JP2022037979A - Binary geothermal power generation system - Google Patents

Abstract

To provide a binary geothermal power generation system capable of eliminating a reduction water pump or suppressing the power consumption of the reduction water pump, and preventing precipitation of silica or the like, to effectively utilize geothermal energy.SOLUTION: A binary geothermal power generation system 1 separates geothermal fluid collected from a production well into steam and hot water by a steam separator 3, exchanges heat between the separated steam and hot water and a low-boiling point medium by an evaporator 5, and drives a binary turbine 9 using the steam of the low-boiling point medium thus generated, to generate power; and returns the separated hot water as reduction water to a reduction well, where a steam injector 21 is provided in a reduction water line 19 that returns the reduction water to the reduction well. The binary geothermal power generation system is configured to introduce part of the steam separated by the steam separator 3 and the reduction water into the steam injector 21, and raise the temperature and pressure of the reduction water to return it to the reduction well.SELECTED DRAWING: Figure 1

Description

The present invention relates to a binary geothermal power generation system.

A binary geothermal power generation system, for example, as exemplified in the background technology of Patent Document 1, exchanges heat with a geothermal fluid collected from a production well and a low boiling medium, and uses the steam generated thereby to generate a binary turbine. It is to drive and generate electricity.

FIG. 10 is a diagram showing the configuration of a general binary geothermal power generation system 43. In FIG. 10, 3 is a steam separator that separates geothermal fluid collected from a production well into steam, and 5 is a low-boiling medium (butane) that exchanges heat between steam separated by the steam separator 3 and a low-boiling medium. , A preheater that evaporates (hydrogenate such as pentane), 7 is a preheater that exchanges heat between the hot water separated by the steam separator 3 and the low boiling medium to preheat the low boiling medium, and 9 is the evaporator 5. A binary turbine that introduces and drives the generated steam, 11 is a generator driven by the binary turbine 9, 13 is a cooling tower (air cooling) that cools and liquefies the steam discharged from the binary turbine 9, and 15 is a circulation line. A circulation pump provided in 16 for circulating a liquefied low boiling medium, 17 is a reducing water pump for returning hot water heat exchanged by a preheater 7 to a reducing well.

In the binary geothermal power generation system 43 configured as described above, the geothermal fluid collected from the production well is separated into hot water and steam by the steam separator 3, and the steam is sent to the evaporator 5. The hot water is sent to the preheater 7.
On the other hand, the low boiling point medium circulates in the circulation line 16 by the circulation pump 15, is preheated by the preheater 7, becomes steam by the evaporator 5, is introduced into the binary turbine 9, and the binary turbine 9 is driven to be binary. The generator 11 is driven by the drive of the turbine 9 to generate electricity.
The steam supplied to the binary turbine 9 is liquefied by the cooling tower 13 and supplied to the preheater 7 by the circulation pump 15.
The steam is condensed by heat exchange in the evaporator 5 to become hot water, which is supplied to the preheater 7 together with the hot water supplied from the air-water separator 3, preheats the low boiling point medium, and then is reduced by the reduced water pump 17. Returned to the well.

FIG. 10 shows an example of the flow rate, temperature, etc. of hot water or the like in the middle of the system when the geothermal fluid having the dimensionless flow rate (1) is collected from the production well.
The geothermal fluid is separated by the air-water separator 3 into steam having a flow rate (0.162), a temperature of 130 ° C. and a pressure of 0.3 MPa, and hot water having a flow rate (0.838), a temperature of 130 ° C. and a pressure of 0.3 MPa. The water and hot water supplied to the preheater 7 become reduced water having a flow rate (1) and a temperature of 100 ° C., are boosted to 0.4 MPa by the reduced water pump 17, and returned to the reducing well.

