Offshore wind farm multi-energy complementary operation system and method

Abstract

The application provides a kind of offshore wind farm multi-energy complementary operation system and method, belong to offshore wind farm technical field. Among them, the system of the application includes: offshore wind farm, the offshore wind farm provides electric energy to power grid;Seawater desalination device, the seawater desalination device utilizes the residual electric energy of the offshore wind farm to produce fresh water from seawater;Coastal thermal power plant, the coastal thermal power plant utilizes the fresh water to generate electricity, and supplements electric energy to the power grid.The application forms regional comprehensive energy system with large offshore wind farm, seawater desalination system and coastal thermal power plant, improves the operation flexibility of offshore wind farm, meets the maximization of wind energy utilization through multi-energy complementary strategy. And, regional comprehensive energy system is accessed to power side nearby, reduces long-distance transmission loss.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of offshore wind farms, and particularly relates to a multi-energy complementary operation system and method for offshore wind farms. BACKGROUND

[0002] The rapid development of science and technology has made the marine economy a focus of the world. Studies have shown that offshore wind speed is often more stable than land wind speed, which means that the reliability of offshore wind power technology is higher than that of land wind farms. In addition, China's coastline is 18,000 kilometers long, and the available sea area is more than 3 million square kilometers. The rich offshore wind energy resources make it a natural advantage to develop offshore wind power. Vigorously developing offshore wind power, offshore photovoltaic and other marine energy economies is an important foothold for building a resource-saving and environment-friendly society. In terms of social impact, water crisis is considered the fourth global risk. Seawater desalination is an intelligent and promising technology to solve the crisis of freshwater resources. Therefore, combining offshore wind farms, seawater desalination systems, and coastal thermal power plants to build a small-scale integrated energy system is a practical solution to improve energy utilization.

[0003] Therefore, the present application provides a multi-energy complementary operation system and method for offshore wind farms. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a multi-energy complementary operation system and method for offshore wind farms.

[0005] In one aspect of the present application, a multi-energy complementary operation system for offshore wind farms is provided, comprising:

[0006] an offshore wind farm, which provides electric energy to a power grid;

[0007] a seawater desalination device, which uses the remaining electric energy of the offshore wind farm to produce freshwater from seawater;

[0008] a coastal thermal power plant, which uses the freshwater to generate electricity and supplements the electric energy to the power grid.

[0009] Optionally, the system further comprises an electric energy collection and dispatching system for coordinating and dispatching the offshore wind farm, the seawater desalination device, and the coastal thermal power plant.

[0010] Optionally, the electric energy collection and dispatching system comprises a first judgment module and a first dispatching module; wherein,

[0011] the first judgment module is configured to judge whether the supply of electric energy of the offshore wind farm meets the load of the power grid;

[0012] The first scheduling module is configured to, in response to the load instruction of the power grid being less than the real-time power generation of the offshore wind farm, provide the offshore wind farm with power according to the instruction power to the power grid.

[0013] Optionally, the power aggregation and scheduling system further comprises a second judging module and a second scheduling module, wherein,

[0014] The second judging module is configured to judge whether the offshore wind farm has surplus power.

[0015] The second scheduling sub-module is configured to, in response to the offshore wind farm having surplus power, provide the surplus power to the seawater desalination device.

[0016] Optionally, the power aggregation and scheduling system further comprises a third scheduling module, configured to, in response to the load instruction of the power grid being greater than the real-time power generation of the offshore wind farm, provide the coastal thermal power plant with power to the power grid.

[0017] In another aspect of the present application, a method for multi-energy complementary operation of an offshore wind farm is provided, comprising the following steps:

[0018] The offshore wind farm provides power to the power grid.

[0019] The seawater desalination device produces fresh water from seawater by using the surplus power of the offshore wind farm.

[0020] The coastal thermal power plant generates power by using the fresh water and provides power to the power grid.

[0021] Optionally, the method further comprises: coordinating and scheduling the offshore wind farm, the seawater desalination device and the coastal thermal power plant.

[0022] Optionally, the coordinating and scheduling of the offshore wind farm, the seawater desalination device and the coastal thermal power plant comprises:

[0023] Judging whether the power supply of the offshore wind farm meets the load of the power grid.

