Comprehensive energy system utilizing LNG (liquefied natural gas) multi-energy complementary comprehensive output

Abstract

The invention relates to the technical field of comprehensive energy utilization, and provides a comprehensive energy system utilizing LNG (Liquefied Natural Gas) multi-energy complementary comprehensive output, which comprises an LNG cold energy utilization system, a methane cracking hydrogen production system, a power generation and power supply system, a waste heat centralized utilization system and a product supply system. A natural gas direct cracking hydrogen production technology, an LNG (Liquefied Natural Gas) cold energy utilization technology and a waste heat utilization technology are mainly utilized to realize natural gas state conversion, hydrogen production and hydrogen pre-cooling, and liquid hydrogen is prepared by utilizing a multi-stage circulating hydrogen cooling technology; meanwhile, by-product carbon of the methane cracking hydrogen production technology can be used as a high-purity carbon raw material after being captured and processed, and is used for processing various by-products. The system has the advantages of comprehensive energy resource output, extremely low carbon comprehensive emission and pollutant emission, cold and hot energy comprehensive regulation and control, energy safety guarantee and the like, and zero-carbon liquid hydrogen can be provided in a more energy-saving and environment-friendly manner.

Description

Technical Field

[0001] The present invention relates to the technical field of comprehensive energy utilization. Specifically, it relates to a comprehensive energy system that comprehensively outputs energy through the complementary use of multiple energies of LNG. Background Art

[0002] LNG has high-grade and abundant cold energy. Its utilization is an environmental protection behavior of "turning waste into treasure" through resource recycling. The main difficulty in cold energy utilization projects is how to scientifically overallocate cold energy resources and cold energy demands. Natural gas reforming is one of the main hydrogen production methods in China. The traditional steam reforming technology for natural gas reforming has a mature process flow, high efficiency, and low cost, but has high carbon emissions and is difficult to carry out carbon capture; electrolytic water hydrogen production has the characteristics of high purity, no pollution, and zero carbon emissions, but the hydrogen production cost is too high. The methane direct cracking hydrogen production method with the support of high-efficiency catalysts combines the above advantages and is a more advanced hydrogen production method.

[0003] After retrieval, the invention with the publication number (CN113113922A) discloses a comprehensive energy supply system, including: a substation, a hydrogen production module, LNG cold energy utilization, an auxiliary system module, and a comprehensive energy supply module. The hydrogen production module is used to produce hydrogen energy by electrolyzing water and generate electricity through a fuel cell module; LNG cold energy utilization is used to store electric energy and hydrogen energy and convert hydrogen energy into electric energy and heat energy with the assistance of the fuel cell module; the fuel cell module is used to convert hydrogen energy into electric energy and heat energy with the assistance of the auxiliary system module; the comprehensive energy supply module is used to provide charging supply services, hydrogen refueling supply services, and heating services.

[0004] In the above solution, the comprehensive energy system is based on electric energy, the utilization of energy is not thorough, and the internal energy cycle consumption is large. It cannot independently output energy to the outside, relies on external electric energy, and its energy cycle is not environmentally friendly enough, and the energy consumption of the energy station itself is too large.

[0005] In view of this, the present invention proposes a comprehensive energy system that comprehensively outputs energy through the complementary use of multiple energies of LNG. Summary of the Invention

[0006] The present invention proposes a comprehensive energy system that comprehensively outputs energy through the complementary use of multiple energies of LNG, solving the problems of large energy cycle consumption, incomplete energy utilization, and insufficient environmental friendliness in the related technologies.

[0007] The technical solution of the present invention is as follows: A comprehensive energy system that comprehensively outputs energy through the complementary use of multiple energies of LNG, including: an LNG cold energy utilization system, a methane cracking hydrogen production system, a power generation and power supply system, a waste heat centralized utilization system, and a product supply system;

[0008] The LNG cold energy utilization system includes a hydrogen precooling device, and the hydrogen precooling device includes a hydrogen cooling heat exchanger and an ortho-para hydrogen converter;

[0009] The methane cracking hydrogen production system includes a cracking hydrogen production reaction device and a PSA hydrogen purification device, and the cracking hydrogen production reaction device is connected to an external power grid;