Japanese Unexamined Patent Publication No. 2018-53738

In the binary geothermal power generation system 43 as described above, the electric power of the reducing water pump 17 driven by the electric motor is required, and the amount of electric power supplied to the outside is reduced by the amount of the electric power consumption.
In addition, the geothermal fluid generally contains silica, calcium, etc., and these tend to precipitate when the temperature is low. Therefore, the hot water separated by the air-water separator 3 is returned to the reduction well near the transport pipe or reduction well. It adheres to the water and becomes a flow path resistance, which causes an increase in transportation power and a decrease in the amount of swallowing of the reduction well. As a result, steam and hot water cannot be produced as planned, resulting in a decrease in power generation output and a decrease in the economic efficiency of geothermal power plants.

For example, when the silica concentration of the geothermal fluid is less than 390 mg / L, if the reduced water temperature is 100 ° C, the operation can be performed without precipitating silica. Therefore, in order to avoid the above problems, the reduced water can be operated. It is necessary to keep the temperature at about 100 ° C or higher, but in this case, there is a problem that the geothermal energy of hot water cannot be fully utilized and the energy utilization efficiency is poor.
Further, even if the temperature of the reduced water is 100 ° C. or higher, depending on the properties of the produced geothermal fluid, silica may be contained that exceeds the silica solubility of the reduced water. Causes problems.

The present invention has been made to solve such a problem, and is a binary type capable of effectively utilizing geothermal energy by eliminating the need for a reduced water pump, suppressing the power consumption of the reduced water pump, and preventing the precipitation of silica and the like. The purpose is to provide a geothermal power generation system.

(1) In the binary geothermal power generation system according to the present invention, the geothermal fluid collected from the production well is separated into steam and hot water by a steam separator, and the separated steam and / or hot water is evaporated. The steam of the low boiling medium generated by exchanging heat with the low boiling medium is used to drive a binary turbine to generate power, and the separated hot water is returned to the reduction well as reduced water. ,
A steam injector is provided in the reduced water line for returning the reduced water to the reducing well, and a part of the steam separated by the steam separator and the reduced water are introduced into the steam injector to adjust the temperature of the reduced water. It is characterized by increasing the pressure and returning it to the reduction well.

(2) Further, in the above (1), the first flow rate adjusting valve for adjusting the flow rate of the geothermal fluid collected from the production well and the second flow rate adjusting for adjusting the flow rate of the steam supplied to the steam injector. With a valve,
A first flow rate detecting device that detects the flow rate of steam supplied to the evaporator side or another steam utilization side, a second flow rate detecting device that detects the flow rate of water vapor supplied to the steam injector, and a supply to the steam injector. A third flow rate detector that detects the flow rate of reduced water,
The first temperature detection device that detects the temperature of the steam supplied to the steam injector, the second temperature detection device that detects the temperature of the reduced water supplied to the steam injector, and the temperature of the reduced water discharged from the steam injector. A third temperature detector that detects
A second pressure detecting device that detects the pressure of the reduced water supplied to the steam injector, a third pressure detecting device that detects the pressure of the reduced water discharged from the steam injector, and the pressure of the throat portion of the steam injector. The 4th pressure detection device to detect and
A power detection device that detects the power generated by the turbine, and
Of the steam separated by the steam separator, the distribution ratio of the steam supplied to the evaporator or other steam utilization side and the amount of steam flowing into the steam injector, the production increase ratio of the production well and the increase rate of the binary power generation output Relationship, silica concentration analysis value contained in geothermal fluid, steam to hot water ratio of geothermal fluid, database containing design specifications of binary power generators and steam injectors,
The flow rate of the geothermal fluid to input the detection signal of each detection device to obtain the required power output based on the information stored in the database, and to prevent silica from being deposited by the reduced water, or silica. It is provided with a control device that calculates the flow rate of steam supplied to the steam injector, which is required to suppress the precipitation of water vapor, and controls the first flow rate adjusting valve and the second flow rate adjusting valve based on the calculated value. It is characterized by that.

