Power plant

Abstract

To provide a power plant having a large synergistic effect by combining a solid polymer type water electrolysis device, a steam turbine plant, and a gas turbine cycle by hydrogen / oxygen combustion.SOLUTION: A section on a feed water pipeline of a steam turbine plant corresponding to pressure and temperature conditions of a gas turbine and a solid polymer type water electrolysis device is selected, a feed water circulation path including the solid polymer type water electrolysis device and a feed water heater is provided, and heat generated by water electrolysis of the solid polymer type water electrolysis device is absorbed by the feed water heater and used for heating boiler feed water.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This project is about a power plant with a large synergistic effect that combines a solid polymer water electrolysis device, a steam turbine plant, and a gas turbine cycle using hydrogen-oxygen combustion. [Background technology]

[0002] A type of technology known as a combined plant, which combines a steam turbine power plant with a desalination system, is known. The basic configuration of this plant is a combination of a steam turbine and an evaporative desalination system (such as MSF), and the exhaust gas from the steam turbine is used as a heat source for the MSF to desalinate seawater.

[0003] MSF has issues such as huge construction costs, high energy consumption, and the need for chemical injections, which means high maintenance costs.Even when combined with a steam turbine power plant, it is said that its energy consumption is several times higher than that of the competing reverse osmosis method of seawater desalination.

[0004] On the other hand, reverse osmosis produces wastewater with a much higher salt concentration than evaporation, so care must be taken when discharging it from a single plant. For example, if the raw water is seawater with a salt content of 3.5%, and the water recovery rate is 50%, the salt concentration of the wastewater will be 7%. If seawater with a salt content of 7% is directly discharged into the ocean, the oxygen concentration in the depths will decrease, which is said to have a serious impact on the marine ecosystem.

[0005] Patent Document 1 proposes a system that combines steam turbine power generation with MSF and reverse osmosis, and is configured to simultaneously supply water for multiple purposes, such as drinking water for people, irrigation water, and animal drinking water. However, there is a problem in that a thermal power plant using MSF and a deaerator is also used, which requires chemical injection and results in high maintenance costs.

[0006] Non-Patent Document 1 is a research report on the utilization of heat generated from solid polymer water electrolysis equipment, and introduces a study on improving energy efficiency by utilizing heat at 50-80°C, which is normally dissipated into the atmosphere by a cooling tower, for district heat supply, etc. The issue is whether there is a need for heat utilization near the solid polymer water electrolysis equipment.

[0007] Non-Patent Document 2, page 3, contains an illustration of an oxygen-hydrogen combustion turbine power generation system and an explanation of the system. According to the explanation, "By using steam generated by direct combustion as feedwater, a completely new closed system that integrates the Rankine cycle and Brayton cycle is realized, achieving high efficiency." The research appears to be based on the premise that hydrogen will be transported from overseas by hydrogen carrier, and oxygen will be obtained separately from the atmosphere using a cryogenic separation method. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Special Publication No. 49-49114 [Patent Document 2] Patent No. 4084014 [Non-patent literature]

[0009] [Non-Patent Document 1] Utilization of waste heat from PEM electrolyzer, Els van der Roest et al., International Journal of Hydrogen Energy, Volume 48, Issue 72, 2023 [Non-patent document 2] Research and Development of Common Fundamental Technologies for Oxygen-Hydrogen Combustion Turbine Power Generation, Presenter: Norihiko Iki, NEDO Hydrogen and Fuel Cell Results Reporting Session 2022, P3, P4, P6, Presentation No. D-1, July 29, 2022 Summary of the Invention [Problem to be solved by the invention]

[0010] The objective of this project is to provide a power plant with a large synergistic effect by combining a solid polymer water electrolysis device, a steam turbine plant, and a gas turbine cycle using hydrogen-oxygen combustion. [Means for solving the problem]

[0011] The first aspect of the present invention is a water electrolysis device, a solid polymer water electrolysis device including a hydrogen separation vessel and an oxygen separation vessel; A boiler, a feedwater, a feedwater heater, a steam turbine, a condenser, a high-temperature medium flow path and a low-temperature medium flow path through which the feedwater flows, both of which are provided inside the feedwater heater; It consists of The low-temperature medium flow path communicates with a first purification device provided in a water supply line upstream thereof; The effluent water originating from the hydrogen separation vessel is The high-temperature medium is passed through the high-temperature medium passage of the feedwater heater, cooled by the feedwater, and treated in a second purification device. Heading to The pipeline is configured as follows: The effluent water originating from the oxygen separation vessel is The hot medium is passed through another hot medium passage of the feedwater heater, cooled by the feedwater, and treated in a third purification device. Heading to The pipeline is configured as follows: The power plant is provided with a pipeline that connects the low-temperature medium flow path to the solid polymer water electrolysis device.

