Pumped storage power generation system based on desalinated seawater

Abstract

The invention relates to the technical field of seawater desalination and fresh water pumped storage power generation, in particular to a pumped storage power generation system based on seawater desalination. Comprising a coast, a lower reservoir, an upper reservoir, a photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, a flow adjusting system, an energy conversion system, a seawater desalination system, an oil supply system and a protection system. According to the system, fresh water recycling is achieved, offshore wind and light energy storage, a seawater desalination system, fresh water pumped storage and fresh water storage are integrated, zero carbon emission is achieved in the electric power production link, and the problems of unbalance and instability of a photovoltaic power source are solved through pumped storage.

Description

Technical Field

[0001] The present invention relates to the technical field of seawater desalination and pumped storage power generation, and in particular to a pumped storage power generation system based on desalinated seawater. Background Art

[0002] The current pumped storage power generation system mainly focuses on seawater storage power generation. The development of reservoirs as freshwater supply and storage functions, including water supply functions during daily operation and water supply in emergency situations, is also an urgent problem to be solved. Build an upper reservoir or lower reservoir of appropriate size to replace the sea (which can be shared with seawater desalination freshwater reservoirs), and use fresh water (which can come from seawater desalination) as the energy storage medium. Compared with seawater storage power stations, the use of fresh water (which can come from seawater desalination) for energy storage reduces equipment corrosion, reduces the attachment of marine organisms, reduces related maintenance, and extends the service life, and the system takes into account the functions of freshwater supply and storage. There are many technical problems that need to be solved in developing freshwater reservoirs for pumped storage power generation, such as improving the working condition of equipment, reducing the attachment of marine organisms to the inner wall of the pipeline and equipment, ensuring work efficiency, and reducing maintenance. Reduce the corrosion of seawater to major equipment, extend the service life, and reduce the maintenance of key equipment. Pumped storage is the green, low-carbon, clean and flexible power source for the power system with the most mature technology, the best economy and the best conditions for large-scale development. It works well with wind power, solar power generation, nuclear power and thermal power.

[0003] At the same time, desalination of seawater or brackish water is an effective strategic approach to solve the problem of freshwater shortage. Vigorously developing cheap renewable energy and using it for seawater desalination will be an important way to solve the high cost of seawater desalination. Wind energy resources are very abundant at sea and on islands, with the characteristics of high wind speed and relative stability. Therefore, wind energy is an important energy option for seawater desalination. At present, there are two main ways of wind power seawater desalination: (1) wind power seawater desalination (separate type); (2) wind power directly driven seawater desalination (coupled type). Due to the advancement of wind power generation technology, wind power seawater desalination (separate type) has been widely used, but it still needs to effectively solve the link of power storage and frequency conversion. Wind power directly driven seawater desalination (coupled type) omits the "mechanical energy → electrical energy → mechanical energy" conversion process, so the energy utilization efficiency is higher and the system structure is also simplified.

[0004] In the existing technology, large-scale seawater desalination projects still need to solve the problems of integration and optimization of energy systems and their control links, so that the entire system can have a simple structure, simple operation, good stability, and low desalination cost, and can be truly suitable for the construction of large-scale, low-cost seawater desalination plants.

[0005] And through new searches, it is found that there is currently no real combination of freshwater pumped storage power generation system and seawater desalination system, as well as a system that combines upper and lower reservoirs and seawater desalination system water storage to achieve a mode of freshwater recycling. For example, the pumped storage wind energy directly driven seawater desalination integrated system disclosed in the announcement number CN104495983B has high energy conversion efficiency. The seawater desalination unit of the present invention uses a wind turbine to directly drive a reverse osmosis pump for seawater desalination. The energy conversion process is simple. Compared with the wind power seawater desalination technology, the intermediate link of converting mechanical energy into electrical energy is omitted, the energy conversion efficiency is improved, and the stability is good. The pumped storage unit of the present invention converts part of the mechanical energy provided by the wind turbine into the potential energy of seawater and stores it in a reservoir, and then uses the hydraulic turbine of the energy conversion device to convert part of the potential energy of seawater back into mechanical energy and transmit it to the seawater desalination unit. When the wind speed is low, the desalination unit is driven by the mechanical energy provided by the wind turbine and the mechanical energy provided by the hydraulic turbine, which successfully solves the problem of unstable energy supply of the reverse osmosis device caused by the randomness and volatility of wind energy, and ensures that the desalination unit can operate normally under the basic load in most cases, so that the whole system maintains a high efficiency and obtains a stable fresh water output. However, in the wind and photovoltaic power generation systems, the generator of the device needs to be lubricated. The existing one usually uses an electric motor to drive the oil pump to start and inject the lubricating oil into the generator. However, when the motor suddenly loses power, due to the lack of protective devices, the generator will burn out, affecting the normal operation of seawater desalination.

[0006] Therefore, we urgently need to provide a pumped storage power generation system based on desalinated seawater to realize the recycling of fresh water and integrate power generation, water storage and desalination of seawater. The offshore wind and solar energy storage and seawater desalination system form an integrated combination of freshwater pumped storage, which not only achieves zero carbon emissions in the power production link, but also solves the imbalance and instability of photovoltaic power sources through pumped storage. Summary of the invention

[0007] The object of the present invention is to provide a pumped storage power generation system based on desalinated seawater to solve the problems raised in the above background technology.

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a pumped storage power generation system based on desalinated seawater, comprising a coast, a lower reservoir, an upper reservoir, a photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, a flow regulation system, an energy conversion system, a seawater desalination system, an oil supply system and a protection system, wherein the lower reservoir is installed on the seabed and is a submerged pipe or caisson or other water storage structure; the upper reservoir is installed around the coast and higher than the seawater desalination system, the photovoltaic power generation system is arranged around the coast, the wind power generation system is arranged around the coast, the power system is electrically connected to the photovoltaic power generation system and the wind power generation system, the pumped storage system is arranged between the lower reservoir and the upper reservoir, the flow regulation system is installed around the coast, the input end of the energy conversion system is electrically connected to the output end of the flow regulation system, the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system, a protection system is arranged between the lower reservoir and the upper reservoir, and the output end of the protection system is connected to the input end of the oil supply system.

