Water photovoltaic hydrogen production and hydrogen storage island and control method

Abstract

The application provides an overwater photovoltaic hydrogen production and hydrogen storage island and a control method. The overwater photovoltaic hydrogen production, hydrogen production, underwater energy storage and power generation caisson energy storage and power generation are fused with each other, the characteristics and advantages are fully tapped, the characteristics and functions are utilized with each other, the components are reused, and the problems existing in the land hydrogen production are solved. The control method considers the photovoltaic power generation characteristics, fully utilizes the water pump / water turbine integrated machine of the underwater energy storage and power generation caisson to regulate and control the variable frequency water pump flow change and the water turbine power generation output power change, adapts to the maximum power output of the photovoltaic square array, and realizes efficient water electrolysis hydrogen production.

Description

Technical Field

[0001] This invention relates to the field of new energy power generation, specifically to a floating photovoltaic electrochemical hydrogen production and storage island and its control method. Background Technology

[0002] Renewable energy is one of the most important available energy sources and a crucial factor in accelerating the improvement of hydrogen production conversion efficiency and the scale of single-unit hydrogen production. Currently, terrestrial hydrogen production is widely used in the hydrogen production industry, but it faces the following problems: power resources: hydrogen production is a major electricity consumer, occupying a significant portion of the power grid; safety considerations require a relatively large land area; and pressurized hydrogen storage containers require considerable space for safety and reliability. Therefore, there is an urgent need to develop a hydrogen production system and method that avoids consuming large amounts of land, power grid, and human resources. Summary of the Invention

[0003] To address the aforementioned technical issues, this invention proposes a floating photovoltaic-electrochemical hydrogen production and storage island and its control method. Utilizing the advantages of large water bodies with their depth, pressure, constant temperature, open water area, unobstructed sunlight, and water source, it integrates floating photovoltaic, hydrogen production, underwater energy storage and power generation, and caisson energy storage and power generation, fully leveraging their respective characteristics and advantages. The characteristics and functions are mutually utilized, and components are reused.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A floating photovoltaic electrochemical hydrogen production and storage island includes a photovoltaic array, a gas storage pontoon, a photovoltaic support pontoon, a water electrolysis hydrogen production chamber, and an underwater energy storage and power generation caisson. The photovoltaic array consists of several photovoltaic strings, each of which is a rectangular structure. Photovoltaic support floats are installed at the four corners of the photovoltaic strings, and gas storage floats are evenly distributed on one of the photovoltaic strings at the edge of the photovoltaic array, floating on the water surface to support the photovoltaic strings. The underwater energy storage and power generation caisson is anchored to the bottom of the water body, and the water electrolysis hydrogen production chamber is fixedly installed on the top of the underwater energy storage and power generation caisson and placed in the water body; The photovoltaic array floats on the water body with the support of the gas storage float and the photovoltaic support float. It converts light energy into electrical energy, which is then used to provide power for hydrogen production by water electrolysis and the drainage energy storage of the underwater energy storage power generation caisson through power distribution and control equipment. The photovoltaic support float includes a float, a support, and a combiner box. It has a cylindrical upper section and a conical sealed lower section. The support is placed on the float, and the combiner box is installed in the support. The photovoltaic power generation is output to the power distribution and control equipment through the combiner box. The gas storage floats include hydrogen storage floats, compressed hydrogen floats, oxygen storage floats, and compressed oxygen floats; The aforementioned water electrolysis hydrogen production chamber includes a water electrolysis hydrogen production chamber body, water electrolysis hydrogen production equipment, reverse osmosis seawater desalination or water filtration device, power distribution and control equipment, hydrogen delivery pipeline and oxygen delivery pipeline.

[0005] Furthermore, the hydrogen storage float, compressed hydrogen float, oxygen storage float, and compressed oxygen float are all cylindrical rigid structures, installed on the four sides of a photovoltaic string in the photovoltaic array; the hydrogen storage float, compressed hydrogen float, oxygen storage float, and compressed oxygen float are all connected to the photovoltaic string through installed brackets, floating on the water surface to support the photovoltaic string; the compressed hydrogen float is equipped with a compressed hydrogen outlet, and the compressed oxygen float is equipped with a compressed oxygen outlet.

[0006] Furthermore, the bottom of the hydrogen storage float is equipped with a hydrogen inlet and outlet pipe, which is connected to the inside of the hydrogen storage float. The other end of the hydrogen inlet and outlet pipe is connected to the hydrogen inlet and outlet compressed gas pipe through a hydrogen check valve, and is connected to the hydrogen outlet of the hydrogen production chamber through the water electrolysis chamber, so as to store the hydrogen produced by the water electrolysis in the hydrogen storage float. The oxygen storage float is equipped with an oxygen inlet and outlet pipe at the bottom, which is connected to the inside of the oxygen storage float. The other end of the oxygen inlet and outlet pipe is connected to the oxygen inlet and outlet compressed gas pipe through an oxygen check valve, and is connected to the hydrogen production port of the water electrolysis chamber through the water electrolysis hydrogen production port, so that the oxygen produced by the water electrolysis is stored in the oxygen storage float.

[0007] Furthermore, a compressed hydrogen outlet is installed on the upper side of the compressed hydrogen float. The compressed hydrogen float is connected to the inlet and outlet compressed hydrogen gas pipeline at the bottom through a compressed hydrogen check valve and is connected to the inside of the compressed hydrogen float. The other end of the inlet and outlet compressed hydrogen gas pipeline is placed on the upper part of the hydrogen underwater energy storage and power generation tank and is connected to the inside, so that the compressed hydrogen generated during the power generation process of the hydrogen underwater energy storage and power generation tank is stored in the compressed hydrogen float. The compressed oxygen pontoon is equipped with a compressed oxygen gas outlet on one side of its upper part. At the bottom of the compressed oxygen pontoon, it is connected to the oxygen inlet and outlet compressed gas pipeline through a compressed oxygen check valve and communicates with the inside of the compressed oxygen pontoon. The other end of the oxygen inlet and outlet compressed gas pipeline is placed on the upper part of the oxygen underwater energy storage and power generation caisson and communicates with the inside, so that the compressed oxygen generated during the power generation process of the oxygen underwater energy storage and power generation caisson is stored in the compressed oxygen pontoon.

