JP7331807B2 - Geothermal power generation system - Google Patents

Description

The present invention relates to geothermal power generation systems.

Geothermal power generation systems include a flash geothermal power generation system and a binary geothermal power generation system, as exemplified in the prior art of Patent Document 1.
Of these, the flash geothermal power generation system separates the geothermal fluid collected from the production well into steam and hot water with a steam separator, and uses the separated steam and the flash steam generated from the hot water with a flasher. It drives a turbine to generate electricity.

A binary geothermal power generation system, like the flash geothermal power generation system described above, is exemplified in the background art of Patent Document 1, in which heat is exchanged between a geothermal fluid collected from a production well and a low-boiling-point medium. The steam generated by the steam is used to drive a binary turbine to generate electricity.

FIG. 7 is a diagram showing the configuration of a general flash-type geothermal power generation system 49. As shown in FIG.
In FIG. 7, 3 is a steam-water separator that separates the geothermal fluid extracted from the production well into primary steam and hot water, and 5 flashes the hot water separated by the steam-water separator 3 to produce a secondary A flasher for generating steam, 7 a turbine driven by introducing the primary steam separated by the steam separator 3 and the secondary steam generated by the flasher 5, 9 a generator driven by the turbine 7, 11 is a condenser that cools and liquefies the steam discharged from the turbine 7; 13 is a condensate pump that is provided in the condensate line 15 and sends the condensate liquefied in the condenser 11 to the cooling tower; is a cooling tower for cooling condensate; 19 is a flash tank for releasing the hot water discharged from the flasher 5 to the atmosphere; It is a reinjection water pump that returns hot water to the reinjection well.

In the geothermal power generation system 49 configured as described above, the geothermal fluid collected from the production well is separated into hot water and primary steam by the steam separator 3, and the primary steam is sent to the turbine 7. , the hot water is sent to the flasher 5 . The hot water sent to the flasher 5 is flashed by the flasher 5 and secondary steam generated thereby is introduced into the turbine 7 .
The turbine 7 is driven by the primary steam and the secondary steam introduced into the turbine 7, and the driving of the turbine 7 drives the generator 9 to generate electric power.
The steam (primary steam and secondary steam) supplied to the turbine 7 is liquefied by the condenser 11 and supplied to the cooling tower 17 by the condensate pump 13 . A part of the condensate cooled by the cooling tower 17 is used as cooling water for the condenser 11 and is returned to the return well.
On the other hand, hot water coming out of flasher 5 is supplied to flash tank 19 . The steam generated from the flash tank 19 is reduced or thermally utilized, and the hot water enters the retention tank 21 open to the atmosphere. Geothermal fluid generally contains silica, calcium and the like, and these are precipitated and removed by staying in the retention tank 21 for about one hour, and then returned to the reinjection well by the reinjection water pump 23 .

FIG. 7 shows an example of the flow rate, temperature, etc. of hot water, etc. in the middle of the system when the geothermal fluid of the dimensionless flow rate (1) is sampled from the production well.
The geothermal fluid is separated by the steam separator 3 into primary steam with a flow rate of 0.26 and a temperature of 160°C and hot water with a flow rate of 0.74 and a temperature of 160°C. The flasher 5 generates secondary steam with a flow rate (0.051) and a temperature of 120°C, and then the hot water is supplied to the flash tank 19. used for heat. After that, the hot water passes through the retention tank 21 to become reduced water having a flow rate of 0.665 and a temperature of 95° C., which is pressurized to 0.4 MPa by the reduced water pump 23 and returned to the injection well.

