A cross-day-night-seasonal energy storage system coupled with physical-chemical heat storage
A hybrid solar energy storage system using phase change and thermochemical methods stabilizes energy output across day and night and seasons, addressing intermittency and seasonality issues in solar energy systems.
Patent Information
- Application Number
- CN202210860263.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-07-21
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2042-07-21
AI Technical Summary
The existing solar energy storage systems have problems such as large heat loss or insufficient flexibility over a long span, which cannot meet the adjustment needs of medium and large capacity, long-term and cross-season energy supply throughout the year.
The system coupling design of physical energy storage and thermochemical energy storage is adopted. Through solar concentrated photothermal mirror field, phase change physical energy storage unit, thermochemical energy storage unit and related valve pipelines, energy storage regulation of day and night span and seasonal span is achieved, and combined with the gas-solid phase thermochemical heat storage system to strengthen heat transfer and reaction process.
It has achieved stable output of solar energy throughout the day and throughout the year, reduced fluctuations in energy output throughout the year, improved the flexibility and efficiency of energy storage, and met the peak-shaving needs of solar energy throughout the year.
Smart Images
Figure CN115235130B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of solar thermal utilization, and specifically relates to a cross-day-night-season energy storage system with physical-chemical heat storage coupling. Background Art
[0002] Solar energy has the advantages of wide acquisition sources, being green, clean, and renewable, and is an ideal clean and renewable energy that can replace fossil fuels. However, the distribution of solar energy has intermittent and unstable fluctuations in time, specifically manifested as: more in summer and less in winter, available during the day but not at night, and is extremely vulnerable to local real-time weather conditions, making it difficult to continuously and stably supply energy. This further limits the utilization space of solar energy in traditional systems such as power generation and grid connection and central heating. To this end, a better solution is to adopt mature energy storage technologies, store excess solar energy in specific media, and release it when the energy is insufficient to achieve the peak shaving function. For existing energy storage systems, due to the use of only a single energy storage method, only using physical energy storage has a large heat loss during long-term energy storage, and only using chemical energy storage has complex reactions and insufficient flexibility under short-term conditions, and cannot meet the requirements of large-capacity, long-term, and cross-seasonal regulation in the annual solar energy supply.
[0003] In the research of the field of energy storage science, physical energy storage, such as phase change energy storage, is usually applicable to energy storage occasions with short time spans, such as the cross-day-night scale; while thermochemical energy storage, which uses reversible endothermic and exothermic reactions to store thermal energy, has significant advantages such as high energy storage density, stable storage media, high reaction temperature, and small long-term heat storage loss, and can effectively solve the conversion, storage, and regeneration of energy under long time spans, such as the cross-season scale.
[0004] To achieve the efficient and stable output of solar energy throughout the year, system design is required to couple physical energy storage methods with short time spans and chemical energy storage methods with long time spans, so as to achieve cross-day-night-season regulation of solar energy, greatly improve the fluctuation problem of annual solar energy output, and achieve peak shaving and stable output of solar energy throughout the day and year, opening up a good solution for the efficient and stable utilization of solar energy and grid connection and other requirements. Currently, the research on this cross-day-night-season energy storage system with physical-chemical heat storage coupling is in its infancy. Summary of the Invention
[0005] In order to overcome the above technical problems, the purpose of the present invention is to provide a cross-day-night-season energy storage system with physical-chemical heat storage coupling, which realizes energy storage regulation for both day-night and season spans through the system coupling design of physical energy storage and thermochemical energy storage, greatly reducing the fluctuation of annual solar energy output and achieving peak shaving and stable output of solar energy throughout the day and year.