[0010] The power generation and power supply system includes a SOFC fuel cell power generation device, a DC-AC inverter device, and a power transmission device adapted to the SOFC fuel cell power generation device and the DC-AC inverter device. The cracking hydrogen production reaction device is also electrically connected to the DC-AC inverter device;

[0011] The waste heat centralized utilization system includes a water bath heater and a waste heat heat exchanger, and jointly supplies heat to the water bath heater through the waste heat heat exchanger;

[0012] The product supply system includes a pure carbon processing module, a liquid hydrogen production module, a standard hydrogen processing module, a natural gas production module, and an energy storage module;

[0013] The waste heat heat exchanger is coupled with an ammonia-water absorption refrigeration unit, and through cascade conversion of the waste heat discharged from the SOFC at 200-300 °C, a low-temperature refrigerant at -20 °C is generated and jointly distributed to:

[0014] (a) A gaseous impurity condensation and removal unit at the front end of LNG gasification;

[0015] (b) An inert environment temperature control bin for solid carbon products;

[0016] To achieve the closed-loop operation of waste heat resource utilization, cold energy cascade utilization, purification, and anti-oxidation;

[0017] An intelligent gas distribution valve group is arranged between the PSA hydrogen purification device and the SOFC power generation system. Based on real-time electricity price signals and a hydrogen demand prediction model, the tail gas is dynamically distributed to peak electricity price periods, valley periods, and emergency conditions.

[0018] Preferably, the hydrogen precooling device is connected to an external LNG storage device, and the low-temperature liquefied natural gas provided by the LNG storage device to the hydrogen precooling device is used to provide cold energy to the hydrogen precooling device. The low-temperature hydrogen precooled by the hydrogen precooling device is connected to a J-T cycle liquefaction system and further cooled and liquefied through the J-T cycle liquefaction system.

[0019] Preferably, for the mixed gas produced during the operation of the cracking hydrogen production reaction device, the mixed gas includes methane and hydrogen, which is received by the PSA hydrogen purification device, and the high-purity hydrogen produced by the PSA hydrogen purification device is input into a gaseous hydrogen storage tank.

[0020] Preferably, the SOFC fuel cell power generation device is electrically connected to the PSA hydrogen purification device, and the PSA hydrogen purification device generates electricity using the exhaust gas rich in methane and hydrogen produced by the PSA hydrogen purification device.

[0021] Preferably, the SOFC fuel cell power generation device is also electrically connected to the waste heat centralized utilization system, and a large amount of heat generated during the operation of the SOFC fuel cell power generation device is centrally heat exchanged in the waste heat centralized utilization system.

[0022] Preferably, the power transmission device is electrically connected to the DC-AC inverter device, and the DC-AC inverter device is electrically connected to the cracking hydrogen production reaction device, the J-T cycle cooling system, and the energy storage module.

[0023] Preferably, the waste heat exchanger collects the waste heat generated by the centralized SOFC fuel cell power generation device and the cracking hydrogen production reaction device, and is used for combined heat supply to the water bath heater.

[0024] Preferably, the natural gas output module is connected to the water bath heater, and is used to transport the LNG after the cold energy utilization is completed and the methane gas remaining in the station to the gas filling station.

[0025] Preferably, the liquid hydrogen output module includes a liquid hydrogen storage tank, and the liquid hydrogen storage tank is connected to the J-T cycle liquefaction system, and is used to store the produced liquid hydrogen and supply the stored liquid hydrogen to the liquid hydrogen supply station through a pipeline.

[0026] The working principle and beneficial effects of the present invention are as follows:

[0027] 1. The present invention has a wide application space in the field of urban comprehensive energy stations, and conforms to the future development direction of low-carbon environmental protection and hydrogen energy dominance. It provides a comprehensive energy station for hydrogen production and storage, mainly using natural gas direct cracking hydrogen production technology, LNG cold energy utilization technology, and waste heat utilization technology to realize the transformation of natural gas state, hydrogen production, hydrogen precooling, and the production of liquid hydrogen using multi-stage cycle hydrogen cooling technology; at the same time, the by-product carbon of the methane cracking hydrogen production technology can be captured and processed, and can be used as a high-purity carbon raw material for processing various by-products. It has the advantages of outputting comprehensive energy resources, extremely low carbon and pollutant emissions, comprehensive regulation of cold and heat energy, and energy security guarantee, and can provide zero-carbon liquid hydrogen more energy-efficiently and environmentally friendly;