JP-A-2018-53738

In the geothermal power generation system 49 as described above, power is required for the reduced water pump 23 driven by the electric motor, and the amount of power supplied to the outside is reduced by the power consumption.
Generally, the hot water in the retention tank 21 is supersaturated with components such as silica and calcium as described above, and does not decrease to the saturation concentration even after retention. As a result, the reinjection water adheres to the transport pipe and the vicinity of the reinjection well, resulting in flow path resistance, resulting in an increase in transport power and a decrease in the intake amount of the reinjection well. As a result, steam and hot water cannot be produced as planned, resulting in lower power output and lower economic efficiency of the geothermal power plant.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to provide a geothermal power generation system that eliminates the need for a reduced water pump or suppresses the power consumption of the reduced water pump and that can prevent deposition of silica and the like. and

(1) A geothermal power generation system according to the present invention separates a geothermal fluid collected from a production well into steam and hot water by a steam-water separator, and uses the separated steam and hot water thermal energy to produce a turbine. is driven to generate power, and the hot water is returned to the reinjection well as reinjection water, wherein a steam injector is provided in the reinjection water line for returning the reinjection water to the reinjection well, and the steam injector is provided with the steam separator Part of the steam separated in step 1 and the reduced water are introduced, the temperature and pressure of the reduced water are increased, and the reduced water is returned to the reduction well.

(2) The geothermal power generation system according to the present invention separates the geothermal fluid collected from the production well into primary steam and hot water by the steam-water separator, and separates the separated primary steam and hot water. The secondary steam generated by being introduced into the flasher is used to drive a turbine to generate electricity, and the hot water discharged from the flasher is returned to the injection well as return water, wherein the return water is returned to the injection well. A steam injector is provided in the reducing water line to be returned, and part of the primary steam separated by the steam separator and the reducing water are introduced into the steam injector to increase the temperature and pressure of the reducing water. It is characterized in that it is returned to the reinjection well.

(3) In addition, in the above (2), a first flow control valve for adjusting the flow rate of the geothermal fluid extracted from the production well, and a second flow control valve for adjusting the flow rate of the primary steam supplied to the steam injector. a flow control valve, a first flow rate detection device for detecting a flow rate of primary steam supplied to the turbine, a second flow rate detection device for detecting a flow rate of primary steam supplied to the steam injector, and a supply to the turbine a third flow rate detection device for detecting the flow rate of the secondary steam to be supplied to the steam injector; a fourth flow rate detection device for detecting the flow rate of the reduced water supplied to the steam injector; and a temperature of the primary steam supplied to the steam injector. A first temperature detection device, a second temperature detection device for detecting the temperature of the reduced water supplied to the steam injector, a third temperature detection device for detecting the temperature of the reduced water discharged from the steam injector, and the steam. A second pressure detection device for detecting the pressure of the reduced water supplied to the injector, a third pressure detection device for detecting the pressure of the reduced water discharged from the steam injector, and a pressure at the throat portion of the steam injector. a fourth pressure detection device, a power detection device that detects the power generated by the turbine, steam supplied to the turbine side of the primary steam separated by the steam separator, and the amount of steam that flows into the steam injector. distribution ratio of production wells, relationship between production increase ratio of production wells and flash power generation output increase rate, silica concentration analysis value contained in geothermal fluid, ratio of steam and hot water in geothermal fluid, design specifications of flash power generation equipment and steam injectors. A storage database and a detection signal of each detection device are input, and the flow rate of the geothermal fluid for obtaining the required power generation output based on the information stored in the database, and the reduced water that does not precipitate silica the flow rate of the primary steam to be supplied to the steam injector required to suppress the deposition of silica, and based on the calculated value, the first flow control valve and the second flow control valve is characterized by comprising a control device for controlling the

