Coupling energy storage and cogeneration system based on wind energy, solar energy and heat storage

Abstract

The application discloses a coupling energy storage and combined heat and power system based on wind energy, solar energy and heat storage, which comprises an intelligent phase change heat storage unit, wherein the intelligent phase change heat storage unit comprises a phase change heat storage box, a hollow rotating cylinder, a photovoltaic cell and N first phase change heat storage plates, heat exchange water pipes and phase change heat storage materials are arranged in the phase change heat storage box, the hollow rotating cylinder is sleeved on the phase change heat storage box, the hollow rotating cylinder and the phase change heat storage box enclose a closed annular space and are filled with liquid materials, the N first phase change heat storage plates are respectively fixed with evaporation sections of first heat pipes, and the condensation sections of the first heat pipes extend into the annular space; the photovoltaic cell is located above the phase change heat storage box and can move in the vertical direction; the first phase change heat storage plates under the photovoltaic cell can be automatically switched according to the heat storage state of the first phase change heat storage plates and the temperature of the photovoltaic cell, the photovoltaic cell can realize full-weather high-efficiency heat dissipation, and the operation temperature and non-uniformity of the photovoltaic cell are reduced.

Description

Technical Field

[0001] This invention belongs to the field of heating technology, specifically relating to a coupled energy storage and combined heat and power system based on wind energy, solar energy and thermal energy storage. Background Technology

[0002] To achieve dual-carbon goals and reduce dependence on traditional fossil fuels, next-generation cleaner, renewable, and green energy sources such as solar and wind power are the main directions for future energy development. With the depletion of fossil fuels becoming increasingly prominent, photovoltaic and wind power technologies have gradually been recognized and utilized. However, photovoltaic and wind power generation are characterized by intermittency, randomness, and volatility, resulting in poor energy supply stability. Photovoltaic power generation is affected by seasonal, climatic, and diurnal variations; wind power is constrained by wind conditions and wind strength. However, solar and wind energy are highly complementary, exhibiting diurnal and seasonal complementarity. Therefore, integrated wind-solar-storage power supply systems, utilizing both energy sources and combining them with a power storage and charging model, can effectively ensure stable energy supply. Furthermore, by comprehensively considering users' basic energy needs such as electricity, heating, and hot water, combining photovoltaic and wind power, solar thermal generation, and phase change thermal storage technologies can achieve efficient and stable combined heat and power (CHP) supply, improving the overall efficiency of energy utilization.

[0003] Traditional photovoltaic (PV) power generation technology is limited by conversion efficiency and installation area, making it difficult to achieve high power output. Concentrated photovoltaic (CPV) technology, however, uses optical elements such as lenses or mirrors to concentrate sunlight from a large area onto a small area, increasing the radiative energy flux density per unit area of ​​the cell and effectively improving the power generation efficiency of the CPV system. CPV technology can significantly reduce the cost of PV power generation while minimizing the area required for cell installation, solar energy collection, and equipment deployment. However, at high concentration ratios, most of the solar radiation energy is transferred to the solar cells as heat. On the one hand, the portion not converted into electrical energy dissipates as heat, resulting in insufficient utilization and heat loss. On the other hand, it causes a sharp increase in the surface temperature of the photovoltaic cells, reducing the photoelectric conversion efficiency. Furthermore, the cells are easily damaged at high temperatures, leading to rapid aging and a shortened lifespan over time.

[0004] To address the aforementioned issues, contact cooling of photovoltaic cells is typically required to maintain a stable operating temperature and ensure the high power generation efficiency of concentrated photovoltaic (CPV) systems. Currently, conventional cooling methods primarily employ air cooling and water cooling. However, both of these methods require additional power to cool the solar cells, resulting in low efficiency, high energy consumption, and the dissipation of heat generated by the photovoltaic cells, preventing sufficient utilization.

[0005] Adding a phase change energy storage panel (PCS) to the rear of photovoltaic (PV) cells is a common structure in existing photovoltaic (PV) thermal systems. PCS materials utilize latent heat storage, capable of storing a large amount of heat within the phase change temperature range. This high energy density ensures a reasonable temperature range and a compact device size. The PCS absorbs and stores some of the heat emitted by the front PV cells, maintaining the cells at their phase change temperature and achieving cooling and thermal energy utilization. However, in concentrated photovoltaic (CPV) systems, the time the PCS maintains the PV cells at a low temperature is limited. Once the solid PCS material within the panel completely transforms into a liquid, the surface temperature of the PV cells will rise sharply due to the highly concentrated sunlight, necessitating periodic replacement of the PCS. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an intelligent phase change thermal energy storage unit.

