Offshore energy processing system

Abstract

This invention relates to a marine energy processing system. Compared with existing technologies, this invention uses a power conversion unit to process external green energy into direct current (DC). A superconducting transmission bus transmits a portion of the DC power from the power conversion unit to onshore electrical equipment. Seawater is desalinated using a desalination device to obtain fresh water. A hydrogen production device uses a portion of the DC power from the power conversion unit to electrolyze the fresh water into hydrogen. A hydrogen compressor cools and compresses the hydrogen to obtain liquid hydrogen. A liquid hydrogen transport channel delivers the liquid hydrogen to onshore hydrogen equipment, achieving effective peak shaving and consumption. Simultaneously, the liquid hydrogen transport channel is located outside the superconducting transmission bus, allowing for cooling of the superconducting transmission bus and enabling the simultaneous transmission of chemical energy and DC power. This achieves diversified storage and consumption of electrical energy, reducing losses and costs during the energy consumption process and providing a feasible path for the efficient utilization of large-scale renewable energy.

Description

Technical Field

[0001] This invention relates to the field of marine energy processing technology, and in particular to a marine energy processing system. Background Technology

[0002] As offshore wind power, tidal energy, and photovoltaic projects develop towards large-scale and deep-sea deployments, the distance from shore to the sites has increased significantly, leading to a continuous rise in the cost of grid connection and consumption of electricity. Under current technological and economic conditions, except for specific scenarios such as supplying power to offshore oil and gas fields, deep-sea renewable energy projects generally lack engineering-feasible solutions for power transmission or local consumption.

[0003] Existing deep-sea green energy technologies generally lack economic viability. Constrained by the intermittency and volatility of wind, tidal, and photovoltaic resources, the power generation window exhibits significant temporal uncertainty, making it difficult to match output curves with grid load demand. Aside from configuring large-capacity batteries for time-shifted regulation, there is currently a lack of other effective peak-shaving and load-absorbing methods, resulting in persistently high curtailment rates and further exacerbating the levelized cost of electricity. Therefore, while deep-sea green energy is technically feasible, its lack of cost constraints limits its practical engineering application value. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a marine energy processing system.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A marine energy processing system provided by the present invention includes a power conversion unit, a superconducting power transmission bus, a hydrogen production device, a freshwater preparation device, a hydrogen compressor, and a liquid hydrogen transportation channel;

[0007] The power conversion unit processes external green energy and converts it into direct current (DC). The first output terminal of the power conversion unit is electrically connected to one end of a superconducting transmission bus, and the other end of the superconducting transmission bus is connected to onshore electrical equipment, so that the superconducting transmission bus can transmit the DC power output from the first output terminal to the onshore electrical equipment.

[0008] The freshwater preparation device desalinates seawater to obtain freshwater. The freshwater outlet of the freshwater preparation device is connected to the freshwater inlet of the hydrogen production device. The second output terminal of the power conversion unit is electrically connected to the hydrogen production device so that the hydrogen production device uses the direct current output from the second output terminal to convert the freshwater into hydrogen through electrolysis.

[0009] The first hydrogen outlet of the hydrogen production device is connected to the hydrogen compressor, which cools and compresses the hydrogen to obtain liquid hydrogen.

[0010] The liquid hydrogen outlet of the hydrogen compressor is connected to one end of the liquid hydrogen delivery channel, and the other end of the liquid hydrogen delivery channel is connected to the onshore hydrogen equipment.

[0011] The liquid hydrogen transport channel is installed around the superconducting power transmission bus as its inner axis.

[0012] Compared with existing technologies, this invention uses a power conversion unit to process external green energy into direct current (DC). A superconducting transmission bus transmits the DC power output from the first output of the power conversion unit to onshore equipment. Seawater is desalinated using a desalination device to obtain fresh water. A hydrogen production device uses the DC power output from the second output of the power conversion unit to electrolyze the fresh water into hydrogen. A hydrogen compressor cools and compresses the hydrogen to obtain liquid hydrogen. A liquid hydrogen transport channel delivers the liquid hydrogen to onshore hydrogen production equipment. This invention is no longer constrained by the intermittency and volatility of wind, tidal, and photovoltaic resources, achieving a more efficient matching of energy sources. By aligning the power curve with grid load demand, effective peak shaving and consumption can be achieved, reducing costs. Simultaneously, the liquid hydrogen transportation channel is located outside the superconducting transmission bus, which can cool the superconducting transmission bus and enable the simultaneous transmission of chemical energy and DC power. This allows for diversified storage and consumption of electrical energy, significantly improving the overall system's operating efficiency and further reducing losses and costs during power consumption. This enables deep-sea renewable energy projects to simultaneously achieve engineering feasibility for power transmission and local consumption, providing a feasible path for the efficient utilization of large-scale renewable energy and making deep-sea green electricity have practical engineering application value.