(3) Further, in the above (1), the first flow rate adjusting valve for adjusting the flow rate of the geothermal fluid collected from the production well and the second flow rate adjusting for adjusting the flow rate of the steam supplied to the steam injector. With a valve,
A first flow rate detecting device that detects the flow rate of steam supplied to the evaporator side or another steam utilization side, a second flow rate detecting device that detects the flow rate of water vapor supplied to the steam injector, and a supply to the steam injector. A third flow rate detector that detects the flow rate of reduced water,
A second temperature detecting device that detects the temperature of the reduced water supplied to the steam injector, and a third temperature detecting device that detects the temperature of the reduced water discharged from the steam injector.
A first pressure detecting device that detects the pressure of the steam supplied to the steam injector, a second pressure detecting device that detects the pressure of the reduced water supplied to the steam injector, and the pressure of the reduced water discharged from the steam injector. A third pressure detecting device for detecting the pressure of the throat portion of the steam injector, and a fourth pressure detecting device for detecting the pressure in the throat portion of the steam injector.
A power detection device that detects the power generated by the turbine, and
Of the steam separated by the steam separator, the distribution ratio of the steam supplied to the evaporator or other steam utilization side and the amount of steam flowing into the steam injector, the production increase ratio of the production well and the increase rate of the binary power generation output Relationship, silica concentration analysis value contained in geothermal fluid, steam to hot water ratio of geothermal fluid, database containing design specifications of binary power generators and steam injectors,
The flow rate of the geothermal fluid to input the detection signal of each detection device to obtain the required power output based on the information stored in the database, and to prevent silica from being deposited by the reduced water, or silica. It is provided with a control device that calculates the flow rate of water vapor supplied to the steam injector, which is required to suppress the precipitation of water vapor, and controls the first flow rate adjusting valve and the second flow rate adjusting valve based on the calculated value. It is characterized by that.

(4) In the binary geothermal power generation system according to the present invention, water vapor, which is a geothermal fluid collected from a production well, is heat-exchanged with a low-boiling medium by an evaporator, and the steam of the low-boiling medium generated thereby is used. This is a binary geothermal power generation system that drives a binary turbine to generate power and returns the condensed water condensed with steam by the evaporator to the reduction well as reduced water.
A steam injector is provided in the reducing water line for returning the reduced water to the reduction well, and a part of the steam which is the geothermal fluid and the reduced water are introduced into the steam injector to raise the temperature and pressure of the reduced water. It is characterized by returning it to the reduction well.

In the present invention, a steam injector is provided in the reducing water line that returns the reduced water to the reduction well, and the steam separated by the steam separator and the reduced water are introduced into the steam injector to introduce the temperature and pressure of the reduced water. By raising the amount of water and returning it to the reduction well, the reduced water pump is unnecessary or the power consumption of the reduced water pump can be suppressed, and the precipitation of silica or the like can be prevented to effectively utilize the geothermal energy.

It is explanatory drawing explaining the structure of the binary type geothermal power generation system which concerns on this embodiment. It is explanatory drawing of the steam injector used in the binary type geothermal power generation system shown in FIG. It is explanatory drawing of another aspect of the binary type geothermal power generation system which concerns on this embodiment (the 1). It is a graph which shows the solubility curve of silica in water. It is explanatory drawing of another aspect of the binary type geothermal power generation system which concerns on this embodiment (the 2). It is explanatory drawing of another aspect of the binary type geothermal power generation system which concerns on this embodiment (the 3). It is explanatory drawing of another aspect of the binary type geothermal power generation system which concerns on this embodiment (the 4). It is explanatory drawing of Example 1 of the binary type geothermal power generation system which concerns on this embodiment. It is explanatory drawing of Example 2 of the binary type geothermal power generation system which concerns on this embodiment. It is explanatory drawing explaining the structure of the conventional binary type geothermal power generation system.

The binary geothermal power generation system according to the present embodiment will be described with reference to FIG. In FIG. 1, the same reference numerals are given to the parts common to FIG. 10 in which the conventional example is described, and the description thereof will be omitted.

