A light-controlled molecular heterogeneous thermal storage device

Abstract

This invention discloses a light-controlled molecular heterogeneous thermal storage device, belonging to the field of solar energy storage technology. The device includes a detachably connected first and second shell, both with mirrored inner surfaces. The first shell houses a light source assembly containing a xenon lamp and a first filter; the second shell has a magnetically attachable second filter on its top and multiple circular flow heat exchange channels running through its sides. A rotatable heat storage layer is fitted around each channel, and the interior is filled with a molecular light-switching material. A liquid metal thermally conductive layer is filled between the heat storage layer and the heat exchange channels. This invention achieves switching between natural light and auxiliary light modes through a detachable structure, adapting to different lighting conditions and enabling all-day operation; the rotating heat storage layer and mirrored inner wall ensure uniform illumination, and the liquid metal ensures efficient heat transfer, thereby significantly improving the energy storage and release efficiency of the molecular light-switching material and the system's controllability.

Description

Technical Field

[0001] This application relates to the field of solar energy storage technology, specifically to a light-controlled molecular heterogeneous thermal energy storage device. Background Technology

[0002] With the continuous growth of global energy demand and increasing emphasis on environmental protection, the development and utilization of clean and renewable solar energy has become an important way to solve the energy crisis and environmental pollution problems. Solar energy utilization technologies are mainly divided into two major directions: photoelectric conversion and photothermal conversion. However, the intermittency and instability of solar energy limit its direct and continuous application. Therefore, efficient, controllable, and stable energy storage technologies have become a key link in realizing the large-scale utilization of solar energy. Currently, common solar energy storage methods include battery energy storage, phase change material thermal storage, and chemical thermal storage. While these technologies each have their advantages, they also have certain limitations. For example, batteries have limited lifespan, high material costs, or environmental pollution risks; phase change materials have relatively limited thermal storage density, and the energy release process is not easy to control precisely. Thermochemical energy storage based on reversible chemical reactions usually requires high trigger temperatures or faces challenges such as the stability of reactant cycling. Therefore, exploring new principles of solar energy storage technologies, especially those that can directly capture, store, and release light energy on demand at the molecular scale, has significant scientific value and application prospects.

[0003] Photoinduced isomerization energy storage is a molecular solar energy storage technology that has attracted much attention in recent years. Azobenzene and its derivatives are typical photoresponsive molecules. When the azo bonds in their molecular structure absorb light of a specific wavelength, they can transform from a stable trans conformation to a metastable cis conformation. This process is accompanied by a significant increase in internal molecular energy, thus storing light energy as molecular potential energy. When another wavelength of light is applied, the cis conformation can revert to the trans conformation, releasing the stored energy as heat. This molecular battery concept based on phototriggered molecular isomerization theoretically possesses potential advantages such as high energy density, long energy storage time, recyclability, and precise and controllable energy release triggered by light signals.

[0004] However, transforming the microscopic molecular phenomenon of azobenzene photoisomerization into a macroscopically practical, efficient, and stable energy storage device still faces numerous technical challenges. The photoresponse band of the azobenzene molecule has limited matching with the solar spectrum, hindering improvements in energy storage efficiency. Furthermore, efficiently collecting, transferring, and outputting the energy stored at the molecular scale as usable thermal energy involves complex material design and system integration. Simultaneously, the cyclic stability, fatigue resistance, and isomerization efficiency in solid-state or composite materials directly affect the long-term operational lifespan and reliability of the device. However, existing research largely focuses on the materials themselves, lacking integrated system designs for intelligent management and control of the energy storage / release process. Summary of the Invention

[0005] This invention provides a novel light-controlled molecular heterogeneous thermal storage device, which aims to solve the technical problems faced by existing molecular light-switching materials in macroscopic energy storage systems, such as uneven illumination, low thermal management efficiency, and limitations imposed by the intermittency of natural light, so as to achieve higher efficiency and more stable and controllable energy storage and release.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] A light-controlled molecular heterogeneous thermal storage device includes a first shell and a second shell that are detachably connected. The bottom of the first shell and the top of the second shell are inclined toward each other, and all inner surfaces of both shells are mirrored.

[0008] The first housing has a circular hole and a straight groove at the top center. A sliding slider is provided on the straight groove, and a first filter is installed on the slider. A xenon lamp is connected to the outside of the circular hole.

[0009] The top of the second housing is provided with a magnetically attachable second filter, and multiple circular flow heat exchange channels run through its side.

