JP4485465B2 - Underground equipment in groundwater heat utilization facilities - Google Patents

Description

  The present invention relates to an underground device in a groundwater heat utilization facility, for example, direct or indirect groundwater heat to a circulating closed circuit type ground facility such as a cooling / heating facility or a snow melting facility that melts snow on a rooftop, roof, road surface, or other ground. The present invention relates to an underground device (well) constructed deeply in the ground in order to circulate and supply.

The prior art that performs pumping and reduction in a conventional well considers the pumping layer and the reducing layer as separate, and each has an aquifer to pump and aquifer to reduce, but in reality, The upper end of the casing (well) is open to the atmosphere or sealed.
And the usage method of the secondary side is not limited to an open circuit and a sealed circuit, and the system is constructed on the premise that the amount of pumped water is the same as the amount of reduction (for example, Patent Documents 1 and 2). reference).

However, originally, separate layers are not communicated with each other, and an impermeable layer exists between the aquifer and the aquifer, apart from the thickness and width of the layer. That is, an aquifer exists because an impermeable layer exists.
The amount of water discharged from the aquifer on the pumping side and the amount of seepage of the aquifer on the reduction side, the water pressure of each aquifer (water vein), the earth pressure of the impermeable layer sandwiched above and below each aquifer, etc. If the same amount of water cannot be pumped or reduced, the same amount of water cannot be pumped or reduced.

Because it means that a single casing (well) is used for circulation of pumping and reduction. If the conditions are not exactly the same, reduction of the same amount as the pumped amount is impossible. It is.
That is, because the upper or lower aquifer is pumped and reduced to the other aquifer, the conditions such as the width of the layer, water pressure, earth pressure, and head resistance at the top and bottom are always different. is there.

In this state, when the circulating movement of pumping and reduction is performed, if the amount of pumping is large and the amount of reduction is small, the amount of water can be used only for the amount of reduction.
In addition, the reverse is impossible, and the amount of water that has moved from the other to the aquifer that originally has a different water vein can only be reduced to the aquifer.
This is because even though the aquifer has a constant flow, when it is considered as one large water bottle, it is physically natural that only the amount pumped from the water bottle can be reduced, and it cannot be reduced beyond the vessel.

It is possible to secure a considerable amount of water depending on the amount of aquifers in the aquifer, but water veins are formed by infiltration of water such as rainwater and snowmelt for decades, hundreds and thousands of years. Because of various causal relationships, the overlapping depth of each aquifer, impermeable layer, etc. has been naturally constructed along with the history of the earth, and is pushed up by earth pressure and water pressure in the ground. It is easy to pump up the groundwater that has been pumped by some power pumps. Because there is an aquifer that is blowing out.
However, in other words, reducing is not possible unless the pressure is greater than the earth pressure and water pressure in the ground.
In rare cases, even if there is an aquifer that is easy to penetrate to some extent, even if it can be reduced to a layer that only constitutes the original amount of water (a constant water bottle layer), the balance will be lost, and the underground In this case, the aquifer will collapse, and the reduction layer will not be established.

  In general, it is difficult to think of an aquifer that easily permeates, and a water aquifer aquifer that physically becomes a water bottle by being sandwiched between impermeable layers such as a clay layer on the top and bottom is naturally made, so the present invention However, if it is assumed that there is no osmotic aquifer that is easy to penetrate, the technologies of Patent Documents 1 and 2 continuously operate 100% pumping and reduction with a single casing (well). It turns out that it is impossible to use and it is not practical.

JP-A-6-88327 Japanese Patent Laid-Open No. 9-280689

  Therefore, as described above, it is impossible to reduce the groundwater pumped up between the separate aquifers unless it penetrates.

The present invention has been made in view of the above-described problems, and the object of the present invention is to use the geothermal / groundwater heat of a single casing (well), and use the groundwater as a single aquifer. An object of the present invention is to provide an underground device in a groundwater heat utilization facility that can be easily returned.
Furthermore, the heat dissipation loss of groundwater heat in the well constructed deep underground is suppressed, and the rising height of groundwater due to the water pressure (ground pressure) into the well is increased, and further, the water vein leads to the upper side of the well. Groundwater convection (up-and-down movement) is promoted by the temperature difference, and groundwater heat is rationally and efficiently transferred to the circulating closed circuit type ground facility, and pumping is performed from a single (one layer) effective aquifer.・Providing underground equipment for groundwater heat utilization facilities that can be constructed as a reduction, that is, simply a “circulation” process, and that circulates and moves limited groundwater without exposing it to air. There is to do.

