JPH0526953B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention sequentially guides geothermal fluid to a plurality of thermal energy utilization facilities according to the thermal energy it has, operates each thermal energy utilization facility, and performs an integrated system. This relates to a geothermal utilization system that makes effective use of geothermal energy possible.

[Conventional technology]

Geothermal energy is a natural energy source, and the amount of its resources is quite large compared to solar heat, wind power, etc., and as a new energy that is produced domestically and will not run out, it is one of the energies that is highly expected to be used effectively. be. Currently, most of the uses of geothermal energy are for power generation. Although several geothermal power plants have started operation so far, the geothermal fluid that is mainly used is dry steam, which is physically of good quality and has a temperature of 150°C or higher and has almost no moisture. In addition, depending on the chemical properties such as temperature and acidity of geothermal fluids, geothermal fluids can be used for various purposes such as agriculture, heating, snow melting, etc., although only to a small extent. Conventionally, when the thermal energy of a geothermal fluid is used for power generation and when it is used for purposes other than power generation is classified based on the temperature of the geothermal fluid in an underground reservoir.

[Problem that the invention seeks to solve]

Geothermal fluids are not necessarily stored underground in layers like oil, but are often accumulated in porous geological formations or in the cracks of many rocks. Geothermal energy reserves are expressed by the temperature of the fluid in this reservoir and the amount of thermal energy it holds, and how it is used is determined by whether the fluid is steam or hot water. On the other hand, the amount of resources from which physically high-quality steam such as dry steam can be obtained is
It is thought to account for approximately 10% of all geothermal resources. Also,
The flow rate, that is, the production volume, of geothermal fluid flowing out of a geothermal production well every hour varies significantly from well to well, and the thermal energy contained in a unit weight of geothermal fluid varies depending on the weight of steam contained in the unit weight.

As mentioned above, there are various restrictions when using geothermal fluids depending on the usage method and the content of the obtained geothermal fluid, and it is difficult to ensure consistency. That is, even if a search is made for a reservoir layer for use in power generation, for example, if the found reservoir layer does not fit the usage method, then those reservoir layers will not be used. Therefore, there are many cases in which only the production wells that produce geothermal fluid suitable for the purpose of use are secured, and other production wells are destroyed.

The present invention is based on the above considerations, and includes:
The objective is to provide a geothermal utilization system that can obtain high utilization efficiency by utilizing geothermal fluid extracted from all production wells and comprehensively utilizing the thermal energy possessed by the geothermal fluid according to its content. .

[Means for solving problems]

To this end, the utilization system of the present invention is a geothermal utilization system that utilizes the thermal energy of geothermal fluid produced from geothermal production wells, including geothermal direct power generation equipment that directly generates electricity using high-temperature geothermal fluid, and Equipped with indirect power generation equipment that exchanges heat with medium-temperature geothermal fluid as a medium to generate electricity, refrigeration equipment that cools water by absorption freezing using medium-temperature geothermal fluid as a heat source, and hot spring and other hot water utilization equipment. The geothermal fluid produced is supplied to one of the above facilities according to its temperature to utilize thermal energy, and the utilized geothermal fluid is then sequentially supplied to equipment on the low temperature side to utilize thermal energy up to hot water utilization equipment. It is characterized by being connected in such a way that it can be used effectively.

[Effect]

In the geothermal utilization system of the present invention, geothermal fluid with high thermal energy is used to first generate electricity using geothermal direct power generation equipment, and when the temperature of the geothermal fluid reaches a medium temperature, power is generated using indirect power generation equipment that uses a low-temperature medium. , and the water used for cooling and cooling is further cooled by refrigeration equipment. Once the water has reached a low temperature, this hot water is used for hot springs, heating, etc. Therefore, geothermal fluid extracted from production wells is used several times in the process, including power generation and refrigeration, before being used as hot water, and thermal energy is efficiently recovered and used without being wasted. .

