JP2018179322A - Geothermal energy utilizing facility and geothermal energy utilizing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a geothermal energy utilizing technique which is suitable for utilizing on a land of high geothermal energy and which is used by heating a liquid.SOLUTION: A geothermal energy utilizing facility includes: a bottom-closed outside tube which is buried in a dug ground of high geothermal energy; an intermediate tube stored in the outside tube, defining an annular heating flow passage having a predefined thickness between the outside tube, and having a function of heating the utilized liquid which moves in the annular heating flow passage from up to down; a liquid inlet into which the utilized liquid is injected from upside into the annular heating flow passage; a liquid-pumping tube provided in the intermediate tube and pumping the heating liquid from down to up; a heated liquid utilizing facility for utilizing the heated liquid; a liquid transferring tube for connecting the liquid-pumping tube to the heated liquid utilizing facility; and a collection tube for connecting the heated liquid utilizing facility to the outside tube and circulating to utilize the liquid utilized in the heated liquid utilizing facility by reflowing the liquid in the annular heating flow passage.SELECTED DRAWING: Figure 1-2

Description

  The present invention relates to geothermal technology that is applied to areas with high geothermal energy such as hot spring resorts.

  BACKGROUND ART Conventionally, techniques for using snow water and cooling are known. However, pumping up groundwater causes land subsidence and disturbance of the groundwater system. In hot spring areas, hot water with high temperature is accompanied by a right, and the use of persons other than the right holder is restricted.

  Insert the double pipe with the open inner pipe at the bottom into the closed outer pipe at the bottom, insert water into the ground, supply the water between the outer pipe and the inner pipe, and It has been proposed that the heat exchange be performed between the two, and the water subjected to the heat exchange be sent from the lower part to the upper part of the inner pipe and used outside (for example, Patent Document 1).

  It is explained that cold water can be used as winter water temperature for snow removal, heating, etc. in winter and warm water can be used as cooling water for underground water temperature in summer without causing any obstacles due to groundwater pumping. ing.

Japanese Patent Application Laid-Open No. 57-187557

  We will provide geothermal utilization technology that uses liquid that is suitable for high geothermal areas such as hot spring areas and using equipment that has been excavated and embedded in high geothermal areas.

According to an embodiment of the present invention
A bottom closed outer pipe section with drilling and embedding in a high geothermal area,
An annular heating channel, which is accommodated in the outer pipe section and has a predetermined thickness with the outer pipe section, is defined, and the utilization liquid moving downward from above in the annular heating channel is heated by geothermal heat An intermediate pipe section with a function,
A liquid inlet for injecting a use liquid from above into the annular heating channel;
A liquid pumping pipe disposed in the intermediate pipe and pumping the heated liquid upward from below;
Heating liquid utilization equipment using heated liquid,
A liquid feed pipe portion connecting the liquid feed pipe portion to the heating liquid utilization facility;
A recovery pipe that connects the heating liquid utilization facility and the outer pipe portion, and circulates the liquid utilized in the heating liquid utilization facility to the annular heating flow path;
Geothermal utilization facilities are provided.

  The outer tube is heated by the geothermal heat to the outer surface. By setting the thickness of the annular heating channel between the outer tube portion and the intermediate tube portion for defining the channel within a predetermined thickness range, the liquid in the annular heating channel can be efficiently heated. The heated liquid is supplied to the heating liquid utilization facility through the liquid feeding pipe through the liquid feeding pipe. Only heat from the geothermal source can heat the liquid and use the heated liquid.

as well as 1A to 1C are diagrams showing a geothermal utilization facility according to Example 1, and FIG. 1A is a schematic cross-sectional view showing a state in which a well is excavated in a land having geothermal heat and an outer pipe of a heating mechanism is embedded; Inside, a schematic cross-sectional view showing how to arrange an intermediate pipe and a pumping pipe, and FIG. 1C is a schematic perspective view showing a configuration for connecting a water pipe to a heating mechanism and using it for heating a building. FIG. 2 is a schematic cross-sectional view showing the configuration of a geothermal energy utilization facility according to a second embodiment. FIG. 3A is a schematic side view showing a modification of the outer pipe, and FIG. 3B is a schematic drawing showing a modification in which a pump in the heating mechanism is connected to a liquid addition device.