[0012] The second invention of the present invention is In the first aspect of the present invention, A relay means is provided, the relay means being made of a housing; The relay means has a space above it. (hereinafter referred to as the upper space) , has a water supply reservoir at the bottom, A pressure reducing means is provided in the upper space, The water supply reservoir, The low-temperature medium flow path and the first to third purification devices are connected to each other. a throttle means is provided between the hydrogen separation vessel and the high-temperature medium flow path; a throttle means is provided between the oxygen separation vessel and the separate high-temperature medium flow path; The power plant further comprises a feedwater pump disposed in a pipe connected adjacent to the low-temperature medium flow path.

[0013] The third invention of the present invention is In the first aspect of the present invention, a pressure balancing means for controlling a pressure in a hydrogen gas pipeline and a pressure in an oxygen gas pipeline of the solid polymer water electrolysis device so as to balance the pressure therebetween, a hydrogen gas pipeline and an oxygen gas pipeline are provided to connect the solid polymer water electrolysis device and the hydrogen-oxygen combustor; The power plant includes a gas turbine, and is provided with an extraction pipe connecting the extraction port provided in the steam turbine and the hydrogen-oxygen combustor.

[0014] The fourth aspect of the present invention is In the third invention, The hydrogen-oxygen combustor is provided in a single stage, and the gas turbine is provided in a single stage, the hydrogen-oxygen combustor is disposed upstream of the gas turbine; The power plant has an exhaust outlet of the gas turbine connected to another feedwater heater or steam generator of the steam turbine plant.

[0015] The fifth aspect of the present invention is In the third invention, The hydrogen-oxygen combustor and the gas turbine are both provided with n stages (n is a number equal to or greater than 2), The hydrogen-oxygen combustors in each stage are located upstream of the gas turbines in each stage, The n-1 stage gas turbine is located upstream of the n stage hydrogen-oxygen combustor; A power plant in which an exhaust outlet of an n-th stage gas turbine is connected to another feedwater heater or steam generator of the steam turbine plant.

[0016] The sixth aspect of the present invention is In the first aspect of the present invention, The first, second and third purification units are power plants consisting of degassing membranes and continuous electrically regenerated ion exchange membranes.

[0017] The seventh aspect of the present invention is In the first aspect of the present invention, The power plant has the first purification device inlet connected to a hot well provided below the condenser via a transfer pump.

[0018] The eighth aspect of the present invention is In the first aspect of the present invention, The feedwater treated in the first purification device is permeated water that has been desalinated in a reverse osmosis membrane module, The power plant includes a power plant in which the temperature of the feedwater heater is raised to a predetermined temperature by drain discharged from another feedwater heater provided adjacent to the feedwater heater on the downstream side. [Effects of the Invention]

[0019] According to the power plant of the present invention, the heat generated by water electrolysis can be effectively used to heat the boiler feed water. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic overall configuration diagram of a power plant according to an embodiment; [Figure 2] FIG. 10 is a detailed schematic diagram showing another embodiment of a circulation path including a solid polymer water electrolysis apparatus and a feedwater heater. [Figure 3] FIG. 1 is a basic schematic diagram illustrating gas-side pressure balance control and feedwater circulation control of a solid polymer water electrolysis apparatus. [Figure 3-1] FIG. 1 is a schematic system diagram showing the relationship between pressure-balanced water electrolysis and a single-stage gas turbine cycle. [Figure 3-2] FIG. 1 is a schematic diagram showing the relationship between pressure-balanced water electrolysis and an n-stage gas turbine cycle. [Figure 4]10 is a schematic diagram showing another embodiment of the flow of the supply water. FIG. [Figure 5] FIG. 10 is a schematic diagram showing another example of the relative positions of the feedwater pump and the feedwater heater. [Figure 6] FIG. 5 is a schematic diagram showing another embodiment of FIG. 4 in which the position of the water supply pump is changed. DETAILED DESCRIPTION OF THE INVENTION

[0021] Preferred embodiments of the present invention will be described below, but the present invention can be implemented in many different forms and is not limited to the following embodiments as long as they satisfy the key points of the present invention.

[0022] In the present embodiment, two types of paths for the flow of the working medium are provided. The open system uses seawater as raw water and transfers the ultrapure water condensed in the condenser to the subsequent process. It is a closed system in which condensate is circulated internally.

[0023] (Working medium flow - overall, overview, Figure 1) (open system) The route from the raw water intake 12 to the inlet of the purification device PF1 is specific to the open system, and the route thereafter is the same as that of the closed system. The working medium from the raw water intake 12 to the inlet of the high-pressure reverse osmosis membrane 14 is called raw water, and the working medium flowing in the section from the high-pressure reverse osmosis membrane outlet 31 to the inlet of boiler B of the steam generator 1 is called boiler feedwater or simply feedwater. After boiler B, the working medium undergoes various processes to become superheated steam, saturated steam, and wet steam, which then flows into the condenser where it becomes saturated water and is collected in the hot well 7w located below the condenser. The water produced in the condenser is called condensed water, condensed water, or ultrapure water.