[0028] 2. In the present invention, from the perspective of hydrogen refueling, storage, and transportation, liquid hydrogen has high purity and high hydrogenation efficiency, making it suitable for large-scale storage and transportation with significant scale benefits. At the same time, compared with other hydrogen production technologies, the methane direct cracking hydrogen production technology has the following advantages: 1) single-step reaction, simple principle, and reliable reaction; 2) high value of by-product carbon, which can be output as raw materials for various industrial products. Also, compared with the traditional methane catalytic reforming hydrogen production method, the form of by-product carbon is not carbon dioxide, making it easier for carbon precipitation and capture; 3) high H2 content in the outlet gas, which is easy to separate. Using LNG for hydrogen precooling saves energy and has high efficiency; methane direct cracking hydrogen production has no carbon emissions and high by-product value. With sufficient liquefied natural gas provided, the present invention can produce liquid hydrogen, natural gas, and standard gaseous hydrogen under the requirement of zero carbon emissions, and comprehensively utilize cold and heat energy in the energy station, which is an independent and efficient integrated energy system. Among them, liquid hydrogen can be used as fuel for aerospace or new energy vehicles; by-product carbon can be used as high-precision industrial raw materials, natural gas will be comprehensively utilized for its original purposes, and the produced standard gaseous hydrogen can be connected to a gas filling station to provide fuel supply for fuel cell passenger vehicles. The present invention can be used in urban integrated energy stations to achieve the goal of providing comprehensive energy supply in an energy-saving and environmentally friendly manner;

[0029] 3. In the present invention, the waste heat heat exchanger is coupled with an ammonia-water absorption refrigeration unit to generate -20°C low-temperature refrigerant through cascade conversion of the 200 - 300°C waste heat discharged from the SOFC and synergistically distribute it to the gaseous impurity condensation and removal unit at the front end of LNG gasification and the inert environment temperature control bin for solid carbon products, so as to achieve the closed-loop operation of waste heat resource utilization, cold energy cascade utilization, and purification and anti-oxidation; an intelligent gas distribution valve group is set between the PSA hydrogen purification device and the SOFC power generation system. Based on real-time electricity price signals and hydrogen demand prediction models, the tail gas is dynamically distributed as follows: during peak electricity price periods: preferentially transported to the SOFC for power generation and energy storage; during low valley periods: reinjected into the cracking reactor as a carrier gas to increase the hydrogen production rate; in emergency conditions: directly supplied to the buffer tank of the hydrogen filling station. To maximize energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0031] Figure 1 It is a schematic structural diagram of the integrated energy system proposed by the present invention;

[0032] Figure 2 It is a schematic diagram of the main working components of the integrated energy system proposed by the present invention;

[0033] Figure 3 It is a schematic diagram of the working mode of the urban integrated energy station system proposed by the present invention;

[0034] Figure 4Schematic structural diagram of a hydrogen cryogenic multi-stage J-T cycle system proposed by the present invention;

[0035] Figure 5 Intelligent allocation logic diagram of multi-path tail gas proposed by the present invention;

[0036] In the figure: 1. LNG cold energy utilization system; 101. Hydrogen pre-cooling device; 2. Methane cracking hydrogen production system; 201. Cracking hydrogen production reaction device; 202. PSA hydrogen purification device; 3. Power generation and power supply system; 301. SOFC fuel cell power generation device; 302. DC-AC inverter device; 4. Waste heat centralized utilization system; 401. Water bath heater; 402. Waste heat heat exchanger; 5. Product supply system; 501. Pure carbon processing module; 502. Liquid hydrogen production module; 503. Standard hydrogen processing module; 504. Natural gas production module; 505. Energy storage module. Detailed implementation manners

[0037] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of description, only parts related to the present invention rather than all structures are shown in the drawings.

[0038] It should be noted that the following various embodiments of the present invention can be executed independently, and the various embodiments can also be combined with each other. The embodiments of the present invention do not make specific restrictions on this. The "and / or" mentioned in the embodiments of the present invention refers to any and all combinations including one or more of the related listed items. In the embodiments of the present invention, "first", "second", "third", etc. are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another. And, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are also intended to include the plural forms.

