A particle heat absorber and solar power generation system

Abstract

The present invention discloses a particle heat absorber and solar power generation system, wherein a heat exchange part is arranged in a shell, and a gap formed between the heat exchange part and the shell is arranged as a cold particle storage space for storing cold particles to be exchanged; a heat absorption part is arranged at the same time for absorbing solar energy and in heat transfer contact with the heat exchange part to heat the particles in the heat exchange part. This arrangement combines the cold particle storage tank and the heat absorber into one, and uses the cold particle storage space as the cold particle storage tank, which not only saves the cold particle storage tank and the cold particle buffer tank, but also simplifies the system structure, saves system space, and greatly reduces system cost.

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, and therefore may become an ideal main energy source in the future. Solar thermal power generation has a wide range of application prospects because it is equipped with large-scale and cheap energy storage technology, so the power output is smooth, stable and dispatchable.

[0003] Solid particle heat absorption and storage technology is a new type of solar energy 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 meet the needs of heat absorption, heat transfer and heat storage at the same time; the cost of particles is low; the particle absorption temperature is high, up to 1000°C, which greatly improves the hot spot efficiency at the back end of the solar thermal power plant; the storage and transportation of particles does not require the use of expensive metal materials, reducing equipment costs.

[0004] According to the way solar energy heats the particles, particle absorbers can be divided into direct heating and indirect heating. Particle heat exchange depends on heat conduction, so the heat exchange efficiency is 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 a direct heating absorber is a cavity absorber, but the particle flow rate is difficult to control, resulting in uneven temperature of the particles after heat absorption, affecting the performance of the heat storage and exchange system. Existing particle absorbers all have disadvantages such as complex systems, large equipment space, and low heat absorption efficiency. As key equipment that needs to be built on the top of a two-hundred-meter-high heat absorption tower, these shortcomings will greatly increase the system cost and significantly reduce the reliability of the system. 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 that the existing particle heat absorber occupies a large space and has a complex system.

[0006] To solve the above problems, the technical solution of the present invention is:

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

[0008] The heat absorbing part is in heat transfer contact with the heat exchanging part;

[0009] The heat exchange part is arranged in the shell and forms a cold particle storage space between the heat exchange part and the shell.

[0010] The particle heat absorber of the present invention, the heat exchange part includes a heat pipe and a heat exchange cavity; a heat exchange space is provided between the heat pipe and the heat exchange cavity;

[0011] The heat exchange cavity comprises a particle distribution area and a particle heat exchange area, wherein the particle distribution area is arranged at one end of the shell adjacent to the heat absorption part, one end of the particle heat exchange area is connected to the particle distribution area, and the other end is connected to the particle collector outside the shell;

[0012] The evaporation end of the heat pipe is in heat transfer contact with the heat absorption part, and the condensation end is arranged in the particle heat exchange area.

[0013] In the particle heat absorber of the present invention, the heat exchange cavity comprises at least two particle heat exchange zones.

[0014] In the particle heat absorber of the present invention, the heat absorbing part is arranged on one side of the shell, and the heat absorbing part is a radiation absorbing plate.

[0015] In the particle heat absorber of the present invention, the heat pipe is filled with liquid metal, the melting point of the liquid metal is lower than the lowest temperature of the particles in the heat exchange cavity, and the evaporation point is higher than the temperature of the particles in the particle heat exchange area.

[0016] The particle heat absorber of the present invention also includes a particle fluidization section, the input end of the particle fluidization section is connected to the cold particle storage space, and the output end of the particle fluidization section is connected to the particle distribution area, which is used to fluidize the particles and output them into the heat exchange section.

[0017] The particle fluidization section includes a particle fluidizer and an air compressor; the output end of the air compressor is connected to the particle fluidizer; the input end of the particle fluidizer is connected to the cold particle storage space, and the output end of the particle fluidizer is connected to the input end of the particle distribution area.

[0018] The particle heat absorber of the present invention further comprises a cyclone separator and an exhaust duct;

[0019] the input end of the cyclone separator is connected to the particle collector;

[0020] The cyclone separator further comprises a first output end for discharging particles and a second output end for discharging gas; the second output end is in communication with the cold particle storage space through the exhaust duct.

[0021] In the particle heat absorber of the present invention, a particle fluidization pipeline is arranged between the output end of the particle fluidization part and the particle distribution area, and the particle fluidization pipeline is provided with a check valve.