In order to solve the above-mentioned problems, the present invention has a casing implanted so as to reach a water vein existing at a predetermined depth in the ground, and is connected via an outgoing pipe and a return pipe, which are respectively inserted and arranged in the casing. An underground device in a groundwater heat utilization facility constructed in the ground so as to circulate and supply groundwater to a circulating closed circuit type ground facility ,
The casing is inserted and planted in the ground with the sealed upper end immersed to the ground surface or a predetermined depth in the ground, and a predetermined vertical length direction corresponding to a single aquifer existing at a predetermined depth in the ground. A strainer portion having an opening for suction and drainage on the peripheral wall of the position, the strainer portion is formed in the casing in an opening length range protruding from the upper and lower ends of the single aquifer, A water shielding pipe for dividing the interior of the casing in the vertical direction is provided within the opening length range of the strainer portion, and the forward pipe mouthpiece or the upper pipe in the upper space in the casing above the water shielding pipe One of the outlets of the return pipe is positioned, and the other is positioned in the lower space below the water shielding pipe .
Then, it is preferable to connect the water shielding pipe to the return pipe and use the water shielding pipe as the return pipe. In this case, heat was exchanged (sucked up) from the single aquifer to the circulating sealed circuit type ground facility through the outgoing pipe in which the suction port was positioned in the upper space above the impermeable pipe. It is preferable that the return groundwater is drained (returned) to the single aquifer through the outlet of the return pipe located in the lower space below the impermeable pipe through the impermeable pipe. Become.
As a form of the strainer part in the casing, a slit having a predetermined length in the vertical length direction penetrating in and out of the peripheral wall of the casing, or an opening such as a round hole or a square hole may be mentioned.

According to the above-mentioned means, a water vein having the highest water volume, that is, an effective single aquifer is divided into upper and lower portions by a water shielding pipe disposed in the casing and is circulated above the water shielding pipe to circulate ( the strainer portion), at a distance away drainage outlet below the Saegimizukan (strainer portion), the heat exchanger in a circulating closed-circuit ground facility (heat radiation) by the return ground water the temperature drops, the single in place pipe The groundwater is drained (returned) in the lower flow direction of the aquifer, and at the same time, due to the temperature difference, natural convection is generated in the single aquifer where the hot groundwater moves to the upper part of the single aquifer To do. That is, in a single aquifer, a structure and environment are constructed in which return groundwater that has been circulated back to the circulating closed circuit type ground facility is not pumped up again.
Moreover, as seen from the single aquifer side, about 1/3 of the middle of the strainer part is shielded by the water shielding pipe, so that it is below the strainer part 1/3 and the water shielding pipe in the upper space above the water shielding pipe. The strainer part 1/3 in the lower space is effective, and groundwater flows from the single aquifer side. However, the water-impervious pipe that flows into the casing from the strainer part of the upper space, passes through the outgoing pipe, is sent to the circulating closed circuit type ground facility, and is exchanged with heat (heat radiation) , the temperature drops, and communicates with the return pipe, and the lower space The groundwater that has returned to the single aquifer through the strainer part of the water falls to the bottom of the same single aquifer due to the decrease in temperature, and rides the original aquifer's original water flow. Move in the flow direction. Therefore, when the temperature difference of the water temperature in the same single aquifer comes occurred, the temperature high groundwater rises, Ru flows naturally to the upper side of the upper single aquifer than Saegimizukan While natural convection occurs, groundwater with low temperature moves in the flow direction of the aquifer while staying at the lower (bottom) side of the single aquifer.

In the present invention, it is preferable that a submersible pump is connected to the outlet of the outgoing pipe.
In this case, groundwater in the aquifer can be forcibly absorbed and supplied to the circulating closed circuit type ground facility through the outgoing pipe, so that a stable heat source for groundwater heat can be used.