[0039] Please refer to Figures 1-4, an embodiment of the present application discloses an integrated energy system using LNG multi-energy complementary comprehensive output, including: an LNG cold energy utilization system 1, a methane cracking hydrogen production system 2, a power generation and power supply system 3, a waste heat centralized utilization system 4, and a product supply system 5. Among them, the LNG cold energy utilization system 1 includes a hydrogen pre-cooling device 101, and the hydrogen pre-cooling device 101 includes a hydrogen cooling heat exchanger and an ortho-para hydrogen converter. The methane cracking hydrogen production system 2 includes a cracking hydrogen production reaction device 201 and a PSA hydrogen purification device 202, and the cracking hydrogen production reaction device 201 is connected to an external power grid. The power generation and power supply system 3 includes an SOFC fuel cell power generation device 301, a DC-AC inverter device 302, and a power transmission device adapted to the SOFC fuel cell power generation device 301 and the DC-AC inverter device 302. The cracking hydrogen production reaction device 201 is also electrically connected to the DC-AC inverter device 302. In case of an emergency, the power supply system can serve as a safe emergency guarantee to support the security of energy supply. The waste heat centralized utilization system 4 includes a water bath heater 401 and a waste heat heat exchanger 402, and jointly supplies heat to the water bath heater 401 through the waste heat heat exchanger 402. The product supply system 5 includes a pure carbon processing module 501, a liquid hydrogen production module 502, a standard hydrogen processing module 503, a natural gas production module 504, and an energy storage module 505. The hydrogen pre-cooling device 101 is connected to an external LNG storage device, and low-temperature liquefied natural gas provided by the LNG storage device is supplied to the hydrogen pre-cooling device 101, and then cold energy is supplied to the hydrogen pre-cooling device 101. The low-temperature hydrogen pre-cooled by the hydrogen pre-cooling device 101 is connected to a J-T cycle liquefaction system and further cooled and liquefied through the J-T cycle liquefaction system.

[0040] The waste heat heat exchanger 402 is coupled with an ammonia-water absorption refrigeration unit, and through cascade conversion of the waste heat discharged from the SOFC at 200-300 °C, a -20 °C low-temperature refrigerant is generated and jointly distributed to:

[0041] (a) The gaseous impurity condensation and removal unit at the front end of LNG gasification;

[0042] (b) The inert environment temperature control bin for solid carbon products;

[0043] To achieve the closed-loop operation of waste heat resource utilization, cold energy cascade utilization, and purification and anti-oxidation;

[0044] Specifically, collect the waste heat discharged from the SOFC at 200-300 °C as the driving heat source, and realize the conversion of thermal energy through the thermodynamic cycle of the ammonia water solution (generator → condenser → evaporator → absorber); adopt a two-stage step-down design. The first stage reduces the waste heat to 80-100 °C for heating the circulating water at the front end of LNG gasification, and the second stage generates a -20 °C low-temperature refrigerant through the ammonia evaporation endothermic effect.

[0045] LNG Gasification Front-end Purification Unit: Introduce -20°C refrigerant into the gaseous impurity condenser to condense and separate impurities such as ethane and hydrogen sulfide at low temperature, improving the purity of natural gas;

[0046] Solid Carbon Temperature Control Bin: Maintain an inert environment (-15 to -10°C, nitrogen atmosphere) in the bin through a coiled refrigerant distributor to inhibit the oxidation reaction of carbon products and control the agglomeration rate of carbon black particles.

[0047] An intelligent gas distribution valve group is set between the PSA hydrogen purification device 202 and the SOFC power generation system 301. Based on real-time electricity price signals and hydrogen demand prediction models, the tail gas is dynamically distributed to:

[0048] Peak electricity price period: Priority is given to transporting it to the SOFC for power generation and energy storage;

[0049] Valley period: Re-inject it into the cracking reactor as a carrier gas to increase the hydrogen production rate;

[0050] Emergency condition: Directly supply the hydrogenation station buffer tank. Maximize the energy utilization rate.