[0024] In response to the load instruction of the power grid being less than the real-time power generation of the offshore wind farm, the offshore wind farm provides power according to the instruction power to the power grid.

[0025] Optionally, the coordinating and scheduling of the offshore wind farm, the seawater desalination device and the coastal thermal power plant further comprises:

[0026] Judging whether the offshore wind farm has surplus power.

[0027] In response to the surplus of the electric energy of the offshore wind farm, the surplus electric energy is provided to the seawater desalination device.

[0028] Optionally, the collaborative scheduling of the offshore wind farm, the seawater desalination device and the coastal thermal power plant further includes:

[0029] In response to the load instruction of the power grid being greater than the real-time power generation of the offshore wind farm, the coastal thermal power plant supplements the electric energy to the power grid.

[0030] The present application provides a kind of offshore wind farm multi-energy complementary operation system, comprising: offshore wind farm, the offshore wind farm provides electric energy to power grid;Seawater desalination device, the seawater desalination device utilizes the electric energy from seawater production fresh water of the surplus of the offshore wind farm;Coastal thermal power plant, the coastal thermal power plant utilizes the fresh water and generates electricity, and supplements the electric energy to the power grid.The present application will large offshore wind farm, seawater desalination system and coastal thermal power plant are organized regional integrated energy system, improve the operation flexibility of offshore wind farm, through multi-energy complementary strategy, the maximization of wind energy is met.And, regional integrated energy system is accessed to power side nearby, reduces long-distance transmission loss. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 For an embodiment of the present application, a kind of offshore wind farm multi-energy complementary operation system structure schematic view;

[0032] Figure 2 For another embodiment of the present application, seawater distillation process schematic view;

[0033] Figure 3 For another embodiment of the present application, offshore wind farm multi-energy complementary operation method flow chart. DETAILED DESCRIPTION

[0034] To make those skilled in the art better understand the technical solutions of the present application, the present application will be further described in detail below in conjunction with the drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0035] As Figure 1As shown, in one aspect of the present application, a multi-energy complementary operation system 100 of offshore wind farm is provided, comprising: an offshore wind farm 110, a seawater desalination device 120 and a coastal thermal power plant 130. Wherein the offshore wind farm 110 provides electric energy to the power grid 140; the seawater desalination device 120 uses the residual electric energy of the offshore wind farm 110 to produce fresh water from seawater; and the coastal thermal power plant 130 uses the fresh water to generate electricity and supplement the electric energy to the power grid 140.

[0036] It should be noted that the clean transformation of energy structure and the rich offshore wind energy resources promote the development of offshore wind power technology in countries around the world. Offshore wind power and land wind power are similar, both of which use wind energy to drive wind turbine blades to rotate and generate electricity. Compared with land wind power, offshore wind power has the advantages of being located in the load center, stable energy supply and good power quality, so its installed capacity is gradually expanding. The development space of offshore wind power in China is broad and the potential is huge. Accelerating the development of offshore wind power technology is of great significance to promote the safe, clean and efficient transformation of China's energy structure.

[0037] Based on this, the present example proposes to establish an offshore wind farm at sea to utilize the offshore wind energy resources to generate electricity to supply power to the power grid.

[0038] Further, seawater desalination is a technology for producing fresh water by desalting seawater. Using seawater desalination technology can alleviate the global water resource shortage, realize the open-source incremental exploitation of water resources, and ensure stable water supply for coastal residents' drinking water and industrial boiler water supply. Common seawater desalination methods include electrodialysis, distillation and seawater freezing. Based on the power supply provided by the offshore wind farm, the present application will use the distillation method to desalinate seawater to maximize fresh water production and reduce energy consumption and performance ratio.

[0039] The distillation process is carried out with the help of a heat source, which evaporates the water molecules in the seawater, separates them from the salt particles, and finally obtains distilled water vapor and salt water, as shown in Figure 2 .

[0040] As can be seen from Figure 2 , the seawater feed liquid is injected into the evaporator with heat source supply by the seawater lifting pump. Then heated by the high-temperature heat source, the seawater exchanges heat with the heat recovery section, a part of the seawater is vaporized into water vapor (available fresh water) due to the absorption of latent heat of condensing steam in the evaporator, and the other part of the salt-containing seawater is discharged into the sea.