Furthermore, the outlet of the outgoing pipe can be located in the lower space below the impermeable pipe, and the outlet of the return pipe can be located in the upper space above. In this case, a submersible pump is preferably connected to the outlet of the outgoing pipe located in the lower space.

Furthermore, the strainer portions are respectively provided on the peripheral walls in the vertical length direction of the casing corresponding to positions where a plurality of single aquifers having different depths exist respectively, and each strainer portion is opened. A water shielding pipe that divides the inside of the casing in the vertical direction is arranged in each opening length range, and the groundwater of each single aquifer is absorbed in the upper space above each water shielding pipe. One of the outlet of the outgoing pipe or the outlet of the return pipe that returns the groundwater to each single aquifer is positioned, and the other is positioned in the lower space below each of the water shielding pipes. be able to. -

According to the above means, in one casing (well), for example, an effective single aquifer having a water temperature of around 13 ° C. and a deeper water temperature of 20 ° C. or more (30 ° C. to 50 ° C.). The groundwater with the target water temperature is selectively sent from each effective single aquifer, etc., to the circulating closed circuit type ground facility through the respective outgoing pipes, and the groundwater is returned to the groundwater by heat exchange. Can be drained (returned) to each single aquifer through a return pipe. For example, in a circulating closed circuit type ground facility, when the time of use in a low temperature range is different from the time of use in a high temperature range, groundwater with a water temperature corresponding to each use time can be selectively used. . At the same time, it is possible to use two or more bipolar methods such as equipment that uses the temperature difference.

The underground device in the groundwater heat utilization facility of the present invention circulates the groundwater heat to the circulating closed circuit type ground facility by absorbing (pumping) groundwater and draining (reducing) groundwater within a single aquifer. It can be done easily. If a single aquifer is considered to be a large water bottle , groundwater that has been absorbed is instantaneously discharged in the same vessel at the same pressure, and the discharged groundwater is instantaneously absorbed. Circulation to the circulating closed circuit type ground equipment can be carried out smoothly.
Accordingly, it is possible to provide a groundwater device in groundwater heat utilization facilities such as a water-sprinkling type snow melting device that prevents the depletion of groundwater, prevents land subsidence, is environmentally friendly, and that effectively uses natural energy.

In addition, the outlet of the outgoing pipe is positioned in the upper space above the water shielding pipe arranged in the casing communicating with the aquifer through the strainer so as to divide the single aquifer vertically. By adopting an arrangement structure in which the outlet of the return pipe is located in the lower space below the impermeable pipe, the return groundwater whose temperature has been lowered by heat exchange (heat radiation) in the circulating closed circuit type ground facility is a single The groundwater, which is returned to the lower flow direction of the aquifer and has a high temperature, can generate natural convection in the same same aquifer that moves to the upper part of the same aquifer.
This ensures that only high-temperature groundwater is delivered in a structure and environment that does not re-pump the returned groundwater that has been circulated back to the circulating closed circuit type ground facility, even though it is in a single aquifer. In addition, it can be efficiently fed into the circulating closed circuit type ground facility for circulation.

  Further, in one casing (well), for example, an effective aquifer having a groundwater temperature of around 13 ° C. and an effective deep groundwater temperature of 20 ° C. or more (may be 30 ° C. to 50 ° C.). Bipolarization of equipment that uses a temperature difference at the same time when it is placed in each aquifer and the time to use it in a circulating closed circuit type ground facility is different from the time when the groundwater temperature is low and the time when it is used in a high temperature range Multiple usage methods are possible.