[0010] A rotatable heat storage layer is fitted around the circular flow heat exchange channel. The heat storage layer is filled with molecular optical switching material, and the gap between its inner wall and the outer wall of the circular flow heat exchange channel is filled with a liquid metal heat-conducting layer.

[0011] Furthermore, the first and second housings are made of aluminum alloy, and the outer surfaces of the first and second housings are provided with thermal insulation cotton to reduce heat loss.

[0012] Furthermore, magnetic blocks are provided at the bottom of the first housing and the top of the second housing for disassembly and assembly of the housing.

[0013] Furthermore, by disassembling and installing the first housing, the device can be configured into two different combined structures: the first combined structure includes the second housing and a second filter mounted on its top; the second combined structure includes the first housing and the second housing connected together, as well as the xenon lamp and the first filter mounted on the slider.

[0014] Furthermore, the outer shell structure combining the second housing and the second filter is suitable for applications with solar radiation intensity exceeding 600 W / m². 2 During the specified time period of use, the housing structure comprising the first housing, the second housing, the first filter, the slider, and the xenon lamp assembly operates at night and under solar radiation intensity below 600 W / m². 2 Used within a specified time period.

[0015] Furthermore, the circular flow heat exchange channel is made of copper, has a wall thickness of 5 mm, has 4 to 11 channels, an inner diameter of 10 to 50 mm, a length of 200 to 600 mm, and a distance of 100 to 200 mm between the circular flow heat exchange channel and the top of the first shell.

[0016] Furthermore, the inner surface of the heat storage layer is made of copper, the outer surface and both ends of the heat storage layer are made of transparent acrylic sheets, and the outer diameter of the heat storage layer is 5-20 mm.

[0017] Furthermore, the molecular optical switch material filled inside the heat storage layer is azobenzene and its derivatives.

[0018] Furthermore, the liquid metal filled in the gap between the inner wall of the heat storage layer and the outer wall of the circular flow heat exchange channel is gallium, gallium-indium alloy, gallium-indium-tin alloy, etc.

[0019] The beneficial effects of this invention are as follows:

[0020] (1) The present invention can freely assemble the shell according to the solar radiation intensity, organically combine solar energy and xenon lamp illumination, realize efficient application at all times, and overcome the limitations of the intermittency and instability of solar energy on energy storage devices.

[0021] (2) The present invention adopts a structure in which the heat storage layer covers the flow heat exchange channel and connects the heat storage layer to the rotating shaft. When the molecular optical switch material is photo-isomerized, the rotating shaft drives the heat storage layer to rotate at a constant speed, so that the molecular optical switch material is uniformly illuminated, avoiding local hot spots caused by excessive local illumination intensity, thereby reducing the isomerization rate. At the same time, the inner wall surface of the shell is set as a mirror, which maximizes the use of the light source through the reflection principle and greatly improves the isomerization efficiency of the molecular optical switch material.

[0022] (3) The molecular optical switch material is selected from azobenzene and its derivatives, which can respond quickly within 2 minutes, realize cis-trans isomerization and thus realize energy storage and release. The isomerization rate is as high as 80% to 95%, the cycle performance is good, and the half-life can reach 10 hours to 1 year. The molecular optical switch material can be filled according to the application scenario requirements.

[0023] (4) The gap between the inner wall of the heat storage layer and the outer wall of the circular flow heat exchange channel is filled with gallium-based liquid metal with both low melting point and high thermal conductivity. The thermal conductivity is 5 times that of traditional thermal grease, and it can remain liquid in a low temperature environment to ensure effective heat transfer between the walls. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure under light source illumination according to a specific embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure under sunlight according to a specific embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the pipeline structure according to a specific embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the filter module structure according to a specific embodiment of the present invention;

[0028] In the figure: 1-First housing; 2-Second housing; 3-First filter; 4-Linear chute; 5-Xenon lamp; 6-Second filter; 7-Circular flow heat exchange channel; 8-Heat storage layer; 9-Rotating shaft. Detailed Implementation

[0029] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0030] The light-controlled molecular heterogeneous thermal storage device of the present invention includes a first housing 1 and a second housing 2 that are detachably connected. The bottom of the first housing 1 and the top of the second housing 2 are inclined at 30 degrees. All inner surfaces of the first housing 1 and the second housing 2 are mirrored. A circular hole and a linear groove 4 are provided at the center of the top of the first housing 1. A sliding slider is provided on the linear groove 4. A first filter (circular) 3 is provided inside the hole and connected to the slider. A xenon lamp 5 is connected to the outside of the hole. A second filter (square) 6 is magnetically attached to the top of the second housing 2. Multiple circular flow heat exchange channels 7 penetrate the side of the second housing 2. A rotatable thermal storage layer 8 is provided around the periphery of the circular flow heat exchange channels 7. The two ends of the thermal storage layer 8 are connected to the rotating shafts 9. The rotating shafts 9 are externally connected to a motor. The interior of the thermal storage layer 8 is filled with a molecular light-switching material. The gap between the inner wall of the thermal storage layer 8 and the outer wall of the circular flow heat exchange channels 7 is filled with liquid metal.