[0007] Another objective of this invention is to provide a coupled energy storage and cogeneration system based on wind energy, solar energy, and thermal energy storage, wherein the coupled energy storage and cogeneration system employs the aforementioned intelligent phase change thermal energy storage unit.

[0008] The objective of this invention is achieved through the following technical solution.

[0009] An intelligent phase change thermal energy storage unit includes: a phase change thermal energy storage box, a hollow rotating cylinder, photovoltaic cells, and N first phase change thermal energy storage plates. The phase change thermal energy storage box is a cylindrical body. A heat exchange pipe is installed inside the phase change thermal energy storage box. The space between the heat exchange pipe and the inner wall of the phase change thermal energy storage box is filled with phase change thermal energy storage material. One end of the heat exchange pipe extends out of the phase change thermal energy storage box to form a heat exchange pipe inlet, and the other end of the heat exchange pipe extends out of the phase change thermal energy storage box to form a heat exchange pipe outlet. A groove along the circumferential direction is formed on the outer wall of the right end face of the phase change thermal energy storage box.

[0010] The hollow rotating cylinder is a cavity with one open end. The hollow rotating cylinder is fitted around the right end of the phase change heat storage box. A protrusion is formed at the position opposite to the groove on the hollow rotating cylinder. The protrusion and the groove form a closed annular space. The annular space is filled with liquid material, which is nanofluid or water. N first phase change heat storage plates are arranged along the circumference. Each first phase change heat storage plate is fixed to the evaporation section of a first heat pipe. The condensation section of the first heat pipe passes through the side wall of the hollow rotating cylinder and extends into the annular space.

[0011] The photovoltaic cell is located above the phase change thermal storage box and can move vertically. When the photovoltaic cell is at its lowest point, it is in contact with the first phase change thermal storage plate located at the top.

[0012] The first phase change thermal storage plate includes: two parallel metal plates spaced apart and a phase change thermal storage material encapsulated between the two metal plates.

[0013] The above technical solution also includes: a first motor, the output shaft of which is connected to the hollow rotating cylinder to drive the hollow rotating cylinder to rotate around the axis of the phase change heat storage box.

[0014] In the above technical solution, annular fins are arranged around the periphery of the first heat pipe.

[0015] A coupled energy storage and cogeneration system based on wind energy, solar energy and thermal energy storage includes: an intelligent phase change thermal energy storage unit, a power supply unit and a concentrated photovoltaic power generation and heat collection unit. The power supply unit includes: an inverter and a battery. The inverter is electrically connected to the battery and the photovoltaic cell respectively.

[0016] The concentrated photovoltaic power generation and heat collection unit includes: a Fresnel lens, a solar spectrum frequency divider, and a heat collection plate. The Fresnel lens is located above the photovoltaic cell, the solar spectrum frequency divider is located between the Fresnel lens and the photovoltaic cell, and the heat collection plate is located on one side of the solar spectrum frequency divider. The Fresnel lens converges the light and directs it to the solar spectrum frequency divider. The solar spectrum frequency divider divides the converged light into high-frequency sunlight and low-frequency sunlight. The high-frequency sunlight passes through the solar spectrum frequency divider to reach the photovoltaic cell to generate electrical energy and low-temperature heat energy. The low-frequency sunlight is reflected by the solar spectrum frequency divider to reach the heat collection plate to generate medium- and high-temperature heat energy. The electrical energy generated by the photovoltaic cell is transmitted to the inverter, and the low-temperature heat energy generated by the photovoltaic cell is absorbed by the first phase change thermal storage plate located at the top and in contact with the photovoltaic cell.

[0017] A second phase change heat storage plate is attached to the heat collection plate. One end of the second phase change heat storage plate is fixed to the evaporation section of a second heat pipe. The condensation section of the second heat pipe passes through the side wall of the phase change heat storage box and extends into the phase change heat storage box.

[0018] The second phase change thermal energy storage plate includes: two parallel metal plates spaced apart and a phase change thermal energy storage material encapsulated between the two metal plates.

