain a desired heat exchange capability.

  The sixteenth invention is characterized in that, in any one of the first to fourteenth inventions, the plurality of outer tube portions (3) are all equal in length in the axial direction.

  In the sixteenth invention, a plurality of outer cylinder parts (3) having the same length are manufactured, and the outer cylinder parts (3) are arranged to form a ground heat exchanger.

  A seventeenth invention is a refrigerant circuit in which a compressor (14), a heat source side heat exchanger (1), an expansion mechanism (12), and a use side heat exchanger (11) are connected to perform a vapor compression refrigeration cycle. It assumes an air conditioning system with (10).

  And in the said air conditioning system, the inner pipe (2) of the underground heat exchanger as described in any one of 1st to 16th invention is connected to the said refrigerant circuit (10), The said heat source side heat exchange The furnace (1) constitutes the above ground heat exchanger.

  In the seventeenth aspect of the invention, in the air conditioning system, a ground heat exchanger can be used as the heat source side heat exchanger (1) in the vapor compression refrigeration cycle. When the air conditioning system is a heating device, the underground heat exchanger serves as an evaporator, and the use side heat exchanger (11) serves as a condenser. In this underground heat exchanger, the low-pressure refrigerant that has flowed out of the expansion mechanism (12) exchanges heat with the soil in the ground, and the low-pressure refrigerant absorbs heat from the soil in the ground. Can be evaporated.

  On the other hand, when the air conditioning system is a cooling device, the underground heat exchanger serves as a condenser, and the use side heat exchanger (11) serves as an evaporator. In the underground heat exchanger, the high-pressure refrigerant discharged from the compressor (14) exchanges heat with the soil in the ground, and the high-pressure refrigerant dissipates heat to the soil in the ground. Can be condensed.

  According to the present invention, even if a crack occurs in the outer cylinder part (3) due to a natural disaster or the like in the main body part (1a), the sealed space (7) of the outer cylinder part (3) in which the crack has occurred. ) Only leaks into the ground, and does not leak from the enclosed space (7) of the other outer cylinder (3). Thereby, the quantity of the heat medium leaking outside from the main body part (1a) can be reduced as compared with the prior art, and the decrease in the heat exchange capability of the underground heat exchanger can be minimized.

  According to the second aspect of the present invention, by arranging the plurality of outer tube portions (3) in parallel, the depth of the hole for filling the plurality of outer tube portions (3) in the ground is shortened. In addition, by arranging the plurality of outer cylinder portions (3) in series, the arrangement area of the plurality of outer cylinder portions (3) can be reduced.

  According to the third aspect of the present invention, the divided pipe (2a) formed by dividing the inner pipe (2) is inserted into each outer cylinder portion (3). And the underground heat exchanger which consists of a some outer cylinder part (3) is formed by connecting adjacent division pipes (2a) with the internal pipe connection member (9) for series. If it carries out like this, compared with the case where a some outer cylinder part (3) is inserted in the outer side of an inner pipe (2), it can make it easy to manufacture the said underground heat exchanger.

  According to the fourth aspect of the present invention, the split tube (2a) fixed to the outer tube portion (3) can be configured as the split portion (23). If comprised in this way, manufacture of the said underground heat exchanger can be performed easily compared with the case where the said main-body part (1a) is not divided | segmented. In addition, when dividing | segmenting a main-body part (1a), it is good to divide | segment the said main-body part (1a) into the length which is easy to manufacture.

  Moreover, according to the said 5th invention, while the said division member (20) for outer cylinder parts can connect adjacent division | segmentation parts (23) reliably, the said inner pipe connection member for series (9) can be protected. Thereby, the quality of the said underground heat exchanger can be improved.

  Further, according to the sixth invention, by operating the connecting member (9) for the inner pipe from the opening (16), it is possible to perform the connecting work between the adjacent divided pipes (2a), The efficiency of the connection work of the underground heat exchanger can be improved.

  Further, according to the seventh invention, the inner pipes (2) corresponding to the outer cylinder portions (3) arranged in the parallel direction are connected to each other by the parallel inner pipe connecting member (17). be able to.

  According to the eighth aspect of the invention, by bringing the outer cylinder part (3) and the inner pipe (2) into contact, the inner peripheral surface (21) of the outer cylinder part (3) and the inner pipe The heat medium condensed and liquefied on one surface of the outer peripheral surface (22) of (2) can be reliably guided to the other surface and evaporated on the other surface. Thereby, the heat exchange capability of the underground heat exchanger can be improved.

  According to the ninth aspect of the present invention, the heat medium condensed and liquefied on one surface of the outer tube portion (3) and the inner tube (2) is a circumferential groove formed on one surface thereof. (30, 31) is guided to the other surface while being held so as not to fall downward, and the entire groove is held so as not to fall downward by a circumferential groove (30, 31) formed on the other side. Evaporates while spreading.

  In this way, the liquefied heat medium can be guided from one surface to the other surface while holding the liquefied heat medium so as not to fall downward in the circumferential groove (30, 31), and the circumferential groove Compared with the case where (30, 31) is not provided, a larger amount of the heat medium is guided to the other surface. Thereby, the heat exchange capability of the underground heat exchanger can be further improved.