[0041] Based on this, the present embodiment also establishes a seawater desalination device at sea to effectively utilize the electric energy to produce fresh water in seawater.

[0042] Further, compared with inland coal, overseas coal has higher competitiveness, so it attracts a batch of coastal coal-fired power plants to be put into production. In addition, coastal coal-fired power plants are large water users, and their water consumption accounts for about 40% of industrial water consumption. Stable and sufficient water resource supply is the premise for the safe, economic and stable operation of power plants. The feedwater control system of thermal power plants mainly stabilizes the boiler water ratio in the constant power generation process by stabilizing the outlet temperature of the separator, so as to control the boiler steam temperature and pressure. The water control system meets the water demand of the unit under different working conditions.

[0043] Based on this, the embodiment also establishes a coastal thermal power plant to generate power by using the fresh water generated by the seawater desalination device and supply power to the power grid.

[0044] It should be understood that the above three systems form a regional integrated energy system, and the large randomness of offshore wind energy seriously affects the market share of China's offshore wind farms in the power market. Under the background of clean and efficient transformation of energy, regional energy systems will become the future development trend. In order to improve the stability of the power system under large-scale offshore wind power grid connection, the present application proposes an integrated energy system architecture integrating large-scale offshore wind farms, seawater desalination systems and coastal thermal power plants.

[0045] The system of the embodiment also includes an electric energy aggregation and dispatching system for coordinating and dispatching the offshore wind farm, the seawater desalination device and the coastal thermal power plant.

[0046] Specifically, the electric energy aggregation and dispatching system includes a first judgment module and a first dispatching module; wherein the first judgment module is used to judge whether the supply of electric energy of the offshore wind farm meets the load of the power grid; the first dispatching module is used to provide electric energy to the power grid according to the instruction electric quantity when the load instruction of the power grid is less than the real-time power generation of the offshore wind farm.

[0047] Further, the electric energy aggregation and dispatching system of the embodiment also includes a second judgment module and a second dispatching module; wherein the second judgment module is used to judge whether the electric energy of the offshore wind farm has surplus; the second dispatching sub-module is used to provide the surplus electric energy to the seawater desalination device when the electric energy of the offshore wind farm has surplus.

[0048] Further, the electric energy aggregation and dispatching system of the embodiment also includes a third dispatching module, which is used to supplement the electric energy to the power grid when the load instruction of the power grid is greater than the real-time power generation of the offshore wind farm.

[0049] To improve the consumption of renewable energy power, the large-scale wind farm of the comprehensive energy system is always in full load generation state, and the seawater desalination system and the coastal thermal power plant are used as auxiliary power supply equipment. When the load instruction of the power grid is less than the real-time power generation of the offshore wind farm, the wind farm supplies the power grid with the instructed power. The remaining power of the wind farm is supplied to the seawater desalination device as a heat source for distilling seawater to produce fresh water. The fresh water produced by the seawater desalination device is supplied to the boiler of the nearby thermal power plant to meet the requirement of constant water consumption and ensure the stable and economical operation of the unit. When the load instruction of the power grid is greater than the real-time power generation of the offshore wind farm, the power generated by the wind farm is supplied to the power grid. At the same time, the thermal power plant quickly increases the load to generate power to supplement the required power of the power grid. Through the cooperation and complementation of the offshore wind farm, the seawater desalination device and the coastal thermal power plant, the operation flexibility of the large-scale offshore wind farm and the thermal power plant is improved, and the goal of clean and efficient energy utilization is achieved.

[0050] As shown in Figure 3 Another aspect of the present application provides a method S200 for multi-energy complementary operation of an offshore wind farm, comprising the following specific steps S210-S230:

[0051] S210, the offshore wind farm provides electric energy to the power grid.

[0052] S220, the seawater desalination device produces fresh water from seawater using the remaining electric energy of the offshore wind farm.

[0053] S230, the coastal thermal power plant generates power using the fresh water and supplements the electric energy to the power grid.

[0054] Further, the method of the present embodiment further comprises: coordinating and scheduling the offshore wind farm, the seawater desalination device and the coastal thermal power plant.

[0055] Specifically, in some embodiments, the coordination and scheduling of the offshore wind farm, the seawater desalination device and the coastal thermal power plant comprises: judging whether the electric energy supplied by the offshore wind farm meets the load of the power grid; and in response to the load instruction of the power grid being less than the real-time power generation of the offshore wind farm, the offshore wind farm provides electric energy to the power grid according to the instructed power.