[0019] The above technical solution also includes: a fan, which is electrically connected to the inverter.

[0020] In the above technical solution, the inverter is electrically connected to the power grid.

[0021] In the above technical solution, the spectral band of high-frequency sunlight is 200-1200nm.

[0022] In the above technical solution, the start-up temperature of the second heat pipe is 115℃, and the phase change temperature range of the phase change heat storage material in the second phase change heat storage plate is 115~118℃.

[0023] In the above technical solution, N=4, and the phase change temperature ranges of the phase change heat storage materials in the N first phase change heat storage plates are 56~59℃, 60~64℃, 65~69℃ and 75~80℃ respectively, and the corresponding start-up temperatures of the first heat pipes are 50℃, 60℃, 65℃ and 75℃ respectively.

[0024] The above technical solution also includes: a first temperature detector and a central controller, wherein the central controller is electrically connected to the first temperature detector, and the first temperature detector is used to detect the temperature of the photovoltaic cell.

[0025] The above technical solution also includes: a second temperature detector, the central controller is electrically connected to the second temperature detector, and the second temperature detector is used to detect the temperature of the first phase change thermal storage plate that is in contact with the photovoltaic cell.

[0026] The above technical solution also includes: a linear motor, which is fixedly mounted on the side of the photovoltaic cell and used to drive the photovoltaic cell to move in a vertical direction; the linear motor is electrically connected to the central controller.

[0027] In the above technical solution, the phase change temperature range of the phase change thermal storage material in the phase change thermal storage box is 42 to 45℃.

[0028] In the above technical solution, foam metal can also be filled between the hot water exchange pipe and the inner wall of the phase change heat storage box.

[0029] The above technical solution also includes: a user water supply and heating unit, which includes: a water source, a first water pump, a first switch valve, a second switch valve, a second water pump, a third switch valve, an electric heater, a third water pump, a user, a domestic hot water storage tank, and a three-way water valve.

[0030] One end of the water supply pipe is connected to the inlet of the heat exchange tube, and the other end of the water supply pipe is connected to the water source. The first water pump and the first switch valve are installed on the water supply pipe.

[0031] The heat exchange tube outlet is connected to the domestic hot water storage tank through a pipe. The three ports of the three-way valve are respectively connected to the domestic hot water storage tank, one end of the first domestic hot water pipe and one end of the second domestic hot water pipe. The other ends of the first domestic hot water pipe and the other ends of the second domestic hot water pipe are both connected to the user. The second switch valve and the second water pump are installed on the first domestic hot water pipe. The third switch valve, the electric heater and the third water pump are installed on the second domestic hot water pipe.

[0032] The domestic hot water storage tank is equipped with a third temperature detector and a water level detection sensor.

[0033] In the above technical solution, the central controller is electrically connected to the first water pump, the first switching valve, the second switching valve, the second water pump, the third switching valve, the electric heater, and the third water pump, respectively.

[0034] The beneficial effects of this invention are as follows:

[0035] (1) The present invention can automatically switch the first phase change energy storage plate under the photovoltaic cell according to the heat storage state of the first phase change energy storage plate and the temperature of the photovoltaic cell, which can realize efficient heat dissipation of the concentrated photovoltaic cell in all climates and reduce the operating temperature and non-uniformity of the photovoltaic cell.

[0036] (2) While generating electricity through solar energy, this invention utilizes phase change energy storage technology to effectively absorb the heat generated by photovoltaic cells and heat collectors under concentrated light conditions, and effectively utilizes the generated heat to meet the user's hot water heating needs.

[0037] (3) This invention utilizes concentrated solar radiation by frequency division. High-frequency sunlight passes through the solar spectrum frequency divider to reach the photovoltaic cell to generate electrical energy and low-temperature heat energy, while low-frequency sunlight is reflected by the solar energy frequency divider to reach the heat collector to generate medium- and high-temperature heat energy, effectively improving the utilization rate of solar energy.

[0038] (4) This invention utilizes the complementarity of wind power generation (wind turbine) and photovoltaic power generation systems to provide stable power for the entire system and better meet the power supply needs of users. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the coupled energy storage and combined heat and power system of the present invention;

[0040] Figure 2 This is a schematic diagram of the structure of an intelligent phase change thermal energy storage unit;

[0041] Figure 3 This is a cross-sectional view of a phase change thermal storage box;

[0042] Figure 4 This is a schematic diagram of the phase change thermal storage box.

