Non-condensable gas reduction system

Abstract

The present disclosure provides a non-condensable gas reduction system that returns non-condensable gas contained in highly maintainable geothermal fluid to a reinjection well. **Solution**: A non-condensable gas reduction system used in a geothermal power plant, comprising: a gas-liquid separator that separates geothermal fluid gushing out from a production well into a first gas and a first liquid; a turbine rotated by the first gas; and a condenser that cools the first gas rotated by the turbine and condenses vapor contained in the first gas into a second liquid, the non-condensable gas reduction system further comprising: a pump that pressurizes a third liquid sent to a reinjection well; a plurality of ejectors driven by the third liquid, attracting non-condensable gas contained in the first gas and remaining uncondensed in the condenser, and discharging a fourth liquid in which the third liquid and the non-condensable gas are mixed; and a plurality of lines provided in parallel, including any one of the plurality of ejectors, wherein the first liquid and the fourth liquid are mixed and sent to the reinjection well.

Description

Technical Field

[0001] The present disclosure relates to a non-condensable gas reduction system.

Background Art

[0002] Patent Document 1 discloses a method for disposing of non-condensable gas generated in a geothermal power generation facility, in which the non-condensable gas generated in a condenser provided downstream of a steam turbine is injected into a reduction well for hot water reduction, and is reduced underground together with the reduction hot water.

[0003] Patent Document 2 discloses a geothermal power generation plant including a reduction water flow path for transporting reduction water to a reduction well, a gas extraction device for extracting gas from a condenser, and a gas flow path for supplying the gas extracted from the condenser to the reduction water flow path and mixing it into the reduction water.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In geothermal power generation, when non-condensable gas such as carbon dioxide or hydrogen sulfide is contained, gas accumulates in the upper part of the condenser or evaporator directly below the turbine, causing a decrease in the degree of vacuum and a decrease in heat exchange efficiency. In order to prevent a decrease in the degree of vacuum and a decrease in heat exchange efficiency, non-condensable gas is removed by an extractor or the like. The extracted non-condensable gas is sent from the condenser or evaporator to a cooling tower, for example, mixed with air, and discharged to the atmosphere.

[0006] The present disclosure provides a non-condensable gas reduction system that returns non-condensable gas contained in a geothermal fluid with high maintainability to a reduction well.

Means for Solving the Problem

[0007] The present disclosure relates to a non-condensable gas reduction system used in a geothermal power plant, comprising a gas-liquid separator that separates geothermal fluid gushing out from a production well into a first gas and a first liquid, a turbine rotated by the first gas, and a condenser that cools the first gas rotated by the turbine and condenses the vapor contained in the first gas into a second liquid. The non-condensable gas reduction system further comprises a pump that pressurizes a third liquid sent to a reduction well, and an ejector driven by the third liquid that attracts non-condensable gas contained in the first gas and remaining uncondensed in the condenser, and discharges a fourth liquid in which the third liquid and the non-condensable gas are mixed. The non-condensable gas reduction system provides a system in which the first liquid and the fourth liquid are mixed and sent to the reduction well.

Advantages of the Invention

[0008] The present disclosure provides a non-condensable gas reduction system that returns non-condensable gas contained in geothermal fluid with high maintainability to a reduction well.

Brief Description of the Drawings

[0009]

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DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to these examples, and is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0011] Regarding the descriptions in the specifications and drawings according to each embodiment, for components having substantially the same or corresponding functional configurations, the same reference numerals may be given to omit redundant descriptions. Also, for ease of understanding, the scales of the respective parts in the drawings may be different from the actual ones.

[0012] ≪FIRST EMBODIMENT≫ The non-condensable gas reduction system according to the first embodiment will be described. The non-condensable gas reduction system according to the first embodiment is used in a geothermal power plant. The geothermal power plant in which the non-condensable gas reduction system according to the first embodiment is used includes a gas-liquid separator that separates the geothermal fluid gushing out from the production well into a first gas and a first liquid, and a turbine rotated by the first gas. Further, the geothermal power plant in which the non-condensable gas reduction system according to the first embodiment is used includes a condenser that cools the first gas that has rotated the turbine and condenses the steam contained in the first gas into a second liquid. The non-condensable gas reduction system according to the first embodiment includes a pump that pressurizes a third liquid sent to a reinjection well, and an ejector. The ejector in the non-condensable gas reduction system according to the first embodiment is driven by the third liquid, attracts the non-condensable gas contained in the first gas and remaining uncondensed in the condenser, and discharges a fourth liquid in which the third liquid and the non-condensable gas are mixed. And, in the non-condensable gas reduction system according to the first embodiment, the first liquid and the fourth liquid are mixed and sent to the reinjection well. Further, in the non-condensable gas reduction system according to the first embodiment, the third liquid is a part of the cooling liquid sent to the condenser.