[0006] To achieve the above purpose, the technical solution adopted by the present invention is:
[0007] A cross-day-night and cross-season energy storage system coupling physical-chemical heat storage, comprising a solar concentrating solar thermal mirror field 1, a phase change physical energy storage unit 2, a thermochemical energy storage unit 3, an output terminal 4 and related valves and pipelines;
[0008] The solar concentrating solar thermal mirror field 1 is used to convert solar energy into heat energy and transport it to the output terminal 4 through a heat transfer fluid to complete the supply;
[0009] The phase change physical energy storage unit 2 is used to store the excess heat energy of the solar concentrating solar thermal mirror field 1. The phase change physical energy storage unit 2 includes a heat exchanger 5 and a phase change energy storage material tank 6, and stores it in the phase change energy storage material tank 6 through the heat exchanger 5; when the heat energy of the solar concentrating solar thermal mirror field 1 is insufficient, the stored heat energy is transported to the output terminal 4 through the heat transfer fluid of the heat exchanger 5 to complete the supply;
[0010] The thermochemical energy storage unit 3 is used to store the excess heat energy of the solar concentrating solar thermal mirror field 1 as chemical energy through an endothermic reaction in a gas-solid phase thermochemical heat storage system 7 and achieve long-term stable storage of energy; when the heat energy is insufficient, the phase change physical energy storage unit 2 is transported to a steam generator 8 through a heat transfer fluid, and the heat energy is transported to the output terminal 4 to complete the supply.
[0011] In the summer day condition, the solar energy is excessive. While normal supply is required, energy storage for night and winter is also needed. The solar concentrating solar thermal mirror field 1 converts solar energy into heat energy and transports it to the output terminal 4 through a heat transfer fluid to complete the supply; at the same time, a part of the excessive heat energy during the day is transported to the phase change physical energy storage unit 2 and stored in the phase change energy storage material tank 6 through the heat exchanger 5; another part of the excessive heat energy is transported to the thermochemical energy storage unit 3, and is stored as chemical energy through an endothermic reaction in the gas-solid phase thermochemical heat storage system 7 to achieve long-term stable storage of energy, so as to realize the functions of cross-day-night storage and cross-season storage of solar energy.
[0012] In the summer night condition, there is no solar energy input. It is necessary to output and supply the energy stored in the physical energy storage unit during the day. The phase change physical energy storage unit 2 outputs the heat energy stored in the phase change energy storage material tank 6 through the heat exchanger 5 and transports it to the output terminal 4 through a heat transfer fluid to complete the supply, so as to realize the function of cross-day-night peak shaving supply of solar energy.
[0013] Under the winter daytime condition, the solar energy is insufficient. All the solar energy needs to be used to provide the water vapor required for the reaction for the chemical energy storage unit, and the energy stored in the chemical energy storage unit in summer is output and supplied. The solar concentrating solar thermal mirror field 1 converts solar energy into heat energy, and transports it to the water vapor generator 8 through the heat transfer fluid, providing the reaction gas required for the exothermic reaction of the gas-solid phase thermochemical energy storage system 7, and converting chemical energy into heat energy through the thermochemical reaction in the gas-solid phase thermochemical energy storage system 7, and transporting it to the output terminal 4 to complete the supply; at the same time, a part of the excess heat energy during the day is transported to the phase change physical energy storage unit 2, and stored in the phase change energy storage material box 6 through the heat exchanger 5 to achieve the function of solar energy cross-seasonal peak shaving supply.
[0014] Under the winter night condition, there is no solar energy input. The energy stored in the chemical energy storage unit in summer needs to be output and supplied. The phase change physical energy storage unit 2 outputs the heat energy stored in the phase change energy storage material box 6 through the heat exchanger 5, and transports it to the water vapor generator 8 through the heat transfer fluid, providing the reaction gas required for the exothermic reaction of the gas-solid phase thermochemical energy storage system 7, and converting chemical energy into heat energy through the thermochemical reaction in the gas-solid phase thermochemical energy storage system 7, and transporting it to the output terminal 4 to complete the supply, so as to achieve the function of solar energy cross-seasonal peak shaving supply.
[0015] The gas-solid phase thermochemical energy storage system 7 used by the water vapor generator 8 has an internally indirect heat transfer coil structure 10 and a heat transfer enhanced fin structure 11 to achieve rapid and efficient energy storage in the reaction bed. A reaction gas inlet mesh channel structure 12 is arranged in the central part of the reaction gas to make the reaction gas evenly distributed and react well inside the reaction bed, thereby improving the energy storage rate of the reaction bed and realizing the function of rapid heat absorption and release of the thermochemical energy storage unit 3.