[0056] Further, in another embodiment, the coordination and scheduling of the offshore wind farm, the seawater desalination device and the coastal thermal power plant further comprises: judging whether the electric energy of the offshore wind farm has a surplus; and in response to the electric energy of the offshore wind farm having a surplus, providing the surplus electric energy to the seawater desalination device.

[0057] Further, in some embodiments, the offshore wind farm, the seawater desalination device, and the coastal thermal power plant are cooperatively scheduled, and the method further comprises: in response to the load instruction of the power grid being greater than the real-time power generation of the offshore wind farm, the coastal thermal power plant supplements the power grid with electric energy.

[0058] The offshore wind farm multi-energy complementary operation system and method will be described below with specific embodiments:

[0059] Based on the historical operation data of a certain 41x7 large-scale offshore wind farm, simulation experiments are carried out.

[0060] I. Establishing an offshore wind farm model

[0061] Similar to land-based wind power, offshore wind power uses wind energy to drive wind turbine blades to rotate and generate electricity. Compared with land-based wind power, offshore wind power has the advantages of being located in the load center, stable energy supply, and good power quality, so its installed capacity is gradually expanding. Based on the past 7 days of operation data of the large-scale offshore wind farm, a mathematical model is established.

[0062] II. Designing a seawater desalination system

[0063] Seawater desalination is a technology that produces fresh water by desalinating seawater. Using seawater desalination technology can alleviate the global water resource shortage, realize water resource exploitation, and ensure stable water supply for coastal residents' drinking water and industrial boiler water supply. Common methods of seawater desalination include electrodialysis, distillation, and seawater freezing. Based on the power supply provided by the offshore wind farm, the invention will use the distillation method to desalinate seawater to maximize fresh water production and reduce energy consumption and performance ratio. Combined with the model of the wind farm and the historical wind curtailment data, a seawater desalination plant of appropriate scale is designed to complement each other in operation.

[0064] The distillation process is carried out with the help of a heat source, which evaporates the water molecules in the seawater, separates them from the salt particles, and finally obtains distilled water vapor and salt water, as shown in Figure 2 The seawater feed liquid is injected into the evaporator with a heat source supply by the seawater lifting pump. Then, after being heated by the high-temperature heat source, the seawater exchanges heat with the heat recovery section, a part of the seawater is vaporized into water vapor (available fresh water) due to the absorption of latent heat of condensing steam in the evaporator, and the other part of the salt-containing seawater is discharged into the sea.

[0065] III. Configuring a coastal thermal power plant

[0066] Stable and sufficient water resource supply is the premise of safe, economic and stable operation of power plants. The water supply control system of thermal power plants mainly stabilizes the outlet temperature of the separator to achieve a constant boiler water ratio in the power generation process, thereby controlling the boiler steam temperature and pressure. The water control system meets the water demand of the unit under different working conditions. Based on the historical power generation capacity of the wind farm and the scale of the seawater desalination system, a coastal thermal power plant that meets the load demand is configured. When the wind energy is insufficient, the power grid's demand for electricity from the comprehensive energy system is met by the thermal power plant.

[0067] Four, regional comprehensive energy system architecture

[0068] The randomness of offshore wind energy has seriously affected the market share of China's offshore wind farms. In the context of clean and efficient energy transformation, regional energy systems will be the future trend. To improve the stability of the power system under large-scale offshore wind power integration, the present invention proposes an integrated comprehensive energy system architecture that integrates large-scale offshore wind farms, seawater desalination systems and coastal thermal power plants, as shown in Figure 1 .

