A wind-solar-electric-hydrogen-alcohol multi-purpose integrated new energy large base system and operation method

Abstract

The present application belongs to the field of new energy power generation, energy storage peak shaving technology and fuel cell power generation technology, and particularly relates to a wind-solar-hydrogen-methanol multi-energy fusion new energy large base system and a running method. The system comprises a new energy power generation and power regulation subsystem, a lithium battery energy storage main peak shaving subsystem, a mixed water electrolysis subsystem, a green methanol synthesis and energy storage subsystem, a methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation subsystem, a tail gas waste heat recovery and catalytic combustion heating subsystem, and a carbon water recovery and circulation subsystem. The method collects, adjusts and distributes new energy power, uses surplus power to produce hydrogen by PEM-ALK collaborative electrolysis to synthesize methanol for storage, uses methanol reforming fuel cells to generate power when lithium battery energy storage is insufficient, and couples the heat of the stack waste heat and catalytic combustion to provide heat for methanol reforming, while recycling and reusing carbon dioxide and water. The present application improves the power supply stability, new energy consumption capacity and resource utilization efficiency of the energy base.

Description

Technical Field

[0001] This invention belongs to the fields of new energy power generation, energy storage peak shaving technology and fuel cell power generation technology, and particularly relates to a new energy large-scale base system and operation method that integrates wind, solar and hydrogen alcohol. Background Technology

[0002] Against the backdrop of escalating global ecological and environmental problems, the shift from a fossil fuel-dominated to a clean energy-dominated energy system has become a consensus. Wind and solar energy, as typical renewable energy sources, are clean, environmentally friendly, widely distributed, and abundant. Constructing large-scale energy bases in deserts, Gobi, and wastelands rich in wind and solar resources is of great significance for increasing the proportion of non-fossil energy supply and promoting the construction of a low-carbon energy system.

[0003] However, wind and solar energy are constrained by the natural environment, resulting in issues such as randomness, fluctuation, and intermittency in power output. When the output of new energy sources does not match the power demand of the grid, it will affect the stable operation of the grid and lead to wind and solar curtailment. The existing power system often relies on thermal power units or pumped storage for peak shaving, but thermal power peak shaving is inconsistent with the goal of green and low-carbon development, while pumped storage is greatly limited by geographical conditions.

[0004] Lithium-ion battery energy storage features fast response, high regulation precision, and flexible charging and discharging, making it suitable for smoothing short-term fluctuations in renewable energy output and rapidly compensating for grid power shortages. It is a primary peak-shaving method for large-scale renewable energy bases. However, when the surplus renewable energy lasts for an extended period, or when lithium-ion battery energy storage units reach their charging power or state-of-charge limits, there remains a continuous surplus of renewable energy that cannot be absorbed, leading to wind and solar power curtailment.

[0005] Hydrogen production through water electrolysis can convert surplus wind and solar power into hydrogen chemical energy for storage, representing an important way to improve the utilization of new energy sources. Alkaline water electrolysis has low operating costs and is suitable for handling stable hydrogen production loads, while proton exchange membrane electrolysis offers fast response times and strong adaptability to power fluctuations. Combining these two hydrogen production technologies can effectively balance large-scale hydrogen production with dynamic regulation capabilities. However, hydrogen has limitations in terms of storage and transportation requirements, safety management challenges, and low volumetric energy density, hindering its large-scale energy storage and long-term utilization, and making it difficult to meet the stable power supply needs of large energy bases.

[0006] Methanol, as a hydrogen carrier, offers advantages such as convenient storage and a mature industrial chain. Green methanol can be obtained through the reaction of green hydrogen and carbon dioxide, converting surplus renewable energy into liquid chemical energy. The generated green methanol can be stored as a liquid energy product or used as a raw material for downstream chemical product preparation. However, current technologies lack a systematic solution for deeply coupling lithium-ion battery energy storage, mixed water electrolysis for hydrogen production, methanol synthesis, and methanol reforming fuel cell power generation to achieve synergistic operation of power generation, energy storage, hydrogen production, methanol production, power supply, and resource recovery in large-scale renewable energy bases. Summary of the Invention

[0007] To overcome or alleviate one or more of the above-mentioned technical problems, the purpose of this invention is to provide a multi-energy integrated new energy base system and its operation method that combines wind, solar, hydrogen, and methanol. This system integrates wind and solar renewable energy, lithium battery energy storage for peak shaving, PEM-ALK synergistic electrolysis for hydrogen production, carbon dioxide hydrogenation to synthesize green methanol, methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation, exhaust gas waste heat recovery and catalytic combustion for heating, and carbon dioxide and water recycling. It addresses issues such as large output fluctuations in large-scale wind and solar energy bases, difficulty in long-term absorption of curtailed wind and solar power, and insufficient utilization of carbon and water resources. It also achieves efficient absorption and stable grid connection of new energy power, efficient resource utilization, and improves the system's low-carbon operation level.

[0008] To achieve the above objectives, the first technical solution of this application provides an operation method for a large-scale new energy base system integrating wind, solar, hydrogen, and alcohol energy, including:

[0009] Based on the real-time output power of new energy sources, the grid connection demand power, the state of charge of lithium battery energy storage units, and the system power gap, renewable energy power is collected, regulated, and distributed.

[0010] Hydrogen and oxygen are produced by using surplus renewable energy power through a PEM-ALK co-electrolysis hydrogen production unit. The hydrogen is then sent to a hydrogen storage unit and the oxygen is sent to an electrolysis by-product oxygen buffer and supply unit.

[0011] The hydrogen in the hydrogen storage unit reacts with the carbon dioxide buffer and the carbon dioxide supplied by the supply unit to synthesize methanol, and the methanol is stored in the methanol storage unit.

[0012] When the output power of new energy is lower than the grid connection demand and the lithium battery energy storage unit cannot meet the power gap compensation demand on its own, the methanol in the methanol storage unit is sent to the high-temperature proton exchange membrane fuel cell unit for power generation after methanol reforming and reforming gas conditioning, and then sent to the grid through the power conversion and boost grid connection unit.

[0013] The cathode exhaust gas discharged from the high-temperature proton exchange membrane fuel cell unit is heat-exchanged with the heat transfer medium through the stack waste heat recovery unit. The anode exhaust gas and the oxygen provided by the electrolysis by-product oxygen buffer and supply unit are catalytically combusted in the exhaust gas catalytic combustion and methanol supplementary combustion heating unit, and the heat transfer medium is used to heat the methanol reforming reaction.