[0043] Figure 5 This is a cross-sectional view of an intelligent phase change thermal energy storage unit.

[0044] Among them, 1: photovoltaic cell, 2: solar spectrum divider, 3: Fresnel lens, 4: heat collector, 5: inverter, 6: wind turbine, 7: power grid, 8: battery, 9: connecting frame, 10: linear motor, 11: first phase change thermal storage plate, 12: first temperature detector, 13: second temperature detector, 14: second phase change thermal storage plate, 15: first motor, 16: second heat pipe, 17: hollow rotating cylinder, 18: water source, 19: first water pump, 20: ... 21: First switch valve; 22: Third temperature detector; 23: Second switch valve; 24: Second water pump; 25: Third switch valve; 26: Electric heater; 27: Third water pump; 28: User; 29: Phase change heat storage tank; 30: Hot water replacement pipe; 31: Domestic hot water storage tank; 32: Water level detection sensor; 33: Three-way water valve; 34: Water supply pipe; 35: First domestic hot water pipe; 36: Second domestic hot water pipe; 37: First heat pipe. Detailed Implementation

[0045] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0046] Example 1

[0047] like Figures 2-5 As shown, an intelligent phase change thermal energy storage unit includes: a phase change thermal energy storage box 28, a hollow rotating cylinder 17, a first motor 15, a photovoltaic cell 1, and N first phase change thermal energy storage plates 11. The phase change thermal energy storage box 28 is a cylindrical body. A heat exchange pipe 29 is provided inside the phase change thermal energy storage box 28. The space between the heat exchange pipe 29 and the inner wall of the phase change thermal energy storage box 28 is filled with phase change thermal energy storage material. One end of the heat exchange pipe 29 extends out of the phase change thermal energy storage box 28 to form a heat exchange pipe inlet, and the other end of the heat exchange pipe 29 extends out of the phase change thermal energy storage box 28 to form a heat exchange pipe outlet. A groove along the circumferential direction is formed on the outer wall of the right end face of the phase change thermal energy storage box 28.

[0048] The hollow rotating cylinder 17 is a cavity with one open end. The hollow rotating cylinder 17 is fitted onto the right end of the phase change heat storage box 28. A protrusion is formed on the inner wall of the hollow rotating cylinder 17 at the position opposite to the groove. The protrusion and the groove form a closed annular space. The annular space is filled with liquid material, which is nanofluid or water. N first phase change heat storage plates 11 are arranged in the circumferential direction. Each first phase change heat storage plate 11 is fixed to the evaporation section of a first heat pipe 36. The condensation section of the first heat pipe 36 passes through the side wall of the hollow rotating cylinder 17 and extends into the annular space. The output shaft of the first motor 15 is connected to the hollow rotating cylinder 17 and is used to drive the hollow rotating cylinder 17 to rotate around the axis of the phase change heat storage box 28.

[0049] The phase change energy storage box 28, which comes into contact with the liquid material, is made of a material with high thermal conductivity, such as copper (Cu).

[0050] The photovoltaic cell 1 is located above the phase change heat storage box 28 and can move vertically. When the photovoltaic cell 1 is at its lowest point, the photovoltaic cell 1 is in contact with the first phase change heat storage plate 11 located at the top.

[0051] The first phase change thermal storage plate includes: two parallel metal plates (e.g., aluminum plates) spaced apart, and a phase change thermal storage material encapsulated between the two metal plates.

[0052] The first heat pipe 36 has annular fins arranged around its periphery.

[0053] The working principle of the above-mentioned intelligent phase change thermal energy storage unit is as follows: the phase change thermal energy storage material in the first phase change thermal energy storage plate 11 located at the top and in contact with the photovoltaic cell 1 can absorb heat energy through the photovoltaic cell 1 and transfer the heat energy to the liquid material in the annular space through the first heat pipe 36, and then conduct the heat energy to the phase change thermal energy storage material in the phase change thermal energy storage box 28. The phase change thermal energy storage material in the phase change thermal energy storage box 28 can heat the liquid in the hot water exchange pipe 29 inside the phase change thermal energy storage box 28.