[0051] Specifically, an intelligent gas distribution valve group is provided between the PSA hydrogen purification device (202) and the SOFC power generation system, and its operation logic is as follows:

[0052] (I) Data acquisition stage:

[0053] · Obtain real-time grid electricity price signals (such as accessing the power dispatching system through the Modbus RTU protocol);

[0054] · Monitor the liquid level of the hydrogenation station buffer tank (using an ultrasonic liquid level sensor with an accuracy of ±1%);

[0055] · Update the hydrogen demand prediction value every 15 minutes (based on historical hydrogenation data).

[0056] (II) Dynamic distribution strategy (as shown below)

[0057]

[0058]

[0059] (III) Energy efficiency optimization mechanism

[0060] Peak period: Maximize the SOFC power generation revenue during the high-price electricity period;

[0061] Valley period: Re-inject methane in the tail gas to increase the cracking reaction rate;

[0062] Emergency mode: Ensure continuous hydrogen supply to the hydrogenation station.

[0063] Specifically, after heat exchange, the hydrogen gas is cooled to 120K - 140K by the heat exchange medium to complete the preliminary cooling. The cryogenic hydrogen gas to be liquefied is connected to the J-T cycle liquefaction system for further liquefaction into liquid hydrogen. Meanwhile, the methane gas after temperature rise is used as a raw material, supplied to the cracking hydrogen production reaction device 201, transported through the natural gas pipeline of the product supply system 5, and further supplied to a gas filling station or used for comprehensive utilization for its original purpose.

[0064] It should be noted that the J-T cycle liquefaction system is a commonly used system for the cryogenic liquefaction of hydrogen and belongs to the prior art. The patent invention publication number using this technology is attached here: CN115597308A.

[0065] In addition, the mixed gas produced during the operation of the cracking hydrogen production reaction device 201, which includes methane and hydrogen, is received by the PSA hydrogen purification device 202, and the high-purity hydrogen produced by the PSA hydrogen purification device 202 is input into the gaseous hydrogen storage tank. The cracking hydrogen production reaction device 201 is mainly connected to the power grid for power supply and is also connected to the DC-AC inverter device 302 for power supply in case of emergency. Specifically, in the application scenario, taking the example of an urban integrated energy station, since the urban electric energy resources are responsible, it is mainly connected to the power grid. However, if this system is used in areas with scarce power resources, it can also be connected to other power supply systems. Similarly, in the specific application of an urban integrated energy station, connecting the SOFC fuel cell power generation device 301 and the DC-AC inverter device 302 for power supply is only used as emergency power supply. If in other application scenarios, such as the Arctic scientific research station without power resources, etc., the SOFC power generation system can be used as the main power supply source.

[0066] Since the cracking hydrogen production reaction is a strongly exothermic reaction, the waste heat generated is transported to the waste heat centralized utilization system 4. The product gas of the cracking hydrogen production reaction is a hydrogen-methane mixture. The product gas enters the PSA hydrogen purification device 202, and the high-purity hydrogen produced is input into the gaseous hydrogen storage tank, and the remaining tail gas is repeatedly input into the purification device; or adjusted as needed and input to the SOFC fuel cell power generation device 301 for power generation and comprehensive regulation. The specific principle is to adjust the peak and valley of the power supply according to the power supply amount, consume the excess tail gas, and the SOFC fuel cell power generation device 301 consumes the excess tail gas and supplements power generation when the power supply is insufficient.

[0067] Meanwhile, the by-product carbon produced by the cracking hydrogen production reaction device 201 undergoes precipitation and filtration, enters the by-product carbon collection device, and is further processed and output as an industrial product. At the same time, the hydrogen gas produced by the PSA hydrogen purification device 202 can directly enter the standard hydrogen processing device in the standard hydrogen processing module 503, and after boosting and cooling, it enters the hydrogen filling station as 35MPa and 70MPa standard gaseous hydrogen to supply hydrogen to fuel cell vehicles, electric vehicles, etc.

[0068] In addition, for an integrated energy system that uses liquefied natural gas to produce and store hydrogen, the cryogenic part of hydrogen mainly utilizes the Joule-Thomson (J-T) principle and related devices. Most of the circulating working fluids commonly used for hydrogen precooling are liquid hydrogen or mixed coolants at present. Low-temperature liquid hydrogen (LN2) is usually used for precooling hydrogen in existing liquefaction processes. As Figure 4 shown, H1, H2, H3, H4 (LH2) represent the process of gradually heat-exchanging and cooling the precooled hydrogen to become liquid hydrogen, and MR1, MR2 represent the circulation of the circulating refrigerant liquid hydrogen in the cooling device, and through heat exchangers, expanders, compressors, and water coolers, the process of repeatedly cooling hydrogen by inputting energy is carried out.

