External particle heat absorber and solar power generation system

Abstract

The present invention discloses an external particle heat absorber and solar power generation system. The system comprises a heat absorbing portion, the sun-facing end of which absorbs solar energy, and a particle heat exchanger disposed on the shady side of the heat absorbing portion. A heat pipe is also provided, with the evaporation end in heat transfer contact with the heat absorbing portion, and the condensation end in heat transfer contact with particles within the particle heat exchanger. A liquid phase-change medium within the evaporation end absorbs heat from the heat absorbing portion and evaporates into a gaseous phase-change medium. The phase-change medium then enters the condensation end, exchanges heat with cold particles within the particle heat exchanger, condenses into a liquid phase-change medium, and flows back to the evaporation end. The heated hot particles can then be output to the next external device through the output end of the particle heat exchanger. The heat absorbing portion absorbs solar energy, and the phase-change medium within the heat pipe serves as an intermediate heat exchange medium. After evaporation, the phase-change medium transfers heat to the particles, raising the particles to the desired temperature. This system exhibits high efficiency and addresses the low heat absorption efficiency of existing particle heat absorbers.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar thermal power generation, and in particular relates to an external particle heat absorber and a solar power generation system. Background Art

[0002] Solar energy is a green, sustainable, and clean energy source, potentially becoming an ideal primary energy source for the future. Solar thermal power generation, coupled with large-scale, affordable energy storage technology, offers smooth, stable, and dispatchable power output, promising broad application prospects.

[0003] Solid particle heat absorption and storage technology is a new type of solar heat absorption and storage technology and one of the mainstream technologies in the research of third-generation tower solar thermal power generation. Its main advantages are: solid particles can simultaneously meet the needs of heat absorption, heat transfer and heat storage; the cost of particles is relatively low; the heat absorption temperature of particles is high, reaching 1000°C; the storage and transportation of particles do not require the use of expensive metal materials, which reduces equipment costs.

[0004] Based on how solar energy heats the particles, particle absorbers can be divided into direct heating and indirect heating types. Particle heat exchange relies on thermal conductivity, so the heat exchange efficiency is relatively low, resulting in low thermal efficiency of conventional indirect heating absorbers. Therefore, the current mainstream technology uses solar energy to directly heat the particles. The most ideal structure for direct heating absorbers is the cavity absorber, but the particle flow rate is difficult to control, resulting in uneven temperature of the particles after heat absorption, affecting the use of the heat storage and exchange system. In addition, the cavity absorber has certain advantages in heat absorption efficiency, but the truncation efficiency is greatly reduced when the mirror field is expanded, resulting in no advantage in overall thermal efficiency. Therefore, the power station scale suitable for cavity absorbers is generally small.

[0005] Currently, molten salt solar thermal receivers are commonly externally mounted. Compared to cavity-type receivers, their overall thermal efficiency is less affected by the size of the solar field, making them suitable for larger solar thermal power plants and offering lower unit investment costs. Furthermore, external receivers are more convenient for circular solar field layouts, improving land utilization.

[0006] The existing cavity heat absorber has a heat absorption efficiency of 50% to 85%, a cutoff efficiency of only about 80%, and a comprehensive thermal efficiency of about 40% to 68%.

[0007] In summary, although particle heat absorption and storage technology has great application prospects, it needs to solve problems such as low comprehensive thermal efficiency of particles, stable control of particle heat absorption temperature and large-scale power station application. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide an external particle heat absorber and a solar power generation system to solve the problem of low heat absorption efficiency of the existing particle heat absorber.

[0009] In order to solve the above problems, the technical solution of the present invention is:

[0010] An external particle heat absorber of the present invention comprises a heat absorbing portion, a heat pipe and a particle heat exchanger;

[0011] The heat absorption part includes a sunny end and a shady end, and the particle heat exchanger is arranged on the shady end side;

[0012] The evaporation end of the heat pipe is in heat transfer contact with the heat absorption part; the condensation end of the heat pipe is in heat transfer contact with the particles in the particle heat exchanger;

[0013] The evaporation end is filled with a phase-change working medium, and the evaporation temperature of the phase-change working medium is higher than the temperature of the particles flowing in the particle heat exchanger.

[0014] The sun-facing end is an end of the heat absorbing part that receives sunlight, and the shady end is the other end of the heat absorbing part that is opposite to the sun-facing end.