[0008] Furthermore, the water electrolysis hydrogen production equipment and the power distribution and control equipment are distributed and fixedly installed at the bottom of the water electrolysis hydrogen production chamber. The hydrogen production port of the water electrolysis hydrogen production equipment is connected to the hydrogen inlet and outlet pipes, and the other end of the hydrogen outlet pipe is connected to the inside of the hydrogen storage float. The hydrogen produced by the water electrolysis hydrogen production equipment is discharged into the hydrogen storage float through the hydrogen outlet pipe. The oxygen production port of the water electrolysis hydrogen production equipment is connected to the oxygen inlet and outlet pipes, and the other end of the oxygen inlet and outlet pipes is connected to the inside of the oxygen storage float. The oxygen produced by the water electrolysis hydrogen production equipment is discharged into the oxygen storage float through the hydrogen outlet pipe.

[0009] Furthermore, the power distribution and control equipment is connected to the combiner box and the power supply systems for the hydrogen underwater energy storage power generation caisson and the oxygen underwater energy storage power generation caisson via cables. The turbine power generation of the integrated pump / turbine unit in the hydrogen underwater energy storage power generation caisson, the turbine power generation of the integrated pump / turbine unit in the oxygen underwater energy storage power generation caisson, and the photovoltaic array provide power to the water electrolysis hydrogen production equipment. By controlling the pumps of the integrated pumps in the hydrogen underwater energy storage power generation caisson and the integrated pumps in the oxygen underwater energy storage power generation caisson, water is pumped into the corresponding underwater energy storage power generation caisson for energy storage, ensuring the stability of the power supply for water electrolysis hydrogen production.

[0010] Furthermore, the reverse osmosis seawater desalination or water filtration device is embedded in the water electrolysis hydrogen production chamber. One end of the reverse osmosis seawater desalination or water filtration device passes through the water electrolysis hydrogen production chamber and is connected to the fresh water input end, while the other end is connected to the water body. The reverse osmosis seawater desalination or water filtration device uses the pressure difference between the depth pressure of the water body and the pressure at the fresh water input end of the water electrolysis hydrogen production equipment to provide fresh water to the water electrolysis hydrogen production equipment.

[0011] Furthermore, the underwater energy storage and power generation caisson includes a hydrogen underwater energy storage and power generation caisson and an oxygen underwater energy storage and power generation caisson. The hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson can be cuboid or tank-shaped structures, connected to each other, and placed in the lower part of the water electrolysis hydrogen production chamber, at the bottom of the water body. The hydrogen underwater energy storage and power generation caisson is equipped with an integrated hydrogen underwater energy storage and power generation caisson water pump / turbine and hydrogen inlet and outlet compressed gas pipelines; the oxygen underwater energy storage and power generation caisson is equipped with an integrated oxygen underwater energy storage and power generation caisson water pump / turbine and oxygen inlet and outlet compressed gas pipelines; the integrated hydrogen underwater energy storage and power generation caisson water pump / turbine is embedded in the hydrogen underwater energy storage and power generation caisson near the bottom, one end of the integrated hydrogen underwater energy storage and power generation caisson water pump / turbine is connected to the inside of the hydrogen underwater energy storage and power generation caisson, and the other end of the integrated hydrogen underwater energy storage and power generation caisson water pump / turbine is placed in the water body; The integrated pump / turbine unit for underwater energy storage and power generation is embedded and installed near the bottom of the underwater energy storage and power generation caisson. One end of the integrated pump / turbine unit is connected to the inside of the underwater energy storage and power generation caisson, while the other end of the pump / turbine unit is placed in the water. The hydrogen underwater energy storage and power generation caisson water pump / turbine integrated unit and the oxygen underwater energy storage and power generation caisson water pump / turbine integrated unit are respectively an adjustable flow rate variable frequency water pump and a controllable output power water turbine; One end of the hydrogen inlet and outlet compressed gas pipeline is installed through the top of the hydrogen underwater energy storage and power generation tank and is connected to the gas inside the hydrogen underwater energy storage and power generation tank. The other end of the hydrogen inlet and outlet compressed gas pipeline is connected to the compressed hydrogen float through a compressed hydrogen check valve and to the hydrogen inlet and outlet pipeline through a hydrogen check valve. One end of the oxygen inlet and outlet compressed gas pipeline is installed through the top of the oxygen underwater energy storage and power generation caisson and is connected to the gas inside the oxygen underwater energy storage and power generation caisson. The other end of the oxygen inlet and outlet compressed gas pipeline is connected to the compressed oxygen float through a compressed oxygen check valve and to the oxygen inlet and outlet compressed gas pipeline through an oxygen check valve.

[0012] This invention also provides a control method for a hydrogen production and storage island for hydroelectric photovoltaic power generation, comprising the following steps: Step (1) In order to ensure the optimization of hydrogen production in the hydrogen storage island of the floating photovoltaic and electrochemical hydrogen production, and at the same time reduce the buoyancy balance of the hydrogen underwater energy storage power generation caisson and the oxygen underwater energy storage power generation caisson, the principle of local consumption of photovoltaic power generation is adopted, and the optimization control rules are formulated based on the water level in the hydrogen underwater energy storage power generation caisson and the oxygen underwater energy storage power generation caisson. Step (2) When the maximum output power of photovoltaic power generation meets the hydrogen production power of water electrolysis, control the photovoltaic power generation to supply hydrogen to the hydrogen electrolysis equipment through power distribution and control equipment, and the generated hydrogen and oxygen enter the hydrogen storage float and oxygen storage float respectively. Step (3) When the photovoltaic power generation is greater than the hydrogen production power of water electrolysis, the excess power of the photovoltaic power generation is absorbed by the variable frequency water pump of the hydrogen or oxygen underwater energy storage power generation caisson; according to the power of the water electrolysis hydrogen production equipment, the power range of the variable frequency water pump of the underwater energy storage power generation caisson and the output power range of the water turbine, the irradiance, the characteristics of the photovoltaic module and the rated power of the photovoltaic array, combined with the photovoltaic cell IV curve lookup table and calculation analysis, the drainage power of the variable frequency water pump of the underwater energy storage power generation caisson is determined to ensure the maximum power output of the photovoltaic and realize the best efficiency of the photovoltaic array to produce hydrogen; the generated hydrogen and oxygen enter the hydrogen storage float and the oxygen storage float respectively; at the same time, the variable frequency water pump of the hydrogen or oxygen underwater energy storage power generation caisson is started to drain the energy storage, and the water inside the hydrogen or oxygen underwater energy storage power generation caisson is discharged. The gas stored in the hydrogen or oxygen float is sucked into the hydrogen or oxygen underwater energy storage power generation caisson through the hydrogen or oxygen inlet and outlet pipes, hydrogen check valve or oxygen check valve; Step (4) When the photovoltaic power generation is less than the hydrogen production power of water electrolysis, the hydrogen production power of water electrolysis is supplemented by the water turbine power generation of the hydrogen underwater energy storage power generation caisson or the oxygen underwater energy storage power generation caisson; the water turbine of the integrated water pump / water turbine is controlled to drive the power generation by the seawater head pressure, and the seawater is discharged into the hydrogen or oxygen underwater energy storage power generation caisson. At this time, the water turbine power generation and photovoltaic power generation are under the control of the power distribution and control equipment to supplement the photovoltaic power generation to supply power to the electrolysis equipment for hydrogen production; when the pressure in the hydrogen or oxygen underwater energy storage power generation caisson is greater than the pressure of the compressed hydrogen storage or compressed oxygen storage float, the hydrogen or oxygen compressed gas is compressed into the hydrogen or oxygen compressed gas chamber for storage through the hydrogen or oxygen inlet and outlet pipelines and the compressed hydrogen or compressed oxygen check valve.