[0031] In one specific embodiment, the first shell 1 and the second shell 2 form a square shell with a length, width, and height of 300 mm and a wall thickness of 10 mm. The first shell 1 and the second shell 2 are made of aluminum alloy, and the outer surfaces of the first shell 1 and the second shell 2 are covered with thermal insulation cotton with a thermal conductivity of 0.035 W / (m·K). Magnetic blocks are provided at the bottom of the first shell 1 and the top of the second shell 2 for quick assembly and separation of the two.

[0032] The device can operate in two configurations depending on the lighting conditions: when the solar radiation intensity is higher than 600 W / m 2 When assembling the second housing 2 and the second filter 6, it is used; when the solar radiation intensity is below 600 W / m 2 When assembling the first housing 1, the second housing 2, the first filter 3, the slider, and the xenon lamp 5, it is used.

[0033] The circular flow heat exchange channel 7 is made of copper with a wall thickness of 5 mm. It consists of 11 channels, each with an inner diameter of 30 mm and a length of 300 mm. To ensure efficient use of the light source and avoid localized overheating, the distance between the central axis of the circular flow heat exchange channel 7 and the top inner wall of the first housing 1 is set to 150 mm.

[0034] The inner surface of the heat storage layer 8 is made of copper, closely adhering to the outer surface of the circular flow heat exchange channel 7. Its outer surface and both ends are made of transparent acrylic sheets. The outer diameter of the heat storage layer 8 is 10 mm. To reduce heat transfer efficiency, the gap between the inner wall of the heat storage layer 8 and the outer wall of the circular flow heat exchange channel 7 is filled with liquid gallium-indium alloy, which has a thermal conductivity of 26 W / (m·K), a melting point of 16.7℃, a boiling point >1000℃, and a density of 6335 kg / m³. 3 .

[0035] The molecular optical switch material filled inside the thermal storage layer 8 is azobenzene phase change material. Under 365 nm wavelength light irradiation, it can complete the isomerization from trans to cis structure within 60 seconds, i.e., the energy storage process, with an isomerization rate of 95%; and under 450 nm wavelength light irradiation, it can complete the isomerization from cis to trans structure within 60 seconds, i.e., the energy release process, with an isomerization rate of 90%. After 50 cycles, the cis-trans isomerization decay rate is 0.03%. The crystallization temperature of the cis structure is -28℃, the crystallization temperature of the trans structure is 49℃, the melting temperature of the cis structure is 28℃, and the melting temperature of the trans structure is 64℃. The isomerization release enthalpy from cis to trans structure is 111 kJ / kg and the phase transition enthalpy is 99 kJ / kg, with a total energy storage density as high as 210 kJ / kg, which is 1.5 times higher than that of pure azobenzene.

[0036] The specific working principle of the light-controlled molecular heterogeneous thermal storage device in this embodiment is as follows:

[0037] When the solar radiation intensity is higher than 600 W / m 2When energy storage is required, the second housing 2 and the second filter 6 are assembled. The second filter 6 uses a 365 nm wavelength, the motor is started to drive the rotating shaft 9 to rotate the heat storage layer 8 at a constant speed, and the device is placed under sunlight. The molecular photo-switching material within the heat storage layer 8 undergoes an isomerization process from trans to cis, and energy is stored within the cis molecular photo-switching material. When energy release is required, the second filter 6 is switched to a 450 nm wavelength, the motor is started to drive the rotating shaft 9 to rotate the heat storage layer 8 at a constant speed, and the device is placed under sunlight. The molecular photo-switching material within the heat storage layer 8 undergoes an isomerization process from cis to trans, and energy is released from the cis molecular photo-switching material. The released heat is transferred to the liquid metal in the gap between the outer surface of the circular flow heat exchange channel 7 and the inner surface of the heat storage layer 8. The liquid metal then rapidly transfers the heat to the flowing working fluid within the circular flow heat exchange channel 7. After the energy release is complete, the cis molecular photo-switching material reverts to the trans structure for new energy storage.

