A core-shell structure high-temperature photothermal phase change heat storage particle and a preparation method and application thereof

Abstract

The application discloses a kind of core-shell structure high-temperature photo-thermal phase change heat storage particles and its preparation method and application, the particle is composed of core material and shell;The core material is white spherical particle with magnesium oxide and hexagonal boron nitride as skeleton, carrying sodium chloride-potassium chloride eutectic salt;The shell is manganese iron black.The core-shell structure high-temperature photo-thermal phase change heat storage particles of the application has the characteristics of high-temperature photo-thermal conversion and phase change heat storage integration, the thermal conductivity of particle material is obviously improved, the heat storage density is higher, solar spectrum absorption rate is strong, and the cycle stability is good, can realize continuous efficient high-temperature solar photo-thermal conversion and phase change heat storage in flow state.

Description

TECHNICAL FIELD

[0001] The present application relates to a phase change heat storage material, in particular to a core-shell structure high-temperature photo-thermal phase change heat storage particle and a preparation method and application thereof. BACKGROUND

[0002] With the continuous increase of energy consumption, the traditional energy has intensified the energy crisis due to environmental pollution and limited reserves, so efficient use of solar energy, a clean and abundant renewable energy, becomes the key to alleviate the crisis. Solar thermal conversion technology is a direct and efficient solar energy utilization technology, which has the advantages of low cost and small pollution in production process. However, solar energy has the problems of intermittency and volatility, and heat storage technology is one of the key technologies to overcome this challenge. Phase change heat storage technology can effectively alleviate the intermittency of solar energy due to its stable heat storage / heat release temperature, high energy density and abundant heat storage phase change material. The combination of solar thermal conversion and phase change heat storage technology realizes zero-carbon emission of heat storage. Compared with indirect solar heat utilization technology, the integration of solar thermal conversion and phase change heat storage technology can reduce the heat transfer link and realize more efficient solar energy collection. However, the application temperature and heat storage capacity of the existing integrated photo-thermal conversion and phase change energy storage material are limited, and the energy storage density is low, the material is easy to collapse, the spectral absorption rate is low, and the cost is high. SUMMARY

[0003] The first object of the present application is to provide a core-shell structure high-temperature photo-thermal phase change heat storage particle with high-temperature photo-thermal conversion and phase change heat storage integration, which improves the application temperature, energy storage density, high compressive strength, spectral absorption rate and reduces the cost. The second object of the present application is to provide a preparation method of the core-shell structure high-temperature photo-thermal phase change heat storage particle. The third object of the present application is to provide an application of the core-shell structure high-temperature photo-thermal phase change heat storage particle.

[0004] Technical solution: The core-shell structure high-temperature photo-thermal phase change heat storage particle comprises a core material and a shell; the core material is a white spherical particle with magnesium oxide and hexagonal boron nitride as the framework and sodium chloride-potassium chloride eutectic salt as the load; and the shell is manganese-iron black.

[0005] The shell manganese-iron black has higher spectral absorption performance and stronger solar energy capture ability in the visible light band, and the photo-thermal conversion rate is higher. The core material has higher thermal conductivity and faster heat absorption and release speed, and has high heat storage density and high strength. The core material and the manganese-iron black shell layer realize the integration of photo-thermal conversion and phase change energy storage through synergistic effect, absorb light energy through the shell to convert into heat energy, use the continuous framework structure of the core material magnesium oxide to conduct heat energy quickly, and store it in the composite phase change material.

[0006] The magnesium oxide in the core material provides a continuous skeleton, improves the thermal conductivity and anti-leakage deformation capacity of the composite phase change material; the hexagonal boron nitride improves the compression strength and anti-leakage deformation capacity of the composite phase change material; and the sodium chloride-potassium chloride eutectic salt improves the application temperature, energy storage density and reduces the cost.

[0007] Preferably, in the core material, the content of the magnesium oxide is 45-48% by mass fraction, the content of the hexagonal boron nitride is 5-10% by mass fraction, and the content of the sodium chloride-potassium chloride eutectic salt is 45-48% by mass fraction.

[0008] Preferably, in the core material, the particle size of the core-shell structure high-temperature light-heat phase change heat storage particles is 1-2 mm.

[0009] Preferably, the content of the core material is 80-90% by mass fraction, and the content of the shell is 10-20% by mass fraction.