  According to the tenth aspect of the invention, the heat medium condensed and liquefied on one surface of the outer tube portion (3) and the inner tube (2) using the liquid transport member (8). It can be positively conveyed to the other surface. Thereby, the heat exchange efficiency of the said underground heat exchanger can be improved further.

  Further, according to the eleventh aspect of the invention, by utilizing a wick as the liquid transport member (8), it is possible to transport the heat medium while reducing the cost of the liquid transport member (8). It is possible to achieve both high efficiency and low cost of the underground heat exchanger.

  Further, according to the twelfth and thirteenth inventions, even if a crack occurs in the outer cylindrical portion (3) for some reason and the heat medium leaks into the ground from the crack portion, the heat medium is carbon dioxide. It does not contaminate the soil and groundwater in the ground. Therefore, it is possible to provide an underground heat exchanger that takes into consideration the global environment.

  Further, according to the fourteenth aspect, by using ammonia as the heat medium, the amount of heat exchange of the heat medium with respect to the heat exchange fluid and the soil in the ground can be increased as compared with the case where carbon dioxide is used. it can. Thereby, the heat exchange capability of the underground heat exchanger can be improved.

  According to the fifteenth aspect of the invention, when the underground heat exchanger is assembled, the outer cylinder portions (3) having different lengths can be combined so as to have a desired heat exchange capability. Thereby, the underground heat exchanger which has the optimal heat exchange capability can be provided.

  According to the sixteenth aspect of the present invention, a ground heat exchanger can be formed by manufacturing a plurality of outer tube portions (3) having the same length and arranging the outer tube portions (3). Thereby, since it is not necessary to manufacture the outer cylinder part (3) of various lengths, the manufacturing cost of an outer cylinder part (3) can be reduced.

  According to the seventeenth aspect of the invention, in the air conditioning system, a crack is generated in the outer cylinder part (3) of the underground heat exchanger, and heat is generated from the sealed space (7) of the outer cylinder part (3). Even if the medium leaks into the ground, the heat medium does not leak from the other outer cylinder (3), so it is possible to minimize the deterioration of the heat exchange capacity of the underground heat exchanger. . Therefore, it is possible to minimize a decrease in the capacity of the air conditioning system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1
The heating device according to the first embodiment heats a room using underground heat and constitutes an air conditioning system according to the present invention.

<Configuration of heating system>
The said heating apparatus is provided with the refrigerant circuit (10), as shown in FIG. The refrigerant circuit (10) includes a compressor (14), an indoor heat exchanger (use side heat exchanger) (11), an expansion valve (expansion mechanism) (12), and an underground heat exchanger (heat source side heat exchanger). ) And (1) are connected by refrigerant piping. Here, the underground heat exchanger (1) is buried in the ground, and the indoor heat exchanger (11) is installed indoors. In addition, when there is a machine room in the basement, the machine room includes element devices other than the indoor heat exchanger (11) and the underground heat exchanger (1) in the heating device, that is, the compressor (14) and the expansion. A valve (12) etc. may be installed.

  A refrigerant (heat exchange fluid) is enclosed in the refrigerant circuit (10). As this refrigerant circulates in the refrigerant circuit (10), the underground heat exchanger (1) becomes an evaporator, the indoor heat exchanger (11) becomes a condenser, and a vapor compression refrigeration cycle is established. Configured to do.

  The underground heat exchanger (1) exchanges heat between the soil in the ground and the refrigerant flowing through the refrigerant circuit via carbon dioxide (heat medium) sealed inside. Details of the underground heat exchanger (1) will be described later. The compressor (14) is a hermetically sealed type, and has a variable capacity by an inverter (not shown) electrically connected to the compressor (14). The compressor (14) is configured to compress the sucked refrigerant to a predetermined pressure and discharge it.

  Although not shown in the drawings, the indoor heat exchanger (11) is a cross-fin type fin-and-and-tube in which heat transfer tubes are arranged in a plurality of paths and a number of aluminum fins are arranged orthogonal to the heat transfer tubes.・ It consists of a tube heat exchanger. An indoor fan (13) is installed in the vicinity of the indoor heat exchanger (11). Then, the refrigerant flows inside the heat transfer tube, the indoor air sent from the indoor fan (13) flows between the aluminum fins outside the heat transfer tube, and both perform heat exchange. Yes. The expansion valve (12) is an electronic expansion valve having a variable opening. The degree of decompression of the refrigerant flowing through the expansion valve (12) is adjusted by changing the opening degree of the expansion valve (12).

<Configuration of underground heat exchanger>
As shown in FIG. 1, the underground heat exchanger (1) has a main body (1a) formed by connecting a plurality of divided units (divided portions) (23) in series in the tube axis direction. is doing. The underground heat exchanger (1) is buried in the ground so that the main body (1a) tube axis direction is along the vertical direction.

  Each of the split units (23) has an outer tube portion (3) and a split tube (2a), and the split tube (2a) is inserted and fixed inside the tube of the outer tube portion (3). A tubular heat exchanger is constructed. Note that the lengths of the divided units (23) are all the same.