[0069] The SOFC fuel cell power generation device 301 is electrically connected to the PSA hydrogen purification device 202, and the PSA hydrogen purification device 202 uses the tail gas rich in methane and hydrogen generated by the PSA hydrogen purification device 202 for power generation. At the same time, the SOFC fuel cell power generation device 301 is also electrically connected to the waste heat centralized utilization system 4, and a large amount of heat generated during the operation of the SOFC fuel cell power generation device 301 is centrally heat-exchanged in the waste heat centralized utilization system 4 and further utilized in the energy station. It can also be supplied to the in-station waste heat system to supply heat to the station. While regulating the heat energy, it can solve part of the in-station heat demand. The consumption of mismatched cold and heat energy by the system can be used as a supplement for cooling and heating supply in the downstream park, reducing part of the cost.

[0070] At the same time, the power transmission device is electrically connected to the DC-AC inverter device 302, and the DC-AC inverter device 302 is electrically connected to the cracking hydrogen production reaction device 201, the J-T cycle cooling system, and the energy storage module 505. It inversely converts the generated power into alternating current that can be used by other electrical appliances in the energy station for temporary emergency use, and is electrically connected to the cracking hydrogen production reaction device 201, the J-T cycle cooling system, and the energy storage module 505, facilitating the operation of each device during power outages and peak shaving periods, while consuming the tail gas of the PSA hydrogen purification device 202 and regulating the hydrogen production.

[0071] The waste heat exchanger 402 collects the waste heat generated by the SOFC fuel cell power generation device 301 and the cracking hydrogen production reaction device 201 and is used for combined heat supply to the water bath heater 401. The low-temperature methane after heat exchange in the cold energy utilization system enters the waste heat centralized utilization system 4, is heated to become usable methane gas, and is input into the cracking hydrogen production reaction device 201, part of it is input into the SOFC fuel cell power generation device 301, and the rest is all input into the gas filling station of the energy station and supplied outward from the gas filling station as natural gas output.

[0072] The natural gas output module 504 is connected to the water bath heater 401, and is used to transport the LNG after the cold energy utilization and the methane gas remaining in the station application to the gas filling station or other industrial enterprises for the original use of the methane gas. The liquid hydrogen output module 502 includes a liquid hydrogen storage tank, and the liquid hydrogen storage tank is connected to the J-T cycle liquefaction system, and is used to store the manufactured liquid hydrogen and supply the stored liquid hydrogen to the liquid hydrogen supply station through a pipeline, which is the main function of this energy station. At the same time, the standard hydrogen processing device can process the obtained high-purity hydrogen into 35MP or 70MPa hydrogen and send it to the hydrogen refueling station for refueling fuel cell vehicles, etc.; the hydrogen refueling station includes a control device and a conveying device, a hydrogen compression device, and a filling device connected in sequence, wherein the filling device can be used to fill hydrogen for various mobile fuel cell systems. At the same time, it can also be connected to a traditional gas filling station to provide fuel for various methane-driven internal combustion locomotives. The remaining energy in the energy station will be centrally stored and utilized, playing a certain role in peak shaving, valley filling, and storing emergency energy for safety.