[0010] The preparation method of the core-shell structure high-temperature light-heat phase change heat storage particles comprises the following steps:

[0011] (1) The magnesium oxide, hexagonal boron nitride and sodium chloride-potassium chloride eutectic salt are placed in a ball mill for mixing, a binder solution is added, and the mixture is fully stirred and uniformly mixed to form a wet material;

[0012] (2) The wet material is put into an extruder to form a strip-shaped material by extrusion;

[0013] (3) The strip-shaped mixture is dispersed into segments, and the segments are put into a rolling machine to form particles, which are collected and dried;

[0014] (4) The particles are added to a binder solution, and then manganese-iron black powder is added for coating until the manganese-iron black powder is uniformly coated on the surface of the particles to obtain black particles, which are taken out;

[0015] (5) The black particles are calcined to remove the binder to obtain the core-shell structure high-temperature light-heat phase change heat storage particles.

[0016] Preferably, in step (1), the rotation speed of the ball mill is set to 300-400 r / min, and the ball milling time is 1-2 h.

[0017] The preparation method of the sodium chloride-potassium chloride eutectic salt comprises the following steps: mixing sodium chloride and potassium chloride, placing them in a ball mill for fully grinding to mix them uniformly, and placing them in an oven for fully drying to obtain the composite phase change particles. Preferably, the mass ratio of sodium chloride to potassium chloride is 1:1.30. Preferably, the rotation speed of the ball mill is set to 300 r / min, and the ball milling time is 2 h. Preferably, the drying temperature is 110°C, and the drying time is 4-5 h, so that the obtained eutectic chloride salt is completely dried and does not contain water.

[0018] Preferably, the adhesive is polyvinyl alcohol. The preparation method of polyvinyl alcohol solution is: weigh the polyvinyl alcohol powder according to the concentration, pour it into deionized water, paste the beaker with sealing film, place it in a water bath constant temperature magnetic stirrer, heat and stir to make it fully dissolved and uniform. Preferably, the temperature of the water bath constant temperature magnetic stirrer is set to 100℃, and the stirring time is 3-4h, under this condition, the polyvinyl alcohol powder can be completely dissolved. Preferably, the concentration of the polyvinyl alcohol solution is 3wt%.

[0019] Preferably, in step (1), the volume ratio of the adhesive solution to the powder is about 1:4, which can be increased or decreased slightly according to the situation, and the wet material under this condition is more suitable for extrusion.

[0020] Preferably, in step (2), the extrusion rate is 80RMP, under this condition, the extrusion speed is moderate and the forming rate is high.

[0021] Preferably, in step (3), the strip-shaped mixture is dispersed into the required segment for rolling by repeated kneading and sieving.

[0022] Preferably, in step (3), the air induction speed of the rolling machine is 1000-1200RMP, the air blowing speed is 800-1000RMP, the rotating disc speed is 80-100RPM, and the air inlet temperature is 30-50℃.

[0023] Preferably, in step (3), the drying temperature is 110℃, and the drying time is 4-5h.

[0024] Preferably, in step (4), the dried particles are put into the coating machine, the peristaltic pump is set to 4RMP, the air induction speed is 1200RMP, the air blowing speed is 1000RMP, the rotating disc speed is 100RPM, the air inlet temperature is 50℃, and the manganese iron black is uniformly scattered, the coating process lasts for 15-20min, under this condition, the coating effect is best and the distribution is uniform, which can further improve the anti-leakage performance.

[0025] Preferably, in step (5), the calcination temperature is 720-750℃, and the time is 4-5h.

[0026] The core-shell structure high-temperature photo-thermal phase change heat storage particles are applied in the integration of photo-thermal conversion and phase change heat storage.

[0027] Preferably, the core-shell structure high-temperature photo-thermal phase change heat storage particles are in a flowing state during the heat storage process. Further preferably, the application is to place the core-shell structure high-temperature photo-thermal phase change heat storage particles in a new mobile bed system.

[0028] Invention mechanism: Magnesium oxide and hexagonal boron nitride are both support materials, which play a role in constructing a continuous skeleton and supporting phase change materials, and at the same time provide capillary force to prevent leakage of phase change materials. Manganese iron black is coated on the outside of the core material by coating technology, and the high-purity shell improves the spectral absorption capacity. The binder solution is used for shaping and bonding during the preparation process and is gradually removed as it volatilizes with the increase of temperature. The heated liquid sodium chloride-potassium chloride eutectic salt not only replaces the adhesive to play a bonding role, but also provides the necessary capillary force to pull the magnesium oxide and hexagonal boron nitride materials, so that the support materials are closely gathered and rearranged, thereby forming a continuous and stable skeleton structure. During the cooling process after sintering is completed, the sodium chloride-potassium chloride eutectic salt gradually changes from a liquid to a solid, fully filling the gaps in the skeleton, enhancing the continuity and stability of the overall structure, and finally forming a stable shape composite phase change material.

