JP2007024342A - Geothermal heat collecting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geothermal heat collecting system capable of saving heat medium transporting power. <P>SOLUTION: This geothermal heat collecting system 1 which comprises an underground vessel 15 mounted under a ground level G and storing a first heat medium M1, and a heat exchanging flow channel 10 having an internal flow channel 11r in which the first heat medium M1 flows, an external flow channel 12r formed to receive the internal flow channel 11r to allow the first heat medium M1 to flow in the direction opposite to the flow in the internal flow channel 11r, at an outer side of the internal flow channel 11r, and in which the heat exchanging flow channel 10 is mounted under the ground level G horizontally or in a state of having a downward gradient when observed from the underground vessel 15, heat exchange is performed between the heat of the first heat medium flowing in the external flow channel and the underground heat, and the first heat medium is convected by the change of concentration of the first heat medium, thus the geothermal heat can be collected without using power. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a geothermal heat collection system, and more particularly to a geothermal heat collection system with reduced heat medium conveyance power.

  Among so-called global environmental problems, there is a concern that rapid climate change will cause changes in rainfall patterns and sea level rise as carbon dioxide emissions increase and will have a major impact on human society. . Against this background, systems that use continuously released geothermal heat as renewable energy have begun to be adopted in recent years as a form of natural energy utilization.

Exemplifying a system that uses geothermal heat, drilling holes in the horizontal direction parallel to the underground aquifer from the side wall of the storage tank installed under the ground surface into the ground, providing the drill hole, A multi-tube ground comprising a heat medium supply pipe for flowing a heat medium toward a heat medium water pipe arranged in the section and a heat collection pipe for collecting the heat of groundwater while flowing the heat medium introduced from the heat medium water pipe An intermediate heat exchanger is inserted into this excavation hole, the ground heat exchanger is sampled by circulating the heat medium in the underground heat exchanger with a heat medium circulation pump, and air conditioning, hot water supply, snow melting, snow removal, agricultural greenhouses, etc. There is a system used as a heat source (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2002-147892 (FIG. 1, FIG. 3, etc.)

  In the geothermal utilization system using natural energy as described above, if energy consumption can be further reduced, it will contribute to the conservation of the global environment. For example, in the above-described system, if a heat medium circulation pump for circulating the heat medium in the underground heat exchanger can be omitted, it will contribute to further energy saving.

  An object of this invention is to provide the geothermal heat collection system which reduced the conveyance power of the heat medium in view of the above-mentioned subject.

  In order to achieve the above object, a geothermal heat collecting system according to the first aspect of the present invention is provided in the ground surface G, for example, as shown in FIG. A container 15; an internal flow path 11r through which the first heat medium M1 flows; and an internal flow path 11r that is disposed so as to accommodate the outside, and the outside of the internal flow path 11r is opposite to the flow direction in the internal flow path 11r A heat exchange flow path 10 having an external flow path 12r through which the first heat medium M1 flows, and so that the heat exchange flow path 10 has a downward slope horizontally or when viewed from the underground container 15 It is disposed below the ground surface G.

  If comprised in this way, heat exchange will be performed between the heat of the 1st heat carrier which flows through an external channel, and the heat of the ground, and the 1st heat carrier will change because the density of the 1st heat carrier changes. Convection. Therefore, geothermal heat can be collected without using power.

  Moreover, the geothermal heat collection system which concerns on invention of Claim 2 is provided with multiple heat exchange flow paths 10 in the geothermal heat collection system of Claim 1 as shown, for example in FIG. 2; Heat exchange flow path 10 are arranged radially on the horizontal projection plane.

  If comprised in this way, the heat-transfer area at the time of heat exchange will be increased between the heat of the 1st heat carrier which flows through an external channel, and the heat of the ground, and the amount of heat collection of geothermal heat will increase.

  In addition, the geothermal heat collecting system according to the invention described in claim 3 is the geothermal heat collecting system according to claim 1 or 2, as shown in FIG. ), A pumping pump 21 for pumping groundwater Wu below; and a pumping pump 22 for pumping groundwater Wu; and a spraying pump 25 for spraying pumped groundwater Wu above the heat exchange channel 10. .

  With this configuration, the groundwater around the heat exchange channel flows to replace the groundwater that has exchanged heat with the first heat medium, and the heat is exchanged between the heat of the first heat medium and the underground heat. The heat exchange efficiency is improved.

  Moreover, the geothermal heat collection system according to the invention described in claim 4 is the heat exchange flow path in the geothermal heat collection system according to any one of claims 1 to 3, for example, as shown in FIG. 10 is configured such that the cross-sectional area of the external flow path 12r is larger than the cross-sectional area of the internal flow path 11r.

  With this configuration, the flow rate of the first heat medium is slower in the external flow path than in the internal flow path, and the unit of the heat of the first heat medium flowing in the external flow path and the heat in the ground The amount of heat exchanged per flow rate can be increased.

  Further, the geothermal heat collection system according to the invention described in claim 5 is the geothermal heat collection system according to any one of claims 1 to 4, for example, as shown in FIG. Is opened at a position deeper than ½ of the depth of the first heat medium M1 in the underground container 15; one end 12a of the external flow path 12r is opened at one end 11a of the internal flow path 11r. It is configured to be opened above the position.

  If comprised in this way, temperature stratification will be formed in an underground container and it will become easy to utilize the heat by the secondary side. Here, the heat utilized on the secondary side is warm or cold.

  Moreover, the geothermal heat collection system according to the invention described in claim 6 is the geothermal heat collection system according to any one of claims 1 to 4, as shown in FIGS. 3 and 4, for example. One end 11a of the flow path 11r or one end 12a of the external flow path 12 is connected to transfer devices 31 and 32 that transfer the first heat medium M1.

  If comprised in this way, the 1st heat medium which has just performed heat exchange with underground can be utilized by the secondary side, and a heat loss will decrease.

  In addition, the geothermal heat collection system according to the invention described in claim 7 is the geothermal heat collection system according to any one of claims 1 to 4, for example, as shown in FIG. One end 11a of the external flow path 12 and one end 12a of the external flow path 12 are connected to the heat pump chiller 34.

  If comprised in this way, it will become possible to supply the heat-collected geothermal heat to a heat pump chiller without using motive power, and to manufacture cold water or warm water.

  Moreover, the geothermal heat collection system according to the invention described in claim 8 is the geothermal heat collection system according to any one of claims 1 to 4, for example, as shown in FIG. A heat source device 35 that performs at least one of heating and cooling with respect to the medium M2; an outdoor unit 36 of the heat source device 35 installed inside the underground container 15; and an inside of the underground container 15 above the outdoor unit 36 And a blower 38 having one end 11a of the internal flow path 11r connected to the discharge side; one end 12a of the external flow path 12r is an underground container having a height equal to or less than the height of the air inlet 36a formed in the outdoor unit 36 15 is open.

  If comprised in this way, the 1st heat medium which heat-exchanged with the underground heat can be supplied to an outdoor unit, and the efficiency of a heat source apparatus can be improved.