[0054] The first motor 15 rotates, allowing the replacement of the first phase change thermal storage plate 11 that is attached to the photovoltaic cell 1.

[0055] Example 2

[0056] like Figure 1 As shown, a coupled energy storage and cogeneration system based on wind power, solar power and thermal energy storage includes: an intelligent phase change thermal energy storage unit as shown in Example 1, a first temperature detector 12, a second temperature detector 13, a central controller (not shown in the figure), a power supply unit and a concentrated photovoltaic power generation and heat collection unit. The power supply unit includes: an inverter 5 and a battery 8. The inverter 5 is electrically connected to the battery 8 and the photovoltaic cell 1 respectively, and the inverter 5 is electrically connected to the power grid 7.

[0057] The concentrated photovoltaic power generation and heat collection unit includes: a Fresnel lens 3, a solar spectrum frequency divider 2, and a heat collection plate 4. The Fresnel lens 3 is located above the photovoltaic cell 1. The solar spectrum frequency divider 2 is located between the Fresnel lens 3 and the photovoltaic cell 1. The heat collection plate 4 is located on one side of the solar spectrum frequency divider 2. The Fresnel lens 3 converges the light and directs it to the solar spectrum frequency divider 2. The solar spectrum frequency divider 2 divides the converged light into high-frequency sunlight with a spectral band of 200-1200nm and low-frequency sunlight with the remaining spectral band. The high-frequency sunlight passes through the solar spectrum frequency divider 2 to reach the photovoltaic cell 1 to generate electrical energy and low-temperature heat energy. The low-frequency sunlight is reflected by the solar spectrum frequency divider 2 to reach the heat collection plate 4 to generate medium- and high-temperature heat energy. The electrical energy generated by the photovoltaic cell 1 is transmitted to the inverter 5. The low-temperature heat energy generated by the photovoltaic cell 1 is absorbed by the first phase change heat storage plate 11 located at the top and in contact with the photovoltaic cell 1, realizing the efficient utilization of solar energy through frequency division. The Fresnel lens 3 is made of polyolefin or glass; the focusing ratio of the Fresnel lens 3 is 2-18 times.

[0058] A second phase change heat storage plate 14 is attached to the heat collector plate 4. One end of the second phase change heat storage plate 14 is fixed to the evaporation section of a second heat pipe 16. The condensation section of the second heat pipe 16 passes through the side wall of the phase change heat storage box 28 and extends into the phase change heat storage box 28. The second phase change heat storage plate includes two parallel metal plates spaced apart and a phase change heat storage material encapsulated between the two metal plates. The start-up temperature of the second heat pipe 16 is 115°C, and the phase change temperature range of the phase change heat storage material in the second phase change heat storage plate 14 is 115–118°C (the phase change heat storage material is, for example, MgCl2·6H2O). The second phase change heat storage plate and the second heat pipe can conduct the medium-to-high temperature heat energy generated by the heat collector plate to the phase change heat storage box 28.

[0059] N=4, and the starting temperatures of the first heat pipes 36 corresponding to the N first phase change heat storage plates 11 arranged along the circumference are 50℃, 60℃, 65℃, and 75℃, respectively. The phase change temperature ranges of the phase change heat storage materials in the first phase change heat storage plates 11 corresponding to the first heat pipes 36 are 56~59℃ (phase change heat storage materials such as myristic acid), 60~64℃ (phase change heat storage materials such as paraffin), 65~69℃ (phase change heat storage materials such as stearic acid), and 75~80℃ (phase change heat storage materials such as Ba(OH)2·8H2O), respectively. When the temperature of the phase change heat storage material in the first phase change heat storage plate is higher than the starting temperature of the first heat pipe, the first heat pipe starts to conduct heat.

[0060] The central controller is electrically connected to the first temperature detector 12, the second temperature detector 13 and the first motor 15 respectively; the first temperature detector 12 is used to detect the temperature of the photovoltaic cell 1, and the second temperature detector 13 is used to detect the temperature of the first phase change heat storage plate 11 that is in contact with the photovoltaic cell 1.

[0061] By detecting the temperature of the photovoltaic cell 1 using the first temperature detector 12, selecting the first phase change heat storage plate 11 whose temperature falls within the phase change temperature range of the phase change heat storage material, and placing the first phase change heat storage plate 11 in contact with the photovoltaic cell 1, efficient heat dissipation of the photovoltaic cell can be achieved in all weather conditions.

