Cyclic power generation system integrating green hydrogen-methanol preparation and operation method thereof

Abstract

The invention provides a cyclic power generation system integrating green hydrogen-methanol preparation and an operation method of the cyclic power generation system. The system comprises a cyclic power generation unit, a working medium treatment unit, an electrolytic hydrogen production unit, an oxygen supply pipeline and a methanol preparation and storage unit. According to the system, oxygen is self-produced through electrolyzed water, a high-energy-consumption air separation device is replaced, meanwhile, carbon dioxide separated from power generation waste gas and self-produced hydrogen are synthesized into green methanol, and carbon circulation and chemical energy storage are achieved; methanol can be reused as fuel, and the flexibility of the system is improved by matching with a multi-fuel combustion chamber; turbine exhaust waste heat is recycled in a stepped mode to be used for preheating oxygen and water, a humidifier is introduced to humidify the oxygen so as to adjust the combustion temperature of a combustion chamber, and efficient adjustment of gas turbine output and overall heat efficiency optimization are achieved. And finally, a near-zero-carbon poly-generation energy system of a substance and energy closed loop is constructed.

Description

Technical Field

[0001] This invention belongs to the field of energy system integration technology, and in particular relates to an integrated green hydrogen-methanol production cycle power generation system and its operation method. Background Technology

[0002] In recent years, energy technologies combining renewable energy power generation and carbon dioxide capture and utilization have received widespread attention in order to address climate change and achieve sustainable development. Photovoltaic hydrogen production utilizes photovoltaic power generation, transmitting the generated electricity to an electrolyzer to produce hydrogen and oxygen through water electrolysis. This technology consumes only solar energy and water throughout the entire production process and produces no greenhouse gases. However, methanol is one of the world's most produced chemical raw materials. It is a liquid at room temperature and pressure, making it easy to store and transport as a liquid fuel. It can be produced by photovoltaic hydrogen production, followed by a reaction with captured CO2 in a synthesis reactor to generate methanol, thus achieving electrolytic fuel production. Green methanol production uses renewable energy sources such as photovoltaics and wind power. First, green hydrogen is produced through water electrolysis. Then, CO2 from industrial waste gas or the atmosphere is captured. Under suitable conditions of catalyst, temperature, and pressure, the green hydrogen undergoes a catalytic hydrogenation reaction with CO2, ultimately synthesizing green methanol. This achieves carbon cycling, resulting in a low-carbon or zero-carbon process. Compared to traditional methanol production, this reduces energy costs, alleviates environmental compliance pressures, and lowers the cost of liquid storage and transportation at room temperature and pressure.

[0003] Gas turbine power generation systems based on pure oxygen or oxygen-enriched combustion (such as the Allam cycle) use oxygen as the primary working fluid. Fuels (such as natural gas or syngas) are burned with high-pressure pure oxygen in the combustion chamber, and the resulting high-temperature, high-pressure flue gas drives the turbine to generate electricity. A typical example is the Allam cycle, which uses supercritical CO2 as the working fluid and temperature control medium. Its core features include: recovering and reinjecting a portion of the high-pressure CO2 separated downstream into the combustion chamber to control the turbine inlet temperature; after the working fluid has performed work, it is reheated and cooled, and the water vapor is condensed and separated, resulting in a high-purity CO2 stream that can be stored or utilized. This system boasts high efficiency and a high CO2 capture rate.

[0004] However, pure oxygen combustion systems, exemplified by the Allam cycle, heavily rely on large-scale air separation units to produce high-purity oxygen. The energy consumption of these air separation units is extremely high, typically consuming 15%-20% of the entire power plant's output, significantly reducing the system's overall net efficiency and energy utilization efficiency. Furthermore, high-temperature waste heat and high-quality resources are not efficiently utilized in a cascade manner, and the overall energy utilization efficiency needs improvement. During CO2 separation, the Allam cycle directly discharges high-temperature condensate, which contains a large amount of medium- and low-temperature thermal energy that is not effectively recovered and utilized in existing systems. Simultaneously, the high-purity CO2 generated by the system is usually only considered for storage, without sufficient consideration for its high-value conversion as a feedstock to achieve carbon recycling. In addition, the cascade utilization scheme for gas turbine exhaust waste heat is still imperfect, resulting in room for improvement in the overall thermal efficiency of the system.

[0005] Furthermore, renewable energy sources such as photovoltaic and wind power are intermittent and fluctuating, leading to curtailment of wind and solar power in the existing power system. Traditional gas turbine power generation systems or chemical synthesis systems (such as methanol synthesis) require a stable and continuous energy supply, making it difficult to directly and flexibly adapt to the output fluctuations of renewable energy sources, resulting in the underutilization of clean energy. Moreover, existing gas turbine systems, especially complex cycle systems, have relatively limited adjustment methods under partial load, with limited response speed and adjustment accuracy, and their fuel adaptability needs to be broadened. There is also a lack of deep organic integration and synergistic optimization between various subsystems.