  A geothermal heat collection system according to the invention described in claim 9 is the geothermal heat collection system according to any one of claims 1 to 3, for example, as shown in FIG. Instead of 10, a heat pipe 16 having a part disposed inside the underground container 15 is provided.

  If comprised in this way, geothermal heat can be collected even if it does not use motive power. In particular, when a two-phase working medium is enclosed in a heat pipe, it becomes possible to use latent heat, and the amount of exchange heat increases.

  Moreover, the geothermal heat collection system according to the invention described in claim 10 is the geothermal heat collection system according to claim 9, for example, as shown in FIG. 8, wherein the heat pipe is connected to the external passage 19 and the external passage 19. The internal passage 18 is housed, and one end 18a of the internal passage 18 and one end 19a of the external passage 19 are connected inside the underground container 15, and the other end 19b of the external passage 19 is closed. The other end 18b is opened inside the external passage 19 so as to form a circulation channel.

  If comprised in this way, since a circulation flow path is formed, since working media with different densities do not mix and mixing loss does not occur, it is possible to efficiently collect geothermal heat. In particular, when the working medium has two phases, if the amount of evaporation of the working medium increases, the circulation force increases and the heat collection efficiency improves.

  According to the geothermal heat collecting system of the present invention, the internal flow path for flowing the first heat medium, and the external flow for flowing the first heat medium on the outside of the internal flow path in the direction opposite to the flow direction in the internal flow path. Since the heat exchange flow path having the flow path is disposed horizontally or below the ground surface so as to have a downward slope when viewed from the underground container, the heat of the first heat medium flowing through the external flow path Is exchanged between the ground and the heat in the ground, and the density of the first heat medium is changed to convect the first heat medium. Therefore, geothermal heat can be collected without using power.

Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same or corresponding members are denoted by the same or similar reference numerals, and redundant description is omitted.
With reference to FIG. 1, the structure of the geothermal heat collection system which concerns on the 1st Embodiment of this invention is demonstrated. FIG. 1 is a system diagram illustrating a geothermal heat collection system 1 according to the first embodiment of the present invention. The geothermal heat collection system 1 includes a heat collection water tank 15 as an underground container, a heat collection pipe 10 as a heat exchange channel, a heat utilization pump 31 as a transfer device, and a heat utilization device 33.

  The heat collection water tank 15 is a water tank that stores water M1 as a first heat medium. Here, when simply referred to as “water”, it means liquid water that does not consider the form of heat utilization, and when considering the form of heat utilization, it is expressed as cold water or hot water. The heat collection water tank 15 is typically formed by stacking cylindrical members made of concrete. The heat collection water tank 15 is embedded in the underground G below the ground surface GL. Moreover, it is preferable that the lower part (typically about 2 m) of the heat-collecting water tank 15 is embedded in the aquifer Gb. The “aquifer” is a permeable layer that has a large gap between the particles forming the formation and is saturated with groundwater. In order to grasp the aquifer Gb of the underground G, for example, ground data to be investigated when a foundation pile of a building that uses the geothermal heat collection system 1 is placed may be used. The heat collection water tank 15 preferably has a diameter of 3 m or more in consideration of the laying of the heat collection pipe 10. Note that the heat collecting water tank 15 may be made of steel plate, FRP, or the like other than concrete.

  The heat collection pipe 10 is a pipe that exchanges heat between the water M1 and the underground G. The heat collection tube 10 includes an inner tube 11 that forms an internal channel 11r, and an outer tube 12 that extends from an external channel 12r that is formed outside the inner tube 11. The inner pipe 11 is typically a synthetic resin pipe having a high flexibility such as a cross-linked polyethylene pipe or a polybuden pipe from the viewpoint of workability. However, the inner pipe 11 is a rigid polyvinyl chloride pipe, a steel pipe, or a cylindrical section. Other square pipes may be used. The outer tube 12 is typically a polyethylene corrugated tube, but may be a cross-linked polyethylene tube, a polybden tube, a hard vinyl chloride tube, a steel tube, or the like, and may have a shape other than a circular cross section. However, a polyethylene corrugated pipe is preferable because it has excellent corrosion resistance and is inexpensive. The heat collecting tube 10 is arranged and formed so that the inner tube 11 is accommodated in the outer tube 12. Further, it is preferable that the inner tube 11 and the outer tube 12 are arranged coaxially using a spacer (not shown) or the like. It is preferable to use a spacer with as little resistance as possible so as not to disturb the flow of the water M1 in the external flow path 12r. In order to easily obtain a spacer, using a binding band made of a synthetic resin having a large repulsive force, a plurality of binding bands are connected to the inner tube 11 such that the surplus portion extends in the radial direction in all directions. You may comprise by cut | disconnecting to predetermined length.

  The size of the inner tube 11 and the outer tube 12 constituting the heat collecting tube 10 may be determined so that the cross-sectional area of the external flow path 12r is larger than the cross-sectional area of the internal flow path 11r. If the cross-sectional area of the external flow path 12r is larger than the cross-sectional area of the internal flow path 11r, the flow speed of the external flow path 12r is slower than the flow speed of the internal flow path 11r. This is because M1 has a larger amount of exchange heat with the underground G than that with water M1 flowing through the internal flow path 11r. Although the length of the heat collection pipe | tube 10 is based also on the site area to install, it is good to set it as about 25-30m. If it is too short, the amount of heat collected decreases, and if it is longer, the construction cost increases.

  The heat collection tube 10 is embedded in the groundwater aquifer Gb. The heat collection pipe 10 is embedded so as to extend horizontally from the underground water tank 15 or to extend with a downward slope as viewed from the underground container 15. By being buried with a horizontal or downward slope, the water M1 is configured not to stay in the end portion of the heat collecting tube 10 even if the density changes. When the lower part of the underground water tank 15 is buried in the aquifer Gb, the heat collecting pipe 10 is arranged horizontally from the wall surface of the underground water tank 15 in the aquifer Gb part or so that the end does not come off from the aquifer Gb. It is laid with a downward slope. When the lower part of the underground water tank 15 does not reach the aquifer Gb, the heat collecting pipe 10 is laid with a downward slope so that a portion embedded in the aquifer Gb increases. A preferable angle of the downward gradient is 10 ° to 40 ° with respect to the horizontal, and more preferably 15 ° to 30 °. Whether the heat collecting pipe 10 is laid horizontally or with a downward slope may be determined in consideration of the flow rate of groundwater flowing in the aquifer Gb. When the groundwater flow rate is slow, heat exchange with the water M1 in the heat collection pipe 10 avoids the influence of groundwater that has moved upward (when the temperature of the groundwater rises) or downward (when the temperature of the groundwater falls) due to convection. Therefore, it is better to lay it horizontally. On the other hand, when the groundwater flow rate is high, the groundwater that has been heat-exchanged with the water M1 in the heat collecting pipe 10 may be laid with a downward slope in order to avoid a situation in which the amount of exchange heat at the end portion decreases due to movement in the horizontal direction. .