[0073] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An integrated energy system using LNG multi-energy complementary comprehensive output, characterized in that, Comprising: LNG cold energy utilization system (1), methane cracking hydrogen production system (2), power generation and power supply system (3), waste heat centralized utilization system (4) and product supply system (5); The LNG cold energy utilization system (1) includes a hydrogen pre-cooling device (101), and the hydrogen pre-cooling device (101) includes a hydrogen cooling heat exchanger and an ortho-para hydrogen converter; The methane cracking hydrogen production system (2) includes a cracking hydrogen production reaction device (201) and a PSA hydrogen purification device (202), and the cracking hydrogen production reaction device (201) is connected to an external power grid; The power generation and power supply system (3) includes a SOFC fuel cell power generation device (301), a DC-AC inverter device (302) and a power transmission device adapted to the SOFC fuel cell power generation device (301) and the DC-AC inverter device (302), and the cracking hydrogen production reaction device (201) is also electrically connected to the DC-AC inverter device (302); The waste heat centralized utilization system (4) includes a water bath heater (401) and a waste heat heat exchanger (402), and jointly supplies heat to the water bath heater (401) through the waste heat heat exchanger (402); The product supply system (5) includes a pure carbon processing module (501), a liquid hydrogen production module (502), a standard hydrogen processing module (503), a natural gas production module (504) and an energy storage module (505); The waste heat heat exchanger (402) is coupled with an ammonia water absorption refrigeration unit, and through cascade conversion of the waste heat discharged from the SOFC at 200 - 300 °C, generates a -20 °C low-temperature refrigerant and cooperatively distributes it to: (a) A gaseous impurity condensation and removal unit at the front end of LNG gasification; (b) An inert environment temperature control bin for solid carbon products; To achieve a closed-loop operation of waste heat resource utilization, cold energy cascade utilization, purification and anti-oxidation; An intelligent gas distribution valve group is arranged between the PSA hydrogen purification device (202) and the SOFC power generation system (301), and based on real-time electricity price signals and a hydrogen demand prediction model, dynamically distributes the tail gas to peak electricity price periods, valley periods and emergency conditions.

2. The integrated energy system using LNG multi-energy complementary comprehensive output according to claim 1, wherein The hydrogen pre-cooling device (101) is connected to an external LNG storage device, and the low-temperature liquefied natural gas provided by the LNG storage device to the hydrogen pre-cooling device (101) is used to provide cold energy to the hydrogen pre-cooling device (101). The low-temperature hydrogen pre-cooled by the hydrogen pre-cooling device (101) is connected to a J-T cycle liquefaction system and is further cooled and liquefied through the J-T cycle liquefaction system.

3. A comprehensive energy system using LNG multi-energy complementary integrated output according to claim 1, characterized in that, The mixed gas produced during the operation of the cracking hydrogen production reaction device (201), the mixed gas includes methane and hydrogen, is received by the PSA hydrogen purification device (202), and the high-purity hydrogen produced by the PSA hydrogen purification device (202) is input into a gaseous hydrogen storage tank.

4. A comprehensive energy system using LNG multi-energy complementary integrated output according to claim 3, characterized in that, The SOFC fuel cell power generation device (301) is electrically connected to the PSA hydrogen purification device (202), and the PSA hydrogen purification device (try to avoid repeating the device name here, just use "it") uses the tail gas rich in methane and hydrogen generated by it for power generation.

5. The integrated energy system using LNG multi-energy complementary integrated output according to claim 4, characterized in that The SOFC fuel cell power generation device (301) is also electrically connected to the waste heat centralized utilization system (4), and a large amount of heat generated during the operation of the SOFC fuel cell power generation device (301) is centrally heat exchanged in the waste heat centralized utilization system (4).

6. The integrated energy system utilizing LNG multi-energy complementary integrated output according to claim 5, characterized in that, The power transmission device is electrically connected to the DC-AC inverter device (302), and the DC-AC inverter device (302) is electrically connected to the cracking hydrogen production reaction device (201), the J-T cycle cooling system, and the energy storage module (505).

7. The integrated energy system using LNG multi-energy complementary integrated output according to claim 6, characterized in that, The waste heat heat exchanger (402) is used for jointly heating the water bath heater (401) by concentrating the waste heat generated by the SOFC fuel cell power generation device (301) and the cracking hydrogen production reaction device (201).

8. A comprehensive energy system utilizing integrated output of LNG multi-energy complementarity according to claim 7, characterized in that, The natural gas output module (504) is connected to the water bath heater (401) and is used to transport the LNG after the cold energy utilization and the methane gas remaining in the station to the gas filling station.

9. The integrated energy system using LNG multi-energy complementary integrated output according to claim 1, wherein The liquid hydrogen output module (502) includes a liquid hydrogen storage tank. The liquid hydrogen storage tank is connected to the J-T cycle liquefaction system and is used to store the manufactured liquid hydrogen and supply the stored liquid hydrogen to the liquid hydrogen supply station through a pipeline.

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