JP2004132559A - Geothermal air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an efficient geothermal air conditioning system capable of restricting the operation cost low by using a heat characteristic of the air. <P>SOLUTION: A water circulation passage 4, in which a water supplying pump P is interposed, includes a first internal passage 12 formed of a first pipe 1 buried in the ground and a water passage 31 of a steam heat exchanger 3 provided on the ground. The air, which exchanges heat between the water inside the water passage 13 during the passing in the air passage 32 of the steam heat exchanger 3, is used for air conditioning of a building. An air circulation route 7 including a second internal passage 21 formed of a second pipe 2 buried in the ground and the first internal passage 12 is added. A screw 5 provided with a function for forming an air suction area V and a discharge area B by rotating with air action work of the water supplied to the first internal passage 12 and a function for diffusing water is arranged in the first internal passage 12. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a geothermal utilization air conditioning system that can utilize geothermal heat for building air conditioning.
[0002]
[Prior art]
Conventionally, as an air conditioning system that uses geothermal energy with little temperature change throughout the four seasons, water is circulated between the internal space of an underground pipe buried underground and a steam-water heat exchanger installed under the floor of the building, In some cases, heat is exchanged between water and air (outside air) by a heat exchanger, and the air is introduced into the interior of the building. Is stored, and the stored water is sent to a gas-water heat exchanger to exchange heat with air for air conditioning (see Patent Document 1).
[0003]
[Patent Document 1]
JP 2001-116293 A
[Problems to be solved by the invention]
However, as in the past, simply storing water in an underground pipe to exchange heat with geothermal heat means that it is difficult to improve the operating efficiency of the air conditioning system because water is a substance that does not easily conduct heat. There was a problem.
The present invention has been made under the above circumstances, and by utilizing the thermal characteristics of air, which is a substance that is more likely to conduct heat than water, is more efficient than the conventional case, and the operating cost is lower. It is an object of the present invention to provide a geothermal air-conditioning system capable of suppressing the temperature.
[0005]
[Means for Solving the Problems]
The geothermal air conditioning system according to the present invention provides a water circulation path interposed with a water supply pump, a first internal passage formed by an internal space of a first pipe buried underground, and a gas installed on the ground. A water passage of a water heat exchanger is included, and air that has exchanged heat with water in the water passage while passing through the air passage of the air-water heat exchanger is used for air conditioning of a building. An air circulation path including a second internal passage formed by an internal space of a second pipe buried underground and the first internal passage is added. In addition, the first internal passage is rotated by the action of water passing through the water circulation passage fed to the first internal passage, and is rotated by the action of water to pass through the air circulation passage to the second internal passage. A screw having a function of forming a discharge area and a function of diffusing the water to perform gas-liquid contact in the second internal passage is provided.
[0006]
According to the present invention, an air suction area and an air discharge area are formed in the first internal passage by the screw that is rotated by the action of water supplied to the first internal passage of the first pipe by the water supply pump. Therefore, the air in the air circulation path passes from the suction area to the discharge area of the first internal passage without requiring other power. Moreover, since the screw has a function of performing gas-liquid contact in the first internal passage, water droplets diffused by the screw absorb the geothermal heat in the first internal passage existing in the ground and The air efficiently contacts the air passing through the first internal passage, and the air and the water droplets diffused in the first internal passage come into direct contact to perform heat exchange. In addition, since air has better thermal conductivity than water, the air passing through the second internal passage of the second pipe buried underground exchanges heat with geothermal in a short time, and such heat exchange occurs. The air subjected to the above is sucked into the first internal passage as described above, and comes into direct contact with the diffusion water. Therefore, the water introduced from the first internal passage into the water passage of the air-water heat exchanger is closer to geothermal as compared to the case where the water is not in contact with the air in the air circulation path in the first internal passage. While the water is at a temperature and such water flows through the water passage of the steam-water heat exchanger, the air flowing through the air passage of the steam-water heat exchanger exchanges heat with the water to be used for building air conditioning. Will be done.
[0007]
As described above, the geothermal air-conditioning system according to the present invention uses air having better heat conduction than water as a heat medium for geothermal recovery. Air conditioning that is more efficient than that used for In addition, since the air used as a heat medium for geothermal recovery flows through the air circulation path by the function of a screw rotating by the action of water flowing through the water circulation path, a blower for circulating air is used. There is an advantage that it is not necessary to separately use such as.
[0008]
In the present invention, it is preferable that both the water circulation path and the air circulation path are formed as closed paths that are cut off from the outside of the paths. According to this, dust does not enter the water circulation path or the air circulation path from the outside, so that those paths are not narrowed or clogged due to adhesion or accumulation of dust, and maintenance becomes easier accordingly. Operating costs can be kept low.
