A solar thermal storage system and method based on quantum dot spectrum modulation

Abstract

A solar thermal storage system and method based on quantum dot spectrum modulation, the system is composed of a special working fluid and pipeline, a working fluid spray evaporation section, a molten salt heat exchange section and a working fluid return section; the special working fluid and pipeline include working fluid, a small diameter pipeline and a T-shaped pipeline; the working fluid is a mixture of water and millimeter particles, the millimeter particles are composed of a substrate and a quantum dot thin layer wrapped around the substrate, and the working fluid has an absorption spectrum that matches the solar spectrum; the working fluid spray evaporation section includes a first solar concentrator, a nozzle and a second solar concentrator; the molten salt heat exchange section includes a molten salt tank, a molten salt pump and a molten salt circulation pipeline; the working fluid return section includes a collecting hopper, an insulation blanket and a booster pump. The present invention utilizes the spectral modulation effect of quantum dots on solar energy to match the absorption spectrum of the working fluid with the solar spectrum, efficiently absorb solar energy, and thus realize a system and method for solar thermal storage, which is efficient, environmentally friendly, pollution-free, and has great development potential.

Description

Technical Field

[0001] The present invention relates to the field of solar energy storage technology, and specifically to a system and method for efficiently absorbing solar radiation energy and storing energy by utilizing quantum dot solar spectrum modulation technology and adopting special working fluids. Background Art

[0002] Environmental pollution and energy crisis are one of the prominent contradictions that restrict the sustainable development of my country's national economy. The efficient use of clean and renewable energy has become a top priority. As one of the main energy sources on the earth, solar energy has immeasurable development potential. If we can achieve efficient use of solar energy, we can not only reduce environmental pollution, but also achieve sustainable economic development.

[0003] At present, the main way to utilize solar energy is to first use materials with high absorption rates in the solar spectrum band to absorb solar energy and heat it up, then exchange heat with the working fluid by convection and heat conduction, and then the working fluid participates in the cycle to finally realize the utilization of solar energy. This process undergoes multiple energy conversions and has a low overall efficiency. Since the solar spectrum and the absorption spectrum of commonly used working fluids do not completely match, working fluids are rarely used directly to absorb solar energy except for large-scale solar power stations. Summary of the invention

[0004] Taking into account the limitations of traditional methods of utilizing solar energy, such as low efficiency and complex processes, the purpose of the present invention is to utilize the spectral modulation effect of quantum dots on solar energy to provide a solar thermal storage system and method based on quantum dot spectral modulation. The system and method are efficient, environmentally friendly, pollution-free, and can achieve efficient storage of solar energy.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A solar thermal storage system based on quantum dot spectrum modulation, the system consists of a special working fluid and pipeline, a working fluid spray evaporation section, a molten salt heat exchange section and a working fluid return section;

[0007] The special working fluid and pipeline include working fluid 1, small-diameter pipeline 2-1 and T-shaped pipeline 2-2, wherein working fluid 1 flows in small-diameter pipeline 2-1 and T-shaped pipeline 2-2, and the inlet and outlet of small-diameter pipeline 2-1 are respectively connected with the outlet and inlet of T-shaped pipeline 2-2 to form a closed loop; the working fluid 1 is a mixture of water and millimeter particles, and the millimeter particles are composed of a substrate and a thin layer of quantum dots wrapped around the substrate. The working fluid 1 after the millimeter particles are mixed with water has an absorption spectrum that matches the solar spectrum, thereby realizing efficient absorption of solar radiation; after the working fluid 1 is sprayed and evaporated, the millimeter particles can be separated from the steam and can be mixed with condensed water again;

[0008] The working fluid spray evaporation section includes a first solar concentrator 3-1, a nozzle 4 and a second solar concentrator 3-2. The first solar concentrator 3-1 is arranged on the side of the small-diameter pipeline 2-1 in front of the nozzle 4, the nozzle 4 is arranged at the connection between the outlet of the small-diameter pipeline 2-1 and the inlet of the T-shaped pipeline 2-2, and the second solar concentrator 3-2 is arranged on the side of the T-shaped pipeline 2-2 behind the nozzle 4.