[0016] Advantages of the present invention:
[0017] 1. A physical-chemical energy storage coupled cross-day-night-season energy storage system provided by the present invention can realize energy storage regulation with a day-night span through physical energy storage, and at the same time realize energy storage regulation with a season span through thermochemical energy storage, greatly improving the fluctuation problem of the annual solar energy output, realizing the stable output of solar energy throughout the day and the whole year, and opening up a good solution for the efficient and stable utilization of solar energy and the needs of grid connection, etc.
[0018] 2. A gas-solid phase thermochemical energy storage system provided by the present invention can strengthen the heat transfer process and reaction diffusion process in the gas-solid phase thermochemical energy storage reaction through the innovative design of the internal coil structure, fin structure and reaction gas inlet mesh channel structure, thereby improving the energy storage rate and efficiency of the reaction bed, realizing the efficient and rapid storage and release of heat energy, and realizing a good heat energy regeneration effect. Description of the Drawings
[0019] Figure 1 It is a schematic flow diagram of a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention.
[0020] Figure 2 It is a schematic diagram of the operation mode of a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention during the day in summer.
[0021] Figure 3 It is a schematic diagram of the operation mode of a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention at night in summer.
[0022] Figure 4 It is a schematic diagram of the operation mode of a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention during the day in winter.
[0023] Figure 5 It is a schematic diagram of the operation mode of a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention at night in winter.
[0024] Figure 6 It is a specific structural schematic diagram of the gas-solid phase thermochemical heat storage system used in a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention.
[0025] Figure 7 It is a schematic diagram of the effect of cross-season regulation of a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention (taking a northern city as an example).
[0026] Figure 8 It is a schematic diagram of the effect of cross-day-night regulation of a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention (taking a northern city as an example).
[0027] The corresponding marks of each part in the figure are: solar concentrating solar thermal mirror field 1, phase change physical energy storage unit 2, thermochemical energy storage unit 3, output terminal 4, heat exchanger 5, phase change energy storage material box 6, gas-solid phase thermochemical heat storage system 7, steam generator 8, reaction gas supply water tank 9, coil structure 10, fin structure 11, reaction gas inlet mesh channel structure 12. Detailed implementation manners
[0028] The present invention will be further described in detail below with reference to the embodiments.
[0029] As Figure 1 shown, Figure 1Schematic flow diagram of a physical-chemical coupled heat storage cross-day-night-season energy storage system provided by the present invention. The corresponding labels for each part in the figure are: solar concentrating solar thermal mirror field 1, phase change physical energy storage unit 2, thermochemical energy storage unit 3, output terminal 4, heat exchanger 5, phase change energy storage material tank 6, gas-solid phase thermochemical heat storage system 7, steam generator 8, and reaction gas supply water tank 9.
[0030] As Figure 2 shown, Figure 2 Schematic diagram of the operation mode of a physical-chemical coupled heat storage cross-day-night-season energy storage system provided by the present invention under the summer daytime condition. Under the summer daytime condition, the solar concentrating solar thermal mirror field 1 converts solar energy into heat energy and transports it to the output terminal 4 through the heat transfer fluid to complete the supply; at the same time, a part of the excess heat energy during the day is transported to the phase change physical energy storage unit 2, and is stored in the phase change energy storage material tank 6 through the heat exchanger 5; another part of the excess heat energy is transported to the thermochemical energy storage unit 3, and an endothermic reaction is carried out through the gas-solid phase thermochemical heat storage system 7 to store it as chemical energy and achieve long-term stable storage of energy, so as to realize the functions of cross-day-night storage and cross-season storage of solar energy.
[0031] As Figure 3 shown, the figure is a schematic diagram of the operation mode of a physical-chemical coupled heat storage cross-day-night-season energy storage system provided by the present invention under the summer night condition. Under the summer night condition, the phase change physical energy storage unit 2 outputs the heat energy stored in the phase change energy storage material tank 6 through the heat exchanger 5, and transports it to the output terminal 4 through the heat transfer fluid to complete the supply, so as to realize the function of cross-day-night peak shaving supply of solar energy.