[0014] The carbon dioxide in the exhaust gas discharged from the exhaust gas catalytic combustion and methanol supplementary combustion heating unit is captured and returned to the carbon dioxide buffer and supply unit, and the condensate is returned to the pure water storage and supply unit.

[0015] Furthermore, the collection, regulation, and distribution are scheduled according to the principle of primary peak regulation by lithium battery energy storage and auxiliary power replenishment by methanol reforming high-temperature proton exchange membrane fuel cells:

[0016] When the output power of new energy power generation meets the grid connection requirements, new energy power should be connected to the grid first through power conversion and step-up grid connection units;

[0017] When the output power of new energy power generation exceeds the grid connection demand, the surplus power is preferentially allocated to the lithium battery energy storage unit for charging; when the lithium battery energy storage unit reaches the charging power limit, the state of charge reaches the set limit, or the surplus power duration exceeds the set threshold, the remaining surplus power is allocated to the PEM-ALK co-electrolysis hydrogen production unit.

[0018] When the output power of new energy power generation is lower than the grid connection demand, the power gap is compensated by the discharge of lithium battery energy storage units.

[0019] When the lithium battery energy storage unit cannot meet the power deficit compensation requirement on its own, the high-temperature proton exchange membrane fuel cell unit is activated to provide auxiliary power.

[0020] Furthermore, the PEM-ALK co-electrolysis hydrogen production unit includes a PEM electrolysis branch and an ALK electrolysis branch, which are allocated to the corresponding branches according to the characteristics of surplus electricity:

[0021] If the surplus power is a short-term fluctuating surplus power, it will be allocated to the PEM electrolysis branch.

[0022] If the surplus power is a continuous surplus power, it is allocated to the ALK electrolysis branch.

[0023] When surplus power includes both a stable base load portion and a fluctuating increment portion, the stable base load portion is allocated to the ALK electrolysis branch, and the fluctuating increment portion is allocated to the PEM electrolysis branch.

[0024] Furthermore, the methanol synthesis load is dynamically adjusted based on the hydrogen supply flow rate, carbon dioxide reserves, and methanol reserves:

[0025] When the storage capacity of the hydrogen storage unit and the carbon dioxide buffer and supply unit are both higher than the corresponding preset values ​​and the methanol storage capacity of the methanol storage unit is lower than the preset upper limit, the methanol synthesis load is started or increased.

[0026] If any of the hydrogen storage unit or the carbon dioxide buffer and supply unit fails to meet the preset conditions, the methanol synthesis load will be reduced or stopped.

[0027] Furthermore, the feature is that the heat-conducting medium circulates between the fuel cell waste heat recovery unit, the tail gas catalytic combustion and methanol afterburning heating unit, and the methanol reforming and reformed gas conditioning unit, sequentially absorbing the heat released by the cathode tail gas waste heat, catalytic combustion and methanol afterburning, and releasing heat to the methanol reforming reaction.

[0028] Furthermore, through the exhaust gas condensation and CO2 capture and reuse unit, water treatment unit, pure water storage and supply unit, and electrolysis by-product oxygen buffer and supply unit, a carbon dioxide and water recycling path and an internal utilization path for electrolysis by-product oxygen are formed.

[0029] Furthermore, the methanol reforming and reformed gas conditioning unit performs steam reforming of methanol to generate hydrogen-containing reformed gas, and condenses, separates steam and water, regulates temperature, pressure and carbon monoxide concentration of the hydrogen-containing reformed gas to meet the anode inlet requirements of the high-temperature proton exchange membrane fuel cell unit.

[0030] Furthermore, when the calorific value of the anode tail gas is insufficient to meet the heating demand of methanol reforming, methanol is supplemented from the methanol storage unit to the tail gas catalytic combustion and methanol supplementary combustion heating unit for supplementary combustion.

[0031] The second technical solution of this application discloses a large-scale new energy base system for realizing the above-mentioned operation method, which integrates wind, solar, hydrogen, and alcohol energy, including:

[0032] The new energy power generation and power regulation subsystem includes a photovoltaic power generation unit, a wind power generation unit, and a new energy power collection, regulation and distribution unit. Both the photovoltaic power generation unit and the wind power generation unit are connected to the new energy power collection, regulation and distribution unit.

[0033] The lithium battery energy storage main peak-shaving subsystem includes a lithium battery energy storage unit, which is connected to a new energy power collection, regulation and distribution unit and a power conversion and boost grid connection unit.

[0034] The hybrid water electrolysis subsystem includes a pure water storage and supply unit, a PEM-ALK synergistic electrolysis hydrogen production unit, and an electrolysis by-product oxygen buffer and supply unit. The PEM-ALK synergistic electrolysis hydrogen production unit is connected to the new energy power collection, regulation and distribution unit and the pure water storage and supply unit, respectively. The electrolysis by-product oxygen buffer and supply unit is connected to the PEM-ALK synergistic electrolysis hydrogen production unit.

[0035] The green methanol synthesis and energy storage subsystem includes a hydrogen storage unit, a carbon dioxide buffer and supply unit, a methanol synthesis condensation and separation unit, and a methanol storage unit. The hydrogen storage unit is connected to the PEM-ALK co-electrolysis hydrogen production unit. The methanol synthesis condensation and separation unit is connected to the hydrogen storage unit and the carbon dioxide buffer and supply unit, respectively. The methanol storage unit is connected to the methanol synthesis condensation and separation unit.

[0036] A methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation system includes a methanol reforming and reforming gas conditioning unit and a high-temperature proton exchange membrane fuel cell unit. The methanol reforming and reforming gas conditioning unit is connected to a methanol storage unit, a pure water storage and supply unit and the high-temperature proton exchange membrane fuel cell unit, respectively.

[0037] The exhaust gas waste heat recovery and catalytic combustion heating subsystem includes a fuel cell stack waste heat recovery unit, an exhaust gas catalytic combustion and methanol afterburning heating unit, and a heat transfer medium circulation pipeline. The fuel cell stack waste heat recovery unit is connected to the cathode exhaust gas outlet of the high-temperature proton exchange membrane fuel cell unit. The exhaust gas catalytic combustion and methanol afterburning heating unit is connected to the anode exhaust gas outlet, the electrolysis by-product oxygen buffer and supply unit, and the methanol storage unit of the high-temperature proton exchange membrane fuel cell unit, respectively. The heat transfer medium circulation pipeline is connected to the fuel cell stack waste heat recovery unit, the exhaust gas catalytic combustion and methanol afterburning heating unit, and the methanol reforming and reformed gas conditioning unit.