[0062] The linear motor 10 is fixedly mounted to the side of the photovoltaic cell 1 and is used to drive the photovoltaic cell 1 to move in the vertical direction. The slider of the linear motor 10 is fixedly mounted to the side of the photovoltaic cell 1 through the connecting frame 9. The linear motor 10 is electrically connected to the central controller.

[0063] When the first temperature detection device 12 detects that the temperature of the photovoltaic cell 1 exceeds the maximum value of the phase change temperature range of the phase change heat storage material in the first phase change heat storage plate 11 that is in contact with it, or when the second temperature detection device 13 detects that the temperature of the first phase change heat storage plate 11 exceeds the maximum value of the phase change temperature range of the phase change heat storage material in the first phase change heat storage plate 11, the central controller automatically controls the linear motor 10 to start and drive the photovoltaic cell 1 to rise to a set height; then, the central controller automatically controls the first motor 15 to start and drive the hollow rotating cylinder 17 to rotate, so that the first phase change heat storage plate 11, which is within the phase change temperature range of the phase change heat storage material where the temperature of the photovoltaic cell 1 is at this time, is rotated to below the photovoltaic cell 1; finally, the central controller automatically controls the linear motor 10 to start and drive the photovoltaic cell 1 to fall to a set height, so that the photovoltaic cell 1 and the first phase change heat storage plate 11 are tightly attached together. The first phase change heat storage plate 11 absorbs heat from the photovoltaic cell 1 through direct contact. When the temperature of the phase change heat storage material inside the first phase change heat storage plate 11 is higher than the start-up temperature of the first heat pipe 36, the first heat pipe 36 starts working, transferring the heat from the first phase change heat storage plate 11 to the liquid material filling the annular space and the phase change heat storage box 28. The phase change heat storage material inside the phase change heat storage box 28 stores the heat. Water in the hot water exchange pipe 29 flows through the phase change heat storage box, and the water exchanges heat with the phase change heat storage material (or "phase change heat storage material and foamed metal") inside the phase change heat storage box 28. The heat is carried out of the phase change heat storage box 28 with the water flow.

[0064] A thermally conductive silicone grease with a high thermal conductivity is placed below the photovoltaic cell 1.

[0065] It also includes: wind turbine 6, which is electrically connected to inverter 5. Under sunlight conditions, photovoltaic cells convert solar energy into electrical energy when exposed to sunlight, and under wind conditions, the wind turbine converts wind energy into electrical energy. The electrical energy is stored in batteries or used to power coupled energy storage and combined heat and power systems and the power grid.

[0066] Example 3

[0067] Based on Embodiment 2, the system further includes a user water supply and heating unit, comprising: a water source 18, a first water pump 19, a first switch valve 20, a second switch valve 22, a second water pump 23, a third switch valve 24, an electric heater 25, a third water pump 26, a user 27, a domestic hot water storage tank 30, and a three-way water valve 32. The phase change heat storage material in the phase change heat storage tank has a phase change temperature range of 42-45℃, such as lauric acid, which can well meet the user's water supply and heating temperature requirements. In addition to the phase change heat storage material, foam metal can also be filled between the inner wall of the hot water exchange pipe 29 and the phase change heat storage tank 28, such as foam copper with a pore size of 2-3mm and a porosity of 95%. One end of the water supply pipe 33 is connected to the inlet of the heat exchange pipe, and the other end of the water supply pipe 33 is connected to the water source 18. The first water pump 19 and the first switch valve 20 are installed on the water supply pipe 33.

[0068] The outlet of the heat exchange tube is connected to the domestic hot water storage tank 30 through a pipe. The three ports of the three-way water valve 32 are respectively connected to the domestic hot water storage tank 30, one end of the first domestic hot water pipe 34 and one end of the second domestic hot water pipe 35. The other end of the first domestic hot water pipe 34 and the other end of the second domestic hot water pipe 35 are both connected to the user 27. The second switch valve 22 and the second water pump 23 are installed on the first domestic hot water pipe 34. The third switch valve 24, the electric heater 25 and the third water pump 26 are installed on the second domestic hot water pipe 35.

[0069] The domestic hot water storage tank 30 is equipped with a third temperature detector 21 and a water level detection sensor 31.