Hereinafter, an embodiment of an underground device in a groundwater heat utilization facility according to the present invention will be described with reference to the drawings.
Figure 1 is a schematic diagram showing the entire underground device in groundwater heat utilization equipment ground pump specification, in the figure, 1 is a casing to construct a deep underground wells, the interior of the casing 1, a predetermined A forward pipe 2 for transporting groundwater of a single aquifer existing at a depth to a circulating closed circuit type ground facility (in the figure, a snow melting device is shown as an example, hereinafter simply referred to as a ground facility) 16; A return pipe 3 for draining the returned groundwater whose temperature has been lowered due to heat exchange in the same aquifer is inserted . Further, a water shielding pipe 4 that divides the interior of the casing 1 vertically is connected to the lower end of the return pipe 3 within a layer height range of a single aquifer.
The upper end of the casing 1 is closed with a sealing lid 5, and the outgoing pipe 2 and the return pipe 3 project outside through the sealing lid 5, and the outgoing pipe 2 is connected to the inlet side of the ground facility 16. with 3 are respectively connected to the outlet side of the ground equipment 16, during upstream of往管second piping from the inlet side of the ground equipment 16 is connected to the forward water meter M1 and ground pump P1, the outlet side of the ground equipment 16 A return water meter M2 is connected in the middle of the downstream return pipe 3.

Further, as shown in FIGS. 1 and 2, the mouthpiece of the outgoing pipe 2 is located in the upper space above the water shielding pipe 4 that is located in the casing 1 and is located approximately in the middle of the single aquifer. The exit of the return pipe 3 that is located and communicated (penetrated) with the water shielding pipe 4 is located in the lower space below the water shielding pipe 4.
As a result, the returned groundwater from the ground facility 16 discharged from the strainer section (drain port) 6 of the casing 1 moves so as to flow in the downstream direction of the water vein at the bottom of the single aquifer. On the other hand, in the vicinity of the upper part of the single aquifer (near the water inlet), groundwater with higher temperature is introduced into the casing 1 from the strainer part (water inlet) 6 of the casing 1 from the upper direction of the water vein, and the ground pump It is sucked and transported to the ground facility 16 from P1.

The casing 1 is composed of a metal pipe, and the diameter of the casing 1 is appropriately selected from 100 mm, 125 mm, 150 mm, 200 mm, and 300 mm according to the required circulation amount of groundwater. Then, the casing having the selected diameter is inserted and planted deeply in the ground in accordance with the depth at which a single aquifer having a target temperature, amount of water, and the like exists .
In addition, although illustration is abbreviate | omitted, the casing 1 constructs | assembles one well deeply in the ground by connecting several short pipes which have a length of several meters one by one, and inserting and planting in the ground. It is supposed to be. A short pipe having a strainer portion 6 having a suction / drainage opening on the peripheral wall is inserted and planted at a position corresponding to the target single aquifer.

The strainer section 6 is an opening serving as a water inlet for allowing groundwater flowing through a single aquifer to flow into the casing 1 and a drain outlet for allowing the groundwater to flow out of the casing 1. It is formed of a group of slits 6a formed in parallel with the core and at equal intervals in the circumferential direction (see FIG. 2).
And the opening length of the strainer part 6 (slit 6a) in the up-down length direction of the casing 1 is the upper and lower ends of a single aquifer (the respective impermeable layers present above and below the aquifer). And 1 to 2 m from the boundary of the water-impermeable layer.
In addition, the strainer part 6 is not limited to a slit, What is necessary is just an opening which can go in and out of groundwater, such as a round hole or a square hole.

The impermeable pipe 4 is located within the casing 1 within the range of the opening length of the strainer portion 6 provided on the peripheral wall of the casing 1 so as to correspond to the position where a single aquifer exists, and the suction mouth of the outgoing pipe 2 is located. It is divided into a water-absorbing side and a drain side where the outlet of the return pipe 3 is located. That is, in a single aquifer, a water absorption side where high temperature groundwater is absorbed, and a drainage side where low temperature returned groundwater returned after heat exchange with the ground facility 16 is drained. The inside of the casing 1 is divided into an upper space side and a lower space side so that groundwater with different temperatures does not interfere.
And this impermeable pipe 4 is long enough to ensure the distance between the water inlet side and the water outlet side within the opening length range of the strainer part 6 so that the groundwater having a high temperature and the groundwater having a low temperature do not interfere with each other. (For example, about 3 to 5 m).
Thereby, for example, when the water shielding pipe 4 is disposed in the central portion (substantially central portion of a single aquifer) within the range of the opening length of the strainer portion 6, the opening length direction of the strainer portion 6. 1/3 to 1/4 of the water in the casing 1, and the vertical flow of groundwater in the casing 1 is blocked.
In addition, as shown in FIG. 2, the water shielding pipe 4 is provided with a water shielding material 7 that is in close contact with the inner peripheral surface at a fixed position in the casing 1 and exhibits a water blocking effect in the longitudinal direction of the outer peripheral surface. There are several.