[0024] (Working medium flow - overall, overview, Figure 1) (closed system) The closed system recirculation line in this embodiment is a line connecting XX below the hot well 7w of the condenser 7 and XX at the inlet of the purification unit PF1, and is configured so that switching from the open system to the closed system is performed by closing the stop valve 52 provided near the low-pressure reverse osmosis membrane outlet 41. The lines after the purification unit PF1 in the closed system are the same as those in the open system. Regarding the positional relationship on the feedwater pipeline, downstream refers to the boiler side, and upstream refers to the opposite direction. Regarding the flow direction of the working medium, the direction of the source of the flow is considered to be upstream.

[0025] (Flow of working medium - up to desalination, open system, Figure 1) Seawater (salinity 3.5%) is pumped up by a cooling seawater pump SP driven by a motor M1 and flows into the heat exchanger 7he of the condenser 7. The cooling seawater receives heat of condensation from the working medium via the heat exchanger 7he, is heated by, for example, 5°C, and is discharged into a cooling seawater outlet pipe 11 connected to the heat exchanger 7he. The raw water for the water supply is taken from an opening 12 provided in the piping 11 and flows through the raw water pipeline 9. LP1 → raw water heater FWH6 → ultrafiltration membrane 13 → high-pressure pump HP1 → permeate water outlet 31 of high-pressure reverse osmosis membrane 14 → check valve 75 → permeate water outlet 41 of low-pressure reverse osmosis membrane 40 Follow this route.

[0026] (Working medium flow - desalination process, Figure 1) The high-pressure reverse osmosis membrane 14 produces pure water that can be used as drinking water, but the boron content must be adjusted for drinking water, and the low-pressure reverse osmosis membrane 40 performs this function, separating the water into permeated water, i.e., boron-removed water 41, and concentrated wastewater 32 with a pressure head. The low-pressure reverse osmosis membrane 40 is capable of removing silica in addition to boron, and as a reverse osmosis membrane, it is also capable of removing electrolytes, and therefore functions as a pre-processing step for the next purification step, i.e., the ultrapure water process. The wastewater 32 from the low-pressure reverse osmosis membrane 40, which is enriched with boron, is configured to have a pressure head and flows into the water turbine HT2, driving the low-pressure pump LP1. In this embodiment, the wastewater 32 leaving the water turbine HT2 is discharged into the wastewater collection pipe 27.

[0027] (Energy saving and mechanical energy recovery, Figure 1) The energy consumed by the reverse osmosis membrane is mostly the power of the high-pressure pump for reverse osmosis and the pressure energy of the concentrated seawater that is discarded at high pressure, out of the power of the pumps used for raw water intake, pre-treatment (not shown), the reverse osmosis membrane, etc. In this embodiment, a simple Pelton water turbine and pump combination is used to recover the pressure energy.

[0028] The reason why the temperature of the raw water is raised by the raw water heater FWH6 is to lower the viscosity coefficient of the raw water and thereby reduce the flow resistance of the high-pressure pump. The reason why the raw water is obtained from the cooled seawater discharged from the condenser 7 is the same. In the HT1=HP1=M2 train, the high-pressure pump HP1 is axially connected to the water turbine HT1, which serves as an energy recovery device, and is further connected to the motor M2. Approximately 50% of the power required for the high-pressure pump HP1 is recovered by the water turbine HT1. Note that the symbol = in the train does not mean equality, but rather indicates axial connection.

[0029] (Switching to a closed system, combined use of open and closed systems, Figure 1) When the raw water intake is temporarily shut off, a stop valve 52 provided between the low-pressure reverse osmosis membrane outlet 41 and the purification unit PF1 is shut off. At the same time, a control signal is generated to stop the low pressure pump LP1 and the high pressure pump HP1. At the same time as the control signal, the stop valve 52 provided in the communication pipe 8 at the bottom of the condenser is opened. A control signal is issued to activate the pump LPx, The water stored in the condenser flows into the purification unit PF1 via the pipe XX-XX. Open and closed combined operation is also possible. The double stop valve 52 is opened to start the low-pressure pump LP1, the low-pressure pump LPx, and the high-pressure pump HP1, and the raw water flow rate is controlled by the electric motor M2 linked to the high-pressure pump HP1 and the opening of the throttle valve 72 provided on the outlet side of the high-pressure pump HP1.

[0030] (Purpose of using ultrapure water) In this embodiment, the purpose is to use the extracted steam from the second stage steam turbine of a two-stage steam turbine as dilution steam to combust hydrogen gas and oxygen gas, generate gas at a temperature of 1400°C to 1600°C, and introduce it into an internal combustion type ultra-high temperature turbine, i.e., a gas turbine, to construct a combined cycle. In view of this purpose, ultrapure water is used as the working medium to prevent high-temperature oxidation of heat-resistant metals and erosion corrosion caused by alkaline ash.