[0013] Further, step (1) includes: 1) During the process of using a variable frequency water pump to drain water and store energy during the photovoltaic power generation hydrogen production and waste electricity production: a. When the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson are equal, the variable frequency water pump of the hydrogen underwater energy storage and power generation caisson should be controlled first to drain and store energy. b. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is greater than or equal to the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the drainage flow rate of the variable frequency water pump in the underwater energy storage and power generation caisson with the higher water level is controlled according to the current photovoltaic irradiance and the photovoltaic cell IV curve, so as to realize the maximum power variable frequency water pump drainage energy storage of the photovoltaic array. c. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is less than the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the flow rate of the variable frequency pump in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson can be controlled in a time-sharing manner based on the current photovoltaic irradiance and the photovoltaic cell IV curve to ensure that the water level in either the hydrogen or oxygen underwater energy storage and power generation caisson is relatively balanced. 2) During the process of generating hydrogen from photovoltaic power generation, when the turbine is drawing water to generate electricity, the following occurs: a. When the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson are equal, the turbine output power of the hydrogen underwater energy storage and power generation caisson should be prioritized for water inflow and power generation based on the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve. b. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is less than the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the power generation power and flow rate of the turbine are controlled according to the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve. Under the condition of ensuring the maximum power output of the photovoltaic array, the turbine power generation of either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson is controlled in a time-sharing manner to ensure the relative balance of the water levels in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson. c. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is greater than or equal to the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the power generation power and flow rate of the underwater energy storage and power generation caisson at the low water level are controlled according to the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve.

[0014] Beneficial effects:

[0015] (1) Avoid occupying a large amount of land, power grid, and human resources; (2) The functions of the floating photovoltaic power generation device, hydrogen production equipment, and underwater energy storage power generation caisson are integrated, and the components are reused: Water body and head pressure provide the pressure for reverse osmosis membrane seawater desalination or water filtration; the floating pontoon of the floating photovoltaic power generation provides storage space for hydrogen, oxygen gas and compressed gas; the underwater energy storage and power generation caisson stores energy and generates electricity to provide a stable power source for hydrogen production through water electrolysis, while simultaneously compressing hydrogen and oxygen, similar to the principle of an air pump; the weight of the hydrogen production equipment and the power distribution and control equipment serves as the system counterweight, reducing the anchoring tension of the underwater energy storage and power generation caisson; (3) The hydrogen production equipment is submerged in water: it is temperature-controlled and safe, and can avoid disasters that occur on land; (4) Unmanned, low cost, mature related technologies, and strong operability. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0017] Figure 1 This is a schematic diagram of a hydroelectric hydrogen production and storage island system based on the present invention. Figure 2 This is a structural diagram of a hydrogen production and storage island for hydroelectric power generation in water, according to the present invention. Figure 3 This is a flowchart illustrating the workflow of a hydroelectric hydrogen production and storage island based on the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0019] like Figure 1 , Figure 2 As shown, a floating photovoltaic electrochemical hydrogen production and storage island of the present invention includes a photovoltaic array, a gas storage float, a photovoltaic support float 2, an electrolytic water hydrogen production chamber 3, and an underwater energy storage and power generation caisson.

[0020] The photovoltaic array consists of several photovoltaic strings 1, each of which is a rectangular structure. Photovoltaic support floats 2 are installed at the four corners of the photovoltaic strings 1. Gas storage floats are evenly distributed on one of the photovoltaic strings 1 at the edge of the photovoltaic array and float on the water to support the photovoltaic strings 1.

[0021] The underwater energy storage and power generation caisson is anchored at the bottom of the water body, and the water electrolysis hydrogen production chamber 3 is fixedly installed on top of the underwater energy storage and power generation caisson and placed in the water body.

[0022] The photovoltaic array floats on the water under the support of the gas storage pontoon and the photovoltaic support pontoon 2. It converts light energy into electrical energy, which is then used by the power distribution and control equipment 8 to provide power for hydrogen production by water electrolysis and the drainage energy storage of the underwater energy storage power generation caisson.

[0023] The photovoltaic support float 2 includes a float, a support 9, and a combiner box 30. It has a cylindrical upper section and a conical, sealed lower section. The support 9 is placed on top of the float, and the combiner box 30 is installed inside the support 9. Photovoltaic power generation is output to the power distribution and control equipment 8 via the combiner box.

[0024] The gas storage floats include: hydrogen storage float 4, compressed hydrogen float 5, oxygen storage float 6 and compressed oxygen float 7; Among them, the hydrogen storage float 4, compressed hydrogen float 5, oxygen storage float 6, and compressed oxygen float 7 are all cylindrical rigid structures, installed on the four sides of a photovoltaic string 1 of the photovoltaic array. All four floats are connected to the photovoltaic string 1 via mounting brackets 9, floating on the water surface to support the photovoltaic string 1. Compressed hydrogen float 5 is equipped with a compressed hydrogen outlet 10, and compressed oxygen float 7 is equipped with a compressed oxygen outlet 11.

[0025] The bottom of the hydrogen storage float 4 is equipped with a hydrogen inlet / outlet pipe 12, which is connected to the interior of the hydrogen storage float 4. The other end of the hydrogen inlet / outlet pipe 12 is connected to the hydrogen inlet / outlet compressed gas pipe 14 via a hydrogen check valve 13, and also passes through the water electrolysis hydrogen production chamber 3 and is connected to the hydrogen outlet 15 of the water electrolysis hydrogen production chamber, storing the hydrogen produced by water electrolysis in the hydrogen storage float 4. Similarly, the bottom of the oxygen storage float 6 is equipped with an oxygen inlet / outlet pipe 16, which is connected to the interior of the oxygen storage float 6. The other end of the oxygen inlet / outlet pipe 16 is connected to the oxygen inlet / outlet compressed gas pipe 18 via an oxygen check valve 17, and also passes through the water electrolysis hydrogen production chamber 3 and is connected to the water electrolysis hydrogen production oxygen outlet 19, storing the oxygen produced by water electrolysis in the oxygen storage float 6.