  In addition, when the inner diameter of the casing 1 is 100 mm and a submersible pump is used, the water shielding pipe 4 is formed in a part of the outgoing pipe 2 in a single aquifer, but other basics are used. In such a configuration, a water shielding pipe 4 is connected to a part of the return pipe 3 in a single aquifer.

The water shielding material 7 has some flexibility so that the water shielding pipe 4 can move to some extent while being in contact with the inner peripheral surface of the casing 1, and expands in volume by containing water over time, and the inner surface of the casing 1 and the water shielding pipe. Materials that enhance the adhesion of the outer surface, such as cork having water content, rubber (only for water shielding), swollen rubber, and the like can be used.
As shown in FIG. 2, the water shielding material 7 is attached at three positions, that is, the upper end side and the lower end side of the water shielding tube 4 and the middle of the length of the water shielding tube 4. not, or to place the upper and lower side two places Saegimizukan 4, it is optional to mount the entire Saegimizukan 4.

By the arrangement, and the casing 1 are allowed to reach the vein of the well itself in a sealed state, and evacuated in such air vent or a vacuum pump 8 shows the air in the above the Saegimizukan 4 in FIG. 1, the casing 1 A closed circuit is constructed so that air that has the effect of atmospheric pressure does not enter the air and is blocked from outside air.
As a result, water flow movement due to temperature difference can be expected within the same pressure, so that the heat exchanger is directly pumped into the casing 1 and heat is exchanged so that the groundwater is not directly discharged to the outside. It is also possible to facilitate heat transfer.

As a result, groundwater can be absorbed from the listing (upper part) of a single aquifer, and groundwater whose temperature has decreased due to heat dissipation can be drained to the lower part ( lower part) . The low-temperature part moves in the flow direction so as to crawl the lower part of the aquifer, so that the listed groundwater with temperature enters the listing of the impervious pipe.

Below, the boring construction procedure etc. of the above-mentioned underground apparatus are demonstrated.
(1) Based on the records of civil engineering geological surveys of each prefecture (some of which are publicly available on the website, etc.) Analyze the permeable geology (sand gravel, sand, coarse sand, pebbles, gravel) that forms the water layer, and determine the drilling depth while considering the depth of the layer. 50m, 75m, 100m, 150m
Etc. Predict the aquifer at a greater depth if necessary. Also, the diameter of the casing is 100mm, 125mm, 150mm, 200 depending on the required amount of groundwater circulation.
It selects from mm and 300 mm suitably.

(2) The excavation is started while determining the depth, and the amount, size and depth of the core (scraps discharged from the excavated soil, sand, stone, gravel, etc.) that change according to the excavation depth. By checking the geology of the stratum and checking it, etc., create a columnar figure and a well log.

(3) During drilling, bet knight (a dedicated material for lubrication and water shielding) is mixed so that the excavation hole does not collapse due to the soil, and drilling is proceeded to the planned depth while blocking water.

(4) After excavating to the planned depth, promptly correct it with the logging at the time of excavation by current measurement device, etc., grasp the distribution of the stratum with respect to the depth, and determine the effective aquifer. To do.

(5) Position the confirmed aquifer and adjust the depth of the aquifer above and below the aquifer depth accordingly.
The casing 1 having the strainer portion 6 with the slit 6a having a length of ˜2 m is positioned and connected to the casing 1 to prepare for insertion.

(6) If the operations of (4) to (5) are not performed promptly at the same time on the same day after boring, the excavation pit will collapse, so the casing 1 of (5) is inserted promptly.

(7) After inserting the casing 1 , drain the groundwater until the turbidity of the aquifer has subsided while draining the muddy water mixed with bed night during excavation. While confirming whether bed nights can be removed and the groundwater pumping capacity has the capacity to discharge to the target amount of water, a certain amount of water is discharged and the well is expected to produce an underwater dome (tentative name) in the aquifer. Wash.
(Confirm that the amount of water in the aquifer is stable in order to wash away sand, mud, bed nuts, etc. sandwiched between the aquifer and the inner surface of the casing and the joints of the slits.)