[0009] Furthermore, the pumped storage system includes a reversible turbine generator set, a flow pump, a pressure regulating device, and a water pipeline connecting the upper reservoir and the lower reservoir; when storing energy, offshore wind power or photovoltaic power or excess electricity on shore is used to drive the power system to drive the reversible turbine generator set of the pumped storage system to discharge water from the lower reservoir and transport it to the upper reservoir water tank at a high place, convert the electrical energy into potential energy of water and store it, so that the air pressure in the lower reservoir is 0.05-0.10 times the atmospheric pressure; when releasing energy, due to the internal and external pressure difference, the fresh water in the upper reservoir enters the lower reservoir from the high-level water tank, and drives the reversible pump turbine to generate electricity on the way, converting the potential energy of water into electrical energy. This part of the electrical energy, as well as offshore wind power and photovoltaic power, are used for the external power supply system, or for supplementing the power of the seawater desalination system.

[0010] Furthermore, when the water level of the upper reservoir is too high, due to the height difference between the upper reservoir and the seawater desalination system, the flow regulation system can be used to convert the potential energy of the water in the upper reservoir into the rotational mechanical energy of the hydraulic turbine, and then the energy is transferred to the seawater desalination system through the energy conversion system, thereby driving the operation of the seawater desalination system, that is, the input end of the energy conversion system is electrically connected to the output end of the flow regulation system, the energy conversion system includes a hydraulic turbine, a transmission and a water tank; the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system; the output ends of the photovoltaic power generation system and the wind power generation system are electrically connected to the input end of the seawater desalination system, and the electric energy generated by a part of the photovoltaic power generation system and the wind power generation system is used to power the seawater desalination system, so that the seawater desalination system desalinates seawater.

[0011] Furthermore, the protection system includes a hydro-turbine generator, a gearbox, and a gear pump; the oil supply system includes an oil tank, the generator is installed between the lower reservoir and the upper reservoir, the gearbox is connected to the output end of the generator, the gear pump is connected to the output end of the gearbox, and the oil tank is connected to the gear pump; in the process of the wind power generation system and the photovoltaic power generation system driving the power system to pump water from the lower reservoir into the upper reservoir, the water flow impacts the hydro-turbine generator of the protection system, causing the hydro-turbine generator to rotate, converting the kinetic energy of the water flow into electrical energy, providing electrical energy for the gear pump, and causing the gear pump to deliver the lubricating oil in the oil tank into each system.

[0012] Furthermore, the wind power generation system includes: a variable pitch system, a converter system, an on-site touch screen station, an Ethernet switch, a field bus communication network, a UPS power supply and an emergency shutdown backup system; the photovoltaic power generation system includes a solar cell array, a battery pack, a charge and discharge controller, an inverter and an AC distribution cabinet; the output ends of the photovoltaic power generation system and the wind power generation system are electrically connected to the input end of the seawater desalination system.

[0013] Furthermore, a pumped storage system is provided between the desalination system and the lower reservoir, through which the fresh water from the upper reservoir that flows through the desalination system and is used for power generation in the desalination system is discharged back into the lower reservoir, thereby realizing the fresh water storage function of the lower reservoir and the recycling of fresh water, protecting the interior of the power generation system from being corroded by seawater, and can also be used for water replenishment when the water level in the upper reservoir is too low and there is a water shortage.

[0014] Furthermore, a pumped storage system is provided between the desalination system and the lower reservoir, which can be connected to the upper reservoir and the lower reservoir through branch pipelines and share a pumped storage system to complete the power generation function from water supply to water discharge, thereby improving power generation efficiency and saving costs.

[0015] Furthermore, the underwater depth of the lower reservoir is 400-800m, and the ratio of the horizontal distance to the height of the upper and lower reservoirs, that is, the distance-to-height ratio is between 3.0-4.5. The lower reservoir is a plurality of energy storage pipelines with a specification of a pipeline diameter of 3m. Multiple longitudinally extending pipelines are parallel to each other and connected to the reversible turbine generator through a common pipeline. The multiple longitudinally extending parallel pipelines are made of seawater corrosion-resistant material pipes, which are covered with marine concrete and fixed to the seabed.

[0016] Furthermore, each energy storage pipeline has a short distribution pipe at the end, through which all energy storage pipelines are in communication contact, that is, the various energy storage pipelines form a large common lower reservoir, and each distribution pipe is connected to a reversible pump turbine, which has an input or output signal. At the beginning of the energy storage process, the reversible pump turbine acts as a pump turbine, and the pumped water is discharged into the upper reservoir water tank. In the case of energy demand, the whole process is reversed and the reversible pump turbine is operated as a generator. Due to the pressure difference, the water in the upper reservoir flows into the various energy storage pipelines through the distribution pipes and pipelines. Because the underwater energy storage is located at a greater depth on the seabed, the water pressure is large enough to also efficiently drive larger generators.

[0017] Each energy storage pipeline has a valve in its distribution pipe, and each of these valves can be controlled individually, that is, the energy storage pipeline that is opened or closed individually can limit the operation of the energy storage pipeline in the lower reservoir to the individual energy storage pipeline through the valve, which is particularly meaningful in the case of low energy generation or low energy demand. At the same time, this measure can optimize the working mode and efficiency of the underwater energy storage pipeline and improve the redundancy of the entire energy storage system. In addition, another advantage of setting up separate pipelines and valves is that if a certain energy storage pipeline fails, the energy storage pipeline can be closed individually, and each energy storage pipeline can be isolated from other energy storage pipelines in the system, which can avoid damage to the entire underwater energy storage pipeline.