[0006] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide an integrated green hydrogen-methanol production cycle power generation system and its operation method, which solves the problems of low energy utilization, inflexible operation, and poor overall system efficiency and economy caused by the high energy consumption of air separation unit and the difficulty in directly absorbing renewable energy in the independent operation of existing systems such as photovoltaic hydrogen production, green methanol synthesis and Allam cycle.

[0008] To achieve the above and other related objectives, the present invention provides an integrated green hydrogen-methanol production cycle power generation system, the system comprising at least:

[0009] A circulating power generation unit, comprising a compressor, a combustion chamber, and a turbine connected in sequence, wherein the turbine is driven and connected to a generator;

[0010] The working fluid treatment unit is connected to the exhaust end of the circulating power generation unit and is used to recover the heat of the exhaust gas generated by the turbine exhaust port and separate the exhaust gas into condensate and carbon dioxide.

[0011] An electrolytic hydrogen production unit is provided, wherein the inlet of the electrolytic hydrogen production unit is connected to the working fluid treatment unit through a water supply pipeline to receive at least a portion of the condensate as raw water, and the electrolytic hydrogen production unit uses electrical energy to electrolyze water to produce hydrogen and oxygen.

[0012] An oxygen supply pipeline is provided, through which the oxygen outlet of the electrolytic hydrogen production unit is connected to the inlet of the compressor, for supplying at least a portion of the oxygen as an oxidant to the circulating power generation unit;

[0013] A methanol production and storage unit is provided, wherein the methanol production and storage unit is connected to the hydrogen outlet of the electrolytic hydrogen production unit and the carbon dioxide outlet of the working fluid processing unit, respectively, for producing and storing methanol using at least a portion of the hydrogen and at least a portion of the carbon dioxide as raw materials; wherein the methanol outlet of the methanol production and storage unit is connected to the combustion chamber, for conveying at least a portion of the produced methanol to the combustion chamber as fuel.

[0014] Preferably, the working fluid processing unit includes a regenerator, an economizer, and a separator arranged sequentially along the working fluid flow direction;

[0015] The turbine's exhaust port is connected to the hot-side inlet of the regenerator, the regenerator's hot-side outlet is connected to the heating-side inlet of the economizer, and the economizer's heating-side outlet is connected to the inlet of the separator. The separator is used to separate the exhaust gas into carbon dioxide and condensate, and the separator is provided with a carbon dioxide outlet and a condensate outlet.

[0016] Preferably, the condensate outlet of the separator is connected to a water storage device, and the outlet of the water storage device is connected to the electrolysis hydrogen production unit through the water supply pipeline.

[0017] Preferably, a water treatment device is installed on the water supply pipeline, and the downstream of the water treatment device is connected in series with the heating side of the economizer. The water in the water storage device is processed by the water treatment device and preheated by the heating side of the economizer before being input into the electrolytic hydrogen production unit.

[0018] Preferably, a humidifier is provided on the oxygen supply pipeline. The humidifier is used to humidify the oxygen delivered to the compressor, and the drain outlet at the bottom of the humidifier is connected to the water storage device through a humidification return water pipeline.

[0019] Preferably, the system further includes a carbon dioxide reinjection pipeline and a carbon dioxide storage device; the carbon dioxide reinjection pipeline is used to connect the carbon dioxide outlet of the working fluid processing unit to the combustion chamber, and is used to reinject at least a portion of the separated carbon dioxide into the combustion chamber; the carbon dioxide storage device is connected to the carbon dioxide outlet of the working fluid processing unit, and the carbon dioxide storage device is used to seal excess carbon dioxide.

[0020] Preferably, the combustion chamber is further connected to an external fuel supply pipeline, which supplies external fuel to the combustion chamber; and / or, the inlet of the combustion chamber is also connected to the hydrogen outlet of the electrolysis hydrogen production unit, and at least a portion of the hydrogen is input into the combustion chamber as fuel.

[0021] Preferably, the system further includes an oxygen buffer tank, a hydrogen buffer tank, and a carbon dioxide buffer tank;

[0022] The oxygen buffer tank is installed on the oxygen supply pipeline; the hydrogen buffer tank is installed on the pipeline between the hydrogen outlet of the electrolytic hydrogen production unit and the methanol production and storage unit; the carbon dioxide buffer tank is installed on the supply pipeline of the carbon dioxide outlet of the working fluid processing unit.

[0023] The present invention also provides an operation method for the above-mentioned integrated green hydrogen-methanol production cycle power generation system, the operation method comprising the following steps:

[0024] In the circulating power generation unit, oxygen and fuel are burned in the combustion chamber, and the resulting high-temperature and high-pressure working fluid drives the turbine to do work and drives the generator to generate electricity;

[0025] The exhaust gas discharged from the turbine enters the working fluid treatment unit, which recovers the heat of the exhaust gas and separates the exhaust gas into carbon dioxide and condensate.

[0026] At least a portion of the condensate separated by the working fluid treatment unit is transported to the electrolytic hydrogen production unit, which uses electrical energy to electrolyze water to produce hydrogen and oxygen.

[0027] Oxygen is produced and used as an oxidant, which is then delivered to the combustion chamber to participate in combustion.