(8) After the process of (7), insert a test submersible pump that can temporarily provide more pumping than necessary, and the pumping water level. ) And the depth of the natural water level (position where the water column pressure such as ground pressure and groundwater pressure is balanced) and the atmospheric pressure are selected, and the specifications of the pump installed on the ground or the submersible pump are selected.

(9) From the results of (8), select a submersible pump if the pumped water level is lower than -7m from GL, and if it is higher than -7m, select a pump installed on the ground within the range of the design water volume. With these selections, ground pumps (inner pumps with a casing inner diameter of 125 mm
If the same applies to the above case, the water shielding pipe 4 having a length of about 3 to 4 m in the center of the aquifer (the length of the water shielding pipe is approximately 1 / the depth of the aquifer). 3 to 1/4) is installed, and the tip of the return pipe connected to the lower end of the water shielding pipe 4 is the casing so that the position of the water shielding pipe 4 can be adjusted.
Provide a vertical adjustment margin so as not to reach the bottom of 1 . A slit 3a for drainage is formed on the peripheral wall of the return pipe 3 (see FIG. 2).

(10) Place the suction port of the outgoing pipe 2 (or a submersible pump if the casing inner diameter is 125 mm or more) above the water shielding pipe 4 and deeper than the pumped water level, and the outgoing pipe 2 and the return pipe 3 are Heading to the ground facility 16 , the sealing lid 5 at the upper end of the casing 1 is in a sealed state, and the connection part of the outgoing pipe 2 and return pipe 3 that goes outside the casing 1 has a connection structure that can maintain the sealing, preventing the ingress of air, The connection with the ground equipment 16 similarly constitutes a closed circuit (FIG. 1).
FIG. 3).

(11) When the inner diameter of the casing 1 is 100 mm, since the outer diameter of the submersible pump is about 97 mm, there is almost no gap between the inner surface of the casing 1 and the outer peripheral surface of the submersible pump 10, and therefore the return pipe 3 is passed through the gap. It cannot be guided down. So in this case,
The submersible pump 10 is arranged under the impermeable pipe 4, the return pipe 2 is positioned above the impermeable pipe 4, and the pipe connected to the submersible pump 10 and the impermeable pipe 4 becomes the outgoing pipe 2. It is circulated in the opposite direction.
However, the roles of the outgoing pipe 2 and the return pipe 3 are the same, and go to the ground equipment 16 on the ground in parallel. (Ten
) (See FIG. 4).

In the above-described embodiment, water absorption and drainage are performed in a single effective aquifer. However, a single well uses a plurality of single aquifers having different depths in the ground at the same time. It can also be.
The configuration will be briefly described below with reference to FIGS.
In the same casing 1, three impermeable pipes 11, 12, and 13 are inserted and arranged in the same manner as in the above embodiment, and the uppermost impermeable pipe 11 is positioned in a single upper aquifer A. The lowermost water shield 13 is located in the lower single aquifer B, and the middle water shield 12 is formed between the upper single aquifer A and the lower single aquifer B. It is located in the impermeable layer C between. The middle impermeable pipe 12 is for shielding the groundwater of the upper single aquifer A and the lower single aquifer B so as not to interfere with each other.
And, in the impermeable pipe 11 arranged in the upper single aquifer A, the outgoing pipe 2B and the return pipe 3B of the impermeable pipe 13 arranged in the lower single aquifer B penetrate the piping. In addition, the outgoing pipe 2 </ b> A is connected to the lower end of the water shielding pipe 11.
In addition, the impermeable pipe 12 disposed in the impermeable layer C is provided with an outgoing pipe 2B and a return pipe 3B of the impermeable pipe 13 arranged in the lower aquifer B.
Furthermore, only the forward pipe 2 </ b> B is connected to the water shielding pipe 13 disposed in the single lower aquifer B.