  The heat collection tube 10 is laid on the aquifer Gb as follows. Boring from the inside of the heat collecting water tank 15 with a diameter slightly larger than the outer diameter of the outer pipe 12 toward the aquifer Gb in a horizontal or downward gradient by a boring machine. Boring is performed for the length of the heat collecting tube 10 while adding a casing of about 1 m. After boring for the length of the heat collecting tube 10, the outer tube 12 of the heat collecting tube 10 is inserted into the excavation hole after closing the end. When the insertion of the outer tube 12 is completed, the casing is removed, and the inner tube 11 whose end is opened so as to be as coaxial as possible is inserted into the outer tube 12 remaining in the aquifer Gb using a spacer (not shown) or the like. . In the heat collecting pipe 10 laid as described above, the inside of the inner pipe 11 and the inside of the outer pipe 12 communicate with each other at the end portion, and the direction of the water M1 flowing inside the inner pipe 11 and the inner pipe 11 It is comprised so that the direction of the water M1 which flows through the inside of the outer pipe | tube 12 of an outer side part may become reverse.

  In the geothermal heat collecting system 1, the outer pipe 12 of the heat collecting pipe 10 extends vertically upward in the heat collecting water tank 15, and the end 12 a is below the water surface near the water surface of the water M <b> 1 stored in the heat collecting water tank 15. It is open. On the other hand, the inner tube 11 has a distal end 11a opened through the side of the outer tube 12 below the inside of the heat collecting water tank 15. The end 11a of the inner pipe 11 is opened at a position deeper than ½ of the depth of the water M1 in the heat collecting water tank 15, preferably at a position deeper than 1/5, more preferably at a position deeper than 1/7. ing. On the other hand, the end 12a of the outer pipe 12 is at a position shallower than 1/2 of the depth of the water M1 in the heat collecting water tank 15, preferably at a position shallower than 4/5, more preferably at a position shallower than 6/7. It is open. The depth ratio is viewed from the bottom of the heat collecting water tank 15. The portion of the outer tube 12 through which the inner tube 11 passes is stretched so that the water M1 in the lower part of the heat collecting water tank 15 does not enter the outer tube 12 as it is. Moreover, plate 15A is affixed on the wall of the heat collecting water tank 15 of the part which the heat collecting pipe 10 penetrates, and it is comprised so that the water M1 in the heat collecting water tank 15 may not flow out into the underground G.

A plurality of the heat collecting tubes 10 are laid radially on the horizontal projection plane with the heat collecting water tank 15 as the center.
FIG. 2 shows the laying state of the heat collecting tube 10 in the present embodiment. In the present embodiment, 20 heat collecting tubes 10 are laid, but the number may be less than this, or conversely, 30 or more may be laid. That is, what is necessary is just to determine so that the intended cold / heat amount can be heat-collected from underground G. The plurality of heat collecting tubes 10 are laid out radially at equal angular intervals around the heat collecting water tank 15. The plurality of heat collecting tubes 10 may be laid with alternating downward gradients. In the present embodiment, the heat collecting tubes 10 having a downward gradient of 15 ° with respect to the horizontal and the heat collecting tubes 10 having a downward gradient of 30 ° are laid alternately. If it does in this way, it can avoid that the groundwater in the aquifer Gb which heat-exchanged with the one heat collection pipe | tube 10 does not affect the adjacent heat collection pipe | tube 10, and reduces a heat exchange amount. Further, the heat collecting amount may be increased by laying a plurality of heat collecting tubes 10 radiated in two or more stages in the vertical direction.

  Returning to FIG. 1 again, the explanation of the geothermal heat collection system 1 will be continued. Inside the heat collecting water tank 15, an upper header 41 is disposed above and a lower header 42 is disposed below. Typically, the upper header 41 is disposed at the same height as the open end 12a of the outer tube 12, and the lower header 42 is disposed at the same height as the open end 11a of the inner tube 11. ing. Each header 41, 42 is formed with an access hole through which water M1 flows in and out. Further, a heat utilization pump 31 that conveys the water M1 in the heat collecting water tank 15 to a heat utilization place is disposed on the ground surface GL. Further, heat use devices 33 such as heat source devices such as a water-cooled heat pump chiller and heat exchange devices such as an air handling unit and a fan coil unit are installed at a place where heat is used.

  The discharge side of the heat use pump 31 and the heat use device 33 are connected by a pipe 51. The suction side of the heat utilization pump 31 is connected to the lower header 42 via a pipe 53 including a pipe 53a and a pipe 53b. An open / close valve 43 is disposed in the pipe 53a. A pipe 54 branches off from a connection portion between the pipe 53 a and the pipe 53 b and is connected to the upper header 41. An open / close valve 44 is disposed in the pipe 54. The heat utilization device 33 is connected to the lower header 42 via a pipe 55 including a pipe 55a and a pipe 55b. An open / close valve 45 is disposed in the pipe 55a. A pipe 56 branches off from a connection portion between the pipe 55 a and the pipe 55 b and is connected to the upper header 41. An open / close valve 46 is disposed in the pipe 56.

  With continued reference to FIG. 1, the operation of the geothermal heat collection system 1 will be described. As will be described below, the geothermal heat collection system 1 is a system that reduces the conveyance power by applying a so-called thermosiphon so that a pump that circulates the water M1 in the heat collection pipe 10 is unnecessary. The heat collecting water tank 15 stores water M1 up to about 3/4 of the depth. The temperature of the aquifer Gb is stable at about 15 ° C. throughout the year. Hereinafter, assuming that the collected geothermal heat is used for air conditioning of a building, it is divided into a heating time and a cooling time, and a typical operation situation will be described for each.

  First, heating will be described. During heating, the open / close valves 43 and 46 are closed, and the open / close valves 44 and 45 are open. Temperature stratification is formed in the heat collecting water tank 15, for example, warm hot water M1 of about 13 ° C. is stored in the upper part and cold hot water M1 of about 7 ° C. is stored in the lower part. The temperature of the hot water M1 in the heat collecting water tank 15 and the heat collecting pipe 10 is in the range of approximately 7 ° C to 13 ° C. This temperature is lower than the temperature of underground G (about 15 ° C.). The hot water M1 in the outer tube 12 of the heat collecting tube 10 receives heat from the aquifer Gb and the temperature rises. Since the hot water whose temperature has risen decreases in density and rises, the hot water M1 in the outer pipe 12 moves toward the heat collecting water tank 15. Thus, when a local difference arises in the density of the hot water M1 in the outer tube | pipe 12, a convection will arise by what is called a thermosiphon phenomenon. The hot water M1 that moves inside the outer pipe 12 toward the heat collecting water tank 15 receives heat from the aquifer Gb in the moving process, and the temperature rises and the density further decreases. The hot water M <b> 1 that has received heat from the aquifer Gb and has risen in temperature flows out from the end 12 a in the hot water tank 15 and is stored in the upper part of the hot water tank 15. On the other hand, as the hot water M1 in the outer pipe 12 moves toward the heat collecting water tank 15, the hot water M1 in the inner pipe 11 is drawn toward the end portion 11b communicating with the outer pipe 12. Hot water flowing through the inner pipe 11 is introduced from the end portion 11 a of the inner pipe 11 in the heat collecting water tank 15.