[0026] A compressed hydrogen outlet 10 is installed on the upper side of the compressed hydrogen float 5. The bottom of the compressed hydrogen float 5 is connected to the hydrogen inlet / outlet compressed gas pipeline 14 via a compressed hydrogen check valve 20 and is connected to the interior of the compressed hydrogen float 5. The other end of the hydrogen inlet / outlet compressed gas pipeline 14 is placed on the upper part of the hydrogen underwater energy storage and power generation tank 21 and is connected to the interior, storing the compressed hydrogen during the power generation process of the hydrogen underwater energy storage and power generation tank 21 in the compressed hydrogen float 5. Similarly, a compressed oxygen outlet 11 is installed on the upper side of the compressed oxygen float 7. The bottom of the compressed oxygen float 7 is connected to the oxygen inlet / outlet compressed gas pipeline 18 via a compressed oxygen check valve 22 and is connected to the interior of the compressed oxygen float 7. The other end of the oxygen inlet / outlet compressed gas pipeline 18 is placed on the upper part of the oxygen underwater energy storage and power generation tank 22 and is connected to the interior, storing the compressed oxygen during the power generation process of the oxygen underwater energy storage and power generation tank 22 in the compressed oxygen float 7. The electrolytic water hydrogen production chamber 3 includes an electrolytic water hydrogen production chamber body 23, an electrolytic water hydrogen production equipment 24, a reverse osmosis seawater desalination or water filtration device 25, power distribution and control equipment 8, a hydrogen delivery pipeline, and an oxygen delivery pipeline.

[0027] The water electrolysis hydrogen production equipment 24 and the power distribution and control equipment 8 are fixedly installed at the bottom of the water electrolysis hydrogen production chamber 23. The hydrogen production port 15 of the water electrolysis hydrogen production equipment is connected to the hydrogen inlet and outlet pipe 12. The other end of the hydrogen outlet pipe 12 is connected to the inside of the hydrogen storage float 4. The hydrogen produced by the water electrolysis hydrogen production equipment 24 is discharged into the hydrogen storage float 4 through the hydrogen outlet pipe 12.

[0028] Similarly, the oxygen production port of the water electrolysis hydrogen production equipment 24 is connected to the oxygen inlet and outlet pipe 16, and the other end of the oxygen inlet and outlet pipe 16 is connected to the inside of the oxygen storage float 6. The oxygen produced by the water electrolysis hydrogen production equipment 24 is discharged into the oxygen storage float 6 through the hydrogen outlet pipe 12.

[0029] The power distribution and control equipment 8 is connected to the power supply systems of the combiner box 30, the hydrogen underwater energy storage and power generation caisson 21, and the oxygen underwater energy storage and power generation caisson 22 via cables. The turbine power generation of the hydrogen underwater energy storage and power generation caisson water pump / turbine integrated machine 26, the turbine power generation of the oxygen underwater energy storage and power generation caisson water pump / turbine integrated machine 27, and the photovoltaic array provide power to the water electrolysis hydrogen production equipment 24. Similarly, by controlling the water pumps of the hydrogen underwater energy storage and power generation caisson water pump / turbine integrated machine 26 and the oxygen underwater energy storage and power generation caisson water pump / turbine integrated machine 27, water is pumped into the corresponding underwater energy storage and power generation caissons to store energy, ensuring the stability of the power supply for water electrolysis hydrogen production.

[0030] A reverse osmosis seawater desalination or water filtration device 25 is embedded in the water electrolysis hydrogen production chamber 23. One end of the reverse osmosis seawater desalination or water filtration device 25 passes through the water electrolysis hydrogen production chamber 23 and is connected to the freshwater input end 28, while the other end is connected to the water body. The working principle of the reverse osmosis seawater desalination or water filtration device 25 is to use the pressure difference between the depth pressure of the water body and the freshwater input end 28 of the water electrolysis hydrogen production device 24 to provide freshwater to the water electrolysis hydrogen production device 24.

[0031] The underwater energy storage and power generation caissons include a hydrogen underwater energy storage and power generation caisson 21 and an oxygen underwater energy storage and power generation caisson 22. The hydrogen underwater energy storage and power generation caisson 21 and the oxygen underwater energy storage and power generation caisson 22 can be cuboid or tank-shaped structures, interconnected, and placed below the water electrolysis hydrogen production chamber 23, at the bottom of the water body. The weight of the water electrolysis hydrogen production chamber 3 is reduced based on Archimedes' principle to decrease the buoyancy of the hydrogen underwater energy storage and power generation caisson 21 and the oxygen underwater energy storage and power generation caisson 22, thereby reducing the anchoring tension.

[0032] The hydrogen underwater energy storage and power generation caisson 21 is equipped with a hydrogen underwater energy storage and power generation caisson water pump / turbine integrated unit 26 and hydrogen inlet / outlet compressed gas pipeline 14. The oxygen underwater energy storage and power generation caisson 22 is equipped with an oxygen underwater energy storage and power generation caisson water pump / turbine integrated unit 27 and oxygen inlet / outlet compressed gas pipeline 18. Among them, the hydrogen underwater energy storage and power generation caisson water pump / turbine integrated unit 26 is embedded in the hydrogen underwater energy storage and power generation caisson 21 near the bottom. One end of the hydrogen underwater energy storage and power generation caisson water pump / turbine integrated unit 26 is connected to the interior of the hydrogen underwater energy storage and power generation caisson 21, and the other end of the hydrogen underwater energy storage and power generation caisson water pump / turbine integrated unit 26 is placed in the water.

[0033] Similarly, the integrated pump / turbine unit 27 for underwater energy storage and power generation is embedded in the underwater energy storage and power generation caisson 22 near the bottom. One end of the integrated pump / turbine unit 27 is connected to the inside of the underwater energy storage and power generation caisson 22, and the other end of the integrated pump / turbine unit 27 for inlet and outlet is placed in the water.

[0034] The hydrogen underwater energy storage and power generation caisson pump / turbine integrated unit 26 and the oxygen underwater energy storage and power generation caisson pump / turbine integrated unit 27 are respectively an adjustable flow rate variable frequency pump and a controllable output power turbine.