[0013] Next, with reference to the drawings, the non-condensable gas reduction system according to the first embodiment will be described in detail. FIG. 1 is a diagram showing an outline of the configuration of a geothermal power plant 1 including a non-condensable gas reduction system 50 which is an example of the non-condensable gas reduction system according to the first embodiment.

[0014] The geothermal power plant 1 includes a gas-liquid separator 10, a power generation unit 20, a condenser 30, a cooling unit 40, a non-condensable gas reduction system 50, and a control unit 60. The geothermal power plant 1 is a geothermal power plant using a so-called flash-type geothermal power generation method. Further, the geothermal power plant 1 includes a valve 81 and a valve 82, and a pump 91.

[0015] [Gas-liquid separator 10] The gas-liquid separator 10 separates the geothermal fluid GF ejected from the production well PWL into steam ST and hot water HW. The geothermal fluid GF ejected from the production well PWL is passed or blocked by the valve 81. The steam ST discharged from the gas-liquid separator 10 is sent to the power generation unit 20. The hot water HW discharged from the gas-liquid separator 10 is discharged to the reinjection well RWL. The pressure gauge 71 described later measures the pressure of the hot water HW.

[0016] Here, the steam ST is not pure steam but contains gases discharged from the production well PWL, such as carbon dioxide, hydrogen sulfide, etc.

[0017] [Power Generation Unit 20] The power generation unit 20 generates electricity using the steam ST. The power generation unit 20 includes a turbine 21 and a generator 22. The turbine 21 is rotated by the steam ST. More specifically, the turbine 21 rotates due to the pressure difference between the pressure of the steam ST and the pressure reduced by the condensation of the steam contained in the steam ST in the condenser 30. The generator 22 is connected to the turbine 21. When the turbine 21 rotates, the rotating shaft of the generator 22 rotates to generate electricity. The electricity generated by the generator 22 is supplied to the outside.

[0018] [Condenser 30] The condenser 30 cools the steam ST discharged from the turbine 21 with the coolant CW supplied from the cooling unit 40, more specifically, the coolant CW1. The condenser 30 is a so-called surface contact type condenser. The condenser 30 performs heat exchange between the coolant CW1 and the steam ST. By performing heat exchange between the coolant CW1 and the steam ST, the steam ST is cooled. The steam ST is condensed into water (the second liquid) by being cooled in the condenser 30. In the condenser 30 which is a surface contact type condenser, for example, the coolant CW1 flows inside the pipes in the heat exchanger, so the coolant CW1 does not come into direct contact with the steam ST.

[0019] Non-condensable gases NCG such as carbon dioxide and hydrogen sulfide contained in the steam ST accumulate at the upper part of the condenser 30. When the non-condensable gas NCG accumulates, the pressure in the condenser 30 rises. When the pressure in the condenser 30 rises, the driving force for rotating the turbine 21 decreases. When the driving force for rotating the turbine 21 decreases, the power generation efficiency in the power generation unit 20 decreases. Therefore, it is desirable to discharge the non-condensable gas NCG accumulated in the condenser 30 from the condenser 30.

[0020] In the geothermal power plant 1, the non-condensable gas NCG accumulated in the condenser 30 is attracted by the non-condensable gas reduction system 50 and discharged into the reduction well RWL.

[0021] [Cooling unit 40] The cooling unit 40 supplies the cooling liquid CW in order to cool the steam ST in the condenser 30. The cooling unit 40 is, for example, a cooling tower. The cooled cooling liquid CW1 in the cooling unit 40 is sent to the condenser 30 by the pump 91. In the condenser 30, the cooling liquid CW2 whose temperature has risen by heat exchange with the steam ST returns to the cooling unit 40 and is cooled.

[0022] [Non-condensable gas reduction system 50] The non-condensable gas reduction system 50 attracts and discharges the non-condensable gas NCG from the condenser 30. The non-condensable gas reduction system 50 includes an ejector 54, a control device 58, pressure gauges 71, 72, and 73, a valve 83, and a pump 92. The ejector 54 is driven by the cooling liquid CW, more specifically, the cooling liquid CWa which is a part of the cooling liquid CW1. The cooling liquid CWa is pressure-fed by the pump 92. The ejector 54 discharges a mixed liquid MW in which the non-condensable gas NCG and the cooling liquid CWa are mixed.

[0023] The mixed liquid MW discharged from the ejector 54 is mixed with the hot water HW and sent to the reduction well RWL. The mixed liquid MW and the hot water HW sent to the reduction well RWL are passed or blocked by the valve 82.

