High-pressure combustion combined heat and power generation energy storage system and method for producing hydrogen and oxygen through electrolysis

Abstract

The invention discloses a high-pressure combustion combined heat and power generation energy storage system and method for hydrogen and oxygen production through electrolysis, and relates to the field of hydrogen energy storage. After the electrolytic cell produces high-pressure hydrogen and oxygen, the high-pressure hydrogen and oxygen are stored in the hydrogen / oxygen storage tank, the system can operate in a hydrogen / oxygen mode, and in the oxygen mode operation, the hydrogen and oxygen steam mixed gas from the oxygen storage tank and the hydrogen / oxygen evaporation compressor are combusted in the high-pressure combustion chamber to generate superheated steam, and then the superheated steam enters the expansion turbine to do work; due to excessive oxygen, dead steam after acting is separated into two working media through a gas-liquid separator, that is, gas enters a cooler to be cooled and then returns to a combustion chamber through a hydrogen / oxygen evaporation compressor, drainage water generated after liquid enters a heat supply heat exchanger is pressurized through a water pump and then enters a high-temperature combustion chamber, and therefore clean utilization of hydrogen energy and cyclic regeneration of the working media are achieved. The system can realize high power generation efficiency and excellent environmental protection performance, and is suitable for regions requiring stable consumption of fluctuating renewable energy sources, power and heat supply and the like.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen energy storage, specifically relating to a combined heat and power energy storage system and method for high-pressure combustion of hydrogen and oxygen produced by electrolysis. Background Technology

[0002] Renewable energy sources such as wind and solar power exhibit significant intermittency, volatility, and regionality. Their large-scale grid connection poses a severe challenge to the stable operation of the power grid, leading to frequent instances of "wind and solar curtailment" and resulting in substantial energy waste. Therefore, developing efficient, large-scale, and long-cycle energy storage and conversion technologies is crucial for achieving a high proportion of renewable energy consumption. Hydrogen energy, as an abundant, green, low-carbon, and widely applicable secondary energy source, is hailed as the "ultimate energy of the 21st century." It can serve as an efficient energy carrier, converting difficult-to-store electrical energy into chemical energy for storage and transportation; it can also be widely used as a clean fuel and feedstock in transportation, industry, and power generation. Against this backdrop, the technological path of converting surplus renewable energy electricity into hydrogen energy (i.e., "green hydrogen") through water electrolysis and then efficiently utilizing it according to end-user demand demonstrates enormous development potential. Combined heat and power (CHP) systems based on alkaline electrolyzers for hydrogen production, combined with hydrogen-oxygen combustion power generation and heating, represent one of the most promising directions within this technological path.

[0003] Alkaline electrolyzers are currently the most mature, commercially viable, and cost-effective water electrolysis technology for hydrogen production. The core principle involves passing a direct current through an electrolyzer filled with a high-concentration alkaline electrolyte (typically a 25%-30% potassium hydroxide solution), causing the water to undergo electrochemical decomposition. The electrolyzer consists of a cathode, an anode, and a membrane that allows hydroxide ions to pass through but effectively prevents hydrogen and oxygen from mixing. At the cathode, water molecules accept electrons, are reduced to hydrogen, and hydroxide ions are released. These hydroxide ions, under the influence of an electric field, migrate through the membrane to the anode. At the anode, the hydroxide ions release electrons and are oxidized to produce oxygen and water. A significant advantage of this technology is the use of non-precious metal catalysts (such as nickel and nickel-molybdenum alloys), which greatly reduces costs, and the system boasts a robust structure and long lifespan. However, its drawbacks include relatively slow start-up and shutdown speeds and power response, and its adaptability to fluctuations in renewable energy power needs improvement.

[0004] Cogeneration, also known as combined cycle cogeneration, is a core energy-saving technology in the energy sector. In conventional separate production models, power plants release large amounts of heat energy into the environment as waste steam, while heating boilers consume fuel separately, resulting in overall energy efficiency generally below 50%. The core of cogeneration lies in breaking this "separate production" model. It uses an integrated system (usually powered by a gas turbine, internal combustion engine, or steam turbine) to first burn fuel to generate electricity, then recovers the high-grade heat energy that would otherwise be wasted for use in industrial processes, district heating, or cooling, thus achieving "cascade utilization" of primary energy. The most significant advantage of this model is its extremely high overall energy efficiency, reaching over 80%, which significantly reduces fuel consumption and carbon emissions, while saving users considerable energy costs and enhancing the reliability of district power supply. Despite its high efficiency, the widespread application of cogeneration still faces a series of inherent drawbacks and serious challenges. First, its superior economic efficiency and effectiveness heavily rely on a stable and matched thermal load. Second, the high initial investment in the system constitutes a significant market entry barrier. Simultaneously, the system's start-up, shutdown, and load regulation response speeds are limited, and maintenance requires specialized expertise. Finally, and most critically, its environmental benefits have a "ceiling": while mainstream natural gas-driven combined heat and power (CHP) is cleaner than coal-fired power, it still fundamentally relies on fossil fuels, continuously generating carbon dioxide emissions, and its long-term competitiveness will face challenges. A Chinese patent application (application number: 202210317616.6) mentions a wind-solar-energy storage system coupled with water electrolysis for hydrogen production and oxygen-enriched combustion power generation. This system effectively recovers abandoned wind and solar power and improves the efficiency of electricity-to-electricity conversion, but it does not solve the problems of high energy consumption and long start-up time for the electrolyzer, the chemical corrosiveness caused by carbon dioxide as the circulating working fluid, and the increased safety risks under oxygen-enriched conditions. Summary of the Invention