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining one embodiment of the geothermal utilization system according to the present invention, in which 11 and 16 are hydrothermal energy integration sections, 12 is a direct power generation facility, and 13 is a diagram for explaining one embodiment of the geothermal utilization system according to the present invention.
14 indicates indirect power generation equipment, 14 indicates refrigeration equipment, and 15 indicates hot water utilization equipment. Hydrothermal energy integration section 11 and 16
The system extracts hot water energy in an integrated manner so that the hot water energy extracted from multiple geothermal production wells can be used collectively and effectively. The direct power generation equipment 12 is equipment that directly drives a turbine using geothermal fluid to generate electricity, and uses conventionally employed equipment such as steam power generation, flash power generation, and total flow power generation. These are selected depending on the content of the geothermal fluid extracted from the hydrothermal energy integration unit 11, and a plurality of them may be installed together. Furthermore, as mentioned above, conventional power generation has only been carried out using steam at 150°C or higher, but the direct power generation equipment 12 according to the present invention uses an atmospheric pressure turbine that uses saturated steam at 100°C as input energy. By using it, the heat energy is used to generate electricity until the temperature drops to the level used by the indirect power generation equipment 13 in the next stage. The indirect power generation equipment 13 uses carbon dioxide as a medium and drives a turbine by raising the temperature and pressure of carbon dioxide to 65°C and 130 kg/cm ² through indirect contact with medium-temperature geothermal fluid of 50 to 80°C. . The refrigeration equipment 14, like the indirect power generation equipment 13, performs cooling and freezing using the absorption refrigerant method using medium-temperature geothermal fluid.
The hot water utilization equipment 15 utilizes low-temperature hot water whose temperature has been lowered by being used in the indirect power generation equipment 13 and the refrigeration equipment 14, and is a hot spring, heating equipment, or the like.
Furthermore, geothermal fluids may be broadly classified according to the thermal energy they possess, and geothermal fluids at medium and low temperatures may be merged from the middle of the system through the integration section 16 as shown.

Next, specific examples of each equipment and transport system shown in FIG. 1 will be described.

FIG. 2 is a diagram showing the configuration of an embodiment of the hydrothermal energy integration section and direct power generation equipment according to the present invention, and FIG. 3 is a diagram for explaining an ejector used in the hydrothermal energy integration section of FIG. 2. It is. In the figure, 2
1, 22 and 23 are production wells, 24 is a silencer, 2
5 and 26 are ejectors, 27 is a steam separator, 2
8 is a steam transport pipe, 29 is a turbine, 30 is a generator, 31 is a pump, 32 is an injection condenser, 33 is a hot water tank, and 34 is a nozzle. Multiple production wells 21,
Numerals 22 and 23 are production wells that generate high-pressure, intermediate-pressure, and low-pressure hot water, respectively, and the low-pressure hot water is pumped through ejectors 25 and 26 so that the high-pressure hot water is sequentially sucked out by the ejector. A high-pressure production well 21, a medium-pressure production well 22, and a low-pressure production well 23 are connected in order from the farthest end. This ejector 2
The hot water integrated by 5 and 26 is transferred to the steam separator 2.
7, and the separated steam is sent to steam transport pipe 2.
8 to the turbine 29 for use. After driving the turbine 29, the steam is condensed in the injection condenser 32 and guided to the next stage of geothermal utilization equipment from the hot water tank 33, while non-condensable gas is released to the atmosphere.

The ejector 25 that integrates the high-pressure hot water from the production well 21 and the medium-pressure hot water from the production well 22 is
As shown in the figure, the nozzle 34 is configured to create a flow of high-pressure hot water, and at the interface of this flow, medium-pressure hot water is drawn in and ejected toward the low-pressure production well 23. Furthermore, the ejector 26 that integrates the hot water injected from the ejector 25 and the low-pressure hot water from the production well 23 is similarly configured.

