A particle heat absorber and solar power generation system

Abstract

The present invention discloses a particle heat absorber and solar power generation system. The system comprises a heat absorbing portion disposed within a heat absorption region and a heat exchange portion disposed within a heat exchange region. The heat absorbing portion extends into the heat exchange region and engages with the heat exchange portion, and the heat absorbing portion is filled with a heat absorbing fluid. The heat exchange region is located within a housing, meaning that the heat exchange process of the particles occurs within the housing. This reduces heat loss and improves the heat absorption efficiency of the particles, resolving the low efficiency issue 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 a 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 heat conduction, so the heat exchange efficiency is relatively low, resulting in low thermal efficiency of conventional indirect heating absorbers. Therefore, the existing mainstream technology is to use solar energy to directly heat the particles. The most ideal structure for direct heating absorbers is an open cavity absorber, but the particle flow rate is difficult to control, resulting in uneven particle temperature after heat absorption, severe heat loss, and low absorber efficiency. The higher the particle temperature, the lower the efficiency of the particle absorber, which greatly limits the application of particle energy storage technology in the field of solar thermal power generation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a particle heat absorber and a solar power generation system to solve the problem of low efficiency of existing particle heat absorbers.

[0006] In order to solve the above problems, the technical solution of the present invention is:

[0007] A particle heat absorber of the present invention comprises a heat absorbing portion, a heat exchanging region and a heat exchanging portion;

[0008] The heat exchange part is arranged in the heat exchange area, and the particles are in heat transfer contact with the heat exchange part in the heat exchange area; a shell is arranged outside the heat exchange area;

[0009] The heat absorbing part is filled with a heat absorbing fluid, and the lower end of the heat absorbing part extends into the heat exchange area and is in heat transfer contact with the heat exchange part.

[0010] In the particle heat absorber of the present invention, the heat exchange portion includes a heat pipe and / or a heat exchange pipeline.

[0011] In the particle heat absorber of the present invention, the heat exchange pipeline is connected to the interior of the heat absorption part to form a circulation pipeline, and the circulation pipeline is provided with a driving pump; one end of the heat pipe is in heat transfer contact with the heat absorption part.

[0012] In the particle heat absorber of the present invention, the plurality of heat pipes are spaced apart and arranged in a staggered manner.

[0013] In the particle heat absorber of the present invention, the heat exchange pipeline includes a plurality of heat exchange pipe networks; the heat exchange pipe networks are arranged at intervals in the height direction and form the circulation pipelines with the heat absorption parts respectively.

[0014] In the particle heat absorber of the present invention, the heat absorbing part is a heat absorbing tube arranged in a ring shape on the shell.

[0015] The particle heat absorber of the present invention further includes a particle conveying portion, and the output end of the particle conveying portion extends into the heat exchange area.

[0016] The particle heat absorber of the present invention further includes a particle heat exchanger, and the input end of the particle heat exchanger is arranged below the heat exchange area.

[0017] The particle heat absorber of the present invention further comprises a hot particle collecting portion and a cold particle collecting portion;

[0018] The hot particle collecting portion is provided between the heat exchange region and the input end of the particle heat exchanger;

[0019] The cold particle collecting portion is provided between the output end of the particle heat exchanger and the input end of the particle conveying portion.

[0020] In the particle heat absorber of the present invention, the heat absorbing fluid is liquid metal.

[0021] In the particle heat absorber of the present invention, the driving pump is a high-temperature pump.

[0022] A solar power generation system of the present invention includes any one of the above-mentioned particle heat absorbers.

[0023] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0024] 1. One embodiment of the present invention incorporates a heat absorbing portion within a heat exchange region. The heat absorbing portion extends into the heat exchange region and engages with the heat exchange portion. The heat absorbing portion is filled with a heat absorbing fluid. The heat exchange region is located within the housing, meaning the particles exchange heat within the housing. This reduces heat loss and improves the particle absorption efficiency, resolving the low efficiency issue of existing particle heat absorbers.

[0025] 2. One embodiment of the present invention connects a heat exchange pipeline to the interior of the heat absorption section, forming a circulation pipeline. A heat-absorbing fluid is driven by a drive pump to flow within the circulation pipeline. This separates the traditional cavity-type particle heat absorber into two processes: heat absorption by the heat-absorbing fluid and heat exchange between the heat-absorbing fluid and the particles. The heat-absorbing fluid flows within the heat absorption section, absorbs heat, and is driven by the drive pump to the heat exchange pipeline located in the heat exchange area, where it exchanges heat with the particles. The heat-absorbing fluid flows only within the heat absorption section and the heat exchange pipeline, avoiding direct contact with the outside world. This further improves the heat absorption efficiency of the particles during the heat absorption process.