[0009]
In the present invention, the outer peripheral portion of the rotation locus of the screw is close to the inner peripheral surface of the first pipe, and the outer peripheral portion of the rotational locus is formed by being diffused by the screw and attaching to the inner peripheral surface. It is desirable to be in contact with the water film. According to this, the backflow of air passing from the suction area to the discharge area in the first internal passage formed by the rotation of the screw is prevented by the water film, and the air flows from the suction area to the discharge area. Since the generated air and the diffused water are stirred by the rotation of the screw, the air and the water come into direct contact with each other efficiently. As a result, a situation occurs in which air is entrained in the water or dissolves in the water and accumulates at the bottom of the first pipe, so that the geothermal heat is further increased by the water introduced into the water passage of the steam-water heat exchanger. Efficiency is recovered, and the geothermal heat is efficiently transmitted to the air for air conditioning in the air-water heat exchanger.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is an explanatory diagram showing a main part of an embodiment of a geothermal air-conditioning system according to the present invention, FIG. 2 is an explanatory diagram showing a part of FIG. 1 in detail, and FIG. FIG. 4 is a schematic explanatory view of the steam-water heat exchanger 3.
[0011]
In FIG. 1, F indicates a floor of a building, G indicates a ground line, and a first pipe 1 made of a material having excellent rust resistance and heat conductivity, for example, a long stainless steel pipe of about 10 m in the ground. And the second pipe 2 are buried vertically, and buried at a depth where the geothermal temperature becomes a constant temperature of about 17 ° C. throughout the four seasons, for example, a depth of about 5 to 13 m. I have. On the other hand, the air-water heat exchanger 3 is installed under the floor above the ground.
[0012]
The first internal passage 12 formed by the internal space of the first pipe 1 and the water passage 31 of the steam / water heat exchanger 3 are included in the water circulation path 4. That is, the water circulation path 4 includes an outward path 41 from the bottom outlet of the first pipe 1 to the inlet of the water passage 31 of the air-water heat exchanger 3 with the water supply pump P interposed therebetween, A return path 42 extending from the outlet of the water passage 31 of the water heat exchanger 3 to the top entrance of the first pipe, and the first internal passage 12 of the first pipe 1 form an outward path 41 and a return path 42. Insulated pipes are insulated.
[0013]
The multistage screw 5 is concentrically provided in the first internal passage 12. As shown in FIG. 1 or FIG. 2, the screw 5 has blades 54 in multiple stages at a plurality of positions in the axial direction of a rotating shaft 51 rotatably supported vertically by bearings 52 and 53 attached to the first pipe 1. Is fixed. As shown in FIG. 3, the outer peripheral portion of the rotation locus of the blade 54 at each stage is close to the inner peripheral surface 11 of the first pipe 1, and the outer peripheral portion of the rotational locus of the blade 54 when the blade 54 rotates. Are in contact with the water film flowing down along the inner peripheral surface of the first pipe 1. As can be inferred from FIG. 3, the blades 54 at each stage are formed by a plurality of blade plates fixed to the rotating shaft 51 and provided with a fixed inclination angle.
[0014]
As shown in FIG. 2, a water reservoir 13 is provided above the internal space of the first pipe 1, and the terminal end 44 of the return path 42 faces the water reservoir 13. Further, the water reservoir 13 is provided with a water supply pipe 15 having a lower end facing the eccentric portion of the uppermost blade 54 of the screw 5, and water overflowing the overflow weir 14 provided in the water reservoir 13 is provided. It flows down the water supply pipe 15 and drops to the eccentric part of the uppermost blade 54 of the screw 5. The screw 5 rotates upon receiving the collision energy of water that has fallen from the water supply pipe 15 to the eccentric portion of the uppermost blade 54, and repels water that falls from the water supply pipe 15 due to the rotation. In addition to exerting the function of diffusing the air, the rotation forms an air suction area V in the upper part of the screw 5 in the first pipe 1 and the lower part of the screw 5 in the first pipe 1 An air discharge area B is formed.