[0009] The molten salt heat exchange part includes a molten salt tank 5, a molten salt pump 6 and a molten salt circulation pipeline 7. Part of the molten salt circulation pipeline 7 is built into the T-shaped pipeline 2-2. The inlet and outlet of the molten salt circulation pipeline 7 are connected to the molten salt tank 5. The molten salt pump 6 is arranged at the inlet of the molten salt circulation pipeline 7.

[0010] The working medium return section includes a collecting hopper 8, an insulation blanket 9 and a pressure pump 10. The collecting hopper 8 is arranged at the bottom outlet of the T-shaped pipeline 2-2, the pressure pump 10 is arranged on the small-diameter pipeline 2-1, and the insulation blanket 9 is arranged from the outlet of the collecting hopper 8 to the inlet of the pressure pump 10.

[0011] The substrate of the millimeter particles is made of silicon dioxide, paraffin, graphene or carbon-containing silica gel. The millimeter particles can absorb short-wave solar radiation with a wavelength of 400-800nm ​​and convert it into long-wave solar radiation with a wavelength of 1100-1500nm, thereby realizing solar spectrum modulation; the ratio between water and millimeter particles can be adjusted according to the required steam temperature.

[0012] The small-diameter pipeline 2-1 and the T-shaped pipeline 2-2 are both made of tempered glass doped with graphene and fired. While ensuring strength, they have a transmittance of up to 0.9 for sunlight and a low refractive index, and can fully reflect the radiation emitted by the working fluid 1 inside them.

[0013] The nozzle 4 adopts atomizing spray and is installed at the connection between the outlet of the small-diameter pipeline 2-1 and the inlet of the T-shaped pipeline 2-2 to ensure close contact and no leakage.

[0014] The first solar concentrator 3-1 and the second solar concentrator 3-2 use parabolic mirrors with different curvatures. By changing the installation positions of the parabolic mirrors, sunlight is focused on the small-diameter pipeline 2-1 and the T-shaped pipeline 2-2 to form a high-energy light beam.

[0015] The molten salt circulation pipeline 7 adopts an inclined pipeline in the inner part of the T-shaped pipeline 2-2, so as to facilitate the condensed water generated after the heat exchange between the molten salt and the steam to flow into the collecting hopper 8 along the wall of the T-shaped pipeline 2-2.

[0016] The working method of the solar thermal storage system based on quantum dot spectrum modulation comprises the following steps:

[0017] Step 1, preparation of special working fluid and pipeline: working fluid 1 is a mixture of water and millimeter particles in a preset ratio, the millimeter particles are composed of a substrate and a quantum dot thin layer wrapped around the substrate, and the small-diameter pipeline 2-1 and the T-shaped pipeline 2-2 are both made of tempered glass doped with graphene and fired;

[0018] Step 2, spray evaporation of the working fluid: the working fluid 1 passes through the booster pump 10 and the first solar concentrator 3-1 to form a high-temperature and high-pressure working fluid solution, and then passes through the nozzle 4 to form a conical water mist inside the T-shaped pipeline 2-2, and the second solar concentrator 3-2 continues to heat the droplets to evaporate and generate steam, which is separated from the millimeter particles; the millimeter particles enter the collecting hopper 8 under the action of gravity, and the steam moves upward under the action of buoyancy;

[0019] Step 3, molten salt heat exchange: the molten salt in the molten salt tank 5 is pressurized by the molten salt pump 6, enters the molten salt circulation pipeline 7, exchanges heat with the high-temperature steam inside the T-shaped pipeline 2-2, and then flows into the molten salt tank 5 again to form a closed loop;

[0020] Step 4, working medium returns: the high-temperature steam after heat exchange is condensed into liquid along the wall of T-shaped pipeline 2-2 and enters the collecting hopper 8 to mix with the millimeter particles again, enters the small-diameter pipeline 2-1 wrapped by the insulation blanket 9, and then enters the pressure pump 10, forming a closed-loop circulation of working medium 1.

[0021] The mass ratio of water to millimeter particles in working fluid 1 is (20-30):1.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The present invention uses a mixture of water and millimeter particles to modulate the spectrum of sunlight, so that the absorption spectrum of the working fluid matches the solar spectrum, thereby realizing the storage of solar energy. The system and method can realize efficient storage of solar energy, clean, environmentally friendly and sustainable, and can be applied to various industries that require energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Diagram of a solar thermal storage system based on quantum dot spectral modulation.

