JP2011145050A - Energy supply system reusing existing cavern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an energy supply system reusing an existing cavern, without affecting a sight scene resource and an environment, while using efficiently a geothermal source at a large scale. <P>SOLUTION: A geothermal conversion means 6 is provided in one adit 4d in adit groups 4a-4f, in the existing cavern having a vertical shaft 2 excavated downwards and formed from a ground surface 3, and the plurality of adit groups 4a-4f communicated with the vertical shaft 2 and extended horizontal-directionally, and an electric power generating means 7 generates electric power by heat energy acquired by the geothermal conversion means 6. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an energy supply system that reuses an existing underground cavity.

  In a conventional geothermal power generation system, high-temperature steam is jetted to the ground surface in an area where a hot spring or the like is present, and a power generation turbine is rotated by the steam to generate power. Even when high-temperature water vapor cannot be obtained, pentane, ammonia, or the like, which is a low boiling point medium, is vaporized by geothermal heat with water vapor or the like, and a power generation turbine is rotated by the vaporized low boiling point medium to generate power.

  However, since such geothermal power generation systems are installed in areas where hot springs etc. exist, there are legal and administrative restrictions to protect tourism resources such as underground hot springs and the environment on the ground. It was impossible to realize a geothermal power generation system.

  An object of the present invention is to provide an energy supply system that reuses an existing underground cavity that does not affect tourism resources and the environment while using geothermal heat efficiently on a large scale.

  An energy supply system that reuses an existing underground cavity according to the present invention includes a vertical shaft that is formed by excavating downward from the ground surface, and a plurality of horizontal shaft groups that communicate with the vertical shaft and are located in the horizontal direction. In the existing underground cavities, the geothermal conversion means is provided in one of the horizontal pit groups, and the thermal energy acquired by the geothermal conversion means is used.

  Furthermore, the energy supply system that reuses an existing underground cavity according to the present invention is a geothermal conversion unit in which the geothermal conversion unit uses a heat medium, the low boiling point medium is vaporized by the heat medium, and the turbine of the power generation unit is installed. It is preferable to generate electricity by rotating.

  Furthermore, in the energy supply system that reuses an existing underground cavity according to the present invention, it is preferable that the power generation means is provided in another horizontal shaft group located at a shallower depth than the horizontal shaft group provided with the geothermal conversion device. .

  Furthermore, in the energy supply system that reuses an existing underground cavity according to the present invention, it is preferable that the low boiling point medium is cooled by underground spring water after rotating the turbine of the power generation means.

  Furthermore, in the energy supply system that reuses an existing underground cavity according to the present invention, the geothermal conversion means is a geothermal conversion means that uses a low boiling point medium, and the turbine of the power generation means is generated by the low boiling point medium vaporized by the geothermal conversion means. It is preferable to generate electricity by rotating.

  Furthermore, the energy supply system that reuses an existing underground cavity according to the present invention is liquefied by cooling the low boiling point medium vaporized by the geothermal conversion means at a position higher than the horizontal shaft group provided with the geothermal conversion means. Preferably, the liquefied low boiling point medium is dropped onto the geothermal conversion means, and the turbine is rotated with the low boiling point medium liquefied during the dropping of the low boiling point medium to generate electric power.

  Furthermore, in the energy supply system that reuses an existing underground cavity according to the present invention, it is preferable that the geothermal conversion means is composed of a coaxial pipe.

  Furthermore, an energy supply system that reuses an existing underground cavity according to the present invention includes a vertical shaft that is formed by excavating downward from the ground surface, and a plurality of horizontal channels that communicate with the vertical shaft and extend in the horizontal direction. In an existing underground cavity having a mine group, it is preferable to provide a geothermal conversion means planted from the vertical pit or the horizontal pit group into the ground, and use the thermal energy acquired by the geothermal conversion means.