  Thus, the hot water of about 7 ° C. at the lower part of the heat collecting water tank 15 flows into the inner pipe 11 from the end portion 11a, flows through the inner flow path 11r, and moves to the outer pipe 12 communicating with the end portion 11b. 12, it receives heat from the aquifer Gb while flowing in the water 12, and flows out as hot water of about 13 ° C. to the upper part of the heat collecting water tank 15. At this time, the flow rate of the hot water M1 flowing through the internal flow path 11r is faster than the flow rate of the hot water M1 flowing through the external flow path 12r. Accordingly, heat exchange between the hot water M1 flowing through the internal flow path 11r and the hot water M1 flowing through the external flow path 12r is not so much, and the hot water M1 that is about 7 ° C. at the end 11a is about 8 at the end 11b. It becomes ℃. On the other hand, the hot water M1 that was about 8 ° C. at the end portion 11b flows relatively slowly in the external flow path 12r, and is sufficiently exchanged with the aquifer Gb to become hot water M1 of about 13 ° C. To the upper part of the heat collecting water tank 15. During this time, since the hot water M1 is convected by a local density difference, power for collecting geothermal heat is not required.

  The warm hot water M1 in the upper part of the heat collecting water tank 15 is sucked from the entrance / exit hole of the upper header 41 when the heat utilization pump 31 is activated, flows through the pipes 54, 53b, 51 and flows into the heat utilization apparatus 33, Here, the temperature is reduced to become cold hot water M1 used for heating. The cold hot water M1 having a lowered temperature flows through the pipes 55b and 55a, reaches the lower header 42, and flows out from the inlet / outlet hole to the lower part of the heat collecting water tank 15. The cold hot water M1 at the lower part of the heat collecting water tank 15 is again introduced into the heat collecting pipe 10 from the end portion 11a, and is discharged to the heat collecting water tank 15 after collecting the geothermal heat. Thus, geothermal heat is utilized using the circulating hot water M1 as a medium. Moreover, the utilization state of heat is monitored with a thermometer (not shown) or the like, and the heat utilization pump 31 is stopped until the heat collection water tank 15 has no available heat until it is stored.

  Next, the cooling operation will be described. During cooling, the open / close valves 43 and 46 are open, and the open / close valves 44 and 45 are closed. Temperature stratification is formed in the heat collecting water tank 15, for example, warm cold water M1 of about 25 ° C. is stored in the upper part, and cold cold water M1 of about 21 ° C. is stored in the lower part. The temperature of the cold water M1 in the heat collecting water tank 15 and the heat collecting pipe 10 is in a range of about 20 ° C. to 25 ° C. in consideration of heat loss described later. This temperature is higher than the temperature of underground G (about 15 ° C.). The cold water M1 in the external flow path 12r of the heat collecting tube 10 dissipates heat to the aquifer Gb and the temperature decreases. Hereinafter, the phenomenon of “dissipating the heat of the cold water M1 to the aquifer Gb” may be expressed as “the cold water M1 receives the cold heat from the aquifer Gb”. The cold water M1 whose temperature has decreased does not decrease to 4 ° C. (the temperature at which the density is the lowest), and moves in a direction in which the density decreases and moves away from the hot water tank 15 (the direction of the end portion 11b). Along with the movement of the cold water M1, the cold water M1 in the inner pipe 11 is pushed into the heat collecting water tank 15. Further, as the cold water M1 in the outer pipe 12 moves, the cold water M1 in the upper part of the heat collecting water tank 15 flows into the external flow path 12r from the end 12a. As can be seen from the above, the direction in which the water M1 flows through the internal flow path 11r and the external flow path 12r of the heat collecting pipe 10 is reversed between the heating time and the cooling time.

  In this way, about 25 ° C. cold water in the upper part of the heat collecting water tank 15 flows into the external flow path 12r from the end 12a, receives the cold heat from the aquifer Gb while flowing in the external flow path 12r, and receives the end 11b. It moves to the internal flow path 11r that communicates with the flow path, flows in the internal flow path 11r toward the heat collecting water tank 15, and flows out to the lower part of the heat collecting water tank 15 as cold water of about 21 ° C. At this time, the flow rate of the cold water M1 flowing through the internal flow path 11r is faster than the flow rate of the cold water M1 flowing through the external flow path 12r. Therefore, heat exchange is not performed between the cold water M1 flowing through the internal flow path 11r and the cold water M1 flowing through the external flow path 12r, and the cold water M1 that has been about 20 ° C. at the end 11b is about 21 at the end 11a. The temperature rises only to the extent that it becomes ℃. On the other hand, the cold water M1 that was about 25 ° C. in the upper part of the heat collecting water tank 15 flows relatively slowly in the external flow path 12r, and is sufficiently exchanged with the aquifer Gb to be about 20 ° C. cold water. It becomes M1 and reaches the end 11b. In addition, although the temperature rises from 20 ° C. to 21 ° C. until the cold water M1 flowing through the internal flow path 11r reaches the heat collecting water tank 15 from the end portion 11b, the amount of cold heat is lost, but the temperature rises. This has the advantage that the density of the cold water M1 is reduced and convection occurs. Thus, since the cold water M1 is convected by a local density difference, it does not require power for collecting geothermal heat.

  The cold cold water M1 at the lower part of the heat collecting water tank 15 is sucked from the entrance / exit hole of the lower header 42 when the heat utilization pump 31 is activated, flows through the pipes 53a, 53b, 51 and flows into the heat utilization apparatus 33, Here, the temperature is increased for cooling and becomes warm cold water M1. The warm cold water M1 whose temperature has risen flows through the pipes 55b and 56, reaches the upper header 41, and flows out from the inlet / outlet hole to the upper portion of the heat collecting water tank 15. The warm cold water M1 in the upper part of the heat collecting water tank 15 is again introduced into the heat collecting pipe 10 from the end portion 12a, and after collecting geothermal heat (cold heat), it flows out to the heat collecting water tank 15. Thus, geothermal heat is utilized using the circulating cold water M1 as a medium. Moreover, the utilization state of heat is monitored with a thermometer (not shown) or the like, and the heat utilization pump 31 is stopped until the heat collection water tank 15 has no available heat until it is stored.