[0031] (Refining unit PF1, Figure 1, Figure 2) In the purification unit PF1, the feedwater flowing in from upstream is treated by a degassing membrane GTM1, which has a deoxygenation function, and then deionized by a continuous electric ion exchange membrane EDI, completing the ultrapure water treatment. GTM and EDI are both commonly used names. The purification unit PF1 replaces the conventional degassing unit. The gas components such as carbon dioxide and oxygen gas separated from water by the membrane in the GTM1 are released via a flue 30 using a pressure reducing means VP. teeth The seawater is passed through an ultrafiltration membrane followed by pre-treatment with high pressure reverse osmosis, low pressure reverse osmosis and GTM before being led to the EDI1. In the EDI 1, a small amount of electrode system wastewater 28 is constantly discharged into the pipe 27. In addition, about 10% of the water supplied to the EDI is discharged as a deionized concentrated solution, but by returning the concentrated solution to the inlet of the high-pressure pump HP1 in Figure 1, 99.6% of the concentrated substances are removed and all of the water is recovered (not shown).

[0032] (Relay means 2, Figures 1 to 3, Figures 4 to 6) The ultrapure water leaving the purification unit PF1 flows into the relay means 2. In this embodiment, the feed water flows out from the high-pressure reverse osmosis membrane with a pressure head and reaches the relay means 2 without using a so-called intermediate tank. The relay means 2 is made of a housing, has a space at the top and a water supply reservoir 2a at the bottom, A pressure reducing means VP is provided in the upper space, the feedwater flows into the lower part of the feedwater reservoir 2a from a feedwater pipe provided upstream of the relay means 2, and water flowing through a hydrogen pipe 95 and an oxygen pipe 94, which have the same purity as the purified feedwater, flow into the lower part of the feedwater reservoir 2a. A pipe is provided that connects the low-temperature medium flow path of the feedwater heater FWHP to the solid polymer water electrolysis device, and a feedwater pump FP1 is disposed in the pipe connected adjacent to the low-temperature medium flow path. Heading to The pressure of the water supply is sufficient to perform pressurized water electrolysis.

[0033] Regarding the position of the feed water pump and the pipeline from the relay means 2 to the solid polymer water electrolysis device via the low temperature medium flow path, other than the configuration shown in Fig. 1 , a configuration in which the feed water pump is changed to a position as shown in Fig. 5 or a configuration in which the flow discharged from the low temperature medium flow path is separated into two as shown in Fig. 6 is also possible. Other variations are possible, but are within the scope of the present invention as long as the gist of the invention is the same. The temperature of each ultrapure water flowing into the relay means 2 is 35°C to 40°C, and the pressure P in the upper space is adjusted by the pressure reducing means VP so as to be equivalent to the saturated pressure of water at that temperature. differenceThe pressure reducing means may be a steam ejector or a vacuum pump, but in the present embodiment, a vacuum pump is used.

[0034] (Circulation path, solid polymer water electrolysis device, Figures 1 to 3, Figures 4 to 6) In FIG. 1, the solid polymer water electrolysis device Heading to The feed water, i.e., the fuel water (ultrapure water used in the electrolysis reaction among the feed water) and the circulating cooling water, reaches point 5 and is divided into two, namely, pipe 91 and pipe 92. The flow rates are adjusted by throttle valves 72a and 72b, respectively. The feed water that has passed through the throttle valve 72a flows into the upper part of the reservoir 55a of the container 55 having an oxygen separation function and containing the water electrolysis device. The feed water that has passed through 72b flows directly into stack 57, which is made up of electrolytic cells that constitute the water electrolysis device.

[0035] Inside it, it is used for cooling and electrolysis, Oxygen gas 60 (air bubbles in FIG. 1) is discharged from the top of the stack 57 together with water into the reservoir 55a. In FIG. 1, RCT is a rectifier that converts AC to DC, and is a DC power supply device for water electrolysis. Together with the stack 57, it functions as a water electrolysis device. The ultrapure water flowing into the upper part of the stored water reservoir 55a descends while exchanging heat with the stored water, cools the stack 57 from the outside, and is then discharged into the pipe 94 system, that is, the oxygen system pipe. The oxygen gas has accompanying moisture removed in the demister 6 and flows out into the pipe 53, where it is used in the gas turbine cycle described below. The moisture separated by the demister falls and joins the stored water. The discharged water contains minute amounts of dissolved oxygen along with fine oxygen gas bubbles, and is also said to contain hydrogen gas due to cross-penetration in the stack 57, although the amount is below the explosive limit.

[0036] Meanwhile, hydrogen gas produced by electrolysis in the stack flows together with cooling water through pipe 51 into hydrogen separation vessel 58 where it is separated into gas and liquid. The hydrogen gas then flows upward and has accompanying moisture removed in demister 6 before flowing out into pipe 53 and being used in the gas turbine cycle, which will be described later. The moisture separated and collected in reservoir 58a is discharged into pipe 95, i.e., the hydrogen system pipe.

[0037] (Feedwater heater FWHP, Figure 1, Figure 2) The FWHP can be considered as a single three-fluid heat exchanger, or as two parallel two-fluid heat exchangers, HE94 and HE95. In either case, the flow paths for the three fluids are independent and internal leakage is not permitted. The outflow waters discharged from the solid polymer water electrolysis system at a temperature of about 80°C to 90°C through the pipes 94 and 95 pass through throttling means 72ow and 72hw, respectively, and flow into the different high-temperature medium flow paths of the feed water heater FWHP. The water is cooled by the feed water flowing through the low-temperature medium flow path to a temperature that can be treated in the purification units PF3 and PF2, i.e., about 35 to 40°C, and then led to the purification units PF3 and PF2, respectively. Various means including orifices and nozzles can be used as the throttling means 72ow and 72hw depending on the purpose, but in Figure 2, throttling valves with an adjustable degree of throttling are used.