[0028] At least a portion of the carbon dioxide separated by the working fluid processing unit and at least a portion of the hydrogen produced by the electrolytic hydrogen production unit are supplied to the methanol production and storage unit to produce and store methanol.

[0029] At least a portion of the methanol produced is supplied as fuel to the combustion chamber, and at the same time, at least a portion of the hydrogen produced by the electrolytic hydrogen production unit is also supplied as fuel to the combustion chamber.

[0030] Preferably, during the process of delivering the produced oxygen as an oxidant to the combustion chamber, at least a portion of the delivered oxygen is humidified.

[0031] Preferably, at least a portion of the carbon dioxide separated by the working fluid processing unit is reinjected into the combustion chamber to regulate the outlet temperature of the combustion chamber.

[0032] As described above, the integrated green hydrogen-methanol production cycle power generation system and its operation method of the present invention have the following beneficial effects:

[0033] The system in this invention achieves efficient synergy by integrating a circulating power generation unit, an electrolytic hydrogen production unit, and a green methanol production and storage unit. It deeply recovers waste gas materials and energy generated by the gas turbine circulating power generation unit, achieving zero-carbon emission power generation and fundamentally solving the dependence of traditional advanced power generation systems on high-energy-consuming air separation units. The system uses an electrolytic hydrogen production unit to meet the hydrogen and oxygen supply needs of the entire system, with the byproduct oxygen replacing oxygen production in the air separation unit, effectively reducing the net energy consumption of the entire system and significantly improving net power generation efficiency. The system also introduces a green methanol production and storage unit and innovatively combines the carbon dioxide generated by the circulating power generation unit with the electrolytic hydrogen production and storage unit. The hydrogen produced by the hydrogen production unit is used to synthesize green methanol. Methanol storage replaces electricity storage, realizing carbon recycling and chemical energy storage. At the same time, it also efficiently solves the problems of renewable energy consumption and power load regulation, improves the overall energy efficiency and adaptability of the system, and has a certain degree of power supply flexibility. In addition, by using the waste heat of the exhaust gas from the turbine in a cascade manner to preheat oxygen and water, and introducing a humidifier to humidify the oxygen before it is sent into the combustion chamber, water vapor is used to regulate the combustion temperature and working fluid flow rate, thereby flexibly and quickly adjusting the output of the gas turbine within a small range, and thus achieving deep energy recovery and synergistic optimization of the overall thermal efficiency of the system.

[0034] This invention constructs a highly flexible, fuel-adaptive, and near-zero carbon emission combined heat and power (CHP) energy system. By configuring multi-fuel combustion chambers and corresponding fuel supply paths, it can flexibly use various fuels such as natural gas, hydrogen, or self-produced methanol according to the supply situation, greatly expanding the application scenarios and fuel adaptability. By setting up oxygen buffer tanks, hydrogen buffer tanks, and carbon dioxide buffer tanks, and cooperating with humidification circulation and carbon dioxide reinjection and other adjustment methods, the entire system has the ability to quickly respond to load changes and precisely control combustion temperature. The operational stability and flexibility are significantly improved. The system realizes a closed-loop and cascaded utilization of materials and energy from power generation, carbon capture to green fuel synthesis, and achieves synergistic optimization of comprehensive energy utilization efficiency, economy, and operational reliability. Attached Figure Description

[0035] Figure 1 The diagram shown is a schematic representation of a circular power generation system integrating green hydrogen-methanol production in a specific embodiment of the present invention.

[0036] Figure 2 The diagram shown is a process flow chart of the integrated green hydrogen-methanol production cycle power generation system in a specific embodiment of the present invention.

[0037] Icon labels:

[0038] 1. Compressor; 2. High-pressure gas control valve; 3. Regenerator; 4. Combustion chamber; 5. Turbine; 6. Generator; 7. Economizer; 8. Exhaust gas control valve; 9. Separator; 10. Separated water control valve; 11. Water storage device; 12. First water supply power valve; 13. Water treatment device; 14. Three-way reversing valve; 15. Electrolysis hydrogen production unit; 16. Oxygen buffer tank; 17. Oxygen humidification control valve; 18. Humidifier; 19. First oxygen inlet connection control valve; 20. Return water control valve; 21. Hydrogen buffer tank; 22. First hydrogen conveyor... 23. Methanol production and storage unit; 24. Second hydrogen delivery control valve; 25. Carbon dioxide power valve; 26. Carbon dioxide buffer tank; 27. First carbon dioxide delivery control valve; 28. Compressor; 29. ​​Second carbon dioxide delivery control valve; 30. Methanol delivery power valve; 31. External water source; 32. Second water replenishment power valve; 33. External fuel supply device; 34. External fuel delivery ball valve; 35. Second oxygen inlet connection control valve; 36. Third carbon dioxide delivery control valve; 37. Carbon dioxide storage device. Detailed Implementation

[0039] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0040] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0041] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0042] Please see Figure 1 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0043] Example 1

[0044] This embodiment provides an integrated green hydrogen-methanol production cycle power generation system, which includes at least a cycle power generation unit, a working fluid processing unit, an electrolytic hydrogen production unit 15, an oxygen supply pipeline, and a methanol production and storage unit 23.