[0015] In the external particle heat absorber of the present invention, the sun-facing end of the heat absorbing part is provided as a solid heat absorbing layer, and the shady end is provided as a heat conducting layer;

[0016] The evaporation end is in heat transfer contact with the heat conducting layer.

[0017] In the external particle heat absorber of the present invention, a single or multiple heat absorbing parts are arranged around the particle heat exchanger.

[0018] The external particle heat absorber of the present invention is provided with a plurality of first fins at the evaporation end.

[0019] The external particle heat absorber of the present invention is provided with a plurality of second fins at the condensation end.

[0020] The external particle heat absorber of the present invention, the heat pipe is a closed pulsating heat pipe.

[0021] The external particle heat absorber of the present invention is provided with a one-way valve on the heat pipe.

[0022] The external particle heat absorber of the present invention has at least two particle heat exchangers, and the shady end includes at least two heat exchange areas arranged transversely, with different particle heat exchangers corresponding to different heat exchange areas;

[0023] The particle output end of each particle heat exchanger is provided with a particle flow regulating valve.

[0024] In the external particle heat absorber of the present invention, the number of the particle heat exchangers is at least two, and different particle heat exchangers correspond to different heat absorbing parts;

[0025] The particle output end of each particle heat exchanger is provided with a particle flow regulating valve.

[0026] In the external particle heat absorber of the present invention, the phase change working medium is mercury and its alloys, sodium and its alloys, potassium and its alloys, cesium and its alloys, or sulfur and its compounds.

[0027] A solar power generation system of the present invention includes any one of the external particle heat absorbers described above.

[0028] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0029] 1. One embodiment of the present invention comprises a heat absorber, whose sunny end absorbs solar energy. A particle heat exchanger is positioned on the shady side of the heat absorber. A heat pipe is also provided, with the evaporator end in heat transfer contact with the heat absorber and the condenser end in heat transfer contact with the particles within the particle heat exchanger. The liquid phase-change medium in the evaporator end absorbs heat from the heat absorber and evaporates into a vapor phase-change medium. This phase-change medium then enters the condenser end, exchanges heat with the cold particles within the particle heat exchanger, and condenses into a liquid phase-change medium that flows back to the evaporator end. The heated particles are then output to the next external device through the output end of the particle heat exchanger. The heat absorber absorbs solar energy, and the phase-change medium in the heat pipe acts as an intermediate heat exchange medium. After evaporation, it transfers heat to the particles, raising the particles to the desired temperature, resulting in a high efficiency. In contrast, the heat absorption efficiency of a cavity-type heat absorber ranges from 50% to 85%, with a cutoff efficiency of only approximately 80%, and an overall thermal efficiency of approximately 40% to 68%. The entire heat absorption part of this embodiment can receive solar radiation, and the cutoff efficiency is as high as over 95%. The phase change working fluid in the heat pipe has extremely strong heat transfer capacity, and the particle heat exchange efficiency reaches 99%. Therefore, the comprehensive thermal efficiency is higher than that of the cavity heat absorber, which solves the problem of low heat absorption efficiency of the existing particle heat absorber.

[0030] 2. An embodiment of the present invention is an external heat absorber. Compared with a cavity heat absorber, it can adopt a circular mirror field layout, greatly improving land utilization and being more conducive to the construction of power stations with larger installed capacity.

[0031] 3. In one embodiment of the present invention, the individual particle heat exchangers are independent of each other and can be controlled differently according to solar radiation at different angles, which is beneficial for achieving uniform particle temperature.

[0032] 4. During a cold start, the molten salt heat sink requires electric heating to prevent freezing of the molten salt. Furthermore, the risk of freezing also exists when the DNI value is low, significantly reducing light resource utilization (approximately 85%). Electric heating also increases plant power consumption, reducing the amount of electricity available to the grid. However, in this embodiment, the phase-change fluid is in liquid form before startup. Neither the phase-change fluid nor the particles require preheating, enabling a cold start. Even at low DNI values, this can be achieved by reducing the particle flow rate, significantly increasing light resource utilization.

[0033] 5. In one embodiment of the present invention, the phase change working fluid adopts phase change driven circulation, which does not require an additional power source and does not require increased factory electricity.

[0034] 6. In one embodiment of the present invention, the closed pulsating heat pipe can transfer heat by utilizing only the latent heat of the working medium, and the temperature of the heat release section and the heat absorption section hardly changes, which greatly reduces the thermal shock and increases the service life of the closed pulsating heat pipe.