[0005] In view of the defects or deficiencies of the prior art, the purpose of this invention is to provide a cogeneration energy storage system and method for producing hydrogen and oxygen by high-pressure combustion through electrolysis. This invention can reduce pollutant emissions and achieve high-efficiency power generation and stable absorption of fluctuating renewable energy sources.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A combined heat and power (CHP) energy storage system for producing hydrogen and oxygen through electrolysis and high-pressure combustion includes an electrolyzer, a high-pressure combustion chamber, an expansion turbine, a gas-liquid separator, a cooler, a heat exchanger, a hydrogen / oxygen vapor compressor, and a water pump. The hydrogen outlet of the electrolyzer is connected to the hydrogen inlet of the high-pressure combustion chamber, the oxygen outlet of the electrolyzer is connected to the oxygen inlet of the high-pressure combustion chamber, the steam outlet of the high-pressure combustion chamber is connected to the steam inlet of the expansion turbine, the exhaust steam outlet of the expansion turbine is connected to the exhaust steam inlet of the gas-liquid separator, the gas phase working fluid outlet of the gas-liquid separator is connected to the gas phase working fluid inlet of the cooler, the gas phase working fluid outlet of the cooler is connected to the gas phase working fluid inlet of the high-pressure combustion chamber via the hydrogen / oxygen vapor compressor, and the liquid phase working fluid outlet of the gas-liquid separator is connected to the liquid phase working fluid inlet of the heat exchanger. The outlet of the heat exchanger is divided into two paths: one for drainage and the other for connection to the water inlet of the high-pressure combustion chamber via the water pump.

[0007] A further improvement of the present invention is that it also includes a hydrogen storage tank and an oxygen storage tank, wherein the hydrogen outlet of the electrolyzer is connected to the hydrogen inlet of the high-pressure combustion chamber via the hydrogen storage tank, and the oxygen outlet of the electrolyzer is connected to the oxygen inlet of the high-pressure combustion chamber via the oxygen storage tank.

[0008] A further improvement of the present invention is that the wastewater generated by the cooler and the heat exchanger is transported to the electrolytic cell.

[0009] A further improvement of this invention is that the hydrogen / oxygen vapor compressor and the expansion turbine adopt a split-shaft decoupled design structure. The hydrogen / oxygen vapor compressor is driven by a motor equipped with variable frequency speed regulation, which enables the flow rate and pressure ratio of the hydrogen / oxygen vapor compressor to be actively adjusted independently of the expansion turbine operating conditions.

[0010] A further improvement of the present invention is that it also includes a cooling tower connected to a heat exchanger.

[0011] A further improvement of the present invention is that two sets of regenerative devices are added at the exhaust steam outlet of the expansion turbine, namely, an oxygen heater and a water heater are respectively installed on the exhaust or extraction steam pipeline of the expansion turbine to form an independent regenerative circulation loop. The oxygen heater uses the heat energy of steam to raise the water temperature; the water heater raises the feedwater temperature by recovering the waste heat of steam.

[0012] A further improvement of the present invention is that a hot water storage tank is added at the outlet of the heat exchanger to form a heat energy buffer and distribution center; at the same time, a portion of the heat energy can be diverted from the heating network at the tail of the heat exchanger to heat the inlet water of the electrolytic cell.

[0013] A further improvement of the present invention is that a lithium bromide refrigeration device is added to the downstream section of the electrolyzer to construct a closed waste heat utilization loop. The superheated heat generated by the electrolyzer is introduced to the generator of the lithium bromide refrigeration device as a driving energy to produce chilled water. The chilled water produced is then reused in the cooling system of the electrolyzer to force-cool it.