[0038] The carbon and water recovery cycle subsystem includes a tail gas condensation and CO2 capture and reuse unit, a steam condensation and feedwater recovery unit, a water treatment unit, and a carbon dioxide buffer and supply unit. The tail gas condensation and CO2 capture and reuse unit is connected to the tail gas catalytic combustion and methanol supplementary combustion heating unit and the carbon dioxide buffer and supply unit, respectively. The water outlet of the tail gas condensation and CO2 capture and reuse unit is connected to the pure water storage and supply unit through the steam condensation and feedwater recovery unit and the water treatment unit.

[0039] The power conversion and grid-connection unit is connected to the new energy power collection, regulation and distribution unit, the lithium battery energy storage unit, and the high-temperature proton exchange membrane fuel cell unit, respectively.

[0040] Beneficial effects:

[0041] 1. Improved the stability of energy supply in large energy bases: By integrating fluctuating renewable energy sources such as photovoltaic and wind power into new energy power collection, regulation and distribution units, the grid-connected output, energy storage charging and discharging and electrolysis hydrogen production loads are coordinated and regulated, which helps to improve the overall stability and reliability of energy supply in large energy bases when facing the intermittency and fluctuation of renewable energy.

[0042] 2. This invention uses a lithium battery energy storage main peak-shaving subsystem as the primary peak-shaving means, prioritizing the smoothing of short-term power fluctuations and compensation for short-term power gaps in new energy sources, enabling rapid response to peak-shaving demands. The methanol energy storage pathway absorbs surplus electricity, while the methanol reforming high-temperature proton exchange membrane fuel cell is used for auxiliary power generation. When the lithium battery energy storage unit has insufficient state of charge, limited discharge power, or a persistent power gap exists in the grid, the chemical energy stored in methanol is converted into electrical energy through the high-temperature proton exchange membrane fuel cell for output, assisting the energy storage system in peak shaving.

[0043] 3. The PEM-ALK synergistic electrolysis hydrogen production method is adopted: the PEM electrolysis branch is suitable for short-term fluctuations and rapid response conditions of new energy power, while the ALK electrolysis branch is suitable for continuous and stable surplus power conditions. This allows the electrolysis hydrogen production process to select the appropriate hydrogen production method according to the fluctuation of new energy, taking into account the response speed, operational stability and economy of hydrogen production.

[0044] 4. Through a green methanol synthesis and energy storage subsystem, surplus renewable energy power is converted into green methanol. Green methanol can be stored as a liquid energy product, used as a raw material for downstream chemical product preparation, and can also be supplied to a methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation system for auxiliary power generation, depending on system operation requirements. This improves the product utilization and multi-path utilization capabilities of curtailed wind and solar power.

[0045] 5. By using a waste heat recovery and catalytic combustion heating system, the waste heat from the cathode exhaust gas, the chemical energy from the anode exhaust gas, and the heat from methanol combustion in a high-temperature proton exchange membrane fuel cell are coupled and utilized. The heat is then supplied to the methanol reforming process through a heat transfer medium, thereby improving the heat utilization level of the methanol reforming and fuel cell auxiliary power generation processes.

[0046] 6. The system achieves synergistic recovery and recycling of carbon, water, and oxygen resources: The exhaust gas from the tail gas catalytic combustion and methanol supplementary combustion heating unit enters the tail gas condensation and CO2 capture and reuse unit. Here, carbon dioxide, after capture, returns to the carbon dioxide buffer and supply unit for use in the methanol synthesis process. Water vapor in the tail gas, after condensation, enters the condensation and feedwater recovery unit and the water treatment unit, and after purification, returns to the pure water storage and supply unit for use in the mixed electrolysis water subsystem. Simultaneously, oxygen, a byproduct of electrolysis, participates in the catalytic combustion of the fuel cell anode tail gas, improving the overall recycling level of the system. Attached Figure Description

[0047] Figure 1 This is a structural block diagram of a new energy base system that integrates wind, solar, hydrogen, and alcohol energy, as described in this invention.

[0048] In the picture:

[0049] 1-Photovoltaic power generation unit; 2-Wind power generation unit; 3-New energy power collection, regulation and distribution unit; 4-PEM-ALK co-electrolysis hydrogen production unit; 5-Pure water storage and supply unit; 6-Hydrogen storage unit; 7-Electrolysis by-product oxygen buffer and supply unit; 8-Carbon dioxide buffer and supply unit; 9-Methanol synthesis, condensation and separation unit; 10-Methanol storage unit; 11-Methanol reforming and reformate gas conditioning unit; 12-High-temperature proton exchange membrane fuel cell unit; 13-Stack waste heat recovery unit; 14-Tail gas catalytic combustion and methanol supplemental combustion heating unit; 15-Tail gas condensation and CO2 capture and reuse unit; 16-Lithium battery energy storage unit; 17-Power conversion and grid connection unit; 18-Grid; 19-Condensation and feedwater recovery unit; 20-Water treatment unit. Detailed Implementation

[0050] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0051] I. System Overall Architecture

[0052] like Figure 1 As shown, the new energy base system integrating wind, solar, hydrogen, and methanol in this invention includes a new energy power generation and power regulation subsystem, a lithium battery energy storage main peak-shaving subsystem, a mixed water electrolysis subsystem, a green methanol synthesis and energy storage subsystem, a methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation system, a tail gas waste heat recovery and catalytic combustion heating subsystem, and a carbon and water recovery and recycling subsystem.

[0053] The new energy power generation and power regulation subsystem includes a photovoltaic power generation unit 1, a wind power generation unit 2, and a new energy power collection, regulation, and distribution unit 3. The output terminals of both the photovoltaic power generation unit 1 and the wind power generation unit 2 are connected to the new energy power collection, regulation, and distribution unit 3. This subsystem receives new energy power and then distributes and regulates it based on the real-time output power of the new energy source, the grid connection demand, the state of charge of the lithium battery energy storage unit 16, the operating status of the mixed water electrolysis subsystem, and the methanol storage status.

