Offshore photovoltaic power generation device integrating pumped storage function

Abstract

The invention relates to the technical field of installation of photoelectric combination cables or electric wires, and provides an offshore photovoltaic power generation device with a pumped storage function, which comprises a photovoltaic power generation assembly, the photovoltaic power generation assembly is installed on the top plane of a water storage cavity, and a plurality of PHC precast piles are installed at the bottom of the water storage cavity and are used for supporting and inserting into a seabed. The bottom of the water storage cavity is connected with a water inlet pipe and a submarine cable, the submarine cable is tightly attached to the PHC precast pile and the seabed surface, the opening end of the water inlet pipe is higher than the seabed surface, the submarine cable is communicated to an inner cavity of the water storage cavity through a water outlet valve, the water inlet pipe is communicated to the inner cavity of the water storage cavity through a water pump, and a water wheel is installed in the water storage cavity at the position where the submarine cable is connected to the water storage cavity. The invention further provides an offshore photovoltaic power generation device control system integrating the pumped storage function. Through the reasonable combination structure, the stability of offshore photovoltaic power generation can be greatly improved, the energy storage capacity is large, expansion or reduction is easy, energy storage and energy release are easy to control, the advantages of the sea surface are fully utilized, and the good market prospect is achieved.

Description

Technical Field

[0001] The invention relates to an offshore photovoltaic power generation device with pumped storage function, belonging to the technical field of installation of photovoltaic combined cables or wires. Background Art

[0002] The development and utilization of new energy fields such as photovoltaics and wind power have ushered in a new situation of development under the background of dual carbon goals. However, in recent years, with the large-scale installation and commissioning of new energy such as photovoltaics and wind power, the randomness and volatility of new energy have caused the problem of renewable energy abandonment in the energy system to become increasingly serious. The large-scale consumption of large-scale renewable surplus electricity is a new problem for my country's energy system. The improvement of energy storage systems is an effective technical means to alleviate the problem of abandoned electricity.

[0003] At present, energy storage can be divided into three categories: mechanical energy storage, electrochemical energy storage and electromagnetic energy storage. Among them, the most commonly used mechanical energy storage is pumped storage and compressed air energy storage. At present, in the field of offshore photovoltaic energy storage, there are many public inventions that use electrochemical energy storage to electrolyze seawater for hydrogen production (such as CN117902007A, CN115940751A) and compressed air energy storage (such as CN117811465A). Compared with electrochemical and compressed air energy storage, pumped storage has the advantages of mature technology, fast load response speed, good regulation ability, low cost, long life, etc. Its efficiency can generally reach 65% to 75%, and up to 80% to 85%. At the same time, abundant seawater resources can be utilized. An invention has disclosed its application in offshore wind power energy storage (such as CN117090736A). However, the pumped storage solutions in the prior art still have problems such as unreasonable structure and low energy storage capacity. They either fail to fully utilize the advantages of the sea surface or cannot effectively expand the energy storage capacity. In addition, the energy storage and release process is difficult to control, which leads to insufficient stability of offshore photovoltaic power generation. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an offshore photovoltaic power generation device with integrated pumped storage function. The offshore photovoltaic power generation device with integrated pumped storage function can greatly improve the stability of offshore photovoltaic power generation through a reasonable combination structure. The energy storage capacity is large and easy to expand or reduce. The energy storage and release are easy to control, and the advantages of the sea surface are fully utilized. It has excellent market prospects.

[0005] The present invention is achieved through the following technical solutions.

[0006] The present invention provides an offshore photovoltaic power generation device with pumped storage function, comprising a photovoltaic power generation component, which is installed on the top plane of a water storage cavity, a plurality of PHC prefabricated piles are installed at the bottom of the water storage cavity for supporting and inserting into the seabed, a water inlet pipe and a submarine cable are respectively connected to the bottom of the water storage cavity, the submarine cable is installed close to the PHC prefabricated piles and the seabed surface, the opening end of the water inlet pipe is higher than the seabed surface, the submarine cable is connected to the inner cavity of the water storage cavity through a water outlet valve, the water inlet pipe is connected to the inner cavity of the water storage cavity through a water pump, a water wheel is installed in the water storage cavity at the position where the submarine cable is connected to the water storage cavity, and the water wheel is connected to a hydro-turbine generator; the photovoltaic power generation component and the hydro-turbine generator are both electrically connected to a power output line.