[0014] A method for cogeneration and energy storage of hydrogen and oxygen produced by electrolysis under high pressure combustion, the method being based on the aforementioned cogeneration and energy storage system for hydrogen and oxygen produced by electrolysis under high pressure combustion, comprising: After producing high-pressure hydrogen and oxygen in an alkaline electrolyzer, under oxygen mode operation, the hydrogen and oxygen, along with the oxygen vapor mixture from the hydrogen / oxygen vapor compressor, undergo high-temperature and high-pressure combustion in the high-pressure combustion chamber. This mixture is then mixed with water from the water pump to generate superheated steam, which subsequently enters the expansion turbine to perform work and output mechanical energy. In the case of excess oxygen, the exhaust steam after performing work is separated into two working fluids by a gas-liquid separator. The gaseous working fluid enters the cooler for cooling and then returns to the high-pressure combustion chamber via the hydrogen / oxygen vapor compressor. The liquid working fluid enters the heat exchanger for heat exchange, and a portion of the resulting wastewater is then pressurized by the water pump and enters the high-pressure combustion chamber. By varying the water pump flow rate, the temperature of the high-pressure combustion chamber is controlled, achieving clean utilization of hydrogen energy and recycling of the working fluid.

[0015] A further improvement of the present invention is that it also includes: in hydrogen mode operation, the working characteristic is hydrogen-rich combustion, in which oxygen and hydrogen, as well as hydrogen vapor mixture from hydrogen vapor compressor, are subjected to high-temperature and high-pressure combustion in high-pressure combustion chamber and mixed with working fluid water from water pump to generate superheated steam, which then enters expansion turbine to do work and output mechanical energy. Due to the excess hydrogen, the exhaust steam after doing work is separated into two working fluids after passing through gas-liquid separator, namely, the gas phase working fluid enters the cooler to cool down and then returns to the high-pressure combustion chamber through hydrogen vapor compressor, and the liquid phase working fluid produced by separation enters the heat exchanger for heat exchange. A portion of the drainage generated after heat exchange is then pressurized by water pump and enters the high-pressure combustion chamber.

[0016] Compared with the prior art, the present invention has at least the following beneficial technical effects: This invention provides a combined heat and power (CHP) energy storage system and method for electrolytic hydrogen and oxygen production and high-pressure combustion. Water is used as the core working fluid, and hydrogen and oxygen cycles are performed simultaneously to achieve energy storage (electrolysis) and energy release (combustion work). Hydrogen and oxygen serve as the "chemical energy carrier" and reactants in the cycle: the hydrogen cycle is the circulation of fuel and energy carriers in the system. First, water passes through an alkaline electrolyzer to produce high-purity hydrogen, converting electrical energy into the chemical energy of the hydrogen, thus storing energy. Then, it enters a high-pressure combustion chamber and undergoes vigorous combustion with the oxygen flow, converting the chemical energy into the thermodynamic energy of high-temperature, high-pressure water vapor, thus releasing energy. When the system operates in hydrogen mode, the flow rate of hydrogen entering the high-pressure combustion chamber exceeds the required stoichiometric ratio. Finally, a portion of the hydrogen and high-temperature, high-pressure water vapor enters an expansion turbine to perform work and output mechanical energy. The exhaust steam, after being processed by a gas-liquid separator, is then pressurized by a hydrogen vapor compressor and returned to the high-pressure combustion chamber as return gas. The oxygen cycle is the circulation of the oxidant and working fluid in the system. First, water is converted into oxygen in the electrolytic cell. When the system is running in oxygen mode, the oxygen flow rate entering the high-pressure combustion chamber is much greater than the required stoichiometric ratio. Some oxygen and hydrogen are violently burned in the high-pressure combustion chamber to produce high-temperature and high-pressure steam. Then, it enters the expansion turbine to do work and output mechanical energy. Finally, the oxygen and steam mixture passes through the gas-liquid separator and is then pressurized by the oxygen-vapor compressor and returned to the high-pressure combustion chamber.

[0017] Furthermore, the hydrogen / oxygen vapor compressor and the expansion turbine adopt a split-shaft decoupled design structure. The hydrogen / oxygen vapor compressor is driven by a motor equipped with variable frequency speed control, which allows the flow rate and pressure ratio of the hydrogen / oxygen vapor compressor to be actively adjusted independently of the expansion turbine operating conditions, thus optimizing the system's operating performance under different loads.

[0018] Furthermore, to address the operational needs during the high temperatures of summer and the non-heating season, a cooling tower is added after the heating heat exchanger to efficiently remove waste heat from the system, maintain the working fluid parameters within permissible ranges, and ensure operational reliability and economy under safe operating conditions.

[0019] Furthermore, two sets of regenerative devices are added at the exhaust steam outlet of the expansion turbine. Specifically, an oxygen heater and a water heater are respectively installed on the exhaust or extraction steam pipeline of the expansion turbine, forming an independent regenerative circulation loop. The oxygen heater uses steam heat energy to raise the water temperature; the water heater raises the feedwater temperature by recovering steam waste heat, reducing irreversible losses during the system heat exchange process, thereby improving the overall thermal efficiency of the system and realizing energy cascade utilization.