[0045] The circulating power generation unit includes a compressor 1, a combustion chamber 4 and a turbine 5 connected in sequence, and the turbine 5 drives and connects to a generator 6.

[0046] The working fluid treatment unit is connected to the exhaust end of the circulating power generation unit to recover the heat of the exhaust gas generated by the turbine 5 exhaust port and to separate the exhaust gas into condensate and carbon dioxide.

[0047] The inlet of the electrolytic hydrogen production unit 15 is connected to the working fluid treatment unit through a water supply pipeline to receive at least a portion of the condensate as raw water. The electrolytic hydrogen production unit 15 uses electrical energy to electrolyze water to produce hydrogen and oxygen.

[0048] The oxygen outlet of the electrolytic hydrogen production unit 15 is connected to the inlet of the compressor 1 through the oxygen supply pipeline, and is used to deliver at least a portion of the oxygen as an oxidant to the circulating power generation unit.

[0049] The methanol production and storage unit 23 is connected to the hydrogen outlet of the electrolytic hydrogen production unit 15 and the carbon dioxide outlet of the working fluid processing unit, respectively, for producing and storing methanol using at least a portion of the hydrogen and at least a portion of the carbon dioxide as raw materials; wherein, the methanol outlet of the methanol production and storage unit 23 is connected to the combustion chamber 4, for transporting at least a portion of the produced methanol as fuel to the combustion chamber 4.

[0050] Specifically, the circulating power generation unit is the core of the system, employing a semi-closed cycle with oxygen as the primary oxidant. Compressor 1 compresses the input oxygen to increase its pressure and temperature. The oxygen is then transported to the fuel chamber, where it mixes with and burns with the fuel, producing high-temperature, high-pressure flue gas. This flue gas expands and performs work, driving turbine 5 to rotate. The output shaft of turbine 5 is connected to generator 6, which in turn drives generator 6 to generate electricity. The working fluid treatment unit not only recovers a large amount of waste heat carried in the exhaust gas—heat collected by the system and reused in other stages, significantly improving overall efficiency—but also cools the exhaust gas and separates it from liquid. The electrolysis hydrogen production unit 15 uses the condensate generated by the system itself to electrolyze hydrogen and oxygen, achieving the recycling of water resources within the system, requiring little or no external water replenishment. The generated oxygen is returned to the inlet of compressor 1 in the circulating power generation unit via an oxygen supply pipeline, serving as the oxidant for combustion. This directly replaces the high-energy-consuming and high-cost air separation device in traditional pure oxygen combustion systems. The carbon source of the methanol production and storage unit 23 comes from the high-purity carbon dioxide separated by the working fluid processing unit, and the hydrogen source comes from the hydrogen produced by the electrolytic hydrogen production unit 15. The two are synthesized into methanol through catalytic hydrogenation reaction. A portion of the methanol is transported to the combustion chamber 4 as fuel, and the excess methanol is stored. The methanol in the methanol production and storage unit 23 is introduced into the combustion chamber as fuel through the methanol delivery power valve 30.

[0051] As an example, the working fluid processing unit includes a regenerator 3, an economizer 7, and a separator 9 arranged sequentially along the working fluid flow direction;

[0052] The exhaust port of the turbine 5 is connected to the hot side inlet of the regenerator 3, the hot side outlet of the regenerator 3 is connected to the heating side inlet of the economizer 7, the heating side outlet of the economizer 7 is connected to the inlet of the separator 9, the separator 9 is used to separate the exhaust gas into carbon dioxide and condensate, and the separator 9 is provided with a carbon dioxide outlet and a condensate outlet.

[0053] Specifically, the exhaust gas from power generation is discharged from turbine 5 at a still very high temperature. This high-temperature exhaust gas first enters the hot side of regenerator 3 (i.e., the side through which the fluid, as the heat source, flows), releasing the high-quality, high-temperature heat it carries to heat the fluid on the other side. In a specific embodiment of the invention, see [reference needed]. Figure 1The other side of the regenerator 3 is connected in series in the pipeline between the compressor 1 and the combustion chamber 4. The outlet of the compressor 1 is connected to the cold-side inlet of the regenerator 3, and the cold-side outlet of the regenerator 3 is connected to the combustion chamber 4. The oxygen introduced into the compressor 1 is compressed and then enters the regenerator 3. The heat in the regenerator 3 heats the oxygen, thereby significantly increasing the temperature of the oxygen entering the combustion chamber 4 and improving the cycle efficiency. Preferably, a high-pressure gas control valve 2 is also installed in the pipeline between the compressor 1 and the regenerator 3 to regulate the airflow.

[0054] After passing through the regenerator 3, the temperature of the exhaust gas has been significantly reduced, but it still retains residual heat. The exhaust gas, after its initial cooling, then enters the heating side of the economizer 7. In the economizer 7, the exhaust gas is further cooled, releasing medium- and low-temperature heat. After two stages of heat exchange, the temperature of the exhaust gas has dropped to near or at the dew point temperature of water vapor. It then enters the separator 9 for further cooling or pressure regulation, where the water vapor condenses into water, and the gaseous carbon dioxide is separated from the water.