In the binary geothermal power generation system 1 according to the present embodiment, the geothermal fluid collected from the production well is separated into steam and hot water by the steam separator 3, and the separated steam and hot water are used as a low boiling point medium. It exchanges heat with (hydrocarbons such as butane and pentane) and uses the steam generated by this to drive the binary turbine 9 to generate power, and at the same time, the separated hot water is returned to the reduction well as reduced water. ..
Then, a steam injector 21 is provided in the reduced water line 19 for returning the reduced water to the reducing well, and a part of the steam separated by the steam separator 3 and the reduced water are introduced into the steam injector 21 to bring the temperature of the reduced water. I am trying to raise the pressure and return it to the reduction well.
The present embodiment is characterized in that the steam injector 21 is provided in the reduced water line 19 that returns the reduced water to the reducing well. Therefore, the configuration and operation of the steam injector 21 will be described below.

<Steam injector>
The steam injector 21 is a device that generally mixes steam with a liquid stream and transfers the heat and momentum to obtain a jet liquid having a temperature and pressure higher than the introduced liquid pressure.
As shown in FIG. 2, the steam injector 21 includes a tubular reduced water supply unit 23 to which reduced water is supplied, and a steam supply unit 25 provided so as to cover the reduced water supply unit 23 and to which steam is supplied. A mixing section 27 in which reduced water and steam are mixed, a throat section 29 whose diameter is reduced on the downstream side of the mixing section 27, and a diffuser section 31 whose diameter is expanded on the downstream side of the throat section 29 are provided.

In the steam injector 21 configured as described above, when the reduced water is supplied to the reduced water supply unit 23 and the steam is supplied to the steam supply unit 25, the steam and the reduced water come into contact with each other in the mixing unit 27 to condense the steam. The pressure inside the steam injector 21 (mixing section 27) decreases due to the condensation of steam, so that the action of sucking the reduced water and steam occurs.

When 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). In addition, the contact between the steam and the reduced water causes the steam to condense, and the temperature of the reduced water rises. Then, the flow velocity of the reduced water (mixed water) is reduced in the diffuser portion 31 whose diameter is expanded after passing through the throat portion 29, the pressure is recovered by this, and the reduced water (mixed water) is increased in pressure and discharged.

As described above, by providing the steam injector 21 in the reduced water line 19, the water pressure of the reduced water can be increased by the steam injector 21, so that the reduced water pump 17 becomes unnecessary or the reduced water pump 17 is used. The power can be reduced.
Further, the steam injector 21 causes the reduced water to come into contact with the steam, so that the temperature of the reduced water rises and the precipitation of silica and the like can be prevented.
Specific examples of the pressure increase and the temperature increase of the reduced water will be described in Examples described later.

The steam injector 21 described above is provided so that the steam supply unit 25 covers the reduced water supply unit 23, but the present invention is not limited to this, and the supplied reduced water and steam are in contact with each other. It suffices if the structure is such that it flows out in the same direction. For example, contrary to the above-mentioned one, the reduced water supply unit 23 may be provided so as to cover the cylindrical steam supply unit 25.

Further, in order to facilitate the outflow of the internal fluid when the steam injector 21 is started, a drain pipe 33 is provided on the throat portion 29 or the upstream side thereof, and the fluid is allowed to flow in the drain pipe 33 only in the direction of outflow from the steam injector 21. An on-off valve, for example, a check valve 35 may be provided. By doing so, the effect of facilitating the activation of the steam injector 21 can be obtained.

Since the geothermal power generation system 1 in the above embodiment uses a part of the primary steam separated by the steam separator 3 in the steam injector 21, the amount of steam used in the binary geothermal power generation system is reduced. , The power generation output is reduced by that amount.
In this respect, in order to make the power generation output the same as when the steam injector 21 is not used, the production increase ratio of the production well may be controlled to be supplemented by the thermal energy from the geothermal fluid to be increased.
As described above, a control method in which a part of the primary steam is used in the steam injector 21 while the power generation output remains the same or is arbitrarily required as the power generation output will be described with reference to FIG.