[0018] The present invention also provides a method for laying out the above-mentioned pumped storage power generation system based on desalinated seawater, comprising the following steps:

[0019] (1) Site selection: Conduct surveys in coastal areas or islands and select a location with a lower reservoir depth of 400-800 m for construction. The ratio of the horizontal distance between the upper and lower reservoirs to their height, i.e., the distance-to-height ratio, should be between 3.0 and 4.5;

[0020] (2) A photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, a flow regulation system, an energy conversion system, a seawater desalination system, an oil supply system and a protection system are provided, wherein the lower reservoir is installed on the seabed, the flow regulation system, the photovoltaic power generation system and the wind power generation system are all provided around the coast, the power system is electrically connected to the photovoltaic power generation system and the wind power generation system, the pumped storage system is provided between the lower reservoir and the upper reservoir, the input end of the energy conversion system is electrically connected to the output end of the flow regulation system, the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system, a protection system is provided between the lower reservoir and the upper reservoir, and the output end of the protection system is connected to the input end of the oil supply system;

[0021] (3) Both the lower reservoir and the upper reservoir are used as freshwater storage reservoirs. The upper reservoir has a height difference with the seawater desalination system, with a specific height range of 100-200m. The water level of the upper reservoir is 90-150m, the dead water level is 70-130m, and the regulating storage capacity is 200,000-500,000m 3 ;

[0022] (4) The installed capacity is 20-40MW, the energy storage pipeline specification is a pipeline diameter of 3m, and multiple longitudinally extending parallel to each other are connected to the turbine generator through a common pipeline. The multiple longitudinally extending parallel to each other pipelines are made of seawater corrosion-resistant material pipes, which are covered with marine concrete and fixed to the seabed.

[0023] A method for laying out a pumped storage power generation system based on desalinated seawater comprises the following steps:

[0024] (1) Site selection: Conduct surveys in coastal areas or islands and select a location with a lower reservoir depth of 600 m for construction. The ratio of the horizontal distance between the upper and lower reservoirs to their height, i.e., the distance-to-height ratio, should be between 3.0;

[0025] (2) A photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, and a seawater desalination system are provided, wherein the lower reservoir is installed on the seabed; the upper reservoir is installed near the coast and is higher than the seawater desalination system; the photovoltaic power generation system is provided near the coast; the wind power generation system is provided near the coast; the power system is electrically connected to the photovoltaic power generation system and the wind power generation system; the pumped storage system is provided between the lower reservoir and the upper reservoir; the input end of the seawater desalination system is electrically connected to the output end of the pumped storage system; at the same time, the output ends of the photovoltaic power generation system and the wind power generation system are also electrically connected to the input end of the seawater desalination system, and the seawater desalination system is powered by a portion of the electric energy generated by the photovoltaic power generation system and the wind power generation system, so that the seawater desalination system desalinates seawater; the output ends of the pumped storage system, the photovoltaic power generation system, and the wind power generation system are all connected to an external power supply system;

[0026] (3) Both the lower reservoir and the upper reservoir are used as freshwater storage reservoirs. The upper reservoir has a height difference of 150m from the seawater desalination system. The water level of the upper reservoir is 90m, the dead water level is 70m, and the regulating storage capacity is 300,000m 3 ;

[0027] (4) The installed capacity is 40MW, the energy storage pipeline specifications are 3m in diameter and 50m in length, with 10 longitudinally extending parallel to each other and connected to the turbine generator through a common pipeline. The multiple longitudinally extending parallel pipelines are FRP pipes made of seawater corrosion-resistant material, covered with marine concrete and fixed to the seabed, with a concrete thickness of 5m.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The pumped storage power generation system based on desalinated seawater is provided with a protection system. When the wind power generation system and the photovoltaic power generation system drive the power system to pump fresh water from the lower reservoir into the upper reservoir, the water flow impacts the turbine generator of the power system to rotate the turbine. The kinetic energy of the water flow is then converted into electrical energy through the generator to provide electrical energy for the gear pump, so that the gear pump delivers the lubricating oil in the oil tank of the oil supply system to the generators of each system, thereby avoiding the situation where the engine fails and the generator burns out. This solves the problem in the background technology that when the motor suddenly fails and there is no protection device, the generator will burn out, affecting the normal desalination of seawater.

[0030] 2. The present application ingeniously uses the energy conversion function of pumped storage to further improve the capacity conversion efficiency of pumped storage. At the same time, when the water level of the upper reservoir is too high, due to the height difference between the upper reservoir and the seawater desalination system, the flow regulation system can be used to convert the potential energy of the water in the upper reservoir into the rotational mechanical energy of the hydraulic turbine, and then the energy is transferred to the seawater desalination system through the energy conversion system, thereby driving the operation of the seawater desalination system. This design is a power supplement strategy for the photovoltaic power generation system and the wind power generation system. Under normal operating conditions, part of the electricity from the photovoltaic power generation system and the wind power generation system is used to power the seawater desalination system, so that the seawater desalination system desalinates seawater. The above-mentioned power supplement strategy can also be used to provide energy for the seawater desalination system by drawing fresh water from the upper reservoir, so that the desalination system maintains a high efficiency and obtains a stable fresh water output.

[0031] 3. This application proposes for the first time a strategy for replenishing electricity and water for a pumped-storage power generation system based on desalinated seawater, using a pumped-storage system disposed between the desalination system and the lower reservoir. The fresh water from the upper reservoir that flows through the desalination system and is used for power generation in the desalination system is discharged into the lower reservoir again through the pumped-storage system, realizing the fresh water storage function of the lower reservoir, while realizing the recycling of fresh water, protecting the internal power generation system from seawater corrosion, and can also be used for the water replenishment function when the water level of the upper reservoir is too low and there is a shortage of water. Among them, a pumped-storage system is also disposed between the desalination system and the lower reservoir, which can be connected to the upper reservoir and the lower reservoir through branch pipelines and share a pumped-storage system to complete the power generation function from water supply to water supply, thereby improving power generation efficiency and saving costs.

[0032] 4. This application proposes for the first time a pumped storage power generation system based on desalinated seawater, which realizes the recycling of fresh water and integrates power generation, water storage and desalination of seawater. The system realizes multiple power generation purposes and makes full use of coastal wind energy, light energy and seawater potential energy. On the basis of power generation during the water discharge process from the upper reservoir to the lower reservoir, this application cleverly captures the residual energy in various links and uses the energy captured in pumped storage for the power system and protection system. At the same time, the height difference between the upper reservoir and the desalination system is used to realize the conversion of the potential energy of the water in the upper reservoir into rotational mechanical energy, thereby driving the action of the seawater desalination system. This design is a power replenishment strategy for photovoltaic power generation systems and wind power generation systems. At the same time, it solves the problem of water resource waste caused by excessive water storage due to heavy rainfall in the upper reservoir, and truly recycles fresh water.