[0054] The lithium battery energy storage main peak-shaving subsystem includes a lithium battery energy storage unit 16. The lithium battery energy storage unit 16 is connected to the new energy power collection, regulation, and distribution unit 3 and the power conversion and grid-connection unit 17, respectively. This subsystem serves as the main peak-shaving means of this system, used to smooth short-term power fluctuations in new energy sources and compensate for short-term power gaps in the power grid.

[0055] The hybrid water electrolysis subsystem includes a pure water storage and supply unit 5, a PEM-ALK synergistic electrolysis hydrogen production unit 4, and an electrolysis by-product oxygen buffering and supply unit 7. The PEM-ALK synergistic electrolysis hydrogen production unit 4 is connected to the new energy power collection, regulation, and distribution unit 3 and the pure water storage and supply unit 5, respectively. The electrolysis by-product oxygen buffering and supply unit 7 is connected to the PEM-ALK synergistic electrolysis hydrogen production unit 4. This subsystem is used to produce hydrogen and oxygen using surplus new energy power.

[0056] The green methanol synthesis and energy storage subsystem includes a hydrogen storage unit 6, a carbon dioxide buffer and supply unit 8, a methanol synthesis condensation and separation unit 9, and a methanol storage unit 10. The hydrogen storage unit 6 is connected to the PEM-ALK co-electrolysis hydrogen production unit 4. The methanol synthesis condensation and separation unit 9 is connected to both the hydrogen storage unit 6 and the carbon dioxide buffer and supply unit 8. The methanol storage unit 10 is connected to the methanol synthesis condensation and separation unit 9. This subsystem is used to react hydrogen and carbon dioxide generated by the mixed water electrolysis subsystem to synthesize and store green methanol.

[0057] The methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation system includes a methanol reforming and reforming gas conditioning unit 11 and a high-temperature proton exchange membrane fuel cell unit 12. The methanol reforming and reforming gas conditioning unit 11 is connected to the methanol storage unit 10, the pure water storage and supply unit 5, and the high-temperature proton exchange membrane fuel cell unit 12, respectively. This subsystem serves as an auxiliary power supply branch after the main peak shaving of the lithium battery energy storage, and is used to generate auxiliary power when the lithium battery energy storage unit 16 cannot meet the power gap compensation requirements.

[0058] The exhaust gas waste heat recovery and catalytic combustion heating subsystem includes a fuel cell stack waste heat recovery unit 13, an exhaust gas catalytic combustion and methanol afterburning heating unit 14, and a heat transfer medium circulation pipeline. The fuel cell stack waste heat recovery unit 13 is connected to the cathode exhaust gas outlet of the high-temperature proton exchange membrane fuel cell unit 12. The exhaust gas catalytic combustion and methanol afterburning heating unit 14 is connected to the anode exhaust gas outlet of the high-temperature proton exchange membrane fuel cell unit 12, the electrolysis by-product oxygen buffer and supply unit 7, and the methanol storage unit 10, respectively. The heat transfer medium circulation pipeline connects the fuel cell stack waste heat recovery unit 13, the exhaust gas catalytic combustion and methanol afterburning heating unit 14, and the methanol reforming and reformate gas conditioning unit 11. This subsystem is used to couple and recover the exhaust gas waste heat and chemical energy of the high-temperature proton exchange membrane fuel cell unit 12 and provide a stable heat source for the methanol reforming reaction.

[0059] The carbon and water recycling subsystem includes a tail gas condensation and CO2 capture and reuse unit 15, a steam condensation and feedwater recovery unit 19, a water treatment unit 20, and a carbon dioxide buffer and supply unit 8. The tail gas condensation and CO2 capture and reuse unit 15 is connected to the tail gas catalytic combustion and methanol afterburning heating unit 14 and the carbon dioxide buffer and supply unit 8, respectively. The water outlet of the tail gas condensation and CO2 capture and reuse unit 15 is connected to the pure water storage and supply unit 5 via the steam condensation and feedwater recovery unit 19 and the water treatment unit 20. This subsystem is used to achieve the recycling of carbon dioxide and water within the system.

[0060] The power conversion and boosting grid connection unit 17 is connected to the new energy power collection, regulation and distribution unit 3, the lithium battery energy storage unit 16 and the high temperature proton exchange membrane fuel cell unit 12, respectively, and is used to convert, stabilize, collect and boost multiple power sources before sending them to the power grid 18.

[0061] II. Operating Method

[0062] The operation method of the new energy base system integrating wind, solar, hydrogen, and alcohol multi-energy integration of the present invention includes the following steps:

[0063] Step 1: Collection, Regulation and Distribution of New Energy Power

[0064] The new energy power collection, regulation and distribution unit 3 receives new energy power from photovoltaic power generation unit 1 and wind power generation unit 2, and distributes the new energy power according to the real-time output power of the new energy, the grid connection demand power, the state of charge of lithium battery energy storage unit 16 and the system power gap.

[0065] When the output power of new energy power generation meets the grid connection requirements, the new energy power is preferentially connected to the grid 18 via the power conversion and step-up grid connection unit 17.

[0066] When the output power of new energy power generation exceeds the grid connection demand, the surplus power is preferentially allocated to the lithium battery energy storage unit 16 for charging. When the lithium battery energy storage unit 16 reaches the upper limit of charging power, the state of charge reaches the set upper limit, or the duration of surplus power exceeds the set threshold, the remaining surplus power is allocated to the PEM-ALK co-electrolysis hydrogen production unit 4.

[0067] When the output power of new energy power generation is lower than the grid connection demand, the lithium battery energy storage unit 16 will be used to compensate for the power gap. When the state of charge of the lithium battery energy storage unit 16 is lower than the set lower limit, the discharge power reaches the set upper limit, the discharge duration exceeds the set threshold, or the lithium battery energy storage unit 16 cannot meet the power gap compensation demand on its own, the methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation system will be started to provide auxiliary power.

[0068] Step 2: PEM-ALK Co-electrolysis for Hydrogen Production

[0069] The PEM-ALK co-electrolysis hydrogen production unit 4 receives pure water from the pure water storage and supply unit 5 and surplus electricity from the new energy power collection, regulation and distribution unit 3 to produce hydrogen through electrolysis. This unit includes a PEM electrolysis branch and an ALK electrolysis branch, which are distributed to the corresponding branches according to the characteristics of the surplus electricity.