[0026] 3. In one embodiment of the present invention, a plurality of heat pipes are further provided in the heat exchange area in heat transfer contact with the heat absorption part, so that the particles can exchange heat twice with the heat pipes and the heat exchange pipeline respectively in the heat exchange area, thereby increasing the heat exchange area and improving the heat exchange efficiency of the particles.

[0027] 4. In one embodiment of the present invention, a heat absorption tube is provided above the shell, and the liquid metal in the heat absorption tube absorbs heat, so that the mirror field can adopt a more efficient circular mirror field layout rather than the inefficient fan-shaped mirror field with a cavity-type particle heat absorber, further improving the photothermal efficiency.

[0028] 5. One embodiment of the present invention applies liquid metal to the heat absorption and heat exchange process with particles. Since the heat absorption part and the heat exchange area are in close contact, the amount of expensive liquid metal can be reduced, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of a particle heat absorber of the present invention;

[0030] Figure 2 Schematic diagram of the heat absorption inlet and heat absorption outlet of the particle heat absorber of the present invention;

[0031] Figure 3 Schematic diagram of the heat exchange inlet and heat exchange outlet of the particle heat absorber of the present invention;

[0032] Figure 4 Schematic diagram of the expansion of the heat absorption tube of the particle heat absorber of the present invention

[0033] Explanation of the accompanying symbols: 1: heat absorption part; 2: elevator; 3: heat pipe; 4: driving pump; 5: heat exchange network; 6: mixer; 7: hot particle tank; 8: particle heat exchanger; 9: cold particle tank; 10: screener; 11: stacking silo; 12: elevator bucket; 13: heat absorption outlet; 14: heat exchange inlet; 15: heat exchange outlet; 16: heat absorption inlet. DETAILED DESCRIPTION

[0034] The particle heat absorber and solar power generation system proposed by the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0035] Example 1

[0036] See Figure 1 In one embodiment, a particle heat absorber includes a heat absorption area, a heat exchange area, a heat absorption part 1, a heat exchange part and a driving pump 4.

[0037] A shell is provided outside the heat exchange area to prevent the heat exchange area from contacting the outside world and reduce heat loss. The heat absorption area is located above the heat exchange area.

[0038] The heat absorption unit 1 is located within the heat absorption region and is used to absorb solar radiation from the mirror field. The heat exchange unit is located within the heat exchange region. The output end of the heat absorption unit 1 extends into the heat exchange region and is in heat transfer contact with the input end of the heat exchange unit. The heat absorption unit 1 is filled with a heat absorbing fluid.

[0039] This embodiment provides a heat absorbing portion 1 within the heat absorbing region and a heat exchanging portion within the heat exchanging region. The heat absorbing portion 1 extends into the heat exchanging region, where it is in heat transfer contact with the heat exchanging portion. Heat absorbing portion 1 is filled with a heat absorbing fluid. The heat exchanging region is located within the housing, meaning the particles exchange heat within the housing. This minimizes heat loss and significantly improves the particle absorption efficiency, resolving the low efficiency issue of existing particle heat absorbers.

[0040] The specific structure of the particle heat absorber of this embodiment is further described below:

[0041] In this embodiment, the heat absorption unit 1 can be a heat absorption tube arranged in an annular shape on the housing. A heat absorption fluid flows within the heat absorption tube, absorbing solar energy from the surrounding mirror field. The heat absorption tube can be mounted directly on the housing, with its lower end partially extending into the housing to facilitate connection with the heat exchange unit.

[0042] The heat-absorbing fluid is liquid metal, and the evaporation point of the liquid metal is at least 200°C higher than the temperature of the particles in the heat exchange area, so as to avoid phase change, pressure increase and tube burst when the liquid metal is overheated.

[0043] In this embodiment, the heat exchange unit 1 may specifically include a heat pipe and / or a heat exchange pipeline. Specifically, it may include both a heat pipe and a heat exchange pipeline. One end of the heat pipe 3 is in heat transfer contact with the heat absorption unit 1; the heat exchange pipeline is connected to the lower end of the heat absorption pipe, forming a circulation pipeline. A drive pump 4 is provided in the circulation pipeline to drive the heat absorption fluid in the heat absorption unit 1 from the heat absorption unit 1 into the heat exchange pipeline.