In the conventional method, the steam from multiple production wells is combined with the steam from the production well with lower wellhead pressure, resulting in lower energy usage in the production wells with higher steam pressure, resulting in less wasted energy. was. this is,
One of the reasons for this is that if multiple production well steams were directly connected, the low pressure steam would be suppressed by the high pressure steam, so the steam had to be matched to the one with the lower pressure. As a result, the inlet pressure of the turbine becomes relatively low, resulting in poor turbine efficiency. On the other hand, as mentioned above, the ejector 2
5 and 26 are used to connect multiple production wells with different geothermal temperatures, the hot water from the low-pressure production well is sequentially sucked up by the hot water from the high-pressure production well, and when the hot water is integrated, a large amount of steam can be reduced. The higher pressure can be supplied to the turbine rather than the higher pressure. Therefore, the turbine can be operated efficiently.

The following Figure 4 is a diagram showing one embodiment of the indirect power generation equipment according to the present invention, in which 41 is a hot water supply section, 42 is a preheater/evaporator, 43 is a turbine, 44 is a generator,
45 is a compression pump, 46 is a condenser, and 47 is a medium pump. Using _CO2 as a medium, this
CO ₂ is supplied to the preheater/evaporator 42 by a medium pump 47 . This preheater/evaporator 42 also includes a hot water supply section 4 such as a geothermal production well or a direct power generation facility in the first stage.
1 to supply geothermal fluid at a low temperature of about 65 to 80 degrees Celsius. In this preheating/evaporator 42, 65~
Heat exchange is performed between geothermal fluid at a low temperature of about 80℃ and CO ₂ as a medium. The medium CO ₂ has a critical temperature of 35℃ and a temperature of 70Kg/
^cm2 , and it remains stable without thermal decomposition even if the temperature and pressure are increased to 65°C and 130Kg/ ^cm2 . Therefore, by utilizing the characteristics of the critical temperature of 35℃ and 70Kg/cm ² and the stable properties of CO ₂ , we can reduce the CO ₂ of the medium to 65℃ and 70Kg/cm 2.
The temperature and pressure are increased to 130Kg/cm ² and then supplied to the turbine 43. This drives the turbine 43 and the generator 4
4 generates electric power. The cold geothermal fluid discharged from the preheater/evaporator 42 is directed to a hot spring or other hot water utilization system. In addition, after turbine operation
The CO ₂ is cooled, compressed and liquefied by the compression pump 45 and returned to the condenser 46 . Then, this medium CO ₂ is supplied again from the condenser 46 to the preheater/evaporator 42 by the medium pump 47 and circulated.

FIG. 5 is a thermodynamic diagram for explaining the cycle of the power generation equipment shown in FIG. 4. In Figure 5, the vertical axis is temperature T, and the horizontal axis is enthalpy h (kcol/
Kg), 51 and 53 are the temperature change line of the geothermal fluid when CO ₂ is used as the medium and the saturated steam line of CO ₂ , and 52 and 54 are the temperature change line of the geothermal fluid when a fluorocarbon system is used as the medium. Shows the saturated vapor line of fluorocarbons. When a fluorocarbon system is used as the medium, the medium is pumped up from a to b, and then heated by a geothermal fluid whose temperature changes from a to ' to increase enthalpy and preheat and evaporate to b-c'-c''. Then, it expands from c'' to d in the turbine to do work (driving the turbine), and is cooled and condensed to d-e-a, returning to its initial state. On the other hand, if CO ₂ is used as the medium, the medium will move from a to b.
After being pressurized by a pump to , it is heated by a geothermal medium whose temperature changes from to to , increasing its enthalpy and preheating and evaporating from b to c. Therefore, if the exit temperature of the geothermal fluid is the same t ₃ , the inlet temperature t ₂ of the geothermal fluid when CO ₂ is used as the medium is higher than the inlet temperature t ₁ of the geothermal fluid when the medium is fluorocarbon. The maximum output power for the temperature range that can be used and the amount of heat released by the geothermal fluid (c″-d for _{t 1 - t 3 , c} for t ₂ - _{t 3 ,} -d)
Very good results can be obtained with this ratio.