[0020] Furthermore, before injection, all fluid working fluids entering the high-pressure combustion chamber can first flow through one or more regenerators to exchange heat with the high-temperature exhaust steam from the expansion turbine before reacting in the high-pressure combustion chamber. This effectively recovers the waste heat from the exhaust steam, increases the initial temperature of the working fluid entering the high-pressure combustion chamber, and improves efficiency.

[0021] Furthermore, a hot water storage tank is added at the outlet of the heat exchanger to create a heat energy buffer and distribution center. At the same time, a portion of the heat energy can be diverted from the heating network at the tail of the heat exchanger to heat the inlet water of the electrolytic cell. The optimal operating temperature of the electrolytic cell needs to be maintained at around 80°C. If the inlet water temperature is too low, the start-up will consume a lot of energy and time. Introducing a stable external heat source to preheat the inlet water can keep the electrolytic cell in a "hot standby" state for a long time, greatly improving the operational flexibility and response speed.

[0022] Furthermore, to address the challenges of heat dissipation and overheating risks in summer, a lithium bromide refrigeration unit is added to the downstream section of the electrolyzer, creating a closed-loop waste heat utilization loop. The overheated heat generated by the electrolyzer is directed to the generator of the lithium bromide refrigeration unit, which serves as the driving energy for producing chilled water. The chilled water is then reused in the electrolyzer's cooling system for forced cooling, thereby achieving precise control over the electrolyzer's operating temperature and maintaining it within the ideal operating range of around 80°C, preventing the vaporization of water within the electrolyzer.

[0023] In summary, this invention can reduce pollutant emissions and achieve high-efficiency power generation and stable absorption of fluctuating renewable energy sources. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a combined heat and power energy storage system for high-pressure combustion of hydrogen and oxygen produced by electrolysis according to the present invention.

[0026] The labels in the diagram represent: 1. Electrolyzer, 2. Hydrogen storage tank, 3. Oxygen storage tank, 4. High-pressure combustion chamber, 5. Expansion turbine, 6. Gas-liquid separator, 7. Cooler, 8. Heat exchanger, 9. Hydrogen / oxygen vapor compressor, 10. Water pump. Detailed Implementation

[0027] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0033] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0034] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0035] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0036] Example 1 like Figure 1 As shown, the present invention provides a combined heat and power (CHP) energy storage system for producing hydrogen and oxygen through electrolysis and high-pressure combustion, comprising an electrolytic cell 1, a high-pressure combustion chamber 4, an expansion turbine 5, a gas-liquid separator 6, a cooler 7, a heat exchanger 8, a hydrogen / oxygen vapor compressor 9, and a water pump 10. The hydrogen outlet of the electrolytic cell 1 is connected to the hydrogen inlet of the high-pressure combustion chamber 4, the oxygen outlet of the electrolytic cell 1 is connected to the oxygen inlet of the high-pressure combustion chamber 4, the steam outlet of the high-pressure combustion chamber 4 is connected to the steam inlet of the expansion turbine 5, the exhaust steam outlet of the expansion turbine 5 is connected to the exhaust steam inlet of the gas-liquid separator 6, the gas phase working fluid outlet of the gas-liquid separator 6 is connected to the gas phase working fluid inlet of the cooler 7, the gas phase working fluid outlet of the cooler 7 is connected to the gas phase working fluid inlet of the high-pressure combustion chamber 4 via the hydrogen / oxygen vapor compressor 9, and the liquid phase working fluid outlet of the gas-liquid separator 6 is connected to the liquid phase working fluid inlet of the heat exchanger 8. The outlet of the heat exchanger 8 is divided into two paths: one for drainage and the other connected to the water inlet of the high-pressure combustion chamber 4 via the water pump 10.

[0037] In this embodiment, a hydrogen storage tank 2 and an oxygen storage tank 3 are also included. The hydrogen outlet of the electrolyzer 1 is connected to the hydrogen inlet of the high-pressure combustion chamber 4 via the hydrogen storage tank 2, and the oxygen outlet of the electrolyzer 1 is connected to the oxygen inlet of the high-pressure combustion chamber 4 via the oxygen storage tank 3.

[0038] In this embodiment, the drainage generated by the cooler 7 and the heat exchanger 8 is transported to the electrolytic cell 1.

[0039] In this embodiment, the hydrogen / oxygen vapor compressor 9 and the expansion turbine 5 adopt a split-shaft decoupled design structure. The hydrogen / oxygen vapor compressor 9 is driven by a motor equipped with variable frequency speed regulation, which allows the flow rate and pressure ratio of the hydrogen / oxygen vapor compressor 9 to be actively adjusted independently of the operating conditions of the expansion turbine 5, thereby optimizing the system's operating performance under different loads.