[0055] In a specific embodiment of the present invention, an exhaust gas control valve 8 is also provided between the heating side outlet of the economizer 7 and the inlet of the separator 9.

[0056] As an example, the condensate outlet of the separator 9 is connected to a water storage device 11, and the outlet of the water storage device 11 is connected to the electrolysis hydrogen production unit 15 through the water supply pipeline.

[0057] Specifically, liquid water is discharged from the condensate outlet of separator 9 and enters the water storage device 11. Then, the liquid water is supplied to the electrolytic hydrogen production unit 15 through the water supply pipeline. A separation water control valve 10 is installed on the pipeline between the condensate outlet of separator 9 and the water storage device 11, and a first water replenishment power valve 12 is installed on the water supply pipeline.

[0058] In a specific embodiment of the present invention, the inlet end of the water storage device 11 is also connected to an external water source 31. When the water in the water storage device 11 is insufficient, the external water source 31 can replenish it in time. A second water replenishment power valve 32 is provided on the connecting pipeline between the external water source 31 and the water storage device 11.

[0059] As an example, a water treatment device 13 is installed on the water supply pipeline. The downstream of the water treatment device 13 is connected in series with the heating side of the economizer 7. The water in the water storage device 11 is processed by the water treatment device 13 and preheated by the heating side of the economizer 7 before being input into the electrolytic hydrogen production unit 15.

[0060] Specifically, the water in the water storage device 11 is transported to the water treatment device 13 for treatment through the first water replenishment power valve 12. The treated water passes through the economizer 7, and the medium and low temperature heat released in the economizer 7 is used to heat the water leading to the electrolysis hydrogen production unit 15. This is the second stage of energy cascade utilization, which uses waste heat in the production process and reduces external energy consumption.

[0061] As an example, a humidifier 18 is provided on the oxygen supply pipeline. The humidifier 18 is used to humidify the oxygen supplied to the compressor 1, and the drain outlet at the bottom of the humidifier 18 is connected to the water storage device 11 through a humidification return water pipeline.

[0062] Specifically, the oxygen supply pipeline is located between the oxygen outlet of the electrolysis hydrogen production unit 15 and the inlet of the compressor 1, see [reference]. Figure 1 It includes a first oxygen supply pipeline and a second oxygen supply pipeline. The first oxygen supply pipeline is equipped with a humidifier 18, and an oxygen humidification control valve 17 is also provided at the front end of the oxygen entering the humidifier 18. The oxygen enters the humidifier 18 for humidification and is then delivered to the compressor 1. The second oxygen supply pipeline is used as a pipeline for supplementing oxygen and does not need to pass through the humidifier 18.

[0063] In a specific embodiment of the present invention, a first oxygen inlet connection control valve 19 is provided between the first oxygen supply pipeline at the outlet end of the humidifier 18 and the compressor 1, and a second oxygen inlet connection control valve 35 is provided on the second oxygen supply pipeline.

[0064] In a specific embodiment of the present invention, the water used in the humidifier 18 is sourced from the water storage device 11. A three-way reversing valve 14 is provided between the heated side outlet of the economizer 7 and the electrolytic hydrogen production unit 15. The inlet of the three-way reversing valve 14 is connected to the heated side outlet of the economizer 7, one outlet of the three-way reversing valve 14 is connected to the electrolytic hydrogen production unit 15, and the other outlet is connected to the humidifier 18. The water humidifies the oxygen in the humidifier 18, and the condensed water returns to the water storage device 11 through the drain outlet at the bottom of the humidifier 18 and the humidification return water pipeline. A return water control valve 20 is also provided on the humidification return water pipeline.

[0065] As an example, the system further includes a carbon dioxide reinjection pipeline and a carbon dioxide storage device 37; the carbon dioxide reinjection pipeline is used to connect the carbon dioxide outlet of the working fluid processing unit to the combustion chamber 4, and is used to reinject at least a portion of the separated carbon dioxide into the combustion chamber 4; the carbon dioxide storage device 37 is connected to the carbon dioxide outlet of the working fluid processing unit, and the carbon dioxide storage device 37 is used to seal excess carbon dioxide.

[0066] In a specific embodiment of the present invention, the carbon dioxide separated by the separator 9 is transported to the carbon dioxide buffer tank 26 via the carbon dioxide power valve 25. Part of it is transported to the methanol production and storage unit 23 as a carbon source via the first carbon dioxide delivery control valve 27, and part of it is transported to the combustion chamber 4 via the second carbon dioxide delivery control valve 29 on the carbon dioxide reinjection pipeline to participate in combustion. The remaining part is transported to the carbon dioxide storage device 37 for storage via the third carbon dioxide delivery control valve 36. By controlling the flow rate of reinjected carbon dioxide, the outlet temperature of the combustion chamber 4 is reduced, and the outlet temperature of the combustion chamber 4 (inlet of the turbine 5) is controlled within the range that the high-temperature component materials can withstand.