For example, when the temperature of the geothermal fluid is not very high, or because the geothermal fluid is chemically highly acidic, it is difficult to obtain materials with sufficient corrosion resistance for the steam turbine casing and blades, causing reliability problems. Binary cycle power generation using a working medium will be adopted. In this binary cycle power generation, the thermal energy of geothermal fluid is transferred to a working medium and evaporated, and the steam of the working medium drives a turbine, and a generator connected to this generates electricity.However, in conventional power generation, geothermal fluid is The temperature of both is 150
℃ or above, and geothermal steam at around 80℃ has low power generation efficiency, so it has not been considered as a steam for power generation at present. However, as mentioned above, CO ₂ was used as the medium to raise the temperature and pressure at 65°C and 130°C.
If the turbine is driven at a temperature of around Kg/ ^cm2 , the temperature of the geothermal fluid used for this purpose can be sufficiently utilized even if it is around 65 to 80 degrees Celsius. Furthermore, if the geothermal fluid has a temperature higher than the critical temperature of CO ₂ (35°C), even if the temperature is 50°C, it is possible to raise the temperature and pressure of the medium beyond the critical state. It is also possible to drive a turbine using a geothermal body that has cooled considerably after generating electricity.

FIG. 6 is a diagram showing the configuration of one embodiment of the refrigeration equipment according to the present invention, in which 61 is an evaporation tank, 62 is a condensation tank, 63 and 64 are refrigerants, 65 is a pump, and 66
indicate the respective saucers.

In FIG. 6, refrigerants 63 and 64 are lithium bromide dihydrate (Li-Br.2H ₂ O) mixed with an alcoholic liquid such as ethanol or methanol. The mercury column approx.
It was housed under a vacuum of 75 mm, and the condensation tank 62 was housed under a vacuum of about 7 mm of mercury. Then, a pipe through which the evaporative hot water from the steam well flows back is passed through a column of refrigerant 63 housed in the evaporation tank 61.
3 is heated under a vacuum of about 75 mm of mercury. Refrigerant 63
Because it contains an alcohol-based liquid, its boiling point is low and it boils and evaporates even with steam or hot water at around 65°C. Further, above the surface of the refrigerant 63 of the evaporation tank 61, a pipe through which water from the outdoor cooler flows back is arranged, and a saucer 66 is arranged below the pipe, and the water vapor boiled and evaporated from the refrigerant 63 is collected here as wet steam. The water is then returned to the condensation tank 62 through the saucer 66, and cold water is generated by adiabatic expansion along the way.
This cold water is guided above the condensation tank 62, where it joins the cooling water pipe and the cooling refrigerant 64. As a result, the water flowing back through the cooling water pipes is cooled from 12°C to about 7°C. In this process, the temperature of the refrigerant 63 increases due to boiling and evaporation, and conversely, the concentration of the refrigerant 64 decreases due to the confluence of cold water.
It is also necessary to flow the refrigerant 64 back into the refrigerant 63 in the evaporation tank 61 using the pump 65 to maintain the refrigerant concentration at a predetermined value at all times.

As mentioned above, in the refrigerant equipment, lithium bromide dihydrate, whose boiling point has been further lowered by mixing an alcoholic liquid, is used as a refrigerant, and the water is evaporated and condensed in the evaporation tank 61. Cold water is generated by expansion and cools the water that flows back through the cooling water pipes. This makes it possible to effectively utilize low-temperature heat sources that were previously considered difficult to utilize. In addition, in Fig. 6, the cooling water whose temperature is controlled to 32°C by the outdoor cooler is transferred to the evaporation tank 61.
This is for supplementary cooling of the water vapor and the refrigerant 64 in the condensation tank 62, and improves the conditions of the evaporation tank 61 and the condensation tank 62. That is, in the evaporation tank 61, a part of the water vapor is cooled and condensed to become wet steam, thereby enhancing the adiabatic expansion effect, and in the condensation tank 62, the evaporation tank 6
The temperature of the refrigerant 64 is lowered so that the discharge temperature of the water recirculating through the cooling water pipe does not rise because the refrigerant 64 recirculates at a high temperature.