[0024] The structure of the ejector 54 will be described. FIG. 2 is a diagram showing an outline of the configuration of the ejector 54 included in a non-condensable gas reduction system 50, which is an example of a non-condensable gas reduction system according to the first embodiment.

[0025] The ejector 54 includes an attracting portion 51, a driving nozzle 52, and a diffuser portion 53. The attracting portion 51 has an attracting port 51a. The non-condensable gas NCG is sucked from the attracting port 51a. Further, the driving nozzle 52 is inserted into the attracting portion 51. The coolant CWa pressurized by the pump 92 is supplied to the driving port 52a of the driving nozzle 52. By discharging the high-speed coolant CWa from the tip of the driving nozzle 52, the non-condensable gas NCG present in the attracting portion 51 is discharged while being mixed with the coolant CWa. When the non-condensable gas NCG is discharged, the ejector 54 sucks the non-condensable gas NCG.

[0026] The ejector 54 mixes the non-condensable gas NCG and the coolant CWa and discharges the mixed liquid MW through the diffuser portion 53.

[0027] The mixed liquid MW in which the non-condensable gas NCG and the coolant CWa are mixed and discharged in the ejector 54 is mixed with the hot water HW and sent to the reduction well RWL.

[0028] The ejector 54 is provided on the ground. By providing the ejector 54 on the ground, the maintenance of the ejector 54 can be facilitated.

[0029] The control device 58 is configured mainly around a computer including, for example, a storage device such as a processor and a memory, an auxiliary storage device, and an input / output interface device with the outside. The processor is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an MPU (Micro Processing Unit). The control device 58 may be, for example, a programmable logic controller (PLC).

[0030] During power generation, when the pressure P1 in the pressure gauge 71 becomes higher than the pressure P2 in the pressure gauge 73, the control device 58 controls to close the valve 83 in order to prevent the hot water HW from flowing into the condenser 30. The valve 83 is provided in the flow path through which the non-condensable gas NCG between the condenser 30 and the ejector 54 flows. Note that the pressure P1 in the pressure gauge 71 is the pressure of the hot water HW, and the pressure P2 in the pressure gauge 73 is the discharge pressure of the pump 92.

[0031] Further, the control device 58 may monitor the pressure of the non-condensable gas NCG using the pressure gauge 72.

[0032] [Control Unit 60] The control unit 60 controls the entire geothermal power plant 1. The control unit 60 is mainly configured around a computer including, for example, a processor, a storage device such as a memory, an auxiliary storage device, and an input / output interface device with the outside. The processor is, for example, a CPU, a GPU, or an MPU, etc. The control unit 60 may be, for example, a programmable logic controller.

[0033] The control unit 60 controls the pump 91. When generating power, the control unit 60 controls to start the pump 91. Also, when stopping power generation, the control unit 60 controls to stop the pump 91.

[0034] Although geothermal power generation emits much less non-condensable gas than thermal power generation, it mainly emits carbon dioxide as the non-condensable gas. For example, 90% of the non-condensable gas contained in the geothermal fluid discharged from the production well is carbon dioxide. Overseas, for example, in New Zealand, there is already a carbon tax burden on the carbon dioxide emitted from geothermal power generation. Similarly in Japan, the cost of geothermal power generation may increase due to the carbon dioxide contained in the non-condensable gas.

[0035] According to the non-condensable gas reduction system according to the first embodiment, by returning the non-condensable gas to the injection well, non-condensable gases such as carbon dioxide discharged from geothermal power generation into the atmosphere can be reduced.

[0036] Further, according to the non-condensable gas reduction system according to the first embodiment, by using an ejector that is driven by a coolant to attract non-condensable gas, for example, the toxicity of hydrogen sulfide contained in the non-condensable gas to the human body and the impact on the natural environment such as the pollution of surrounding plants and soil can be reduced.

[0037] Note that the pressure gauge 71 is an example of the first pressure gauge, and the pressure gauge 73 is an example of the second pressure gauge.

[0038] ≪Second Embodiment≫ The non-condensable gas reduction system according to the second embodiment will be described. In the non-condensable gas reduction system according to the second embodiment, instead of the third liquid being a part of the coolant sent to the condenser, the third liquid is a part of the first liquid.

[0039] Next, with reference to the drawings, the non-condensable gas reduction system according to the second embodiment will be described in detail. FIG. 3 is a diagram showing an outline of the configuration of a geothermal power plant 2 including a non-condensable gas reduction system 150 which is an example of the non-condensable gas reduction system according to the second embodiment.

[0040] The geothermal power plant 2 includes a gas-liquid separator 10, a power generation unit 20, a condenser 30, a cooling unit 40, a non-condensable gas reduction system 150, and a control unit 160. The geothermal power plant 2 also includes a valve 81 and a valve 82, and a pump 91. The control unit 160 has the same functions as the control unit 60.