[0038] When the solar radiation intensity is below 600 W / m 2 During assembly, the first housing 1, the second housing 2, the first filter 3, the slider, and the xenon lamp 5 are assembled. When energy storage is required, the slider is switched to the first filter 3 with a wavelength of 365 nm, the motor is started to drive the rotating shaft 9 to rotate the heat storage layer 8 at a constant speed, and the xenon lamp 5 is turned on to illuminate the heat storage layer 8. The molecular photo-switching material in the heat storage layer 8 completes the isomerization process from trans to cis, and the energy is stored in the cis molecular photo-switching material. When energy release is required, the sliding slider switches to the first filter 3 with a wavelength of 450 nm, the motor starts and drives the rotating shaft 9 to rotate the heat storage layer 8 at a constant speed, and the xenon lamp 5 is turned on to illuminate the heat storage layer 8. The molecular photo-switching material in the heat storage layer 8 completes the isomerization process from cis to trans, and energy is released from the cis molecular photo-switching material. The released heat is transferred to the liquid metal in the gap between the outer surface of the circular flow heat exchange channel 7 and the inner surface of the heat storage layer 8. The liquid metal then quickly transfers the heat to the flowing working fluid in the circular flow heat exchange channel 7. After the energy release is completed, the cis molecular photo-switching material returns to the trans structure to store new energy.

[0039] The above specific embodiments are only for illustrating the technical concept and structural features of the present invention, and are intended to enable those skilled in the art to implement them. However, the above content does not limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit and essence of the present invention should fall within the scope of protection of the present invention.

Claims

1. A light-controlled molecular heterogeneous thermal storage device, characterized in that, It includes a first housing (1) and a second housing (2) that are detachably connected. The bottom of the first housing (1) and the top of the second housing (2) are inclined toward each other, and all the inner surfaces of both are mirrored. The first housing (1) has a circular hole and a straight groove (4) at the top center. A sliding slider is provided on the straight groove (4), and a first filter (3) is installed on the slider. A xenon lamp (5) is connected to the outside of the circular hole. The second housing (2) has a magnetically attachable second filter (6) on its top, and multiple circular flow heat exchange channels (7) run through its side. The circular flow heat exchange channel (7) is surrounded by a rotatable heat storage layer (8). The heat storage layer (8) is filled with molecular optical switching material, and the gap between its inner wall and the outer wall of the circular flow heat exchange channel (7) is filled with a liquid metal heat-conducting layer.

2. The light-controlled molecular heterogeneous thermal storage device as described in claim 1, characterized in that, The first housing (1) and the second housing (2) are made of aluminum alloy, and the outer surfaces of the first housing (1) and the second housing (2) are provided with thermal insulation cotton.

3. The light-controlled molecular heterogeneous thermal storage device as described in claim 1, characterized in that, Magnetic blocks are provided at corresponding positions on the bottom of the first housing (1) and the top of the second housing (2), so that the two can be connected and separated by magnetic force, thereby forming the detachable connection.

4. The light-controlled molecular heterogeneous thermal storage device as described in claim 1, characterized in that, By disassembling and installing the first housing (1), the device can form two different combined structures: the first combined structure includes the second housing (2) and the second filter (6) mounted on its top; the second combined structure includes the first housing (1) and the second housing (2) connected together, as well as the xenon lamp (5) and the first filter (3) mounted on the slider.

5. The light-controlled molecular heterogeneous thermal storage device as described in claim 1, characterized in that, The circular flow heat exchange channel (7) is made of copper, with a wall thickness of 5 mm, and there are 4 to 11 channels. The inner diameter of the channel is 10 to 50 mm, and the length of the circular flow heat exchange channel (7) is 200 to 600 mm.

6. The light-controlled molecular heterogeneous thermal storage device as described in claim 1 or 5, characterized in that, The distance between the circular flow heat exchange channel (7) and the top of the first shell (1) is 100-200 mm.

7. The light-controlled molecular heterogeneous thermal storage device as described in claim 1, characterized in that, The inner surface of the heat storage layer (8) is made of copper, the outer surface and both ends of the heat storage layer (8) are made of transparent acrylic sheets, and the outer diameter of the heat storage layer (8) is 5 to 20 mm.

8. The light-controlled molecular heterogeneous thermal storage device as described in claim 1, characterized in that, The molecular photo-switching material filled inside the heat storage layer (8) is azobenzene and its derivatives.

9. The light-controlled molecular heterogeneous thermal storage device as described in claim 1, characterized in that, The liquid metal filled in the gap between the inner wall of the heat storage layer (8) and the outer wall of the circular flow heat exchange channel (7) is gallium, gallium-indium alloy or gallium-indium-tin alloy.

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