(4) In addition, in the above (2), a first flow control valve for adjusting the flow rate of the geothermal fluid extracted from the production well, and a second flow control valve for adjusting the flow rate of the primary steam supplied to the steam injector. a flow control valve, a first flow rate detection device for detecting a flow rate of primary steam supplied to the turbine, a second flow rate detection device for detecting a flow rate of primary steam supplied to the steam injector, and a supply to the turbine a third flow rate detection device for detecting the flow rate of the secondary steam to be supplied to the steam injector; a fourth flow rate detection device for detecting the flow rate of the reduced water supplied to the steam injector; and a fourth flow rate detection device for detecting the temperature of the reduced water supplied to the steam injector. 2 temperature detection device, a third temperature detection device for detecting the temperature of the reducing water discharged from the steam injector, a first pressure detection device for detecting the pressure of the primary steam supplied to the steam injector, and the steam. A second pressure detection device for detecting the pressure of the reduced water supplied to the injector, a third pressure detection device for detecting the pressure of the reduced water discharged from the steam injector, and a pressure at the throat portion of the steam injector. a fourth pressure detection device, a power detection device that detects the power generated by the turbine, steam supplied to the turbine side of the primary steam separated by the steam separator, and the amount of steam that flows into the steam injector. distribution ratio of production wells, relationship between production increase ratio of production wells and flash power generation output increase rate, silica concentration analysis value contained in geothermal fluid, ratio of steam and hot water in geothermal fluid, design specifications of flash power generation equipment and steam injectors. A storage database and a detection signal of each detection device are input, and the flow rate of the geothermal fluid for obtaining the required power generation output based on the information stored in the database, and the reduced water that does not precipitate silica the flow rate of the primary steam to be supplied to the steam injector required to suppress the deposition of silica, and based on the calculated value, the first flow control valve and the second flow control valve is characterized by comprising a control device for controlling the

(5) The geothermal power generation system according to the present invention uses the thermal energy of steam, which is a geothermal fluid collected from a production well, to drive a turbine to generate power, and the condensed water of the steam is sent to the reinjection well as reinjection water. A steam injector is provided in a reducing water line for returning the reducing water to the reducing well, and a part of the steam that is the geothermal fluid and the reducing water are introduced into the steam injector to remove the reducing water. It is characterized by raising the temperature and pressure and returning it to the injection well.

(6) A geothermal power generation system according to the present invention uses steam, which is a geothermal fluid collected from a production well, to drive a turbine to generate power, and cools the steam discharged from the turbine. is returned to the reinjection well as reinjection water, and a steam injector is provided in the reinjection water line for returning the reinjection water to the ininjection well, and part of the steam, which is the geothermal fluid, and the reinjection water are introduced into the steam injector. Then, the temperature and pressure of the reducing water are raised and returned to the reducing well.

In the present invention, a steam injector is provided in a reduced water line returning reduced water to a reduced well, and primary steam separated by a steam separator and reduced water are introduced into the steam injector to increase the temperature of the reduced water. By increasing the pressure and returning it to the reinjection well, it is possible to eliminate the need for a reinjection water pump or suppress the power consumption of the reinjection water pump, and prevent precipitation of silica and the like.

1 is an explanatory diagram illustrating the configuration of a geothermal power generation system according to an embodiment; FIG. FIG. 2 is an explanatory diagram of a steam injector used in the geothermal power generation system shown in FIG. 1; FIG. 4 is an explanatory diagram of another aspect of the geothermal power generation system according to the present embodiment (No. 1); 1 is a graph showing a solubility curve of silica in water; FIG. 2 is an explanatory diagram of another aspect of the geothermal power generation system according to the present embodiment (No. 2); 1 is an explanatory diagram of an example of a geothermal power generation system according to this embodiment; FIG. 1 is an explanatory diagram for explaining the configuration of a conventional geothermal power generation system; FIG.

A geothermal power generation system according to the present embodiment will be described with reference to FIG. 1, taking a flash system as an example. In FIG. 1, parts common to those in FIG. 7 explaining the conventional example are denoted by the same reference numerals, and explanations thereof are omitted.

In the flash-type geothermal power generation system 1 according to the present embodiment, the geothermal fluid collected from the production well is separated into primary steam and hot water by the steam-water separator 3, and the separated primary steam and , hot water is introduced into the flasher 5 and secondary steam generated is used to drive the turbine 7 to generate electricity, and the hot water discharged from the flasher 5 is returned to the reinjection well as reinjection water.
A steam injector 27 and a water pump 28 for feeding the reduced water to the injector 27 are provided in the reduced water line 25 for returning the reduced water to the return well. In addition, the reduced water is introduced to raise the temperature and pressure of the reduced water and return it to the injection well.
This embodiment is characterized in that a steam injector 27 is provided in the return water line 25 for returning the return water to the return well, so the configuration and operation of the steam injector 27 will be described below.