[0015]
Further, as shown in FIG. 1 or FIG. 2, a water reservoir 16 is provided at the bottom in the first pipe 1, and water droplets dispersed as fine water droplets by the multi-stage screw 5 absorb geothermal heat, and this water reservoir is formed. It accumulates at 16. Here, the water depth (depth from the water surface W1 to the bottom surface of the first pipe 1) of the water stored in the water pool 16 is set to about 8 m, and the length from the top of the first pipe 1 to the water surface W1 is about 8 m. It is set to 2 m. When the water depth of the water pool 16 due to the water droplets that have absorbed the geothermal heat is set to a depth of about 8 m, the water stored in the water pool 16 can sufficiently collect the surrounding geothermal energy. In addition, the lower end of the pipe forming the outward path 41 of the water circulation path 4 is opened laterally at the bottom of the water reservoir 16 as shown in FIG. Therefore, when the pump P is operated, the water that has collected in the water pool 16 and has recovered geothermal heat is sucked up from the opening 45 into the outward path 41 and introduced into the water passage 31 of the steam-water heat exchanger 3.
[0016]
For this reason, as shown in FIG. 1, the outside air introduction path 61 and the outside air derivation path 62 are connected to the air passage 32 of the air-water heat exchanger 3, and the outside air derivation path 62 is connected to the inside of a building wall, attic, room, etc. The outside air introduced from the outside air introduction passage 61 into the air passage 32 exchanges heat with the water flowing through the water passage 31 while passing through the air passage 32, and passes through the outside air discharge passage 62 to the wall of the building. Air conditioning is performed inside, in the attic, or inside the room.
[0017]
However, since water is a substance that is unlikely to cause heat conduction, as described above, fine water droplets are diffused into water droplets by the multi-stage screw 5 to absorb geothermal heat, or a water pool portion having a water depth of about 8 m. Even if the geothermal energy is recovered by the water of No. 16 and the outside air and the water are exchanged by the heat exchanger 3, the outside air guided to the inside of the wall of the building, the attic, the room, etc. through the outside air outlet path 62 is removed. It is not easy to control the temperature at which satisfactory air conditioning can be performed. On the other hand, it is conceivable to collect water for a long time by storing water in the water reservoir 16 for a long time. However, in such a case, the amount of water circulated in the water circulation path 4 is reduced, and the steam-water heat exchanger is reduced. The efficiency of geothermal recovery due to the outside air in 3 decreases, and satisfactory air conditioning cannot be performed.
[0018]
Therefore, in this embodiment, the air circulation path 7 including the second internal passage 21 formed by the internal space of the second pipe 2 buried underground and the first internal passage 12 is added. That is, in the present embodiment, attention is paid to the fact that air has a heat characteristic of recovering geothermal heat in a shorter time by heat conduction than water, and the first pipe 1 is formed by utilizing such heat characteristics of air. Geothermal heat is recovered in the water within a short time.
[0019]
As shown in FIG. 1 or FIG. 2, the air circulation path 7 is formed by the outward path 71 from the bottom outlet in the second pipe 2 to the top inlet of the first pipe 1 and the internal space of the first pipe 1. A first internal passage 12, a return path 72 from an end outlet of the first internal passage 12 to a top entrance of the second pipe 2, and a second internal passage 21 formed by an internal space of the second pipe 2. Contains. In the air circulation path 7, air is circulated by the function of forming the suction area V and the discharge area B exerted by the screw 5 described above.
[0020]
Therefore, only by operating the pump P interposed in the water circulation path 4, the air circulates through the air circulation path 7 without requiring another power. Then, when air passes from the suction region V to the discharge region B of the first internal passage 12, the water that is diffused as fine water droplets by the screw 5 efficiently and directly contacts the air to exchange heat. In this case, since air is a substance that easily conducts heat, it passes through the second internal passage 21 of the second pipe 2 to have a temperature substantially equal to that of geothermal heat. Therefore, the heat exchange by direct contact between the air and the diffused water in the first internal passage 12 transfers the geothermal heat recovered by the air to the water, and the water recovers the geothermal heat in a short time. Therefore, in the steam-water heat exchanger 3, the geothermal heat recovered by the water is transmitted to the outside air, and the outside air reaches a temperature at which satisfactory air conditioning can be performed.
[0021]
In particular, in this embodiment, as described above, the outer peripheral portion of the rotation locus of the screw 5 is close to the inner peripheral surface 11 of the first pipe 1, and the outer peripheral portion of the rotational locus is diffused by the screw 5 and Since it comes into contact with the water film formed by adhering to the inner peripheral surface 11, the backflow of air passing from the suction region V to the discharge region B in the first internal passage 12 is caused by the water film. In addition, since the air and the diffused water passing from the suction area V toward the discharge area B are stirred by the rotation of the screw 5, the air and the water come into direct contact with each other efficiently. . As a result, a situation occurs in which the air is entrained in the water or dissolves in the water and accumulates in the water reservoir 16 of the first pipe 1, whereby the geothermal heat recovered by the air is transmitted to the water more efficiently. Become.