[0044] See Figure 2 and Figure 3The heat exchange pipelines can specifically be a plurality of heat exchange pipe networks 5. The heat exchange pipe networks 5 are spaced apart in the heat exchange region in the height direction, that is, sequentially arranged in the heat exchange region along the direction of particle flow, thereby forming a multi-layer structure. The heat exchange pipe networks 5 are provided with a plurality of particle channels for particles to pass through. The particles fall through the particle channels under the action of gravity and exchange heat with the heat exchange pipes during the falling process. In terms of connection, the heat absorption pipe is provided with a heat absorption inlet 16 and a heat absorption outlet 13, and the heat exchange pipe network 5 is provided with a heat exchange inlet 14 and a heat exchange outlet 15. The heat absorption outlet 13 is connected to the heat exchange inlet 14 by a connecting pipe, and the heat exchange outlet 15 is connected to the heat absorption inlet 16 by a connecting pipe. In terms of layout, the pipelines of several heat exchange pipe networks 5 can be connected in sequence, and the heat exchange pipe networks 5 at both ends are connected to the input end and output end of the heat absorption pipe of the heat absorption part 1 through connecting pipes to form a circulation pipeline; or both ends of each heat exchange pipe network 5 can be connected to the input end and output end of the heat absorption pipe through connecting pipes, thereby forming multiple circulation pipelines, which is not specifically limited here.

[0045] By setting up a heat exchange network 5 connected to the interior of the heat absorption part, a circulation pipeline is formed. The heat absorption fluid is driven by the drive pump 4 to flow in the circulation pipeline. The traditional cavity-type particle heat absorber is divided into the process of heat absorption by the heat absorption fluid and heat exchange between the heat absorption fluid and the particles. The heat absorption fluid flows in the heat absorption part 1, absorbs heat, and is driven by the drive pump 4 to the heat exchange network 5 located in the heat exchange area, where it exchanges heat with the particles. The heat absorption fluid flows only within the heat absorption part 1 and the heat exchange network 5, without direct contact with the outside world, further improving the heat absorption efficiency of the particles during the heat absorption process.

[0046] In this embodiment, see Figure 4 The number of heat pipes 3 can be multiple, and the heat pipes 3 are arranged in an intermittent and staggered manner within the heat exchange region, with one end of the heat pipe 3 being heat-transferably connected to the wall surface of the heat absorbing pipe. Preferably, because the outer ring of the heat absorbing pipe is used for heat absorption, and the inner ring can be connected to the heat pipe 3 for heat transfer, the lower end of the heat absorbing pipe can be extended into the shell, so that the heat pipe 3 in the heat absorption region can be directly arranged at the lower end of the inner ring of the heat absorbing pipe. The heat pipes 3 can be arranged in a plurality of rows in the horizontal direction, and the heat pipes 3 in adjacent rows are staggered. This allows the heat pipes 3 to have a certain barrier effect on passing particles, thereby achieving the purpose of increasing heat exchange.

[0047] By further arranging a plurality of heat pipes 3 in heat transfer connection with the heat absorption part 1 in the heat exchange area, the particles can exchange heat twice with the heat pipes 3 and the heat exchange network 5 in the heat exchange area, thereby increasing the heat exchange area and improving the heat exchange efficiency of the particles.

[0048] In this embodiment, the particle heat absorber further includes a hot particle collecting portion, a particle heat exchanger 8 , a cold particle collecting portion and a particle conveying portion.

[0049] The input end of the hot particle collection unit is connected to the output end of the housing, and is used to receive and store the hot particles that have undergone heat exchange in the housing. The input end of the particle heat exchanger 8 is connected to the output end of the hot particle collection unit, and is used to receive the hot particles and exchange heat with the power generation working medium.

[0050] The input end of the cold particle collection section is connected to the output end of the particle heat exchanger 8. The output end of the cold particle collection section is connected to the input end of the particle conveying section. The output end of the particle conveying section extends into the heat exchange area within the housing, and is used to convey the particles in the cold particle collection section after heat exchange to the heat exchange area within the housing for further heat exchange, thereby achieving recycling of the particles.