[0035] One end of the hydrogen inlet and outlet compressed gas pipeline 14 is installed through the top of the hydrogen underwater energy storage and power generation tank 21 and is connected to the gas inside the hydrogen underwater energy storage and power generation tank 21. The other end of the hydrogen inlet and outlet compressed gas pipeline 14 is connected to the compressed hydrogen float 5 through the compressed hydrogen check valve 20 and the hydrogen check valve 13 through the hydrogen inlet and outlet pipeline 12.

[0036] Similarly, one end of the oxygen inlet and outlet compressed gas pipeline 18 is installed through the top of the oxygen underwater energy storage and power generation caisson 22 and is connected to the gas inside the oxygen underwater energy storage and power generation caisson 22. The other end of the oxygen inlet and outlet compressed gas pipeline 18 is connected to the compressed oxygen float 7 through the compressed oxygen check valve 29 and to the oxygen inlet and outlet pipeline 16 through the oxygen check valve 17.

[0037] When the hydrogen underwater energy storage and power generation caisson 21 is storing energy, the water pump of the hydrogen underwater energy storage and power generation caisson water pump / hydro turbine integrated machine 26 is started to discharge the water inside the hydrogen underwater energy storage and power generation caisson 21. At the same time, the internal pressure of the hydrogen underwater energy storage and power generation caisson 21 is relatively reduced. At this time, the hydrogen inlet and outlet compressed gas pipeline 14 draws the gas stored in the hydrogen storage float 4 into the hydrogen underwater energy storage and power generation caisson 21 through the hydrogen check valve 13.

[0038] When the hydrogen underwater energy storage and power generation caisson 21 generates electricity, the turbine of the integrated pump / turbine unit 26 of the hydrogen underwater energy storage and power generation caisson is started. The turbine drives the water turbine to generate electricity through the water head pressure, and discharges water into the hydrogen underwater energy storage and power generation caisson 21. At the same time, the hydrogen in the hydrogen underwater energy storage and power generation caisson 21 is compressed. As the water level in the hydrogen underwater energy storage and power generation caisson 21 rises, the hydrogen continues to be compressed. When the pressure in the hydrogen underwater energy storage and power generation caisson 21 is greater than the pressure in the compressed hydrogen float 5, the compressed gas is compressed into the compressed hydrogen float 5 through the hydrogen inlet and outlet compressed gas pipeline 14 and the compressed hydrogen check valve 20 for storage.

[0039] When the oxygen underwater energy storage and power generation caisson 22 is storing energy, the water pump of the oxygen underwater energy storage and power generation caisson water pump / hydro turbine integrated machine 27 is started to discharge the water inside the oxygen underwater energy storage and power generation caisson 22. At the same time, the internal pressure of the oxygen underwater energy storage and power generation caisson 22 is relatively reduced. At this time, the oxygen inlet and outlet compressed gas pipeline 18 draws the gas stored in the oxygen storage float 6 into the oxygen underwater energy storage and power generation caisson 22 through the oxygen check valve 17.

[0040] When the oxygen-saturated submersible energy storage and power generation caisson 22 generates electricity, the turbine of the integrated pump / turbine unit 27 of the oxygen-saturated submersible energy storage and power generation caisson 22 is started. The turbine drives the turbine to generate electricity through the water head pressure, and discharges water into the oxygen-saturated submersible energy storage and power generation caisson 22. At the same time, the oxygen in the oxygen-saturated submersible energy storage and power generation caisson 22 is compressed. As the water level in the oxygen-saturated submersible energy storage and power generation caisson 22 rises, the oxygen continues to be compressed. When the pressure in the oxygen-saturated submersible energy storage and power generation caisson 22 is greater than the pressure in the compressed oxygen float 7, the compressed gas is compressed into the compressed oxygen float 7 through the oxygen inlet and outlet compressed gas pipeline 18 and the compressed hydrogen check valve 29 for storage.

[0041] In the hydrogen production and storage island of the floating photovoltaic, electrochemical, and hydrogen production process, the control of gas during the underwater energy storage and power generation process is similar to the principle of an air pump.

[0042] This invention also provides a control method for a hydrogen production and storage island for hydroelectric photovoltaic power generation, comprising the following steps: Step (1) To ensure optimized hydrogen production in the floating photovoltaic and electrochemical hydrogen production and storage islands, and to reduce the buoyancy balance of the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson, based on the principle of on-site consumption of photovoltaic power generation, optimized control rules are formulated according to the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson, including: 1) During the process of using a variable frequency water pump to drain water and store energy during the photovoltaic power generation hydrogen production and waste electricity production: a. When the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson are equal, the variable frequency water pump of the hydrogen underwater energy storage and power generation caisson should be prioritized for drainage and energy storage.

[0043] b. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is greater than or equal to the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the drainage flow rate of the variable frequency water pump in the underwater energy storage and power generation caisson with the higher water level is controlled according to the current photovoltaic irradiance and the photovoltaic cell IV curve, so as to realize the maximum power variable frequency water pump drainage energy storage of the photovoltaic array.

[0044] c. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is less than the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the flow rate of the variable frequency pump in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson can be controlled in a time-sharing manner based on the current photovoltaic irradiance and the photovoltaic cell IV curve to ensure the relative balance of the water levels in either the hydrogen or oxygen underwater energy storage and power generation caisson.

[0045] 2) During the process of generating hydrogen from photovoltaic power generation, when the turbine is drawing water to generate electricity, the following occurs: a. When the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson are equal, the turbine output power of the hydrogen underwater energy storage and power generation caisson should be prioritized for water inflow and power generation based on the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve.

[0046] b. When the sum of the water levels in the hydrogen-water and oxygen-water submerged energy storage and power generation caissons is less than the full water level in either the hydrogen-water or oxygen-water submerged energy storage and power generation caisson, the turbine power generation power and flow rate are controlled according to the current turbine head pressure, photovoltaic irradiance intensity, and photovoltaic cell IV curve. Under the condition of ensuring the maximum power output of the photovoltaic array, the turbine power generation in either the hydrogen-water or oxygen-water submerged energy storage and power generation caisson is controlled in a time-sharing manner to ensure the relative balance of the water levels in either the hydrogen-water or oxygen-water submerged energy storage and power generation caisson.

[0047] c. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is greater than or equal to the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the power generation power and flow rate of the underwater energy storage and power generation caisson at the low water level are controlled according to the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve.