[0033] 5. The lower reservoir is installed on the seabed, and the upper reservoir is installed around the coast and higher than the desalination system. The lower reservoir and the upper reservoir are fresh water storage reservoirs. Pumped storage is achieved by using fresh water to reduce the corrosion of seawater to the pipeline. Each energy storage pipeline has a short distribution pipe at the end. Through these distribution pipes and energy storage pipelines, all energy storage pipelines are in communication and contact to form a large common lower reservoir. Each energy storage pipeline has a valve in the distribution pipe, which is particularly meaningful in the case of low energy generation or low energy demand. At the same time, this measure can optimize the working mode and efficiency of the underwater energy storage pipeline and improve the redundancy of the entire energy storage system. In addition, another advantage of setting up separate pipelines and valves is that if a certain energy storage pipeline fails, the energy storage pipeline can be closed separately, and each energy storage pipeline can be isolated from other energy storage pipelines in the system, which can avoid damage to the entire underwater energy storage pipeline.

[0034] 6. At present, no such power station has been built. In order to ensure the smooth operation and maintenance of the pilot work in the future, we evaluate from the construction needs and willingness, and choose a power plant with a not too large installed capacity, moderate power generation efficiency and the lowest cost. After our survey and calculation, we found that the water level of the upper reservoir is 90m, the dead water level is 70m, and the regulating storage capacity is 300,000 m 3 The lower reservoir is 600m deep, with a power generation efficiency of 80%, and the lowest static investment per kilowatt, which is 18,763 yuan / kW, close to the level of Zhoushan Taohua Island District of my country's seawater energy storage power station. It meets the national requirements for the construction cost of pumped storage power stations and also achieves the effect of cost saving.

[0035] 7. The present invention finds the optimal solution for the factors affecting the efficiency of pumped storage power generation through orthogonal design experiments: the depth of the lower reservoir is 600m, the distance-to-height ratio of the upper and lower reservoirs is 3, the installed capacity is 40MW, the energy storage pipeline specifications are 3m in diameter and 50m in length, and 3 longitudinal extensions are parallel to each other, and are connected and laid out through a common pipeline. This parameter is conducive to the efficiency of pumped storage power generation. The experiment shows that the order of influence of the factors affecting the efficiency of pumped storage power generation is: A (depth of the lower reservoir) > C (installed capacity) > D (energy storage pipeline specifications) > B (distance-to-height ratio of the upper and lower reservoirs). For cost considerations, although this experiment only uses 3 longitudinally extending parallel energy storage pipelines, it has significantly improved the power generation efficiency of the commonly used pumped storage caisson of the same volume. In particular, in the case of low energy generation or low energy demand, the use of this pipeline method is very effective, which can optimize the working mode and efficiency of the underwater energy storage pipeline and improve the redundancy of the entire energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0037] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0038] Figure 2 It is a schematic diagram of the structure of the protection system of the present invention;

[0039] Figure 3 It is a structural schematic diagram of the connection between the seawater desalination system and the lower reservoir of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] Example 1

[0043] A pumped storage power generation system based on desalinated seawater comprises a coast, a lower reservoir, an upper reservoir, a photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system and a seawater desalination system, wherein the lower reservoir is installed on the seabed; the upper reservoir is installed around the coast and higher than the seawater desalination system, the photovoltaic power generation system is arranged around the coast, the wind power generation system is arranged around the coast, the power system is electrically connected to the photovoltaic power generation system and the wind power generation system, the pumped storage system is arranged between the lower reservoir and the upper reservoir, the input end of the seawater desalination system is electrically connected to the output end of the pumped storage system; at the same time, the output ends of the photovoltaic power generation system and the wind power generation system are also electrically connected to the input end of the seawater desalination system, the seawater desalination system is powered by a part of the electric energy generated by the photovoltaic power generation system and the wind power generation system, so that the seawater desalination system desalinates seawater; the output ends of the pumped storage system, the photovoltaic power generation system and the wind power generation system are all connected to an external power supply system.

[0044] Example 2

[0045] See also Figure 1-Figure 2 , a pumped storage power generation system based on desalinated seawater, comprising a coast, a lower reservoir, an upper reservoir, a photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, a flow regulation system, an energy conversion system, a seawater desalination system, an oil supply system and a protection system, wherein the lower reservoir is installed on the seabed and is a submerged pipe or caisson or other water storage structure; the upper reservoir is installed around the coast and higher than the seawater desalination system, the photovoltaic power generation system is arranged around the coast, the wind power generation system is arranged around the coast, the power system is electrically connected to the photovoltaic power generation system and the wind power generation system, the pumped storage system is arranged between the lower reservoir and the upper reservoir, the flow regulation system is installed around the coast, the input end of the energy conversion system is electrically connected to the output end of the flow regulation system, the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system, a protection system is arranged between the lower reservoir and the upper reservoir, and the output end of the protection system is connected to the input end of the oil supply system;

[0046] The pumped storage system comprises a reversible turbine generator set, a flow pump, a pressure regulating device, and a water pipeline connecting the upper reservoir and the lower reservoir; when storing energy, offshore wind power or photovoltaic power or excess electricity on shore is used to drive the power system to drive the reversible turbine generator set of the pumped storage system to discharge water from the lower reservoir and transport it to the upper reservoir water storage tank at a high place, and convert the electrical energy into the potential energy of water for storage; when releasing energy, due to the internal and external pressure difference, the fresh water of the upper reservoir enters the lower reservoir from the high-position water storage tank, and drives the reversible pump turbine to generate electricity on the way, converting the potential energy of water into electrical energy, and this part of the electrical energy, as well as offshore wind power and photovoltaic power, are used for the external power supply system, or for supplementing the power of the seawater desalination system;

[0047] When the water level of the upper reservoir is too high, due to the height difference between the upper reservoir and the seawater desalination system, the flow regulating system can be used to convert the potential energy of the water in the upper reservoir into the rotational mechanical energy of the hydraulic turbine, and then the energy is transferred to the seawater desalination system through the energy conversion system, thereby driving the action of the seawater desalination system, that is, the input end of the energy conversion system is electrically connected to the output end of the flow regulating system, and the energy conversion system includes a hydraulic turbine, a transmission and a water tank; the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system; the output ends of the photovoltaic power generation system and the wind power generation system are electrically connected to the input end of the seawater desalination system, and the electric energy generated by a part of the photovoltaic power generation system and the wind power generation system is used to power the seawater desalination system, so that the seawater desalination system desalinates seawater;