  Next, with reference to FIG. 3, the geothermal heat collection system which concerns on the 2nd Embodiment of this invention is demonstrated. FIG. 3 is a system diagram illustrating the geothermal heat collection system 2 according to the second embodiment of the present invention. The difference between the geothermal heat collection system 2 and the geothermal heat collection system 1 is that the pipes 53a, 54, 55a, 56, the open / close valves 43 to 46, and the upper header 41 are not provided, and the outer pipe 12 of the heat collection pipe 10 is provided. It is not opened under the surface of the water in the upper part of the hot water tank 15 but is opened near the wall of the lower part of the hot water tank 15, and the inner pipe 11 is connected to the pipe 53b without being opened in the hot water tank 15. It is. Other configurations are the same as those of the geothermal heat collection system 1.

  In the geothermal heat collection system 2, the flow direction of the water M1 as the first heat medium is the same during both cooling and heating. In the geothermal heat collection system 2, when the heat utilization pump 31 is activated, the water M1 in the internal flow path 11 r of the heat collection pipe 10 is sucked up by the heat utilization pump 31. Along with this, water M1 in the heat collecting water tank 15 flows into the external flow path 12r from the end 12a of the outer tube 12 provided at the lower wall of the heat collecting water tank 15. The water M1 flowing into the external flow path 12r receives cold or warm heat from the aquifer Gb while flowing in the direction of the end portion 11b of the inner pipe 11. The received water M1 flows into the internal flow path 11r, flows through the internal flow path 11r, is pumped through the pipe 51 by the heat use pump 31 via the pipe 53b, and reaches the heat use device 33. The water M1 from which the heat or heat is taken by using the heat collected from the aquifer Gb by the heat utilization device 33 flows through the pipe 55b to the lower header 42 and flows out from the inlet / outlet hole to the heat collecting water tank 15. . The water M1 that has flowed out into the heat collecting water tank 15 flows into the external flow path 12r of the heat collecting pipe 10 again, and thereafter circulates through the heat collecting cycle in the same manner. Thus, the geothermal heat collection system 2 reduces the number of pumps because the heat utilization pump 31 that supplies the water M1 in the heat collection water tank 15 to the heat utilization device 33 also serves as a pump that causes the water M1 to flow into the heat collection pipe 10. As a result, energy loss can be reduced, and conveyance power can be reduced.

  Next, with reference to FIG. 4, a geothermal heat collection system according to the third embodiment of the present invention will be described. FIG. 4 is a system diagram illustrating a geothermal heat collection system 3 according to the third embodiment of the present invention. In the geothermal heat collection system 3, air M1 is used as the first heat medium. The configurations of the heat collecting water tank 15 and the heat collecting pipe 10 are the same as the structures of the heat collecting water tank and the heat collecting pipe in the geothermal heat collecting system 1. The geothermal heat collection system 3 includes a heat utilization fan 32 in the heat collection water tank 15 that sends air M <b> 1 obtained from geothermal heat to the heat utilization device 33. The suction side of the heat utilization fan 32 is connected to the outer tube of the heat collecting tube 10. An end 11 a of the inner pipe 11 of the heat collecting pipe 10 is opened in the heat collecting water tank 15. The discharge side of the heat utilization fan 32 is connected to the heat utilization device 33 through a duct 59. As the heat utilization device 33 in the geothermal heat collection system 3, an air-cooled heat pump package type air conditioner or an air heat source heat pump chiller is used. Further, the heat collecting water tank 15 communicates with the atmosphere on the ground surface GL via the outside air introduction duct 60 and is configured so that the outside air can be introduced into the heat collecting water tank 15.

  In the geothermal heat collection system 3, when the heat utilization fan 32 is activated, the air M <b> 1 in the external flow path 12 r of the heat collection pipe 10 is sucked into the heat utilization fan 32. Accordingly, the air M1 in the internal flow path 11r is attracted to the end portion 11b that communicates with the external flow path 12r, and the outside air taken into the heat collecting water tank 15 through the external air introduction duct 60 into the internal flow path 11r. Is introduced from the end 11a. The air M1 that has collected the geothermal heat sucked into the heat utilization fan 32 flows through the duct 59 and is sent to the heat utilization device 33, and is released to the atmosphere after the heat is utilized. The geothermal heat collection system 3 can reduce the number of fans that cause the air M1 to flow into the heat collection pipe 10, and accordingly, can reduce energy loss and reduce conveyance power. In addition, the geothermal heat collection system 3 conveys the air M1 obtained by collecting geothermal heat directly to the heat utilization place by the heat utilization fan 32 without providing the heat utilization device 33, for example, air conditioning ventilation or agricultural vinyl house. It may be used alone as a heat source.

  Next, with reference to FIG. 5, the geothermal heat collection system which concerns on the 4th Embodiment of this invention is demonstrated. FIG. 5 is a system diagram illustrating a geothermal heat collection system 4 according to the fourth embodiment of the present invention. In the geothermal heat collection system 4, water M1 is used as the first heat medium. The configurations of the heat collecting water tank 15 and the heat collecting pipe 10 in the geothermal heat collecting system 4 are the same as the structures of the heat collecting water tank and the heat collecting pipe in the geothermal heat collecting system 1. In the geothermal heat collection system 4, a heat pump chiller 34 as a water heat source is installed on the ground surface GL. The inner tube 11 and the outer tube 12 of the heat collecting tube 10 are connected to a plurality of the same type of tubes in the heat collecting water tank 15 and then connected to the heat pump chiller 34, respectively. In the geothermal heat collecting system 4, the water M1 is not directly stored in the heat collecting water tank 15. However, since the heat collecting pipe 10 for flowing the water M1 is accommodated in the heat collecting water tank 15, the heat collecting water tank 15 contains the water M1. Will be. On the secondary side of the heat pump chiller 34, a circulation passage 52 through which a refrigerant gas M2 as a second heat medium flows is disposed, and the heat utilization pump 31 and the heat utilization device 33 are provided in the circulation passage 52. Arranged in order.

  In the geothermal heat collection system 4, the water M1 circulates between the heat collection pipe 10 and the heat pump chiller 34 by convection using a thermosiphon. In winter, the hot water M1 in the external flow path 12r of the heat collecting pipe 10 exchanges heat with the aquifer Gb, the temperature rises, the density decreases, and moves upward. The hot water M1 that has risen as a result of collecting geothermal heat is introduced into the heat pump chiller 34, and is supplied after heat is applied to the refrigerant gas M2. The hot water M1 derived by applying heat by the heat pump chiller 34 and decreasing in temperature is introduced into the internal flow path 11r of the heat collecting pipe 10, and circulates so as to push out the hot water M1 in the internal flow path 11r. The refrigerant gas M2 received from the hot water M1 by the heat pump chiller 34 is introduced into the heat utilization device 33, where heat is utilized. On the other hand, in the summer, the cold water M1 in the external flow path 12r of the heat collecting tube 10 exchanges heat with the aquifer Gb, the temperature decreases, the density increases, and moves downward. The cold water M1 that has received the cold and moved downward flows and circulates so as to push out the cold water M1 in the internal flow path 11r, is introduced into the heat pump chiller 34, and is supplied after the cold is given to the refrigerant gas M2. The chilled water M1 derived from the heat pump chiller 34 that has been supplied with cold and rises in temperature is drawn downward as the chilled water M1 in the external flow path 12r of the heat collecting pipe 10 moves downward due to the density difference. It is introduced into the passage 12r and receives cold from the aquifer Gb. The refrigerant gas M2 that has received the cold heat from the cold water M1 by the heat pump chiller 34 is introduced into the heat utilization device 33, where the cold heat is utilized. The geothermal heat collection system 4 is a system that reduces the conveyance power by applying a so-called thermosiphon, eliminating the need for a pump for circulating the water M1 in the heat collection pipe 10.