Geothermal energy is extracted in various forms such as steam, hot water, and mixed fluids of these, and its temperature ranges from high to low. However, in conventional geothermal energy use, the inlet temperature is at most 80°C or higher. It was said that the source was common, and anything less than that could not be used. Even with conventional refrigeration equipment that uses geothermal fluid, freshwater at 90°C is converted into hot water at 95°C, and this is used as a heat source to generate cold water at a temperature of about 5°C to 10°C. Therefore, in this refrigeration equipment, even if a low-temperature heat source exists, it cannot be used if the temperature is below the above-mentioned temperature, and a low-temperature heat source of 80°C or less has a coefficient of performance of only about 3 to 4 at best. , it was considered difficult to utilize it effectively. As mentioned above, when lithium bromide dihydrate (Li-Br.2H ₂ O) mixed with an alcohol-based liquid is used as a refrigerant, temperatures of 65°C to 68°C, which were previously considered difficult to utilize, can be used as a refrigerant.
The refrigerator can also be operated using low-temperature hot water as an energy source. Moreover, as a result, while the conventional coefficient of performance was about 3 to 4, it is possible to achieve a coefficient of performance of 7 to 9, which is double that. This makes it possible to utilize the thermal energy of low-temperature geothermal fluids more widely.

FIG. 7 is a diagram showing an embodiment of the configuration of a water turbine power generation equipment added to the power generation equipment of the geothermal utilization system according to the present invention, in which 71 is a condenser main body, 72 is an upper liquid reservoir, 73 is a central liquid reservoir, and 74 75 is a hot water tank, 76 is a water turbine, and 77 is a generator. This example is applied to a barometric capacitor. As mentioned earlier, the steam that is supplied to the steam turbine and does work is cooled in the condenser 71 and turned into water, and a part of it is sent to the cooling tower and cooled in the atmosphere, and then used as cooling water in the condenser 71. , the rest is hot water tank 75
It is stored in That is, in the barometric condenser, steam from the steam turbine comes into contact with a stream of cold water jetting downward from a number of water holes drilled at the bottom of the central liquid reservoir 73 and condenses.
are collected in. However, the steam that is not condensed here is further condensed by the flow of cold water falling from the upper liquid reservoir 72. Then, the non-condensable gas that does not condense here is also discharged from the upper exhaust port. On the other hand, the hot water collected in the lower reservoir 74 is stored in a hot water tank 75 and led to the next stage of geothermal utilization equipment, but in order to further utilize this hot water effectively, it is stored in the hot water tank 75 as shown in the figure. The heated water is guided to the water turbine 76 with a head difference, for example, by a pipe, and the water head pressure increases the negative pressure inside the condenser and drives the water turbine 76. The pressure in the condenser body is determined by the sum of the head H between the liquid level in the hot water tank 75 and the standard liquid level and the liquid depth h in the lower liquid reservoir 74. By guiding the air to the turbine 76, negative pressure can be generated inside the condenser. Therefore, the vacuum pump conventionally provided for preventing a drop in vacuum (0.1 to 0.3 ata) can be omitted or can be made to have a smaller capacity. This results in
The hot water (hot water) stored in the hot water tank 75 is not simply transported to the next stage of usage equipment, but after the steam turbine generates electricity, the potential energy is effectively utilized and the head is used to store it in the condenser. By applying head pressure to the heated water and generating electricity using a water turbine, the power generation efficiency of the entire system is increased.
Overall, the efficiency of geothermal energy use will be improved.