1 outer pipe, 2 injection pipe, 3 middle pipe, 5 annular heating channel,
6 pumping pipes, 7 water pipes, 8 pumps, 10 wells,
11 1st flange, 13 2nd flange, 14 air vent valve, 15 heating mechanism, 16, 17, 18 heating equipment, 19 check valve, 20 gravel etc, 22 2nd water injection pipe, 23 2nd water pumping pipe,
24 water pipes, 26 injection pipes, 27 spiral heating pipes,
28 supply pipe, 31 heat absorption mechanism, 32 fluidizer.

In areas where geothermal heat is high, such as hot spring areas, it is possible to expose a formation having geothermal heat of about 50 ° C. or more by digging a certain deep hole. If such a formation is exposed and heat is absorbed by a liquid such as water, various uses will be possible. The present invention is directed to liquid heating technology utilizing geothermal energy.

  Digging a well in a geothermal area (high) and embedding a non-porous pipe (a pipe with a closed bottom and a side) as an outer pipe to form a device for heating the liquid which is a heat transfer medium using the geothermal heat think of. The liquid is typically water, but other liquids such as antifreeze may also be used. Hereinafter, the case where water is used as the liquid will be described.

Embed a double-pipe structure in the ground with high ground temperature, supply the water to be heated from the outside to the space between the outer pipe and the inner pipe, and heat it by flowing along the side of the high-temperature outer pipe, Consider a configuration in which heated water is pumped through the inner pipe.
The flow rate of water to be heated can be estimated from the target heating water utilization amount. However, when the double pipe structure is designed only for the purpose of flowing this amount of water, the distance between the outer pipe and the inner pipe (the width of the heating space) which becomes the heating space of water becomes too large. It may be too small and may be unsuitable for efficient heating.
In order to perform efficient heating, it is preferable to limit the width (thickness) of the heating space. For example, it is conceivable to accommodate a bottom open casing with a diameter (φ) of about 200 mm inside an outer casing with a diameter (φ) of 400 mm to 500 mm, and to form an annular heating space with a thickness of 100 mm to 150 mm. The thickness of the annular heating space is preferably selected in the range of 10 mm to 160 mm in consideration of depth, flow rate, and the like.

For example, a well of 50 m to 100 m in depth is dug, and if the temperature is measured by measuring geothermal heat, the well is further dug deeper so that a sufficient heating temperature can be obtained. After reaching the ground having the desired temperature, drilling of the well is terminated.
A pipe with a diameter (φ) of 200 mm is too thick as a water pumping pipe and a water pipe for sending heated water to a facility using water. For example, a tube with a diameter (φ) of 40 mm to 100 mm is sufficient, and this diameter is preferable from the viewpoint of the water pump.

Example 1
Please refer to FIG. 1A. The well 10 having a depth of about 50 m, for example, is dug from the ground surface GR, and the temperature of the ground is measured. If the temperature is insufficient, dig the well further. After reaching the ground having the desired temperature, the drilling of the well is finished. For example, it accommodates a non-porous pipe (a pipe whose bottom and side are closed) which is an outer pipe 1 having a diameter (φ) of 400 mm to 500 mm, and embeds a space around the outer pipe 1 with gravel 20 or the like. The outer pipe 1 has a function of transferring the geothermal heat of the formation to water (heat medium). It is preferable to form it with high thermal conductivity such as stainless steel and sufficient mechanical strength.