[0067] Preferably, a compressor 28 is also provided on the carbon dioxide reinjection pipeline, and the carbon dioxide enters the combustion chamber 4 after being compressed by the compressor 28.

[0068] As an example, the combustion chamber 4 is also connected to an external fuel supply line that supplies external fuel to the combustion chamber 4; and / or, the inlet of the combustion chamber 4 is also connected to the hydrogen outlet of the electrolysis hydrogen production unit 15, and at least a portion of the hydrogen is input into the combustion chamber 4 as fuel.

[0069] Specifically, the combustion chamber 4 is a multi-fuel combustion chamber 4. An external fuel supply pipeline supplies external fuel, such as natural gas, to the combustion chamber 4. Of course, other fuels that are easy to store and transport can also be used. The hydrogen produced by the electrolysis hydrogen production unit 15 in this system can also be transported to the combustion chamber 4 as fuel.

[0070] In a specific embodiment of the present invention, an external fuel delivery ball valve 34 is provided on the external fuel supply pipeline.

[0071] As an example, the system also includes an oxygen buffer tank 16, a hydrogen buffer tank 21, and a carbon dioxide buffer tank 26;

[0072] The oxygen buffer tank 16 is installed on the oxygen supply pipeline; the hydrogen buffer tank 21 is installed on the pipeline between the hydrogen outlet of the electrolytic hydrogen production unit 15 and the methanol production and storage unit 23; the carbon dioxide buffer tank 26 is installed on the supply pipeline of the carbon dioxide outlet of the working fluid processing unit.

[0073] Specifically, an oxygen buffer tank 16 is added to the oxygen outlet of the electrolytic hydrogen production unit 15, and a hydrogen buffer tank 21 is added to the hydrogen outlet to stabilize the gas outlet flow rate. The outlet end of the oxygen buffer tank 16 leads to a first oxygen supply pipeline and a second oxygen supply pipeline, and the oxygen flow rate is adjusted by setting control valves respectively. The hydrogen in the hydrogen buffer tank 21 is introduced into the methanol production and storage unit 23 through the first hydrogen delivery control valve 22, and is delivered to the combustion chamber 4 for use as fuel through the second hydrogen delivery control valve 24. The carbon dioxide discharged from the carbon dioxide outlet of the separator 9 is introduced into the carbon dioxide buffer tank 26 under the carbon dioxide power valve 25. Part of the carbon dioxide is introduced into the methanol production and storage unit 23 for use as raw material carbon, part of it is compressed by the compressor 28 and enters the combustion chamber 4, and the remaining carbon dioxide is sealed in the carbon dioxide storage device 37.

[0074] Example 2

[0075] See Figure 2 This embodiment provides an operation method for an integrated green hydrogen-methanol production cycle power generation system, the operation method including the following steps:

[0076] S1. Power generation: In the circulating power generation unit, oxygen and fuel are burned in the combustion chamber 4, and the generated high-temperature and high-pressure working fluid drives the turbine 5 to do work and drives the generator 6 to generate electricity.

[0077] Specifically, the oxygen (including dry oxygen and humidified oxygen) compressed by the compressor 1 is preheated by the regenerator 3 and then enters the combustion chamber 4 to undergo pure oxygen or oxygen-enriched combustion with fuel (one or more of the following: external fuel from the external fuel supply device 33, hydrogen produced from the electrolytic hydrogen production unit 15, or methanol from the methanol production and storage unit 23). The high-temperature and high-pressure flue gas produced drives the turbine 5 to do work, which in turn drives the generator 6 to generate electricity.

[0078] S2. Waste heat recovery and carbon and water separation: The exhaust gas discharged from the turbine 5 enters the working fluid treatment unit, which recovers the heat of the exhaust gas and separates the exhaust gas to obtain carbon dioxide and condensate.

[0079] Specifically, the high-temperature exhaust gas after work enters the hot side of the regenerator 3 in the working fluid treatment unit to recover high-temperature heat for preheating cold oxygen. Then it enters the economizer 7 to further recover medium and low-temperature heat, and then enters the separator 9 to separate carbon dioxide and condensate.

[0080] S3, Water circulation and electrolysis hydrogen production: At least a portion of the condensate separated by the working fluid treatment unit is transported to the electrolysis hydrogen production unit 15, which uses electrical energy to electrolyze water to produce hydrogen and oxygen.

[0081] Specifically, the separated condensate is stored in the water storage device 11, purified by the water treatment device 13, preheated by the heating side of the economizer 7, and then sent to the electrolysis hydrogen production unit 15 for electrolysis to produce hydrogen and oxygen.

[0082] S4, Oxygen Closed Loop: Produced oxygen is delivered to the combustion chamber 4 as an oxidant to participate in combustion;

[0083] As an example, during the process of delivering the produced oxygen as an oxidant to the combustion chamber 4, at least a portion of the delivered oxygen is humidified.