As an example of the device configuration in this case, as shown in FIG. 3, a first flow rate adjusting valve 37 for adjusting the flow rate of the geothermal fluid is provided in the line for collecting the geothermal fluid from the production well, and the air / water separator 3 is used. A second flow rate adjusting valve 39 for adjusting the amount of water vapor is provided in a line for supplying water vapor to the steam injector 21, and a control device 41 for controlling the first flow rate adjusting valve 37 and the second flow rate adjusting valve 39 is provided.
In FIG. 3, F1 to F3, T1 to T3, P1 to P4, and W indicate a flow rate detection device, a temperature detection device, a pressure detection device, and a power detection device, respectively, and the detection signal of each device is controlled. It is input to the device 41.

Specific examples of each detection device are as follows.
F1: First flow detection device that detects the flow rate of steam supplied to the evaporator 5 side F2: Second flow rate detection device that detects the flow rate of steam supplied to the steam injector 21 F3: Reduced water supplied to the steam injector 21 Third flow detection device that detects the flow rate T1: First temperature detection device that detects the temperature of the steam supplied to the steam injector 21 T2: Second temperature detection device that detects the temperature of the reduced water supplied to the steam injector 21 T3: Third temperature detection device that detects the temperature of the reduced water discharged from the steam injector 21 P1: First pressure detection device that detects the pressure of the steam supplied to the steam injector 21 P2: Pressure of the reduced water supplied to the steam injector 21 2nd pressure detection device to detect P3: 3rd pressure detection device to detect the pressure of the reduced water discharged from the steam injector 21 P4: 4th pressure detection device to detect the pressure of the throat part of the steam injector 21 W: Binary A power detection device that detects the power generated by the turbine 9 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 therefore, by using the saturated steam table, the other value can be uniquely calculated from the detected value of either temperature or pressure.

In addition, the distribution ratio of the amount of steam supplied to the evaporator 5 side and the amount of steam flowing into the steam injector 21 among the steam separated by the steam separator 3, the production increase ratio of the production well and the increase ratio of the binary power generation output. Necessary for controlling the relationship with, geothermal fluid properties (silica concentration analysis value contained in geothermal fluid, ratio of steam to hot water of geothermal fluid, temperature, pressure, etc.), design specifications of binary power generator and steam injector 21. Information on the equipment and the like is stored as a database in the control device 41.
The pressure detecting device provided in the steam injector 21 detects the pressure in the throat portion (throat portion 29) of the steam injector 21.

By providing the device configuration as described above, the detection signal of each device is input to the control device 41, and the control device 41 should supply the water vapor amount to the steam injector 21 based on the input detection signal and the information in the database. Or, the required geothermal fluid flow rate is calculated, and the first flow rate adjusting valve 37 and / or the second flow rate adjusting valve 39 is controlled based on the calculation result.

Specific examples 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 rate adjusting valve 37 and / or the second flow rate adjusting valve 39 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. The reduced water is obtained by separating water vapor from the geothermal fluid, and silica is concentrated as compared with the geothermal fluid. Therefore, the flow rate ratio between the geothermal fluid and the reduced water is calculated based on the flow rates of water vapor and reduced water measured by the flow rate detecting device, and the silica concentration of the concentrated reduced water is calculated. Next, the saturation temperature of the silica concentration of the reduced water is calculated from the solubility curve of silica in water shown in FIG. 4, and the temperature of the reduced water required to prevent silica and the like from precipitating is raised from the saturation temperature and the temperature of the reduced water. Calculate the quantity. Based on this, the ratio of the amount of steam supplied to the steam injector 21 and the flow rate of reduced water is calculated. Further, the maximum ejection pressure at the injector outlet is calculated based on this calculated value and the specifications of the steam injector 21.