  Please refer to FIG. 1B. For example, an intermediate pipe 3 having a diameter (φ) of about 200 mm is accommodated in the outer pipe 1, and an annular heating channel having a predetermined thickness (for example, 100 mm to 150 mm) between the outer pipe 1 and the intermediate pipe 3 as a double pipe structure. Configure 5 A pumping pipe 6 extending inside the intermediate pipe 3 is disposed. Although the case where middle tube 3 is constituted while the bottom part is opened is shown, it may have a bottom surface connected to the side of pumping tube 6.

  Please refer to FIG. 1C. The water pipe 7 is formed to penetrate the middle pipe 3 and the upper side wall of the outer pipe 1 and is connected to the upper end of the pumping pipe 6. High heat conductivity is not required for the intermediate pipe 3 and the pumping pipe 6. Materials suitable for machining, strength, etc. can be selected.

  An inlet 2 for injecting water into the upper side wall of the outer pipe 1 is provided by welding, machining or the like. The first flange 11 is connected to the upper end of the outer pipe 1 by welding, machining or the like. The second flange 13 connectable to the first flange is connected to the upper end of the intermediate pipe 3 by welding machining or the like. A bolt-nut structure or the like for connecting the first flange 11 and the second flange 13 is provided. When the water surface rises from the bottom, the second flange 13 is provided with an air vent valve 14 for removing air in the middle pipe 3 and the inside of the outer pipe 1. The heating mechanism 15 is formed with such a structure.

  The water pipe 7 connected to the pumping pipe 6 is extended to the heating water utilization facility and connected to the water injection port 2 through the pump 8. The heated water sent into the water supply pipe 7 is supplied with water via the heated water utilization facility, returned from the water injection port 2 into the heating device 15, and reheated. A plurality of heating devices 16, 17, 18 are connected in parallel to the water pipe 7 to supply heating. When the heating device is turned off, the heated water does not pass through the heating device and passes only through the water pipe 7. A check valve 19 may be provided in the water supply pipe 7 to prevent reverse flow.

Example 2
Please refer to FIG. In Example 1, a single water channel using heating water as a heat source was formed. There are various applications that utilize heated water itself. In the second embodiment, in addition to the water channel using heating water as a heat source as in the first embodiment, two types of water channels using heating water itself are formed.

  The outer pipe 1, the intermediate pipe 3 and the pumping pipe 6 are substantially the same as in Example 1, but the intermediate pipe 3 has a closed bottom, and the pumping pipe 6 penetrates the bottom surface of the intermediate pipe 3. The configuration around the water pipe 7 through which the heated water flows is the same as in the first embodiment.

  It is connected to the downstream side of the second water injection pipe 22 which penetrates the second flange 13 and injects water into the intermediate pipe 3, the second water pumping pipe 23 disposed in the intermediate pipe 3, and the second water pumping pipe 23. The feed water pipe 24 constitutes a second water channel. If water is stored in the intermediate pipe 3 to a position higher than the water supply pipe 24, heated water can be supplied from the water supply pipe 24. Of course, a pump can be provided in the second water channel. When the (heated) water is used via the water supply pipe 24 and the second pumping water pipe 23, the water in the intermediate pipe 3 moves downward. The middle pipe 3 is heated at its side walls by the heated water in the annular heating channel 5, and the water in the middle pipe 3 is heated while moving downward. For example, when the second water channel is flushed with miscellaneous water, warmed miscellaneous water can be supplied.

  The spiral heating pipe 27 spirally wound on the outer side of the intermediate pipe 3 is connected to the inlet pipe 26 on the upstream side and connected to the supply pipe 28 on the downstream side to constitute a third flow path. The helical portion is disposed in the annular heating channel 5 and is heated by the water in the annular heating channel 5. Since the flow path length is extended by the helical shape wound around the outside of the intermediate pipe 3, it is possible to perform sufficient heat exchange. In addition, the channel diameter is small, and it can also be used as a gas channel. For example, when the third injection pipe 26 is connected to the water supply, the heated water can be supplied from the second supply pipe 28. The third flow path can also be used for water supply to the boiler. It is also possible to heat the air and use it for heating.

