JP2013032764A - Method and apparatus for obtaining steam by injecting water into underground heat source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for obtaining steam for geothermal power generation without limitation of site location and without causing an unusual state in underground pressure, water veins, water volume or the like and losing a balance of the underground structure.SOLUTION: Through a water injection pipe 1 and a steam discharge pipe 2 installed together with the water injection pipe toward an underground heat source at a depth of about 200 m or more, underground water source or rain water is used to be injected into the water injection pipe to obtain steam through the steam discharge pipe and the obtained steam is used for power generation. Thereby performing the connection and utilization according to the purpose of the other existing apparatuses, devices or the like. The steam discharge pipe has a diameter of about 100 m/m or more and a water reservoir 5 is provided at a bottom near an underground heat source 4. Water injected through the water injection pipe flows into the water reservoir via a damper valve 3 that is set to sink or float, and remains in a given amount at the bottom.

Description

  Today, where diversification of power generation methods is required, geothermal power generation is attracting attention as one of them. However, the geothermal power generation method that has been considered so far involves digging a hole toward a hot spring source, collecting steam, hot water, etc., and moving the turbine to generate electricity. However, with this method, the location is limited to hot springs and the like, and the collection of large-scale steam and hot springs may cause changes in underground pressure, water veins, water volume, etc., and may disrupt the balance of the underground structure.

Geothermal recovery methods include the method of using the hot water and steam as they are jetted, the method of exchanging heat from hot water to a fluid with a low boiling point, and the method of pouring water into the basement and changing it to steam by geothermal heat. Yes. Geothermal heat is attracting attention as the next generation of clean energy because it provides a stable supply throughout the year without producing carbon dioxide, and research is currently underway on its efficient use.
There is also a method (ground heat) that uses the temperature difference between the ground temperature and the underground temperature. In this case, the underground temperature does not have to be particularly high, and can be used anywhere.

Geothermal power generation is to generate electricity by turning a turbine / generator using steam or hot water that is spouted from the ground or injected from the ground. In addition, even when the underground temperature and pressure are low and only hot water can be obtained, there is also a method in which a medium having a lower boiling point than water such as ammonia, pentane, and chlorofluorocarbon is boiled with hot water and a turbine is rotated to generate electricity. It is one of the clean energy that does not use fossil fuels such as oil.
As a geothermal source, the source of geothermal heat is the center of the earth. The inside of the earth is divided into the crust of solid rock, the mantle of solid rock, the outer shell made of molten metal mainly composed of iron and nickel, and the inner shell composed of solid metal mainly composed of iron and nickel. Yes.
● Most of the heat generated within the earth is derived from the heat generated when natural radioactive elements decay.
45 to 85 percent of geothermal heat comes from radioactive decay of elements contained in the crust.
● The heat of shock and compression as the fallen meteorite is taken into the original Earth structure.
● Frictional heat released when excess heavy metals (iron, nickel, copper) sink to the earth's core.
● Joule heat generated by the electromagnetic effect produced by geomagnetism.
The amount of heat generated at the Earth's core is estimated to be in the range of 4-10 terawatts. This geothermal heat reaches near the surface of the earth and reaches the geotropics of 200-300 ° C if it is dug about 1 km from the surface. It reaches the tropics in this shallow area at 200-500m.

As an advantage of geothermal power generation,
The amount of carbon dioxide emitted is small (the amount of carbon dioxide emitted per unit power generation is about 1/20 that of thermal power generation).
There is no need for fuel, and there is little concern about fuel depletion or soaring.
The output is more stable than other new energy generation.
Stable power generation can be obtained according to demand.

The disadvantages of geothermal power generation are:
Exploration / development is very expensive and time consuming.
Development risk is high (unknown until you dig)
There are noise and vibration due to boring work under construction, and noise of fumarole.
There is a possibility of land subsidence and soil contamination due to hot water and steam sampling.
There is air pollution due to the release of hydrogen sulfide.
This may affect existing geothermal facilities such as mud water entering and hot spring decay.
Japan's geothermal field is not easily developed because there are many areas where development is regulated in national parks.