[0013] Preferably, the system also includes a heat conversion unit, a liquid nitrogen storage tank, and a liquid nitrogen delivery channel;

[0014] The liquid nitrogen storage tank is connected to one end of the liquid nitrogen delivery channel, and the other end of the liquid nitrogen delivery channel is connected to the onshore nitrogen equipment, so that the liquid nitrogen storage tank can be used to store liquid nitrogen delivered through the liquid nitrogen delivery channel;

[0015] The first hydrogen outlet of the hydrogen production device is connected to the hydrogen compressor through the heat conversion unit; the first hydrogen outlet of the hydrogen production device is connected to the hydrogen inlet of the heat conversion unit, the liquid nitrogen outlet of the liquid nitrogen storage tank is connected to the liquid nitrogen inlet of the heat conversion unit, and the hydrogen outlet of the heat conversion unit is connected to the hydrogen compressor, so that the heat conversion unit exchanges the heat of the received hydrogen to the liquid nitrogen supplied by the liquid nitrogen storage tank to pre-cool the hydrogen, and the hydrogen compressor cools and compresses the pre-cooled hydrogen.

[0016] The liquid nitrogen transport channel is installed around the liquid hydrogen transport channel on the outside, with the superconducting power transmission bus as the inner axis.

[0017] Preferably, the system also includes a nitrogen buffer tank, a synthesis tower for the ammonia synthesis unit, a circulating compressor, an ammonia separator, and a liquid ammonia conveying channel;

[0018] The heat conversion unit heats liquid nitrogen into nitrogen gas through heat exchange, and the nitrogen gas outlet of the heat conversion unit is connected to the inlet of the nitrogen gas buffer tank so that the nitrogen gas buffer tank buffers the nitrogen gas heated by heat exchange.

[0019] The outlet of the nitrogen buffer tank is connected to the nitrogen inlet of the ammonia synthesis tower, and the second hydrogen outlet of the hydrogen production unit is connected to the hydrogen inlet of the ammonia synthesis tower, so that the ammonia synthesis tower mixes and reacts nitrogen and hydrogen at a preset molar ratio to produce ammonia.

[0020] The ammonia outlet of the synthesis tower of the ammonia synthesis unit is connected to the inlet of the circulating compressor, which is used to compress the ammonia to obtain compressed ammonia.

[0021] The outlet of the circulating compressor is connected to the inlet of the ammonia separator so that the ammonia separator purifies the compressed ammonia gas;

[0022] The outlet of the ammonia separator is connected to the ammonia inlet of the heat conversion unit, so that the heat conversion unit exchanges the heat of the purified ammonia with the liquid nitrogen supplied by the liquid nitrogen storage tank.

[0023] The liquid ammonia outlet of the heat conversion unit is connected to one end of the liquid ammonia conveying channel, and the other end of the liquid ammonia conveying channel is connected to the onshore ammonia equipment.

[0024] The liquid ammonia transport channel is installed around the outer side of the superconducting power transmission bus as the inner axis.

[0025] Preferably, the heat conversion unit is a plate heat exchanger or a tubular heat exchanger with a stepped heat exchange between the front and rear stages. The liquid nitrogen exchanges heat with hydrogen through the front heat exchanger to make the hydrogen meet the pre-cooling requirements for hydrogen liquefaction treatment. The low-temperature nitrogen after temperature rise exchanges heat with ammonia through the rear heat exchanger to convert the ammonia into liquid ammonia under process pressure.

[0026] Preferably, the system further includes a circulating cooling tower and a chiller unit; the cooling water outlet of the circulating cooling tower is connected to the cooling water inlet of the heat conversion unit, and the cooling water outlet of the heat conversion unit is connected to the cooling water inlet of the circulating cooling tower; the chiller unit is connected to the circulating cooling tower and is used to cool the cooling water of the circulating cooling tower so that the cooling water in the heat conversion unit can serve as an auxiliary heat exchange medium for hydrogen and / or ammonia.

[0027] Preferably, an electrical insulation layer and a shielding layer are provided between the superconducting power transmission bus and the liquid hydrogen transport channel. The electrical insulation layer is located on the outside of the superconducting power transmission bus, and the shielding layer is located on the outside of the electrical insulation layer.

[0028] Preferably, the outer side of the liquid ammonia conveying channel is provided with a steel outer shell.

[0029] Preferably, a thermal insulation layer is provided between the liquid hydrogen delivery channel and the liquid nitrogen delivery channel, and / or between the liquid nitrogen delivery channel and the liquid ammonia delivery channel, and / or between the liquid ammonia delivery channel and the steel outer shell.

[0030] Preferably, the liquid hydrogen outlet of the hydrogen compressor is connected to one end of the liquid hydrogen delivery channel via the hydrogen storage tank, the liquid hydrogen outlet of the hydrogen compressor is connected to the inlet of the hydrogen storage tank, and the outlet of the hydrogen storage tank is connected to one end of the liquid hydrogen delivery channel.

[0031] Preferably, the system is deployed at an offshore energy station, which is a floating or anchored offshore operating platform. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the equipment configuration and layout of the energy island of the present invention;

[0033] Figure 2 This is a structural diagram of the superconducting composite pipeline of the present invention.

[0034] Reference numerals: 1. Power conversion unit; 2. Freshwater preparation unit; 3. Hydrogen production unit; 4. Hydrogen storage tank; 5. Superconducting composite pipeline; 501. Superconducting power transmission busbar; 502. Liquid hydrogen transport channel; 503. Liquid nitrogen transport channel; 504. Liquid ammonia transport channel; 505. Steel outer shell; 506. Electrical insulation layer; 507. Shielding layer; 508. Thermal insulation layer; 6. Nitrogen buffer tank; 7. Synthesis tower of ammonia synthesis unit; 8. Circulating compressor; 9. Ammonia separator; 10. Liquid nitrogen storage tank; 11. Heat conversion unit; 12. Circulating cooling tower; 13. Chilled water unit; 14. Hydrogen compressor; 15. Nitrogen compressor. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0036] Through in-depth research and improvement exploration of offshore energy consumption, the applicant discovered that in recent years, humanity's expansion into the ocean has accelerated significantly, with ultra-large-scale offshore wind power facilities extending into the deep sea on an unprecedented scale. However, this process has also exposed a deep-seated dilemma in offshore energy consumption—the massive amount of clean electricity far from load centers struggles to find an outlet. Apart from a few offshore hydrogen production and on-site oilfield consumption solutions, long-distance transmission to the shore has become almost the only realistic option. However, both direct power supply via submarine cables and indirect transmission methods that convert electricity into chemical energy carriers such as hydrogen and ammonia face high infrastructure investment and significant conversion efficiency losses: the former is constrained by ultra-long-distance transmission losses and cable manufacturing and laying costs; the latter suffers from layer-by-layer attenuation in the electrolysis, synthesis, storage, transportation, and regeneration chain, with overall efficiency generally below 30%, resulting in high cost per kilowatt-hour. This contradiction has become the core bottleneck restricting the large-scale development of offshore wind power.

[0037] Based on this, the technical solutions provided by the various embodiments of this application will be described below with reference to the accompanying drawings.

[0038] This specification presents an embodiment of a marine energy processing system, such as... Figure 1 and Figure 2 As shown, it includes a power conversion unit 1, a superconducting power transmission bus 501, a hydrogen production unit 3, a freshwater preparation unit 2, a hydrogen compressor 14, and a liquid hydrogen transport channel 502, all arranged on an offshore platform.

[0039] Power conversion unit 1 processes external green energy into direct current (DC). The first output terminal of power conversion unit 1 is electrically connected to one end of the superconducting transmission bus 501, and the other end of the superconducting transmission bus 501 is connected to onshore electrical equipment, enabling the superconducting transmission bus 501 to transmit the DC power output from the first output terminal to the onshore electrical equipment. The onshore electrical equipment may be, for example, power consumption or energy storage equipment.

[0040] The freshwater preparation device 2 desalinates seawater to obtain freshwater. The freshwater outlet of the freshwater preparation device 2 is connected to the freshwater inlet of the hydrogen production device 3. The second output terminal of the power conversion unit 1 is electrically connected to the hydrogen production device 3, enabling the hydrogen production device 3 to use the direct current output from the second output terminal to convert the freshwater into hydrogen gas through electrolysis. The first hydrogen outlet of the hydrogen production device 3 is connected to a hydrogen compressor 14, which cools and compresses the hydrogen gas to obtain liquid hydrogen. The freshwater preparation device 2 is used for seawater desalination and pure water production.

[0041] The liquid hydrogen outlet of the hydrogen compressor 14 is connected to one end of the liquid hydrogen transport channel 502, and the other end of the liquid hydrogen transport channel 502 is connected to an onshore hydrogen facility. The liquid hydrogen transport channel 502 is installed around the superconducting power transmission bus 501 as its inner axis. The onshore hydrogen facility is, for example, an onshore hydrogen utilization and storage facility.

[0042] After external green energy is connected to the energy station, it first undergoes power conversion unit 1 for energy treatment. Part of this energy is converted into DC power suitable for the hydrogen production unit 3, while the other part is boosted to high-voltage electricity using DC superconducting transmission and then transported to shore via superconducting composite pipeline 5. Simultaneously, seawater is desalinated through desalination and pure water preparation to produce freshwater that meets the requirements for hydrogen production. The freshwater produced by seawater desalination and pure water preparation is then electrolyzed by the hydrogen production unit 3 to produce hydrogen.

[0043] In one embodiment, the system further includes a heat conversion unit 11, a liquid nitrogen storage tank 10, and a liquid nitrogen delivery channel 503. The liquid nitrogen storage tank 10 is connected to one end of the liquid nitrogen delivery channel 503, and the other end of the liquid nitrogen delivery channel 503 is connected to onshore nitrogen equipment, so that the liquid nitrogen storage tank 10 is used to store liquid nitrogen transported through the liquid nitrogen delivery channel 503. There can be two liquid nitrogen storage tanks 10, each with a capacity of 50 cubic meters. Liquid nitrogen transported from the shore to the energy island via the superconducting composite pipeline 5 is directly stored in the liquid nitrogen storage tank 10.

[0044] The first hydrogen outlet of the hydrogen production unit 3 is connected to the hydrogen compressor 14 via the heat conversion unit 11; the first hydrogen outlet of the hydrogen production unit 3 is connected to the hydrogen inlet of the heat conversion unit 11, the liquid nitrogen outlet of the liquid nitrogen storage tank 10 is connected to the liquid nitrogen inlet of the heat conversion unit 11, and the hydrogen outlet of the heat conversion unit 11 is connected to the hydrogen compressor 14, so that the heat conversion unit 11 exchanges the heat of the received hydrogen to the liquid nitrogen supplied by the liquid nitrogen storage tank 10 to pre-cool the hydrogen, and the hydrogen compressor 14 cools and compresses the pre-cooled hydrogen. The liquid nitrogen transport channel 503 is installed around the outside of the liquid hydrogen transport channel 502, with the superconducting power transmission bus 501 as the inner shaft.

[0045] A portion of the obtained hydrogen gas exchanges its heat with liquid nitrogen from liquid nitrogen storage tank 10 through heat conversion unit 11 (plate heat exchanger assembly) to pre-cool the hydrogen gas. Then, it is further cooled and compressed into liquid hydrogen by hydrogen compressor 14 and stored in high-pressure hydrogen storage tank 4.

[0046] In one embodiment, the system further includes a nitrogen buffer tank 6, a synthesis tower 7 for an ammonia synthesis unit, a circulating compressor 8, an ammonia separator 9, and a liquid ammonia conveying channel 504. A heat conversion unit 11 heats liquid nitrogen into nitrogen gas through heat exchange. The nitrogen outlet of the heat conversion unit 11 is connected to the inlet of the nitrogen buffer tank 6, so that the nitrogen buffer tank 6 buffers the nitrogen gas heated by heat exchange.

[0047] The outlet of nitrogen buffer tank 6 is connected to the nitrogen inlet of synthesis tower 7 in the ammonia synthesis unit, and the second hydrogen outlet of hydrogen production unit 3 is connected to the hydrogen inlet of synthesis tower 7 in the ammonia synthesis unit, so that synthesis tower 7 in the ammonia synthesis unit mixes and reacts nitrogen and hydrogen at a preset molar ratio to produce ammonia. The ammonia outlet of synthesis tower 7 in the ammonia synthesis unit is connected to the inlet of circulating compressor 8, which is used to compress the ammonia to obtain compressed ammonia.

[0048] The outlet of the circulating compressor 8 is connected to the inlet of the ammonia separator 9 so that the ammonia separator 9 purifies the compressed ammonia gas and removes impurities. The outlet of the ammonia separator 9 is connected to the ammonia gas inlet of the heat conversion unit 11 so that the heat conversion unit 11 exchanges the heat of the purified ammonia gas to the liquid nitrogen supplied by the liquid nitrogen storage tank 10.

[0049] The liquid ammonia outlet of heat conversion unit 11 is connected to one end of liquid ammonia transport channel 504, and the other end of liquid ammonia transport channel 504 is connected to onshore ammonia equipment. Liquid ammonia transport channel 504 is installed around the outer side of liquid nitrogen transport channel 503, with superconducting power transmission bus 501 as its inner axis. Onshore ammonia equipment includes, for example, onshore ammonia use and storage equipment. Liquid hydrogen transport channel 502, liquid nitrogen transport channel 503, and liquid ammonia transport channel 504 can all be annular tubes, with adjacent channels nested together. Alternatively, liquid hydrogen transport channel 502, liquid nitrogen transport channel 503, and liquid ammonia transport channel 504 can also be circular tubes, with adjacent channels installed via supports. Liquid nitrogen transport channel 503 serves as a liquid nitrogen thermal buffer layer. Superconducting power transmission bus 501, liquid hydrogen transport channel 502, liquid nitrogen transport channel 503, and liquid ammonia transport channel 504 form a superconducting composite pipeline 5.

[0050] Nitrogen gas heated by heat exchange in heat conversion unit 11 (plate heat exchanger group) passes through a gas buffer tank and is then fed into the synthesis tower 7 of the ammonia synthesis unit. There, it is precisely mixed with another portion of the produced hydrogen gas at a 3:1 molar ratio, and after reaction, ammonia gas is produced. The ammonia gas is purified by circulating compressor 8 and ammonia separator 9, and then exchanges its own heat with liquid nitrogen from liquid nitrogen storage tank 10 through heat conversion unit 11 (plate heat exchanger group). Finally, it is exported to shore via a dedicated superconducting composite pipeline 5.

[0051] In one embodiment, the heat conversion unit 11 is a plate heat exchanger or a tubular heat exchanger in the form of a stepped heat exchange between the front and rear stages. Liquid nitrogen exchanges heat with hydrogen through the front heat exchanger, so that the hydrogen reaches the pre-cooling requirements for hydrogen liquefaction treatment. The low-temperature nitrogen after temperature rise exchanges heat with ammonia through the rear heat exchanger, so that the ammonia is converted into liquid ammonia under process pressure.

[0052] The heat conversion unit 11 (plate heat exchanger group) is a two- or three-stage stepped heat exchanger. Liquid nitrogen exchanges heat with hydrogen through one or two heat exchangers, enabling the hydrogen to meet the pre-cooling requirements for hydrogen liquefaction. The cooled nitrogen, after temperature rise, exchanges heat with ammonia through the final heat exchanger and converts the ammonia into liquid ammonia under process pressure. The heat exchanger type can be plate, tubular, or other special forms, and the number of heat exchanger stages can be adjusted to any number of stages, more than three, according to the actual process requirements.

[0053] In one embodiment, the system further includes a circulating cooling tower 12 and a chiller unit 13; the cooling water outlet of the circulating cooling tower 12 is connected to the cooling water inlet of the heat conversion unit 11, and the cooling water outlet of the heat conversion unit 11 is connected to the cooling water inlet of the circulating cooling tower 12; the chiller unit 13 is connected to the circulating cooling tower 12 and is used to cool the cooling water of the circulating cooling tower 12 so that the cooling water in the heat conversion unit 11 serves as an auxiliary cooling medium for hydrogen and / or ammonia.

[0054] In addition to the liquid nitrogen transferred to the platform via the superconducting composite pipeline 5, the energy island's cold source can also be provided by a cooling system consisting of a circulating cooling tower 12 and a chilled water unit 13.

[0055] In one embodiment, an electrical insulation layer 506 and a shielding layer 507 are provided between the superconducting power transmission bus 501 and the liquid hydrogen transport channel 502. The electrical insulation layer 506 is disposed on the outside of the superconducting power transmission bus 501, and the shielding layer 507 is disposed on the outside of the electrical insulation layer 506.

[0056] In one embodiment, a steel outer shell 505 is provided on the outside of the liquid ammonia delivery channel 504.

[0057] In one embodiment, a thermal insulation layer 508 is provided between the liquid hydrogen transport channel 502 and the liquid nitrogen transport channel 503, and / or between the liquid nitrogen transport channel 503 and the liquid ammonia transport channel 504, and / or between the liquid ammonia transport channel 504 and the steel outer shell 505.

[0058] The energy generated by the energy island of this invention mainly includes: electrical energy, liquid hydrogen, and liquid ammonia. The main chemical consumed by the energy island of this invention is liquid nitrogen. These chemicals or electrical energy are all transported through a specially designed superconducting composite pipeline 5. Electrical energy, liquid hydrogen, and liquid ammonia are supplied from the energy island to the shore, while liquid nitrogen is supplied from the shore to the energy island. The superconducting composite pipeline 5 has a four-layer structure from the inside out. The four layers, from the inside out, are: superconducting DC power supply bus - liquid hydrogen transport layer - liquid nitrogen transport layer - liquid ammonia transport layer.

[0059] The superconducting composite pipeline 5 is essentially a multi-stage evaporative shielded insulation structure. The central superconducting busbar operates at 20K, the second layer (liquid hydrogen) at 20K, the third layer (liquid nitrogen) at 77K, and the fourth layer (liquid ammonia) at 240K. Environmental heat penetrates layer by layer inwards; each time it passes through a cold shield, the heat is absorbed by the latent heat of vaporization of the working fluid in that layer, resulting in a stepwise temperature decrease. This effectively improves the insulation efficiency of the entire system.

[0060] An electrical insulation layer 506 and a shielding layer 507 are installed between the superconducting DC bus layer and the liquid hydrogen layer. A thermal insulation layer 508 is installed between the chemical transport layers. A thermal insulation layer 508 is installed between the outermost liquid ammonia layer and the steel protective pipe. The outermost layer of the entire piping system is a steel protective pipe for physical protection.

[0061] The design of this superconducting composite transmission pipeline utilizes a buffer relationship between various liquid chemicals with different thermodynamic characteristics to facilitate heat transfer. The core idea is to use the evaporation heat of three cryogenic working fluids to intercept heat intruding from the environment layer by layer, reducing the overall thermodynamic loss of the system. While meeting the temperature requirements for cryogenic superconducting power transmission, it significantly improves transmission efficiency and reduces transportation costs. Compared to transporting liquid hydrogen, liquid nitrogen, or liquid ammonia separately, this scheme innovatively couples superconducting DC power transmission capabilities, forming an integrated cold-electricity transmission system that combines high efficiency and reliability, while significantly reducing transportation costs.

[0062] Liquid nitrogen transported from the shore to the energy island can serve as a reliable cold source for pre-cooling hydrogen or for cooling / liquefying ammonia that needs to be exported, reducing the power and losses of the energy island's own refrigeration equipment. This also means that the entire system does not require additional electricity for heating and revaporizing the liquid nitrogen used as a raw material for ammonia production.

[0063] This invention, taking into account the actual situation of offshore energy development, explores a technical route with practical applicability. Through a unique power consumption scheme on the energy island, power is systematically and progressively consumed at different stages. By fully utilizing the transmission capabilities provided by the superconducting composite transmission pipeline, the operating efficiency of the entire system is significantly improved, while losses and costs in the entire power consumption process are reduced.

[0064] In one embodiment, the liquid hydrogen outlet of the hydrogen compressor 14 is connected to one end of the liquid hydrogen delivery channel 502 via a hydrogen storage tank 4. The liquid hydrogen outlet of the hydrogen compressor 14 is connected to the inlet of the hydrogen storage tank 4, and the outlet of the hydrogen storage tank 4 is connected to one end of the liquid hydrogen delivery channel 502. The hydrogen storage tank 4 is a high-pressure hydrogen storage tank 4.

[0065] In one embodiment, the system is deployed at an offshore energy station, serving as an offshore energy island. The offshore energy station of the present invention is based on an offshore operating platform that is floating, anchored, or otherwise positioned.

[0066] In one embodiment, the system further includes a nitrogen compressor 15 for nitrogen compression.

[0067] In one embodiment, the DC power output from the second output terminal of the electrical conversion unit is also used for the daily power supply of the system.

[0068] The platform can be equipped with multiple devices to suit various needs. For example, the number and scale of storage tanks can be adjusted according to actual operating conditions. The composite superconducting pipeline can be circular or other suitable geometric shapes. The heat exchanger can be plate, tubular, or other special types, and the number of stages can be adjusted to any number of stages, up to three, depending on the requirements of the actual process flow.

[0069] The present invention can also utilize traditional energy storage methods such as lithium batteries or supercapacitors, DC superconducting transmission, or other chemical energy conversion and transportation methods. However, the individual costs of these methods are very high, and they do not meet the conditions for practical application in the engineering stage.

[0070] This invention provides an energy processing and transmission solution for a large-scale offshore energy island, addressing the problem of energy consumption in deep-sea areas. The energy island uses a rectifier to convert AC power from nearby power generation units into stable DC power, providing DC power for subsequent electrochemical processes. A portion of this electricity drives a proton exchange membrane or alkaline electrolyzer to decompose desalinated seawater into hydrogen and oxygen under the action of a catalyst. The resulting hydrogen is purified to a purity of over 99.99%, then undergoes multi-stage compression, pre-cooling, and expansion refrigeration cycles to reach liquefaction temperature, yielding the finished liquid hydrogen product. Another portion of the hydrogen is mixed with nitrogen supplied from the shore at a 3:1 molar ratio and synthesized into ammonia using an iron-based catalyst under rated temperature and pressure conditions. The reacted gases are cooled and separated, unreacted gases are recycled, and the liquid ammonia product is stored in cryogenic tanks at atmospheric or slightly positive pressure. Liquid nitrogen supplied from the shore provides deep pre-cooling for the liquid hydrogen system via a heat exchanger, while its vapors maintain the liquid ammonia temperature, preventing vaporization losses. This tiered cooling strategy significantly reduces cooling power consumption, forming a synergistic cooling mode of "nitrogen in, hydrogen out," thus optimizing overall energy efficiency. The entire system synchronously outputs DC power that can be directly transmitted via submarine cables, as well as liquid hydrogen and liquid ammonia chemical energy that can be transported by ship or pipeline, achieving diversified storage and utilization of electrical energy. This electricity-hydrogen-ammonia synergistic conversion mode effectively solves the problems of strong volatility and high transmission costs of deep-sea wind power, providing a feasible path for the efficient utilization of large-scale renewable energy.

[0071] Furthermore, the energy island of this invention is equipped with a special superconducting composite energy transmission pipeline for coordinated operation. This pipeline adopts a multi-layered coaxial structure: a superconducting DC power supply bus at the center, and outer pipelines for liquid hydrogen, liquid nitrogen, and liquid ammonia arranged sequentially from the inside out according to the thermodynamic properties of the media. Specifically, the liquid hydrogen and liquid ammonia pipelines are responsible for transporting the hydrogen and ammonia produced by the energy island to the shore; the liquid nitrogen pipeline transports the liquid nitrogen from the shore to the energy island in the opposite direction; and the three outer chemical pipelines provide a continuous cooling source for the DC superconducting power transmission and distribution system. This integrated design achieves the synchronous and efficient transmission of electrical energy, chemical energy, and cooling energy.

[0072] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A marine energy processing system, characterized in that, It includes a power conversion unit, a superconducting power transmission bus, a hydrogen production unit, a freshwater preparation unit, a hydrogen compressor, and a liquid hydrogen transportation channel; The power conversion unit processes external green energy and converts it into direct current (DC). The first output terminal of the power conversion unit is electrically connected to one end of a superconducting transmission bus, and the other end of the superconducting transmission bus is connected to onshore electrical equipment, so that the superconducting transmission bus can transmit the DC power output from the first output terminal to the onshore electrical equipment. The freshwater preparation device desalinates seawater to obtain freshwater. The freshwater outlet of the freshwater preparation device is connected to the freshwater inlet of the hydrogen production device. The second output terminal of the power conversion unit is electrically connected to the hydrogen production device so that the hydrogen production device uses the direct current output from the second output terminal to convert the freshwater into hydrogen through electrolysis. The first hydrogen outlet of the hydrogen production device is connected to the hydrogen compressor, which cools and compresses the hydrogen to obtain liquid hydrogen. The liquid hydrogen outlet of the hydrogen compressor is connected to one end of the liquid hydrogen delivery channel, and the other end of the liquid hydrogen delivery channel is connected to the onshore hydrogen equipment. The liquid hydrogen transport channel is installed around the superconducting power transmission bus as its inner axis.

2. The marine energy processing system according to claim 1, characterized in that, The system also includes a heat conversion unit, a liquid nitrogen storage tank, and a liquid nitrogen delivery channel; The liquid nitrogen storage tank is connected to one end of the liquid nitrogen delivery channel, and the other end of the liquid nitrogen delivery channel is connected to the onshore nitrogen equipment, so that the liquid nitrogen storage tank can be used to store liquid nitrogen delivered through the liquid nitrogen delivery channel; The first hydrogen outlet of the hydrogen production device is connected to the hydrogen compressor through the heat conversion unit; the first hydrogen outlet of the hydrogen production device is connected to the hydrogen inlet of the heat conversion unit, the liquid nitrogen outlet of the liquid nitrogen storage tank is connected to the liquid nitrogen inlet of the heat conversion unit, and the hydrogen outlet of the heat conversion unit is connected to the hydrogen compressor, so that the heat conversion unit exchanges the heat of the received hydrogen to the liquid nitrogen supplied by the liquid nitrogen storage tank to pre-cool the hydrogen, and the hydrogen compressor cools and compresses the pre-cooled hydrogen. The liquid nitrogen transport channel is installed around the liquid hydrogen transport channel on the outside, with the superconducting power transmission bus as the inner axis.

3. The marine energy processing system according to claim 2, characterized in that, The system also includes a nitrogen buffer tank, a synthesis tower for the ammonia synthesis unit, a circulating compressor, an ammonia separator, and a liquid ammonia conveying channel; The heat conversion unit heats liquid nitrogen into nitrogen gas through heat exchange, and the nitrogen gas outlet of the heat conversion unit is connected to the inlet of the nitrogen gas buffer tank so that the nitrogen gas buffer tank buffers the nitrogen gas heated by heat exchange. The outlet of the nitrogen buffer tank is connected to the nitrogen inlet of the ammonia synthesis tower, and the second hydrogen outlet of the hydrogen production unit is connected to the hydrogen inlet of the ammonia synthesis tower, so that the ammonia synthesis tower mixes and reacts nitrogen and hydrogen at a preset molar ratio to produce ammonia. The ammonia outlet of the synthesis tower of the ammonia synthesis unit is connected to the inlet of the circulating compressor, which is used to compress the ammonia to obtain compressed ammonia. The outlet of the circulating compressor is connected to the inlet of the ammonia separator so that the ammonia separator purifies the compressed ammonia gas; The outlet of the ammonia separator is connected to the ammonia inlet of the heat conversion unit, so that the heat conversion unit exchanges the heat of the purified ammonia with the liquid nitrogen supplied by the liquid nitrogen storage tank. The liquid ammonia outlet of the heat conversion unit is connected to one end of the liquid ammonia conveying channel, and the other end of the liquid ammonia conveying channel is connected to the onshore ammonia equipment. The liquid ammonia transport channel is installed around the outer side of the superconducting power transmission bus as its inner axis.

4. The marine energy processing system according to claim 3, characterized in that, The heat conversion unit is a plate heat exchanger or a tubular heat exchanger in the form of a stepped heat exchange between the front and rear stages. The liquid nitrogen exchanges heat with hydrogen through the front heat exchanger, so that the hydrogen reaches the pre-cooling requirements for hydrogen liquefaction treatment. The low-temperature nitrogen after temperature rise exchanges heat with ammonia through the rear heat exchanger, so that the ammonia is converted into liquid ammonia under process pressure.

5. The marine energy processing system according to claim 3, characterized in that, The system also includes a circulating cooling tower and a chiller unit; the cooling water outlet of the circulating cooling tower is connected to the cooling water inlet of the heat conversion unit, and the cooling water outlet of the heat conversion unit is connected to the cooling water inlet of the circulating cooling tower; the chiller unit is connected to the circulating cooling tower and is used to cool the cooling water of the circulating cooling tower so that the cooling water in the heat conversion unit can be used as an auxiliary heat exchange medium for hydrogen and / or ammonia.

6. The marine energy processing system according to claim 1, characterized in that, An electrical insulation layer and a shielding layer are provided between the superconducting power transmission bus and the liquid hydrogen transport channel. The electrical insulation layer is located on the outside of the superconducting power transmission bus, and the shielding layer is located on the outside of the electrical insulation layer.

7. The marine energy processing system according to claim 3, characterized in that, The liquid ammonia delivery channel is equipped with a steel outer shell.

8. The marine energy processing system according to claim 3, characterized in that, A thermal insulation layer is provided between the liquid hydrogen transport channel and the liquid nitrogen transport channel, and / or between the liquid nitrogen transport channel and the liquid ammonia transport channel, and / or between the liquid ammonia transport channel and the steel outer shell.

9. The marine energy processing system according to claim 1, characterized in that, The liquid hydrogen outlet of the hydrogen compressor is connected to one end of the liquid hydrogen delivery channel via the hydrogen storage tank. The liquid hydrogen outlet of the hydrogen compressor is connected to the inlet of the hydrogen storage tank, and the outlet of the hydrogen storage tank is connected to one end of the liquid hydrogen delivery channel.

10. The marine energy processing system according to claim 1, characterized in that, The system is deployed at an offshore energy station, which is a floating or anchored offshore operating platform.

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