  Next, a geothermal heat collection system according to the fifth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a system diagram illustrating a geothermal heat collection system 5 according to the fifth embodiment of the present invention. In the geothermal heat collection system 5, air M1 is used as the first heat medium. The configurations of the heat collecting water tank 15 and the heat collecting pipe 10 are the same as the structures of the heat collecting water tank and the heat collecting pipe in the geothermal heat collecting system 1. In the geothermal heat collection system 5, an air heat source heat pump chiller 35 as a heat source device is installed on the ground surface GL, and an outdoor unit 36 of the heat pump chiller 35 is arranged in the heat collection water tank 15. In addition, a blower 38 is provided above the outdoor unit 36 in the heat collecting water tank 15. The discharge side of the blower 38 is connected to the inner tube 11 of the heat collecting tube 10. The end 12 a of the outer tube 12 is opened in the vicinity of the air inlet 36 a of the outdoor unit 36 installed in the heat collecting water tank 15. On the secondary side of the heat pump chiller 35, a circulation passage 52 through which a refrigerant gas M2 as a second heat medium flows is disposed, and the heat utilization pump 31 and the heat utilization device 33 are provided in the circulation passage 52. Arranged in order.

  In the geothermal heat collection system 5, when the blower 38 is activated, the air M1 in the internal flow path 11r of the heat collection pipe 10 moves toward the end portion 11b, turns back at the end portion 11b, and flows into the external flow path 12r. The air M1 flowing through the external flow path 12r exchanges heat with the heat of the aquifer Gb, receives cold or warm heat, and is blown out to the lower part of the heat collecting water tank 15. The air M1 obtained by collecting geothermal heat is introduced into the outdoor unit 36 from the air inlet 36a, and is used to operate the heat pump chiller 35 as a heat source of the outdoor unit 36. The air M1 heat-exchanged by the outdoor unit 36 is discharged from the top of the outdoor unit 36, is sucked into the blower 38 disposed on the top, and is discharged again toward the internal flow path 11r. The operated heat pump chiller 35 produces cold water or hot water, and circulates the inside of the circulation flow path 52 with the heat utilization pump 31, and the cold energy or the heat stored in the cold water or the hot water is used in the heat utilization device 33. The geothermal heat collection system 5 can improve the efficiency of the heat pump chiller 35 as an air heat source by supplying the outdoor unit 36 with air M1 obtained by collecting geothermal heat.

  Next, a geothermal heat collection system according to the sixth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a system diagram illustrating a geothermal heat collection system 6 according to the sixth embodiment of the present invention. The geothermal heat collection system 6 is provided with a heat pipe 16 instead of the heat collection pipe 10 in the geothermal heat collection system 1. Further, the geothermal heat collection system 6 does not include the on-off valves 43 to 46 and the pipes 53a, 55a, 56 provided in the geothermal heat collection system 1. Except for these differences, the configuration is the same as the geothermal heat collection system 1. The heat pipe 16 is a so-called hermetic thermosiphon, in which a working medium Mw is enclosed. As the working medium Mw, a single-phase liquid such as water is typically used. Further, as the working medium Mw, for example, a two-phase mixed fluid in which water and ethanol are mixed may be used. If the working medium Mw is a single-phase liquid, the configuration is simple. If the working medium Mw is a two-phase fluid, the latent heat of vaporization can be used, and the amount of geothermal heat collected can be increased. The heat pipe 16 penetrates the lower wall of the heat collecting water tank 15 from the portion embedded in the aquifer Gb and extends upward in the heat collecting water tank 15. A fin 16f for promoting heat exchange is provided in a portion extending upward.

  The geothermal heat collection system 6 configured as described above is exclusively used for heating. The operation status of the geothermal heat collection system 6 is as follows. The working medium Mw in the portion of the heat pipe 16 embedded in the aquifer Gb receives heat from the aquifer Gb, increases in temperature, and decreases in density. The working medium Mw having a reduced density moves up in the heat pipe 16, and the working medium Mw having a relatively higher density moves down. In this way, a natural convection phenomenon occurs in the heat pipe 16. The working medium Mw whose density has decreased and has risen in the heat pipe 16 exchanges heat with the hot water M1 as the first heat medium in the heat collecting water tank 15. The hot water M <b> 1 having a temperature of about 7 ° C. at the lower part of the heat collecting water tank 15 receives heat from the working medium Mw, decreases in density, and moves to the upper part of the heat collecting water tank 15. The hot water M1 in the upper part of the heat collecting water tank 15 is about 13 ° C.

  The warm hot water M1 in the upper part of the heat collecting water tank 15 is sucked from the inlet / outlet hole of the upper header 41 when the heat utilization pump 31 is activated, flows through the pipes 53b and 51, and flows into the heat utilization apparatus 33, where It is used for heating and the temperature is lowered to become cold hot water M1. The cold hot water M1 having a lowered temperature flows through the pipe 55b to the lower header 42 and flows out from the inlet / outlet hole to the lower portion of the heat collecting water tank 15. The cold hot water M1 in the lower part of the heat collecting water tank 15 exchanges heat with the working medium Mw in the heat pipe 16 again, and the density decreases and moves to the upper part of the heat collecting water tank 15. Thus, geothermal heat is utilized using the circulating hot water M1 as a medium. Moreover, the utilization state of heat is monitored with a thermometer (not shown) or the like, and the heat utilization pump 31 is stopped until the heat collection water tank 15 has no available heat until it is stored. As described above, the geothermal heat collection system 6 is a system that reduces the conveyance power by applying a so-called thermosiphon so that a pump for circulating the water M1 in the heat collection pipe 10 is not necessary.