[0007] The water turbine generator is embedded in the bottom wall of the water storage cavity.

[0008] The photovoltaic power generation components are distributed in a ring array on the top plane of the water storage cavity, and the photovoltaic power generation components on the inner layer are higher than the photovoltaic power generation components on the outer layer.

[0009] A boat landing structure is provided at the center of the top of the water storage cavity, and an inspection well is installed on the side wall of the water storage cavity.

[0010] The water wheel is an impeller structure.

[0011] The position where the water inlet pipe is connected to the water storage cavity has a water inlet valve installed in the water storage cavity.

[0012] The present invention also provides a control system for an offshore photovoltaic power generation device with a pumped storage function; the control system is used to control the offshore photovoltaic power generation device with a pumped storage function as described above, comprising: The acquisition module is connected to the photovoltaic power generation system communication bus and is connected to control the water level sensor, which is installed in the inner cavity of the water storage chamber; The judgment module is connected to the acquisition module and obtains the acquisition data output by the acquisition module; The execution module is connected to the judgment module for communication and obtains the judgment data output by the judgment module, and is connected to control the water pump, the water outlet valve and the water inlet valve installed in the water storage cavity to control the flow rate of the water inlet pipe.

[0013] The acquisition module obtains the power grid demand and the power output of the photovoltaic power generation assembly from the photovoltaic power generation system communication bus, and obtains the water level data in the water storage cavity from the water level sensor.

[0014] The judgment module judges the operation status according to the grid demand, the power output of the photovoltaic power generation component and the water level data in the water storage chamber. The operation status includes normal, overpower supply and energy storage, overpower supply and insufficient power supply.

[0015] The execution module controls the water pump, the water outlet valve and the water inlet valve according to the operating status: If the operating status is normal or there is excess power supply, close the water pump, water outlet valve, and water inlet valve; If the operating status is insufficient power supply, open the water outlet valve and close the water pump and water inlet valve; If the operating state is excess power supply and energy storage, open the water pump and water inlet valve, and close the water outlet valve.

[0016] The beneficial effects of the present invention are: through a reasonable combination structure, the stability of offshore photovoltaic power generation can be greatly improved, the energy storage capacity is large and easy to expand or reduce, the energy storage and release are easy to control, and the advantages of the sea surface are fully utilized, so there is an excellent market prospect; it is convenient to carry out operation and maintenance operations; the construction and installation difficulty is low, and the risk and economic cost are low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the structure of at least one embodiment of the present invention; Figure 2 yes Figure 1 Side view of Figure 3 yes Figure 1 Bottom view of Figure 4 yes Figure 1 A top view of Figure 5 yes Figure 4 Sectional view of the middle AA plane; Figure 6 yes Figure 5 Middle BB view; Figure 7 is a connection diagram of at least one embodiment of the present invention; Figure 8 yes Figure 7 Schematic diagram of the workflow of the judgment module; Fig. 9 yes Figure 7 Schematic diagram of the workflow of the execution module.

[0018] In the figure: 1-photovoltaic power generation component, 2-water storage cavity, 3-PHC prefabricated pile, 4-ship landing structure, 5-inspection well, 6-water inlet pipe, 7-water pump, 8-water outlet, 9-water outlet valve, 10-water wheel, 11-hydraulic generator, 12-submarine cable, 13-water inlet valve. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0020] A first embodiment of the present invention relates to Figures 1 to 6An offshore photovoltaic power generation device with pumped storage function shown in the figure comprises a photovoltaic power generation component 1, which is installed on the top plane of a water storage cavity 2. A plurality of PHC prefabricated piles 3 are installed at the bottom of the water storage cavity 2 for supporting and inserting into the seabed. A water inlet pipe 6 and a submarine cable 12 are respectively connected to the bottom of the water storage cavity 2. The submarine cable 12 is installed close to the PHC prefabricated piles 3 and the seabed surface. The opening end of the water inlet pipe 6 is higher than the seabed surface. The submarine cable 12 is connected to the inner cavity of the water storage cavity 2 through a water outlet valve 9. The water inlet pipe 6 is connected to the inner cavity of the water storage cavity 2 through a water pump 7. A water wheel 10 is installed in the water storage cavity 2 at the position where the submarine cable 12 is connected to the water storage cavity 2, and the water wheel 10 is connected to a hydro-generator 11; the photovoltaic power generation component 1 and the hydro-generator 11 are both electrically connected to the power output line.