[0035] 7. In one embodiment of the present invention, fins are provided on both the evaporating tube and the condensing tube, which can achieve heat exchange with high heat flux density in a small area, and can quickly transfer the heat energy of the solid heat absorption layer to the particles, thereby reducing the size of the heat absorber and reducing the weight and cost of the equipment.

[0036] 8. In one embodiment of the present invention, the solid heat absorption layer utilizes a high-temperature-resistant non-metallic heat absorption material, such as magnesium oxide and corundum. These materials are inexpensive and highly resistant to thermal shock. This eliminates the need for high-strength alloys, significantly reducing the cost of the heat absorber. Furthermore, the heat absorption material itself possesses a certain heat storage capacity, providing a buffer for particle flow control during weather fluctuations, ensuring consistent particle temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a transverse cross-sectional view of the external particle heat absorber of the present invention;

[0038] Figure 2 is a schematic diagram of the external particle heat absorber of the present invention;

[0039] Figure 3 It is a vertical cross-sectional view of the external particle heat absorber of the present invention;

[0040] Figure 4 is a schematic diagram of another embodiment of the external particle heat absorber of the present invention;

[0041] Figure 5 Schematic diagram of another embodiment of the external particle heat absorber of the present invention.

[0042] Explanation of the reference numerals: 1: heat absorption part; 101: solid heat absorption layer; 102: heat conduction layer; 2: evaporation end; 3: first fin; 4: one-way valve; 5: condensation end; 6: second fin; 7: particle heat exchanger; 8: closed pulsating heat pipe; 9: particle flow regulating valve; 10: particle input end; 11: particle output end. DETAILED DESCRIPTION

[0043] The following is a detailed description of an external particle heat absorber and solar power generation system proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0044] Example 1

[0045] See Figures 1 to 3 In one embodiment, an external particle heat absorber includes a heat absorbing portion 1, a heat pipe, and a particle heat exchanger 7. The heat absorbing portion 1 includes a sun-facing end and a shade-facing end. The sun-facing end is used to receive solar radiation, and the opposite end is the shade-facing end, on one side of which the particle heat exchanger 7 is provided.

[0046] The evaporation end 2 of the heat pipe is in heat transfer contact with the heat absorption part, and the condensation end 5 of the heat pipe is in heat transfer contact with the particles in the particle heat exchanger 7. The evaporation end 2 is filled with a phase change working fluid, and the evaporation temperature of the phase change working fluid is higher than the heat absorption temperature of the particles flowing in the particle heat exchanger 7.

[0047] After the liquid phase change working medium in the evaporation end 2 absorbs the heat of the heat absorption part 1 and evaporates into the gas phase phase change working medium, it enters the condensation end 5 to exchange heat with the cold particles in the particle heat exchanger 7 and condenses into the liquid phase phase change working medium and flows back to the evaporation end 2, and the heated hot particles can be output to the next external device through the output end of the particle heat exchanger 7.

[0048] This embodiment uses a heat absorption portion 1 to absorb solar energy, and the phase change medium in the heat pipe serves as the intermediate heat exchange medium. After evaporation, it transfers heat to the particles and raises the particles to the desired temperature, achieving high efficiency. The heat absorption efficiency of a cavity-type heat absorber is between 50% and 85%, with a cutoff efficiency of only about 80%, and an overall thermal efficiency of approximately 40% to 68%. The entire heat absorption portion 1 of this embodiment can receive solar radiation, with a cutoff efficiency exceeding 95%. The phase change medium in the heat pipe has extremely strong heat transfer capabilities, and the particle heat exchange efficiency reaches 99%. Therefore, the overall thermal efficiency is higher than that of a cavity-type heat absorber, solving the problem of low heat absorption efficiency in existing particle heat absorbers.

[0049] The specific structure of the external particle heat absorber of this embodiment is further described below:

[0050] In this embodiment, the number of heat absorbing sections 1 can be one or more, each disposed around the particle heat exchanger 7. When there are multiple heat absorbing sections 1, the shady ends of the sections surround each other to form an inner annular surface. When there is only one heat absorbing section 1, the shape of the heat absorbing section 1 can be annular or polygonal, with space reserved for mounting the particle heat exchanger 7. This is not specifically limited here.