<Steam injector>
The steam injector 27 is generally a device that mixes steam with the liquid flow and transfers its heat and momentum to obtain a jet liquid having a higher temperature and higher pressure than the introduced liquid pressure.
As shown in FIG. 2, the steam injector 27 includes a cylindrical reduced water supply portion 29 to which reduced water is supplied, and a steam supply portion 31 provided to cover the reduced water supply portion 29 and to which steam is supplied. , a mixing portion 33 where the reducing water and steam are mixed, a throat portion 35 downstream of the mixing portion 33 with a reduced diameter, and a diffuser portion 37 with an enlarged diameter downstream of the throat portion 35 .

In the steam injector 27 configured as described above, when the reduced water is supplied to the reduced water supply section 29 and the steam (primary steam) is supplied to the steam supply section 31, the steam and the reduced water come into contact with each other in the mixing section 33 to produce steam. condenses. As the pressure inside the steam injector 27 (the mixing section 33) decreases due to the condensation of the steam, an action of sucking the reduced water and the steam occurs.

When the water vapor is sucked, it becomes a high-speed flow, and this kinetic energy is transferred to the reduced water to accelerate the reduced water (mixed water). Also, the contact between the water vapor and the reduced water raises the temperature of the reduced water. After the reducing water (mixed water) passes through the throat portion 35, the flow velocity decreases in the diffuser portion 37 having an enlarged diameter, whereby the pressure is recovered and the reducing water (mixed water) is discharged at a raised pressure.

As described above, since the steam injector 27 is provided in the reduced water line 25, the water pressure of the reduced water can be increased by the steam injector 27. Power can be reduced.
In addition, the steam injector 27 brings the reduced water into contact with steam (primary steam), thereby heating the reduced water to increase the saturation concentration and diluting the reduced water to decrease the silica concentration. It is also possible to prevent precipitation of such as.
A specific example of the pressure increase and temperature increase of the reducing water will be described later in Examples.

The steam injector 27 described above is provided so that the steam supply section 31 covers the reducing water supply section 29, but the present invention is not limited to this. It is sufficient that they have a structure in which they flow out in the same direction. For example, contrary to what has been described above, the reduced water supply section 29 may be provided so as to cover the cylindrical steam supply section 31 .

In addition, in order to make it easier for the fluid inside to flow out when the steam injector 27 is activated, a drain pipe 39 is provided at the throat portion 35 or its upstream side, and the fluid is made to flow only in the direction of flowing out of the steam injector 27 into the drain pipe 39. An on-off valve such as a check valve 41 may be provided. By doing so, the effect of facilitating activation of the steam injector 27 is obtained.

In this embodiment, the steam injector 27 is provided in the reduced water line 25 that sends the reduced water from the storage tank 21, but the steam injector 27 is provided in the condensate line 15 that sends condensate from the cooling tower 17. do not have. This is because the primary steam generated in the steam separator 3 and the secondary steam generated in the flasher 5 have a low silica concentration, and the condensed water obtained by liquefying the steam in the condenser suppresses silica precipitation. because it is not necessary.
However, since the power of the pump can be reduced by providing the steam injector, the power consumption of the condensate pump 13 may be suppressed by providing the steam injector in the condensate line 15 .

In the geothermal power generation system 1 according to the above embodiment, a part of the primary steam separated by the steam separator 3 is used by the steam injector 27, so the amount of primary steam used in the flash power generation system is reduced. , the power generation output decreases accordingly.
In this regard, in order to make the power output the same as when the steam injector 27 is not used, the production increase ratio of the production well may be controlled so as to compensate for the thermal energy from the increased production of geothermal fluid.
A control method for using a portion of the primary steam in the steam injector 27 while maintaining the power output at the same level or at any required power output in this manner will be described with reference to FIG.