[0040] In this embodiment, in order to meet the needs of high temperatures in summer and operation during non-heating periods, a cooling tower is added after the heating heat exchanger 8 to efficiently remove the waste heat of the system, maintain the working fluid parameters within the permissible range, and ensure the reliability and economy of operation under safe conditions.

[0041] In this embodiment, the steam that has already done some work in the intermediate stage extraction section of the expansion turbine 5 is led to the heat exchanger 8 to meet the heating needs of different temperature levels.

[0042] In this embodiment, two sets of regenerative devices are added at the exhaust steam outlet of the expansion turbine 5. Specifically, an oxygen heater and a water heater are respectively installed on the exhaust or extraction steam pipeline of the expansion turbine 5 to form an independent regenerative circulation loop. The oxygen heater uses steam heat energy to raise the water temperature; the water heater raises the feedwater temperature by recovering steam waste heat, reducing irreversible losses during the system heat exchange process, thereby improving the overall thermal efficiency of the system and realizing energy cascade utilization.

[0043] In this embodiment, all fluid working media (such as fuel gas, oxidant, etc.) entering the high-pressure combustion chamber 4 can first flow through one or more regenerators before injection, exchange heat with the high-temperature exhaust gas of the expansion turbine 5, and then react in the high-pressure combustion chamber 4 to effectively recover the waste heat of the exhaust gas and increase the initial temperature of the working media entering the high-pressure combustion chamber 4, thereby improving efficiency.

[0044] In this embodiment, a hot water storage tank is also added at the outlet of the heat exchanger 8 to form a heat energy buffer and distribution center. At the same time, a portion of the heat energy can be diverted from the heating network at the tail of the heat exchanger 8 to heat the inlet water of the electrolytic cell 1. The optimal operating temperature of the electrolytic cell 1 needs to be maintained at around 80°C. If the inlet water temperature is too low, the start-up will consume a lot of energy and time. Introducing a stable external heat source to preheat the inlet water can keep the electrolytic cell 1 in a "hot standby" state for a long time, which greatly improves the operational flexibility and response speed.

[0045] In this embodiment, after the water pump 10 pressurizes the drainage, it can also be connected to the boiler waste heat recovery section. The waste heat of the boiler vaporizes the drainage into water vapor, and then the water vapor is sent back to the high-pressure combustion chamber 4 under the pressure difference. This effectively controls the temperature of the high-pressure combustion chamber 4 and achieves the ultimate goal of energy cascade utilization and energy saving.

[0046] In this embodiment, to address the challenges of heat dissipation and overheating risks in summer, a lithium bromide refrigeration device is added to the downstream section of electrolyzer 1, constructing a closed waste heat utilization loop. The overheated heat generated by electrolyzer 1 is directed to the generator of the lithium bromide refrigeration device, which serves as the driving energy to produce chilled water. The generated chilled water is then reused in the cooling system of electrolyzer 1 to forcibly cool it, thereby achieving precise control over the operating temperature of electrolyzer 1 and maintaining it within the ideal operating range of around 80°C, preventing the vaporization of water inside electrolyzer 1.

[0047] In this embodiment, the process wastewater generated by the system is collected, and impurities and ions are removed by the purification treatment unit so that the water quality meets the electrolysis feed water standard. Then, it is returned to the electrolysis cell 1 as makeup water for recycling.

[0048] Example 2 like Figure 1 As shown, the present invention provides a cogeneration energy storage method for producing hydrogen and oxygen by electrolysis under high pressure and combustion. This method is based on the aforementioned cogeneration energy storage system for producing hydrogen and oxygen by electrolysis under high pressure and combustion, and includes: After high-pressure hydrogen and oxygen are produced by alkaline electrolysis cell 1, under oxygen mode operation, the hydrogen and oxygen, as well as the oxygen vapor mixture from hydrogen / oxygen vapor compressor 9, undergo high-temperature and high-pressure combustion in high-pressure combustion chamber 4 and mix with working fluid water from water pump 10 to generate superheated steam. The superheated steam then enters expansion turbine 5 to do work and output mechanical energy. In the case of excess oxygen, the exhaust steam after doing work is separated into two working fluids by gas-liquid separator 6. The gas phase working fluid (mixture of oxygen and steam) enters cooler 7 for cooling and then returns to high-pressure combustion chamber 4 via oxygen vapor compressor 9. The liquid phase working fluid enters heat exchanger 8 for heat exchange, and part of the resulting drainage is then pressurized by water pump 10 and enters high-pressure combustion chamber 4. By changing the flow rate of water pump 10, the temperature of high-pressure combustion chamber 4 is controlled, realizing the clean utilization of hydrogen energy and the recycling of working fluid.