[0025] Figure 2 This is a simplified diagram of the structure of millimeter particles in the working fluid. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0027] like Figure 1As shown, a solar thermal storage system based on quantum dot spectral modulation is composed of a special working fluid and pipeline, a working fluid spray evaporation section, a molten salt heat exchange section and a working fluid return section; the special working fluid and pipeline include a working fluid 1, a small-diameter pipeline 2-1 and a T-shaped pipeline 2-2, wherein the working fluid 1 flows in the small-diameter pipeline 2-1 and the T-shaped pipeline 2-2, and the inlet and outlet of the small-diameter pipeline 2-1 are respectively connected to the outlet and inlet of the T-shaped pipeline 2-2 to form a closed loop; the working fluid spray evaporation section includes a first solar concentrator 3-1, a nozzle 4 and a second solar concentrator 3-2, the first solar concentrator 3-1 is arranged on the side of the small-diameter pipeline 2-1 in front of the nozzle 4, and the small-diameter pipeline 2-1 A nozzle 4 is arranged at the connection between the outlet and the inlet of the T-shaped pipeline 2-2, and the second solar concentrator 3-2 is arranged on the side of the T-shaped pipeline 2-2 behind the nozzle 4; the molten salt heat exchange part includes a molten salt tank 5, a molten salt pump 6 and a molten salt circulation pipeline 7, part of the molten salt circulation pipeline 7 is built into the T-shaped pipeline 2-2, the inlet and outlet of the molten salt circulation pipeline 7 are connected to the molten salt tank 5, and the molten salt pump 6 is arranged at the inlet of the molten salt circulation pipeline 7; the working medium return section includes a collecting hopper 8, an insulation blanket 9 and a pressure pump 10, the collecting hopper 8 is arranged at the bottom outlet of the T-shaped pipeline 2-2, the pressure pump 10 is arranged on the small-diameter pipeline 2-1, and the insulation blanket 9 is arranged from the outlet of the collecting hopper 8 to the inlet of the pressure pump 10.

[0028] The working medium 1 is a mixture of water and millimeter particles, the millimeter particles are composed of a substrate and a thin layer of quantum dots wrapped around the substrate, and the working medium 1 after the millimeter particles and water are mixed has an absorption spectrum that matches the solar spectrum, achieving efficient absorption of solar radiation; after the working medium 1 is sprayed and evaporated, the millimeter particles can be separated from the steam and can be mixed with the condensed water again; Figure 2 As shown, the millimeter particles are composed of a substrate and a thin layer of quantum dots wrapped around the substrate, and the millimeter particles can absorb short-wave (400-800nm) solar radiation and convert it into long-wave (1100-1500nm) solar radiation to achieve solar spectrum modulation. Preferably, the substrate in the millimeter particles is made of silicon dioxide, paraffin, graphene or carbon-containing silica gel.

[0029] Example 1: Solar energy storage on sunny days:

[0030] (1) Figure 1 As shown, preparation of special working fluid and pipeline: working fluid 1 is a mixture of water and millimeter particles in a mass ratio of 30:1, the millimeter particles are composed of a substrate and a quantum dot thin layer wrapped around the substrate, and the substrate in the millimeter particles in this embodiment is silicon dioxide, and the small-diameter pipeline 2-1 and the T-shaped pipeline 2-2 are both made of tempered glass doped with graphene and fired;

[0031] (2) Figure 1As shown, the working fluid spray evaporates: the working fluid 1 passes through the booster pump 10 and the first solar concentrator 3-1 to form a high-temperature and high-pressure working fluid solution, and then passes through the nozzle 4 to form a conical water mist inside the T-shaped pipeline 2-2, and the second solar concentrator 3-2 continues to heat the droplets to evaporate, forming steam with a temperature of about 300°C, and separates from the millimeter particles; the millimeter particles enter the collecting hopper 8 under the action of gravity, and the steam moves upward under the action of buoyancy;