As an example of the device configuration in this case, as shown in FIG. A line for supplying steam to the steam injector 27 is provided with a second flow control valve 45 for adjusting the amount of steam (primary steam), and a control device 47 for controlling the first flow control valve 43 and the second flow control valve 45 is provided. set up.
In FIG. 3, F1 to F4, T1 to T3, P1 to P4, and W indicate the flow rate detection device, temperature detection device, pressure detection device, power detection device, and liquid level detection device, respectively. A detection signal is input to the control device 47 .

The details of each detection device are as follows.
F1: First flow rate detection device for detecting the flow rate of primary steam supplied to turbine 7 F2: Second flow rate detection device for detecting the flow rate of primary steam supplied to steam injector 27 F3: Secondary flow rate detection device for supplying to turbine 7 Third flow rate detection device for detecting the flow rate of steam F4: Fourth flow rate detection device for detecting the flow rate of the reducing water supplied to the steam injector 27 T1: First temperature for detecting the temperature of the primary steam supplied to the steam injector 27 Detection device T2: Second temperature detection device for detecting the temperature of the reduced water supplied to the steam injector 27 T3: Third temperature detection device for detecting the temperature of the reduced water discharged from the steam injector 27 P1: Supply to the steam injector 27 P2: A second pressure detection device that detects the pressure of the reduced water supplied to the steam injector 27 P3: Detects the pressure of the reduced water discharged from the steam injector 27 Third pressure detection device P4: Fourth pressure detection device that detects the pressure at the throat portion of the steam injector 27 W: Power detection device that detects the power generated by the turbine 7 L: Liquid level that detects the liquid level in the retention tank 21 Detecting Device Although both T1 and P1 are shown in FIG. 3, only one of them may be installed. This is because the steam separated from the steam separator 3 is saturated steam, and the saturated steam table can be used to uniquely calculate one of the detected values of temperature and pressure from the detected value of the other.

In addition, among the primary steam separated by the steam separator 3, the distribution ratio between the amount of primary steam supplied to the turbine 7 side and the amount of primary steam flowing into the steam injector 27, the production increase ratio of the production well and the flash Relationship with the rate of increase in power generation output, properties of geothermal fluid (analysis value of silica concentration contained in geothermal fluid, ratio of steam to hot water in geothermal fluid, temperature, pressure, etc.), design specifications of flash power generator and steam injector 27, etc. Information such as equipment required for the control of is stored in the control device 47 as a database.
Note that the pressure detection device provided in the steam injector 27 detects the pressure of the throat portion (throat portion 35 ) of the steam injector 27 .

By providing the device configuration as described above, the detection signal of each device is input to the control device 47, and the control device 47 based on the input detection signal and the information of the database, the primary fuel to be supplied to the steam injector 27. The amount of steam and the required geothermal fluid flow rate are calculated, and the first flow control valve 43 and/or the second flow control valve 45 are controlled based on the calculation results.

A specific example of such control will be described below. The purpose of this control is to raise the temperature of the reduced water to a temperature at which silica or the like does not precipitate, and to control the first flow control valve 43 and/or the second flow control valve 45 so as to obtain the required power generation output. is.
First, the silica concentration of the reduced water is calculated from the silica concentration analysis value of the geothermal fluid. Reduced water is the separation of water vapor from the geothermal fluid and is enriched in silica relative to the geothermal fluid. Therefore, the flow ratio of the geothermal fluid and the reduced water is calculated based on the flow rates of the primary steam, the secondary steam, and the reduced water measured by the flow rate detector, and the concentration of silica in the concentrated reduced water is calculated. Next, the saturation temperature of the silica concentration in the reducing water is calculated from the solubility curve of silica in water, an example of which is shown in FIG. Calculate quantity. Based on this, the ratio between the amount of primary steam supplied to the steam injector 27 and the flow rate of the reduced water is calculated. Also, based on this calculated value and the specification of the steam injector 27, the injector outlet maximum discharge pressure is calculated.