[0051] From the perspective of the number of particle heat exchangers 7: When there are at least two particle heat exchangers 7, the shady end of a single or multiple heat absorbing parts 1 can form an inner annular surface, which can be divided into at least two transversely arranged heat exchange areas. The number of these areas matches the number of particle heat exchangers 7, and different heat exchange areas correspond to different particle heat exchangers 7. At the same time, each particle heat exchanger 7 is equipped with a particle flow control valve 9, which is used to adjust the particle flow rate within the particle heat exchanger 7 in response to the different solar radiation intensities in different heat exchange areas, thereby controlling the heat exchange rate and ensuring the output temperature of the particles.

[0052] Because solar radiation energy varies in different directions, it is divided into different heat exchange zones. This stabilizes the particle temperatures within the different particle flow spaces corresponding to these zones, maintaining uniform particle temperature within each particle flow space. For example, if the horizontal cross-section of the solid heat absorption layer 101 is a hollow circular ring, the center of the circle can be equally divided into several heat exchange zones. If the horizontal cross-section is a hollow polygon, each side can be used to divide the shady end into several heat exchange zones.

[0053] In this embodiment, the heat absorption portion 1 comprises a solid heat absorption layer 101 and a heat conductive layer 102. The heat conductive layer 102 is attached to the surface of the solid heat absorption layer 101 facing away from the sun. The solid heat absorption layer 101 absorbs solar radiation, while the heat conductive layer 102 conducts it. The evaporation end 2 can be disposed through or attached to the heat conductive layer 102, thereby absorbing heat from the heat conductive layer 102 to heat the phase change medium.

[0054] Further, see Figure 4 and Figure 5 When there is only one heat absorbing portion, the horizontal cross-section of the solid heat absorbing layer 101 can be circular or polygonal. The specific design can be optimized based on actual needs and is not specifically limited here. The material of the solid heat absorbing layer 101 can be a high-temperature resistant non-metallic heat absorbing material, such as magnesium oxide or corundum, which is inexpensive and highly resistant to thermal shock. This eliminates the need for high-strength alloy materials, significantly reducing the cost of the heat absorber. Furthermore, the heat absorbing material itself has a certain heat storage capacity, providing a buffer time for particle flow control during weather fluctuations, ensuring particle temperature uniformity.

[0055] The material of the heat conducting layer 102 may be a material with high thermal conductivity, such as graphite or graphene.

[0056] See Figure 2 and Figure 3In this embodiment, the particle heat exchanger 7 may specifically include a particle input end 10 and a particle output end 11, an outer shell and an inner shell, and the outer shell is sleeved on the inner shell and cooperates to form a particle channel. The particle channel can be specifically arranged vertically to achieve gravity accumulation flow of the particles. The particle input end 10 is arranged at the top of the shell of the particle heat exchanger 7 and is connected to the top of the particle channel. The particle output end 11 is arranged at the bottom of the shell of the particle heat exchanger 7 and is connected to the bottom of the particle channel. Because the heat exchange method is that the condensation end 5 of the heat pipe extends into the particle channel for heat exchange, an inner shell will be arranged in the outer shell to form a particle channel to limit the width of the particle channel to ensure that the particles are fully heat exchanged.

[0057] Furthermore, a particle flow regulating valve 9 may be provided on the particle heat exchanger 7 , specifically installed at the particle output end 11 , for regulating the particle flow velocity in the particle channel.

[0058] In this embodiment, the heat pipes of the heat exchange module can be several closed pulsating heat pipes 8. These closed pulsating heat pipes 8 are arranged vertically in the corresponding heat exchange space, and each closed pulsating heat pipe 8 operates in a closed loop. The closed pulsating heat pipe 8 includes an evaporation section and a condensation section. The evaporation section passes through the solid heat absorption layer 101 or adheres to the inner wall of the solid heat absorption layer 101. The condensation section passes through the particle heat exchanger 7 or adheres to the outer wall of the particle heat exchanger 7, thereby exchanging heat with the particles.

[0059] Specifically, see Figure 1 and Figure 5 The evaporation section of the closed pulsating heat pipe 8 may include several evaporation tubes, and the condensation section may include several condensation tubes. The evaporation tubes and the condensation tubes are connected end to end in sequence. Both the evaporation tubes and the condensation tubes can be U-shaped tubes. After being connected to each other, a closed loop serpentine pipeline can be formed. Part of the evaporation tube receives heat at the solid heat absorption layer 101 to heat the phase change working medium; part of the condensation tube performs heat exchange and condensation at the particle channel, heating the particles and condensing the phase change working medium. Specifically, the evaporation tube can be partially passed through the heat conductive layer 102 or attached to the heat conductive layer 102; similarly, the condensation tube can be partially passed through the particle channel or attached to the outer wall of the particle channel.