[0032] (3) Figure 1 As shown, molten salt heat exchange: the molten salt in the molten salt tank 5 is pressurized by the molten salt pump 6, enters the molten salt circulation pipeline 7, and exchanges heat with the high-temperature steam of about 300°C inside the T-shaped pipeline 2-2, and then adjusts the molten salt pump power. When the molten salt temperature rises to 240°C, it flows into the molten salt tank 5 again to form a closed loop;

[0033] (4) Figure 1 As shown, the working medium returns: the high-temperature steam after heat exchange is condensed into a liquid with a temperature of about 70°C, flows into the collecting hopper 8 along the T-shaped pipeline 2-2, mixes with the millimeter particles, enters the small-diameter pipeline 2-1 wrapped by the insulation blanket 9, and then enters the pressure pump 10, forming a closed-loop circulation of the working medium 1.

[0034] Example 1: Solar energy storage on cloudy days:

[0035] (1) Figure 1 As shown, preparation of special working fluid and pipeline: working fluid 1 is a mixture of water and millimeter particles in a mass ratio of 20:1, the millimeter particles are composed of a substrate and a quantum dot thin layer wrapped around the substrate, and the substrate in the millimeter particles in this embodiment is graphene, and the small-diameter pipeline 2-1 and the T-shaped pipeline 2-2 are both made of tempered glass doped with graphene and fired;

[0036] (2) Figure 1 As shown, the working fluid spray evaporates: the working fluid 1 passes through the booster pump 10 and the first solar concentrator 3-1 to form a high-temperature and high-pressure working fluid solution, and then passes through the nozzle 4 to form a conical water mist inside the T-shaped pipeline 2-2, and the second solar concentrator 3-2 continues to heat the droplets to evaporate, forming steam with a temperature of about 240°C, and separates from the millimeter particles; the millimeter particles enter the collecting hopper 8 under the action of gravity, and the steam moves upward under the action of buoyancy;

[0037] (3) Figure 1 As shown, molten salt heat exchange: the molten salt in the molten salt tank 5 is pressurized by the molten salt pump 6, enters the molten salt circulation pipeline 7, and exchanges heat with the high-temperature steam of about 240°C inside the T-shaped pipeline 2-2, and then adjusts the molten salt pump power. When the molten salt temperature rises to 200°C, it flows into the molten salt tank 5 again to form a closed loop;

[0038] (4) Figure 1 As shown, the working medium returns: the high-temperature steam after heat exchange is condensed into a liquid with a temperature of about 60°C, flows into the collecting hopper 8 along the T-shaped pipeline 2-2, mixes with the millimeter particles, enters the small-diameter pipeline 2-1 wrapped by the insulation blanket 9, and then enters the pressure pump 10, forming a closed-loop circulation of the working medium 1.