[0069] The large-scale offshore wind farm, seawater desalination system and coastal thermal power plant are configured within a small regional range, and the multi-energy complementary scheme of the comprehensive energy system shown in Figure 1 is implemented. To improve the consumption of renewable energy power, the large-scale wind farm of the comprehensive energy system is always in full load generation, and the seawater desalination system and coastal thermal power plant serve as auxiliary power supply equipment. When the load instruction of the power grid is less than the real-time power generation of the offshore wind farm, the wind farm supplies the power grid with the instructed power. The remaining power of the wind farm is used as a heat source to supply the seawater desalination device for distilling seawater to produce fresh water. The fresh water produced by the seawater desalination device is supplied to the boiler of the nearby thermal power plant to meet its constant demand for water ratio, ensuring the economic and stable operation of the unit. When the load instruction of the power grid is greater than the real-time power generation of the offshore wind farm, the power generated by the wind farm is entirely supplied to the power grid. At the same time, the thermal power plant quickly increases the load to generate power to supplement the power grid's demand for electricity from the entire comprehensive energy system. Through the cooperation and complementation of offshore wind farms, seawater desalination devices and coastal thermal power plants, the operation flexibility of large-scale offshore wind farms and thermal power plants is improved, and the goal of clean and efficient energy utilization is achieved.

[0070] The present invention provides a multi-energy complementary operation system and method for offshore wind farms, which has the following advantages over the prior art:

[0071] First, the present invention integrates large-scale offshore wind farms, seawater desalination systems and coastal thermal power plants into a regional comprehensive energy system, improving the operation flexibility of offshore wind farms.

[0072] Second, the present invention meets the maximum utilization of wind energy through multi-energy complementary strategies.

[0073] Third, the present application accesses the regional integrated energy system to the power side nearby, and configures large offshore wind farms, coastal thermal power plants and seawater desalination plants nearby, thereby reducing long-distance power transmission loss.

[0074] It can be understood that the above embodiments are only exemplary embodiments for illustrating the principles of the present application, and the present application is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered to be within the protection scope of the present application.

Claims

1. A multi-energy complementary operation system for offshore wind farms, characterized in that, include: Offshore wind farms that supply electricity to the power grid; A seawater desalination device that uses surplus electricity from the offshore wind farm to produce fresh water from seawater; A coastal thermal power plant that uses the freshwater to generate electricity and supplies power to the grid; The power aggregation and dispatch system includes a first judgment module and a first dispatch module, a second judgment module and a second dispatch module, and a third dispatch module; wherein, The first judgment module is used to determine whether the power supply of the offshore wind farm meets the load of the power grid; The first scheduling module is used to respond to the situation where the load command of the power grid is less than the real-time power generation of the offshore wind farm, and the offshore wind farm provides power to the power grid according to the commanded power. The second judgment module is used to determine whether there is any remaining electrical energy in the offshore wind farm; The second scheduling module is used to provide the surplus electrical energy to the seawater desalination unit when there is surplus electrical energy in the offshore wind farm, and the fresh water produced by the seawater desalination unit is supplied to the boiler of a nearby thermal power plant. The third dispatch module is used to respond to the load command of the power grid being greater than the real-time power generation of the offshore wind farm, so that the coastal thermal power plant can supplement the power grid with electricity, and at the same time, the coastal thermal power plant can quickly increase its load to generate electricity to supplement the power grid's demand on the entire integrated energy system. The offshore wind farm is always operating at full capacity, while the seawater desalination plant and the coastal thermal power plant serve as auxiliary power supply equipment.

2. A method for multi-energy complementary operation of an offshore wind farm, characterized in that, Includes the following steps: Offshore wind farms supply electricity to the power grid; The seawater desalination unit uses the surplus electricity from the offshore wind farm to produce fresh water from seawater; Coastal thermal power plants utilize the freshwater to generate electricity and supplement the power grid. Coordinated scheduling of the offshore wind farm, the seawater desalination plant, and the coastal thermal power plant includes: Determine whether the power supply from the offshore wind farm meets the load of the power grid; When the load command of the power grid is less than the real-time power generation of the offshore wind farm, the offshore wind farm supplies power to the power grid according to the commanded power. Determine whether there is any surplus electrical energy in the offshore wind farm; When there is surplus electricity from the offshore wind farm, the surplus electricity is supplied to the seawater desalination unit, and the fresh water produced by the seawater desalination unit is supplied to the boilers of a nearby thermal power plant. When the load command of the power grid exceeds the real-time power generation of the offshore wind farm, the coastal thermal power plant supplements the power grid with electricity. At the same time, the coastal thermal power plant rapidly increases its load to generate electricity, supplementing the power grid's demand on the entire integrated energy system. The offshore wind farm is always operating at full capacity, while the seawater desalination plant and the coastal thermal power plant serve as auxiliary power supply equipment.

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