[0038] (Refiner PF2 and PF3, Figure 2) In this embodiment, the purification units PF2 and PF3 each use a combination of a degassing membrane GTM having an oxygen removal function and a continuous electrical ion exchange membrane EDI. in particular, PF2 (95 series): GTM2 + EDI2 PF3 (94 series): GTM3 + EDI3

[0039] The reason why EDI is also added to PF3 is that in the present embodiment, the water electrolysis reaction takes place at the anode, and trace amounts of oxonium ions are thought to remain in the 94-system cooling water that cools the anode. Of course, the specifications of the degassing membrane GTM and the continuous ion-exchange membrane EDI will vary depending on the flow rate, content, etc. of the water. The membrane-separated gas components such as hydrogen gas and oxygen gas are discharged using pressure reducing means VP provided in GTM2 and GTM3 and sent to main burner 80 via flues 30 and 29, respectively, for dissipation and combustion. The electrode system wastewater and concentrated water of EDI2 and EDI3 are treated in the same manner as in the purification unit PF1.

[0040] After that, the circulating water from the 95th system After being introduced into the PF2, trace amounts of hydrogen gas are removed by the GTM2, and then the oxonium ions are converted into water by the continuous electric ion exchange membrane EDI2, and other remaining electrolytes are deionized. The concentrated liquid is then treated by the high-pressure reverse osmosis membrane, and the water is recovered. The water quality is at the level of ultrapure water, and the water is then merged into the reservoir 2a inside the relay means 2. The circulating water of line 94 is the same as line 95, The oxygen gas is introduced into the PF3 and removed by the GTM3, after which the oxonium ions are converted into water by the continuous electric ion exchange membrane EDI3, and other remaining electrolytes are deionized. The concentrated liquid is then treated by the high-pressure reverse osmosis membrane to recover water, and the water quality becomes that of ultrapure water, which then flows into the storage water reservoir 2a inside the relay means 2.

[0041] (Circulation means, Figures 1 to 3, Figures 4 to 6) The reason why the feed water that has joined the relay means is sent from the relay means to the solid polymer water electrolysis device and circulated is the difference between the pressure head of the feed water pump FP1 and the positional head of the water surface depth h of the relay means. This function is provided by the water supply pump FP1 and the throttle valves 72ow and 72hw, and in this sense, these mechanical elements are collectively referred to as the circulation means.

[0042] According to the embodiment of the present application, by selecting an appropriate section on the boiler feedwater pipeline and applying the above-described circulation means, it is possible to remove heat that is inevitably generated during operation of the solid polymer water electrolysis apparatus, and to recover 100% of the removed heat, thereby enabling the heat efficiency to be improved.

[0043] (Feedwater heater FWH3 - Feedwater heater FWH4 - Raw water heater FWH6, Figure 1) The feedwater flow past point 4 is pressurized to a predetermined pressure by feedwater pump FP2 and then passes through feedwater heaters FWH4 and FWH3. The heating source for these two feedwater heaters is the extracted steam from the high-pressure steam turbine Th (extraction point B4, 64 system). where: FWH3 is feedwater-superheated steam (extracted steam), FWH4 is feedwater - boiling water It is a heat exchanger between the

[0044] The saturated water discharged from point B8 of the FWH4, i.e., drain, The drain pressure drops (isenthalpic change) as it passes through the throttle valve 72, and is re-boiled. The re-boiled drain flows into the raw water heater FWH6, where it exchanges heat with the raw water, raising the temperature of the raw water to about 35°C to 40°C, and the drain becomes saturated water. The drain is then depressurized by another throttle valve 72 and flows into the condenser 7. 1 and 2, the motors that drive the water supply pumps FP1 and FP2 are omitted.

[0045] (Feedwater heater FWH2 and feedwater heater FWH1, Figure 1, Figure 3-2) The feedwater leaving the feedwater heater FWH3 enters the feedwater heater FWH2. The heat source for the feedwater heater FWH2 is the exhaust gas of the second-stage gas turbine Tgt2 discharged from the final-stage feedwater heater FWH1, and the pressure of the exhaust gas is reduced by a throttle valve 72f1. The exhaust gas from FWH2 is led to a condenser. The FWH1 also serves as a gas cooler for the gas turbine cycle of the present invention, and is connected to the exhaust outlet of the second stage gas turbine Tgt2 via a pipe line.

[0046] (Steam Generator 1, Figure 1) The working medium (feedwater) reaches the steam generator 1 . The steam generator 1 houses and arranges the boiler B, superheater SH, and reheater RH, and high-temperature gas flowing in from the main burner 80 exchanges heat with each of the heat exchangers to heat the working medium to a predetermined temperature. The present invention can be applied to any type of boiler as the boiler B, but a once-through boiler is preferred because it has high response to load fluctuations in line with the fast response of the solid polymer water electrolysis apparatus and the hydrogen-oxygen combustion gas turbine. The main burner 80 is configured to be capable of not only hydrogen and oxygen combustion but also air and natural gas combustion. The air supply system is a pipe 81.