From the maximum discharge pressure of the injector outlet, the ratio of the primary steam supplied to the steam injector 27 and the flow rate of the reductive water, and the ratio of the steam and hot water of the geothermal fluid produced from the production well, the pressurizing action of the steam injector 27 Calculate the possible production increase range of production wells that can be reduced by The production increase possible range here means the increase in production relative to the production (1) of the production well when the steam injector shown in FIG. 7 is not used as a reference.

A possible power generation output range is calculated based on the calculated possible increase in production range of the production well, and the power generation output is determined within this possible power generation output range. The power output to be determined is, for example, the power output required according to the power demand situation, the power output when the steam injector 27 is not used, or the like.
The first flow regulating valve 43 is controlled so as to achieve the determined power generation output to increase the production of geothermal fluid. At the same time, the second flow control valve 45 controls the amount of primary steam flowing into the steam injector 27 so that the flow ratio of the primary steam to the reducing water in the steam injector 27 becomes the above-described calculated value.

In the above description, the silica concentration of the reduced water is calculated, and the temperature of the reduced water is raised to the saturation temperature at that silica concentration to control the silica so that it does not precipitate, but a certain amount of precipitation is allowed. In such a case, the amount of temperature rise may be adjusted to suppress silica precipitation by a predetermined ratio. A method of calculating the amount of temperature increase in this case is shown below.

A ratio of suppressing silica deposition (hereinafter referred to as "suppression rate") is set in advance (for example, if the amount of silica deposition is to be reduced by 30%, the suppression rate is set to 0.3).
When the saturation concentration of the reducing water to be targeted for achieving the above suppression rate is defined as the "target saturation concentration", the suppression rate can be defined by the following equation (1).
Suppression rate = (target saturation concentration - saturation concentration at reduced water temperature)
/ (reduced water silica concentration - saturated concentration at reduced water temperature) (1)

After obtaining the silica concentration of the reduced water as described above, the saturated concentration at the reduced water temperature is calculated from the solubility curve of silica in water (see FIG. 4), and the target saturated concentration is calculated based on the above formula (1). . Further, from the solubility curve of silica in water, the amount of temperature rise of the reduced water required to achieve the calculated target saturation concentration is calculated. Based on this, the ratio between the amount of primary steam supplied to the steam injector 27 and the flow rate of the reduced water is calculated. By controlling the amount of primary steam flowing into the steam injector 27 with the second flow control valve 45 based on the calculated value, silica deposition can be suppressed by a predetermined ratio.

Theoretically, it is preferable to control the reducing water at the saturation temperature because it does not increase the production uselessly. In the above control, it is assumed that the liquid level detector provided in the retention tank 21 detects the amount of water in the retention tank 21 and the flow rate condition of the reducing water includes level control of the retention tank 21 .

In the example shown in FIGS. 1 and 3, the geothermal fluid collected from the production well is separated into steam and hot water by the steam separator 3. 5, the steam may be introduced directly into the turbine 7 and the steam injector 27 without providing the steam separator 3, as shown in FIG. In this case, the steam discharged from the turbine 7 is liquefied in the condenser 11, the condensed water is introduced into the reduced water line 25 as reduced water, and the steam injector 27 provided in the reduced water line 25 is injected with the geothermal fluid. Part of a certain steam and reducing water are introduced to raise the temperature and pressure of the reducing water so that it is returned to the reducing well.
As described above, since the condensed water obtained by liquefying steam has a low silica concentration, it is not necessary to actively suppress silica deposition. Since it is effective, the reduced water pump 23 becomes unnecessary, or the power of the reduced water pump 23 can be reduced.