From the above-mentioned maximum discharge pressure at the injector outlet, the ratio of steam supplied to the steam injector 21 and the flow rate of reduced water, and the ratio of steam and hot water of the geothermal fluid produced from the production well, reduction is performed by the boosting action of the steam injector 21. Calculate the range of possible increase in production of possible production wells. The range in which production can be increased here means an increase in production based on the production amount (1) of the production well when the steam injector shown in FIG. 10 is not used.

The power generation output possible range is calculated based on the calculated production well production increaseable range, and the power generation output is determined within this power generation output possible range. The power generation output to be determined is, for example, a power generation output required according to the power demand situation, a power generation output when the steam injector 21 is not used, or the like.
The first flow rate regulating valve 37 is controlled so that the determined power generation output is obtained, and the production of geothermal fluid is increased. At the same time, the second flow control valve 39 controls the amount of steam flowing into the steam injector 21 so that the flow ratio of the steam of the steam injector 21 to the reduced water becomes the calculated value described above.

In the above, the silica concentration of the reduced water was calculated and the temperature of the reduced water was raised to the saturation temperature at the silica concentration to control the silica so as not to precipitate. However, a certain amount of precipitation is allowed. In such a case, the amount of temperature rise may be adjusted to suppress the precipitation of silica by a predetermined ratio. The calculation method of the amount of temperature rise in this case is shown below.

The rate at which silica precipitation is suppressed (hereinafter referred to as “suppression rate”) is set in advance (for example, when the amount of silica precipitation is desired to be reduced by 30%, the suppression rate is set to 0.3).
When the saturation concentration of the reduced water to be targeted in order to achieve the above suppression rate is set to "target saturation concentration", the suppression rate can be defined by the following formula (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 saturation concentration at the reduced water temperature is calculated from the solubility curve of silica in water (see FIG. 4), and the target saturation 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 realize the calculated target saturation concentration is calculated. Based on this, the ratio of the amount of primary steam supplied to the steam injector 21 and the flow rate of reduced water is calculated. By controlling the amount of water vapor flowing into the steam injector 21 with the second flow rate adjusting valve 39 based on the calculated value, it is possible to suppress the precipitation of silica by a predetermined ratio.

Further, in the above description, the steam separated by the air-water separator 3 is supplied to the evaporator 5, but the binary geothermal power generation system of the present invention is not limited to this, and is not limited to this, as shown in FIG. As shown, the evaporator 5 may be supplied with hot water separated by the steam separator 3. In this case, the steam separated by the steam separator 3 is supplied to the steam injector 21 and another steam utilization side, for example, a flash power generation device.

In the case shown in FIG. 5, the apparatus configuration in the case of control in which a part of the primary steam is used by the steam injector 21 while the power generation output remains the same or is set to an arbitrary power generation output is shown in FIG. This is true, and the specific operation and the like are the same as those described in FIG.
In the example of FIG. 6, F1 is provided on another line on the steam utilization side.

Further, in the examples shown in FIGS. 1, 3, 5, and 6, the geothermal fluid collected from the production well was separated into steam and hot water by the steam separator 3, but the geothermal heat. When the fluid is almost steam without accompanying hot water, as shown in FIG. 7, even if steam is directly introduced into the evaporator 5 and the steam injector 21 without providing the steam separator 3. good. In this case, a steam injector 21 is provided in the reduced water line 19 that returns the condensed water in which the steam is condensed by the evaporator 5 to the reducing well as reduced water, and a part of the steam which is a geothermal fluid and the reduced water are introduced into the steam injector 21. Then, the temperature and pressure of the reduced water are raised so that it can be returned to the reducing well.
Since the condensed water in which steam is condensed has a low silica concentration, it is not necessary to positively suppress silica precipitation. However, by providing the steam injector 21 in the reduced water line 19, it is effective to increase the water pressure of the reduced water. The reduced water pump 17 becomes unnecessary, or the power of the reduced water pump 17 can be reduced.