And by the said structure, the single aquifer A (within a comparatively shallow depth of less than 100 m) in which the effective depth in which a groundwater temperature is around 13 degreeC in one well differs, and a deeper groundwater temperature is 20 The time when the effective single aquifer B having a temperature higher than or equal to 0 ° C. (or 30 to 50 ° C.) is used in the ground facility 16 in the low temperature range and the high temperature range is different. When it is used, it is possible to use two or more bipolar devices such as a facility that utilizes a temperature difference.

In each of the above-described underground devices shown in FIGS. 1 to 7, it has been described as a device configured to circulate groundwater heat directly to the ground facility. However, FIG. 8 does not circulate groundwater heat directly in the ground facility for the following purpose. In addition, a heat medium (for example, antifreeze) that has been forcedly circulated in the casing 1 using a submersible pump and absorbed (heat exchanged) from a pipeline serving as a heat exchanger is circulated to the ground facility to extract groundwater heat. It is.

1. In ground facilities, it may be difficult to withstand use as a direct heat medium due to the components of groundwater. For example, there are too many iron and sulfur components, and the thin copper tube of the cold water-based fan coil may be corroded and oxidized, resulting in clogging and deterioration, which may shorten the service life.
2. When used for snow melting systems, if the groundwater temperature does not reach the required temperature, if it is possible to freeze if used directly on the ground equipment, it is safer to exchange heat using antifreeze as a heat medium first. .
3. Heat can be exchanged in the shortest distance than placing a heat exchanger on the ground, so heat loss can be prevented and space for heat exchangers on the ground equipment.
4). In areas where there are “groundwater pumping regulations” due to land subsidence and pollution regulations of each prefecture, it is possible to respond without pumping the groundwater to the ground at all. That is, it is possible to circulate only in the underground casing without pumping, and to exchange heat, thereby making it possible to use groundwater heat regardless of regulations.
5). Since the pipeline that serves as a heat exchanger communicates with the ground equipment, groundwater does not circulate directly, so it does not affect the groundwater pressure and ground pressure in the aquifer. Even if it is not, it can be used effectively in either a semi-sealed or open circuit.

Hereinafter, FIG. 8 will be briefly described. In addition, the same code | symbol is attached | subjected about the same component as shown in the said Example, and the description is abbreviate | omitted.
The pipeline 14 ′ of the heat exchanger 14 is inserted into the upper portion of the water shielding pipe 4 in the casing 1 shown in the above embodiment, and the pipeline 14 ′ is connected to the ground facility 16. Then, a medium liquid (for example, an antifreeze liquid) is injected into the pipeline 14 ′ and radiated by the ground facility 16, and then enters the lower portion of the heat exchanger 14 in the casing 1 and rises while being heat-exchanged. The circulation process to is performed.
In the forced convection device 17, the submersible pump 10 is attached above the heat exchanger 14, and the groundwater above the single aquifer flows from the strainer portion 6 of the casing 1 , and the gap of the heat exchanger 14 is removed. The water is forcibly sucked into the upper submersible pump 10 while exchanging heat, passes through the return pipe 15 communicated with the outlet of the submersible pump 10 and turned back toward the lower part, and further passes through the water shielding pipe 4 communicated with the return pipe. Water is drained from the strainer portion 6 of the casing 1 through the 15 slits.
According to the underground apparatus having such a configuration, the heat flow is fast and the heat exchange is easy because of the heat exchange by the operation of the submersible pump 10 only in the casing 1, and the groundwater stays only in the casing 1 . Therefore, it is possible to provide an underground apparatus in a groundwater heat utilization facility that does not touch air, does not flow out, and is free from contamination and ground subsidence.