[0041] In the geothermal power plant 2, for the components common to the geothermal power plant 1, the description of the geothermal power plant 1 will be referred to, and the detailed description will be omitted here.

[0042] The non-condensable gas reduction system 150 pressurizes a part of the hot water HWa, which is a part of the hot water HW discharged from the gas-liquid separator 10, by the pump 92 and supplies it to the ejector 154. The non-condensable gas reduction system 150 includes an ejector 154, a control device 158, pressure gauges 71, 72, and 73, a valve 83, and a pump 92. The ejector 154 has the same configuration as the ejector 54. Also, the control device 158 has the same functions and configuration as the control device 58.

[0043] The ejector 154 is driven by the hot water HWa, which is a part of the hot water HW discharged from the gas-liquid separator 10. The hot water HWa is pumped by the pump 92. The ejector 154 discharges a mixed liquid MW obtained by mixing the non-condensable gas NCG and the hot water HWa.

[0044] The ejector 154 mixes the non-condensable gas NCG and the hot water HWa and discharges the mixed liquid MW. The mixed liquid MW in which the non-condensable gas NCG and the hot water HWa are mixed and discharged in the ejector 154 is mixed with the hot water HW and sent to the reduction well RWL.

[0045] According to the non-condensable gas reduction system according to the second embodiment, similar to the non-condensable gas reduction system according to the first embodiment, by returning the non-condensable gas to the reduction well, non-condensable gases such as carbon dioxide discharged from the geothermal power generation to the atmosphere can be reduced.

[0046] ≪Third Embodiment≫ The non-condensable gas reduction system according to the third embodiment will be described. The geothermal power plant equipped with the non-condensable gas reduction system according to the third embodiment further includes a reduction pit for storing the first liquid. And the non-condensable gas reduction system according to the third embodiment is a part of the first liquid stored in the reduction pit, instead of being a part of the coolant in which the third liquid is sent to the condenser in the non-condensable gas reduction system according to the first embodiment.

[0047] Next, with reference to the drawings, the non-condensable gas reduction system according to the third embodiment will be described in detail. FIG. 4 is a diagram showing an outline of the configuration in a geothermal power plant 3 including a non-condensable gas reduction system 250 which is an example of the non-condensable gas reduction system according to the third embodiment.

[0048] The geothermal power plant 3 includes a gas-liquid separator 10, a power generation unit 20, a condenser 30, a cooling unit 40, a non-condensable gas reduction system 250, and a control unit 260. Further, the geothermal power plant 3 includes valves 81 and 82, pumps 91 and 293, and a reduction pit 211. The control unit 260 has the same functions as the control unit 60.

[0049] In the geothermal power plant 3, for the components common to the geothermal power plant 1, the description of the geothermal power plant 1 will be referred to, and here, detailed descriptions will be omitted.

[0050] The geothermal power plant 3 includes a reduction pit 211 for storing the hot water HW discharged from the gas-liquid separator 10. The hot water HW stored in the reduction pit 211 is sent to the reduction well RWL by the pump 293. Also, a part of the hot water HW, i.e., hot water HWb, stored in the reduction pit 211 is pressurized by the pump 92 and supplied to the ejector 254. The reduction pit 211 may be a tank or a pool.

[0051] The non-condensable gas reduction system 250 includes an ejector 254, a control device 258, pressure gauges 271, 72, and 73, a valve 83, and a pump 92. The non-condensable gas reduction system 250 measures the pressure P1 of the hot water HW by the pressure gauge 271 instead of the pressure gauge 71 in the non-condensable gas reduction system 50. The ejector 254 has the same configuration as the ejector 54. Also, the control device 258 has the same functions and configurations as the control device 58. The non-condensable gas reduction system 250 pressurizes a part of the hot water HW, i.e., hot water HWb, stored in the reduction pit 211 with the pump 92 and supplies it to the ejector 254.

[0052] The ejector 254 is driven by the hot water HWb, which is a part of the hot water HW stored in the reduction pit 211. The hot water HWb is pumped by the pump 92. The ejector 254 discharges a mixed liquid MW obtained by mixing the non-condensable gas NCG and the hot water HWb.

[0053] The ejector 254 mixes the non-condensable gas NCG and the hot water HWb and discharges the mixed liquid MW. The mixed liquid MW in which the non-condensable gas NCG and the hot water HWb are mixed and discharged in the ejector 254 is mixed with the hot water HW and sent to the reduction well RWL.

[0054] According to the non-condensable gas reduction system according to the third embodiment, similar to the non-condensable gas reduction system according to the first embodiment, by returning the non-condensable gas to the reduction well, non-condensable gases such as carbon dioxide discharged from geothermal power generation into the atmosphere can be reduced.