[0070] If the surplus power is short-term and fluctuating, it is allocated to the PEM electrolysis branch, utilizing its fast response speed for rapid hydrogen production. If the surplus power is continuous, it is allocated to the ALK electrolysis branch, utilizing its low operating cost for continuous and stable hydrogen production. When the surplus power includes both a stable base load and a fluctuating incremental portion, the stable base load portion is allocated to the ALK electrolysis branch, and the fluctuating incremental portion is allocated to the PEM electrolysis branch.

[0071] The hydrogen produced by the PEM electrolysis branch and the ALK electrolysis branch is collected and enters the hydrogen storage unit 6, while the oxygen produced is collected and enters the electrolysis by-product oxygen buffer and supply unit 7.

[0072] Step 3: Green Methanol Synthesis and Storage

[0073] The methanol synthesis condensation and separation unit 9 receives hydrogen from the hydrogen storage unit 6 and carbon dioxide from the carbon dioxide buffer and supply unit 8, and reacts to produce methanol. The molar ratio of hydrogen to carbon dioxide is controlled at 2.8–3.2:1, the methanol synthesis reaction temperature is controlled at 220–280℃, and the reaction pressure is controlled at 5–10 MPa.

[0074] The generated methanol enters the methanol storage unit 10 after condensation and gas-liquid separation. Unreacted gases can be returned to the methanol synthesis process for continued use. The separated condensate enters the steam condensation and feedwater recovery unit 19, and after being treated by the water treatment unit 20, it is returned to the pure water storage and supply unit 5.

[0075] The methanol synthesis load is dynamically adjusted based on the hydrogen supply flow rate, carbon dioxide reserves, and methanol reserves. When the reserves of both the hydrogen storage unit 6 and the carbon dioxide buffer and supply unit 8 are higher than their respective preset values, and the methanol reserves of the methanol storage unit 10 are lower than a preset upper limit, the methanol synthesis load is started or increased. When either the hydrogen storage unit 6 or the carbon dioxide buffer and supply unit 8 fails to meet the preset conditions, the methanol synthesis load is reduced or stopped.

[0076] The green methanol in the methanol storage unit 10 has two utilization paths. The first is the external transportation path, where green methanol can be stored and transported externally as a liquid energy product, or used as a raw material for the preparation of downstream chemical products. The second is the internal auxiliary power supply path, where when the lithium battery energy storage unit 16 cannot meet the power gap compensation requirements, the methanol storage unit 10 supplies methanol to the methanol reforming and reforming gas conditioning unit 11 for auxiliary power generation.

[0077] Step 4: Auxiliary power generation from methanol reforming high-temperature proton exchange membrane fuel cell

[0078] When the output power of new energy is lower than the grid connection demand, and the lithium battery energy storage unit 16 cannot meet the power gap compensation demand on its own, the methanol in the methanol storage unit 10 and the water from the pure water storage and supply unit 5 or the condenser and feedwater recovery unit 19 enter the methanol reforming and reforming gas conditioning unit 11.

[0079] Methanol and water are mixed at a water-to-methanol molar ratio of 1.1–1.8:1 and then enter the evaporation zone, where the temperature is controlled at 120–180°C to form a mixed vapor. This vapor then enters the reforming reaction zone, where a reforming reaction occurs under the action of a methanol-water vapor reforming catalyst, producing hydrogen-rich reformed gas, mainly composed of hydrogen and carbon dioxide, with small amounts of carbon monoxide and unreacted water vapor. The temperature in the methanol reforming reaction zone is controlled at 220–280°C, and the reaction pressure is controlled at 0.1–0.5 MPa.

[0080] After condensation, gas-water separation, temperature regulation, pressure regulation, and carbon monoxide concentration regulation, the hydrogen-rich reformed gas meets the anode inlet requirements of the high-temperature proton exchange membrane fuel cell unit 12 and enters the anode of the high-temperature proton exchange membrane fuel cell unit 12. The operating temperature of the high-temperature proton exchange membrane fuel cell unit 12 is controlled between 150 and 200°C, and air is introduced into the cathode. The hydrogen-rich gas at the anode and the oxygen-containing gas at the cathode undergo an electrochemical reaction within the fuel cell stack to generate electricity. The electricity is then transmitted to the power grid 18 via the power conversion and boosting grid-connection unit 17.

[0081] The high-temperature proton exchange membrane fuel cell unit 12 can be modularly configured, with a rated power of 5 to 200 kW for a single module. When the auxiliary power demand is small, a single module is configured; when the power demand is high, multiple modules are connected in parallel to form an auxiliary power supply branch of 100 kW to 1 MW.

[0082] Step 5: Waste heat recovery from exhaust gas and catalytic combustion for heating

[0083] The cathode exhaust gas from the high-temperature proton exchange membrane fuel cell unit 12 enters the stack waste heat recovery unit 13. The cathode exhaust gas temperature is 150-190°C. The stack waste heat recovery unit 13 is equipped with a heat transfer medium heat exchange channel, and the heat transfer medium fully exchanges heat with the cathode exhaust gas, raising the temperature to 140-170°C.

[0084] The anode exhaust gas from the high-temperature proton exchange membrane fuel cell unit 12 enters the exhaust gas catalytic combustion and methanol afterburning heating unit 14. Unreacted hydrogen, carbon monoxide, and potentially combustible components such as methanol vapor in the anode exhaust gas undergo catalytic combustion with oxygen supplied by the electrolysis byproduct oxygen buffer and supply unit 7. The catalytic combustion bed temperature of the exhaust gas catalytic combustion and methanol afterburning heating unit 14 is controlled between 300 and 450°C.

[0085] When the calorific value of the anode tail gas is insufficient to meet the heat required for the methanol reforming reaction, the methanol storage unit 10 supplements methanol to the tail gas catalytic combustion and methanol afterburning heating unit 14 for afterburning. At this time, the heat transfer medium is heated a second time, and the temperature rises from 140-170℃ to 280-320℃.

[0086] The heat transfer medium then enters the methanol reforming and reforming gas conditioning unit 11 to heat the methanol evaporation zone and the reforming reaction zone, maintaining the methanol reforming reaction zone at a stable temperature of 220–280°C. After releasing heat, the temperature of the heat transfer medium drops to 120–140°C and returns to the fuel cell stack waste heat recovery unit 13 for continued circulation.

[0087] By adjusting the flow rate of the heat transfer medium, the supply of anode tail gas, the supply of electrolysis by-product oxygen, and the amount of methanol supplementary combustion, the temperature of the methanol reforming and reforming gas conditioning unit 11 is maintained within the set range.