[0070] The central controller is electrically connected to the first water pump 19, the first switching valve 20, the second switching valve 22, the second water pump 23, the third switching valve 24, the electric heater 25, and the third water pump 26.

[0071] When the water level sensor 31 detects that there is not enough hot water in the domestic hot water storage tank 30, the central controller automatically controls the first water pump 19 and the first switch valve 20 to open, and the water source and the heat exchange pipe inlet are connected to form a loop. Cold water enters the hot water exchange pipe 29 through the water supply pipe 33 and exchanges heat with the phase change heat storage material (or "foam metal and phase change heat storage material") in the phase change heat storage tank 28. The heated hot water is transported to the domestic hot water storage tank 30 through the pipe.

[0072] For example, if the temperature of the hot water in the domestic hot water storage tank 30 is detected by the third temperature detector 21, and its temperature is lower than the set temperature, the central controller will automatically control the third water pump 26 and the third switch valve 24 to open, and the second switch valve 22 to close, thus connecting the domestic hot water storage tank 30, the electric heater 25, and the user to form a circuit. The electric heater 25 will then reheat the hot water that does not meet the set temperature, and connect it to the user through the second domestic hot water pipe 35 for the user's use.

[0073] If the temperature of the hot water in the domestic hot water storage tank 30 is detected by the third temperature detector 21, and the temperature is not lower than the set temperature, the central controller will automatically control the second water pump 23 and the second switch valve 22 to open and the third switch valve 24 to close, so that the domestic hot water storage tank 30 and the user are connected to form a loop, and the hot water is connected to the user through the first domestic hot water pipe 34 for the user to use.

[0074] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. An intelligent phase change thermal energy storage unit, characterized in that, include: The system comprises a phase change thermal storage box (28), a hollow rotating cylinder (17), a photovoltaic cell (1), and N first phase change thermal storage plates (11). The phase change thermal storage box (28) is a cylindrical body. A heat exchange pipe (29) is installed inside the phase change thermal storage box (28). The space between the heat exchange pipe (29) and the inner wall of the phase change thermal storage box (28) is filled with phase change thermal storage material. One end of the heat exchange pipe (29) extends out of the phase change thermal storage box (28) to form a heat exchange pipe inlet, and the other end of the heat exchange pipe (29) extends out of the phase change thermal storage box (28) to form a heat exchange pipe outlet. A groove along the circumferential direction is formed on the outer wall of the right end face of the phase change thermal storage box (28). The hollow rotating cylinder (17) is a cavity with one end open. The hollow rotating cylinder (17) is fitted onto the right end of the phase change heat storage box (28). A protrusion is formed at the position opposite to the groove of the hollow rotating cylinder (17). The protrusion and the groove form a closed annular space. The annular space is filled with liquid material, which is nanofluid or water. N first phase change heat storage plates (11) are arranged along the circumference. Each first phase change heat storage plate (11) is fixed to the evaporation section of a first heat pipe (36). The condensation section of the first heat pipe (36) passes through the side wall of the hollow rotating cylinder (17) and extends into the annular space. The photovoltaic cell (1) is located above the phase change heat storage box (28) and can move vertically. When the photovoltaic cell (1) is at its lowest point, the photovoltaic cell (1) is in contact with the first phase change heat storage plate (11) located at the top. The first phase change heat storage plate (11) includes: two parallel metal plates spaced apart and a phase change heat storage material encapsulated between the two metal plates.

2. The intelligent phase change thermal energy storage unit according to claim 1, characterized in that, Also includes: The first motor (15) has its output shaft connected to the hollow rotating cylinder (17) to drive the hollow rotating cylinder (17) to rotate around the axis of the phase change heat storage box (28).