  Next, a geothermal heat collection system according to the seventh embodiment of the present invention will be described with reference to FIG. FIG. 8 is a system diagram illustrating a geothermal heat collection system 7 according to the seventh embodiment of the present invention. The geothermal heat collection system 7 is a heat in which the heat pipe 10 in the geothermal heat collection system 1 is formed by a double pipe in a portion embedded in the aquifer Gb and a portion in the heat collection water tank 15 is formed in a loop shape. The pipe 17 is replaced, and the working medium Mw can be circulated in the heat pipe 17 to be used for both cooling and heating. As the working medium Mw, a single-phase liquid such as water is typically used. Further, at the time of heating, as the working medium Mw, for example, a two-phase mixed fluid in which water and ethanol are mixed may be used. If the working medium Mw is a single-phase liquid, the configuration is simple. If the working medium Mw is a two-phase fluid, the latent heat of evaporation can be used, and the amount of heat collected from the geothermal heat can be increased. However, when the working medium is a two-phase fluid, it is necessary to evaporate the working medium Mw in the aquifer Gb and condense it in the collecting water tank 15 in the configuration of the geothermal heat collecting system 7 described above. It cannot be used for cooling to collect cold heat. The portion embedded in the aquifer Gb of the heat pipe 17 has the same configuration as the heat collection pipe 10 used in the geothermal heat collection system 1. That is, the heat pipe 17 includes an internal passage 18 formed by the inner tube 11 corresponding to the internal flow passage 11r of the heat collecting tube 10, and an external passage formed outside the inner tube 11 corresponding to the external flow passage 12r. 19 and the end 18b of the internal passage 18 is open near the end of the heat pipe 17 on the aquifer Gb side. Further, the end 19b of the external passage 19 is closed. On the other hand, the internal passage 18 and the external passage 19 both extend upward in the heat collecting water tank 15, and the end portion 18 a of the internal passage 18 and the end portion 19 a of the external passage 19 are connected via a connecting pipe 20. ing. The connecting pipe 20 is provided with fins 20f for promoting heat exchange. Further, a liquid reservoir 18d is formed at a portion where the angle is changed upward of the internal passage 18 in the heat collecting water tank 15. The geothermal heat collection system 7 is configured in the same manner as the geothermal heat collection system 1 except for the above differences.

  About the geothermal heat collection system 7 comprised as mentioned above, the driving | running state at the time of heating is demonstrated first. During heating, the open / close valves 43 and 46 are closed, and the open / close valves 44 and 45 are open. The working medium Mw in the external passage 19 of the heat pipe 17 receives heat from the aquifer Gb, increases in temperature, and decreases in density. The working medium Mw having a reduced density moves up in the external passage 19, and accordingly, the working medium Mw having a relatively higher density moves down the internal passage 18 that communicates with the connection pipe 20. In this way, a natural convection phenomenon occurs in the heat pipe 17, and the working medium Mw circulates in the external passage 19, the connecting pipe 20, and the internal passage 18. The working medium Mw having a reduced density and moved into the connection pipe 20 exchanges heat with the hot water M1 as the first heat medium in the heat collecting water tank 15. The hot water M <b> 1 having a temperature of about 7 ° C. at the lower part of the heat collecting water tank 15 receives heat from the working medium Mw, decreases in density, and moves to the upper part of the heat collecting water tank 15. The hot water M1 in the upper part of the heat collecting water tank 15 is about 13 ° C.

  The warm hot water M1 in the upper part of the heat collecting water tank 15 is sucked from the entrance / exit hole of the upper header 41 when the heat utilization pump 31 is activated, flows through the pipes 54, 53b, 51 and flows into the heat utilization apparatus 33, Here, the temperature is reduced to become cold hot water M1 used for heating. The cold hot water M1 having a lowered temperature flows through the pipes 55b and 55a, reaches the lower header 42, and flows out from the inlet / outlet hole to the lower part of the heat collecting water tank 15. The cold hot water M1 in the lower part of the heat collecting water tank 15 exchanges heat with the working medium Mw in the connecting pipe 20 of the heat pipe 17 again, and the density decreases and moves to the upper part of the heat collecting water tank 15. . Thus, geothermal heat is utilized using the circulating hot water M1 as a medium. Moreover, the utilization state of heat is monitored with a thermometer (not shown) or the like, and the heat utilization pump 31 is stopped until the heat collection water tank 15 has no available heat until it is stored.

  Next, the operation status during cooling will be described. During cooling, the open / close valves 43 and 46 are open, and the open / close valves 44 and 45 are closed. The working medium Mw in the external passage 19 of the heat pipe 17 receives cold from the aquifer Gb, decreases in temperature, and increases in density. The working medium Mw having a high density descends in the external passage 19 and pushes the working medium Mw in the internal passage 18 upward along with this, while the working medium Mw having a relatively low density is inside. It rises in the passage 18 toward the connecting pipe 20. In this way, a natural convection phenomenon occurs in the heat pipe 17, and the working medium Mw circulates in the external passage 19, the internal passage 18, and the connection pipe 20. The working medium Mw having a reduced density and moved into the connecting pipe 20 exchanges heat with the cold water M1 as the first heat medium in the heat collecting water tank 15. In the hot water collection tank 15, the cold water M1 exchanges heat with the working medium Mw, whereby cold water of about 20 ° C. is stored in the lower part and cold water of about 25 ° C. is stored in the upper part.

The cold cold water M1 at the lower part of the heat collecting water tank 15 is sucked from the entrance / exit hole of the lower header 42 when the heat utilization pump 31 is activated, flows through the pipes 53a, 53b, 51 and flows into the heat utilization apparatus 33, Here, the temperature is increased for cooling and becomes warm cold water M1. The warm cold water M1 whose temperature has risen flows through the pipes 55b and 56, reaches the upper header 41, and flows out from the inlet / outlet hole to the upper portion of the heat collecting water tank 15. In the heat collecting water tank 15, cold cold water M1 is sent from the lower part to the heat utilization device 33, and warm cold water M1 is returned to the upper part, so that the cold water M1 moves from the upper part to the lower part. By this movement, the cold water M1 having a high temperature flows near the connection pipe 20 of the heat pipe 17. The cold water M1 having a high temperature flowing into the vicinity of the connecting pipe 20 is cooled by exchanging heat with the working medium Mw, and is sent to the heat utilization device 33 as the cold cold water M1. Thus, geothermal heat is utilized using the circulating cold water M1 as a medium. Moreover, the utilization status of heat is monitored with a thermometer (not shown) or the like, and when there is no available heat in the heat collecting water tank 15, the heat utilization pump 31 is stopped until the heat is stored.
As described above, the geothermal heat collection system 7 is a system that reduces the conveyance power by applying a so-called thermosiphon so that a pump for circulating the water M1 in the heat collection pipe 10 is unnecessary.

  Next, with reference to FIG. 9, the modification (heat collection efficiency improvement system 9) of the geothermal heat collection system which adds to the geothermal heat collection systems 1-7 and improves heat collection efficiency is demonstrated. FIG. 9 is a system diagram of the system 9 for improving the heat collection efficiency of the geothermal heat collection systems 1 to 7. The heat collection efficiency improvement system 9 includes a pumping pump 22, a pumping pipe 21 as a pumping flow path, and a water spraying pipe 25 as a sprinkling flow path in the above-described geothermal heat collecting systems 1 to 7.