[0088] Step Six: Carbohydrate Recycling

[0089] The exhaust gas discharged from the tail gas catalytic combustion and methanol afterburning heating unit 14 enters the tail gas condensation and CO2 capture and reuse unit 15. Water vapor in the tail gas is condensed and enters the steam condensation and feedwater recovery unit 19, then purified by the water treatment unit 20 before returning to the pure water storage and supply unit 5 for use in the mixed electrolytic water subsystem. Carbon dioxide in the tail gas is separated and compressed before returning to the carbon dioxide buffer and supply unit 8, serving as a raw material for the methanol synthesis condensation and separation unit 9 to continue participating in the methanol synthesis process.

[0090] The electrolysis by-product oxygen buffer and supply unit 7 receives oxygen generated by the PEM-ALK co-electrolysis hydrogen production unit 4 and cools, stabilizes, and buffers the oxygen. When the tail gas catalytic combustion and methanol afterburning heating unit 14 starts or the load increases, the electrolysis by-product oxygen buffer and supply unit 7 supplies oxygen to it to improve the stability of the anode tail gas catalytic combustion.

[0091] Through the above steps, the system forms a recycling path for carbon dioxide and water, as well as an internal utilization path for oxygen produced as a byproduct of electrolysis, in the processes of hydrogen production by electrolysis, methanol synthesis, methanol reforming, fuel cell auxiliary power generation, and exhaust gas treatment.

[0092] The following is a specific embodiment to further illustrate the technical solution and technical effects of the present invention.

[0093] A large energy base in a desert region is equipped with a photovoltaic power generation unit 1 with an installed capacity of 500 MW, a wind power generation unit 2 with an installed capacity of 300 MW, and a supporting lithium battery energy storage unit 16 with a rated power of 80 MW (accounting for 10% of the new energy installed capacity), an energy storage duration of 3 hours, a total capacity of 240 MWh, and a state-of-charge (SOC) operating range controlled between 20% and 90%. A PEM-ALK co-electrolysis hydrogen production unit 4 is configured with a PEM electrolysis branch with a rated power of 30 MW and an ALK electrolysis branch with a rated power of 60 MW. A methanol synthesis, condensation, and separation unit 9 is designed to produce 100 tons of methanol per day. A high-temperature proton exchange membrane fuel cell unit 12 is configured with 4 parallel modules, each with a rated power of 200 kW, and a total auxiliary power supply of 800 kW.

[0094] Example 1: Surplus Energy Operating Condition

[0095] From 10:00 to 14:00 on a certain day, the total output power of photovoltaic power generation unit 1 and wind power generation unit 2 is 680 MW, the grid connection demand is 600 MW, and there is a surplus of 80 MW of power.

[0096] The new energy power collection, regulation, and distribution unit 3 first sends 600 MW of new energy power into the grid 18 via the power conversion and step-up grid connection unit 17. The remaining 80 MW of surplus power is preferentially allocated to the lithium battery energy storage unit 16 for charging. The lithium battery energy storage unit 16 initially has a state of charge of 30%, and is charged at a power of 80 MW for 1.5 hours, after which 120 MWh is charged, and the state of charge rises to 80%, close to the set upper limit of 90%. At this time, the new energy power collection, regulation, and distribution unit 3 allocates the remaining surplus power to the PEM-ALK co-electrolysis hydrogen production unit 4.

[0097] Since the surplus power was relatively stable during this period, the ALK electrolysis branch operated stably at 60 MW, and the PEM electrolysis branch absorbed the fluctuation increment at 20 MW, absorbing a total of 80 MW of surplus power. The unit hydrogen production power consumption of PEM-ALK co-electrolysis hydrogen production unit 4 was controlled at 55 kWh / kg H2, and the cumulative hydrogen production during this period was approximately 2.2 t. The hydrogen entered the hydrogen storage unit 6, and the oxygen entered the electrolysis by-product oxygen buffer and supply unit 7.

[0098] Hydrogen storage unit 6 reaches a hydrogen storage capacity above the preset lower limit, carbon dioxide buffer and supply unit 8 has sufficient storage capacity, methanol storage unit 10 has a methanol storage capacity below the upper limit, and methanol synthesis condensation and separation unit 9 starts synthesis. Hydrogen and carbon dioxide enter the synthesis tower at a molar ratio of 3:1, with a reaction temperature of 250℃ and a reaction pressure of 8 MPa. During this period, approximately 10 tons of methanol are synthesized. The separated condensate is returned to pure water storage and supply unit 5 via condensate and feedwater recovery unit 19 and water treatment unit 20.

[0099] Example 2: Working Condition with Insufficient New Energy Sources

[0100] From 18:00 to 22:00 on the same day, the output power of photovoltaic power generation unit 1 dropped to 30 MW, the output power of wind power generation unit 2 was 100 MW, the total output power was 130 MW, the grid connection demand was 210.8 MW, and there was a power gap of 80.8 MW.

[0101] The new energy power collection, regulation, and distribution unit 3 transmits 130 MW of new energy power to the grid 18 via the power conversion and step-up grid connection unit 17. The lithium battery energy storage unit 16 is prioritized for activation, discharging at its rated power of 80 MW to compensate for the power shortfall. The lithium battery energy storage unit 16 initially has a state of charge of 90%. After discharging continuously at 80 MW power for 2 hours, it has discharged a cumulative 160 MWh, reducing its state of charge to approximately 23%, close to the set lower limit of 20%, and the discharge duration has reached the set threshold.

[0102] At this point, a power deficit of 800 kW (80.8 MW - 80 MW) still exists. The lithium-ion battery energy storage unit 16, due to insufficient state of charge and having reached its discharge power limit, cannot independently meet the power deficit compensation requirements. The new energy power collection, regulation, and distribution unit 3 starts the methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation system. The methanol storage unit 10 supplies methanol to the methanol reforming and reformed gas conditioning unit 11 at a flow rate of 280 kg / h, mixing it with water supplied by the pure water storage and supply unit 5 at a water-to-methanol molar ratio of 1.5:1. The evaporation zone temperature is 150℃, the reforming reaction zone temperature is 260℃, and the reaction pressure is 0.3 MPa, generating hydrogen-rich reformed gas. After condensation, vapor-water separation, temperature regulation, pressure regulation, and carbon monoxide concentration regulation, the reformed gas enters the high-temperature proton exchange membrane fuel cell unit 12.