[0048] The protection system includes a hydro-generator, a gearbox, and a gear pump; the oil supply system includes an oil tank, the generator is installed between the lower reservoir and the upper reservoir, the gearbox is connected to the output end of the generator, the gear pump is connected to the output end of the gearbox, and the oil tank is connected to the gear pump; when the wind power generation system and the photovoltaic power generation system drive the power system to pump water from the lower reservoir into the upper reservoir, the water flow impacts the hydro-generator of the protection system, causing the hydro-generator to rotate, converting the kinetic energy of the water flow into electrical energy, providing electrical energy for the gear pump, and causing the gear pump to deliver the lubricating oil in the oil tank into each system;

[0049] The wind power generation system includes: a variable pitch system, a converter system, an on-site touch screen station, an Ethernet switch, a field bus communication network, a UPS power supply and an emergency shutdown backup system; the photovoltaic power generation system includes a solar cell array, a battery pack, a charge and discharge controller, an inverter and an AC power distribution cabinet; the output ends of the photovoltaic power generation system and the wind power generation system are electrically connected to the input end of the seawater desalination system;

[0050] A pumped storage system is also provided between the desalination system and the lower reservoir. The fresh water from the upper reservoir that flows through the desalination system and is used for power generation in the desalination system is discharged into the lower reservoir again through the pumped storage system, thereby realizing the fresh water storage function of the lower reservoir and the recycling of fresh water, protecting the inside of the power generation system from being corroded by seawater. The pumped storage system can also be used for water replenishment when the water level in the upper reservoir is too low and there is a shortage of water.

[0051] Working principle: Photovoltaic power generation system and wind power generation system are used to convert light energy and wind energy into electrical energy to supply power to the power system. Then, the power system is used to pump fresh water from the lower reservoir into the upper reservoir, thereby raising the water level of the upper reservoir. The work done by the flow pump in the pumped storage system is converted into the fresh water potential energy of the upper reservoir. Then, the flow regulation system is used to adjust the water output of the upper reservoir. The energy conversion system is used to convert the potential energy of the water in the upper reservoir into the rotational mechanical energy of the hydraulic turbine, thereby driving the seawater desalination system to desalinate seawater. At the same time, part of the electricity generated by the photovoltaic power generation system and the wind power generation system can also supply power to the seawater desalination system, so that the seawater desalination system can desalinate seawater and improve the efficiency of seawater desalination. In the process of the power system pumping water from the lower reservoir into the upper reservoir, the water flow impacts the turbine connected to the hydro-generator, causing the hydro-generator to rotate, converting the kinetic energy of the water flow into electrical energy, providing electrical energy for the gear pump, so that the gear pump can deliver the lubricating oil in the oil tank to each system, thereby avoiding power failure of the engine and burning of the generator.

[0052] Embodiment 3:

[0053] Figure 3 As shown, on the basis of Example 2, a pumped storage system is further provided between the desalination system and the lower reservoir, which can also be connected to the upper reservoir and the lower reservoir through a branch pipeline and share a pumped storage system to complete the power generation function from the upper water to the lower water, thereby improving the power generation efficiency and saving costs. Specifically, a pumped storage system is further provided between the desalination system and the lower reservoir, and the fresh water flowing through the desalination system from the upper reservoir for power generation in the desalination system is discharged into the lower reservoir again through the pumped storage system, realizing the fresh water storage function of the lower reservoir, and realizing the recycling of fresh water at the same time, protecting the internal part of the power generation system from being corroded by seawater, and can also be used for the water replenishment function when the water level of the upper reservoir is too low and there is a shortage of water.

[0054] Example 4

[0055] A method for deploying a pumped storage power generation system based on desalinated seawater as in Example 1 comprises the following steps:

[0056] (1) Site selection: Conduct surveys in coastal areas or islands and select a location with a lower reservoir depth of 600 m for construction. The ratio of the horizontal distance between the upper and lower reservoirs to their height, i.e., the distance-to-height ratio, should be between 3.0;

[0057] (2) A photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, and a seawater desalination system are provided. The lower reservoir is installed on the seabed; the upper reservoir is installed near the coast and is higher than the seawater desalination system. The photovoltaic power generation system is provided near the coast; the wind power generation system is provided near the coast; the power system is electrically connected to the photovoltaic power generation system and the wind power generation system; the pumped storage system is provided between the lower reservoir and the upper reservoir; the input end of the seawater desalination system is electrically connected to the output end of the pumped storage system; at the same time, the output ends of the photovoltaic power generation system and the wind power generation system are also electrically connected to the input end of the seawater desalination system, and the electric energy generated by a part of the photovoltaic power generation system and the wind power generation system is used to power the seawater desalination system, so that the seawater desalination system desalinates seawater; the output ends of the pumped storage system, the photovoltaic power generation system, and the wind power generation system are all connected to an external power supply system (municipal power grid);

[0058] (3) Both the lower reservoir and the upper reservoir are used as freshwater storage reservoirs. The upper reservoir has a height difference of 150m from the seawater desalination system. The water level of the upper reservoir is 90m, the dead water level is 70m, and the regulating storage capacity is 300,000m 3 ;

[0059] (4) The installed capacity is 40MW, the energy storage pipeline specifications are 3m in diameter and 50m in length, with 10 pipelines extending longitudinally in parallel and connected to the turbine generator through a common pipeline. The multiple pipelines extending longitudinally in parallel are FRP pipes made of seawater corrosion-resistant material, which are covered with marine concrete and fixed to the seabed with a concrete thickness of 5m; each of the energy storage pipelines has a short distribution pipe at the end, and all the energy storage pipelines are in communication through these distribution pipes and the energy storage pipelines. Each energy storage pipeline has a valve in its distribution pipe, and each of these valves can be controlled individually.