In the geothermal utilization system according to the present invention, as shown in FIG. 1, the utilization equipment is arranged according to the thermal energy possessed by the geothermal fluid, and the aim is to improve the overall utilization efficiency. For this reason, when transporting the geothermal fluid to the next stage of utilization equipment, it is also important to minimize loss and improve transport efficiency in the transport path along the way. An example of such a conveying means suitable for the present invention will be described next.

FIG. 8 is a diagram for explaining one embodiment of the vacuum conveyance system applied to the present invention, in which 81 is a hot water supply pipe, 82 is a hot water supply pump, 83 is a hot water storage tower, and 84 is an air conditioner/heater. Equipment, 85 is a conveyance pipe, 86 is a vacuum pump, 87 is geothermal utilization equipment, 8
8 is a hot water level detector, 89 is a level controller, and B is a drain valve. In FIG. 9, hot water is supplied from a hot water supply pipe 81 by a hot water supply pump 82 to a hot water storage tower 83 and stored there. The hot water storage tower 83 has a conveying pipe 8 for sending hot water to the next stage geothermal utilization equipment 87.
5 is connected, and a vacuum pump 86 is connected to the end of this conveying pipe 85. In addition, hot water storage tower 83
is provided with a hot water level detector 88 for detecting the level of hot water (water level), and a drain valve B for taking out hot water and precipitated impurities from the bottom. The level controller 89 controls the opening of the drain valve B according to the detection level of the hot water level detector 88. That is, the level controller 89 has an upper limit value and a lower limit value set as reference values of the control level, and opens the drain valve B to operate the hot water storage tower 83 on the condition that the detection level reaches the upper limit value. Discard hot water and precipitated impurities from the bottom, and drain valve B on the condition that the detection level has reached the lower limit.
close. Alternatively, it is of course possible to set only the drain start value as the reference value and open drain valve B for a temporary period on the condition that the detection level reaches the drain start value, or to adopt other control methods. It is. The refrigeration equipment 84 is
The energy released from the transport pipe 85 during transport is effectively utilized for heating and cooling.

Next, the operation of the illustrated system will be explained. When the hot water supply pump 82 is operated and hot water is supplied to the hot water storage tower 83, the vacuum pump 8
Since the pressure is reduced by the operation of step 6, the supplied hot water flashes into steam and is automatically and smoothly conveyed through the conveying pipe 85 in a form that does not contain impurities. Thermal energy that leaks to the outside when steam is transported through the transport pipe 85 is utilized by the refrigeration equipment 84, and the steam transported to the geothermal utilization equipment 87 is, for example, condensed and used as a hot spring. On the other hand, when the level of hot water (water level) rises in the hot water storage tower 83, the level controller 89 operates on the condition that the detection level of the hot water level detector 88 reaches a predetermined level (reference level). Drain valve B is opened. As a result, the excess hot water accumulated in the hot water storage tower 83 and the precipitated impurities deposited in the hot water are discarded. The impurities contained in the hot water left in the hot water storage tower 83 by flashing in this way are disposed of through the drain valve B after a predetermined period of time.

Conventionally, when the conveyance path is long and the piping becomes long or the piping becomes complicated, this has been dealt with by increasing the transportation power. Therefore, it is necessary to install a fairly large-scale transport pump depending on the thickness and length of the transport pipe and the complexity of the piping, which poses the problem of increasing equipment costs and maintenance costs for transportation and maintenance. Ta. Furthermore, since the hot water is sent through normal piping, impurities contained in the hot water are also sent as they are. The impurities in this hot water precipitate as so-called scale, and adhere to the inner walls of piping and block the conveyance path, or adhere to hot water utilization equipment and cause various problems. As a result, even more equipment and costs are required to remove it. On this point, in this system, as mentioned above, a vacuum pump is operated at the end of the transfer pipe to draw a vacuum inside the transfer pipe and the hot water storage tower, thereby flushing the hot water and causing the flushing. Since it is automatically transported in the form of steam, 90-95% of impurities can be removed by leaving them in the hot water, and since the only power required is to operate a vacuum pump, the temperature is around 50-60℃. Even low-temperature hot water can be transported using 30% less power than transporting the hot water itself due to steam expansion of the hot water.