[0049] In this embodiment, the operation is further characterized by hydrogen-rich combustion under hydrogen mode. Oxygen and hydrogen, as well as a mixture of hydrogen vapor from the hydrogen vapor compressor, are subjected to high-temperature and high-pressure combustion in the high-pressure combustion chamber 4 and mixed with water from the water pump 10 to generate superheated steam. The steam then enters the expansion turbine 5 to perform work and output mechanical energy. Due to the excess hydrogen, the exhaust steam after performing work is separated into two working fluids by the gas-liquid separator 6. The gas phase working fluid (a mixture of hydrogen and steam) enters the cooler 7 to cool down and then returns to the high-pressure combustion chamber 4 via the hydrogen vapor compressor. The liquid phase working fluid produced by the separation enters the heat exchanger 8 for heat exchange. A portion of the wastewater produced after heat exchange is then pressurized by the water pump 10 and enters the high-pressure combustion chamber 4.

[0050] Example 3 like Figure 1As shown, the present invention provides a cogeneration energy storage system for hydrogen and oxygen produced by electrolysis and high-pressure combustion. High-pressure hydrogen and oxygen are produced in an alkaline electrolyzer 1 and stored in hydrogen storage tank 2 and oxygen storage tank 3, respectively. Under oxygen mode operation, the hydrogen, oxygen from oxygen storage tank 3, and oxygen vapor mixture from hydrogen / oxygen vapor compressor 9 undergo high-temperature and high-pressure combustion in high-pressure combustion chamber 4, and mix with working fluid water from water pump 10 to generate superheated steam. This superheated steam then enters expansion turbine 5 to perform work. The high-temperature and high-pressure superheated steam undergoes adiabatic expansion within expansion turbine 5, converting its contained thermal energy into the mechanical energy of the rotor. The torque is then transmitted to a synchronous generator via a rigid coupling, and finally, the generator converts the mechanical energy into electricity. Yes, under conditions of excess oxygen, the exhaust steam after work is separated into two working fluids by the gas-liquid separator 6: a gaseous working fluid (a mixture of oxygen and steam) enters the cooler 7 for appropriate cooling and then returns to the high-pressure combustion chamber 4 via the hydrogen / oxygen vapor compressor 9; and a liquid working fluid enters the heat exchanger 8, where a portion of the resulting wastewater is then pressurized by the water pump 10 and enters the high-pressure combustion chamber 4. The temperature of the high-pressure combustion chamber 4 is controlled by varying the flow rate of the water pump 10. In addition, the water pump 10 can also connect to the boiler waste heat recovery section after pressurizing the wastewater, using the boiler waste heat to vaporize the wastewater into steam, which is then returned to the high-pressure combustion chamber 4 under pressure differential. This effectively controls the temperature of the high-pressure combustion chamber 4 and achieves cascaded energy utilization. This is the method of cogeneration and energy storage for producing hydrogen and oxygen through electrolysis and high-pressure combustion. This method can also be used for hydrogen-mode operation.

[0051] This invention uses water as the core working fluid, simultaneously incorporating hydrogen and oxygen cycles to achieve energy storage (electrolysis) and energy release (combustion). Hydrogen and oxygen serve as the "chemical energy carrier" and reactants in the cycle: the hydrogen cycle is a circulation of fuel and energy carriers. First, water passes through an alkaline electrolyzer 1 to produce high-purity hydrogen, which is then stored in a hydrogen storage tank 2, converting electrical energy into the chemical energy of the hydrogen, thus storing energy. Subsequently, it enters a high-pressure combustion chamber 4 and undergoes vigorous combustion with the oxygen flow, converting the chemical energy into the thermodynamic energy of high-temperature, high-pressure water vapor, thus releasing energy. When the system operates in hydrogen mode, the hydrogen flow rate entering the high-pressure combustion chamber 4 exceeds the required stoichiometric ratio. Finally, a portion of the hydrogen and high-temperature, high-pressure water vapor enters an expansion turbine 5 to perform work and output mechanical energy. The exhaust gas, after being processed by a gas-liquid separator 6, is then pressurized by a hydrogen vapor compressor and returned to the high-pressure combustion chamber 4 as return gas. The oxygen cycle is the circulation of the oxidant and working fluid in the system. First, water is converted into oxygen by electrolysis cell 1 and stored in oxygen storage tank 3. When the system is running in oxygen mode, the oxygen flow rate entering high-pressure combustion chamber 4 is much greater than the required stoichiometric ratio. Some oxygen and hydrogen are violently burned in high-pressure combustion chamber 4 to produce high-temperature and high-pressure water vapor, which then enters expansion turbine 5 to do work and output mechanical energy. Finally, the oxygen and steam mixture passes through gas-liquid separator 6 and is then pressurized by oxygen vapor compressor 9 before returning to high-pressure combustion chamber 4.