[0048] Step (2) When the maximum output power of photovoltaic power generation meets the hydrogen production power of water electrolysis, control the photovoltaic power generation to supply hydrogen to the electrolysis equipment through power distribution and control equipment, and the generated hydrogen and oxygen enter the hydrogen storage float and oxygen storage float respectively.

[0049] Step (3) When the photovoltaic power generation exceeds the hydrogen production power of water electrolysis, the excess photovoltaic power is absorbed by the variable frequency pump of the hydrogen or oxygen underwater energy storage power generation caisson. Since the power of the water electrolysis hydrogen production equipment, the power range of the variable frequency pump of the underwater energy storage power generation caisson, the output power range of the water turbine, the irradiance, the characteristics of the photovoltaic modules, and the rated power of the photovoltaic array are known, the drainage power of the variable frequency pump of the underwater energy storage power generation caisson is determined by combining the photovoltaic cell IV curve lookup table and calculation analysis to ensure the maximum power output of the photovoltaic array and achieve the best efficiency of hydrogen production by the photovoltaic array. The generated hydrogen and oxygen enter the hydrogen storage float and the oxygen storage float, respectively. At the same time, due to the start of the variable frequency pump of the hydrogen or oxygen underwater energy storage power generation caisson for drainage energy storage, the water inside the hydrogen or oxygen underwater energy storage power generation caisson is discharged. At this moment, the pressure inside the hydrogen or oxygen underwater energy storage power generation caisson is relatively reduced, and the gas stored in the hydrogen or oxygen float is drawn into the hydrogen or oxygen underwater energy storage power generation caisson through the hydrogen or oxygen inlet / outlet pipe, hydrogen check valve, or oxygen check valve.

[0050] Step (4) When the photovoltaic power generation is less than the hydrogen production power of water electrolysis, the hydrogen production power is supplemented by the turbine power generation of the hydrogen underwater energy storage power generation tank or the oxygen underwater energy storage power generation tank. Since the power of the water electrolysis hydrogen production equipment, the power range of the variable frequency water pump and the output power range of the water turbine of the underwater energy storage power generation tank, the irradiance, the characteristics of the photovoltaic module and the rated power of the photovoltaic array are known, the output power of the water turbine power generation of the underwater energy storage power generation tank is determined by combining the IV curve of the solar cell with table lookup and calculation analysis, so as to achieve the best efficiency of hydrogen production by photovoltaic array and water turbine power generation. At this time, the water turbine of the integrated pump / water turbine is driven by the seawater head pressure to generate electricity and discharge seawater into the hydrogen or oxygen underwater energy storage power generation tank. At this time, the water turbine power generation and photovoltaic power generation are supplemented by photovoltaic power generation to supply hydrogen production to the electrolysis equipment under the control of the power distribution and control equipment. As the water level in the hydrogen or oxygen underwater energy storage power generation tank rises, the hydrogen or oxygen in the hydrogen or oxygen underwater energy storage power generation tank is compressed. When the pressure inside the hydrogen or oxygen underwater energy storage caisson is greater than the pressure of the compressed hydrogen or oxygen storage pontoon, the compressed hydrogen or oxygen gas is compressed into the compressed hydrogen or oxygen gas chamber for storage through the hydrogen or oxygen inlet and outlet pipelines and the compressed hydrogen or compressed oxygen check valve.

[0051] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A floating photovoltaic electrochemical hydrogen production and storage island, characterized in that: This includes photovoltaic arrays, gas storage pontoons, photovoltaic support pontoons, water electrolysis hydrogen production chambers, and underwater energy storage power generation caissons; The photovoltaic array consists of several photovoltaic strings, each of which is a rectangular structure. Photovoltaic support floats are installed at the four corners of the photovoltaic strings, and gas storage floats are evenly distributed on one of the photovoltaic strings at the edge of the photovoltaic array, floating on the water surface to support the photovoltaic strings. The underwater energy storage and power generation caisson is anchored to the bottom of the water body, and the water electrolysis hydrogen production chamber is fixedly installed on the top of the underwater energy storage and power generation caisson and placed in the water body; The photovoltaic array floats on the water body with the support of the gas storage float and the photovoltaic support float. It converts light energy into electrical energy, which is then used to provide power for hydrogen production by water electrolysis and the drainage energy storage of the underwater energy storage power generation caisson through power distribution and control equipment. The photovoltaic support float includes a float, a support, and a combiner box. It has a cylindrical upper section and a conical sealed lower section. The support is placed on the float, and the combiner box is installed in the support. The photovoltaic power generation is output to the power distribution and control equipment through the combiner box. The gas storage floats include hydrogen storage floats, compressed hydrogen floats, oxygen storage floats, and compressed oxygen floats; The electrolysis hydrogen production chamber includes an electrolysis hydrogen production chamber body, an electrolysis hydrogen production equipment, a reverse osmosis seawater desalination or water filtration device, power distribution and control equipment, a hydrogen delivery pipeline and an oxygen delivery pipeline. To ensure optimized hydrogen production in the floating photovoltaic and electrochemical hydrogen production and storage islands, and to reduce the buoyancy balance of the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson, the principle of on-site consumption of photovoltaic power generation is adopted, and optimized control rules are formulated based on the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson. 1) During the process of using a variable frequency water pump to drain water and store energy during the photovoltaic power generation hydrogen production and waste electricity production: a. When the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson are equal, the variable frequency water pump of the hydrogen underwater energy storage and power generation caisson should be controlled first to drain and store energy. b. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is greater than or equal to the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the drainage flow rate of the variable frequency water pump in the underwater energy storage and power generation caisson with the higher water level is controlled according to the current photovoltaic irradiance and the photovoltaic cell IV curve, so as to realize the maximum power variable frequency water pump drainage energy storage of the photovoltaic array. c. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is less than the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the flow rate of the variable frequency pump in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson can be controlled in a time-sharing manner based on the current photovoltaic irradiance and the photovoltaic cell IV curve to ensure that the water level in either the hydrogen or oxygen underwater energy storage and power generation caisson is relatively balanced. 2) During the process of generating hydrogen from photovoltaic power generation, when the turbine is drawing water to generate electricity, the following occurs: a. When the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson are equal, the turbine output power of the hydrogen underwater energy storage and power generation caisson should be prioritized for water inflow and power generation based on the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve. b. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is less than the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the power generation power and flow rate of the turbine are controlled according to the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve. Under the condition of ensuring the maximum power output of the photovoltaic array, the turbine power generation of either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson is controlled in a time-sharing manner to ensure the relative balance of the water levels in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson. c. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is greater than or equal to the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the power generation power and flow rate of the underwater energy storage and power generation caisson at the low water level are controlled according to the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve.