BRIEF DESCRIPTION OF THE DRAWINGS The whole schematic of the groundwater heat utilization equipment which shows an example of the underground apparatus which concerns on this invention. (A) is an enlarged view of the vicinity of the water shielding pipe of FIG. 1, (b) is an explanatory view showing an insertion state of the water shielding pipe with respect to the casing. The whole schematic diagram which shows the form which connected the submersible pump to the lower end of the outgoing pipe which has an internal diameter of a casing of 125 mm or more and is located above a water shielding pipe. An overall schematic diagram in which an inner diameter of a casing is 100 mm, a submersible pump is connected under a water shielding pipe to form an outgoing pipe, and a return pipe is disposed above the water shielding pipe. (A) is an enlarged view of the connection between the water shielding pipe and the submersible pump in FIG. 4, and (b) is an explanatory view showing a state in which the submersible pump connected to the water shielding pipe is inserted into the casing. 1 is an overall schematic diagram of a groundwater heat utilization facility that uses groundwater of a plurality of aquifers having different depths in one casing (well). (A) is the elements on larger scale of FIG. 6, (b) is a partially notched enlarged view which shows the piping state of the outgoing pipe with respect to a water-impervious pipe, and a return pipe. The whole schematic diagram of the underground apparatus which shows the other Example which inserted and arranged the forced convection apparatus and the heat exchanger in the casing.

Explanation of symbols

A, B ... Aquifer C ... Impervious layer
DESCRIPTION OF SYMBOLS 1 ... Casing 2, 2B ... Outgoing pipe 3, 3B ... Return pipe 4, 11, 12, 13 ... Impermeable pipe
5 ... Sealing lid 6 ... Strainer section
7 ... Water shielding material 8 ... Vacuum pump
10 ... Submersible pump 4 ... Heat exchanger
16 ... Circulating closed circuit type ground equipment

Claims (5)

The casing (1) is planted so as to reach a water vein existing at a predetermined depth in the ground, and is connected via an outgoing pipe (2) and a return pipe (3) respectively inserted and arranged in the casing (1). An underground device in a groundwater heat utilization facility constructed in the ground so as to circulate and supply groundwater heat to the circulating closed circuit type ground facility (16) ,
The casing (1) is inserted and planted in the ground with the sealed upper end immersed to the ground surface or a predetermined depth in the ground, and has a vertical length corresponding to a single aquifer existing at a predetermined depth in the ground. A strainer portion (6) having an opening for suction and drainage on a peripheral wall at a predetermined position in the direction;
The strainer portion (6) is formed in the casing (1) with an opening length range protruding from the upper and lower ends of the single aquifer,
The casing above the water shield pipe (4) is provided with a water shield pipe (4) for dividing the inside of the casing (1) vertically within the opening length range of the strainer section (6). (1) Either one of the outlet of the forward pipe (2) or the outlet of the return pipe (3) is positioned in the upper space inside, and the other is positioned in the lower space below the water shielding pipe (4). An underground device in a groundwater heat utilization facility characterized by having been made . By connecting the water shielding pipe (4) to the return pipe (3), the return groundwater heat-exchanged by the circulating sealed circuit type ground facility (16) is located in the lower space through the water shielding pipe (4). The outlet of the return pipe (2) is drained back to the single aquifer, and the outlet of the forward pipe (2) is connected to the strainer section (6) in the upper space. The underground apparatus in the facility for utilizing groundwater heat according to claim 1, wherein the underground apparatus is located within an opening length range . The underground apparatus in the groundwater heat utilization facility according to claim 2, wherein a submersible pump (10) is connected to the suction port of the outgoing pipe (2) . The outlet of the outgoing pipe (2) is positioned in the lower space below the water shielding pipe (4), and the submersible pump (10) is connected to the suction mouth via the water shielding pipe (4), The underground apparatus in the groundwater heat utilization facility according to claim 1 , wherein an outlet of the return pipe (3) is positioned in the upper space above the water shielding pipe (4) . The strainer portion (6) is provided on the peripheral wall in the vertical length direction of the casing (1) corresponding to the position where each of a plurality of single aquifers (A, B) having different depths exists. A water shielding pipe (11, 12, 13) that divides the inside of the casing (1) vertically into each opening length range in which each strainer portion (6) opens, and Outlet (2B) inlet or each single aquifer that absorbs the groundwater of each single aquifer (A, B) into the upper space above each impermeable pipe (11, 12, 13) Either one of the outlets of the return pipe (3B) for returning the groundwater to the layers (A, B) is located, and the other is located in the lower space below each of the water shielding pipes (11, 12, 13). in groundwater heat utilization equipment according to claim 1, characterized in that Medium apparatus.

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