[0047] (Oxygen gas, hydrogen gas, natural gas storage tanks, Figure 1) Note that Og, Hg, and Ng depicted near the main burner 80 indicate storage tanks for oxygen gas, hydrogen gas, and natural gas, respectively. These storage tanks are identical to the tanks of the same symbols connected to systems 53 and 54, respectively.

[0048] (Steam turbine, Figure 1) The working medium that has been superheated as steam in the superheater SH flows through a pipe 46 and a point B3 into a high-pressure steam turbine Th, where it undergoes adiabatic expansion to generate power (point B4). Near point B4, there is an extraction pipeline 64 heading towards the feedwater heaters FWH3, FWH4, and FWH6. An extraction point of the extraction pipe line 49 leading to the ejector 49a is provided. In the embodiment of FIG. 1, the ejector 49a is shown as a single unit for the sake of simplicity, but typically multiple stages are provided.

[0049] The working medium, whose temperature and pressure have been reduced in the high-pressure steam turbine Th, is isobarically heated in the reheater RH to approximately the inlet temperature of the high-pressure steam turbine Th, flows into the low-pressure steam turbine Tl, is adiabatically expanded to generate a large amount of power, and flows into the condenser 7. The steam turbine plant in question has two stages, and the temperature and pressure conditions are the same as those of standard land- or marine-use steam turbine plants. Of course, a single stage is also possible. It is also possible to upgrade an out-of-service power plant to the power plant of this invention. In the present embodiment, the working medium that has flowed into the condenser 7 releases heat to cooling seawater, and the condensed water is stored as ultrapure water, drinking water, bath water, heated swimming pool water, or detergent-free laundry water, or is transferred to a downstream process such as ammonia synthesis.

[0050] (Pressure-balanced water electrolysis: basic configuration, Figure 3; single-stage gas turbine, Figure 3-1) The present invention employs a method of generating hydrogen gas and oxygen gas in a stoichiometric ratio at a pressure substantially equal to the water supply pressure (e.g., 1 MPa) to the solid polymer water electrolysis device, The gas (steam) compression process in a normal gas turbine cycle is This is replaced by a combination of pressurized boiler feedwater and a solid polymer water electrolysis device, and a gas turbine cycle is constructed without using a gas compressor to generate power.

[0051] In Figure 3-1, The pipes are configured so that the oxygen gas flowing from the oxygen separation vessel 55 into the pipe 53 reaches a mixing chamber 86, where it is premixed with bleed steam 88 from an extraction point A1 on the high-pressure side of the low-pressure steam turbine T1, and then flows into a front chamber 65f of the hydrogen-oxygen combustor 65. Here, the oxygen gas and the bleed steam may be introduced to the hydrogen-oxygen combustor 65 via separate routes without being premixed. The pipeline is configured so that the hydrogen gas flowing from the hydrogen separation vessel 58 into the pipeline 54 reaches the side of the front chamber 65 f of the combustor 65 . The air-fuel mixture and the hydrogen gas are configured to flow into the combustion chamber via separate flow paths in an injector 69 .

[0052] When hydrogen gas and oxygen gas are ignited and burned, a conduit from the gas outlet of the oxygen separation vessel 55 to the injector 69 of the combustor 65; a conduit from the gas outlet of the hydrogen separation vessel 58 to the injector 69 of the combustor 65; A section via the combustor 65 to the nozzle inlet of the gas turbine Tgt1 The gas pressure is The pressure is maintained at, for example, 1 MPa by a pressure balancing means. The pressure balancing means comprises: Oxygen side back pressure control valve 73o and pressure gauge P and Hydrogen side back pressure control valve 73h and pressure gauge P It consists of a back pressure control system. If the pressure in this section exceeds the set value, 1 MPa, the back pressure control valve is instantly activated and the internal gas is released to the main burner and combusted via flue 29 (if back pressure control valve 73o is activated) or flue 30 (if back pressure control valve 73h is activated) until the pressure drops to the set value (Figure 3, Figure 3-1). In this way, the oxygen gas and the hydrogen gas are generated at 1 MPa, Since constant pressure combustion is performed in the combustor 65, The section up to the nozzle of the gas turbine Tgt1 is maintained at 1 MPa. Here, the nozzle also functions as a throttle means for maintaining pressure in the back pressure control system. Patent Document 2 proposes a highly accurate pressure balancing means specialized for solid polymer water electrolysis devices. In Fig. 3-1 relating to the embodiment of the present application, a pressure balancing means using a back pressure control valve with a compact diaphragm valve, which has a proven track record in general industrial use, is used.