[0052] Hydrogen mode operation allows for relatively low combustion temperatures, helping to protect the high-pressure combustion chamber 4 and turbine blades; oxygen mode operation ensures complete fuel combustion and improves combustion efficiency. Subsequently, the return gas path formed by the gas-liquid separator 6 and the hydrogen / oxygen compressor, and the return water path formed by the heat exchanger 8 and the water pump 10, also achieve efficient recovery of unreacted working fluid and effective temperature control of the high-pressure combustion chamber 4. This not only significantly improves economic efficiency but also makes the special combustion organization mode of hydrogen-rich / oxygen-rich combustion feasible and controllable in a closed system. The entire system ultimately achieves near-zero consumption of the working fluid (water), requiring only a small amount to compensate for leaks and wastewater discharge, making it a highly promising future energy solution.

[0053] A cooling tower can be added after the heat exchanger 8 to efficiently remove waste heat from the system and maintain the working fluid parameters within the permissible range; a hot water storage tank can also be added to build a heat energy buffer and distribution center; a portion of the heat energy can also be diverted to heat the inlet water of the electrolytic cell 1, thereby introducing a stable external heat source to preheat the inlet water, so that the electrolytic cell 1 is in a "hot standby" state for a long time, thus solving the problem of the relatively slow start-up and shutdown and power response speed of the electrolytic cell 1.

[0054] An oxygen heater and a water heater can be respectively installed on the exhaust or extraction steam line of the expansion turbine to form an independent regenerative circulation loop. The oxygen heater uses steam heat energy to raise the water temperature and improve the subsequent combustion process; the water heater increases the feedwater temperature by recovering steam waste heat, reducing irreversible losses in the system heat exchange process, thereby improving the overall thermal efficiency of the system and realizing energy cascade utilization.

[0055] Hydrogen, as a carbon-free elemental fuel, produces only water vapor as its sole natural byproduct upon complete combustion, fundamentally eliminating the formation of carbon dioxide, carbon monoxide, and unburned hydrocarbons, thus achieving zero carbon dioxide emissions. Furthermore, hydrogen's wide flammability limit and extremely high flame propagation speed promote rapid and thorough mixing and vigorous reaction with oxygen. This effectively avoids incomplete combustion products caused by partial flameout or uneven mixing during well-organized combustion. Simultaneously, because hydrogen molecules do not contain carbon-carbon or carbon-hydrogen bonds, its combustion process does not undergo the complex cracking and intermediate reactions of fossil fuels, thereby fundamentally preventing the formation of soot and particulate matter. Therefore, it solves the problem that traditional combined heat and power (CHP) cannot achieve zero carbon emissions.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A combined heat and power (CHP) energy storage system for electrolytic hydrogen and oxygen production and high-pressure combustion, characterized in that, It includes an electrolytic cell (1), a high-pressure combustion chamber (4), an expansion turbine (5), a gas-liquid separator (6), a cooler (7), a heat exchanger (8), a hydrogen / oxygen vapor compressor (9), and a water pump (10). The hydrogen outlet of the electrolyzer (1) is connected to the hydrogen inlet of the high-pressure combustion chamber (4), the oxygen outlet of the electrolyzer (1) is connected to the oxygen inlet of the high-pressure combustion chamber (4), the steam outlet of the high-pressure combustion chamber (4) is connected to the steam inlet of the expansion turbine (5), the exhaust steam outlet of the expansion turbine (5) is connected to the exhaust steam inlet of the gas-liquid separator (6), the gas phase working fluid outlet of the gas-liquid separator (6) is connected to the gas phase working fluid inlet of the cooler (7), the gas phase working fluid outlet of the cooler (7) is connected to the gas phase working fluid inlet of the high-pressure combustion chamber (4) via the hydrogen / oxygen steam compressor (9), the liquid phase working fluid outlet of the gas-liquid separator (6) is connected to the liquid phase working fluid inlet of the heat exchanger (8), the outlet of the heat exchanger (8) is divided into two paths, one path is used for drainage, and the other path is connected to the water inlet of the high-pressure combustion chamber (4) via the water pump (10).

2. The cogeneration and energy storage system for electrolytic hydrogen and oxygen production under high pressure combustion according to claim 1, characterized in that, It also includes a hydrogen storage tank (2) and an oxygen storage tank (3). The hydrogen outlet of the electrolyzer (1) is connected to the hydrogen inlet of the high-pressure combustion chamber (4) via the hydrogen storage tank (2), and the oxygen outlet of the electrolyzer (1) is connected to the oxygen inlet of the high-pressure combustion chamber (4) via the oxygen storage tank (3).