[0103] The high-temperature proton exchange membrane fuel cell unit 12 operates at 180℃. With all four modules activated, it outputs 800 kW of electrical power, which is then fed into the power grid 18 via the power conversion and boost grid connection unit 17. At this time, the lithium battery energy storage unit 16 continues to discharge with its remaining available power, working together with the fuel cell to compensate for the power shortfall and ensure the stability of the power grid supply.

[0104] The cathode exhaust gas temperature of the high-temperature proton exchange membrane fuel cell unit 12 is approximately 170°C. It enters the stack waste heat recovery unit 13 and exchanges heat with the heat transfer medium, raising the medium temperature to 160°C. The anode exhaust gas enters the exhaust gas catalytic combustion and methanol afterburning heating unit 14, where it undergoes catalytic combustion with oxygen supplied by the electrolysis byproduct oxygen buffer and supply unit 7, reaching a bed temperature of 400°C. Any shortfall in the anode exhaust gas calorific value is supplemented by methanol afterburning in the methanol storage unit 10. The heat transfer medium is then reheated to 300°C and enters the methanol reforming and reformate gas conditioning unit 11 to heat the reforming reaction. After releasing heat, the temperature drops to 130°C and returns to the stack waste heat recovery unit 13.

[0105] The exhaust gas discharged from the tail gas catalytic combustion and methanol afterburning heating unit 14 enters the tail gas condensation and CO2 capture and reuse unit 15. After water vapor is condensed, it enters the steam condensation and feedwater recovery unit 19, and then returns to the pure water storage and supply unit 5 through the water treatment unit 20. After carbon dioxide is captured and compressed, it returns to the carbon dioxide buffer and supply unit 8 for methanol synthesis.

[0106] The electrolysis by-product oxygen buffer and supply unit 7 receives oxygen generated by the PEM-ALK co-electrolysis hydrogen production unit 4 and cools, stabilizes, and buffers the oxygen. When the tail gas catalytic combustion and methanol afterburning heating unit 14 starts or the load increases, the electrolysis by-product oxygen buffer and supply unit 7 supplies oxygen to it to improve the stability of the anode tail gas catalytic combustion.

[0107] As can be seen from the above embodiments, the present invention achieves the following technical effects:

[0108] During periods of surplus renewable energy, the system prioritizes the absorption of short-term surplus power through the lithium battery energy storage unit 16, and converts the continuous surplus power into green methanol chemical energy through the PEM-ALK co-electrolysis hydrogen production unit 4 and the green methanol synthesis and energy storage subsystem, thus avoiding wind and solar curtailment and improving the renewable energy consumption rate.

[0109] During periods of insufficient renewable energy, the system ensures grid stability through the coordinated operation of the lithium battery energy storage unit 16 for primary peak shaving and the high-temperature proton exchange membrane fuel cell unit 12 for auxiliary power supply. The lithium battery handles 80 MW of the 80.8 MW power shortfall for primary peak shaving, while the high-temperature proton exchange membrane fuel cell unit 12 handles the remaining 800 kW for auxiliary power supply, fully demonstrating the scheduling principle of primary peak shaving by lithium battery energy storage and auxiliary power supply by the methanol reforming high-temperature proton exchange membrane fuel cell. Simultaneously, through the exhaust gas waste heat recovery and catalytic combustion heating subsystem, the waste heat from the fuel cell stack and the chemical energy of the exhaust gas are coupled and utilized to provide a heat source for methanol reforming, improving the system's energy utilization efficiency. Through the carbon and water recovery and recycling subsystem, carbon dioxide and water are recycled, reducing system operating costs and carbon emissions.

[0110] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for operating a large-scale new energy base system integrating wind, solar, hydrogen, and alcohol, characterized in that, include: Based on the real-time output power of new energy sources, the grid connection demand power, the state of charge of lithium battery energy storage units, and the system power gap, renewable energy power is collected, regulated, and distributed. Hydrogen and oxygen are produced by using surplus renewable energy power through a PEM-ALK co-electrolysis hydrogen production unit. The hydrogen is then sent to a hydrogen storage unit and the oxygen is sent to an electrolysis by-product oxygen buffer and supply unit. The hydrogen in the hydrogen storage unit reacts with the carbon dioxide buffer and the carbon dioxide supplied by the supply unit to synthesize methanol, and the methanol is stored in the methanol storage unit. When the output power of new energy is lower than the grid connection demand and the lithium battery energy storage unit cannot meet the power gap compensation demand on its own, the methanol in the methanol storage unit is sent to the high-temperature proton exchange membrane fuel cell unit for power generation after methanol reforming and reforming gas conditioning, and then sent to the grid through the power conversion and boost grid connection unit. The cathode exhaust gas discharged from the high-temperature proton exchange membrane fuel cell unit is heat-exchanged with the heat transfer medium through the stack waste heat recovery unit. The anode exhaust gas and the oxygen provided by the electrolysis by-product oxygen buffer and supply unit are catalytically combusted in the exhaust gas catalytic combustion and methanol supplementary combustion heating unit, and the heat transfer medium is used to heat the methanol reforming reaction. The carbon dioxide in the exhaust gas discharged from the exhaust gas catalytic combustion and methanol supplementary combustion heating unit is captured and returned to the carbon dioxide buffer and supply unit, and the condensate is returned to the pure water storage and supply unit.

2. The operation method of the new energy base system integrating wind, solar, hydrogen, and alcohol as described in claim 1, characterized in that, The collection, regulation, and distribution are scheduled according to the principle of primary peak regulation by lithium battery energy storage and auxiliary power replenishment by methanol reforming high-temperature proton exchange membrane fuel cells: When the output power of new energy power generation meets the grid connection requirements, new energy power should be connected to the grid first through power conversion and step-up grid connection units; When the output power of new energy power generation exceeds the grid connection demand, the surplus power is preferentially allocated to the lithium battery energy storage unit for charging; when the lithium battery energy storage unit reaches the charging power limit, the state of charge reaches the set limit, or the surplus power duration exceeds the set threshold, the remaining surplus power is allocated to the PEM-ALK co-electrolysis hydrogen production unit. When the output power of new energy power generation is lower than the grid connection demand, the power gap is compensated by the discharge of lithium battery energy storage units. When the lithium battery energy storage unit cannot meet the power deficit compensation requirement on its own, the high-temperature proton exchange membrane fuel cell unit is activated to provide auxiliary power.