As for the current situation of geothermal power generation,
The current power generation cost is 21 yen / kWh (15 yen / kWh for subsidies).
The amount of power generation in Japan is 3,369 x 106 kWh (0.2% of domestic power generation capacity)
However, when all unused resources exceeding 20 million kilowatts in terms of power generation output are used, a large amount of hot water that cannot be used for steam power generation, which is estimated to be equivalent to 15 nuclear power plants, In many municipalities where geothermal power plants are located, in order to make effective use of the energy of this hot water, heat is exchanged with river water, and the generated hot water is produced and supplied to nearby areas for use in regional development. It can be said that this is one of the forms of using renewable energy.
[Literature] Japanese Patent Laid-Open No. 2001-355566 (JP, A) [Reference] Wikipedia Free Encyclopedia Geothermal

For the future of geothermal power generation,
・ Development of deep geothermal resource extraction technology (Currently, development of deep geothermal resources (depth 3,000-4,000m, temperature around 350 ° C) is desired to increase geothermal power generation capacity. (It is assumed that it is in a hard geological environment with higher temperature and pressure than resources)
・ Development of high-temperature rock power generation → To put it simply, we will develop and investigate a method of generating electricity by collecting steam and hot water by circulating water from the ground surface in a high-temperature rock body that does not contain water from the ground. The challenge is to develop technology that can be performed reliably and in a short time, to investigate and develop new areas, and to establish laws for geothermal power generation in areas such as national parks.
In addition, the amount of power generation is insignificant in terms of power consumption in Japan, but the output is stable compared to other new energies and the supply can be adjusted, so it can spread as a stable output source. The nature seems to be high.

  Therefore, a hole is dug to the vicinity of the underground heat source, this pipe system is laid down, water is poured into this hole from the ground, and the water is collected from the steam collection port of the pipe and used for power generation, heating, etc. This is what you are trying to do.

Steam is inserted into the ground through a steam collection port attached to the water injection pipe by inserting a pipe toward the underground heat source at a depth of about 200 meters or more and injecting water into the ground using a river, groundwater source or rainwater. To obtain the method and equipment.
The diameter of the steam collecting pipe is set to about 100 m / m or more, and a water reservoir is provided at the bottom near the heat source in the ground, so that a fixed amount of water injected from the water injection pipe stays at the bottom so that it floats and sinks. It flows into the water reservoir through a damper bend. The obtained steam is connected and utilized according to the purpose of power generation and other existing devices and equipment.

  Japan is a volcanic country, and at about 500 meters underground, it has a heat of 200 ° C or above in most areas, making it easy to get a location. In addition, since only the heat source by water injection is used, there is no underground modulation and the balance is not lost. There is no air pollution caused by the release of hydrogen sulfide. Furthermore, it can be said that development risk is low and small-scale decentralized locations are possible.

A steam collecting pipe that is connected to the underground water injection pipe by inserting a pipe into the underground heat source at a depth of about 200 meters or more and injecting water into it using rivers, groundwater sources, or rainwater. The present invention relates to a method and apparatus for obtaining steam through.
The diameter of the steam release pipe is about 100 m / m or more, and a water reservoir is provided at the bottom near the heat source in the ground, so that a certain amount of water injected from the water injection pipe stays at the bottom so that it floats and sinks. It flows into the water reservoir through a damper bend. The obtained steam is connected and utilized according to the purpose of power generation and other existing devices and equipment.
The damper bend is movable up and down, thereby replacing the water pressure problem with the relationship between the water pressure of the water injection pipe and the weight balance between the reservoir and the damper bend. Depending on the depth of the underground, the weight and water pressure at the bottom of the injected water will be different, so change the weight setting of the damper bend accordingly.