  The outer cylinder (3) has an upper closing plate (4) attached to its upper end and a lower closing plate (5) attached to its lower end. Note that two through holes are provided in each of the upper closing plate (4) and the lower closing plate (5) of each divided unit (23) except for the lowermost divided unit (23). The lowermost division unit (23) is provided with two through holes only in the upper closing plate (4). And by sealing each said outer cylinder part (3) with both obstruction | occlusion board (4,5), the sealed space (7) is formed in the inner side. A predetermined amount of carbon dioxide is sealed in the sealed space (7). In addition, since the temperature when the refrigerant of the refrigerant circuit (9) flows into the underground heat exchanger (1) is approximately between -10 ° C and 40 ° C, carbon dioxide is reduced from -10 ° C to 40 ° C. It is enclosed so as to change phase between degrees Celsius.

  In addition, in the outer cylinder part (3) of each divided unit (23) excluding the uppermost and lowermost divided units (23), the outer cylinder part (3) is axially extended from both closing plates (4, 5). A cylindrical wall (20) having the same diameter as that extends. This cylinder wall (20) constitutes the connecting member for the outer cylinder part. As shown in FIG. 5, the cylindrical wall (20) is provided with an opening (16) for touching a union (9) described later. Although not shown, a side plate for closing the opening (16) is provided. The side plate can protect the union (9).

  An insertion part for connecting adjacent outer cylinder parts (3) is formed at the tip of the cylinder wall (20).

  The uppermost split unit (23) has a cylindrical wall (20) having the same diameter as that of the outer cylindrical portion (3) extending from the lower closing plate (5) in the axial direction. The part is formed. In the case of the lowermost division unit (23), a cylindrical wall (20) having the same diameter as that of the outer cylindrical portion (3) extends in the axial direction from the upper closing plate (4), and the above-mentioned plug is inserted at the tip thereof. The part is formed.

  Further, in the outer cylindrical portion (3) of each of the divided units (23), the inner wall surface (inner peripheral surface) (21) facing the sealed space (7) has a circumferential direction as shown in FIG. A plurality of circumferential grooves (30) are formed so as to be along.

  There are two types of the dividing pipe (2a): one formed in a straight tube shape and one formed in a U-shape. These divided pipes (2a) are connected to each other to form an inner pipe (2). As shown in FIG. 2, the split pipe (2a) has its outer wall surface (22) in contact with the inner wall surface (21) facing the sealed space (7) in the outer cylinder portion (3). It is fixed to the outer cylinder part (3). That is, the outer wall surface (22) of the inner tube (2) formed by connecting the split tube (2a) is in contact with the inner wall surface (21) facing the sealed space (7) in the outer tube portion (3). is doing. A large number of circumferential grooves (31) of about 100 microns are formed on the outer wall surface (22) of the dividing pipe (2a). The shape of the circumferential groove (31) is merely an example.

  Each of the split units (23) except the lowermost split unit (23) includes the two straight pipe-shaped split pipes (2a) so that the pipe end portion protrudes from the sealed space (7). The upper closing plate (4) and the lower closing plate (5) are inserted and fixed in the through holes. On the other hand, in the lowermost division unit (23), the U-shaped division pipe (2a) passes through each of the upper closing plates (4) so that the pipe end portion protrudes from the sealed space (7). It is inserted and fixed in the hole.

  Moreover, the union (9) for connecting the division pipes (2a) is provided in the pipe end part of the adjacent division pipes (2a). The union (9) constitutes a connecting member (9) for an inner pipe that connects the divided pipes (2a) to each other outside the sealed space (7). And these division pipes (2a) are connected with a union (9), and constitute an inner pipe (2).

  One end of the inner pipe (2) is connected to a refrigerant pipe extending from the discharge side of the compressor (14), and the other end is connected to a refrigerant pipe extending from the inlet side of the expansion valve (12). By being connected in this way, a refrigerant passage (fluid flow path) (6) through which the refrigerant of the refrigerant circuit (10) flows is formed inside the inner pipe (2).

-Driving action-
Next, operation | movement of the said heating apparatus is demonstrated.

  The high-pressure refrigerant discharged after being compressed to a predetermined pressure by the compressor (14) flows into the indoor heat exchanger (11). In the indoor heat exchanger (11), the high-pressure refrigerant releases heat from the indoor air sent from the indoor fan (13) and condenses, and then flows out from the indoor heat exchanger (11). On the other hand, the indoor air is warmed by this condensation heat. As a result, the room is heated. The high-pressure refrigerant that has flowed out of the indoor heat exchanger (11) flows into the expansion valve (12). In the expansion valve (12), after the high-pressure refrigerant is depressurized to a predetermined pressure to become a low-pressure refrigerant, the expansion valve (12) flows out. At this time, the low-pressure refrigerant is decompressed by the expansion valve (12) so that the saturation temperature of the decompressed low-pressure refrigerant is lower than the temperature of the soil in the ground.

  The low-pressure refrigerant that has flowed out of the expansion valve (12) flows into the underground heat exchanger (1). In the underground heat exchanger (1), the low-pressure refrigerant absorbs the underground heat and evaporates, and then flows out of the underground heat exchanger (1). The low-pressure refrigerant that has flowed out of the underground heat exchanger (1) is sucked into the compressor (14), compressed to a predetermined pressure, and then flows into the indoor heat exchanger (11) again. In this way, the refrigerant circulates in the refrigerant circuit (10), thereby heating the room.

  Next, the operation of the underground heat exchanger (1) will be described.