[0022]
In this embodiment, both the water circulation path 4 and the air circulation path 7 are formed as closed circuits that are cut off from the outside. Therefore, dust does not enter the water circulation path 4 and the air circulation path 7 from the outside, and the paths 4 and 7 do not become narrowed or clogged due to the adhesion or accumulation of dust, thereby making maintenance easier. The operating cost can be kept low.
[0023]
In this embodiment, as the water / water heat exchanger 3, as shown in FIG. 4, a water passage 31 is formed by a helical tube, and an air passage 32 through which outside air passes is formed outside the water passage 31. The specific configuration of the heat exchanger 3 is not limited to the illustrated example.
[0024]
Further, the capacity of the first pipe 1 and the second pipe 2 should be selected in consideration of the size of the building for air conditioning, the size of the site, and the like as appropriate. For example, when air conditioning a large building of 100 tsubo or more, it is necessary to increase the capacity of the first pipe 1 accordingly, and when the building is small, the capacity of the first pipe 1 is correspondingly small. It is desired to do. When it is necessary to increase the capacity of the first pipe 1, increasing the diameter of one first pipe 1 is not preferable in terms of geothermal recovery efficiency. Therefore, for example, as shown in FIG. 5, two or a required number of the first pipes 1 are buried in parallel in the ground, and the outward path 41 and the return path 42 of the water circulation path 4 connected to each first pipe 1 and the air. The outward path 71 and the return path 72 of the circulation path 7 are connected in parallel. As described above, when the forward path 41 and the return path 42 of the water circulation path 4 connected to each of the first pipes 1 are connected in parallel, the speed of the water flow is reduced. For example, in the case of FIG. 5, since the first pipe 1 is increased by one, the water flow velocity is halved. Is reduced to one fifth, and efficient geothermal recovery can be performed accordingly. When the first pipes 1 are buried in the ground in parallel and the outgoing path 41 and the return path 42 of the water circulation path 4 connected to each first pipe 1 are connected in parallel to each other, one pipe is formed. The overall capacity of the first pipe 1 is increased while keeping the diameter of the first pipe 1 small, thereby enabling efficient geothermal recovery.
In FIG. 5, the same or corresponding elements as those described with reference to FIG.
[0025]
【The invention's effect】
As described above, according to the geothermal air-conditioning system according to the present invention, by utilizing the thermal characteristics of air, which is a substance that is more likely to conduct heat than water, the air-conditioning system is more efficient than the conventional case, and the operating cost is higher. It is possible to provide a geothermal utilization air-conditioning system capable of reducing the cost of air conditioning.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a main part of an embodiment of a geothermal air conditioning system according to the present invention.
FIG. 2 is an explanatory diagram showing a part of FIG. 1 in detail.
FIG. 3 is a horizontal sectional view when a first pipe is cut at a screw installation location.
FIG. 4 is a schematic explanatory view of a steam-water heat exchanger.
FIG. 5 is an explanatory diagram showing a main part of a geothermal air conditioning system according to a modification.
[Explanation of symbols]
P Pump for water supply 1 First pipe 2 Second pipe 3 Air / water heat exchanger 4 Water circulation path 5 Screw 7 Air circulation path 11 Inner peripheral surface of first pipe 12 First internal passage 21 Second internal passage 31 Water passage 32 air passage

Claims (3)

The water circulation path in which the water feed pump is interposed includes a first internal passage formed by an internal space of a first pipe buried underground and a water passage of an air-water heat exchanger installed on the ground. In the geothermal air conditioning system, the air that has exchanged heat with the water in the water passage while passing through the air passage of the air-water heat exchanger is used for air conditioning of the building.
Adding an air circulation path including a second internal passage formed by an internal space of a second pipe buried underground and the first internal passage;
The first internal passage is rotated by the action of water passing through the water circulation passage fed to the first internal passage, and the suction and discharge regions of the air passing through the air circulation passage to the second internal passage. A geothermal air-conditioning system, comprising a screw having a function of forming a liquid and a function of diffusing the water to make gas-liquid contact in the second internal passage. 2. The geothermal air conditioning system according to claim 1, wherein both the water circulation path and the air circulation path are formed as closed paths cut off from the outside of the paths. The outer peripheral portion of the rotation locus of the screw is close to the inner peripheral surface of the first pipe, and the outer peripheral portion of the rotational locus is formed on a water film formed by being diffused by the screw and adhering to the inner peripheral surface. The geothermal air-conditioning system according to claim 1 or 2, wherein the air-conditioning system is adapted to contact.

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