3. A coupled energy storage and combined heat and power system based on wind energy, solar energy, and thermal energy storage, characterized in that, include: The intelligent phase change thermal storage unit, power supply unit and concentrated photovoltaic power generation and heat collection unit according to any one of claims 1 to 2, wherein the power supply unit includes: an inverter (5) and a storage battery (8), wherein the inverter (5) is electrically connected to the storage battery (8) and the photovoltaic cell (1) respectively; The concentrated photovoltaic power generation and heat collection unit includes: Fresnel lens (3), solar spectrum frequency divider (2) and heat collection plate (4). The Fresnel lens (3) is located above the photovoltaic cell (1). The solar spectrum frequency divider (2) is set between the Fresnel lens (3) and the photovoltaic cell (1). The heat collection plate (4) is located on one side of the solar spectrum frequency divider (2). The Fresnel lens (3) converges the light and incident it onto the solar spectrum frequency divider (2). The solar spectrum frequency divider (2) divides the converged light into high-frequency sunlight and low-frequency sunlight. The high-frequency sunlight passes through the solar spectrum frequency divider (2) to reach the photovoltaic cell (1) to generate electrical energy and low-temperature heat energy. The low-frequency sunlight is reflected by the solar spectrum frequency divider (2) to reach the heat collection plate (4) to generate medium- and high-temperature heat energy. The electrical energy generated by the photovoltaic cell (1) is transmitted to the inverter (5). The low-temperature heat energy generated by the photovoltaic cell (1) is absorbed by the first phase change heat storage plate (11) located at the top and in contact with the photovoltaic cell (1). A second phase change heat storage plate (14) is attached to the heat collection plate (4). One end of the second phase change heat storage plate (14) is fixed to the evaporation section of a second heat pipe (16). The condensation section of the second heat pipe (16) passes through the side wall of the phase change heat storage box (28) and extends into the phase change heat storage box (28). The second phase change heat storage plate (14) includes: two parallel metal plates spaced apart and a phase change heat storage material encapsulated between the two metal plates.

4. The coupled energy storage and combined heat and power system according to claim 3, characterized in that, It also includes: a fan (6), which is electrically connected to an inverter (5), and the inverter (5) is electrically connected to a power grid (7). The phase change temperature range of the phase change heat storage material in the phase change heat storage box (28) is 42 to 45°C.

5. The coupled energy storage and combined heat and power system according to claim 3, characterized in that, The spectral band of high-frequency sunlight is 200-1200nm.

6. The coupled energy storage and combined heat and power system according to claim 3, characterized in that, The start-up temperature of the second heat pipe (16) is 115°C, and the phase change temperature range of the phase change heat storage material in the second phase change heat storage plate (14) is 115 to 118°C.

7. The coupled energy storage and combined heat and power system according to claim 3, characterized in that, N=4, the phase change temperature ranges of the phase change heat storage materials in the N first phase change heat storage plates (11) are 56~59℃, 60~64℃, 65~69℃ and 75~80℃ respectively, and the corresponding start-up temperatures of the first heat pipes (36) are 50℃, 60℃, 65℃ and 75℃ respectively.

8. The coupled energy storage and combined heat and power system according to claim 3, characterized in that, Also includes: The first temperature detector (12) and the central controller are electrically connected to the first temperature detector (12), which is used to detect the temperature of the photovoltaic cell (1).

9. The coupled energy storage and combined heat and power system according to claim 8, characterized in that, Also includes: The user water supply and heating unit includes: a water source (18), a first water pump (19), a first switch valve (20), a second switch valve (22), a second water pump (23), a third switch valve (24), an electric heater (25), a third water pump (26), a user (27), a domestic hot water storage tank (30), and a three-way water valve (32); One end of the water supply pipe (33) is connected to the heat exchange pipe inlet, and the other end of the water supply pipe (33) is connected to the water source (18). The first water pump (19) and the first switch valve (20) are installed on the water supply pipe (33). The outlet of the heat exchange tube is connected to the domestic hot water storage tank (30) through a pipe. The three ports of the three-way water valve (32) are connected to the domestic hot water storage tank (30), one end of the first domestic hot water pipe (34), and one end of the second domestic hot water pipe (35), respectively. The other end of the first domestic hot water pipe (34) and the other end of the second domestic hot water pipe (35) are connected to the user (27). The second switch valve (22) and the second water pump (23) are installed on the first domestic hot water pipe (34). The third switch valve (24), the electric heater (25), and the third water pump (26) are installed on the second domestic hot water pipe (35). A third temperature detector (21) and a water level sensor (31) are installed inside the domestic hot water storage tank (30).

10. The coupled energy storage and combined heat and power system according to claim 9, characterized in that, The central controller is electrically connected to the first water pump (19), the first switching valve (20), the second switching valve (22), the second water pump (23), the third switching valve (24), the electric heater (25), and the third water pump (26).

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