[0060] Furthermore, a one-way valve 4 may be provided on the closed pulsating heat pipe 8 to ensure that the phase-change working medium in the pipe always maintains a one-way flow, thereby forming an internal circulation of the phase-change working medium.

[0061] Furthermore, the portion of the evaporator tube in contact with the solid heat absorption layer 101 may be provided with a plurality of first fins 3 to enhance the heat transfer rate between the solid heat absorption layer 101 and the evaporator tube. The portion of the condenser tube in contact with the particle passage may be provided with a plurality of second fins 6 to enhance the heat transfer rate between the condenser tube and the particle passage. Both the first fins 3 and the second fins 6 may be elongated or cross-shaped fins. The size, shape, and arrangement of the fins can be adjusted according to the specific heat exchange efficiency requirements and are not specifically limited here.

[0062] In this embodiment, the phase change working fluid may specifically include but is not limited to substances with an evaporation temperature exceeding 500°C under normal pressure, vacuum and high pressure conditions, such as mercury and its alloys, sodium and its alloys, potassium and its alloys, cesium and its alloys, sulfur and its compounds, carbon dioxide, water, etc.

[0063] The following describes the circulation process of the phase-change working medium within the external particle heat absorber of this embodiment. Because solar radiation energy varies in different directions, the heat exchange space is arranged in multiple directions to absorb solar energy from each direction. The heat absorption rate is regulated by the flow rate of the particle heat exchanger 7 corresponding to each direction. Solar energy is first absorbed by the solid heat-absorbing layer 101 and converted into thermal energy. This heat is then transferred to the evaporator tube of the closed pulsating heat pipe 8 through the thermal conductive layer 102. The liquid phase-change working medium within the evaporator tube absorbs the heat from the thermal conductive layer 102 and evaporates to form a high-pressure gas. This gas flows toward the condenser tube. After being cooled to a liquid state by the latent heat absorbed by the cold particles within the particle channel, the gas returns to the thermal conductive layer 102 and evaporates, completing the working medium circulation and heat transfer. Capillary and bending forces create an oscillating state within the tube, with randomly spaced gas and liquid plugs.

[0064] The following describes the operation of the particles in the external particle heat absorber of this embodiment: cold particles enter the particle channel from the particle input port 10 at the top of the particle heat exchanger 7, where they are heated by heat exchange with the second fins 6 and the condenser tube, causing the phase change medium to condense. The particle heat exchangers 7 are arranged in different heat exchange spaces along multiple directions, and the particle flow rate within each particle heat exchanger 7 can be individually adjusted. The advantage of this arrangement is that solar radiation energy is uneven at different angles, resulting in different heat exchange rates in the closed pulsating heat pipe 8. By arranging the particle heat exchangers 7 in multiple directions, the particle flow rate can be adjusted separately, controlling the heat exchange rate and ensuring the particle temperature at the particle output port 11.

[0065] The following is a specific description of the actual operation process of the external particle heat absorber of this embodiment:

[0066] The evaporation temperature of the phase-change working fluid in the closed pulsating heat pipe 8 is 800°C. When the solid heat absorption layer 101 receives solar radiation energy and heats up, the heat is quickly transferred to the evaporation tube through the internal heat-generating heat-conducting layer 102. The phase-change working fluid in the evaporation tube evaporates to produce bubbles, which rapidly expand and increase in pressure, driving the phase-change working fluid to move toward the condenser. The one-way valve 4 allows the working fluid to circulate in only one direction, ensuring the consistency of the working fluid flow direction. After flowing through the condenser, the working fluid bubbles are cooled and condensed into liquid by the cold particles. The liquid phase phase-change working fluid returns to the evaporation tube to reabsorb heat, completing the entire working fluid cycle and transferring heat to the particles. After absorbing the latent heat of the working fluid, the particles heat up to 700°C and enter the subsequent hot particle storage tank for storage.