[0055] ≪Determination of Dissolution of Non-Condensable Gas in Non-Condensable Gas Reduction System According to Embodiment of the Present Disclosure≫ In the non-condensable gas reduction system according to the embodiment of the present disclosure, the determination of the dissolution of the non-condensable gas in the mixed liquid discharged by the ejector will be described. In the mixed liquid discharged from the ejector, it is desirable that the non-condensable gas is completely dissolved in the third liquid. Therefore, a method for determining whether the non-condensable gas is dissolved in the third liquid will be described.

[0056] Each of FIGS. 5 and 6 is a diagram for explaining the determination of the dissolution of the non-condensable gas in the non-condensable gas reduction system according to the embodiment of the present disclosure. In the following description, the ejector 54 will be used for explanation. The same applies when the ejector 154 or the ejector 254 is used instead of the ejector 54.

[0057] A tank 355 is provided downstream of the ejector 54. A level meter 374 is installed in the tank 355. The level meter 374 measures the level of the liquid stored in the tank 355. The measured result is output to the control device 358. The control device 358 executes the determination of the dissolution of the non-condensable gas NCG.

[0058] As shown in FIG. 6(A), in the mixed liquid MW, when the non-condensable gas NCG is completely dissolved, the inside of the tank 355 is filled with the mixed liquid MW. On the other hand, as shown in FIG. 6(B), in the mixed liquid MW, when the non-condensable gas NCG is not completely dissolved, the non-condensable gas NCG accumulates in the upper part of the tank. Therefore, when the non-condensable gas NCG accumulates, the height measured by the level gauge 374 becomes lower by the height ΔL. Therefore, by measuring the level of the mixed liquid MW in the tank 355 using the level gauge 374, it is possible to determine the dissolution of the non-condensable gas NCG in the mixed liquid MW.

[0059] Here, the processing when the non-condensable gas NCG is not dissolved will be described. FIG. 7 is a diagram for explaining a first example of the processing when the non-condensable gas is not dissolved in the non-condensable gas reduction system according to the embodiment of the present disclosure. When the control device 458 determines that the non-condensable gas NCG is not dissolved based on the measurement result of the level in the level gauge 374, the control device 458 opens the valve 356 provided in the pipe connecting the tank 355 and the ejector 54. By opening the valve 356, the non-condensable gas NCG is sucked from the ejector 54.

[0060] Also, another example will be described. FIG. 8 is a diagram for explaining a second example of the processing when the non-condensable gas is not dissolved in the non-condensable gas reduction system according to the embodiment of the present disclosure. In the second example, an additional ejector 550 is further provided. And a pump 557 for supplying a driving flow to the ejector 550 is provided. The non-condensable gas NCG accumulated in the tank 355 is discharged from an ejector 550 different from the ejector 54. When the control device 558 determines that the non-condensable gas NCG is not dissolved based on the measurement result of the level in the level gauge 374, the control device 558 opens the valve 556, starts the pump 557, and uses the ejector 550 to suck the non-condensable gas NCG in the tank 355. The ejector 550 discharges the mixed liquid MW in which the non-condensable gas NCG is mixed into the reduction well RWL.

[0061] Furthermore, another example will be described. FIG. 9 is a diagram for explaining a third example of the process when the non-condensable gas is not dissolved in the non-condensable gas reduction system according to an embodiment of the present disclosure. In the third example, a tank 656 for storing a chemical agent is provided. The chemical agent is, for example, an alkaline agent. When the control device 658 determines that the non-condensable gas NCG is not dissolved based on the measurement result of the level in the level meter 374, the control device 658 opens the valve 659 between the tank 355 and the tank 656 to inject the chemical agent into the tank 355. The chemical agent is, for example, sprayed or introduced from the upper part of the tank 355.

[0062] The above examples may be appropriately combined in each of the non-condensable gas reduction systems according to the first to third embodiments.

[0063] The control devices 358, 458, 558, and 658 have the functions of the control device in the non-condensable gas reduction system according to the first to third embodiments.

[0064] <<Fourth Embodiment>> The non-condensable gas reduction system according to the fourth embodiment will be described. The non-condensable gas reduction system according to the fourth embodiment includes a plurality of ejectors in the non-condensable gas reduction system according to the first embodiment.

[0065] Next, with reference to the drawings, the non-condensable gas reduction system according to the fourth embodiment will be described in detail. FIG. 10 is a diagram showing a schematic configuration of a geothermal power plant 4 including a non-condensable gas reduction system 750 which is an example of the non-condensable gas reduction system according to the fourth embodiment.