  The low-pressure refrigerant that has flowed out of the expansion valve (12) flows in from the split pipe (2a) of the uppermost split unit (23) in the underground heat exchanger (1). The low-pressure refrigerant that has flowed into the split pipe (2a) flows downward toward the lowermost split unit (23), and after making a U-turn in the lowermost split unit (23), the uppermost split unit ( 23) flows upward and flows out of the uppermost split unit (23). When a low-pressure refrigerant having a temperature lower than the temperature of the soil in the ground flows into the dividing pipe (2a), the saturation temperature of carbon dioxide in each sealed space (7) is between the soil and the low-pressure refrigerant. It shall be temperature.

  In this case, as shown in FIG. 4, the carbon dioxide is condensed on the outer wall surface (outer peripheral surface) (22) of the dividing pipe (2a) having a temperature lower than the saturation temperature of the carbon dioxide. The refrigerant of the refrigerant circuit (9) absorbs the heat of condensation of carbon dioxide and evaporates. The evaporated refrigerant flows out of the underground heat exchanger (1) and is then sucked into the compressor (14).

  The carbon dioxide condensed and liquefied on the outer wall surface (22) is held by the circumferential groove (31) of the outer wall surface (22) without falling down, and is circled along the circumferential groove (31). It flows to spread in the circumferential direction. And this liquefied carbon dioxide is guide | induced to the inner wall face (21) of the said outer cylinder part (3) through the contact part of the said outer cylinder part (3) and the said division pipe (2a). The carbon dioxide guided to the inner wall surface (21) of the outer cylinder part (3) is held by the circumferential groove (30) of the outer cylinder part (3) without falling down, while the circumferential groove (30) It flows so as to spread in the circumferential direction along. Carbon dioxide evaporates on the inner wall surface (21). Carbon dioxide evaporated and gasified on the inner wall surface (21) moves toward the outer wall surface (22) of the divided pipe (2a) due to the density difference of carbon dioxide in the divided space (7a), It condenses again on its outer wall (22). As carbon dioxide repeats the phase change in this way, the soil in the ground outside the outer cylinder part (3) and the refrigerant flowing inside the dividing pipe (2a) are heated by the carbon dioxide. Exchange.

-Effect of Embodiment 1-
According to the first embodiment, a plurality of sealed spaces (7) can be formed in the main body (1a) by arranging a plurality of outer cylinders (3) in the axial direction. In this way, even if a certain outer cylinder part (3) cracks due to a natural disaster, etc., only carbon dioxide leaks into the ground from the sealed space (7) of the outer cylinder part (3) where the crack occurred. Carbon dioxide does not leak from the sealed space (7) of the other outer cylinder (3). Thereby, the quantity of the carbon dioxide which leaks outside from the said outer cylinder part (3) can be decreased, and the fall of the heat exchange capability of a ground heat exchanger can be suppressed to the minimum.

  In addition, by changing the number of the plurality of outer tube portions (3), an underground heat exchanger having an arbitrary length can be easily installed on site.

  Further, the inner pipe (2) through which the refrigerant of the refrigerant circuit (10) flows is located in the ground and protected by the strength unit by the dividing unit (23) and the cylindrical wall (20) (directly touching the soil). Therefore, soil and groundwater contamination due to leakage of refrigerant in the refrigerant circuit (10) from the inner pipe (2) can be avoided.

  Further, according to the first embodiment, the inner pipe (2) is divided into the outer cylinder parts (3), and the dividing pipe (2a) of the inner pipe (2) corresponds to the dividing pipe (2a). What was fixed to the outer cylinder part (3) to perform can be comprised as the said division | segmentation part (23). If comprised in this way, manufacture of the said underground heat exchanger can be performed easily compared with the case where the said main-body part (1a) is not divided | segmented. In this case, the main body (1a) may be divided into lengths that are easy to produce in the factory, easy to carry into the burial site, and do not deteriorate in performance.

  The division unit (23) can be manufactured in a factory, and the productivity and quality of the division unit (23) can be managed. In addition, an underground heat exchanger of any length can be easily installed on site, and the length in the vertical direction can be divided into short sections (the distance traveled by the heat medium sealed inside can be managed). The heat exchange performance is kept constant.

  For example, when the underground heat exchanger is embedded in the ground, the main body (1a) can be embedded unless the main body (1a) is once erected in the tube axis direction. Can not. According to the first embodiment, for example, by dividing the main body portion (1a) into a length that makes it easy to stand up, the stand-up operation of the divided portion (23) is facilitated, and the underground heat exchanger is buried. Work efficiency can be improved.

  Further, according to the first embodiment, the union (9) can be protected by the cylindrical wall (20) extending in the axial direction from the closing plate (4, 5) of the outer cylindrical portion (3), and Adjacent division parts (23) can be reliably connected by the insertion part formed in the front-end | tip of the said cylinder wall (20). Thereby, the quality of the said underground heat exchanger can be improved.

  In addition, according to the first embodiment, by connecting the union (9) through the opening (16), it is possible to connect the adjacent divided pipes (2a) to each other, and the underground heat exchanger The efficiency of the connecting work can be improved.