[0060] Example 5

[0061] A method for deploying a pumped storage power generation system based on desalinated seawater as in Example 2 comprises the following steps:

[0062] (1) Site selection: Conduct surveys in coastal areas or islands and select a location with a lower reservoir depth of 600 m for construction. The ratio of the horizontal distance between the upper and lower reservoirs to their height, i.e., the distance-to-height ratio, should be between 3.0;

[0063] (2) A photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, a flow regulation system, an energy conversion system, a seawater desalination system, an oil supply system and a protection system are provided, wherein the lower reservoir is installed on the seabed, the flow regulation system, the photovoltaic power generation system and the wind power generation system are all provided around the coast, the power system is electrically connected to the photovoltaic power generation system and the wind power generation system, the pumped storage system is provided between the lower reservoir and the upper reservoir, the input end of the energy conversion system is electrically connected to the output end of the flow regulation system, the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system, a protection system is provided between the lower reservoir and the upper reservoir, and the output end of the protection system is connected to the input end of the oil supply system;

[0064] (3) Both the lower reservoir and the upper reservoir are used as freshwater storage reservoirs. The upper reservoir has a height difference of 150m from the seawater desalination system. The water level of the upper reservoir is 90m, the dead water level is 70m, and the regulating storage capacity is 300,000m 3 ;

[0065] (4) The installed capacity is 40MW, the energy storage pipeline specifications are 3m in diameter and 50m in length, with 10 longitudinally extending parallel to each other and connected to the turbine generator through a common pipeline. The multiple longitudinally extending parallel pipelines are FRP pipes made of seawater corrosion-resistant material, covered with marine concrete and fixed to the seabed, with a concrete thickness of 5m.

[0066] Experiment 1: Orthogonal test of factors affecting pumped storage power generation efficiency

[0067] Experimental method: The experimental site was selected in the Binhai New Area of ​​Tianjin. Based on the parameter summary of several pumped-storage power stations in Shantou City, Guangdong Province and Zhoushan City, Zhejiang Province that are under design, underwater test development and SAM software (mainly with two functions of power station performance prediction and economic analysis) model power generation test were carried out on 20MW and 40MW reversible turbine generators. Different specifications of submarine energy storage pipelines were used as the lower reservoir to simulate the power generation principle of the pumped-storage system. Submarine energy storage pipelines of different specifications were placed in the seabed at different depths as the lower reservoir for testing. When storing energy, offshore wind power or excess electricity (external power supply) was used to drive the reversible turbine generator (water pump) to pump out the water in the submarine energy storage pipeline and discharge it into the upper reservoir (fresh water). When releasing energy, due to the internal and external pressure difference (0.05 times the atmospheric pressure), the fresh water in the upper reservoir was put into the submarine energy storage pipeline again, and the reversible turbine was driven to generate electricity at the same time. This orthogonal experiment was designed according to the layout method of Example 4. Considering the experimental cost, we optimized the parameters and levels in advance. Through single factor analysis, we obtained the influence of different levels of different factors on pumped storage power generation, and obtained the following four important influencing factors: the depth of the lower reservoir A (level 1 is 300m, level 2 is 600m), the height ratio of the upper and lower reservoirs B (level 1 is 3, level 2 is 4.5), the installed capacity C (level 1 is 20MW, level 2 is 40MW), and the energy storage pipeline specification D (level 1 is a pipeline with a diameter of 3m and a length of 50m, with 3 parallel longitudinal extensions and connected by a common pipeline; level 2 is a commonly used pumped storage caisson with the same capacity as level 1). The four conditions are variables, and the optimal combination is selected, L8 (4 2 ) Orthogonal table. According to the factors and levels in Table 1, the experiment was conducted with 8 treatments. The power generation efficiency was calculated as the evaluation index. The calculation formula for the power generation efficiency of the generator was: power generation efficiency = output power / input power × 100%.

[0068] Table 1 Orthogonal test of factors affecting pumped storage power generation efficiency

[0069]

[0070]

[0071] Experimental results: From the table above, it can be seen that the optimal solution of the orthogonal test of factors affecting pumped storage power generation efficiency is A2B1C2D1, that is, the depth of the lower reservoir is 600m, the distance-to-height ratio of the upper and lower reservoirs is 3, the installed capacity is 40MW, and the energy storage pipeline specifications are 3m in diameter and 50m long, with 3 longitudinal extensions parallel to each other and connected by a common pipeline. This parameter is conducive to the efficiency of pumped storage power generation. The experiment shows that the order of influence of the factors affecting the efficiency of pumped storage power generation is: A (depth of the lower reservoir) > C (installed capacity) > D (storage pipeline specifications) > B (distance-to-height ratio of the upper and lower reservoirs).

[0072] For cost considerations, although this experiment only used three longitudinally extending parallel energy storage pipelines, its power generation efficiency has been significantly improved compared with the commonly used pumped-storage caissons of the same volume. In particular, in the case of low energy generation or low energy demand, the use of this pipeline method is very effective, which can optimize the working mode and efficiency of the underwater energy storage pipeline and improve the redundancy of the entire energy storage system.

[0073] Experiment 2: Analysis of technical indicators of construction cost of pumped storage power station

[0074] Experimental method: Through years of research, we have further derived several key technical indicators that affect the construction cost of pumped storage power stations. Through preliminary investigation, design and cost calculation, combined with power generation effect evaluation, this experiment mainly analyzes the technical indicators of pumped storage power station construction cost, and uses the economic analysis model of SAM software to obtain the best implementation plan. At present, there is no such power station built in my country. In order to ensure the smooth operation and maintenance of pilot work in the future, the installed capacity should not be too large, the power generation efficiency should be moderate and the cost should be the lowest. The installed capacity of this study is uniformly calculated as 40MW. The pipeline of the lower reservoir is selected with a diameter of 3m and a length of 50m. 10 pipelines are connected in parallel through a common pipeline. The pipelines are all made of seawater corrosion-resistant material FRP pipes, covered with marine concrete and fixed on the seabed. The concrete thickness is 5m. The reference parameters of the inlet / outlet of the upper and lower reservoirs are 72.99*10m 3 / s, inflow (pumping) 52.59*10m 3 / s. Among them, test examples 9-13 are calculated according to the layout of the upper and lower reservoirs of the pumped storage power generation system of embodiment 5 of the present application, and the installed capacity of the wind power generation and photovoltaic power generation systems are both 40MW. Test example 14 is calculated according to the layout of the upper and lower reservoirs of the pumped storage power generation system of embodiment 4 of the present application, and the designs of the flow regulation system, energy conversion system, oil supply system and protection system are omitted.