[0022] The particle heat absorber of the present invention is provided with a particle input end and a particle output end on the shell which are connected with the cold particle storage space.

[0023] A solar power generation system of the present invention comprises any one of the particle heat absorbers described above.

[0024] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0025] 1. In one embodiment of the present invention, the heat exchange part is arranged in the shell, and the gap formed between the heat exchange part and the shell is set as a cold particle storage space for storing the cold particles to be exchanged; at the same time, a heat absorption part is arranged to absorb solar energy and make heat transfer contact with the heat exchange part to heat the particles in the heat exchange part. This arrangement combines the cold particle storage tank and the heat absorber into one, and uses the cold particle storage space as the cold particle storage tank, eliminating the cold particle storage tank and the cold particle buffer tank, streamlining the system structure, saving system space, and greatly reducing system costs.

[0026] 2. In one embodiment of the present invention, the radiation absorption plate is directly arranged on the shell, so that the heat pipe is completely in the heat exchange cavity, there is no cavity opening, the heat loss is very small, and it is not affected by external environmental conditions.

[0027] 3. An embodiment of the present invention fluidizes cold particles through a particle fluidization section, and outputs the particles in a fluidized state to a heat exchange section, so that the fluidized particles exchange heat with the heat pipe in the heat exchange space, thereby overcoming the disadvantage of poor thermal conductivity of the particles and improving the efficiency of the heat absorber. The particle flow rate and flow velocity can be controlled through the particle fluidization section, thereby improving the stability of the system and solving the problem of low heat absorption efficiency of existing particle heat absorbers.

[0028] 4. In one embodiment of the present invention, the low-temperature particles in the cold particle storage space are in a static state, and the heat transfer coefficient between them and the heat exchange tube is very low, which effectively plays the role of the insulation layer. At the same time, a small part of the energy dissipated from the heat exchange tube is also absorbed by the low-temperature particles and finally used for power generation, which significantly improves the energy utilization rate and saves the material consumption of the insulation layer of the particle heat absorber, which not only reduces the size of the heat absorber, but also saves the cost of insulation materials.

[0029] 5. In one embodiment of the present invention, a cyclone separator is provided to separate hot particles and hot air, and the hot air is introduced into the cold particle storage space through an exhaust duct, where the cold particles in the cold particle storage space absorb and utilize the heat of the hot air, thereby reducing the heat loss of the system and improving the utilization rate of thermal energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of a particle heat absorber of the present invention;

[0031] Figure 2 is a schematic diagram of a heat exchange portion of a particle heat absorber of the present invention;

[0032] Figure 3 Another schematic diagram of the heat exchange portion of the particle heat absorber of the present invention.

[0033] Explanation of the reference numerals: 1: particle input end; 2: shell; 3: heat pipe; 4: radiation absorption plate; 5: particle distribution area; 6: check valve; 7: particle fluidizer; 8: air distribution plate; 9: flow control valve; 10: air compressor; 11: cyclone separator; 12: particle collector; 13: exhaust duct; 14: cold particle storage space; 15: heat exchange space; 16: particle fluidization duct; 17: particle output end; 18: heat exchange tube. DETAILED DESCRIPTION

[0034] The particle heat absorber and solar power generation system proposed by the present invention are further described in detail below 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.

[0035] Embodiment 1

[0036] See also Figures 1 to 3 In one embodiment, a particle heat absorber includes a shell 2, a heat absorbing part, and a heat exchanging part.

[0037] The heat absorption part is used to receive the radiation energy of the mirror field and to be in heat transfer contact with the particles in the heat exchange part.

[0038] The heat exchange part is arranged in the shell 2 and forms a cold particle storage space 14 between the shell 2;

[0039] The shell 2 is provided with a particle input end 1 and a particle output end 17 which are connected to the cold particle storage space 14 . The particle input end 1 is used to receive external cold particles, and the particle output end 17 is used to output particles into the heat exchange part.

[0040] In this embodiment, the heat exchange part is arranged in the shell 2, and the gap formed by the heat exchange part and the shell 2 is used as the cold particle storage space 14, the cold particle storage tank and the heat absorber are integrated into one, and the space outside the heat exchange part is used as the cold particle storage tank, which not only eliminates the cold particle storage tank and the cold particle buffer tank, but also simplifies the system structure, saves system space, and greatly reduces system costs.