[0066] The geothermal power plant 4 includes a gas-liquid separator 10, a power generation unit 20, a condenser 30, a cooling unit 40, a non-condensable gas reduction system 750, a control unit 760, and a pump 91.

[0067] In the geothermal power plant 4, for the components common to the geothermal power plant 1, the description of the geothermal power plant 1 will be referred to, and here, the detailed description will be omitted.

[0068] The non-condensable gas reduction system 750 includes a plurality of ejectors 54, a control device 758, pressure gauges 71, 72, and 73, a valve 83, and a pump 92. By including a plurality of ejectors 54, the non-condensable gas reduction system 750 includes a plurality of lines including the ejectors 54 in parallel. By including a plurality of lines including the ejectors 54 in parallel, maintenance of the ejectors 54 can be performed without stopping the entire non-condensable gas reduction system 750 by operating some of the lines.

[0069] According to the non-condensable gas reduction system according to the fourth embodiment, similar to the non-condensable gas reduction system according to the first embodiment, by returning the non-condensable gas to the reinjection well, non-condensable gases such as carbon dioxide discharged from geothermal power generation to the atmosphere can be reduced. Further, according to the non-condensable gas reduction system according to the fourth embodiment, by providing a plurality of ejectors, for example, by switching and operating, maintainability can be improved.

[0070] In the example of FIG. 10, a geothermal power plant 4 having the same configuration as the geothermal power plant 1 including the non-condensable gas reduction system 50 which is an example of the non-condensable gas reduction system according to the first embodiment was used as an example for explanation, but it is not limited to the non-condensable gas reduction system according to the first embodiment. Similarly, a geothermal power plant including the non-condensable gas reduction system according to the second or third embodiment may include a plurality of lines including ejectors. Further, in the non-condensable gas reduction system according to the fourth embodiment, the above-described processing when the non-condensable gas is not dissolved may be performed. The same applies to the following embodiments.

[0071] ≪Fifth Embodiment≫ The non-condensable gas reduction system according to the fifth embodiment will be described. In the non-condensable gas reduction system according to the fifth embodiment, instead of the third liquid being a part of the coolant sent to the condenser, the third liquid is a liquid containing the second liquid.

[0072] Next, with reference to the drawings, the non-condensable gas reduction system according to the fifth embodiment will be described in detail. FIG. 11 is a diagram showing an outline of the configuration of a geothermal power plant 5 including a non-condensable gas reduction system 850 which is an example of the non-condensable gas reduction system according to the fifth embodiment.

[0073] The geothermal power plant 5 includes a gas-liquid separator 10, a power generation unit 20, a condenser 30, a cooling unit 40, a non-condensable gas reduction system 850, and a control unit 860. The geothermal power plant 5 also includes a valve 81 and a valve 82, and a pump 91. The control unit 860 has the same functions as the control unit 60.

[0074] Regarding the common configuration between the geothermal power plant 5 and the geothermal power plant 1, the description of the geothermal power plant 1 will be referred to, and here, detailed description will be omitted.

[0075] The non-condensable gas reduction system 850 pressurizes the condensate HWc (second liquid) of the steam ST in the condenser 30 by a pump 92 and supplies it to an ejector 854. The non-condensable gas reduction system 850 includes an ejector 854, a control device 858, pressure gauges 71, 72, and 73, a valve 83, and a pump 92. The ejector 854 has the same configuration as the ejector 54. Also, the control device 858 has the same functions and configuration as the control device 58.

[0076] The ejector 854 is driven by the condensate HWc of the steam ST in the condenser 30. The condensate HWc is pumped by a pump 92. The ejector 854 discharges a mixed liquid MW in which the non-condensable gas NCG and the condensate HWc are mixed.

[0077] The ejector 854 mixes the non-condensable gas NCG and the condensate HWc and discharges the mixed liquid MW. The mixed liquid MW in which the non-condensable gas NCG and the condensate HWc are mixed and discharged in the ejector 854 is mixed with the hot water HW and sent to the reduction well RWL.

[0078] According to the non-condensable gas reduction system according to the fifth embodiment, similar to the non-condensable gas reduction system according to the first embodiment, by returning the non-condensable gas to the reinjection well, non-condensable gases such as carbon dioxide discharged from the geothermal power generation to the atmosphere can be reduced.

[0079] ≪Sixth Embodiment≫ The non-condensable gas reduction system according to the sixth embodiment will be described. The non-condensable gas reduction system according to the sixth embodiment is such that, instead of the third liquid being part of the coolant sent to the condenser in the non-condensable gas reduction system according to the first embodiment, the third liquid contains the second liquid and is part of the coolant sent to the condenser.

[0080] Next, with reference to the drawings, the non-condensable gas reduction system according to the sixth embodiment will be described in detail. FIG. 12 is a diagram showing an outline of the configuration of a geothermal power plant 6 including a non-condensable gas reduction system 950 which is an example of the non-condensable gas reduction system according to the sixth embodiment.