2. The floating photovoltaic electrochemical hydrogen production and storage island according to claim 1, characterized in that: The hydrogen storage float, compressed hydrogen float, oxygen storage float, and compressed oxygen float are all cylindrical rigid structures installed on the four sides of a photovoltaic string in the photovoltaic array. The hydrogen storage float, compressed hydrogen float, oxygen storage float, and compressed oxygen float are all connected to the photovoltaic string through the installed brackets and float on the water surface to support the photovoltaic string. The compressed hydrogen float is equipped with a compressed hydrogen outlet, and the compressed oxygen float is equipped with a compressed oxygen outlet.

3. The floating photovoltaic electrochemical hydrogen production and storage island according to claim 1, characterized in that: The bottom of the hydrogen storage float is equipped with hydrogen inlet and outlet pipes, which are connected to the inside of the hydrogen storage float. The other end of the hydrogen inlet and outlet pipes are connected to the hydrogen inlet and outlet compressed gas pipes via hydrogen check valves, and also pass through the water electrolysis hydrogen production chamber and are connected to the hydrogen outlet of the water electrolysis hydrogen production chamber, so as to store the hydrogen produced by water electrolysis in the hydrogen storage float. The bottom of the oxygen storage float is equipped with oxygen inlet and outlet pipes, which are connected to the inside of the oxygen storage float. The other end of the oxygen inlet and outlet pipes are connected to the oxygen inlet and outlet compressed gas pipes via oxygen check valves, and also pass through the water electrolysis hydrogen production chamber and are connected to the oxygen outlet of the water electrolysis hydrogen production chamber, so as to store the oxygen produced by water electrolysis in the oxygen storage float.

4. The floating photovoltaic electrochemical hydrogen production and storage island according to claim 1, characterized in that: A compressed hydrogen outlet is installed on the upper side of the compressed hydrogen float. The bottom of the compressed hydrogen float is connected to the inlet and outlet compressed hydrogen gas pipeline via a compressed hydrogen check valve, and is also connected to the interior of the compressed hydrogen float. The other end of the inlet and outlet compressed hydrogen gas pipeline is placed on top of the hydrogen underwater energy storage and power generation tank and is connected to the interior, storing the compressed hydrogen generated during the power generation process in the compressed hydrogen float. Similarly, a compressed oxygen outlet is installed on the upper side of the compressed oxygen float. The bottom of the compressed oxygen float is connected to the inlet and outlet compressed oxygen gas pipeline via a compressed oxygen check valve, and is also connected to the interior of the compressed oxygen float. The other end of the inlet and outlet compressed oxygen gas pipeline is placed on top of the oxygen underwater energy storage and power generation tank and is connected to the interior, storing the compressed oxygen generated during the power generation process in the compressed oxygen float.

5. A floating photovoltaic electrochemical hydrogen production and storage island according to claim 1, characterized in that: The water electrolysis hydrogen production equipment and power distribution and control equipment are fixedly installed at the bottom of the water electrolysis hydrogen production chamber. The hydrogen production port of the water electrolysis hydrogen production equipment is connected to the hydrogen inlet and outlet pipes, and the other end of the hydrogen inlet and outlet pipes is connected to the inside of the hydrogen storage float. The hydrogen produced by the water electrolysis hydrogen production equipment is discharged into the hydrogen storage float through the hydrogen inlet and outlet pipes. The oxygen production port of the water electrolysis hydrogen production equipment is connected to the oxygen inlet and outlet pipes, and the other end of the oxygen inlet and outlet pipes is connected to the inside of the oxygen storage float. The oxygen produced by the water electrolysis hydrogen production equipment is discharged into the oxygen storage float through the oxygen inlet and outlet pipes.

6. The floating photovoltaic electrochemical hydrogen production and storage island according to claim 1, characterized in that: The power distribution and control equipment is connected to the combiner box and the power supply systems for the hydrogen underwater energy storage power generation caisson and the oxygen underwater energy storage power generation caisson via cables. The turbine power generation of the hydrogen underwater energy storage power generation caisson water pump / turbine integrated unit, the turbine power generation of the oxygen underwater energy storage power generation caisson water pump / turbine integrated unit, and the photovoltaic array provide power to the water electrolysis hydrogen production equipment. By controlling the water pumps of the hydrogen underwater energy storage power generation caisson water pump / turbine integrated unit and the oxygen underwater energy storage power generation caisson water pump / turbine integrated unit, water is pumped into the corresponding underwater energy storage power generation caisson to store energy, ensuring the stability of the power supply for water electrolysis hydrogen production.

7. A floating photovoltaic electrochemical hydrogen production and storage island according to claim 1, characterized in that: The reverse osmosis seawater desalination or water filtration device is embedded in the water electrolysis hydrogen production chamber. One end of the reverse osmosis seawater desalination or water filtration device passes through the water electrolysis hydrogen production chamber and is connected to the fresh water input end, while the other end is connected to the water body. The reverse osmosis seawater desalination or water filtration device uses the pressure difference between the depth pressure of the water body and the pressure at the fresh water input end of the water electrolysis hydrogen production equipment to provide fresh water to the water electrolysis hydrogen production equipment.