[0084] Specifically, after the generated oxygen enters the oxygen buffer tank 16, part of it is directly used as dry oxygen supply, and part of it is humidified by the humidifier 18 and used as wet oxygen supply. Both are delivered to the combustion chamber 4 by the compressor 1 to complete the oxygen closed loop. At this time, the moisture content of the oxygen can be changed by adjusting the oxygen humidification control valve 17, so as to achieve fine adjustment of the gas turbine output and control of the combustion temperature.

[0085] S5, Green Methanol Production and Storage Unit 23: At least a portion of the carbon dioxide separated by the working fluid processing unit and at least a portion of the hydrogen produced by the electrolytic hydrogen production unit 15 are supplied to the methanol production and storage unit 23 to produce and store methanol.

[0086] As an example, at least a portion of the carbon dioxide separated by the working fluid processing unit is reinjected into the combustion chamber 4 to regulate the outlet temperature of the combustion chamber 4.

[0087] Specifically, the self-produced hydrogen and captured carbon dioxide are synthesized into methanol under suitable conditions and stored. In addition, excess carbon dioxide can be reinjected into the combustion chamber 4 for temperature control or transported to the carbon dioxide storage device 37 for sealing.

[0088] S6. Flexible fuel supply: At least a portion of the produced methanol is supplied as fuel to the combustion chamber 4, and at the same time, at least a portion of the hydrogen produced by the electrolytic hydrogen production unit 15 is also supplied as fuel to the combustion chamber 4.

[0089] In a specific embodiment of the present invention, it is also necessary to dynamically adjust the operating power of the electrolytic hydrogen production unit 15, the amount of hydrogen and carbon dioxide delivered to the methanol production and storage unit 23, and the amount of hydrogen and methanol delivered to the combustion chamber 4 according to the power demand, so as to balance the energy and material distribution between power generation, hydrogen production and methanol production and pure storage.

[0090] In addition, the fuel supplied to the combustion chamber 4 includes one or a combination of self-produced methanol, hydrogen and external fuel supplied by external fuel supply device 33, and is switched or mixed according to the supply situation.

[0091] In summary, the system of this invention achieves zero-carbon emission power generation by efficiently coordinating an integrated circulating power generation unit, an electrolytic hydrogen production unit, and a green methanol production and storage unit. It deeply recovers the waste gas materials and energy generated by the gas turbine circulating power generation unit, fundamentally solving the dependence of traditional advanced power generation systems on high-energy-consuming air separation units. The system uses an electrolytic hydrogen production unit to meet the hydrogen and oxygen supply needs of the entire system, with the byproduct oxygen replacing oxygen production in the air separation unit, effectively reducing the net energy consumption of the entire system and significantly improving net power generation efficiency. Furthermore, the introduction of a green methanol production and storage unit innovatively utilizes the carbon dioxide generated by the circulating power generation unit. The hydrogen produced by the electrolysis hydrogen production unit is used to synthesize green methanol, and methanol storage replaces electricity storage. This achieves carbon recycling and chemical energy storage, while also efficiently solving the problems of renewable energy consumption and power load regulation, improving the overall energy efficiency and adaptability of the system, and providing a certain degree of power supply flexibility. In addition, by using the waste heat from the turbine exhaust gas in a cascade manner to preheat oxygen and water, and introducing a humidifier to humidify the oxygen before it is sent into the combustion chamber, water vapor is used to regulate the combustion temperature and working fluid flow rate, thereby flexibly and quickly adjusting the gas turbine output within a small range, and thus achieving deep energy recovery and synergistic optimization of the overall thermal efficiency of the system. This invention constructs a highly flexible, fuel-adaptive, and near-zero carbon emission combined heat and power (CHP) energy system. By configuring multi-fuel combustion chambers and corresponding fuel supply paths, it can flexibly use various fuels such as natural gas, hydrogen, or self-produced methanol depending on the supply situation, greatly expanding its application scenarios and fuel adaptability. By setting up oxygen buffer tanks, hydrogen buffer tanks, and carbon dioxide buffer tanks, and cooperating with humidification circulation and carbon dioxide reinjection, the entire system has the ability to quickly respond to load changes and precisely control combustion temperature, significantly improving operational stability and flexibility. This system realizes a closed-loop and cascaded utilization of materials and energy from power generation, carbon capture to green fuel synthesis, achieving synergistic optimization of comprehensive energy utilization efficiency, economy, and operational reliability. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial application value.

[0092] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A circular power generation system integrating green hydrogen-methanol production, characterized in that, The system includes at least: A circulating power generation unit, comprising a compressor, a combustion chamber, and a turbine connected in sequence, wherein the turbine is driven and connected to a generator; The working fluid treatment unit is connected to the exhaust end of the circulating power generation unit and is used to recover the heat of the exhaust gas generated by the turbine exhaust port and separate the exhaust gas into condensate and carbon dioxide. An electrolytic hydrogen production unit is provided, wherein the inlet of the electrolytic hydrogen production unit is connected to the working fluid treatment unit through a water supply pipeline to receive at least a portion of the condensate as raw water, and the electrolytic hydrogen production unit uses electrical energy to electrolyze water to produce hydrogen and oxygen. An oxygen supply pipeline is provided, through which the oxygen outlet of the electrolytic hydrogen production unit is connected to the inlet of the compressor, for supplying at least a portion of the oxygen as an oxidant to the circulating power generation unit; A methanol production and storage unit is provided, wherein the methanol production and storage unit is connected to the hydrogen outlet of the electrolytic hydrogen production unit and the carbon dioxide outlet of the working fluid processing unit, respectively, for producing and storing methanol using at least a portion of the hydrogen and at least a portion of the carbon dioxide as raw materials; wherein the methanol outlet of the methanol production and storage unit is connected to the combustion chamber, for conveying at least a portion of the produced methanol to the combustion chamber as fuel.