[0075] Table 2 Analysis of construction cost technical indicators of freshwater pumped storage power station

[0076]

[0077] Experimental results: There is no such power station built yet. In order to ensure the smooth operation and maintenance of the pilot work in the future, we evaluate from the construction needs and willingness, and choose a power plant with a not too large installed capacity, moderate power generation efficiency and the lowest cost. After our survey and calculation, we found that the water level of the upper reservoir is 90m, the dead water level is 70m, and the regulating storage capacity is 300,000 m 3, the depth of the lower reservoir is 600m, the power generation efficiency is 80%, and the static investment per kilowatt is the lowest, which is 18763 yuan / kW, close to the level of the Taohua Island area of ​​Zhoushan, my country's seawater energy storage power station, that is, it meets the national requirements for the construction cost of pumped storage power stations, and also achieves the effect of cost saving. When we increase the depth of the lower reservoir, that is, through single factor analysis, it is concluded that 600-800m is suitable for the establishment of a pumped storage power station, but while the power generation efficiency is significantly improved by increasing the depth of the lower reservoir, its static investment cost per kilowatt is also significantly increased. Therefore, this study can significantly improve the power generation efficiency at a depth of 600m in the lower reservoir, and can provide basic research for the establishment of a freshwater pumped storage power station in the future. From the simulation calculation of Test Example 14, it is found that if the design of the flow regulation system, energy conversion system, oil supply system and protection system of the present invention is omitted, the capacity conversion efficiency of pumped storage during pumping and the power generation efficiency when the flow regulation is converted to the power replenishment strategy of the desalination system will not be taken into account, and its power generation efficiency will be significantly reduced.

[0078] Experiments show that the present application ingeniously uses the energy conversion function of pumped storage to further improve the capacity conversion efficiency of pumped storage. At the same time, when the water level of the upper reservoir is too high, due to the height difference between the upper reservoir and the seawater desalination system, the flow regulation system can be used to convert the potential energy of the water in the upper reservoir into the rotational mechanical energy of the hydraulic turbine, and then the energy is transferred to the seawater desalination system through the energy conversion system, thereby driving the operation of the seawater desalination system. This design is a power replenishment strategy for the power generation system. Under normal operating conditions, part of the electricity from the photovoltaic power generation system and the wind power generation system is used to power the seawater desalination system, so that the seawater desalination system desalinates seawater. The above-mentioned power replenishment strategy can also be used to provide energy for the seawater desalination system by drawing fresh water from the upper reservoir, so that the desalination system maintains a high efficiency and obtains a stable fresh water output.

[0079] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0080] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pumped storage power generation system based on desalinated seawater, characterized in that: It includes a coast, a lower reservoir, an upper reservoir, a photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, a flow regulation system, an energy conversion system, a seawater desalination system, an oil supply system and a protection system. The lower reservoir is installed on the seabed and is a immersed tube or caisson or other water storage structure; the upper reservoir is installed around the coast and higher than the seawater desalination system, the photovoltaic power generation system is arranged around the coast, the wind power generation system is arranged around the coast, the power system is electrically connected to the photovoltaic power generation system and the wind power generation system, the pumped storage system is arranged between the lower reservoir and the upper reservoir, the input end of the energy conversion system is electrically connected to the output end of the flow regulation system, the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system, a protection system is arranged between the lower reservoir and the upper reservoir, and the output end of the protection system is connected to the input end of the oil supply system.

2. A pumped storage power generation system based on desalinated seawater according to claim 1, characterized in that: The pumped storage system comprises a reversible turbine generator set, a flow pump, a pressure regulating device, and a water pipeline connecting the upper reservoir and the lower reservoir. When storing energy, offshore wind power or photovoltaic power or excess electricity on shore is used to drive the power system to drive the reversible turbine generator set of the pumped storage system to discharge water from the lower reservoir and transport it to the upper reservoir water tank at a high place, convert the electrical energy into the potential energy of water and store it, so that the air pressure of the lower reservoir is 0.05-0.10 times the atmospheric pressure. When releasing energy, due to the internal and external pressure difference, the fresh water of the upper reservoir enters the lower reservoir from the high-position water tank, and drives the reversible pump turbine to generate electricity on the way, converting the potential energy of water into electrical energy. This part of the electrical energy, as well as offshore wind power and photovoltaic power, can be used for an external power supply system, or for supplementing the power of a seawater desalination system.

3. A pumped storage power generation system based on desalinated seawater according to claim 2, characterized in that: When the water level of the upper reservoir is too high, due to the height difference between the upper reservoir and the seawater desalination system, the flow regulation system can be used to convert the potential energy of the water in the upper reservoir into the rotational mechanical energy of the hydraulic turbine, and then the energy is transferred to the seawater desalination system through the energy conversion system, thereby driving the action of the seawater desalination system, that is, the input end of the energy conversion system is electrically connected to the output end of the flow regulation system, and the energy conversion system includes a hydraulic turbine, a transmission and a water tank; the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system, that is, this process can be used to supplement the power of the seawater desalination system; the output ends of the photovoltaic power generation system and the wind power generation system are electrically connected to the input end of the seawater desalination system, and part of the electric energy generated by the photovoltaic power generation system and the wind power generation system can also be used to power the seawater desalination system, so that the seawater desalination system desalinates seawater.

4. A pumped storage power generation system based on desalinated seawater according to claim 1, characterized in that: The protection system includes a hydro-turbine generator, a gearbox, and a gear pump; the oil supply system includes an oil tank, the generator is installed between the lower reservoir and the upper reservoir, the gearbox is connected to the output end of the generator, the gear pump is connected to the output end of the gearbox, and the oil tank is connected to the gear pump; in the process of the wind power generation system and the photovoltaic power generation system driving the power system to pump water from the lower reservoir into the upper reservoir, the water flow impacts the hydro-turbine generator of the protection system, causing the hydro-turbine generator to rotate, converting the kinetic energy of the water flow into electrical energy, providing electrical energy for the gear pump, and causing the gear pump to deliver the lubricating oil in the oil tank into each system.