[0032] As Figure 4 shown, Figure 4 Schematic diagram of the operation mode of a physical-chemical coupled heat storage cross-day-night-season energy storage system provided by the present invention under the winter daytime condition. Under the winter daytime condition, the solar concentrating solar thermal mirror field 1 converts solar energy into heat energy and transports it to the steam generator 8 through the heat transfer fluid to provide the required reaction gas for the exothermic reaction of the gas-solid phase thermochemical heat storage system 7, and converts chemical energy into heat energy through a thermochemical reaction in the gas-solid phase thermochemical heat storage system 7 and transports it to the output terminal 4 to complete the supply; at the same time, a part of the excess heat energy during the day is transported to the phase change physical energy storage unit 2, and is stored in the phase change energy storage material tank 6 through the heat exchanger 5, so as to realize the function of cross-season peak shaving supply of solar energy.
[0033] As Figure 5 shown, Figure 5Schematic diagram of the operation mode of a physical-chemical coupled heat storage across day-night and season energy storage system provided by the present invention under the winter night condition. Under the winter night condition, the phase change physical energy storage unit 2 outputs the thermal energy stored in the phase change energy storage material tank 6 through the heat exchanger 5, and transports it to the steam generator 8 through the heat transfer fluid, providing the reaction gas required for the exothermic reaction of the gas-solid phase thermochemical energy storage system 7, and converting chemical energy into thermal energy through a thermochemical reaction within the gas-solid phase thermochemical energy storage system 7, and transporting it to the output terminal 4 to complete the supply, so as to realize the function of solar energy cross-season peak shaving supply.
[0034] As Figure 6 shown, Figure 6 Schematic diagram of the specific structure of the gas-solid phase thermochemical energy storage system used in a physical-chemical coupled heat storage across day-night and season energy storage system provided by the present invention. The corresponding marks of each part in the figure are: coil structure 10, fin structure 11, reaction gas inlet mesh channel structure 12. The coil structure 10 and the fin structure 11 are used to strengthen the heat transfer process inside the reaction bed and realize rapid and efficient energy storage of the reaction bed. The reaction gas inlet mesh channel structure arranged in the central part of the reaction gas enables the reaction gas to be evenly distributed inside the reaction bed and then react well, thereby improving the energy storage rate of the reaction bed and realizing the function of rapid heat absorption and release of the thermochemical energy storage unit 3.
[0035] Next, taking the energy demand and solar energy resource distribution of a certain city as an example, and taking paraffin phase change physical energy storage material and Ca(OH)2 / CaO thermochemical energy storage system as examples, the outstanding application advantages of the present invention will be described.
[0036] As Figure 7 and Figure 8 shown, Figure 7 and Figure 8 The solid lines in the figures are respectively the schematic diagram of the annual solar radiation distribution with seasons and the schematic diagram of the all-day solar radiation distribution with day and night in this city. Specifically, it shows that there is more in summer and less in winter, there is solar radiation during the day but none at night, and it is extremely vulnerable to the daily real-time weather conditions of the local area, with a very large fluctuation range. The variance of the daily solar energy received in this city is as high as 84071, and the fluctuation range reaches 800 W / ㎡. The variance of the annual solar energy received is as high as 57896, making it difficult to supply energy continuously and stably. Therefore, a physical-chemical coupled heat storage across day-night and season energy storage system provided by the present invention is equipped for a certain city, so as to realize the stable and continuous supply of energy as shown by the dotted lines in Figure 7 and Figure 8 the figures.
[0037] Paraffin phase change physical energy storage materials are adopted, with a temperature range of about 100 °C, which is used to adjust the energy fluctuation during the day-night span; a Ca(OH)2 / CaO thermochemical energy storage system is adopted, with a temperature range of 300 - 550 °C, which is used to adjust the energy fluctuation during the season span. The temperature can be directionally controlled by adjusting the steam partial pressure inside the gas-solid phase thermochemical reaction bed to meet the actual output end matching requirements.
[0038] Taking the total annual solar energy received in a certain city as 3.91×10 9 J / m 2 and the winter heating demand as 1.309×10 13 J as an example, referring to a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention, if it is required to supply the winter heating of this city completely by the solar energy received throughout the year, then an effective area of the solar thermal mirror field of 3.35×10 6 m 2 should be equipped, and a total of 1.3×10 11 tons of the thermochemical energy storage material Ca(OH)2. This result shows that a physical-chemical heat storage coupled cross-day-night-season energy storage system provided by the present invention is completely feasible in practical applications.