Although the flash geothermal power generation system 1 has been described in the present embodiment, the present invention is not limited to this, and can also be applied to, for example, a binary geothermal power generation system.
As described above, the binary geothermal power generation system separates the geothermal fluid collected from the production well with a steam-water separator, and heat-exchanges the separated steam and hot water with a low-boiling-point medium, thereby The generated steam is used to drive a binary turbine. A steam injector is installed in the reduced water line that returns the reduced water after heat exchange to the reduction well. A similar effect can be obtained by raising the

In the case shown in FIG. 7, an application example of the steam injector in the case of raising the temperature of the reduced water to a temperature at which silica or the like does not precipitate will be described below.
For example, when the concentration of silica in the reducing water at the outlet of the retention tank 21 is 480 ppm, the saturation temperature is 115°C (see Fig. 4). An example will be described with reference to FIG.

In this example, the production of geothermal fluid is increased by 10% in order to raise the temperature of the reducing water to 115° C. with the steam injector 27 . Since the primary steam for the increased production of the production well is introduced into the steam injector 27, the flow rate of the primary steam introduced into the turbine 7 is the same as in the example shown in FIG. 7, and the power generation output is the same.

By introducing the primary steam of the non-dimensional flow rate (0.028), which is the increased production of the production well, to the steam injector 27, the temperature of the reduced water can be raised to 115 ° C. When the silica concentration is 480 ppm or less, the steam injector Application of 27 prevents precipitation of silica.

If the silica concentration of the produced geothermal fluid is 480 ppm or more, silica will precipitate even if the steam injector 27 is applied. Additional excavation costs for reinjection wells can be reduced by reducing maintenance costs for piping and extending the period of use.

On the other hand, increasing the production of geothermal fluid also increases the flow rate of hot water. This can be addressed by the boosting effect of 27, which will be explained below.

Since the pressure required to transport water to the reinjection well is proportional to the square of the flow rate, as in this example, if the reinjected water flow rate increases by 1.14 times (0.665 → 0.757), the required pressure will increase by about 1.3 times. In the case of the mass balance shown in FIG. 6, the boosting effect of the injector 27 can be increased by about 1.3 times from the original reduction pressure, which can cover the required pressure increase (1.3 times) due to increased production.
In this way, the steam injector 27 can provide a pressurizing effect that exceeds the pressure increase required by the increase in production, so the pump power for transporting the reinjection water to the reinjection well can be reduced.

As shown in the above embodiment, by applying the steam injector 27 to the flash power generation system, it is possible to suppress scale formation in the return well by heating the return water, and reduce pump power by increasing the pressure of the return water (supply to the outside). (Increase in the amount of power that can be generated) can be expected.

1 geothermal power generation system 3 steam separator 5 flasher 7 turbine 9 power generator 11 condenser 13 condensate pump 15 condensate line 17 cooling tower 19 flash tank 21 retention tank 23 reduced water pump 25 reduced water line 27 steam injector 28 water supply Pump 29 Reduced water supply unit 31 Steam supply unit 33 Mixing unit 35 Throat unit 37 Diffuser unit 39 Drain pipe 41 Check valve 43 First flow control valve 45 Second flow control valve 47 Control device 49 Geothermal power generation system (conventional example)
F1 First flow detector F2 Second flow detector F3 Third flow detector F4 Fourth flow detector T1 First temperature detector T2 Second temperature detector T3 Third temperature detector P1 First pressure detector P2 2 pressure detection device P3 3rd pressure detection device P4 4th pressure detection device W power detection device L liquid level detection device

Claims (2)