[0053] As described above, the gas (steam) discharged from the gas turbine Tgt1 flows into the final-stage feedwater heater FWH1 to heat the boiler feedwater. The exhaust gas is depressurized by the throttle valve 72f1 and flows into the feedwater heater FWH2 to heat the feedwater. The thing to note here is that The magnitude of the heat amount received by the feedwater upstream of the feedwater heater FWH2, or, Depending on the amount of exhaust heat of the gas turbine, In the final stage feedwater heater FWH1, the feedwater serving as the working medium may enter the boiling region. In this state, the "FWH1" functions as both a feedwater heater and a steam generator. The feedwater heater upstream of the feedwater heater FWH2 primarily refers to the "FWHP." In the case of a gas turbine alone, the configuration of the gas turbine + steam generator is publicly known, Even in combined cycle systems consisting of a gas turbine and a steam turbine, the configuration of a steam generator is generally adopted.

[0054] (Pressure-balanced water electrolysis, n-stage gas turbine, Figure 3-2) n is a positive integer. FIG. 3-2 shows an embodiment where n=2. The oxygen gas flowing from the oxygen separation vessel 55 into the pipe 53o1 reaches the mixing chamber 86, The air-fuel mixture is premixed with the extracted air 88 from the extraction point A1 on the high-pressure side of the low-pressure steam turbine Tl to form an air-fuel mixture. The air-fuel mixture flows into the front chamber 65f of the first-stage combustor 65 along a pipe connecting the mixing chamber 86 and the first-stage combustor 65. Here, the oxygen gas and the extracted steam may be introduced into the hydrogen-oxygen combustor via separate routes without being premixed. The exhaust outlet A2 of the first stage combustor 65 is connected to the inlet of the first stage gas turbine Tgt1, The gas outlet A3I of the first stage gas turbine Tgt1 is The oxygen gas is premixed with the oxygen gas flowing in from the pipe 53o2, and then The duct is configured to flow into a front chamber 66 f of the second stage combustor 66 . The hydrogen gas flowing into the pipeline 54 from the hydrogen separation vessel 58 is A duct is configured to reach the side surface of the front chamber 66f of the second stage combustor 66 via the duct 54h2. The air-fuel mixture and the hydrogen gas are configured to flow into the combustion chamber (the internal space of each inner cylinder 68) while following separate flow paths in the injector 69b. As shown in Figure 3-2, a two-stage gas turbine cycle also uses a pressure balancing means similar to that used in a single-stage gas turbine cycle, and the pressures of the water supply to the solid polymer water electrolysis device and the generated oxygen gas and hydrogen gas are at most about 1 MPa.

[0055] In order to cool the inside of the outer casing 67b, the second stage combustor 66 is configured such that superheated steam 89 at a low temperature of about 240°C is injected from steam tubes 71 provided at several locations on the circumference from the low-pressure side extraction point A12 of the low-pressure steam turbine T1, thereby cooling the inside of the outer casing 67b and keeping the outer casing 67b, which is a pressure-resistant container, at a temperature below which creep does not occur. As a result, while suppressing the second stage gas turbine inlet temperature to, for example, 1600°C, This makes it possible to increase the amount of additional hydrogen gas and oxygen gas used for combustion, which increases the weight flow rate of the working fluid flowing through the second-stage gas turbine and feedwater heaters FWH1 and 2, thereby increasing output and thermal efficiency.

[0056] According to the configuration of the present embodiment, As described above, the amounts of dilution steam, combustion hydrogen gas, and oxygen gas can be set independently for both the first and second stage combustors, so the temperature of the high-pressure first stage combustor can be kept low (e.g., 0.8 MPa, 1400°C) and the temperature of the low-pressure second stage combustor can be increased (e.g., 0.2 MPa, 1600°C), facilitating the selection of materials for the pressure vessel. The pressure of the feedwater flowing into the solid polymer water electrolysis device is low, allowing the use of lightweight, highly reliable mass-produced products. Because a pressure-balanced gas generation method is used, compared to the differential pressure type, there is almost no lateral force acting on the cell elements that make up the stack, significantly improving the durability of the cell elements.Since there is no differential pressure between the cathode side (hydrogen gas generation side) and the anode side (oxygen gas generation side), the amount of cross-penetration of hydrogen gas from the cathode side to the anode side is reduced, which is expected to improve safety. If the first and second stage combustors are each constructed of a group of thin-walled, small-diameter combustion tubes arranged in a cannular arrangement, the weight will be reduced and the responsiveness will be improved. From the viewpoint of the power plant, the heat generated by the solid polymer water electrolysis device is not a heat loss but an additional heat source other than the fuel for the main burner. Furthermore, if the present invention is applied to a ship and the gas turbine is used exclusively for propulsion, the gas turbine shaft connected to the propulsion device does not have a compressor, so the moment of inertia of the gas turbine shaft is significantly reduced, making starting and speed changes easier, and improving maneuverability. Significant cost savings can also be expected.