[0067] When the solar radiation DNI value increases, the amount of bubbles in the heat pipe increases, the pressure difference between the evaporator and the condenser increases, and the working medium circulation speed increases. By increasing the particle flow rate, the condensation speed of the gas phase change working medium is adjusted to maintain the pressure difference in the closed pulsating heat pipe 8. When the solar radiation DNI value decreases, the heat stored in the solid heat absorption layer 101 within a certain period of time can still maintain the amount of bubbles generated in the evaporator. However, when the solar radiation DNI value continues to decrease, the amount of bubbles in the evaporator gradually decreases, the pressure difference between the evaporator and the condenser decreases, and the working medium circulation speed decreases. By reducing the particle flow rate, the condensation speed of the gas phase working medium is adjusted to maintain the pressure difference in the closed pulsating heat pipe 8. The particle heat exchanger 7 adopts a modular design, and the particle flow rate in the particle heat exchanger 7 is adjusted according to the pressure difference of the closed pulsating heat pipe 8 in each heat exchange space to maintain the uniformity of the particle temperature at the outlet of the particle heat exchanger 7.

[0068] When the solar radiation DNI changes, the temperature of the evaporator and condenser tubes always remains at around 800°C, the thermal shock of the heat pipes is small, and the life of the equipment is greatly extended.

[0069] Example 2

[0070] A solar power generation system includes the external particle heat absorber of the above-mentioned embodiment 1. A heat absorption part 1 is used to absorb solar energy, and the phase change medium in the heat pipe is used as the intermediate heat exchange medium. After evaporation, the heat is transferred to the particles and the particles are raised to the required temperature, which has a higher efficiency. The heat absorption efficiency of the cavity heat absorber is between 50% and 85%, the cutoff efficiency is only about 80%, and the comprehensive thermal efficiency is about 40% to 68%. The heat absorption part 1 of this embodiment can be exposed to solar radiation as a whole, and the cutoff efficiency is as high as over 95%. The phase change medium in the heat pipe has a very strong heat transfer capacity, and the particle heat exchange efficiency reaches 99%. Therefore, the comprehensive thermal efficiency is higher than that of the cavity heat absorber, which solves the problem of low heat absorption efficiency of the existing particle heat absorber.

[0071] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the scope of protection of the present invention.

Claims

1. An external particle heat absorber, characterized in that: It includes a heat absorbing part (1), a heat pipe and a particle heat exchanger (7); The heat absorption part (1) comprises a sun-facing end and a shady end, and the particle heat exchanger (7) is arranged on the shady end side; The evaporation end (2) of the heat pipe is in heat transfer contact with the heat absorption part (1); the condensation end (5) of the heat pipe is in heat transfer contact with the particles in the particle heat exchanger (7); The evaporation end (2) is filled with a phase-change medium, and the evaporation temperature of the phase-change medium is higher than the temperature of the particles flowing in the particle heat exchanger (7); the phase-change medium in the liquid phase in the evaporation end (2) absorbs the heat of the heat absorption part (1) and evaporates into a gas phase phase-change medium, then enters the condensation end (5) to exchange heat with the cold particles in the particle heat exchanger (7) and condenses into a liquid phase phase-change medium and flows back to the evaporation end (2); The sun-facing end of the heat-absorbing portion (1) is provided as a solid heat-absorbing layer (101), and the sun-facing end is provided as a heat-conducting layer (102); The evaporation end (2) is in heat transfer contact with the heat conducting layer (102); A single or multiple heat absorption parts (1) are arranged around the particle heat exchanger (7).

2. The external particle heat absorber according to claim 1, characterized in that: The evaporation end is provided with a plurality of first fins (3).

3. The external particle heat absorber according to claim 1, characterized in that: The condensation end is provided with a plurality of second fins (6).

4. The external particle heat absorber according to claim 1, characterized in that: The heat pipe is a closed pulsating heat pipe (8).

5. The external particle heat absorber according to claim 1, characterized in that: A one-way valve (4) is provided on the heat pipe.

6. The external particle heat absorber according to claim 1, characterized in that: The number of the particle heat exchangers (7) is at least two, the shady end comprises at least two heat exchange areas arranged transversely, and different particle heat exchangers (7) correspond to different heat exchange areas; The particle output end of each particle heat exchanger (7) is provided with a particle flow regulating valve (9).

7. The external particle heat absorber according to claim 1, characterized in that: The number of the particle heat exchangers (7) is at least two, and different particle heat exchangers (7) correspond to different heat absorbing parts (1); The particle output end of each particle heat exchanger (7) is provided with a particle flow regulating valve (9).

8. The external particle heat absorber according to claim 1, characterized in that: The phase change working medium is mercury and its alloys, sodium and its alloys, potassium and its alloys, cesium and its alloys, or sulfur and its compounds.

9. A solar power generation system, characterized in that: It comprises the external particle heat absorber as described in any one of claims 1 to 8.

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