FIG. 9 is a diagram for explaining one embodiment of a hot water conveyance path applied to the present invention, in which 91 is a concrete frame, 92 is a conveyance pipe, 93 is a flexible pipe,
94 is a heat insulating air layer, 95 is a heat insulating material, 96 is a support stand, 97 is a channel, and 98 is a drain.

In FIG. 9a, a conveying pipe 92 is a concrete pipe for passing hot water. The flexible pipe 93 covers the conveying pipe 92 and is made of plastic conduit (manufactured by Furukawa Electric, for example). A heat insulating air layer 94 is formed between the transport pipe 92 and the flexible pipe 93, and is filled with air for heat insulation. Further, a heat insulating material 95 is filled between the flexible pipe 93 and the concrete frame 91, and the flexible pipe 93 is positioned and fixed within the concrete frame 91 using a support stand 96 as appropriate. FIG. 9b shows a cross section of the portion where the support stand 96 is provided (cross section A-B in FIG. 9a).

In the hot water conveyance path configured as shown in FIGS. 9a and 9b above, since the heat insulating air layer 94 exists, the plastic flexible tube 93 can maintain heat resistance, and hot water leaks from the conveyance tube 92. However, due to the expansion of the heat insulating air layer 94 due to the temperature rise, pressure is generated to prevent water leakage. In addition, even if hot water leaks from the conveying pipe 92, since the flexible pipe 93 is made of water-retaining plastic, the hot water will only stay in the heat insulating air layer 94 and will not reach the heat insulating material 95. Since no effect occurs, the temperature can be prevented from decreasing. Further, unlike in the conventional case, hot water does not leak and penetrate into the heat insulating material 95 and deteriorate it, so the quality of the heat insulating material can be maintained and there is no need to use particularly expensive heat insulating materials.

Conventional methods for transporting geothermal fluids, mainly hot water, include covering the channel for transporting hot water with concrete and transporting the hot water through the channel;
Some systems transport hot water through a concrete channel by covering the channel with glass wool insulation (or double urethane). However, conventional methods of transporting hot water often involve a structure such as burying iron pipes in underground trenches, resulting in a temperature drop of 0.1 to 1°C/Km, making them quite expensive, which makes multi-purpose use difficult. Development has been delayed considerably. That is, if hot water permeates the heat insulating material due to water leakage from the concrete pipe and expands due to this heat, the heat insulating material is destroyed, making it impossible to maintain the above temperature drop. If heat retention is insufficient, the temperature drop will be large, especially when the atmospheric temperature is low, and the loss of effective energy will also be large. On the other hand, in the hot water conveyance path described above, water leakage from a conveyance pipe such as a concrete pipe to the heat insulating material can be prevented by a plastic flexible pipe, so that the water leakage does not have an adverse effect on the heat insulating material. Therefore, even if an inexpensive preservation material is used, it can be used satisfactorily. Further, since a heat insulating air layer is provided between the conveying pipe and the flexible pipe, it is possible to improve heat retention and prevent or suppress water leakage.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, all of the thermal energy contained in geothermal fluid is utilized from high-temperature geothermal fluid to low-temperature hot water that can be used for hot springs, so overall heat utilization efficiency is extremely high. can be obtained. Furthermore, since the facilities used are diverse, the normally required energy for electricity, heating and cooling, and even hot springs can be covered by the thermal energy of geothermal fluid extracted from production wells, making it possible to save energy.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining one embodiment of the geothermal utilization system according to the present invention, FIG. 2 is a diagram showing the configuration of one embodiment of the hydrothermal energy integration section and direct power generation equipment according to the present invention, The figure is a diagram for explaining the ejector used in the hot water energy integration section in Figure 2, and Figure 4 is a diagram for explaining an ejector used in the hot water energy integration section of Figure 2.
5 is a thermodynamic diagram for explaining the cycle of the power generation equipment shown in FIG. 4; FIG. 6 is a diagram showing the configuration of an embodiment of the refrigeration equipment according to the present invention; FIG. The figure shows the configuration of an embodiment of the water turbine power generation equipment added to the power generation equipment of the geothermal utilization system according to the present invention, and FIG. 9 are diagrams for explaining one embodiment of a hot water conveyance path applied to the present invention. 11 and 16... Hydrothermal Energy Integration Department, 12...
...Direct power generation equipment, 13...Indirect power generation equipment, 14...
... Refrigeration equipment, 15... Hot water usage equipment.