[0021] The second embodiment of the present invention is substantially the same as the first embodiment, mainly in that the hydro-generator 11 is embedded in the bottom wall of the water storage cavity 2 .

[0022] Furthermore, the photovoltaic power generation components 1 are distributed in a ring array on the top plane of the water storage cavity 2, and the photovoltaic power generation components 1 on the inner layer are higher than the photovoltaic power generation components 1 on the outer layer.

[0023] Furthermore, a boat landing structure 4 is provided at the center of the top of the water storage cavity 2 , and an inspection well 5 is installed on the side wall of the water storage cavity 2 .

[0024] Furthermore, the water wheel 10 is an impeller structure.

[0025] Furthermore, a water inlet valve 13 is installed in the water storage chamber 2 at the position where the water inlet pipe 6 is connected to the water storage chamber 2 .

[0026] The maximum energy storage capacity of the present invention can be estimated as follows: , in, E max is the total maximum energy storage capacity, kW·h; E i For the i The energy storage capacity of the water body, kW·h, can be calculated as follows: , In the formula, ξ 水泵 is the pump motor efficiency; 发电机 is the generator conversion efficiency; 传动 is the mechanical transmission efficiency between components; Δ V i The first i Volume of the water layer, m 3 ; H i The first iThe average hydraulic head of the water layer, m.

[0027] Typically, Can be used VH m Simplify the calculation. Among them, V is the maximum water storage capacity of the water storage cavity, which can be calculated as follows: , In the formula, r is the inner diameter of the water storage cavity, m; h 1 , h 2 are the maximum and minimum elevations inside the water storage cavity, m; V 泵 is the external structure volume of the pump, m 3 , V 水泵 = oeLh . l is the outer length of the pump, m, w is the outer width of the pump, m; h is the outer height of the pump, m.

[0028] H m is the maximum average water head of the water storage cavity, which can be calculated as follows: , In the formula, h 1 , h 2 Same as above; h L Design minimum water level for the sea area where the water is located, m.

[0029] A third embodiment of the present invention relates to Figure 7 The control system of an offshore photovoltaic power generation device with pumped storage function shown is used to control the first or second embodiment described above, comprising: The acquisition module is connected to the photovoltaic power generation system communication bus and connected to the control water level sensor, which is installed in the inner cavity of the water storage cavity 2; The judgment module is connected to the acquisition module and obtains the acquisition data output by the acquisition module; The execution module is connected to the judgment module for communication and obtains the judgment data output by the judgment module, and is connected to control the water pump 7, the water outlet valve 9 and the water inlet valve 13 installed in the water storage cavity 2 to control the flow rate of the water inlet pipe 6.

[0030] Furthermore, the acquisition module obtains the grid demand and the power output of the photovoltaic power generation assembly 1 from the photovoltaic power generation system communication bus, and obtains the water level data in the water storage cavity 2 from the water level sensor.

[0031] Furthermore, the judgment module judges the operating status according to the grid demand, the power output of the photovoltaic power generation component 1 and the water level data in the water storage chamber 2. The operating status includes normal, excess power supply and energy storage, excess power supply and insufficient power supply.

[0032] Furthermore, the execution module controls the water pump 7, the water outlet valve 9, and the water inlet valve 13 according to the operating status, such as Figure 8 As shown: If the operating status is normal or the power supply is excessive, the water pump 7, the water outlet valve 9, and the water inlet valve 13 are closed; If the operating state is insufficient power supply, the water outlet valve 9 is opened, and the water pump 7 and the water inlet valve 13 are closed; If the operating state is excess power supply and energy storage, the water pump 7 and the water inlet valve 13 are opened, and the water outlet valve 9 is closed.

[0033] The fourth embodiment of the present invention is combined with the above embodiments, and is connected to the power grid via a submarine cable to achieve power transmission.

[0034] The supporting structure system includes a water storage cavity, multiple PHC prefabricated piles, a docking landing structure, and a maintenance well. The water storage cavity is a cylindrical cavity that can store water inside, and a number of photovoltaic power generation components are installed on the top. The top of the PHC prefabricated pile is connected to the water storage cavity, and the lower part is inserted into the seabed to a certain depth, which can keep the device stable under the self-weight load and wave and current load of the upper photovoltaic power generation components, water storage cavity and water body. The docking landing structure is set at an appropriate position outside the water storage cavity to facilitate the operation and maintenance of ships and personnel to log in. The maintenance well is located at the center of the top of the water storage cavity, which can facilitate the operation and maintenance personnel and equipment to enter the water storage cavity.