[0039] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A cross-day-night-season energy storage system coupling physical-chemical heat storage, characterized in that, It includes a solar concentrating solar thermal mirror field (1), a phase change physical energy storage unit (2), a thermochemical energy storage unit (3), an output terminal (4), and related valves and pipelines; The solar concentrating solar thermal mirror field (1) is used to convert solar energy into heat energy and deliver it to the output terminal (4) through a heat transfer fluid to complete the supply; The phase change physical energy storage unit (2) is used to store the excess heat energy of the solar concentrating solar thermal mirror field (1). The phase change physical energy storage unit (2) includes a heat exchanger (5) and a phase change energy storage material box (6), and stores it in the phase change energy storage material box (6) through the heat exchanger (5); when the heat energy of the solar concentrating solar thermal mirror field (1) is insufficient, the stored heat energy is delivered to the output terminal (4) through the heat transfer fluid of the heat exchanger (5) to complete the supply; The thermochemical energy storage unit (3) is used to store the excess heat energy of the solar concentrating solar thermal mirror field (1). Through a gas-solid phase thermochemical heat storage system (7), it undergoes an endothermic reaction to store it as chemical energy and achieve long-term stable storage of energy; when the heat energy is insufficient, the phase change physical energy storage unit (2) delivers it to a steam generator (8) through a heat transfer fluid, and delivers the heat energy to the output terminal (4) to complete the supply; Under the summer daytime working condition, the solar concentrating solar thermal mirror field (1) converts solar energy into heat energy and delivers it to the output terminal (4) through a heat transfer fluid to complete the supply; at the same time, a part of the excess heat energy during the day is delivered to the phase change physical energy storage unit (2) and stored in the phase change energy storage material box (6) through the heat exchanger (5); another part of the excess heat energy is delivered to the thermochemical energy storage unit (3), and through the gas-solid phase thermochemical heat storage system (7), it undergoes an endothermic reaction to store it as chemical energy and achieve long-term stable storage of energy, so as to realize the functions of cross-day and cross-season storage of solar energy; Under the summer night working condition, the phase change physical energy storage unit (2) outputs the heat energy stored in the phase change energy storage material box (6) through the heat exchanger (5) and delivers it to the output terminal (4) through a heat transfer fluid to complete the supply, so as to realize the function of cross-day peak shaving supply of solar energy; Under the winter daytime working condition, the solar concentrating solar thermal mirror field (1) converts solar energy into heat energy and delivers it to the steam generator (8) through a heat transfer fluid to provide the reaction gas required for the exothermic reaction of the gas-solid phase thermochemical heat storage system (7), and through a thermochemical reaction in the gas-solid phase thermochemical heat storage system (7), converts the chemical energy into heat energy and delivers it to the output terminal (4) to complete the supply; at the same time, a part of the excess heat energy during the day is delivered to the phase change physical energy storage unit (2) and stored in the phase change energy storage material box (6) through the heat exchanger (5), so as to realize the function of cross-season peak shaving supply of solar energy; Under the winter night working condition, the phase change physical energy storage unit (2) outputs the thermal energy stored in the phase change energy storage material box (6) through the heat exchanger (5), and transports it to the steam generator (8) through the heat transfer fluid, providing the reaction gas required for the exothermic reaction of the gas-solid phase thermochemical energy storage system (7), and converting the chemical energy into thermal energy through the thermochemical reaction within the gas-solid phase thermochemical energy storage system (7), and transporting it to the output terminal (4) to complete the supply, so as to realize the function of solar seasonal peak shaving supply.
2. A physical-chemical coupled heat storage across day-night and season energy storage system according to claim 1, characterized in that, The gas-solid phase thermochemical energy storage system (7) used in the steam generator (8) has an internally indirect heat transfer coil structure (10) and a fin structure (11) for enhanced heat transfer inside to achieve rapid and efficient energy storage in the reaction bed, and a reaction gas inlet mesh channel structure (12) is provided in the central part of the reaction gas.
Citation Information
Patent Citations
Seasonal mixed heat storage cold and hot combined supply system
CN110195991A