The pumping pump 22 is disposed at the bottom of a pumping well 62 excavated vertically downward from substantially the center of the bottom of the heat collecting water tank 15. The pumping well 62 has a depth within about 7 m from the bottom of the heat collecting water tank 15 and is formed so that the pumping pump 22 is disposed in the aquifer Gb. The pumping pump 22 is configured to pump up the ground water Wu existing in the lower part of the heat collecting water tank 15.
The pumping pipe 21 is arranged inside the pumping well 62 so that one end is connected to the pumping pump 22 and the other end reaches the inside of the heat collecting water tank 15. A hard polyvinyl chloride pipe is typically used for the pumping pipe 21, but a material suitable for underground burial, such as a steel pipe coated or coated on the outside, may be used.
The sprinkling pipe 25 is a pipe for sprinkling the underground water Wu pumped up by the pumping pump 22 into the underground G. The water sprinkling pipe 25 is disposed above the heat collecting pipe 10 and the heat pipes 16 and 17 in substantially the same length as the heat collecting pipe 10 and the heat pipes 16 and 17 in the same manner (see FIG. 2). . The water spray pipe 25 is embedded in the ground in the same procedure as the heat collection pipe 10 and the like. The water spray pipe 25 is typically a hard polyvinyl chloride pipe, one end of which is connected to the pumping pipe 21 via the branch pipe 23 and the other end is closed. The water sprinkling pipe 25 may be made of a material suitable for underground burial, such as a steel pipe whose exterior is coated or coated. The sprinkling pipe 25 has a number of sprinkling holes formed on the side surface for sprinkling groundwater Wu pumped up by the pumping pump 22 into the ground.

  Next, the operation of the heat collection efficiency improvement system 9 will be described. When the pumping pump 22 is activated, the groundwater Wu below the heat collecting water tank 15 is pumped by the pumping pump 22. The pumped ground water Wu flows through the pumping pipe 21 and reaches the branch pipe 23, and is distributed to the plurality of water spray pipes 25 by the branch pipe 23. The groundwater Wu in the sprinkling pipe 25 is pressurized by the pumping pump 22, flows toward the end, and is sprinkled from a large number of sprinkling holes to the aquifer Gb. The groundwater Wu sprayed in the aquifer Gb flows through the aquifer Gb through the heat collecting pipe 10 (heat pipes 16 and 17), and part of the groundwater Wu is pumped by the pumping pump 22 again. . The groundwater Wu around the heat collecting pipe 10 (heat pipes 16 and 17), which exchanges heat with the first heat medium M1 and the working medium Mw, is obtained by flowing the groundwater Wu around the heat collecting pipe 10 (heat pipes 16 and 17). Therefore, the aquifer Wb around the heat collecting pipe 10 (heat pipes 16 and 17) is not thermally saturated, and the aquifer Wb and the first heat are replaced with the groundwater Wu having a steady water temperature (about 15 ° C.). Heat exchange with the medium M1 and the working medium Mw is promoted, and the heat collection efficiency of the geothermal heat collection systems 1 to 7 is improved. Further, since the groundwater Wu pumped up by the pumping pump 22 is not used but the groundwater Wu is circulated and only the heat of the groundwater Wu is used, problems such as ground subsidence do not occur.

  In the above description, the heat collecting pipe 10 and the heat pipes 16 and 17 have been described as being directly embedded in the aquifer Gb. However, the protective pipe is formed with a large number of small holes that pass through the groundwater Wu and do not pass crushed stone. May be provided so as to cover the heat collecting tube 10 and the heat pipes 16 and 17 so as to protect them from injury.

It is a systematic diagram of the geothermal heat collection system which concerns on the 1st Embodiment of this invention. It is a top view which shows the laying state of a heat collecting pipe. It is a systematic diagram of the geothermal heat collection system which concerns on the 2nd Embodiment of this invention. It is a systematic diagram of the geothermal heat collection system which concerns on the 3rd Embodiment of this invention. It is a systematic diagram of the geothermal heat collection system which concerns on the 4th Embodiment of this invention. It is a systematic diagram of the geothermal heat collection system which concerns on the 5th Embodiment of this invention. It is a systematic diagram of the geothermal heat collection system which concerns on the 6th Embodiment of this invention. It is a systematic diagram of the geothermal heat collection system which concerns on the 7th Embodiment of this invention. It is a systematic diagram of the system which improves the heat collection efficiency of a geothermal heat collection system.

Explanation of symbols

1-7 Geothermal heat collection system 10 Heat collection pipe (heat exchange flow path)
11a One end of the internal flow path 11r Internal flow path 12a One end of the external flow path 12r External flow path 15 Heat collection water tank (underground container)
16 heat pipe 18 internal passage 18a one end 19 of internal passage external passage 19a one end of external passage 21 pumping channel 22 pumping pump 25 sprinkling channel 31 pump (conveying device)
32 fans (transport equipment)
35 Heat source equipment 36 Outdoor unit 36a Air inlet 38 Blower G Ground level M1 First heat medium Wu Groundwater

Claims (10)

An underground container provided under the ground surface and containing a first heat medium;
An internal flow path for flowing the first heat medium;
A heat exchange having an external flow path disposed so as to accommodate the internal flow path and flowing the first heat medium in a direction opposite to a flow direction in the internal flow path outside the internal flow path A flow path;
The heat exchange channel is disposed horizontally or below the ground surface so as to have a downward slope when viewed from the underground container;
Geothermal heat collection system. A plurality of the heat exchange channels;
The heat exchange channels are arranged radially on a horizontal projection plane;
The geothermal heat collection system according to claim 1. A pumping flow channel for flowing groundwater below the heat exchange channel;
A pump for pumping the groundwater;
A sprinkling flow path for sprinkling the pumped ground water above the heat exchange flow path;
The geothermal heat collection system according to claim 1 or 2. The heat exchange flow path is configured such that the cross-sectional area of the external flow path is larger than the cross-sectional area of the internal flow path;
The geothermal heat collection system according to any one of claims 1 to 3. One end of the internal flow path is opened at a position deeper than ½ of the depth of the first heat medium in the underground container;
One end of the external channel is configured to be opened above a position where one end of the internal channel is opened;
The geothermal heat collection system according to any one of claims 1 to 4. One end of the internal flow path or one end of the external flow path is connected to a transfer device for transferring the first heat medium;
The geothermal heat collection system according to any one of claims 1 to 4. One end of the internal flow path and one end of the external flow path are connected to a heat pump chiller;
The geothermal heat collection system according to any one of claims 1 to 4. A heat source device that performs at least one of heating and cooling with respect to the second heat medium;
An outdoor unit of the heat source device installed inside the underground container;
A blower installed inside the underground container above the outdoor unit and having one end of the internal flow path connected to the discharge side;
One end of the external channel is opened in the underground container below the height of the air inlet formed in the outdoor unit;
The geothermal heat collection system according to any one of claims 1 to 4. In place of the heat exchange flow path, a part of the pipe is provided with a heat pipe disposed inside the underground container;
The geothermal heat collection system according to any one of claims 1 to 3. The heat pipe has an external passage and an internal passage accommodated in the external passage, and one end of the internal passage and one end of the external passage are connected inside the underground container, and the other of the external passage The end is closed and the other end of the internal passage is opened inside the external passage to form a circulation channel;
The geothermal heat collection system according to claim 9.

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