[0035] The pumped storage system includes an inlet pipe, a water pump, an inlet valve, an outlet hole, an outlet valve and a turbine generator. One end of the inlet pipe is connected to the water pump, and the other end passes through the bottom of the water storage cavity, and the lower part enters below the sea surface (below the designed low water level). The water pump is arranged at the bottom of the water storage cavity, and can pump seawater into the water storage cavity through the inlet pipe. The outlet hole is located at the bottom of the water storage cavity, and a turbine generator and an outlet valve are arranged in the hole. The power generated by the generator is connected to the power grid through a submarine cable to realize power transmission.

[0036] The intelligent control system is located in the shore-side centralized control center and is used for intelligent automatic control of various systems of the power generation device. It is electrically connected to the photovoltaic power generation system, power grid, water pump, water inlet valve, and water outlet valve. The intelligent control system includes a collection module, a judgment module, and an execution module. The modules are electrically connected to each other to express electrical signals. The collection module collects information data such as the output of the photovoltaic power generation system, the demand of the power grid, and the water level inside the water storage cavity in real time.

[0037] The judgment module judges the relationship between the output of the photovoltaic power generation system and the grid demand and the status of the pumped storage system, and transmits the corresponding signal to the execution module.

[0038] The judgment logic of the judgment module is: (1) When the output of the photovoltaic power generation system can meet the needs of the power grid, it is judged to be in normal state.

[0039] (2) When the output of the photovoltaic power generation system exceeds the demand of the power grid, and the water storage inside the water storage cavity has not reached the maximum elevation, it is judged to be in a state of excess power storage; when the output of the photovoltaic power generation system exceeds the demand of the power grid, but the water storage inside the water storage cavity has reached the maximum elevation, it is judged to be in a state of excess power storage.

[0040] (3) When the output of the photovoltaic power generation system is lower than the grid demand, it is judged as insufficient power supply.

[0041] The execution module controls the opening and closing of the water inlet valve and the water outlet valve and the start and stop of the water pump according to the judgment signal transmitted by the judgment module, so as to achieve the output adjustment of the photovoltaic power generation system and the pumped storage system.

[0042] The control logic is: (1) When the judgment module transmits a normal state or overpower signal, the water inlet valve, water outlet valve, and water pump are all controlled to be closed.

[0043] (2) When the judgment module transmits a signal indicating an excess power supply and energy storage state, the water inlet valve and water pump are controlled to open to extract seawater, and the seawater is sucked into the water storage chamber for energy storage.

[0044] (3) When the judgment module transmits a power shortage status signal, the water inlet valve and water pump are controlled to close, and the water outlet valve is opened. Water flows down through the outlet hole to impact the turbine generator inside to generate electricity, and the power generated by the turbine generator and the photovoltaic power generation system are combined and sent to the power grid via the submarine cable.

[0045] Thus, the present invention: (1) The effective combination of offshore photovoltaic power generation and seawater pumped storage has greatly improved the stability of offshore photovoltaic power generation. When the supply of offshore photovoltaic power generation exceeds the demand, that is, when the power supply is in excess, part of the generated electricity is converted into seawater potential energy and stored in the water storage cavity; when the supply of offshore photovoltaic power generation is less than the demand, that is, when the power supply is insufficient, the seawater potential energy is converted into electricity, and the turbine generator and photovoltaic power generation system work synchronously. This method can effectively reduce the impact of unstable offshore photovoltaic power generation on the power grid.

[0046] (2) The establishment of docking structures and inspection holes can facilitate the operation, maintenance and inspection of offshore photovoltaic power generation systems and pumped storage systems.

[0047] (3) Water storage chambers, PHC prefabricated piles, photovoltaic power generation components and other structures can be prefabricated in batches and modularly onshore, and then transported to the designated sea area for construction and installation. There is no need for large-scale offshore operations, which reduces the difficulty, risk and economic cost of construction and installation.