[0029] Beneficial effects: Compared with the prior art, the present application has the following significant advantages: (1) By using magnesium oxide and hexagonal boron nitride as the skeleton material and carrying sodium chloride-potassium chloride eutectic salt to form the core material, manganese iron black as the shell, the spectral absorption performance is higher, the visible light band solar energy capture ability is strong, the light-thermal conversion energy storage efficiency is high, and the heat storage density is high; (2) The core-shell structure high-temperature light-thermal phase change heat storage particles are corrosion-resistant and have high phase change enthalpy; (3) The preparation method of extrusion rounding-mixing sintering is simple, can be mass produced, and has industrial application prospect; (4) The core-shell structure high-temperature light-thermal phase change heat storage particles can realize continuous and efficient heat storage in a flowing state. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The preparation flow chart of the present application;

[0031] Figure 2 The SEM image of the core-shell structure high-temperature light-thermal phase change heat storage particles prepared in Example 3;

[0032] Figure 3 The enthalpy value comparison chart of the high-temperature light-thermal phase change heat storage particles prepared in Example 3, Comparative Examples 1-4 and pure phase change materials;

[0033] Figure 4 The compressive strength comparison chart of the high-temperature light-thermal phase change heat storage particles prepared in Examples 1-2 and Comparative Example 1;

[0034] Figure 5 The thermal conductivity comparison chart of the high-temperature light-thermal phase change heat storage particles prepared in Example 3, Comparative Examples 1-4 and pure phase change materials;

[0035] Figure 6 The solar spectrum absorption rate comparison chart of the core material prepared in Example 1, the high-temperature light-thermal phase change heat storage particles prepared in Example 3 and pure manganese iron black;

[0036] Figure 7 Figure 3 is a diagram of the enthalpy, melting point, and mass cycle stability of the core-shell structure high-temperature photothermal phase change heat storage particles prepared in Example 3;

[0037] Figure 8 Figure 4 is a diagram of the specific heat test of the core-shell structure high-temperature photothermal phase change heat storage particles prepared in Example 3;

[0038] Figure 9 Figure 5 is a diagram of the photothermal conversion performance test of the core-shell structure high-temperature photothermal phase change heat storage particles prepared in Example 3 under different heat storage modes of flow state and static state. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be further described below in combination with examples.

[0040] Example 1

[0041] The core material of the core-shell structure high-temperature photothermal phase change heat storage particles of the present application contains 47.5% of magnesium oxide, 5% of hexagonal boron nitride, and 47.5% of sodium chloride-potassium chloride eutectic salt, and the preparation method comprises the following steps:

[0042] First step: preparation of high-temperature phase change material sodium chloride-potassium chloride eutectic salt.

[0043] According to the mass ratio of 1:1.30, sodium chloride and potassium chloride are weighed and mixed, placed in a ball mill, the ball mill speed is set to 300 r / min, the ball milling time is 2 hours, and the mixture is fully ground and mixed, then placed in an oven, the oven is set to 110℃, and the drying time is 5h to fully dry the moisture, and a binary eutectic phase change material is obtained.

[0044] Second step: preparation of binder.

[0045] Prepare a solution with a polyvinyl alcohol solution concentration of 3wt%: weigh the polyvinyl alcohol powder into the deionized water according to the concentration, cover the beaker with a sealing film, place it in a water bath constant temperature magnetic stirrer, set the water bath constant temperature magnetic stirrer temperature to 100℃, and stir for 4h to fully dissolve and mix evenly, obtaining a uniform polyvinyl alcohol solution.

[0046] Third step: preparation of core material.