[0081] The geothermal power plant 6 includes a gas-liquid separator 10, a power generation unit 20, a condenser 930, a cooling unit 940, a non-condensable gas reduction system 950, and a control unit 960. The geothermal power plant 6 also includes a valve 81 and a valve 82, and a pump 91 and a pump 932. The control unit 960 has the same functions as the control unit 60.

[0082] In the geothermal power plant 6, for the components common to the geothermal power plant 1, the description of the geothermal power plant 1 will be referred to, and here, detailed description will be omitted.

[0083] [Condenser 930] The condenser 930 cools the steam ST discharged from the turbine 21 by the cooling liquid CWA, more specifically the cooling liquid CWA1, supplied from the cooling section 940. The condenser 930 is a so-called direct contact type condenser. The condenser 930 includes a nozzle section 931. The nozzle section 931 includes a plurality of nozzles that spray the cooling liquid CWA1 as mist. Note that the number of nozzles included in the nozzle section 931 may be one. The condenser 930 performs heat exchange with the steam ST by spraying the cooling liquid CWA1 onto the steam ST for direct contact. By performing heat exchange between the cooling liquid CWA1 and the steam ST, the steam ST is cooled. The steam ST is cooled in the condenser 930 and condenses into water (the second liquid). In the condenser 930 which is a direct contact type condenser, the cooling liquid CWA1 comes into direct contact with the steam ST. The cooling liquid CWA2 contains the water (the second liquid) obtained by condensing the steam ST.

[0084] [Cooling section 940] The cooling section 940 supplies the cooling liquid CWA to cool the steam ST in the condenser 930. The cooling section 940 is a cooling tower. The pump 932 sends the cooling liquid CWA2, which has been heated to a high temperature by cooling the steam ST in the condenser 930, to the cooling section 940. The cooling section 940 cools the cooling liquid CWA2. The cooled cooling liquid CWA in the cooling section 940 is sent to the condenser 930 by the pump 91. In the condenser 930, the cooling liquid CWA2, whose temperature has risen by heat exchange with the steam ST, returns to the cooling section 40 to be cooled.

[0085] The cooling section 940 is a forced draft wet cooling tower. The cooling section 940 brings the cooling liquid CWA2 into direct contact with air. Then, the cooling section 940 cools the cooling liquid CWA2 by the latent heat of evaporation and sensible heat transfer of the cooling liquid CWA2 when the cooling liquid CWA2 is brought into direct contact with air. The cooling section 940 is an induced counterflow type cooling tower.

[0086] The cooling unit 940 includes a fan 941, a nozzle unit 942, and a packing material 943. The fan 941 discharges the outside air taken in from the opening 940h to the inside. The nozzle unit 942 includes a plurality of nozzles that spray the coolant CWA2 sent from the condenser 930 as mist onto the packing material 943. Note that the nozzle unit 942 may include one nozzle.

[0087] As air passes through the packing material 943, the coolant CWA2 sprayed from the nozzle unit 942 exchanges heat with the air.

[0088] The coolant CWA cooled in the cooling unit 940 is supplied to the condenser 930 by the pump 91.

[0089] In the above example, the case where the cooling unit 940 is a suction type counterflow cooling tower has been described. However, the cooling unit of the non-condensable gas reduction system according to the present embodiment is not limited to a suction type counterflow cooling tower. For example, the cooling unit of the non-condensable gas reduction system according to the present embodiment may be a forced type counterflow cooling tower, a suction type crossflow cooling tower, or a forced type crossflow cooling tower. Further, the cooling unit of the non-condensable gas reduction system according to the present embodiment may be a natural ventilation type cooling tower.

[0090] [Non-condensable gas reduction system 950] The non-condensable gas reduction system 950 attracts and discharges the non-condensable gas NCG from the condenser 930. The non-condensable gas reduction system 950 is driven by the coolant CWA, more specifically, the coolant CWAa which is a part of the coolant CWA1. The coolant CWAa is pumped by the pump 92. The ejector 954 discharges a mixed liquid MW in which the non-condensable gas NCG and the coolant CWAa are mixed. The non-condensable gas reduction system 950 includes an ejector 954, a control device 958, pressure gauges 71, 72, and 73, a valve 83, and a pump 92. The ejector 954 has the same configuration as the ejector 54. Further, the control device 958 has the same functions and configuration as the control device 58.

[0091] The ejector 954 is driven by the coolant CWAa which is part of the coolant CWA1. The coolant CWAa contains water (the second liquid) in which the steam ST has condensed in the condenser 930. The coolant CWAa is pumped by the pump 92. The ejector 954 discharges a mixture MW obtained by mixing the non-condensable gas NCG and the coolant CWAa.