5. A pumped storage power generation system based on desalinated seawater according to claim 1, characterized in that: The wind power generation system includes: a variable pitch system, a converter system, an on-site touch screen station, an Ethernet switch, a field bus communication network, a UPS power supply and an emergency shutdown backup system; the photovoltaic power generation system includes a solar cell array, a battery pack, a charge and discharge controller, an inverter and an AC distribution cabinet; the output ends of the photovoltaic power generation system and the wind power generation system are electrically connected to the input end of the seawater desalination system.

6. A pumped storage power generation system based on desalinated seawater according to claim 1, characterized in that: Another pumped storage system is also arranged between the desalination system and the lower reservoir. The fresh water from the upper reservoir that flows through the desalination system and is used for power generation in the desalination system is discharged into the lower reservoir again through the pumped storage system, thereby realizing the fresh water storage function of the lower reservoir and the recycling of fresh water, protecting the internal part of the power generation system from being corroded by seawater. It can also be used for water replenishment when the water level in the upper reservoir is too low and there is a shortage of water.

7. A pumped storage power generation system based on desalinated seawater according to claim 6, characterized in that: Another pumped storage system is also arranged between the seawater desalination system and the lower reservoir, which can also be connected to the water pipeline between the upper reservoir and the lower reservoir through a branch pipeline and share a pumped storage system to complete another power generation function from water supply to water discharge, thereby improving power generation efficiency and saving costs.

8. A pumped storage power generation system based on desalinated seawater according to claim 1, characterized in that: The underwater depth of the lower reservoir is 400-800m, and the ratio of the horizontal distance to the height of the upper and lower reservoirs, i.e. the distance-to-height ratio, is between 3.0-4.

5. The lower reservoir is a plurality of energy storage pipelines with a specification of a pipeline diameter of 3m. Multiple longitudinally extending pipelines are parallel to each other and connected to the reversible turbine generator through a common pipeline. The multiple longitudinally extending parallel pipelines are made of seawater corrosion-resistant material pipes, which are covered with marine concrete and fixed to the seabed.

9. A method for laying out a pumped storage power generation system based on desalinated seawater according to claim 1, characterized in that: The steps include: (1) Site selection: Conduct surveys in coastal areas or islands and select a location with a lower reservoir depth of 400-800 m for construction. The ratio of the horizontal distance between the upper and lower reservoirs to their height, i.e., the distance-to-height ratio, should be between 3.0 and 4.5; (2) A photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, a flow regulation system, an energy conversion system, a seawater desalination system, an oil supply system and a protection system are provided, wherein the lower reservoir is installed on the seabed, the flow regulation system, the photovoltaic power generation system and the wind power generation system are all provided around the coast, the power system is electrically connected to the photovoltaic power generation system and the wind power generation system, the pumped storage system is provided between the lower reservoir and the upper reservoir, the input end of the energy conversion system is electrically connected to the output end of the flow regulation system, the input end of the seawater desalination system is electrically connected to the output end of the energy conversion system, a protection system is provided between the lower reservoir and the upper reservoir, and the output end of the protection system is connected to the input end of the oil supply system; (3) Both the lower reservoir and the upper reservoir are used as freshwater storage reservoirs. The upper reservoir has a height difference with the seawater desalination system, with a specific height range of 100-200m. The water level of the upper reservoir is 90-150m, the dead water level is 70-130m, and the regulating storage capacity is 200,000-500,000m 3 ; (4) The installed capacity is 20-40MW, the energy storage pipeline specification is a pipeline diameter of 3m, and multiple pipelines are arranged longitudinally and parallel to each other, and are connected to the turbine generator through a common pipeline. The multiple pipelines extending longitudinally and parallel to each other are made of seawater corrosion-resistant material pipes, which are covered with marine concrete and fixed to the seabed; each end of the energy storage pipeline has a short distribution pipe, and through these distribution pipes and the energy storage pipeline, all the energy storage pipelines are in communication and contact, and each energy storage pipeline has a valve in the distribution pipe, and each of these valves can be controlled individually.

10. A method for laying out a pumped storage power generation system based on desalinated seawater, characterized in that: The steps include: (1) Site selection: Conduct surveys in coastal areas or islands and select a location with a lower reservoir depth of 400-800 m for construction. The ratio of the horizontal distance between the upper and lower reservoirs to their height, i.e., the distance-to-height ratio, should be between 3.0 and 4.5; (2) A photovoltaic power generation system, a wind power generation system, a power system, a pumped storage system, and a seawater desalination system are provided, wherein the lower reservoir is installed on the seabed; the upper reservoir is installed near the coast and is higher than the seawater desalination system; the photovoltaic power generation system is provided near the coast; the wind power generation system is provided near the coast; the power system is electrically connected to the photovoltaic power generation system and the wind power generation system; the pumped storage system is provided between the lower reservoir and the upper reservoir; the input end of the seawater desalination system is electrically connected to the output end of the pumped storage system; at the same time, the output ends of the photovoltaic power generation system and the wind power generation system are also electrically connected to the input end of the seawater desalination system, and the seawater desalination system is powered by a portion of the electric energy generated by the photovoltaic power generation system and the wind power generation system, so that the seawater desalination system desalinates seawater; the output ends of the pumped storage system, the photovoltaic power generation system, and the wind power generation system are all connected to an external power supply system; (3) Both the lower reservoir and the upper reservoir are used as freshwater storage reservoirs. The upper reservoir has a height difference with the seawater desalination system, with a specific height range of 100-200m. The water level of the upper reservoir is 90-150m, the dead water level is 70-130m, and the regulating storage capacity is 200,000-500,000m 3 (4) The installed capacity is 20-40MW, the energy storage pipeline specifications are 3m in diameter and 50m in length, 3-10 pipelines are arranged in parallel and longitudinally extend in parallel to each other, and are connected to the turbine generator through a common pipeline. The multiple longitudinally extending parallel pipelines are FRP pipes made of seawater corrosion-resistant material, which are covered with marine concrete and fixed to the seabed with a concrete thickness of 5m; each end of the energy storage pipeline has a short distribution pipe, through which all the energy storage pipelines are in communication and contact, and each energy storage pipeline has a valve in the distribution pipe, each of which can be controlled individually.

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