FIG. 8 shows an example of applying a steam injector when the production of steam / hot water is increased by 10% in the case shown in FIG.
By introducing steam having a dimensionless flow rate (0.021) and hot water having a dimensionless flow rate (1.079) into the steam injector 21, the temperature of the reduced water can be raised by 10 ° C. Since the silica solubility at 100 ° C is about 390 mg / L and the silica solubility at 110 ° C is about 420 mg / L, when the silica concentration of the produced geothermal fluid is 420 mg / L, per 1 L of reduced water before applying the steam injector. 30 mg of silica was precipitated, but it is no longer precipitated by applying the steam injector 21.

When the silica concentration of the produced geothermal fluid is 420 mg / L or more, silica is deposited even if the steam injector 21 is applied, but the amount of precipitation is suppressed compared to before the application, so the maintenance cost of the reduced water pipe is Additional excavation costs for return wells will be reduced by reducing or extending the period of use. Further, since the outlet pressure of the steam injector 21 can be made higher than the pressure of the air-water separator 3, the pump power for transporting the reduced water to the reducing well is reduced.

As another application example, FIG. 9 shows an operation example when the hot water temperature at the outlet of the preheater is 80 ° C.
In the case of this example, the flow rate of steam flowing into the evaporator 5 is reduced by the amount of steam introduced into the steam injector 21, but since the preheater 7 uses hot water up to 80 ° C., the power generation output is the same. Become.
Also in this example, at the outlet of the steam injector 21, the temperature of the reduced water can be increased to 100 ° C. and the discharge pressure can be increased to 0.6 MPa, so that the pump power for transporting the reduced water to the reducing well is reduced.

As shown in the above embodiment, by applying the steam injector 21 to the binary power generation system, the scale generation in the reduction well is suppressed by heating the reduced water, and the pump power is reduced by boosting the reduced water (supplied to the outside). It can be expected to have effects such as (increasing the amount of power that can be generated).

1 Binary geothermal power generation system 3 Air-water separator 5 Evaporator 7 Preheater 9 Binary turbine 11 Generator 13 Cooling tower 15 Circulation pump 16 Circulation line 17 Reduced water pump 19 Reduced water line 21 Steam injector 23 Reduced water supply unit 25 Steam Supply part 27 Mixing part 29 Throat part 31 Diffuser part 33 Drain pipe 35 Check valve 37 1st flow control valve 39 2nd flow control valve 41 Control device 43 Binary type geothermal power generation system (conventional example)
F1 1st flow rate detection device F2 2nd flow rate detection device F3 3rd flow rate detection device T1 1st temperature detection device T2 2nd temperature detection device T3 3rd temperature detection device P1 1st pressure detection device P2 2nd pressure detection device P3 2nd 3 Pressure detector P4 4th pressure detector W Power detector

Claims (4)