  An energy supply system that reuses an existing underground cavity according to the present invention according to claim 1 provides a geothermal conversion means in a horizontal shaft group of the existing underground cavity, and uses thermal energy acquired by the geothermal conversion means. Therefore, a large-scale geothermal power generation system can be realized without using tourist resources such as hot springs as in the case of conventional geothermal power generation. In other words, by reusing existing underground cavities, geothermal heat can be obtained directly from the horizontal shafts of existing underground cavities, and heat exchanging means for obtaining geothermal heat is installed by reusing existing underground cavities. Therefore, it does not require the cost of constructing a new underground cavity. Furthermore, since the geothermal situation of the existing underground cavities is clear, it is not necessary to conduct a multi-point boring survey to accurately grasp the underground geothermal condition.

  The energy supply system that reuses an existing underground cavity according to the present invention described in claim 2 is a geothermal conversion unit that uses a heat medium as the geothermal conversion unit, vaporizes the low boiling point medium with the heat medium, and generates a turbine of the power generation unit. To generate electricity. Therefore, the geothermal temperature can be generated if there is a temperature higher than the boiling point of the low boiling point medium, and can be generated even when the existing underground cavity is not extremely hot.

  In the energy supply system that reuses an existing underground cavity according to the present invention according to claim 3, the power generation means is provided in another side shaft group located at a shallower depth than the side shaft group provided with the geothermal conversion means. It is characterized by. Therefore, the distance between the geothermal exchange means and the power generation means can be shortened, and the heat energy sent from the geothermal exchange means to the power generation means can be prevented from being wasted.

  An energy supply system that reuses an existing underground cavity according to the present invention described in claim 4 is characterized in that after the turbine of the power generation means is rotated, the low boiling point medium is cooled by underground spring water. Stable cooling performance can be secured by using underground spring water with a substantially constant temperature for cooling.

  The energy supply system that reuses an existing underground cavity according to the present invention described in claim 5 is a geothermal conversion means in which the geothermal conversion means uses a low boiling point medium, and the power generation means uses the low boiling point medium vaporized by the geothermal conversion means. Electricity is generated by rotating a turbine. For this reason, since the low boiling point medium is directly heated by the geothermal exchange means, it is possible to prevent wasteful loss of heat energy.

  An energy supply system that reuses an existing underground cavity according to the present invention as set forth in claim 6 is that the low boiling point medium vaporized by the geothermal conversion means is cooled at a higher position than the horizontal shaft group provided with the geothermal conversion means. The liquefied and liquefied low boiling point medium is dropped to the geothermal conversion means, and the turbine is rotated by the low boiling point medium liquefied during the dropping of the low boiling point medium to generate electric power. The potential energy can be converted into electric energy by the rise of the vaporized low boiling point medium and the fall of the liquefied low boiling point medium.

  The energy supply system that reuses an existing underground cavity according to the present invention as set forth in claim 7 is a wide range of horizontal shafts even when the horizontal shaft is submerged in warm water by configuring the geothermal conversion means as a coaxial pipe. It becomes possible to acquire geothermal energy from.

  An energy supply system that reuses an existing underground cavity according to the present invention as set forth in claim 8 communicates with the vertical shaft formed by excavating downward from the ground surface, and communicates with the vertical shaft and extends in the horizontal direction. In an existing underground cavity having a plurality of horizontal shaft groups, a geothermal conversion means planted from the vertical shaft or the horizontal shaft group into the ground is provided, and the thermal energy acquired by the geothermal conversion means is used. Therefore, the geothermal conversion means can be easily planted from the inside of the existing underground cavity, and the installation cost of the geothermal conversion means can be greatly reduced.

  Hereinafter, a first embodiment of an energy supply system that reuses an existing underground cavity according to the present invention will be described with reference to FIGS. 1 to 5. The energy supply system that reuses an existing underground cavity according to the present embodiment includes a vertical shaft 2 that is formed by excavating downward from the ground surface 3, and a plurality of horizontal channels that communicate with the vertical shaft 2 and extend in the horizontal direction. In the existing underground cavity 1 having the mine group 4, a geothermal conversion means 6 is provided in one side pit group 4d of the horizontal mine group 4, and the thermal energy acquired by the geothermal conversion means 6 is used. .