Steam inserted in the ground with the water injection pipe 1 by inserting the water injection pipe 1 toward the underground heat source with a depth of about 200 meters or more and injecting water into the ground using a river, groundwater source or rainwater. The invention relates to a method and an apparatus for obtaining steam 8 through a collecting pipe 2.
The diameter of the steam release pipe 2 is set to about 100 m / m or more, and a water reservoir 5 is provided at the bottom near the underground heat source, and the water 6 injected from the water injection pipe 1 floats and sinks in order to retain a certain amount at the bottom. It flows into the water reservoir 5 through the damper bend 3 set as described above. The obtained steam is connected and utilized according to the purpose of power generation and other existing devices and equipment.
FIG. 1 is a view of water injection.
The bottom water pressure of the injection water 6 varies depending on the depth. Therefore, the amount of water in the damper ben 3 and the water reservoir 5 is adjusted. That is,
Injected water weight = Damper ben weight + Water in the water reservoir The water in the water reservoir 5 is heated by geothermal heat and decreases to become steam 8.
The weight of injected water> the weight of the damper ben + the weight of the water in the water reservoir, the damper ben 3 rises and water injection 6 is started.
FIG. 2 is a diagram when water injection is stopped. When the amount of water in the reservoir 5 increases due to the injected water 6, the weight of injected water becomes less than the weight of the damper bend + the water in the reservoir, and water injection stops.
The steam 8 is continuously generated regardless of whether the water is being poured or stopped. The damper bend is movable up and down, and the water pressure adjusting unit 12 provided at the lowermost part replaces the problem of water pressure with the relationship between the water pressure of the water injection pipe and the weight balance of the water reservoir including the damper bend. For example, an iron damper (specific gravity 7.8) damper ben must have a thickness of about 30 cm in order to secure a water reservoir of about 10 m. Provide appropriate clearance between pipes.

● Hot springs are a traditional method of using geothermal heat. In addition to warming people (for bathing), hot springs boil eggs (hot spring eggs) and vegetables, and steam in a hell kettle that uses steam heat. ing. You can do it in a relatively small space at home or at work.
● Geothermal power generation: It can be done at home and at work.
● Heating: Hot spring steam is used for room heating in old hot springs.
● Horticulture: In flower gardening, vegetables and flowers can be cultivated and bred using hot spring heat.
● Other applications include cooling, aquaculture, snow melting, food and wood processing.
Although not shown in the drawings, as another embodiment of this principle, the pipe portion in FIG. 2 is shortened so that the sump portion has a large diameter and the whole is set on the ground, and this sump portion is made of gas or heavy oil. It can be heated and used as a steam generating boiler.

It is a figure when water injection is stopped. When the amount of water in the water reservoir 5 increases due to the water injection 6, the water injection stops. Steam is continuously generated regardless of whether water is being poured or stopped. FIG. The bottom water pressure of the injection water 6 varies depending on the depth. Accordingly, the amount of water in the damper ben 3 and the water reservoir 5 is adjusted. Since the water in the water reservoir 5 is heated by geothermal heat and decreases to become steam 8, the damper ben 3 rises and water injection is started. As shown to AA sectional drawing and BB sectional drawing, a water inlet is provided so that a center may correspond to a center part, and a some water inlet is arrange | positioned around that position.

DESCRIPTION OF SYMBOLS 1 Water injection pipe 2 Steam vent pipe 3 Damper ben 4 Underground heat source 5 Water reservoir 6 Injection water 7 Water 8 Steam 9 Surface 10 Steam collection port 11 Bottom water injection plate (fixed) 12 Water pressure adjustment part

Claims (3)

  By inserting a water injection pipe toward the underground heat source at a depth of about 200 meters or more and injecting water using a river, a groundwater source, or rainwater, the steam is acquired through the steam collection pipe attached to it. Method and apparatus.   The diameter of the steam collecting pipe is about 100 m / m or more, a water reservoir is provided at the bottom near the underground heat source, and water is injected through a damper bend that is set so that water injected from the water injection pipe floats and sinks to the bottom. The method and apparatus for obtaining steam according to claim 1, wherein the amount of water flowing into the reservoir is adjusted.   3. The method and apparatus for acquiring steam according to claim 1 or 2, characterized in that the acquired steam is connected and utilized in accordance with the purpose of power generation and other existing devices and equipment.

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