[0047] (1) The hexagonal boron nitride, magnesium oxide, and eutectic salt obtained in the first step are weighed and mixed according to the mass ratio of 1:9.5:9.5, placed in a ball mill, the ball mill speed is set to 300 r / min, the ball milling time is 2 hours, and the mixture is fully mixed and evenly obtained; add 25% of the total mass of the mixed powder binder solution, fully stir and knead evenly, and make it into a wet material;

[0048] (2) Put the wet material into the extruder, set the extrusion rate to 80RMP, and make it into a strip shape by extrusion;

[0049] (3) Disperse the strip-shaped mixture into segments by repeated kneading and sieving, and put it into a roller compactor. Set the air induction speed of the roller compactor to 1200RMP, the air blowing speed to 1000RMP, the rotating disc speed to 100RPM, and the air inlet temperature to 50℃. After rolling, collect the particles. Put the particles into an oven, set the oven to 110℃, and dry for 5h to fully dry the moisture. The core material particles are obtained.

[0050] Example 2

[0051] The core material of the core-shell structure high-temperature light-heat phase change heat storage particles of the application contains 45% magnesium oxide, 10% hexagonal boron nitride, and 45% sodium chloride-potassium chloride eutectic salt by mass fraction.

[0052] The preparation method is the same as that in Example 1.

[0053] Example 3

[0054] The core-shell structure high-temperature light-heat phase change heat storage particles of the application contain 85.71% core material and 14.29% manganese iron black shell by mass fraction.

[0055] The core material is the same as in Example 1, and a shell is wrapped around the core material. The preparation method is as follows:

[0056] (1) Put the dry core material particles into a coating machine. The mass ratio of the dry core material particles to manganese iron black is 1:6. Set the peristaltic pump to 4RMP, spray 20% of the total mass of the core material with a binder solution, set the air induction speed to 1200RMP, the air blowing speed to 1000RMP, the rotating disc speed to 100RPM, and the air inlet temperature to 50℃. Uniformly sprinkle the manganese iron black into the coating process, which lasts for 15-20min. After the manganese iron black powder is evenly coated on the surface of the particles, black particles are obtained and taken out.

[0057] (2) Put the black particles into a muffle furnace, set the temperature rising program to 10℃ / min, and rise to 720℃. After 4h of heat preservation, naturally cool to room temperature. The core-shell structure high-temperature light-heat phase change heat storage particles with integrated high-temperature light-heat conversion and phase change heat storage are obtained, with a particle size of 1-2mm.

[0058] Comparative Example 1

[0059] On the basis of Example 1, no hexagonal boron nitride is added to the core material, and the other conditions remain unchanged.

[0060] Comparative Example 2

[0061] On the basis of Example 1, hexagonal boron nitride is not added in the core material, the content of magnesium oxide is changed to 30%, the content of sodium chloride-potassium chloride eutectic salt is changed to 70%, and the rest of the conditions remain unchanged.

[0062] Comparative Example 3

[0063] On the basis of Example 1, hexagonal boron nitride is not added in the core material, the content of magnesium oxide is changed to 40%, the content of sodium chloride-potassium chloride eutectic salt is changed to 60%, and the rest of the conditions remain unchanged.

[0064] Comparative Example 4

[0065] On the basis of Example 1, hexagonal boron nitride is not added in the core material, the content of magnesium oxide is changed to 60%, the content of sodium chloride-potassium chloride eutectic salt is changed to 40%, and the rest of the conditions remain unchanged.

[0066] Structural characterization

[0067] From Figure 2 It can be seen from Figures (a) and (d) that the microstructure images of the internal cross-section and the external surface of the particles are shown. It can be seen from the comparison of Figures (b) and (c) that the microstructure of the composite phase change material particles changes during the preparation process. The internal composition of the particles before sintering shows a uniform distribution of granular particles (Figure (b)), however, after high-temperature heat treatment, it can be clearly observed that the magnesium oxide crystals are transformed into a cubic structure, and a stable and continuous skeleton structure is formed (Figure (c)). Similarly, the comparison of Figures (e) and (f) can see that the shell structure of the composite phase change material particles forms a black manganese-iron black shell layer with a continuous structure outside the particles after sintering. At the same time, it can also be observed that the shell layer is distributed with pores, and these pore structures provide space for the volume change of the phase change material during the phase change process, preventing the original structure of the phase change material from being destroyed. This shell structure and the magnesium oxide crystals together form a continuous support skeleton, which provides a good guarantee for the shape stability of the eutectic salt in the molten state.

[0068] Performance test

[0069] 1. Enthalpy test

[0070] The enthalpy of the samples of Example 3, Comparative Examples 1-4 and pure sodium chloride-potassium chloride eutectic salt was tested.

[0071] Test method: The enthalpy of the sample was tested by using a high-temperature differential scanning calorimeter, and the test results are shown in Figure 3 .