[0057] (Environmental impact on the sea near the power plant) According to the results of calculations using the open system, for a freshwater recovery rate of 50%, the temperature and salinity of the wastewater after the wastewater is combined will increase by approximately 5.4°C and the salinity by only 0.02% compared to the surrounding sea area. [Explanation of symbols]

[0058] 1: Steam generator 2: Relay method 2a: Transfer means storage basin 4: Fuel water and circulating cooling water outlet point 7: Surface condenser 7he: Heat exchanger 7w: Hotwell 9: Water supply raw water system 10: Cooling seawater inlet pipe 11: Cooling seawater outlet piping 12: Water intake 13: Ultrafiltration membrane 13x: Ultrafiltration membrane 14: High-pressure reverse osmosis membrane 27: Waste water collecting pipe 28: Continuously electrically regenerated ion exchange membrane drainage pipe 31: High-pressure reverse osmosis membrane permeated water 40: Low-pressure reverse osmosis membrane 41: Low-pressure reverse osmosis membrane permeated water 43: Water supply pipe 53: Oxygen gas pipeline 53o1: Diluted oxygen gas line 53o2: Diluted oxygen gas pipeline 54: Hydrogen gas pipeline 54h1: Hydrogen gas pipeline 54h2: Hydrogen gas pipeline 55: Oxygen separation container 55a: Oxygen separation vessel storage basin 57: Stack 58: Hydrogen separation vessel 58a: Hydrogen separation vessel storage basin 60: Oxygen gas (bubbles in stored water) 62: Ultrapure water utilization system (post-process) 63: Switching valve for ultrapure water system and drinking water system 73h: Hydrogen side back pressure control valve 73o: Oxygen side back pressure control valve 75: Check valve 80: Main burner 88: Dilution steam line 89: Dilution steam line 90:Fuel water / circulating cooling water intake system 94: Oxygen gas side circulation drainage 95: Hydrogen gas side circulation drainage EDI: Continuously electrically regenerated ion exchange membrane FP1: Water pump FP2: Water pump GTM: Degassing membrane PF1: Purification equipment PF2: Purification equipment PF3: Purification equipment

Claims

1. a water electrolysis device, a solid polymer water electrolysis device including a hydrogen separation vessel and an oxygen separation vessel; A boiler, a feedwater, a feedwater heater, a steam turbine, a condenser, a high-temperature medium flow path and a low-temperature medium flow path through which the feedwater flows, both of which are provided inside the feedwater heater; It consists of the low-temperature medium flow path is in communication with a first purification device provided in a water supply line upstream thereof; The effluent water originating from the hydrogen separation vessel is A pipe is configured to be passed through the high-temperature medium flow path of the feedwater heater, cooled by the feedwater, treated in a second purification device, and directed to the low-temperature medium flow path; The effluent water originating from the oxygen separation vessel is A pipe is configured to pass through another hot medium flow path of the feedwater heater, be cooled by the feedwater, be treated in a third purification device, and direct the cold medium flow path; a power plant provided with a pipeline connecting the low-temperature medium flow path to the solid polymer water electrolysis device;

2. In claim 1, A relay means is provided, the relay means being made of a housing; The relay means has a space at the top and a water supply reservoir at the bottom, A pressure reducing means is provided in the upper space, The water supply reservoir, a low-temperature medium flow path and a first to third purification device; a throttle means is provided between the hydrogen separation vessel and the high-temperature medium flow path; a throttle means is provided between the oxygen separation vessel and the separate high-temperature medium flow path; a power plant, wherein a feedwater pump is disposed in a pipe connected adjacent to the low-temperature medium flow path;

3. In claim 1, a pressure balancing means for controlling a pressure in a hydrogen gas pipeline and a pressure in an oxygen gas pipeline of the solid polymer water electrolysis device so as to balance the pressure therebetween, a hydrogen gas pipeline and an oxygen gas pipeline are provided connecting the solid polymer water electrolysis apparatus and the hydrogen-oxygen combustor; A power plant including a gas turbine, the power plant being provided with an extraction pipe connecting an extraction port provided in the steam turbine and the hydrogen-oxygen combustor.

4. In claim 3, The hydrogen-oxygen combustor is provided in a single stage, and the gas turbine is provided in a single stage, the hydrogen-oxygen combustor is disposed upstream of the gas turbine; A power plant in which the exhaust outlet of said gas turbine is connected to another feedwater heater or steam generator of said steam turbine plant.

5. In claim 3, Both the hydrogen-oxygen combustor and the gas turbine are provided with n stages (n is a number equal to or greater than 2), The hydrogen-oxygen combustors for each stage are located upstream of the gas turbines for each stage. the (n-1)th stage gas turbine is disposed upstream of the nth stage hydrogen-oxygen combustor; A power plant in which the exhaust outlet of an nth stage gas turbine is connected to another feedwater heater or steam generator of said steam turbine plant.

6. In claim 1, The power plant, wherein the first, second and third purification devices are comprised of a degassing membrane and a continuous electrically regenerated ion exchange membrane.

7. In claim 1, The power plant, wherein the first purification device inlet is connected to a hot well provided below the condenser via a transfer pump.

8. In claim 1, The feedwater treated in the first purification device is permeated water that has been desalinated in a reverse osmosis membrane module, A power plant including a system in which raw water is heated to a predetermined temperature by drain discharged from another feedwater heater provided adjacent to the feedwater heater on the downstream side.

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