  FIG. 1 is a vertical sectional view of an existing underground cavity 1. This existing underground cavity 1 is an underground mine shaft of a coal mine that has been abandoned, and is formed by excavating downward from the surface 3 of the coal mine, and a vertical shaft 2 that communicates with the vertical shaft 2 and extends in the horizontal direction. It consists of a plurality of horizontal pit groups 4.

  In general, as shown in FIG. 1, the underground structure of a domestic coal mine has a sedimentary layer in which a coal layer B exists at the upper part and a rock layer A exists below the coal layer B. And in the excavation work of the coal mine, the side pit group 4 was excavated along the upper surface of the bedrock layer A, and coal of the coal layer B was collected. Moreover, since this bedrock layer A has a property which does not allow water to pass through easily, while coal bed B has a property which can easily pass water, it has abundant water amount in the upper part of the bedrock layer A in which this horizontal shaft group 4 is located. There are often groundwater veins. In addition, in FIG. 1, since drawing becomes complicated about sedimentary layers other than the bedrock layer A and the coal layer B, illustration is abbreviate | omitted. Reference numeral 3 denotes the ground surface.

  The vertical shaft 2 includes not only one extending in the vertical direction as shown in FIG. 1 but also one extending obliquely downward called a tilt shaft. The vertical shaft 2 is a shaft larger than the horizontal shafts constituting the horizontal shaft group 4, and an elevator for carrying in / out, a drain pipe, a blower pipe, a power transmission line and the like are left unattended.

  The plurality of horizontal shaft groups 4 are illustrated as horizontal shaft groups 4a to 4f. Each horizontal shaft group 4 exists between the bedrock A and the coal bed B, respectively, and spreads in a mesh shape as shown in FIG.

  Next, the structure of the energy supply system that reuses the existing underground cavity 1 of the first embodiment will be described. As shown in FIG. 3, in this embodiment, the geothermal exchange means 6 is installed in the horizontal shaft 4d located at a relatively deep depth. This geothermal exchange means 6 has a large number of thin tubes 6a, and these thin tubes 6a are in contact with the bottom surface, both wall surfaces, the ceiling surface and the like of the horizontal shaft 4d. And the thin tube 6a is heated by the geothermal heat in the horizontal shaft 4d, and this thermal energy is conducted to the heat medium flowing inside the thin tube 6a. In addition, the heat medium of this embodiment is water.

  As shown in FIG. 4, the geothermal exchange means 6 is connected to a supply pipe 6 b that supplies a low-temperature heat medium and a delivery pipe 6 c that sends out the heat medium heated by the geothermal exchange means 6. The supply pipe 6b is branched to the narrow pipe 6a and then connected to the delivery pipe 6c. The supply pipe 6 b and the delivery pipe 6 c pass through the inside of the vertical shaft 2 and are connected to the power generation means 7 installed on the ground surface 3. The heat medium heated by the narrow tube 6a is sent to the power generation means 7 by the delivery pipe 6c, and as will be described later, the heat medium cooled by the power generation means 7 is pressure-fed to the narrow pipe 6a by the supply pipe 6b.

  As shown in FIG. 5, the power generation means 7 is a power generation facility that generates power by a binary power generation method that is a known power generation method. This binary power generation method is a method in which a liquid having a low boiling point is heated and evaporated by a heating source, and the steam turbine is rotated by the steam. The power generation means 7 includes a heat exchanger 7a, a steam turbine 7b, a generator 7c, and a cooler 7d. By the heat exchanger 7a heated by the heat medium, pentane (pentane / boiling point is about 36 degrees) is made into steam, and the steam turbine 7b is rotated by the steam pressure of the pentane and is connected to the steam turbine 7b. Power is generated by the generator 7c. The pentane that has passed through the steam turbine 7b is cooled and liquefied by the cooler 7d. And the liquefied pentane is sent to the heat exchanger 7a. The cooler 7d is cooled by an air cooling fan (not shown) that blows the air on the ground to the cooler 7d.