[0072] From Figure 3It can be seen that the sodium chloride-potassium chloride phase change material has a melting point of 665℃, making it suitable for high-temperature applications and improving the application temperature. The enthalpy value of Example 3 is 159.19 kJ / kg. The enthalpy values ​​of Comparative Examples 1 to 4 are 265.05 kJ / kg, 230.27 kJ / kg, 188.96 kJ / kg, and 146.00 kJ / kg, respectively. The enthalpy value of the composite phase change material is directly proportional to the mass fraction of the phase change material in the composite material; as the content of the phase change material increases, the phase change enthalpy value of the composite material increases.

[0073] 2. Compressive strength test

[0074] The compressive strength of the samples from Examples 1-2 and Comparative Example 1 was tested.

[0075] Test method: The strength of the samples was determined using a manual precision compression testing machine, and the critical breaking pressure value of each sample was recorded. The test results are as follows: Figure 4 As shown.

[0076] Depend on Figure 4 The critical crushing pressure values ​​for Comparative Example 1 and Examples 1-2 were 18.93 N, 21.34 N, and 25.59 N, respectively. The critical crushing pressure value of the particles increased with the increase of the mass fraction of hexagonal boron nitride in the particles, indicating that the addition of hexagonal boron nitride can effectively improve the compressive strength and deformation resistance of the composite phase change material. However, excessive hexagonal boron nitride will make the material too hard and difficult to prepare and shape.

[0077] 3. Thermal conductivity test

[0078] The thermal conductivity of the samples from Example 3, Comparative Examples 1-4, and pure sodium chloride-potassium chloride eutectic salt was tested.

[0079] Test method: The thermal conductivity of the sample was tested using a laser thermal conductivity analyzer. The test results are as follows: Figure 5 As shown.

[0080] Depend on Figure 5 The thermal conductivity at room temperature for Comparative Examples 1-4 and Example 3 were 3.66 W / (m·K), 4.22 W / (m·K), 4.40 W / (m·K), 4.57 W / (m·K), and 6.84 W / (m·K), respectively. Compared to the thermal conductivity of the pure phase change material (2.6 W / (m·K), the average thermal conductivity of the composite phase change material was significantly improved, and it increased with the increase of magnesium oxide content, demonstrating the effect of magnesium oxide on enhancing the thermal conductivity of the composite material. Furthermore, manganese iron black and hexagonal boron nitride also further improved the thermal conductivity.

[0081] 4. Spectral Absorption Rate Test

[0082] The spectral absorbance of the samples from Examples 1 and 3 was tested.

[0083] Test method: The spectral absorption rate of the sample was tested by UV-visible spectrophotometer, and the test results are shown in Figure 6 .

[0084] From Figure 6 , the spectral absorption rate of pure manganese iron black is 92.70%, the spectral absorption rate of the particles without manganese iron black added in Example 1 is 41.81%, and the spectral absorption rate of the particles with manganese iron black added in Example 3 is close to that of pure manganese iron black, which is 91.12%, proving that the manganese iron black shell can greatly improve the spectral absorption capacity of the material.

[0085] 5. Cycle stability test

[0086] The cycle stability of the sample of Example 3 was tested.

[0087] Test method: A reciprocating furnace was used to test the cycle experiment, and the test results are shown in Figure 7 .

[0088] From Figure 7 , after 900 cycles of testing, the weight loss rate of the sample was only 2.95%, which is a small mass loss that can be accepted in practical applications. The enthalpy value of the composite phase change material of Example 3 gradually decreased from the initial 159.19 kJ / kg and stabilized at about 140 kJ / kg, while the melting point remained stable, always around 664℃, with no obvious change trend. The gradual stability of the enthalpy value and the mass change show that the prepared composite material has excellent thermal stability and can withstand 900 cycles of use in the temperature range of 500-700℃.

[0089] 6. Specific heat test

[0090] The specific heat of the sample of Example 3 was tested.

[0091] Test method: The high-temperature specific heat of the sample in the range of 100-700℃ was tested by high-temperature differential scanning calorimeter, and the test results are shown in Figure 8 .