2. The integrated green hydrogen-methanol production cycle power generation system according to claim 1, characterized in that: The working fluid processing unit includes a regenerator, an economizer, and a separator arranged sequentially along the working fluid flow direction. The turbine's exhaust port is connected to the hot-side inlet of the regenerator, the regenerator's hot-side outlet is connected to the heating-side inlet of the economizer, and the economizer's heating-side outlet is connected to the inlet of the separator. The separator is used to separate the exhaust gas into carbon dioxide and condensate, and the separator is provided with a carbon dioxide outlet and a condensate outlet.

3. The integrated green hydrogen-methanol production cycle power generation system according to claim 2, characterized in that: The condensate outlet of the separator is connected to a water storage device, and the outlet of the water storage device is connected to the electrolytic hydrogen production unit through the water supply pipeline.

4. The integrated green hydrogen-methanol production cycle power generation system according to claim 3, characterized in that: A water treatment device is installed on the water supply pipeline. The downstream of the water treatment device is connected in series with the heating side of the economizer. The water in the water storage device is processed by the water treatment device and preheated by the heating side of the economizer before being input into the electrolytic hydrogen production unit.

5. The integrated green hydrogen-methanol production cycle power generation system according to claim 3, characterized in that: A humidifier is installed on the oxygen supply pipeline. The humidifier is used to humidify the oxygen delivered to the compressor, and the drain outlet at the bottom of the humidifier is connected to the water storage device through a humidification return water pipeline.

6. The integrated green hydrogen-methanol production cycle power generation system according to claim 1, characterized in that: The system also includes a carbon dioxide reinjection pipeline and a carbon dioxide storage device; the carbon dioxide reinjection pipeline is used to connect the carbon dioxide outlet of the working fluid processing unit to the combustion chamber, and is used to reinject at least a portion of the separated carbon dioxide into the combustion chamber; the carbon dioxide storage device is connected to the carbon dioxide outlet of the working fluid processing unit, and the carbon dioxide storage device is used to seal excess carbon dioxide.

7. The integrated green hydrogen-methanol production cycle power generation system according to claim 1, characterized in that: The combustion chamber is also connected to an external fuel supply pipeline, which supplies external fuel to the combustion chamber; and / or, the inlet of the combustion chamber is also connected to the hydrogen outlet of the electrolysis hydrogen production unit, and at least a portion of the hydrogen is input into the combustion chamber as fuel.

8. The integrated green hydrogen-methanol production cycle power generation system according to any one of claims 1 to 7, characterized in that: The system also includes an oxygen buffer tank, a hydrogen buffer tank, and a carbon dioxide buffer tank; The oxygen buffer tank is installed on the oxygen supply pipeline; the hydrogen buffer tank is installed on the pipeline between the hydrogen outlet of the electrolytic hydrogen production unit and the methanol production and storage unit; the carbon dioxide buffer tank is installed on the supply pipeline of the carbon dioxide outlet of the working fluid processing unit.

9. A method for operating an integrated green hydrogen-methanol production cycle power generation system as described in any one of claims 1 to 8, characterized in that: The operating method includes the following steps: In the circulating power generation unit, oxygen and fuel are burned in the combustion chamber, and the resulting high-temperature and high-pressure working fluid drives the turbine to do work and drives the generator to generate electricity; The exhaust gas discharged from the turbine enters the working fluid treatment unit, which recovers the heat of the exhaust gas and separates the exhaust gas into carbon dioxide and condensate. At least a portion of the condensate separated by the working fluid treatment unit is transported to the electrolytic hydrogen production unit, which uses electrical energy to electrolyze water to produce hydrogen and oxygen. Oxygen is produced and used as an oxidant, which is then delivered to the combustion chamber to participate in combustion. At least a portion of the carbon dioxide separated by the working fluid processing unit and at least a portion of the hydrogen produced by the electrolytic hydrogen production unit are supplied to the methanol production and storage unit to produce and store methanol. At least a portion of the methanol produced is supplied as fuel to the combustion chamber, and at the same time, at least a portion of the hydrogen produced by the electrolytic hydrogen production unit is also supplied as fuel to the combustion chamber.

10. The operating method according to claim 9, characterized in that: The operating method also includes one or a combination of the following conditions: During the process of delivering the produced oxygen as an oxidant to the combustion chamber, at least a portion of the delivered oxygen is humidified. At least a portion of the carbon dioxide separated by the working fluid processing unit is reinjected into the combustion chamber to regulate the outlet temperature of the combustion chamber.

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