  This embodiment has an advantage that a large-scale geothermal power generation system can be realized by reusing the existing underground cavity 1 without using tourist resources such as hot springs as in conventional geothermal power generation. That is, by reusing the existing underground cavity 1, geothermal heat can be obtained directly from the inner wall surface of the existing underground cavity 1, and the heat exchanging means 6 for obtaining geothermal heat is obtained from the existing underground cavity 1. Because it is reused and installed, it does not require the cost of constructing a new underground cavity.

  Furthermore, according to this embodiment, since the geothermal state at the time of use of this existing underground cavity 1 (at the time of being used as a coal mine in the case of this embodiment) is recorded in materials, the energy of this embodiment is recorded. Another advantage is that it is easy to plan the installation of the supply system. The reason why conventional geothermal power generation uses tourism resources such as hot springs and does not directly use geothermal heat as in this embodiment is because the underground geothermal state cannot be accurately grasped. In order to accurately grasp the underground geothermal condition, it is necessary to conduct a boring survey at many points, which requires a large amount of survey cost. In addition, it is difficult to carry out such boring because it may damage the groundwater veins of hot springs. However, if the existing underground cavity 1 is reused, such costs and risks can be completely avoided.

  In addition, the geothermal exchange means 6 of this embodiment can be changed into the geothermal exchange means 61 shown in FIG. 11 or the geothermal exchange means 62 shown in FIG. 12 according to the situation inside the existing underground cavity 1. The geothermal exchange means 61 shown in FIG. 11 can be installed even when it is difficult to install the narrow pipe 6a of the geothermal exchange means 6, for example, even when the horizontal shaft 4d of the existing underground cavity 1 is submerged by warm water. it can. The geothermal heat exchanging means 61 includes a coaxial pipe 61a having a double-pipe structure, a supply pipe 61b that supplies a low-temperature heat medium, and a delivery pipe 61c that sends out the heat medium heated by the geothermal heat exchanging means 61a. Yes. The heat medium circulates from the outer pipe portion of the same pipe 61a to the inner pipe portion and is heated by the heat energy of the hot water. By inserting the coaxial pipe 61a into the horizontal shaft 4d from above the hot water surface, it is possible to acquire thermal energy of a wide range of warm water inside the horizontal shaft 4d in which the coaxial pipe 61a extends. The coaxial pipe 61a is preferably a flexible resin pipe.

  Moreover, the geothermal exchange means 62 shown in FIG. 12 can acquire thermal energy from the high-temperature geotropics existing at a deeper position using the depth of the existing underground cavity 1. For example, as shown in FIG. 12, the coaxial pipe 62a of the geothermal exchange means 62 is planted into the ground from the bottom surface of the vertical shaft 2 or the horizontal shaft 4d. In this case, the installation cost can be greatly reduced as compared with the case where the coaxial pipe as the geothermal exchange means is planted from the ground surface.

  In addition, although the energy supply system of this embodiment aims at electric power generation, the thermal energy acquired by the geothermal exchange means 6 is used as a heat source necessary for agricultural facilities such as ground district heating facilities, factories, and greenhouses. It is also possible.

  Next, a second embodiment according to the present invention will be described with reference to FIGS. The present embodiment is an energy supply system that reuses an existing underground cavity 1 having the same configuration as that of the first embodiment, and the same means and structures are described using the same reference numerals as those of the first embodiment. To do.