The geothermal fluid collected from the production well is separated into primary steam and hot water by a steam-water separator, and the separated primary steam and the secondary steam generated by introducing the hot water into the flasher are used. a geothermal power generation system that drives a turbine to generate power and returns hot water discharged from the flasher to a reinjection well as reinjection water,
A portion of the primary steam separated by the steam separator is provided in a reduced water line for returning the reduced water to the reduction well, and the reduced water is introduced to increase the temperature and pressure of the reduced water. a steam injector returning to the reduction well;
a first flow control valve that adjusts the flow rate of geothermal fluid extracted from a production well; a second flow control valve that adjusts the flow rate of primary steam supplied to the steam injector;
A first flow rate detection device for detecting a flow rate of primary steam supplied to the turbine, a second flow rate detection device for detecting a flow rate of primary steam supplied to the steam injector, and a secondary steam flow rate to be supplied to the turbine. a third flow rate detection device for detecting the flow rate; a fourth flow rate detection device for detecting the flow rate of the reduced water supplied to the steam injector;
a first temperature detection device for detecting the temperature of the primary steam supplied to the steam injector; a second temperature detection device for detecting the temperature of the reduced water supplied to the steam injector; and the reduced water discharged from the steam injector. a third temperature detection device that detects the temperature of
a second pressure detection device for detecting the pressure of the reduced water supplied to the steam injector; a third pressure detection device for detecting the pressure of the reduced water discharged from the steam injector; a fourth pressure sensing device for sensing;
a power detection device that detects power generated by the turbine;
Among the primary steam separated by the steam separator, the distribution ratio between the steam supplied to the turbine side and the amount of steam flowing into the steam injector, the relationship between the production increase ratio of production wells and the increase ratio of flash power output, geothermal a database storing analytical values of silica concentration contained in the fluid, the ratio of steam to hot water in the geothermal fluid, design specifications of the flash power generator and the steam injector;
The flow rate of the geothermal fluid for inputting the detection signal of each detection device and obtaining the required power generation output based on the information stored in the database, and for preventing silica from being precipitated by the reduced water, or silica A control device that calculates the flow rate of the primary steam to be supplied to the steam injector required to suppress the deposition of A geothermal power generation system comprising: The geothermal fluid collected from the production well is separated into primary steam and hot water by a steam-water separator, and the separated primary steam and the secondary steam generated by introducing the hot water into the flasher are used. a geothermal power generation system that drives a turbine to generate power and returns hot water discharged from the flasher to a reinjection well as reinjection water,
A portion of the primary steam separated by the steam separator is provided in a reduced water line for returning the reduced water to the reduction well, and the reduced water is introduced to increase the temperature and pressure of the reduced water. a steam injector returning to the reduction well;
a first flow control valve that adjusts the flow rate of geothermal fluid extracted from a production well; a second flow control valve that adjusts the flow rate of primary steam supplied to the steam injector;
A first flow rate detection device for detecting a flow rate of primary steam supplied to the turbine, a second flow rate detection device for detecting a flow rate of primary steam supplied to the steam injector, and a secondary steam flow rate to be supplied to the turbine. a third flow rate detection device for detecting the flow rate; a fourth flow rate detection device for detecting the flow rate of the reduced water supplied to the steam injector;
a second temperature detection device for detecting the temperature of the reduced water supplied to the steam injector; a third temperature detection device for detecting the temperature of the reduced water discharged from the steam injector;
a first pressure detection device for detecting pressure of primary steam supplied to the steam injector; a second pressure detection device for detecting pressure of the reduced water supplied to the steam injector; and reduced water discharged from the steam injector. a third pressure sensing device for sensing the pressure of the steam injector; a fourth pressure sensing device for sensing the pressure at the throat portion of the steam injector;
a power detection device that detects power generated by the turbine;
Among the primary steam separated by the steam separator, the distribution ratio between the steam supplied to the turbine side and the amount of steam flowing into the steam injector, the relationship between the production increase ratio of production wells and the increase ratio of flash power output, geothermal a database storing analytical values of silica concentration contained in the fluid, the ratio of steam to hot water in the geothermal fluid, design specifications of the flash power generator and the steam injector;
The flow rate of the geothermal fluid for inputting the detection signal of each detection device and obtaining the required power generation output based on the information stored in the database, and for preventing silica from being precipitated by the reduced water, or silica A control device that calculates the flow rate of the primary steam to be supplied to the steam injector required to suppress the deposition of A geothermal power generation system comprising:

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