3. The operation method of the new energy base system integrating wind, solar, hydrogen, and alcohol as described in claim 1, characterized in that, The PEM-ALK co-electrolysis hydrogen production unit includes a PEM electrolysis branch and an ALK electrolysis branch, which are allocated to the corresponding branches according to the characteristics of surplus electricity: If the surplus power is a short-term fluctuating surplus power, it will be allocated to the PEM electrolysis branch. If the surplus power is a continuous surplus power, it is allocated to the ALK electrolysis branch. When surplus power includes both a stable base load portion and a fluctuating increment portion, the stable base load portion is allocated to the ALK electrolysis branch, and the fluctuating increment portion is allocated to the PEM electrolysis branch.

4. The operation method of the new energy base system integrating wind, solar, hydrogen, and alcohol as described in claim 1, characterized in that, Methanol synthesis load is dynamically adjusted based on hydrogen supply flow rate, carbon dioxide reserves, and methanol reserves. When the storage capacity of the hydrogen storage unit and the carbon dioxide buffer and supply unit are both higher than the corresponding preset values ​​and the methanol storage capacity of the methanol storage unit is lower than the preset upper limit, the methanol synthesis load is started or increased. If any of the hydrogen storage unit or the carbon dioxide buffer and supply unit fails to meet the preset conditions, the methanol synthesis load will be reduced or stopped.

5. The operation method of the new energy base system integrating wind, solar, hydrogen, and alcohol as described in claim 1, characterized in that, The heat transfer medium circulates between the fuel cell waste heat recovery unit, the tail gas catalytic combustion and methanol afterburning heating unit, and the methanol reforming and reformed gas conditioning unit, sequentially absorbing the heat released from the cathode tail gas waste heat, catalytic combustion and methanol afterburning, and releasing heat to the methanol reforming reaction.

6. The operation method of the new energy base system integrating wind, solar, hydrogen, and alcohol as described in claim 1, characterized in that, Through the exhaust gas condensation and CO2 capture and reuse unit, water treatment unit, pure water storage and supply unit, and electrolysis by-product oxygen buffer and supply unit, a carbon dioxide and water recycling path and an internal utilization path for electrolysis by-product oxygen are formed.

7. The operation method of the new energy base system integrating wind, solar, hydrogen, and alcohol as described in claim 1, characterized in that, The methanol reforming and reformed gas conditioning unit performs steam reforming of methanol to generate hydrogen-containing reformed gas, and then condenses, separates steam and water, regulates temperature, pressure and carbon monoxide concentration of the hydrogen-containing reformed gas to meet the anode inlet requirements of the high-temperature proton exchange membrane fuel cell unit.

8. The operation method of the new energy base system integrating wind, solar, hydrogen, and alcohol as described in claim 1, characterized in that, When the calorific value of the anode tail gas is insufficient to meet the heating demand of methanol reforming, methanol is supplemented from the methanol storage unit to the tail gas catalytic combustion and methanol supplementary combustion heating unit for supplementary combustion.

9. A new energy base system integrating wind, solar, hydrogen, and alcohol, characterized in that, include: The new energy power generation and power regulation subsystem includes a photovoltaic power generation unit, a wind power generation unit, and a new energy power collection, regulation and distribution unit. Both the photovoltaic power generation unit and the wind power generation unit are connected to the new energy power collection, regulation and distribution unit. The lithium battery energy storage main peak-shaving subsystem includes a lithium battery energy storage unit, which is connected to a new energy power collection, regulation and distribution unit and a power conversion and boost grid connection unit. The hybrid water electrolysis subsystem includes a pure water storage and supply unit, a PEM-ALK synergistic electrolysis hydrogen production unit, and an electrolysis by-product oxygen buffer and supply unit. The PEM-ALK synergistic electrolysis hydrogen production unit is connected to the new energy power collection, regulation and distribution unit and the pure water storage and supply unit, respectively. The electrolysis by-product oxygen buffer and supply unit is connected to the PEM-ALK synergistic electrolysis hydrogen production unit. The green methanol synthesis and energy storage subsystem includes a hydrogen storage unit, a carbon dioxide buffer and supply unit, a methanol synthesis condensation and separation unit, and a methanol storage unit. The hydrogen storage unit is connected to the PEM-ALK co-electrolysis hydrogen production unit. The methanol synthesis condensation and separation unit is connected to the hydrogen storage unit and the carbon dioxide buffer and supply unit, respectively. The methanol storage unit is connected to the methanol synthesis condensation and separation unit. A methanol reforming high-temperature proton exchange membrane fuel cell auxiliary power generation system includes a methanol reforming and reforming gas conditioning unit and a high-temperature proton exchange membrane fuel cell unit. The methanol reforming and reforming gas conditioning unit is connected to a methanol storage unit, a pure water storage and supply unit and the high-temperature proton exchange membrane fuel cell unit, respectively. The exhaust gas waste heat recovery and catalytic combustion heating subsystem includes a fuel cell stack waste heat recovery unit, an exhaust gas catalytic combustion and methanol afterburning heating unit, and a heat transfer medium circulation pipeline. The fuel cell stack waste heat recovery unit is connected to the cathode exhaust gas outlet of the high-temperature proton exchange membrane fuel cell unit. The exhaust gas catalytic combustion and methanol afterburning heating unit is connected to the anode exhaust gas outlet, the electrolysis by-product oxygen buffer and supply unit, and the methanol storage unit of the high-temperature proton exchange membrane fuel cell unit, respectively. The heat transfer medium circulation pipeline is connected to the fuel cell stack waste heat recovery unit, the exhaust gas catalytic combustion and methanol afterburning heating unit, and the methanol reforming and reformed gas conditioning unit. The carbon and water recovery cycle subsystem includes a tail gas condensation and CO2 capture and reuse unit, a steam condensation and feedwater recovery unit, a water treatment unit, and a carbon dioxide buffer and supply unit. The tail gas condensation and CO2 capture and reuse unit is connected to the tail gas catalytic combustion and methanol supplementary combustion heating unit and the carbon dioxide buffer and supply unit, respectively. The water outlet of the tail gas condensation and CO2 capture and reuse unit is connected to the pure water storage and supply unit through the steam condensation and feedwater recovery unit and the water treatment unit. The power conversion and grid-connected booster unit is connected to the new energy power collection, regulation and distribution unit, the lithium battery energy storage unit and the high-temperature proton exchange membrane fuel cell unit, respectively.

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