  Further, according to the first embodiment, the outer cylinder portion (3) and the dividing pipe (2a) are brought into contact with each other to condense and liquefy the dioxide dioxide on the outer wall surface (22) of the dividing pipe (2a). Carbon can be reliably guided to the inner wall surface (21) of the outer cylinder part (3). In addition, since circumferential grooves (30, 31) are formed on the inner wall surface (21) of the outer tube portion (3) and the outer wall surface (22) of the inner tube (2), respectively, liquefied carbon dioxide Can be guided and evaporated more to the inner wall surface (21) of the outer cylinder part (3) while being held by the circumferential groove (30, 31) so as not to fall downward. Thereby, the heat exchange capability of the underground heat exchanger (1) can be improved.

  Further, according to the first embodiment, even if a crack occurs in the outer cylinder part (3) for some reason, and the heat medium leaks from the crack part into the ground, the heat medium is carbon dioxide. There is no pollution inside. The inner pipe (2) is isolated from the soil inside the underground heat exchanger. Thereby, it can avoid that a refrigerant | coolant leaks and contaminates soil and groundwater resulting from deterioration, such as corrosion of the said inner pipe | tube (2). From this, it is possible to provide an underground heat exchanger in consideration of the global environment.

-Modification 1 of Embodiment 1-
In the underground heat exchanger of the first embodiment, the shape in the vicinity of the union (9) in the split pipe (2a) of the main body (1a) is formed in a straight pipe shape. As shown, the shape of the dividing pipe (2a) in the vicinity of the union (9) is formed in a curved tube shape.

  In addition, the union (2a) can be easily inserted into the outer cylindrical portions (3) through the through holes of both the blocking plates (4, 5). Elbow joints (9a) are provided at both ends of 9).

  When the split pipe (2a) is formed in a curved shape in this way, the union (9) can be turned sideways, and the distance between the adjacent sealed spaces (7) can be shortened. Since the sealed space (7) can be lengthened as the distance is shortened, the performance of the underground heat exchanger can be improved. In addition, by turning the union (9) sideways, even if a vertical compression or expansion force is applied to the underground heat exchanger due to an earthquake or the like, the force is not directly applied to the union (9). Can be avoided.

-Modification 2 of Embodiment 1
In the first embodiment, each of the divided pipes is provided by providing circumferential grooves (30, 31) in the plurality of divided pipes (2a) which are constituent elements of the outer tube portion (3) and the inner pipe (2). Although the carbon dioxide liquefied on the outer wall surface (2b) of (2a) was more guided to the inner wall surface (3a) of the outer cylinder part (3), the heat exchange capacity of the underground heat exchanger was improved. In the modification, a wick (8) is provided in place of the circumferential groove (30, 31).

  The underground heat exchange heat exchanger (1) provided with the wick (8) is shown in FIGS. Here, the geothermal heat exchanger (1) in FIGS. 8 to 11 has a different shape of the inner pipe (2). The effect of this difference in shape will be described later.

  The wick (8) is provided so as to contact both the inner wall surface (21) of the outer tube portion (3) and the outer wall surface (22) of the inner tube (2). Then, using the capillary phenomenon of the wick (8), the liquefied heat medium condensed on the outer wall surface (22) of the outer cylinder part (3) is compared with the circumferential groove (30, 31). Further, it can be more actively conveyed to the inner wall surface (21) of the outer cylinder part (3) and evaporated. Thereby, the heat exchange efficiency of the underground heat exchanger (1) can be further improved. In addition, the heat exchange efficiency of the underground heat exchanger (1) can be increased with a relatively simple configuration in which the wick (8) is simply attached to the inner wall surface (21) of the outer tube portion (3). .

  Further, in the underground heat exchanger of FIG. 8, the curved pipe portion of each divided pipe (2a) is located inside the cylindrical wall (20). In the underground heat exchanger of FIG. 9, the curved pipe portion of each divided pipe (2a) is located in the sealed space (7). In the underground heat exchanger of FIG. 10, all the bent pipe portions of the divided pipes (2a) are located inside the cylindrical wall (20). In the underground heat exchanger of FIG. 11, one of the bent pipe portions of each divided pipe (2a) is located inside the cylindrical wall (20), and the other is located in the sealed space (7). In this way, the curved pipe portion of each divided pipe (2a) may be arranged at various positions.

<< Embodiment 2 >>
The air conditioner according to the second embodiment uses the underground heat to cool and heat the room, and constitutes the air conditioning system of the present invention.

  As shown in FIG. 12, the air conditioner includes a refrigerant circuit (10) that performs a vapor compression refrigeration cycle, as in the first embodiment. The difference from Embodiment 1 is that a four-way switching valve (15) that reversibly switches the circulation direction of the refrigerant is connected to the refrigerant circuit (10), and a plurality of the underground heat exchangers (1) are formed. The outer cylinder part (3) is arranged in series-parallel.

  The four-way selector valve (15) has four ports. The first port of the four-way switching valve (15) is connected to the discharge side of the compressor (14), the second port is connected to the suction side of the compressor (14), and the third port is used for indoor heat exchange. The fourth port is connected to the first refrigerant pipe (9).

  The first state and the third port communicate with each other and the second port and the fourth port communicate with each other (the state indicated by the solid line in FIG. 12), and the first port and the fourth port communicate with each other. In addition, the second port and the third port can be switched to a second state (state indicated by a broken line in FIG. 12) in which the second port and the third port communicate with each other. The refrigerant circulation direction can be made reversible by the switching operation of the four-way switching valve (15).