[0092] The ejector 954 mixes the non-condensable gas NCG and the coolant CWAa and discharges the mixture MW. The mixture MW in which the non-condensable gas NCG and the coolant CWAa are mixed and discharged in the ejector 954 is mixed with the hot water HW and sent to the reinjection well RWL.

[0093] According to the non-condensable gas reduction system according to the sixth embodiment, similar to the non-condensable gas reduction system according to the first embodiment, by returning the non-condensable gas to the reinjection well, non-condensable gases such as carbon dioxide discharged from the geothermal power generation to the atmosphere can be reduced.

[0094] It should be considered that all the embodiments disclosed this time are illustrative in all respects and not restrictive. The above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and gist of the appended claims.

Explanation of Reference Numerals

[0095] 1, 2, 3, 4, 5, 6 Geothermal power plants 10 Gas-liquid separator 20 Power generation unit 21 Turbine 22 Generator 30, 930 Condensers 40, 940 Cooling units 50, 150, 250, 750, 850, 950 Non-condensable gas reduction systems 51 Induction section 51a Induction port 52 Driving nozzle 52a Driving port 53 Diverging section 54, 154, 254, 550, 854, 954 Ejectors Control devices 58, 158, 258, 358, 458, 558, 658, 758, 858, 958 Control units 60, 160, 260, 760, 860, 960 Pressure gauges 71, 72, 73, 271 Valves 81, 82, 83, 356, 556, 659 Pumps 91, 92, 293, 557, 932 Reduction pit 211 Tanks 355, 656 Level gauge 374 Cooling liquids CW, CW1, CW2, CWa, CWA, CWA1, CWA2, CWAa Geothermal fluid GF Hot water HW, HWa, HWb Condensate HWc Mixture MW Non-condensable gas NCG Production well PWL Reduction well RWL Steam ST

Claims

1. A non-condensable gas reduction system for use in a geothermal power plant, comprising: a gas-liquid separator that separates a geothermal fluid emerging from a production well into a first gas and a first liquid; a turbine that is rotated by the first gas; and a condenser that cools the first gas that rotates the turbine and condenses steam contained in the first gas into a second liquid, A pump for pressurizing the third liquid sent to the reinjection well; a plurality of ejectors that are driven by the third liquid, attract non-condensable gas that is contained in the first gas and remains uncondensed in the condenser, and discharge a fourth liquid that is a mixture of the third liquid and the non-condensable gas; A plurality of lines including any one of the plurality of ejectors and arranged in parallel; Equipped with The first liquid and the fourth liquid are mixed and sent to the injection well. Non-condensable gas reduction system.

2. The third liquid is a portion of the cooling liquid sent to the condenser. The noncondensable gas reduction system of claim 1 .

3. The third liquid is a part of the first liquid. The noncondensable gas reduction system of claim 1 .

4. The geothermal power plant further comprises a reduction pit for storing the first liquid; The third liquid is a portion of the first liquid stored in the reduction pit. The noncondensable gas reduction system of claim 1 .

5. The third liquid includes the second liquid. The noncondensable gas reduction system of claim 1 .

6. The third liquid is a portion of the cooling liquid sent to the condenser which contains the second liquid. The noncondensable gas reduction system of claim 1 .

7. The ejector is installed on the ground. The non-condensable gas reduction system according to any one of claims 1 to 6.

8. a tank connected downstream of the ejector; a level meter for measuring the level of the liquid stored in the tank; A control device, The control device performs a determination of dissolution of the non-condensable gas in the fourth liquid according to the level measured by the level meter. The non-condensable gas reduction system according to any one of claims 1 to 6.

9. When the control device determines that the non-condensable gas is not dissolved in the fourth liquid, the control device controls the ejector to discharge the non-condensable gas accumulated in the tank. The noncondensable gas reduction system of claim 8.

10. When the control device determines that the non-condensable gas is not dissolved in the fourth liquid, the control device controls the non-condensable gas accumulated in the tank to be discharged from another ejector different from the ejector to the reinjection well. The noncondensable gas reduction system of claim 8.

11. When the control device determines that the non-condensable gas is not dissolved in the fourth liquid, the control device controls to inject a chemical into the tank. The noncondensable gas reduction system of claim 8.

12. a first pressure gauge that measures a pressure of the first liquid; a second pressure gauge that measures the pressure of the third liquid; a valve provided in a flow path between the condenser and the ejector; A control device, The control device closes the valve when a pressure of the first liquid measured by the first pressure gauge is higher than a pressure of the third liquid measured by the second pressure gauge. The non-condensable gas reduction system according to any one of claims 1 to 6.

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