8. A floating photovoltaic electrochemical hydrogen production and storage island according to claim 1, characterized in that: The underwater energy storage and power generation caissons include a hydrogen underwater energy storage and power generation caisson and an oxygen underwater energy storage and power generation caisson. The hydrogen underwater energy storage and power generation caissons and the oxygen underwater energy storage and power generation caissons can be cuboid or tank-shaped structures, connected to each other, and placed in the lower part of the water electrolysis hydrogen production chamber, at the bottom of the water body. The hydrogen underwater energy storage and power generation caisson is equipped with an integrated hydrogen underwater energy storage and power generation caisson water pump / turbine and hydrogen inlet and outlet compressed gas pipelines; the oxygen underwater energy storage and power generation caisson is equipped with an integrated oxygen underwater energy storage and power generation caisson water pump / turbine and oxygen inlet and outlet compressed gas pipelines; the integrated hydrogen underwater energy storage and power generation caisson water pump / turbine is embedded in the hydrogen underwater energy storage and power generation caisson near the bottom, one end of the integrated hydrogen underwater energy storage and power generation caisson water pump / turbine is connected to the inside of the hydrogen underwater energy storage and power generation caisson, and the other end of the integrated hydrogen underwater energy storage and power generation caisson water pump / turbine is placed in the water body; The integrated pump / turbine unit for underwater energy storage and power generation is embedded and installed near the bottom of the underwater energy storage and power generation caisson. One end of the integrated pump / turbine unit is connected to the inside of the underwater energy storage and power generation caisson, while the other end of the pump / turbine unit is placed in the water. The hydrogen underwater energy storage and power generation caisson water pump / turbine integrated unit and the oxygen underwater energy storage and power generation caisson water pump / turbine integrated unit are respectively an adjustable flow rate variable frequency water pump and a controllable output power water turbine; One end of the hydrogen inlet and outlet compressed gas pipeline is installed through the top of the hydrogen underwater energy storage and power generation tank and is connected to the gas inside the hydrogen underwater energy storage and power generation tank. The other end of the hydrogen inlet and outlet compressed gas pipeline is connected to the compressed hydrogen float through a compressed hydrogen check valve and to the hydrogen inlet and outlet pipeline through a hydrogen check valve. One end of the oxygen inlet and outlet compressed gas pipeline is installed through the top of the oxygen underwater energy storage and power generation caisson and is connected to the gas inside the oxygen underwater energy storage and power generation caisson. The other end of the oxygen inlet and outlet compressed gas pipeline is connected to the compressed oxygen float through a compressed oxygen check valve and to the oxygen inlet and outlet compressed gas pipeline through an oxygen check valve.

9. A control method for a hydroelectric hydrogen production and storage island based on any one of claims 1-8, characterized in that, Includes the following steps: Step (1) In order to ensure the optimization of hydrogen production in the hydrogen storage island of the floating photovoltaic and electrochemical hydrogen production, and at the same time reduce the buoyancy balance of the hydrogen underwater energy storage power generation caisson and the oxygen underwater energy storage power generation caisson, the principle of local consumption of photovoltaic power generation is adopted, and the optimization control rules are formulated based on the water level in the hydrogen underwater energy storage power generation caisson and the oxygen underwater energy storage power generation caisson. Step (2) When the maximum output power of photovoltaic power generation meets the hydrogen production power of water electrolysis, control the photovoltaic power generation to supply hydrogen to the water electrolysis hydrogen production equipment through power distribution and control equipment, and the generated hydrogen and oxygen enter the hydrogen storage float and oxygen storage float respectively. Step (3) When the photovoltaic power generation is greater than the hydrogen production power of water electrolysis, the excess power of the photovoltaic power generation is absorbed by the variable frequency water pump of the hydrogen or oxygen underwater energy storage power generation caisson; according to the power of the water electrolysis hydrogen production equipment, the power range of the variable frequency water pump of the underwater energy storage power generation caisson and the output power range of the water turbine, the photovoltaic irradiance, the characteristics of the photovoltaic module and the rated power of the photovoltaic array, combined with the photovoltaic cell IV curve lookup table and calculation analysis, the drainage power of the variable frequency water pump of the hydrogen or oxygen underwater energy storage power generation caisson is determined to ensure the maximum power output of the photovoltaic and achieve the best efficiency of the photovoltaic array to produce hydrogen; the generated hydrogen and oxygen enter the hydrogen storage gas float and the oxygen storage gas float respectively; at the same time, the variable frequency water pump of the hydrogen or oxygen underwater energy storage power generation caisson is started to drain the energy storage, and the water inside the hydrogen or oxygen underwater energy storage power generation caisson is discharged. The gas stored in the hydrogen storage gas float or the oxygen storage gas float is sucked into the hydrogen or oxygen underwater energy storage power generation caisson through the hydrogen inlet and outlet pipeline or the oxygen inlet and outlet pipeline, the hydrogen check valve or the oxygen check valve. Step (4) When the photovoltaic power generation is less than the hydrogen production power of water electrolysis, the water turbine of the hydrogen underwater energy storage power generation tank or the oxygen underwater energy storage power generation tank is used to supplement the hydrogen production power of water electrolysis; the water turbine of the integrated hydrogen or oxygen water pump / water turbine is controlled to drive the power generation using the seawater head pressure, and the seawater is discharged into the hydrogen or oxygen underwater energy storage power generation tank. At this time, the water turbine power generation and photovoltaic power generation are under the control of the power distribution and control equipment to supplement the photovoltaic power generation to supply hydrogen to the water electrolysis hydrogen production equipment; when the pressure in the hydrogen or oxygen underwater energy storage power generation tank is greater than the pressure of the compressed hydrogen float or compressed oxygen float, the hydrogen or oxygen compressed gas is compressed into the compressed hydrogen float or compressed oxygen float for storage through the hydrogen inlet and outlet pipeline or the oxygen inlet and outlet pipeline, and through the compressed hydrogen check valve or the compressed oxygen check valve.

10. The control method according to claim 9, characterized in that, Step (1) includes: 1) During the process of using a variable frequency water pump to drain water and store energy during the photovoltaic power generation hydrogen production and waste electricity production: a. When the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson are equal, the variable frequency water pump of the hydrogen underwater energy storage and power generation caisson should be controlled first to drain and store energy. b. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is greater than or equal to the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the drainage flow rate of the variable frequency water pump in the underwater energy storage and power generation caisson with the higher water level is controlled according to the current photovoltaic irradiance and the photovoltaic cell IV curve, so as to realize the maximum power variable frequency water pump drainage energy storage of the photovoltaic array. c. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is less than the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the flow rate of the variable frequency pump in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson can be controlled in a time-sharing manner based on the current photovoltaic irradiance and the photovoltaic cell IV curve to ensure that the water level in either the hydrogen or oxygen underwater energy storage and power generation caisson is relatively balanced. 2) During the process of generating hydrogen from photovoltaic power generation, when the turbine is drawing water to generate electricity, the following occurs: a. When the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson are equal, the turbine output power of the hydrogen underwater energy storage and power generation caisson should be prioritized for water inflow and power generation based on the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve. b. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is less than the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the power generation power and flow rate of the turbine are controlled according to the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve. Under the condition of ensuring the maximum power output of the photovoltaic array, the turbine power generation of either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson is controlled in a time-sharing manner to ensure the relative balance of the water levels in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson. c. When the sum of the water levels in the hydrogen underwater energy storage and power generation caisson and the oxygen underwater energy storage and power generation caisson is greater than or equal to the full water level in either the hydrogen underwater energy storage and power generation caisson or the oxygen underwater energy storage and power generation caisson, the power generation power and flow rate of the underwater energy storage and power generation caisson at the low water level are controlled according to the current turbine head pressure, photovoltaic irradiance intensity and photovoltaic cell IV curve.

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