  The underground heat exchanger (1) is configured by arranging a plurality of main body portions (1a) in parallel with each other. That is, the outer cylinder part (3) is arranged in series and parallel. Specifically, the four outer cylinder parts (3) are arranged in the series direction and four in the parallel direction.

  And among the plurality of outer tube portions (3) arranged in this way, in the divided unit (23) having the outer tube portion (3) arranged at the uppermost portion of each main body portion (1a), The upper end of one split pipe (2a) is connected to the branch pipe of the first connection pipe (17a), and the upper end of the other split pipe (2a) is connected to the branch pipe of the second connection pipe (17b). Yes. The first and second connecting pipes (17a, 17b) constitute the parallel inner pipe connecting member (17).

  The first connection pipe (17a) communicates with the first refrigerant pipe (9), and the second connection pipe (17b) communicates with the refrigerant pipe extending from the expansion valve (12). Each branch pipe of the first connecting pipe (17a) is provided with a first closing valve (SV1), and each branch pipe of the second connecting pipe (17a) is provided with a second closing valve (SV2). Yes.

  In the said air conditioner, since the other structure is equivalent to the heating apparatus of Embodiment 1, description is abbreviate | omitted.

-Driving action-
Next, the operation of the air conditioner will be described. In this air conditioner, the heating operation is performed when the four-way switching valve (15) is set to the first state, and the cooling operation is performed when it is set to the second state.

-Heating operation-
In the heating operation, the high-pressure refrigerant discharged from the compressor (14) flows into the indoor heat exchanger (11) through the four-way switching valve (15). In the indoor heat exchanger (11), the high-pressure refrigerant releases heat from the indoor air sent from the indoor fan (13) and condenses, and then flows out from the indoor heat exchanger (11). On the other hand, the indoor air is warmed by this condensation heat. As a result, the room is heated.

  The high-pressure refrigerant that has flowed out of the indoor heat exchanger (11) is decompressed by the expansion valve (12) to become low-pressure refrigerant, and then passes through the second connection pipe (17b), Divide each body part (1a) in 1). Since the operation of each main body (1a) is equivalent to that of the heating device of the first embodiment, description thereof is omitted. The low-pressure refrigerant that has flowed out of each main body (1a) joins via the first connecting pipe (17a), passes through the first refrigerant pipe (9) and the four-way selector valve (15), and then compresses the compressed refrigerant. Inhaled into the machine (14). In the compressor (14), the low-pressure refrigerant is compressed to a predetermined pressure and is discharged after becoming a high-pressure refrigerant, and the high-pressure refrigerant passes through the four-way switching valve (15) again to exchange the indoor heat. Flows into the vessel (11). Thus, the heating operation is performed by circulating the refrigerant in the refrigerant circuit (10).

-Cooling operation-
In the cooling operation, after the high-pressure refrigerant discharged from the compressor (14) passes through the four-way switching valve (15) and the first refrigerant pipe (9), the first connection pipe (17a ) And then divert to each main body (1a) of the underground heat exchanger (1). The operation of each main body (1a) will be described later. The high-pressure refrigerant that has flowed out of each main body (1a) joins via the second connection pipe (17b), and then flows into the expansion valve (12).

  The high-pressure refrigerant that has flowed into the expansion valve (12) is depressurized to a predetermined pressure, becomes low-pressure refrigerant, and flows out of the expansion valve (12). The low-pressure refrigerant that has flowed into the expansion valve (12) flows into the indoor heat exchanger (11). In the indoor heat exchanger (11), the low-pressure refrigerant absorbs heat from the indoor air sent from the indoor fan (13) and evaporates, and then flows out from the indoor heat exchanger (11). On the other hand, the indoor air is cooled by releasing heat. As a result, the room is cooled.

  The low-pressure refrigerant that has flowed out of the indoor heat exchanger (11) passes through the four-way switching valve (15) and is then sucked into the compressor (14). In the compressor (14), the low-pressure refrigerant is compressed to a predetermined pressure and discharged after becoming a high-pressure refrigerant, and the high-pressure refrigerant is again supplied to each main body portion (1a) of the underground heat exchanger (1). ). In this way, the refrigerant circulates in the refrigerant circuit (10), whereby the cooling operation is performed.

-Operation of underground heat exchanger-
Next, the operation of the underground heat exchanger (1) will be described.

  The high-pressure refrigerant discharged from the compressor (14) is divided and flows into the dividing pipe (2a) of the uppermost dividing unit (23) in each main body (1a). The low-pressure refrigerant that has flowed into the split pipe (2a) flows downward toward the lowermost split unit (23), and after making a U-turn in the lowermost split unit (23), the uppermost split unit ( 23) flows upward and flows out of the uppermost split unit (23). When a high-pressure refrigerant with a temperature higher than the temperature of the soil in the ground flows into the dividing pipe (2a), the saturation temperature of carbon dioxide in each sealed space (7) is between the soil and the high-pressure refrigerant. It shall be temperature.