Claims (1)

[Scope of Claims] 1. A geothermal utilization system that utilizes the thermal energy of geothermal fluid produced from geothermal production wells, which includes geothermal direct power generation equipment that directly generates electricity using high-temperature geothermal fluid, and carbon dioxide as a heat medium. Equipped with indirect power generation equipment that exchanges heat with medium-temperature geothermal fluid to generate electricity, refrigeration equipment that uses medium-temperature geothermal fluid as a heat source to cool water by absorption refrigeration, and hot spring and other hot water utilization equipment, which generates electricity from geothermal production wells. The geothermal fluid is supplied to one of the above facilities according to the temperature to utilize the thermal energy, and the geothermal fluid after utilization is then sequentially supplied to the facilities on the low temperature side to utilize the thermal energy up to the hot water utilization facility. A geothermal utilization system characterized by being configured as follows. 2. The geothermal utilization system according to claim 1, wherein the geothermal direct power generation equipment is driven by an atmospheric pressure turbine that uses 100°C saturated steam as input energy. 3. Indirect power generation equipment is characterized by using carbon dioxide as a medium and driving the turbine by raising the temperature and pressure of carbon dioxide to 65℃ and 130Kg/cm ³ through indirect contact with geothermal fluid at a medium temperature of 50 to 80℃. A geothermal utilization system according to claim 1. 4. Any one of claims 1 to 3, characterized in that it is equipped with a water turbine power generation facility that increases the negative pressure of the condenser by giving water head pressure to the discharged water generated in the condenser, and drives a water turbine to generate electricity. Geothermal utilization system described in. 5. Claim 1, characterized in that the refrigeration equipment uses lithium bromide dihydrate mixed with an alcohol-based liquid as a refrigerant, so that a high coefficient of performance can be obtained even with a medium-temperature heat source. Geothermal utilization system described. 6 Geothermal fluid is produced by sequentially connecting multiple production wells from the production well on the high-pressure side to the production well on the low-pressure side, and sequentially sucking up hot water from the production well on the low-pressure side by ejecting hot water from the production well on the high-pressure side. The geothermal utilization system according to claim 1, characterized in that water is extracted in an integrated manner. 7 A vacuum pump is connected to the end of the conveyance path, and the vacuum pump is used to create a vacuum inside the conveyance pipe and the hot water storage tower in which hot water is stored, thereby flushing the hot water in the hot water storage tower and turning it into steam. 2. The geothermal utilization system according to claim 1, wherein the geothermal energy is automatically conveyed. 8. The geothermal utilization system according to claim 1, wherein the conveyed steam in the conveying pipe is used as a heat source for refrigeration equipment. 9. The hot water is conveyed through a hot water conveyance path that covers the conveyor tube with a flexible tube made of watertight plastic and fills air between the conveyor tube and the flexible tube to form an insulating air layer. A geothermal utilization system according to claim 1 characterized by: