Sea island electricity-hydrogen-water-heat combined supply system driven by wind, light and wave energy and operation method

Abstract

The invention discloses an island electricity-hydrogen-water-heat combined supply system driven by wind, light and wave energy and an operation method, and belongs to the field of renewable energy utilization and island energy supply. The system comprises a reversible solid oxide battery module, a fresh water preparation module, a wind, light and wave energy power generation module, an air conveying module, a hydrogen conveying module and a system scheduling module, and can supply electricity, heat, water, hydrogen and the like to an island at the same time. When the renewable energy electric power is surplus, the rSOC module operates in an electrolysis mode, and the surplus renewable energy electric power is converted into hydrogen and water vapor; and when the renewable energy power is insufficient, the rSOC module operates in a power generation mode, and the hydrogen stored in the electrolysis mode is utilized to generate power. In addition, the rSOC operates at 600-1000 DEG C, and high-temperature waste heat of the rSOC can be efficiently recycled in a stepped mode. Therefore, electricity-hydrogen-water-heat poly-generation can be achieved, and the comprehensive utilization efficiency of island energy and the energy supply stability are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of renewable energy utilization and island energy supply, and particularly relates to an island electricity-hydrogen-water-heat combined supply system driven by wind, light and wave energy and an operation method thereof. Background Art

[0002] Due to the limitations of geographical environment and construction conditions, the marine renewable energies suitable for development and utilization on islands are generally wind energy, solar energy and wave energy. However, the power generation of a single renewable energy is volatile, and the traditional island energy supply mode mainly based on diesel power generation has problems such as high economic cost, large pollutant emissions and difficult transportation. In view of the intermittency and instability of the above-mentioned energies, it is difficult to provide stable electric energy for islands by using a single renewable energy. Therefore, a renewable energy multi-energy complementary power generation technology is adopted, and the multi-energy complementary power generation couples two or more power generation methods and operates jointly to overcome the problems such as poor stability of electric energy output and insufficient supply caused by separate operation.

[0003] At present, most of the island energy systems use diesel generators as supplementary power sources and are combined with energy storage device battery packs. However, the islands are far from the mainland, the material transportation is inconvenient, and the diesel generators generate large noises. The technology of Reversible Solid Oxide Cell (rSOC) can realize two functions of electrolyzing water to produce hydrogen and fuel cell power generation on the same device. It can not only be used as a supplementary power source for supplementary power generation, but also be used as an energy storage device for energy storage, reducing equipment and the system complexity.

[0004] At present, there are already energy systems using hydrogen-oxygen fuel cells for power generation in the island energy systems. However, this energy system needs to first use electrolysis equipment to electrolyze seawater to produce hydrogen and store the hydrogen. When the renewable energy power generation is insufficient, the hydrogen-oxygen fuel cell is used for power generation. This system needs to use two sets of devices to complete the functions of electrolyzing water to produce hydrogen and fuel cell power generation, resulting in increased investment costs and larger equipment redundancy, while rSOC can alternately realize the functions of power generation and power storage on the same device.

[0005] In the island energy system, most consider the preparation of electricity and fresh water. The heating of islands mostly uses boilers or electric heating for heating, and little considers waste heat heating. The working temperature of rSOC is 600-1000 °C, and the heat released by the chemical reaction can be recovered through a series of heat recovery devices and supplied to users for heating, improving the energy utilization efficiency. Summary of the Invention

[0006] To overcome the above-mentioned drawbacks of the existing technologies, the object of the present invention is to provide an island electricity-hydrogen-water-heat combined supply system driven by wind, light, and wave energy and an operation method thereof, using rSOC as the core energy conversion device and considering the comprehensive utilization of its waste heat, so as to solve the current situation of tight energy supply in the existing island energy system.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] An island electricity-hydrogen-water-heat combined supply system driven by wind, light, and wave energy, comprising:

[0009] The rSOC module has two operating modes: a solid oxide electrolysis cell (SOEC) and a solid oxide fuel cell (SOFC). In the SOEC mode, as a solid oxide electrolysis cell, it receives the surplus renewable energy power from the wind, light, and wave energy power generation module and the fresh water from the hydrogen delivery module, undergoes the electrolytic water hydrogen production reaction, uses the surplus renewable energy power for electrolytic water hydrogen production, and stores the generated hydrogen for energy storage; in the SOFC mode, as a solid oxide fuel cell, it receives the air from the air delivery module and the hydrogen from the hydrogen delivery module for electrochemical reaction power generation; the generated power is transmitted to the system dispatching module;

[0010] The fresh water preparation module uses solar thermal-driven two-stage flash evaporation technology to produce fresh water from seawater for use in the island artificial base, and supplies it to the rSOC module as hydrogen production water in the SOEC mode;

[0011] The wind, light, and wave energy power generation module generates electricity based on three renewable energy sources: wind energy, light energy, and wave energy. The obtained power is supplied to the island artificial base in the SOEC mode and used as electrolysis power for the rSOC module; in the SOFC mode, it is jointly supplied to the island artificial base with the power obtained from the rSOC module to meet its power demand;

[0012] The air delivery module provides the oxygen required for the electrochemical reaction in the SOFC mode, and at the same time receives the remaining air that has not reacted in the rSOC module to preheat the air. After preheating, the remaining air is transported to the burner in the rSOC module for combustion;

[0013] The hydrogen delivery module stores the hydrogen generated when the rSOC module operates in the SOEC mode and provides the hydrogen required for the electrochemical reaction for the rSOC module in the SOFC mode;

[0014] The system scheduling module matches the hourly supply of renewable energy with the electricity demand based on the electricity demand and the output characteristics of wind energy, solar energy, and wave energy power generation, and controls the rSOC module to switch to the SOEC or SOFC mode accordingly.

[0015] In one embodiment, in the SOEC mode, the rSOC module uses surplus renewable energy power to electrolyze fresh water to produce hydrogen. At this time, the rSOC acts as a solid oxide electrolyzer. The fuel electrode receives the fresh water transported by the hydrogen transport module. Water vapor obtains electrons at the fuel electrode to generate hydrogen and oxygen ions. The oxygen ions pass through the electrolyte to the air electrode to release electrons to generate oxygen. The mixture of hydrogen and water vapor produced by the fuel electrode is transported to the water vapor preheater in the hydrogen transport module, first used to preheat the imported fresh water, and then separated. The hydrogen is stored, and its high-temperature waste heat is used by the island artificial base.

[0016] In the SOFC mode, the hydrogen prepared in the SOEC mode reacts electrochemically with air to generate electricity. At this time, the rSOC acts as a solid oxide fuel cell. The fuel electrode receives the hydrogen from the hydrogen transport module, and the air electrode receives the air from the air transport module. After the hydrogen and air are pressurized and preheated respectively, they are introduced into the fuel electrode and the air electrode to undergo an electrochemical reaction, directly converting the stored chemical energy into electrical energy to jointly meet the electricity demand of the island artificial base with renewable electricity. The air is preheated and adheres to the surface of the air electrode, and the hydrogen is preheated and adheres to the surface of the fuel electrode; the hydrogen loses electrons to become hydrogen ions, and the electrons flow through the external circuit to the air electrode, where they combine with oxygen to form oxygen ions. The oxygen ions pass through the electrolyte to the fuel electrode and combine with hydrogen ions to form water. After the reaction, the unreacted hydrogen and the reaction product water vapor are output from the fuel electrode to the afterburner, and the unreacted air is output from the air electrode to the air transport module to preheat the air. After preheating, it enters the afterburner to burn, generating high-temperature flue gas and water vapor to further increase the reaction temperature. The high-temperature flue gas and water vapor are transported to the hydrogen transport module.

[0017] In one embodiment, the fresh water preparation module is a solar thermal-driven two-stage flash evaporation device. First, seawater is pumped into regenerator 1 and regenerator 2 for preheating. After preheating, it enters the solar collector. The solar collector converts solar radiation into heat energy to heat the seawater. The heated seawater enters the first-stage flash tank (high-pressure stage), and part of the seawater quickly evaporates into water vapor. The water vapor enters regenerator 2 and condenses and releases heat to become fresh water, which enters the fresh water tank for storage. Another part of the seawater continues to enter the second-stage flash tank, and part of the seawater quickly evaporates into water vapor. The water vapor enters regenerator 1 and condenses and releases heat to become fresh water, which enters the fresh water tank for storage. After the two-stage flash evaporation is completed, the concentrated brine is discharged into the sea;

[0018] In the SOEC mode, the prepared fresh water is transported to the hydrogen module for preheating and then supplied to the rSOC module as a raw material for the electrolysis of water to produce hydrogen; in the SOFC mode, the fresh water, a product of the hydrogen and oxygen fuel cell reaction, is received from the rSOC module for storage.

[0019] In one embodiment, the renewable energy sources on which the wind, light and wave energy generation modules are based include one or more of solar energy, wind energy and wave energy, and a DC / AC inverter is used for AC / DC conversion; wherein, the wind energy generation system adopts small and medium-sized horizontal axis wind turbines or vertical axis wind turbines according to the wind speed characteristics of the island, and adopts permanent magnet synchronous motors for wind power generation, and the generated AC power is converted into usable power through rectification-inversion; the photovoltaic power generation system adopts high-efficiency monocrystalline silicon to improve the efficiency of light energy conversion; the wave energy generation system adopts a point absorption wave energy generator to adapt to the island wave conditions, and the generated AC power is converted into usable power through the rectification-inversion process; in the SOEC mode, the renewable energy generation module transmits electricity to the island artificial base to meet the needs of the artificial base, and at the same time transmits electricity to the rSOC module for water electrolysis hydrogen production reaction; in the SOFC mode, the renewable energy power and the power generation of the rSOC module jointly meet the power load demand of the island artificial base.

[0020] In one embodiment, the air delivery module includes a fan and an air preheater;

[0021] In SOFC mode, air is transported to the air electrode of the rSOC module through the fan to remove the reaction heat and provide the oxygen required for the electrochemical reaction. At the same time, the unreacted air at the air electrode outlet of the rSOC module is received and preheated in the air preheater. After the preheating is completed, the remaining unreacted air at the air electrode outlet is transported to the after-burner of the rSOC module for complete combustion; the fresh water obtained from the combustion is used to preheat the hydrogen at the fuel electrode inlet and then stored, and the waste heat of the high-temperature flue gas is transported to the system scheduling module for use in the island artificial base.

[0022] In one embodiment, the hydrogen delivery module receives fresh water from the fresh water preparation module in the SOEC mode, and after being preheated, delivers it to the rSOC module fuel electrode as a raw material for the electrolysis of water to produce hydrogen reaction. The mixture of hydrogen and water vapor at the outlet of the rSOC module fuel electrode is preheated with fresh water in a water vapor preheater, and enters the condenser after preheating; the hydrogen is cooled in the condenser and finally stored in the hydrogen storage tank, and the water vapor condenses and releases heat in the condenser to become liquid water, which is delivered to the fresh water preparation module for storage; the oxygen generated by the air electrode of the rSOC module is received, and the oxygen is delivered to the system scheduling module after preheating the fresh water in the water vapor preheater;

[0023] In SOFC mode, hydrogen is sent into the fuel preheater through a compressor, and after preheating, it is transported to the air electrode of the rSOC module as a raw material for the electrochemical reaction; at the same time, it receives a mixture of high-temperature flue gas and water vapor from the outlet of the afterburner in the rSOC module, and the mixture preheats the hydrogen in the fuel preheater. The water vapor condenses and releases heat to form liquid water, which is transported to the fresh water preparation module for storage, and the high-temperature flue gas is transported to the system scheduling module to provide heat for the artificial base on the island.

[0024] In one embodiment, the system scheduling module controls the rules for switching between the two operating modes as follows:

[0025] When the electricity demand of the artificial island base is less than the power generation of renewable energy, the SOEC mode is adopted to convert the surplus renewable electricity into hydrogen for storage; when the electricity demand of the artificial island base is greater than the power generation of renewable energy, the SOFC mode is adopted, using the stored hydrogen as fuel to supplement the power supply for the artificial base, thereby smoothing the output fluctuations of renewable energy such as wind, light, and wave energy, and achieving all-weather energy self-consistency.

[0026] In one embodiment, in SOEC mode, the system scheduling module receives electricity from the renewable energy power generation module, receives fresh water from the fresh water preparation module, and receives waste heat from the hydrogen module for use by the island artificial base; in SOFC mode, the system scheduling module simultaneously receives electricity from the renewable energy power generation module and the rSOC module, receives fresh water from the fresh water preparation module, and receives waste heat from the hydrogen module.

[0027] Another aspect of the present invention further provides an operation method of the aforementioned wind, solar and wave energy driven island electricity-hydrogen-water-heat cogeneration system, comprising:

[0028] Produce and provide fresh water to artificial island bases based on fresh water preparation modules;

[0029] Monitor the electrical load and renewable energy power generation of the artificial island base. When the electrical load of the artificial island base is less than the renewable energy power generation, the SOEC mode is adopted, and the rSOC module uses renewable electricity and fresh water to electrolyze water to produce hydrogen for energy storage; when the electrical load of the artificial island base is greater than the renewable energy power generation, the SOFC mode is adopted, using the stored hydrogen as fuel for electrochemical reaction to generate electricity, supplementing the power supply for the artificial island base, thereby achieving all-weather energy self-consistency.

[0030] In one embodiment, an air delivery module is used to provide oxygen required for electrochemical reaction in SOFC mode, and the heat is used to preheat the inlet air so that the air inlet temperature reaches the reaction condition.

[0031] The hydrogen produced by electrolyzing water is exchanged with fresh water, the raw material for electrolyzing water, using a hydrogen transportation module in the SOEC mode, and the fresh water, the product of the electrochemical reaction, is exchanged with hydrogen, the raw material for the electrochemical reaction, in the SOFC mode. The waste heat after heat exchange is used by the artificial base on the island, and the products after heat exchange are stored.

[0032] Compared with the traditional island energy system in the prior art, the beneficial effects of the present invention are as follows:

[0033] In the previous traditional island energy system, a storage battery was required as an energy storage device to store electrical energy, and a diesel generator was also required as a supplementary power source for supplementary power generation. The island energy system designed by the present invention couples the rSOC innovative technology, and two functions of fuel cell power generation and electrolytic cell energy storage can be realized on the same device rSOC. By using rSOC to absorb the renewable energy on the island to achieve hydrogen production and energy storage by electrolysis of water, and using hydrogen storage power generation to smooth the unstable output of wind, light, and ocean energy, the island can achieve energy self-sufficiency; since the operating temperature of rSOC is as high as 500 - 1000 °C, through a reasonable system configuration, the waste heat utilization of the high-temperature tail gas during the system power generation and hydrogen production processes is fully considered to meet the heating demand of the artificial base on the island and achieve polygeneration of electricity - hydrogen - water - heat, realizing diversified and clean utilization of energy; based on the supply - demand matching characteristics of the load of the artificial base on the island and the output of renewable energy power generation, two operating modes are controlled and switched: SOEC and SOFC. In the scenario of excess renewable power, the renewable power is converted into hydrogen for storage through the SOEC mode; in the scenario of insufficient renewable power, the SOFC mode is adopted to supplement power supply for the artificial base with the stored hydrogen as fuel, so as to achieve all-weather energy self-consistency and have a strong energy guarantee ability. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0035] Figure 1 It is a system schematic diagram of an island electricity - hydrogen - water - heat combined supply system driven by wind - light - wave energy provided by an embodiment of the present invention.

[0036] Figure 2 It is a system working principle diagram in the SOFC operating mode provided by an embodiment of the present invention.

[0037] Figure 3 It is a system working principle diagram in the SOEC operating mode provided by an embodiment of the present invention.

[0038] Figure 4The operation strategy diagram provided by the embodiment of the present invention.

[0039] Figure 5 The output characteristic diagram of renewable energy provided by the embodiment of the present invention.

[0040] Figure 6 The system performance diagram provided by the embodiment of the present invention.

[0041] Figure 7 The system output diagram provided by the embodiment of the present invention. Detailed implementation manners

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. The terms "connected", "connected", and "communicated" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0044] Most existing renewable energy island power supply systems use traditional prime movers such as diesel engines as supplementary power sources and storage batteries for electricity storage. The equipment redundancy is high, and the energy storage capacity is limited. Therefore, the present invention introduces the rSOC technology that can realize the functions of electrolytic water hydrogen production and fuel cell power generation in the same device to suppress the output fluctuations of renewable energy such as wind, light, and wave energy. Please refer to Figure 1 As shown, the present invention is an island power-hydrogen-water-thermal combined supply system driven by wind, light, and wave energy, including an rSOC module 1, a fresh water preparation module 2, a wind, light, and wave energy power generation module 3, an air delivery module 4, a hydrogen delivery module 5, and a system scheduling module 6.

[0045] The rSOC module 1 refers to a Reversible Solid Oxide Cell (rSOC). In the present invention, there are two operating modes, namely SOEC (Solid Oxide Electrolysis Cell) and SOFC (Solid Oxide Fuel Cell). In the SOEC mode, the rSOC acts as a solid oxide electrolysis cell to use surplus renewable energy power for electrolyzing water to produce hydrogen, and stores the generated hydrogen for energy storage; in the SOFC mode, the rSOC acts as a solid oxide fuel cell, and electrochemically reacts the stored hydrogen with oxygen in the air to generate electricity as a supplementary power source.

[0046] The fresh water preparation module 2 includes a recuperator, a solar collector, a flash tank, and fresh water tank equipment. This module is a solar thermal-driven two-stage flash evaporation device. Seawater is pumped into the recuperator by a seawater pump, preheated by the generated high-temperature steam, and then flows into the solar collector; the solar collector uses the heat of solar energy to heat the seawater, and the heated seawater flows into the flash tank; in the flash tank, due to the pressure reduction, the hot water rapidly evaporates to produce water vapor; the water vapor enters the recuperator, where the high-temperature water vapor heats the incoming seawater for heat recovery, and at the same time, it liquefies and releases heat to form fresh water; the fresh water cooled by the recuperator finally flows into the fresh water tank and is stored, and supplies fresh water as a raw material for electrolyzing water to produce hydrogen for the rSOC module 1 in the SOEC mode.

[0047] The wind, light, and wave energy power generation module 3 includes a solar power generation device, a wind power generation device, a wave energy power generation device, and a DC (Direct Current) / AC (Alternating Current) inverter. The wind power generation device, according to the wind speed characteristics of the island, uses a small or medium-sized horizontal axis wind turbine or a vertical axis wind turbine, and uses a permanent magnet synchronous motor for wind power generation. The generated alternating current is converted into available power through rectification-inversion; the photovoltaic power generation device uses high-efficiency single crystal silicon to improve the light energy conversion efficiency; the wave energy power generation device uses a point absorption type wave energy generator to adapt to the wave conditions of the island, and the generated alternating current is converted into available power through the rectification-inversion process. It supplies power to the artificial base and supplies power to the rSOC for electrolyzing seawater to produce hydrogen in the SOEC mode; in the SOFC mode, it supplies power to the artificial base together with the rSOC module 1.

[0048] The air delivery module 4 includes a fan and an air preheater. In the SOFC mode, it supplies air as a raw material for the rSOC module 1 to electrochemically react with hydrogen to generate electricity, and takes away the excess heat in the reaction.

[0049] The hydrogen delivery module 5 has two main functions, namely storing the hydrogen generated by the rSOC module 1 in the SOEC mode and delivering the stored hydrogen to the fuel electrode of the rSOC module 1 in the SOFC mode to meet the hydrogen demand for the electrochemical reaction.

[0050] The system scheduling module 6 includes an operation mode controller 62. The operation mode controller 62 can control the switching between two operation modes, SOEC and SOFC, based on the hourly quantitative matching characteristics of the power consumption load of the island artificial base 61 and the supply and demand of renewable energy power generation. When the power load of the artificial base is less than the renewable energy power generation, the SOEC mode is adopted to convert renewable electricity into hydrogen for storage; when the power load of the artificial base is greater than the renewable energy power generation, the SOFC mode is adopted to supplement the power supply for the artificial base with the stored hydrogen as fuel, so as to achieve all-weather energy self-consistency and have a strong energy guarantee ability.

[0051] For the further structures and collaborative working principles of the modules of the present invention, reference is made to Figure 2 and Figure 3 as shown.

[0052] The rSOC module 1 mainly includes a fuel electrode, an electrolyte, and an air electrode, which constitute the stack 11.

[0053] In the SOEC mode, it electrolyzes water to produce hydrogen. The inlet water is heated to form water vapor, and the water vapor undergoes an electrolysis reaction at the fuel electrode to generate hydrogen. Oxygen ions pass through the electrolyte to the air electrode to generate oxygen. The product of the air electrode can preheat the inlet air to maintain the reaction environment. The mixture of hydrogen and water vapor produced by the fuel electrode is first used to preheat the inlet fresh water to improve energy efficiency, and then separated. The hydrogen is stored, and its high-temperature waste heat is used by the island artificial base. Further, in this mode, the rSOC module 1 is connected to the wind, light, and wave energy power generation module 3 and the hydrogen delivery module 5, receives the power from the wind, light, and wave energy power generation module 3 for electrolyzing water to produce hydrogen, receives the preheated fresh water from the hydrogen delivery module 5 as a raw material, and at the same time delivers and stores the hydrogen generated by the electrolysis reaction of water to the hydrogen delivery module 5.

[0054] In the SOFC mode, it generates electricity through an electrochemical reaction. After the hydrogen and air are pressurized and preheated respectively, they are introduced into the fuel electrode and the air electrode to undergo an electrochemical reaction, so as to directly convert the stored chemical energy into electrical energy, and jointly meet the electrical demand of the island artificial base with the renewable electricity provided by the wind, light, and wave energy power generation module 3.

[0055] The rSOC module 1 of the present invention can cross-implement two functions of fuel cell power generation and electrolytic cell energy storage in a single device. In the fuel cell mode, it converts chemical energy into electrical energy, and in the electrolysis mode, it converts electrical energy into chemical energy. Its working principle integrates the working mechanisms of SOFC and SOEC. Through the energy conversion between electrical energy and hydrogen energy, the rSOC module 1 can not only act as a supplementary energy source as a fuel cell for power generation, but also act as an energy storage device as an electrolytic cell to electrolyze seawater to produce hydrogen for storage, improving the stability of power output and the energy guarantee ability.

[0056] Among them, when the rSOC module 1 realizes the fuel cell power generation function, hydrogen and air first enter the fuel preheater and the air preheater respectively under the pressure of the compressor, reach the inlet temperature requirement of the intake port, and then are respectively introduced into the fuel electrode and the air electrode to carry out an electrochemical reaction, directly converting the stored chemical energy into electrical energy, jointly meeting the electrical demand of the artificial base with renewable electricity. When the rSOC module 1 realizes the electrolytic cell energy storage function, water vapor undergoes an electrolysis reaction at the fuel electrode to generate hydrogen, and oxygen ions pass through the electrolyte to reach the air electrode to generate oxygen. The mixture of hydrogen and water vapor produced at the fuel electrode first enters the water vapor preheater to preheat the inlet fresh water, and then enters the condenser to separate water and hydrogen, and the hydrogen is sent to the hydrogen storage tank for storage.

[0057] The fresh water preparation module 2 of the present invention mainly includes a recuperator, a flash tank, a solar collector 23 and a fresh water tank 26. In this module, seawater is pumped into the recuperator by a seawater pump, preheated by the high-temperature water vapor conveyed by the flash tank, and then flows into the solar collector 23; the solar collector 23 uses the heat of solar energy to heat the seawater, and the heated seawater flows into the flash tank; in the flash tank, due to the pressure reduction, the hot water quickly evaporates to generate water vapor; the water vapor enters the recuperator, and in the recuperator, the high-temperature water vapor heats the incoming seawater for heat recovery, and at the same time its liquefaction releases heat to form fresh water; the fresh water cooled by the recuperator finally flows into the fresh water tank 26 and is stored. The above-mentioned fresh water preparation path can be defined as the first fresh water preparation path of the present invention.

[0058] In the SOEC mode, the fresh water prepared by the fresh water preparation module 2 is transported to the hydrogen transportation module 5 for preheating and then supplied to the rSOC module 1; in the SOFC mode, it receives the fresh water as the reaction product of the hydrogen-oxygen fuel cell from the hydrogen transportation module 5 for storage.

[0059] Furthermore, the fresh water preparation module 2 is a two-stage flash evaporation device driven by solar heat, and its regenerator adopts a two-stage structure, namely, regenerator 1 21 and regenerator 2 22. At the same time, the flash tank can also adopt a two-stage structure, namely, flash tank 1 25 and flash tank 2 24. Flash tank 1 25 is connected to regenerator 1 21, flash tank 24 is connected to regenerator 2 22, solar collector 23 supplies energy to flash tank 2 24 and flash tank 1 25, and regenerator 2 22 is connected to solar collector 23 to form a loop. This part of the structure is a relatively mature technology for producing fresh water from solar energy, which will not be repeated here. The system's fresh water is mainly provided by a two-stage flash evaporation device driven by solar energy. In the SOFC mode, the hydrogen and oxygen fuel cell reaction will produce a large amount of fresh water, which will jointly supply the fresh water demand of the island artificial base, and the supply is sufficient.

[0060] The renewable energy sources that can be utilized by the wind, light, and wave energy power generation module 3 of the present invention include solar energy, wind energy, and wave energy, that is, it can include a solar power generation device 31, a wind power generation device 32, and a wave power generation device 33. The three renewable energy power generation devices jointly generate electricity, and use a DC / AC inverter 34 for AC / DC conversion. The wind power generation device uses small and medium-sized horizontal axis wind turbines or vertical axis wind turbines according to the wind speed characteristics of the island, and uses a permanent magnet synchronous motor for wind power generation. The generated AC power is converted into usable power through rectification-inversion; the photovoltaic power generation device uses high-efficiency monocrystalline silicon to improve the efficiency of light energy conversion; the wave power generation device uses a point absorption wave energy generator to adapt to the island wave conditions, and the generated AC power is converted into usable power through the rectification-inversion process. In the SOEC mode, it supplies power to the artificial base and to the rSOC for electrolysis of seawater to produce hydrogen; in the SOFC mode, it supplies power to the artificial base together with the rSOC module 1. For example, by selecting a typical day to calculate the output characteristics of photovoltaic, wind and wave power generation, photovoltaic power generation is concentrated in the period of strong solar radiation, wind power generation has large fluctuations, and wave power generation is relatively stable and periodic. The three renewable energy power generation devices are coupled to generate electricity to compensate for the volatility of single renewable energy power generation.

[0061] Combined with wind, light and wave power generation module 3, the rSOC is used to absorb the island's renewable energy to achieve electricity-to-hydrogen energy storage, and the hydrogen storage power generation is used to suppress the unstable output of wind, light and ocean energy, thus achieving zero-carbon energy supply on the island. The renewable energy multi-energy complementary power generation technology is adopted to overcome the problems of poor power output stability and insufficient supply caused by single operation.

[0062] In the SOEC mode, the wind, solar and wave energy generation modules 3 have sufficient power to supply power to the artificial base on the island to meet the needs of the artificial base, and at the same time supply power to the rSOC module 1 for the electrolysis of water to produce hydrogen.

[0063] In the SOFC mode, the power generated by the wind, solar, and wave energy power generation module 3 is insufficient, and the rSOC module 1 is needed to supplement power generation. The power generated by the renewable energy and the rSOC module 1 together meet the electrical load requirements of the artificial island base.

[0064] The air delivery module 4 of the present invention includes a fan 41 and an air preheater 42. The fan 41 collects air and provides power, and the air preheater 42 preliminarily preheats the air before use, because preventing the air with too low temperature from entering the rSOC module 1 may cause unstable reactions. Specifically:

[0065] In the SOFC mode, air is delivered to the fuel electrode of the rSOC module 1 through the fan 41 and the air preheater 42 to take away the reaction heat and provide the oxygen required for the electrochemical reaction.

[0066] The hydrogen delivery module 5 of the present invention mainly includes a steam preheater 51, a condenser 52, a hydrogen storage tank 53, a fuel preheater 54, and a compressor 55. The steam preheater 51 and the condenser 52 are mainly used in the SOEC mode, the fuel preheater 54 and the compressor 55 are mainly used in the SOFC mode, and the hydrogen storage tank 53 is required in both modes. Specifically:

[0067] In the SOEC mode, the steam preheater 51 receives the fresh water from the fresh water preparation module 2 and the hydrogen produced by the electrolytic water hydrogen production reaction. In the steam preheater 51, the fresh water and the hydrogen exchange heat. The preheated fresh water is sent to the rSOC module 1 as the raw material for the electrolytic water hydrogen production reaction, and the hydrogen after temperature reduction is further cooled by the condenser 52 and then stored in the hydrogen storage tank 53, and the waste heat can be used by the artificial island base.

[0068] In the SOFC mode, the fuel preheater 54 receives the fresh water produced by the electrochemical reaction, and the hydrogen stored in the hydrogen storage tank 63 is also sent to the fuel preheater 54 through the compressor 55. In the fuel preheater 54, the fresh water and the hydrogen exchange heat. The preheated hydrogen is sent to the rSOC module 1 as the raw material for the electrochemical reaction, and the fresh water after temperature reduction is stored, and the waste heat can be used by the artificial island base.

[0069] Further, the afterburner 12, the fuel preheater 54, and the fresh water tank 26 of the present invention can be defined as the second fresh water preparation path. The complete path of fresh water preparation can be described as: in the SOFC mode, the rSOC module 1 generates electricity as a hydrogen-oxygen fuel cell. The high-temperature tail gas at the fuel electrode outlet still contains some unreacted hydrogen, which is completely burned together with the remaining air at the air electrode outlet in the afterburner 12 to further increase the tail gas temperature; the high-temperature water vapor and air mixture first preheats the inlet hydrogen, the water vapor liquefies and releases heat to become fresh water and enters the fresh water tank 26 in the fresh water preparation module 2 for storage, and the high-temperature flue gas provides heat energy for the artificial island base.

[0070] The system scheduling module 6 of the present invention suppresses the random uncertainty of the output of renewable energy through multi-energy complementarity and flexible switching of operating strategies, improving the source-load matching and the system's ability to accommodate distributed renewable energy.

[0071] In the embodiment of the present invention, the power generation output characteristics of different types of renewable energy are calculated for a typical day, as shown in Figure 4 . The photovoltaic power generation is concentrated in the periods with strong solar radiation, the wind power generation has large fluctuations, and the wave power generation is relatively stable and periodic.

[0072] By matching the total power generation of renewable energy with the electrical load of the island artificial base, the all-day strategy is formulated according to the surplus or shortage of the power generation of renewable energy.

[0073] In the scenario of having surplus renewable power, the renewable power is converted into hydrogen for storage through the SOEC mode.

[0074] In the scenario of insufficient renewable power, the SOFC mode is adopted to supplement the power supply for the artificial base with the stored hydrogen as fuel, thus achieving all-weather energy self-consistency and having a strong energy guarantee ability.

[0075] The calculation results of the system simulation operation are as shown in Figure 6 and Figure 7 . The comprehensive energy utilization efficiency of the system is as high as 94.39%, the hydrogen production capacity can reach 3.46 kg / h, the fresh water production capacity can reach 15.4 kg / h, and the waste heat production capacity can reach 36.47 kW. Due to the large amount of water generated by the hydrogen-oxygen fuel cell reaction, the fresh water production in the SOFC mode is significantly higher than that in the SOEC mode.

[0076] Traditional thermal power plants are limited by the Carnot cycle, and the combined heat and power generation efficiency is about 70%. In contrast, the present system significantly reduces energy consumption by greatly improving the energy efficiency, having an obvious energy-saving effect.

[0077] In the embodiment of the present invention, three types of renewable energy, namely solar energy, wind energy, and wave energy, are used for energy supply, and the core energy conversion device rSOC only involves the conversion of electricity, hydrogen, and water. There is no carbon emission throughout the system operation process, realizing zero-carbon energy supply for the island and having a significant emission reduction effect.

[0078] In the embodiment of the present invention, the fresh water is mainly provided by the solar-driven two-stage flash evaporation device. The water vapor that is not completely electrolyzed in the SOEC mode is also condensed into fresh water, and a large amount of fresh water is generated by the hydrogen-oxygen fuel cell reaction in the SOFC mode. These three jointly supply the fresh water demand of the island artificial base, and the supply is sufficient.

[0079] The island electricity-hydrogen-water-heat combined supply system and operation method driven by wind-solar-wave energy provided by the embodiments of the present invention have the following advantages: First, in the island electricity-hydrogen-water-heat system of the present invention, the rSOC can not only be used as an energy storage device but also as a supplementary power generation device, realizing two functions on the same device. Compared with the traditional island energy system that uses diesel generators for supplementary power generation and batteries for energy storage, this system has greater superiority. Second, the island electricity-hydrogen-water-heat system of the present invention can not only supply electricity and fresh water, but also achieve internal heat self-consistency by making full use of the waste heat in the system. Third, the island electricity-hydrogen-water-heat system of the present invention is based on the matching of renewable energy power generation and the island artificial base, and formulates the all-day operation strategy according to the surplus or shortage of renewable electricity. The comprehensive energy efficiency and output of the system are very remarkable.

[0080] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other. The key points of each embodiment are the differences from other embodiments.

[0081] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A combined power, hydrogen, water and heat supply system for islands driven by wind, light and wave energy, characterized in that Comprising: Module (1), having two operating modes of SOEC and SOFC; in the SOEC mode, it receives the surplus renewable energy power from the wind, light, and wave energy power generation module (3) and the fresh water from the fresh water preparation module (2), and undergoes an electrolytic water hydrogen production reaction; in the SOFC mode, it receives the air from the air delivery module (4) and the hydrogen from the hydrogen delivery module (5) to carry out an electrochemical reaction for power generation; the generated power is delivered to the system dispatching module (6); Fresh water preparation module (2), adopting solar thermal-driven two-stage flash evaporation technology to produce fresh water from seawater for use in the island artificial base (61); Wind, light, and wave energy power generation module (3), generating electricity based on three renewable energy sources of wind energy, light energy, and wave energy, and supplying it to the island artificial base (61) to meet its electricity demand; Air delivery module (4), providing the oxygen required for the electrochemical reaction in the SOFC mode, and at the same time receiving the remaining air that has not reacted in the rSOC module (1) to preheat the air, and after preheating, delivering the remaining air to the burner in the rSOC module (1) for combustion; Hydrogen delivery module (5), storing the hydrogen generated when the rSOC module (1) operates in the SOEC mode, and providing the hydrogen required when the rSOC module (1) operates in the SOFC mode; System dispatching module (6), based on the electricity demand of the island artificial base (61) and the output characteristics of wind energy, solar energy, and wave energy power generation, performs hourly quantitative matching of the renewable energy supply power and the electricity demand, and accordingly controls the switching of the rSOC module (1) to operate in the SOEC or SOFC mode.

2. The integrated power, hydrogen, water and heat supply system for islands driven by wind and light energy and wave energy according to claim 1, wherein The said rSOC module (1), in the SOEC mode, water vapor undergoes an electrolytic reaction at the fuel electrode to generate hydrogen, oxygen ions pass through the electrolyte to reach the air electrode to generate oxygen, the product at the air electrode is used to preheat the inlet air, the mixture of hydrogen and water vapor produced at the fuel electrode is first used to preheat the inlet fresh water, and then separated, the hydrogen is stored, and its high-temperature waste heat is used for the island artificial base; In the SOFC mode, hydrogen and air are respectively pressurized and preheated, and then introduced into the fuel electrode and the air electrode to carry out an electrochemical reaction, directly converting the stored chemical energy into electrical energy, and jointly meeting the electricity demand of the island artificial base with the renewable electricity.

3. The integrated power, hydrogen, water, and heat supply system for islands driven by wind, light, and wave energy according to claim 1, wherein The said fresh water preparation module (2) is a solar thermal-driven two-stage flash evaporation device; first, seawater is pumped into the regenerator one (21) and the regenerator two (22) for preheating, and after preheating, it enters the solar collector (23), the solar collector (23) converts solar radiation into heat energy to heat the seawater, the heated seawater enters the first-stage flash evaporation tank (24), part of the seawater quickly evaporates into water vapor, the water vapor enters the regenerator two (22) and then condenses and releases heat to become fresh water and enters the fresh water tank (26) for storage, another part of the seawater continues to enter the second-stage flash evaporation tank (25), part of the seawater quickly evaporates into water vapor, the water vapor enters the regenerator one (21) and then condenses and releases heat to become fresh water and enters the fresh water tank (26) for storage, after the two-stage flash evaporation is completed, the concentrated brine is discharged into the sea; In the SOEC mode, the prepared fresh water is transported to the hydrogen transportation module (5), preheated, and then supplied to the rSOC module (1) as a raw material for the hydrogen production reaction by electrolyzing water; in the SOFC mode, the fresh water, which is the product of the fuel cell electrochemical reaction of the rSOC module (1), is received and stored.

4. The integrated power, hydrogen, water, and heat supply system for islands driven by wind, light, and wave energy according to claim 1, wherein, The renewable energy utilized by the wind, light, and wave energy power generation module (3) includes one or several of solar energy (31), wind energy (32), and wave energy (33), and a DC / AC inverter (34) is used for AC-DC conversion; among them, according to the wind speed characteristics of the island, the wind power generation system adopts a small or medium-sized horizontal axis wind turbine or a vertical axis wind turbine, and a permanent magnet synchronous motor is used for wind power generation. The generated alternating current is converted into available power through rectification-inversion; the photovoltaic power generation system uses high-efficiency monocrystalline silicon to improve the light energy conversion efficiency; the wave energy power generation system uses a point absorption wave energy generator to adapt to the wave conditions of the island, and the generated alternating current is converted into available power through the rectification-inversion process. In the SOEC mode, the wind, light, and wave energy power generation module (3) transports power to meet the electricity demand of the island artificial base, and at the same time transports power to the rSOC module (1) for the hydrogen production reaction by electrolyzing water; in the SOFC mode, the renewable energy power and the power generation of the rSOC module (1) jointly meet the electricity load demand of the island artificial base.

5. The island electricity-hydrogen-water-heat combined supply system driven by wind-solar-wave energy according to claim 1, characterized in that, The air transportation module (4), in the SOFC mode, supplies air to the air electrode of the rSOC module (1) through a fan (41) to provide oxygen required for the electrochemical reaction, and at the same time receives the unreacted air at the outlet of the air electrode of the rSOC module (1) and preheats the air in the air preheater (42); after preheating, the remaining unreacted air at the outlet of the air electrode is transported to the afterburner (12) of the rSOC module (1) for complete combustion.

6. The integrated power, hydrogen, water and heat supply system for islands driven by wind-solar-wave energy according to claim 1, wherein The hydrogen transportation module (5), in the SOEC mode, receives the fresh water from the fresh water preparation module (2), is preheated, and then transported to the fuel electrode of the rSOC module (1) as a raw material for the hydrogen production reaction by electrolyzing water; receives the mixture of hydrogen and water vapor at the outlet of the fuel electrode of the rSOC module (1), and the mixture preheats the fresh water in the water vapor preheater (54), and then enters the condenser (52) after preheating; the hydrogen cools down in the condenser (52) and is finally stored in the hydrogen storage tank (53), and the water vapor condenses and releases heat in the condenser (52) to become liquid water, which is transported to the fresh water preparation module (2) for storage; receives the oxygen generated at the air electrode of the rSOC module (1), and the oxygen is transported to the system scheduling module (6) after preheating the fresh water in the water vapor preheater (51). In the SOFC mode, hydrogen is sent into the fuel preheater (55) through a compressor and then transported to the air electrode of the rSOC module (1) as a raw material for the electrochemical reaction after being preheated. At the same time, it receives the mixture of high-temperature flue gas and water vapor at the outlet of the afterburner (12) in the rSOC module (1). The mixture preheats hydrogen in the fuel preheater (54). The water vapor condenses and releases heat to become liquid water, which is transported to the fresh water preparation module (2) for storage. The high-temperature flue gas is transported to the system scheduling module (6) to provide heat for the island artificial base (61).

7. The island electricity-hydrogen-water-heat combined supply system driven by wind-solar-wave energy according to claim 1, wherein The rules for the system scheduling module (6) to control and switch between the two operating modes are as follows: when the electricity demand of the island artificial base (61) is less than the renewable energy power generation, the SOEC mode is adopted to convert the surplus renewable power into hydrogen for storage; when the electricity demand of the island artificial base (61) is greater than the renewable energy power generation, the SOFC mode is adopted, and the stored hydrogen is used as fuel to supplement the power supply for the artificial base, so as to suppress the output fluctuations of renewable energy such as wind, light, and wave energy and achieve all-weather energy self-consistency.

8. The operation method of the island electricity-hydrogen-water-heat combined supply system driven by wind, light, and wave energy according to claim 1, comprising: Producing and supplying fresh water to the island artificial base based on the fresh water preparation module; Monitoring the electrical load of the island artificial base and the renewable energy power generation. When the electrical load of the island artificial base is less than the renewable energy power generation, the SOEC mode is adopted, and the rSOC module uses renewable power and fresh water for electrolytic hydrogen production and energy storage; when the electrical load of the island artificial base is greater than the renewable energy power generation, the SOFC mode is adopted, and the stored hydrogen is used as fuel for the electrochemical reaction to generate electricity to supplement the power supply for the island artificial base, so as to achieve all-weather energy self-consistency.

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