  When high-pressure refrigerant flows into each of the divided pipes (2a), as shown in FIG. 13, unlike the heating operation, carbon dioxide in the sealed space (7) evaporates on the outer peripheral surface of the divided pipe (2a). At the same time, the heat medium gasified by the evaporation is led to the inner peripheral surface of the outer cylinder part (3) due to the density difference and condensed. Then, the heat medium condensed on the inner peripheral surface of the outer cylinder part (3) passes through the contact part of the outer cylinder part (3) and the divided pipe (2a), and the inner periphery of the outer cylinder part (3) It is transmitted from the surface to the outer peripheral surface of the dividing pipe (2a) and evaporated again on the outer peripheral surface of the dividing pipe (2a).

  By repeating the evaporation and condensation of carbon dioxide in this manner, the high-pressure refrigerant flowing inside the dividing pipe (2a) is passed through the carbon dioxide to the soil in the ground outside the outer cylindrical portion (3). The heat of the high-pressure refrigerant is released. That is, the high-pressure refrigerant in the refrigerant circuit (10) releases heat to the carbon dioxide in the sealed space (7) through the split pipe (2a), and the carbon dioxide through the outer tube portion (3). Releases the heat to the soil in the ground.

-Effect of Embodiment 2-
According to the second embodiment, by arranging the plurality of outer cylinder portions (3) in series and parallel, a plurality of outer cylinders can be obtained as compared with the case where all the outer cylinder portions (3) are arranged in series. It is not necessary to dig deeply to bury the part (3) in the ground, and it is possible to reduce the arrangement area compared to the case where all the outer cylinder parts (3) are arranged in parallel. .

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

  In the present embodiment, a plurality of sealed spaces (7) are formed in the main body (1a) by arranging a plurality of outer cylinders (3) in the axial direction. ) May be provided with at least one partition wall dividing the sealed space (7) into a plurality of divided spaces along the axial direction. In this way, the sealed space (7) is further subdivided, and the amount of carbon dioxide leaking to the outside from the outer tube part (3) can be further reduced, thereby reducing the heat exchange capacity of the underground heat exchanger. Can be minimized. Further, it is possible to maintain the evaporation performance of the liquefied carbon dioxide during the cooling operation.

  In the present embodiment, the connecting member (9) for the inner pipe is configured by the union. However, the present invention is not limited to this, and for example, a pipe joint that can be connected by simply inserting the pipe end of the split pipe (2a). May be.

  In the first embodiment, the air conditioning system is configured by a heating device, and in the second embodiment, the air conditioning system is configured by an air conditioning device. However, the present invention is not limited to this, and the air conditioning system may be configured by a cooling device. .

  In this case, the underground heat exchanger (1) constitutes a condenser, the indoor heat exchanger (11) constitutes an evaporator, and the underground heat exchanger (1) A refrigerant having a higher temperature flows in. Therefore, the outer wall surface (22) of the split pipe (2a) constitutes an evaporation surface, and the inner wall surface (21) of the outer tube portion (3) constitutes a condensation surface.

  In the underground heat exchanger (1), the circumferential groove (30, 31) and the wick (8) may be used in combination.

  In the above embodiment, the liquid conveying member is formed of a wick. However, the liquid conveying member is not limited thereto, and may be, for example, a metal porous body, a porous ceramic, a fiber assembly, or a capillary tube. A member using the phenomenon may be used.

  Moreover, in the said embodiment, although the said underground heat exchanger is assembled using the division unit (23) of all the same length, it is not limited to this, For example, the division unit (23) of different length is used. An underground heat exchanger may be assembled. If it carries out like this, after selecting a division | segmentation unit (23) according to desired heat exchange capability from the some division | segmentation units (23) from which length differs, this underground heat exchanger can be assembled.

  Moreover, in the said embodiment, although the carbon dioxide was used as a thermal medium, it is not limited to this, For example, water and ammonia may be sufficient. If it carries out like this, compared with a carbon dioxide, a use pressure range can be made low and thickness reduction of an outer cylinder part (3) can be achieved. Moreover, since water and ammonia have a larger latent heat than carbon dioxide, the amount of refrigerant sealed in the outer cylinder portion (3) can be reduced. Further, in this embodiment, the heat medium is enclosed so as to change phase between −10 ° C. and 40 ° C., but this is merely an example, and the heat medium is enclosed so as to change outside the temperature range. Also good.

  Moreover, in the said embodiment, although the said underground unit was assembled by connecting the said division | segmentation unit (23) in 1 row, it is not limited to this, As shown in FIG. 14, the said division | segmentation unit (23) A plurality of columns may be configured. This eliminates the need to dig deep holes to bury the plurality of outer tube portions (3) in the ground as compared to, for example, a case where they are arranged in series. Moreover, when the underground heat exchanger is long, it is difficult to use the heat medium uniformly over the entire surface. However, by arranging in parallel, the heat medium can be used uniformly over the entire surface.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a ground heat exchanger for exchanging heat between a heat exchange fluid and soil in the ground, and an air conditioning system using the ground heat exchanger.

It is a longitudinal cross-sectional view of the underground heat exchanger which concerns on Embodiment 1 of this invention. It is an enlarged view of FIG. It is a detailed view of the inside of the underground heat exchanger according to Embodiment 1 of the present invention. It is an enlarged view in operation | movement of the underground heat exchanger which concerns on Embodiment 1 of this invention. It is the figure which showed the opening part of the underground heat exchanger which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the underground heat exchanger which concerns on the modification 1 of Embodiment 1 of this invention. It is a refrigerant circuit figure of the heating device concerning Embodiment 1 of the present invention. It is a longitudinal cross-sectional view of the underground heat exchanger which concerns on the modification 2 of Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the underground heat exchanger which concerns on the modification 2 of Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the underground heat exchanger which concerns on the modification 2 of Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the underground heat exchanger which concerns on the modification 2 of Embodiment 1 of this invention. It is a refrigerant circuit diagram of the air conditioner concerning Embodiment 2 of the present invention. It is an enlarged view in operation | movement of the underground heat exchanger which concerns on Embodiment 2 of this invention. It is a refrigerant circuit figure of the air conditioner concerning other embodiments.

Explanation of symbols

1 Ground heat exchanger
1a Body
2 Inner pipe
2a Split tube
3 Outer tube
6 Fluid flow path (refrigerant flow path)
7 Sealed space
8 Wick (Liquid conveying member)
9 Union (connecting member for inner pipe)
10 Refrigerant circuit
23 Dividing unit (dividing unit)

Claims (17)

It has a main body (1a) formed with a fluid flow path (6) through which the heat exchange fluid flows and a sealed space (7) in which the heat medium is sealed, and the main body (1a) is embedded in the ground. A heat exchanger exchanging heat between the heat exchange fluid and the soil in the ground via the heat medium,
The main body (1a) has a plurality of outer tube portions (3) and an inner tube (2) inserted inside the plurality of outer tube portions (3),
The fluid flow path (6) is formed inside the inner pipe (2),
The sealed space (7) is formed on the inner side of each outer cylinder part (3) so as to surround an insertion portion of the inner pipe (2) inserted inside the outer cylinder part (3). An underground heat exchanger characterized by In claim 1,
The underground heat exchanger characterized in that the plurality of outer tube portions (3) are arranged in parallel, in series, or in series-parallel. In claim 2,
The inner pipe (2) is between the outer cylinder part (3) and the outer cylinder part (3) adjacent to each other in the series direction among the plurality of outer cylinder parts (3) arranged in series or series-parallel. Formed by a plurality of dividing pipes (2a) divided into each outer cylinder part (3),
Between the adjacent divided pipe (2a) and the divided pipe (2a), an in-line inner pipe connecting member (9) for connecting the divided pipes (2a) is provided. Underground heat exchanger. In claim 3,
The main body (1a) has a plurality of divided parts (23) divided in the series direction,
Each of the divided portions (23) is constituted by the outer cylindrical portions (3) and the divided tubes (2a) inserted and fixed to the outer cylindrical portions (3). Heat exchanger. In claim 3 or 4,
Among the plurality of outer cylinder parts (3) arranged in series or series-parallel, the outer cylinder part (3) and the outer cylinder part (3) adjacent in the series direction are arranged with a space in the axial direction. The space is provided with a connecting member (20) for the outer tube portion that connects the outer tube portions (3) so as to surround the inner pipe connecting member (9) for series connection. An underground heat exchanger characterized by In claim 5,
An underground heat exchanger characterized in that an opening (16) is formed at a position facing the in-line inner pipe connecting member (9) in the outer cylinder connecting member (20). . In claim 2,
Out of a plurality of outer cylinder parts (3) arranged in parallel or in series and parallel, the inner pipe for connecting the inner pipes (2) corresponding to each outer cylinder part (3) arranged in the parallel direction A ground heat exchanger comprising a pipe connecting member (17). In any one of Claims 1-7,
In the outer tube portion (3) and the inner tube (2), the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2) are substantially in contact with each other. An underground heat exchanger characterized by being arranged as follows. In claim 8,
Circumferential grooves (30, 31) are formed along the circumferential direction on the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2). An underground heat exchanger characterized by In any one of claims 1 to 9,
A liquid transport member (8) for transporting the heat medium liquefied on one surface of the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2) to the other surface. An underground heat exchanger characterized by being provided. In claim 10,
The liquid conveying member (8) is a wick, and the wick is in contact with both the inner peripheral surface (21) of the outer tube portion (3) and the outer peripheral surface (22) of the inner tube (2). An underground heat exchanger characterized by being provided. In any one of claims 1 to 11,
A ground heat exchanger, wherein the heat medium enclosed in the sealed space (7) of the outer tube portion (3) is carbon dioxide. In any one of claims 1 to 11,
The underground heat exchanger, wherein the heat medium enclosed in the sealed space (7) of the outer cylinder (3) is water. In any one of claims 1 to 11,
A ground heat exchanger characterized in that the heat medium enclosed in the sealed space (7) of the outer tube portion (3) is ammonia. In any one of Claims 1-14,
A ground heat exchanger characterized in that at least one of the plurality of outer tube portions (3) is configured to have a different axial length from the other outer tube portions (3). In any one of Claims 1-14,
The plurality of outer tube portions (3) are all underground heat exchangers characterized in that their axial lengths are all equal. The compressor (14), the heat source side heat exchanger (1), the expansion mechanism (12), and the use side heat exchanger (11) are connected to each other, and a refrigerant circuit (10) for performing a vapor compression refrigeration cycle is provided. An air conditioning system,
The underground heat exchanger according to any one of claims 1 to 16 is connected to the refrigerant circuit (10), and the heat source side heat exchanger (1) constitutes the underground heat exchanger. An air conditioning system characterized by

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