Claims

1. A solar thermal storage system based on quantum dot spectral modulation, characterized in that: The system consists of special working fluid and pipeline, working fluid spray evaporation section, molten salt heat exchange section and working fluid return section; The special working fluid and pipeline include a working fluid (1), a small-diameter pipeline (2-1) and a T-shaped pipeline (2-2), wherein the working fluid (1) flows in the small-diameter pipeline (2-1) and the T-shaped pipeline (2-2), and the inlet and outlet of the small-diameter pipeline (2-1) are respectively connected to the outlet and inlet of the T-shaped pipeline (2-2), so as to form a closed loop; the working fluid (1) is formed by a mixture of water and millimeter particles, the millimeter particles are composed of a substrate and a quantum dot thin layer wrapped around the substrate, and the working fluid (1) after the millimeter particles and water are mixed has an absorption spectrum that matches the solar spectrum, thereby achieving efficient absorption of solar radiation; after the working fluid (1) is sprayed and evaporated, the millimeter particles can be separated from the steam and can be mixed with condensed water again; The working fluid spray evaporation section comprises a first solar concentrator (3-1), a nozzle (4) and a second solar concentrator (3-2); the first solar concentrator (3-1) is arranged on the side of the small-diameter pipeline (2-1) in front of the nozzle (4); the nozzle (4) is arranged at the connection between the outlet of the small-diameter pipeline (2-1) and the inlet of the T-shaped pipeline (2-2); and the second solar concentrator (3-2) is arranged on the side of the T-shaped pipeline (2-2) behind the nozzle (4); The molten salt heat exchange unit comprises a molten salt tank (5), a molten salt pump (6) and a molten salt circulation pipeline (7); part of the molten salt circulation pipeline (7) is built into the T-shaped pipeline (2-2); the inlet and outlet of the molten salt circulation pipeline (7) are connected to the molten salt tank (5); and the molten salt pump (6) is arranged at the inlet of the molten salt circulation pipeline (7); The working medium return section comprises a collecting hopper (8), a heat-insulating blanket (9) and a pressure pump (10); the collecting hopper (8) is arranged at the bottom outlet of the T-shaped pipeline (2-2); the pressure pump (10) is arranged on the small-diameter pipeline (2-1); and the heat-insulating blanket (9) is arranged from the outlet of the collecting hopper (8) to the inlet of the pressure pump (10); The base of the millimeter particles is made of silicon dioxide, paraffin, graphene or carbon-containing silica gel. The millimeter particles can absorb short-wave solar radiation with a wavelength of 400-800nm ​​and convert it into long-wave solar radiation with a wavelength of 1100-1500nm, thereby realizing solar spectrum modulation. The ratio between water and millimeter particles is adjusted according to the required steam temperature. The small-diameter pipeline (2-1) and the T-shaped pipeline (2-2) are both made of tempered glass doped with graphene and fired, and while ensuring strength, have a transmittance of up to 0.9 for sunlight, a low refractive index, and can fully reflect the radiation emitted by the working fluid (1) therein; The nozzle (4) adopts atomizing spray and is installed at the connection between the outlet of the small-diameter pipeline (2-1) and the inlet of the T-shaped pipeline (2-2) to ensure close contact and no leakage; The first solar concentrator (3-1) and the second solar concentrator (3-2) use parabolic mirrors with different curvatures, and by changing the installation positions of the parabolic mirrors, sunlight is focused on the small-diameter pipeline (2-1) and the T-shaped pipeline (2-2), thereby forming a high-energy light beam.

2. A solar thermal storage system based on quantum dot spectral modulation according to claim 1, characterized in that: The molten salt circulation pipeline (7) uses an inclined pipeline in the internal part of the T-shaped pipeline (2-2), so that the condensed water generated after the heat exchange between the molten salt and the steam can flow into the collecting hopper (8) along the wall of the T-shaped pipeline (2-2).

3. A working method of a solar thermal storage system based on quantum dot spectral modulation according to claim 1 or 2, characterized in that: The following steps are involved: Step 1, preparation of special working fluid and pipeline: the working fluid (1) is a mixture of water and millimeter particles in a preset ratio, the millimeter particles are composed of a substrate and a thin layer of quantum dots wrapped around the substrate, and the small-diameter pipeline (2-1) and the T-shaped pipeline (2-2) are both made of tempered glass doped with graphene and fired; Step 2, spray evaporation of the working fluid: the working fluid (1) passes through the pressure pump (10) and the first solar concentrator (3-1) to form a high-temperature and high-pressure working fluid solution, and then passes through the nozzle (4) to form a conical water mist inside the T-shaped pipeline (2-2), and the second solar concentrator (3-2) continues to heat the droplets to evaporate and generate steam, which is separated from the millimeter particles; the millimeter particles enter the collecting hopper (8) under the action of gravity, and the steam moves upward under the action of buoyancy; Step 3, molten salt heat exchange: the molten salt in the molten salt tank (5) is pressurized by the molten salt pump (6), enters the molten salt circulation pipeline (7), exchanges heat with the high-temperature steam inside the T-shaped pipeline (2-2), and then flows into the molten salt tank (5) again, forming a closed loop; Step 4, working medium return: After heat exchange, the high-temperature steam condenses into liquid and flows along the wall of the T-shaped pipeline (2-2) into the collecting hopper (8) to be mixed with the millimeter particles again, and then enters the small-diameter pipeline (2-1) wrapped by the insulation blanket (9), and then enters the pressure pump (10), forming a closed-loop circulation of the working medium (1).

4. The working method according to claim 3, characterized in that: The mass ratio of water to millimeter particles in the working fluid (1) is (20~30):1.

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