[0051] The hot particle collection unit includes a mixer 6 and a hot particle tank 7. The input end of the mixer 6 is connected to the output end of the housing, and the output end of the mixer 6 is connected to the input end of the hot particle tank 7. The mixer 6 is used to mix the hot particles after heat exchange in the heat exchange area to achieve a uniform temperature and output them to the hot particle tank 7 for storage. The output end of the hot particle tank 7 is connected to a particle heat exchanger 8. After the particle heat exchanger 8 receives the hot particles from the hot particle tank 7, the hot particles exchange heat with the power generation working fluid within the particle heat exchanger 8 and become cold particles.

[0052] The cold pellet collection unit includes a cold pellet tank 9, a screener 10, and a storage bin 11. The input of the cold pellet tank 9 is connected to the output of the pellet heat exchanger 8, storing the cold pellets. The output of the cold pellet tank 9 is connected to the input of the screener 10, which in turn is connected to the input of the storage bin 11. The screener 10 screens the cold pellets and delivers them to the storage bin 11 for storage. The output of the storage bin 11 is connected to the input of the pellet conveyor.

[0053] The conveying unit can be an elevator 2. Because the housing, hot particle collection unit, particle heat exchanger 8, and cold particle collection unit are arranged sequentially from top to bottom, the elevator 2 is required to drive the lifting bucket 12 to lift the cold particles from the cold particle collection unit below to the housing above and output them into the heat exchange area. Furthermore, a particle sprayer can be installed above the elevator 2 to evenly spray the particles into the heat exchange area, thereby improving the efficiency of the particle heat exchange.

[0054] In this embodiment, the driving pump 4 can be a high-temperature pump, which can be specifically arranged on the connecting pipeline between the heat absorption tube and the heat exchange network 5 to drive the liquid metal to absorb solar energy from the heat absorption tube and flow into the heat exchange network 5 to avoid damage to the structure of the heat absorption tube and the heat exchange network 5.

[0055] Example 2

[0056] A solar power generation system includes the particle heat absorber of the above-mentioned embodiment 1. By setting a heat absorption part 1 in the heat absorption area and a heat exchange part in the heat exchange area, the heat exchange part and the heat absorption part 1 are connected through a pipeline to form a circulation pipeline filled with a heat absorption fluid. The traditional cavity-type particle heat absorber is divided into the process of heat absorption by the heat absorption fluid and heat exchange between the heat absorption fluid and the particles. The heat absorption fluid flows in the heat absorption part 1 to absorb heat and is driven by the drive pump 4 to the heat exchange part, and exchanges heat with the particles in the heat exchange part. The heat absorption fluid only flows inside the heat absorption part 1 and the heat exchange part and does not directly contact the outside world. At the same time, the heat exchange area is located in the shell, that is, the heat exchange process of the particles is in the shell, and the heat loss is small, which can improve the heat absorption efficiency of the particle heat absorption process, and solve the problem of low efficiency of the existing particle heat absorber.

[0057] 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. A particle heat absorber, characterized in that: It includes a heat absorbing portion (1), a heat exchange region and a heat exchange portion; The heat exchange part is arranged in the heat exchange area, and the particles are in heat transfer contact with the heat exchange part in the heat exchange area; a shell is arranged outside the heat exchange area; The heat absorbing part (1) is filled with a heat absorbing fluid, and the lower end of the heat absorbing part (1) extends into the heat exchange area and is in heat transfer contact with the heat exchange part; The heat exchange part comprises a heat pipe (3) and a heat exchange pipeline; The heat exchange pipeline is connected to the interior of the heat absorption part (1) to form a circulation pipeline, and the circulation pipeline is provided with a driving pump (4); one end of the heat pipe (3) is in heat transfer contact with the heat absorption part (1).

2. The particle heat absorber according to claim 1, characterized in that The heat pipes are arranged at intervals and in a staggered manner.

3. The particle heat absorber according to claim 1, characterized in that The heat exchange pipeline comprises a plurality of heat exchange pipe networks (5); the heat exchange pipe networks (5) are arranged at intervals in the height direction and respectively form the circulation pipeline with the heat absorption part (1).

4. The particle heat absorber according to claim 1, characterized in that The heat absorbing part (1) is a heat absorbing tube arranged in a ring shape.

5. The particle heat absorber according to claim 1, characterized in that The heat absorbing fluid is liquid metal.

6. A solar power generation system, characterized in that: The device comprises a particle heat absorber as described in any one of claims 1 to 5.

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