[0048] (4) An intelligent control system is used to monitor the relationship between offshore photovoltaic power generation output, pumped storage system status and grid load in real time, and automatically control the opening and closing of water inlet and outlet valves and water pumps based on the monitoring status, so as to achieve automatic complementarity between the photovoltaic power generation system and the pumped storage system.

Claims

1. An offshore photovoltaic power generation device with pumped storage function, comprising a photovoltaic power generation component (1), characterized in that: The photovoltaic power generation assembly (1) is installed on the top plane of the water storage cavity (2); a plurality of PHC prefabricated piles (3) are installed at the bottom of the water storage cavity (2) for supporting and inserting into the seabed; a water inlet pipe (6) and a submarine cable (12) are respectively connected to the bottom of the water storage cavity (2); the submarine cable (12) is installed close to the PHC prefabricated piles (3) and the seabed surface; the opening end of the water inlet pipe (6) is higher than the seabed surface; the submarine cable (12) is connected to the inner cavity of the water storage cavity (2) through a water outlet valve (9); the water inlet pipe (6) is connected to the inner cavity of the water storage cavity (2) through a water pump (7); a water wheel (10) is installed in the water storage cavity (2) at the position where the submarine cable (12) is connected to the water storage cavity (2); the water wheel (10) is connected to a water turbine generator (11); the photovoltaic power generation assembly (1) and the water turbine generator (11) are both electrically connected to a power output line.

2. The offshore photovoltaic power generation device with pumped storage function as claimed in claim 1, characterized in that: The hydro-generator (11) is embedded in the bottom wall of the water storage cavity (2).

3. The offshore photovoltaic power generation device with pumped storage function as claimed in claim 1, characterized in that: The photovoltaic power generation components (1) are distributed in a ring array on the top plane of the water storage cavity (2), and the photovoltaic power generation components (1) on the inner layer are higher than the photovoltaic power generation components (1) on the outer layer.

4. The offshore photovoltaic power generation device with pumped storage function as claimed in claim 1 or 3, characterized in that: A boat landing structure (4) is provided at the center of the top of the water storage cavity (2), and an inspection well (5) is installed on the side wall of the water storage cavity (2).

5. The offshore photovoltaic power generation device with pumped storage function as claimed in claim 1, characterized in that: The water wheel (10) is an impeller structure.

6. The offshore photovoltaic power generation device with pumped storage function as claimed in claim 1, characterized in that: A water inlet valve (13) is installed in the water storage chamber (2) at the position where the water inlet pipe (6) is connected to the water storage chamber (2).

7. A control system for an offshore photovoltaic power generation device with pumped storage function, characterized in that: An offshore photovoltaic power generation device with pumped storage function for controlling any one of claims 1 to 6, comprising: A collection module, connected to the photovoltaic power generation system communication bus, and connected to a control water level sensor, the water level sensor being installed in the inner cavity of the water storage cavity (2); The judgment module is connected to the acquisition module and obtains the acquisition data output by the acquisition module; The execution module is connected to the judgment module for communication and obtains judgment data output by the judgment module, and is connected to control the water pump (7), the water outlet valve (9) and the water inlet valve (13) installed in the water storage cavity (2) for controlling the flow rate of the water inlet pipe (6).

8. The offshore photovoltaic power generation device with pumped storage function as claimed in claim 1, characterized in that: The acquisition module obtains the power grid demand and the power output of the photovoltaic power generation assembly (1) from the photovoltaic power generation system communication bus, and obtains the water level data in the water storage cavity (2) from the water level sensor.

9. The offshore photovoltaic power generation device with pumped storage function as claimed in claim 2, characterized in that: The judgment module judges the operating state according to the power grid demand, the power output of the photovoltaic power generation assembly (1) and the water level data in the water storage cavity (2), and the operating state includes normal, overpower supply and energy storage, overpower supply and insufficient power supply.

10. The offshore photovoltaic power generation device with pumped storage function as claimed in claim 1, characterized in that: The execution module controls the water pump (7), the water outlet valve (9), and the water inlet valve (13) according to the operating state: If the operating status is normal or the power supply is excessive, the water pump (7), the water outlet valve (9), and the water inlet valve (13) are closed; If the operating state is insufficient power supply, the water outlet valve (9) is opened, and the water pump (7) and the water inlet valve (13) are closed; If the operating state is that the power supply is excessive and energy is stored, the water pump (7) and the water inlet valve (13) are opened, and the water outlet valve (9) is closed.

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