  As shown in FIG. 6, the energy supply system that reuses the existing underground cavity 1 of the present embodiment uses a geothermal power generation unit 7 that generates power using the thermal energy acquired by the same geothermal conversion unit 6 as in the first embodiment. It differs from the system of the first embodiment in that it is provided in another horizontal shaft group 4c located at a shallower depth than the horizontal shaft group 4d provided with the conversion means 6. By providing the power generation means 7 in the basement, the distance between the geothermal exchange means 6 and the power generation means 7 can be shortened. For this reason, the extension distance of the delivery pipe 6c extended from the geothermal exchange means 6 is shortened, and in the heat energy sent from the geothermal exchange means 6 to the power generation means 7, energy that is dissipated wastefully in the delivery pipe 6c. The amount can be reduced.

  Moreover, in the said 1st Embodiment, the pentane which passed the steam turbine 7b of the electric power generation means 7 is cooled and liquefied by the cooler 7d. And this cooler 7d was cooled by the air cooling fan which ventilates the air | atmosphere on the ground to the cooler 7d. As shown in FIG. 7, in this embodiment, not the ground air but the spring water that springs from the horizontal shaft group 4c provided with the power generation means 7 or the spring water of another horizontal shaft group (for example, the horizontal shaft group 4b). To cool the cooler 7d. As described above, in the existing underground cavity 1 in the present embodiment, there are many cases where underground water veins having an abundant amount of water exist in the upper part of the rock formation A where the horizontal shaft group 4 is located. The spring water from this underground water vein is very excellent as cooling water because there is almost no change in water temperature.

  Next, a third embodiment according to the present invention will be described with reference to FIGS. The same means and structures as those in the first embodiment will be described using the same reference numerals as those in the first embodiment.

  In the energy supply system that reuses the existing underground cavity 1 of this embodiment, the heat transfer medium 6 is heated by the geothermal conversion means 6 in the first embodiment, whereas the low boiling point medium pentane or ammonia is used. It differs in that it heats etc. Since the low-boiling point medium is directly heated by the geothermal converting means 6, it is possible to simplify the equipment constituting the system.

  As shown in FIGS. 8 and 9, the energy supply system that reuses the existing underground cavity 1 of the present embodiment vaporizes the low boiling point medium by the geothermal conversion means 6, and the first power generation means by the vaporized low boiling point medium. 7 steam turbine 7b is rotated to generate electric power. In addition, the low boiling point medium that has passed through the steam turbine 7b is cooled and liquefied by the cooler 7d, and in the middle of dropping the liquefied low boiling point medium to the geothermal conversion means 6, as shown in FIG. The power generation turbine 8a is rotated to generate power.

  Also in this embodiment, the 1st electric power generation means 7 is provided on the ground similarly to the said 1st Embodiment. The low boiling point medium that has passed through the steam turbine 7b of the first power generation means 7 is cooled and liquefied by the cooler 7d. The cooler 7d cools the low boiling point medium with the coolant, while the coolant that has passed through the cooler 7d and becomes hot water is cooled by being used by a district heating system or the like, and then the cooler 7d. Reused as cooling water. The low boiling point medium cooled and liquefied by the cooler 7d falls in the supply pipe 6b passing through the inside of the shaft 2, rotates the turbine 8a of the second power generation means 8, and generates power by the generator 8b.

  In the present embodiment, as described above, since the low boiling point medium is directly heated by the geothermal conversion means 6, the equipment can be simplified, and the low boiling point medium liquefied by the second power generation means 8 is dropped. There is an advantage that energy can also be used.

  In the present embodiment, the first power generation means 7 and the second power generation means 8 are used in combination. However, the existing underground cavity 1 can be restored only by the first power generation means 7 or the second power generation means 8 alone. It functions as a used energy supply system.