3. The cogeneration and energy storage system for electrolytic hydrogen and oxygen production under high pressure combustion according to claim 1, characterized in that, The wastewater generated by the cooler (7) and the heat exchanger (8) is transported to the electrolytic cell (1).

4. A combined heat and power energy storage system for high-pressure combustion of electrolytic hydrogen and oxygen production according to claim 1, characterized in that, The hydrogen / oxygen vapor compressor (9) and the expansion turbine (5) adopt a split-shaft decoupled design structure. The hydrogen / oxygen vapor compressor (9) is driven by a motor equipped with variable frequency speed regulation, which enables the flow rate and pressure ratio of the hydrogen / oxygen vapor compressor (9) to be actively adjusted independently of the operating conditions of the expansion turbine (5).

5. A cogeneration and energy storage system for electrolytic hydrogen and oxygen production under high-pressure combustion according to claim 1, characterized in that, It also includes a cooling tower, which is connected to the heating heat exchanger (8).

6. A cogeneration and energy storage system for electrolytic hydrogen and oxygen production under high pressure combustion according to claim 1, characterized in that, Two sets of regenerative devices are added at the exhaust steam outlet of the expansion turbine (5). Specifically, an oxygen heater and a water heater are respectively installed on the exhaust or extraction steam pipeline of the expansion turbine (5) to form an independent regenerative circulation loop. The oxygen heater uses steam heat energy to raise the water temperature; the water heater raises the feedwater temperature by recovering the waste heat of steam.

7. A cogeneration and energy storage system for electrolytic hydrogen and oxygen production under high-pressure combustion according to claim 1, characterized in that, A hot water storage tank is also added at the outlet of the heat exchanger (8) to form a heat energy buffer and distribution center; at the same time, a portion of the heat energy can be diverted from the heat network at the tail of the heat exchanger (8) to heat the inlet water of the electrolytic cell (1).

8. A cogeneration and energy storage system for electrolytic hydrogen and oxygen production under high pressure combustion according to claim 1, characterized in that, A lithium bromide refrigeration device is added to the subsequent section of the electrolyzer (1) to construct a closed waste heat utilization loop. The superheated heat generated by the electrolyzer (1) is introduced to the generator of the lithium bromide refrigeration device as the driving energy to produce chilled water. The generated chilled water is then reused in the cooling system of the electrolyzer (1) to force it to cool down.

9. A method for cogeneration and energy storage of hydrogen and oxygen produced by electrolysis and high-pressure combustion, characterized in that, This method is based on a cogeneration energy storage system for producing hydrogen and oxygen by electrolysis and high-pressure combustion according to any one of claims 1 to 8, comprising: After producing high-pressure hydrogen and oxygen through an alkaline electrolyzer (1), under oxygen mode operation, the hydrogen and oxygen, as well as the oxygen vapor mixture from the hydrogen / oxygen vapor compressor (9), are subjected to high-temperature and high-pressure combustion in the high-pressure combustion chamber (4) and mixed with working fluid water from the water pump (10) to generate superheated steam. Then, it enters the expansion turbine (5) to do work and output mechanical energy. In the case of excess oxygen, the exhaust steam after doing work is separated into two working fluids after passing through the gas-liquid separator (6). The gas phase working fluid enters the cooler (7) to cool down and then returns to the high-pressure combustion chamber (4) through the hydrogen / oxygen vapor compressor (9). The liquid phase working fluid enters the heat exchanger (8) for heat exchange. A portion of the drainage generated after heat exchange is then pressurized by the water pump (10) and enters the high-pressure combustion chamber (4). By changing the flow rate of the water pump (10), the temperature of the high-pressure combustion chamber (4) is regulated, realizing the clean utilization of hydrogen energy and the recycling of the working fluid.

10. A method for cogeneration and energy storage of hydrogen and oxygen produced by electrolysis under high pressure combustion according to claim 9, characterized in that, Also includes: In hydrogen mode, the working characteristic is hydrogen-rich combustion. Oxygen and hydrogen, as well as hydrogen vapor from the hydrogen vapor compressor, are mixed in the high-pressure combustion chamber (4) at high temperature and high pressure and mixed with water from the water pump (10) to generate superheated steam. Then, it enters the expansion turbine (5) to do work and output mechanical energy. Due to the excess hydrogen, the exhaust steam after doing work is separated into two working fluids after passing through the gas-liquid separator (6). The gas phase working fluid enters the cooler (7) to cool down and then returns to the high-pressure combustion chamber (4) through the hydrogen vapor compressor. The liquid phase working fluid produced by the separation enters the heat exchanger (8). After heat exchange, part of the drainage generated is then pressurized by the water pump (10) and enters the high-pressure combustion chamber (4).

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