  The second embodiment is characterized in that a plurality of heating channels are formed, and plural systems of water or gas can be heated simultaneously. The application of the heating water mentioned above is an illustration and is not restrictive. For example, the channel may be a third channel, and the applications of the second channel and the third channel may be exchanged. Heated water can also be used for other applications.

  FIG. 3 shows a modification. FIG. 3A shows a structure in which a heat absorption mechanism 31 is provided around the outer tube 1. Although a fin-like endothermic mechanism is shown, the shape is not particularly limited as long as geothermal can be efficiently transmitted to water.

  FIG. 3B shows a configuration in which the pump 8 connected to the water supply pipe 7 is provided with the liquid addition device 32 and capable of replenishing the required liquid when the liquid (water) runs short.

  As mentioned above, although the case where the liquid to heat was water was explained, it is also possible to heat other liquids, such as antifreeze. Although the invention has been described along the examples, these are not limiting. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

Claims (10)

A bottom closed outer pipe section with drilling and embedding in a high geothermal area,
An annular heating channel, which is accommodated in the outer pipe section and has a predetermined thickness with the outer pipe section, is defined, and the utilization liquid moving downward from above in the annular heating channel is heated by geothermal heat An intermediate pipe section with a function,
A liquid inlet for injecting a use liquid from above into the annular heating channel;
A liquid pumping pipe disposed in the intermediate pipe and pumping the heated liquid upward from below;
Heating liquid utilization equipment using heated liquid,
A liquid feed pipe portion connecting the liquid feed pipe portion to the heating liquid utilization facility;
A recovery pipe that connects the heating liquid utilization facility and the outer pipe portion, and circulates the liquid utilized in the heating liquid utilization facility to the annular heating flow path;
Geothermal utilization equipment including.   The geothermal utilization installation according to claim 1, wherein the heating liquid utilization installation is a facility that performs heating. The bottom of the intermediate pipe portion is closed,
The geothermal utilization installation of Claim 1 or 2 which has a structure by which the said pumping pipe part penetrated the bottom part of the said intermediate pipe part, and the bottom part was released toward the said annular heating flow path. A second injection port for injecting a second use liquid from above into the intermediate pipe portion;
A second fluid pumping tube disposed in the intermediate tube and pumping the heated liquid in the intermediate tube upward from below;
A flow passage disposed in the annular heating flow passage and configured to wind the intermediate pipe portion and heating the fluid;
The geothermal utilization installation according to claim 3, further comprising   The geothermal utilization installation of Claim 4 whose said 2nd utilization liquid and the said fluid are water used in the heated state.   The outer pipe portion and the intermediate pipe portion have a cylindrical shape along the same straight linear axis, and the predetermined thickness of the annular heating channel is in the range of 10 mm to 160 mm. Geothermal utilization equipment described in 1 above. An annular heating channel having a predetermined thickness is provided between the bottom-closed outer pipe embedded in the ground having geothermal heat and the middle pipe defining the flow path contained in the outer pipe. Heating to a predetermined temperature by flowing a liquid from above to below the annular heating channel;
The heated liquid is transferred to the heating liquid utilization facility via a liquid pumping pipe disposed in the intermediate pipe for defining the flow path.
Geothermal utilization method.   8. The method according to claim 7, wherein the bottom of the middle pipe is closed, and the pumping pipe has a bottom which penetrates the bottom of the middle pipe and is released into the outer pipe. A second injection port for injecting a second use liquid from above into the intermediate pipe portion;
A second fluid pumping tube disposed in the intermediate tube and pumping the heated liquid in the intermediate tube upward from below;
A flow passage disposed in the annular heating flow passage and configured to wind the intermediate pipe portion and heating the fluid;
Further include
The geothermal utilization method of Claim 8 which heats and utilizes a 2nd utilization liquid and fluid further.   The geothermal utilization method according to any one of claims 7 to 9, wherein the predetermined thickness of the annular heating channel is in the range of 10 mm to 160 mm.

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