1 is a vertical sectional view of an existing underground cavity 1 provided with an energy supply system that reuses an existing underground cavity according to an embodiment of the present invention. It is a horizontal sectional view of the horizontal shaft group 4 of the existing underground cavity 1 shown in FIG. 1 is a vertical sectional view of an existing underground cavity 1 showing a state in which an energy supply system that reuses an existing underground cavity according to a first embodiment of the present invention is provided. It is a conceptual explanatory drawing of the geothermal exchange means 6 of the energy supply system which reused the existing underground cavity shown in FIG. It is a conceptual explanatory drawing of the electric power generation means 7 of the energy supply system which reused the existing underground cavity shown in FIG. It is the vertical sectional view of the existing underground cavity 1 which shows the state which provided the energy supply system which reused the existing underground cavity of 2nd Embodiment which concerns on this invention. It is a conceptual explanatory drawing of the electric power generation means 7 of the energy supply system which reused the existing underground cavity shown in FIG. It is the vertical sectional view of the existing underground cavity 1 which shows the state which provided the energy supply system which reused the existing underground cavity of 3rd Embodiment which concerns on this invention. It is a conceptual explanatory drawing of the 1st electric power generation means 7 of the energy supply system which reused the existing underground cavity shown in FIG. It is a conceptual explanatory drawing of the 2nd electric power generation means 8 of the energy supply system which reused the existing underground cavity shown in FIG. It is a conceptual explanatory drawing of the geothermal exchange means 61 of the energy supply system which reused the existing underground cavity shown in FIG. It is a conceptual explanatory drawing of the geothermal exchange means 62 of the energy supply system which reused the existing underground cavity shown in FIG.

DESCRIPTION OF SYMBOLS 1 Existing underground cavity 2 Vertical shaft 3 Ground surface 4, 4a, 4b, 4c, 4d, 4e, 4f Horizontal shaft group 6, 61, 62 Geothermal conversion means 6a Narrow tube 61a Resin coaxial pipe 62a Coaxial pipe 6b, 61b, 62b Supply Pipe 6c, 61c, 62c Delivery pipe 7 Power generation means, first power generation means 7a Heat exchanger 7b Steam turbine 7c Generator 7d Cooler 8 Second power generation means 8a Power generation turbine 8b Generator A Rock bed layer B Coal bed

Claims (8)

A shaft formed by drilling downward from the ground surface;
In the existing underground cavity having a plurality of horizontal shaft groups communicating with the vertical shaft and extending in the horizontal direction,
Geothermal conversion means is provided in one horizontal shaft group of the horizontal shaft group,
An energy supply system that reuses an existing underground cavity, characterized by using thermal energy acquired by the geothermal conversion means. The existing underground heat generation means according to claim 1, wherein the geothermal conversion means is a geothermal conversion means using a heat medium, and generates electric power by vaporizing a low boiling point medium by the heat medium and rotating a turbine of the power generation means. Energy supply system that reuses cavities. 3. The energy supply system for reusing an existing underground cavity according to claim 2, wherein the power generation means is provided in another horizontal shaft group located at a shallower depth than the horizontal shaft group provided with the geothermal conversion means. . 4. The energy supply system that reuses an existing underground cavity according to claim 3, wherein after the turbine of the power generation means is rotated, the low boiling point medium is cooled by underground spring water. 2. The existing underground heat generator according to claim 1, wherein the geothermal conversion means is a geothermal conversion means using a low boiling point medium, and generates electricity by rotating a turbine of the power generation means by the low boiling point medium vaporized by the geothermal conversion means. Energy supply system that reuses cavities. The low boiling point medium vaporized by the geothermal conversion means is liquefied by cooling at a position higher than the horizontal shaft group provided with the geothermal conversion means, and the liquefied low boiling point medium is dropped to the geothermal conversion means, and the low boiling point is reduced. 2. The energy supply system that reuses an existing underground cavity according to claim 1, wherein a power is generated by rotating a turbine with a low boiling point medium liquefied in the middle of dropping of the medium. The said geothermal conversion means is an energy supply system which reused the existing underground cavity of Claim 1 comprised from the coaxial pipe | tube. A shaft formed by drilling downward from the ground surface;
In the existing underground cavity having a plurality of horizontal shaft groups communicating with the vertical shaft and extending in the horizontal direction,
Provide geothermal conversion means planted into the ground from the vertical shaft or the horizontal shaft group,
An energy supply system that reuses an existing underground cavity, characterized by using thermal energy acquired by the geothermal conversion means.

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