[0092] From Figure 8 , in the range of 100-640℃, the phase change material in the sample prepared in Example 3 has not yet undergone phase change, and the average specific heat at this time is 0.96 kJ / (kg·K); in the range of 640-665℃, the phase change material in the sample prepared in Example 3 is undergoing phase change; in the range of 665-700℃, the phase change of the phase change material in the sample prepared in Example 3 is complete, and the average specific heat at this time is 1.27 kJ / (kg·K). The energy storage density can be calculated by the following formula:

[0093]

[0094] where Q CPCM represents the energy storage density of the composite, m represents mass, T L and T H represent the initial and final temperature, respectively, C P represents the specific heat of the composite. The integral of the formula can be calculated to obtain the total energy storage density of up to 774.59 kJ / kg in the temperature range of 100-700℃.

[0095] 7. Photothermal conversion performance test

[0096] The photothermal conversion performance of the sample of Example 3 under different heat storage modes of flow state and static state was tested.

[0097] Test method: The temperature change of the particles was monitored by a thermocouple, and the temperature values were recorded by a data collector. The test results are shown in Figure 9 .

[0098] From Figure 9 , it can be obtained that, given the feeding and discharging speed of 0.58 g / s, the total incident energy flux reaches 1078.11 W. In the flow state heat storage process, the particles continuously absorb heat until the temperature rises to the melting point, and the required time is 284 s. After 322 s, the system reaches a stable state of 686℃, and the dynamic heating rate is 2.34℃ / s. Under the same experimental conditions, it takes 581 s to heat to the melting point in the static state, and the heating rate is 1.14℃ / s. The flow state heat storage response rate is significantly higher than that of the static heat storage.

[0099] The heat storage efficiency of the system is defined as:

[0100]

[0101] where Q CPCM represents the energy storage density of the composite, m represents mass, t represents the heating time, v represents the feeding and discharging speed, and Q light represents the total light flux. Through calculation, it can be obtained that, after reaching the steady state, the flow state heat storage system efficiency can reach 47.67%, while the system heat storage efficiency under the static stacking state is only 1.96%, which proves that the flow state heat storage mode can significantly enhance the heat storage efficiency of the particle photothermal conversion system.

Claims

1. A core-shell structured high-temperature photothermal phase change heat storage particle, characterized in that, It consists of a core material and a shell; the core material is white spherical particles with magnesium oxide and hexagonal boron nitride as the framework and sodium chloride-potassium chloride eutectic salt mounted on them; the shell is manganese iron black; by mass fraction, the content of the core material is 80~90% and the content of the shell is 10~20%; in the core material, by mass fraction, the content of magnesium oxide is 45~48%, the content of hexagonal boron nitride is 5~10%, and the content of sodium chloride-potassium chloride eutectic salt is 45~48%.

2. The core-shell structured high-temperature photothermal phase change thermal storage particle according to claim 1, characterized in that, In the core material, the particle size of the core-shell structure high-temperature photothermal phase change heat storage particles is 1~2 mm.

3. A method for preparing core-shell structured high-temperature photothermal phase change thermal storage particles as described in claim 1 or 2, characterized in that, Includes the following steps: (1) Place magnesium oxide, hexagonal boron nitride and sodium chloride-potassium chloride eutectic salt in a ball mill and mix them evenly. Add binder solution and stir thoroughly to make it a wet material. (2) The wet material is fed into the extruder and extruded into strips; (3) Disperse the strip mixture into segments, put them into a rounding machine to round them, collect the resulting particles, and dry them; (4) Add the particles to the binder solution, then add manganese iron black powder for coating until the manganese iron black powder is evenly coated on the surface of the particles to obtain black particles, and take them out. (5) The black particles are calcined to remove the binder, and the core-shell structure high-temperature photothermal phase change heat storage particles are obtained.

4. The method for preparing core-shell structured high-temperature photothermal phase change thermal storage particles according to claim 3, characterized in that, The adhesive is polyvinyl alcohol.

5. The method for preparing core-shell structured high-temperature photothermal phase change thermal storage particles according to claim 3, characterized in that, In step (5), the calcination temperature is 720~750°C and the time is 4~5 h.

6. The method for preparing core-shell structured high-temperature photothermal phase change thermal storage particles according to claim 3, characterized in that, In step (3), the drying temperature is 90~110°C and the drying time is 4~5 h.

7. The application of the core-shell structure high-temperature photothermal phase change thermal energy storage particles as described in claim 1 or 2 in the integration of photothermal conversion and phase change thermal energy storage.

8. The application according to claim 7, characterized in that, The core-shell structured high-temperature photothermal phase change thermal storage particles are in a fluid dynamic state during use.

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