The geothermal fluid collected from the production well was separated into steam and hot water by a steam separator, and the separated steam and / or hot water was heat-exchanged with a low boiling point medium by an evaporator, which was produced. It is a binary geothermal power generation system that drives a binary turbine to generate power using the steam of the low boiling point medium and returns the separated hot water to the reduction well as reduced water.
A steam injector is provided in the reduced water line for returning the reduced water to the reducing well, and a part of the steam separated by the steam separator and the reduced water are introduced into the steam injector to adjust the temperature of the reduced water. A binary geothermal power generation system characterized by increasing the pressure and returning it to the reduction well. A first flow rate adjusting valve that adjusts the flow rate of the geothermal fluid collected from the production well, and a second flow rate adjusting valve that adjusts the flow rate of the steam supplied to the steam injector.
A first flow rate detecting device that detects the flow rate of steam supplied to the evaporator side or another steam utilization side, a second flow rate detecting device that detects the flow rate of water vapor supplied to the steam injector, and a supply to the steam injector. A third flow rate detector that detects the flow rate of reduced water,
The first temperature detection device that detects the temperature of the steam supplied to the steam injector, the second temperature detection device that detects the temperature of the reduced water supplied to the steam injector, and the temperature of the reduced water discharged from the steam injector. A third temperature detector that detects
A second pressure detecting device that detects the pressure of the reduced water supplied to the steam injector, a third pressure detecting device that detects the pressure of the reduced water discharged from the steam injector, and the pressure of the throat portion of the steam injector. The 4th pressure detection device to detect and
A power detection device that detects the power generated by the turbine, and
Of the steam separated by the steam separator, the distribution ratio of the steam supplied to the evaporator or other steam utilization side and the amount of steam flowing into the steam injector, the production increase ratio of the production well and the increase rate of the binary power generation output Relationship, silica concentration analysis value contained in geothermal fluid, steam to hot water ratio of geothermal fluid, database containing design specifications of binary power generators and steam injectors,
The flow rate of the geothermal fluid to input the detection signal of each detection device to obtain the required power output based on the information stored in the database, and to prevent silica from being deposited by the reduced water, or silica. It is provided with a control device that calculates the flow rate of water vapor supplied to the steam injector required to suppress the precipitation of water vapor and controls the first flow rate adjusting valve and the second flow rate adjusting valve based on the calculated value. The binary geothermal power generation system according to claim 1, wherein the system is characterized in that. A first flow rate adjusting valve that adjusts the flow rate of the geothermal fluid collected from the production well, and a second flow rate adjusting valve that adjusts the flow rate of the steam supplied to the steam injector.
A first flow rate detecting device that detects the flow rate of steam supplied to the evaporator side or another steam utilization side, a second flow rate detecting device that detects the flow rate of water vapor supplied to the steam injector, and a supply to the steam injector. A third flow rate detector that detects the flow rate of reduced water,
A second temperature detecting device that detects the temperature of the reduced water supplied to the steam injector, and a third temperature detecting device that detects the temperature of the reduced water discharged from the steam injector.
A first pressure detecting device that detects the pressure of the steam supplied to the steam injector, a second pressure detecting device that detects the pressure of the reduced water supplied to the steam injector, and the pressure of the reduced water discharged from the steam injector. A third pressure detecting device for detecting the pressure of the throat portion of the steam injector, and a fourth pressure detecting device for detecting the pressure in the throat portion of the steam injector.
A power detection device that detects the power generated by the turbine, and
Of the steam separated by the steam separator, the distribution ratio of the steam supplied to the evaporator or other steam utilization side and the amount of steam flowing into the steam injector, the production increase ratio of the production well and the increase rate of the binary power generation output Relationship, silica concentration analysis value contained in geothermal fluid, steam to hot water ratio of geothermal fluid, database containing design specifications of binary power generators and steam injectors,
The flow rate of the geothermal fluid to input the detection signal of each detection device to obtain the required power output based on the information stored in the database, and to prevent silica from being deposited by the reduced water, or silica. It is provided with a control device that calculates the flow rate of water vapor supplied to the steam injector required to suppress the precipitation of water vapor and controls the first flow rate adjusting valve and the second flow rate adjusting valve based on the calculated value. The binary geothermal power generation system according to claim 1, wherein the system is characterized in that. Water vapor, which is a geothermal fluid collected from a production well, is heat-exchanged with a low-boiling medium by an evaporator, and the steam of the low-boiling medium generated by this is used to drive a binary turbine to generate power, and the evaporator. It is a binary geothermal power generation system that returns the condensed water condensed by steam to the reduction well as reduced water.
A steam injector is provided in the reducing water line for returning the reduced water to the reduction well, and a part of the steam which is the geothermal fluid and the reduced water are introduced into the steam injector to raise the temperature and pressure of the reduced water. A binary geothermal power generation system characterized by returning to the reduction well.

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