[0041] The specific structure of the particle heat absorber of this embodiment is further described below:

[0042] See also Figure 2 and Figure 3 In this embodiment, the heat absorbing part is a radiation absorbing plate 4, which is made of a high temperature resistant material with a high absorption rate. It directly receives the radiation energy from the mirror field and transfers the energy to the heat exchange part connected thereto.

[0043] In this embodiment, the heat exchange part includes a plurality of heat pipes 3 and a heat exchange cavity, and a heat exchange space 15 is provided between the heat pipes and the heat exchange cavity. The heat exchange cavity includes a connected particle distribution area 5 and a particle heat exchange area, and the heat exchange cavity can be directly arranged in the shell 2 and cooperate with the inner wall surface of the shell 2 to form the particle distribution area 5, that is, the particle distribution area 5 is arranged at one end of the shell 2 close to the heat absorption part, the input end of the particle heat exchange area is connected to the particle distribution area 5, and the output end is connected to the particle collector 12 outside the shell.

[0044] The heat exchange cavity may specifically include a housing and a plurality of heat exchange tubes 18. The housing may specifically be a rectangular hollow shell 2, and the inner cavity is a particle distribution area 5. Further, the outer side of the shell 2 may be replaced with a radiation absorption plate 4, and the housing may be directly integrated with the radiation absorption plate 4, and the particle distribution area 5 is formed by the radiation absorption plate 4 and the housing.

[0045] The input end of each heat exchange tube 18 is respectively connected to the surface of the housing shell away from the heat absorption part and communicated with the particle distribution area 5, and the output end is communicated with the particle collector 12. The hollow inner cavity of the heat exchange tube 18 is the above-mentioned particle heat exchange area, and the number of heat pipes 3 matches the number of heat exchange tubes 18. At this time, the evaporation end of the heat pipe 3 can be directly connected to the radiation absorption plate 4 in the particle distribution area 5 to receive the heat of the radiation absorption plate 4, and the condensation end extends into the corresponding heat exchange tube 18 to form a heat exchange space 15. The particles flow in the heat exchange space 15 and exchange heat with the heat pipe 3.

[0046] The heat pipe 3 contains liquid metal whose melting point is at least 50°C lower than the lowest temperature of the particles in the heat exchange cavity and whose evaporation point is at least 200°C higher than the temperature of the particles in the particle heat exchange zone, and is used to quickly take away the heat of the radiation absorption plate 4 and transfer it to the fluidized particles.

[0047] In this embodiment, the particle heat absorber may further include a particle fluidizing section. The output end of the particle fluidizing section is connected to the input end of the accommodating shell, and is used to fluidize the particles and output them to the particle distribution area 5 and the heat exchange space 15 (fluidization is a phenomenon in which solid particles exhibit a fluid-like state under the action of a fluid). The output end of the heat exchange tube 18 is connected to the particle collecting section, and is used to collect the hot particles in the heat exchange space 15 after heat exchange.

[0048] Furthermore, the output end of the particle collector may be further provided with a cyclone separator 11 and an exhaust duct 13. The particle collector 12 may be specifically a rectangular parallelepiped housing 2, the input end of which is connected to the output end of the heat exchange pipe 18, and the output end of the particle collector 12 is connected to the input end of the cyclone separator 11, so as to collect and transport the fluidized particles in the heat exchange space 15 to the cyclone separator 11.

[0049] The cyclone separator 11 further includes a first output end for discharging particles and a second output end for discharging gas, the second output end is connected to the first end of the exhaust pipe 13, and is used to separate the heated particles from the air and collect the hot particles, the hot particles are output through the first output end, and the hot air is output through the second output end. The second end of the exhaust pipe 13 is connected to the cold particle storage space 14, and is used to transport the hot air separated by the cyclone separator 11 to the cold particle storage space 14 in the housing 2 to recover the waste heat.

[0050] The particle fluidization section may specifically include a particle fluidizer 7 , an air compressor 10 , an air distribution plate 8 , a flow regulating valve 9 , a particle fluidization pipeline 16 and a check valve 6 .

[0051] The output end of the air compressor 10 is connected to the gas input end of the particle fluidizer 7 for generating pressurized air and outputting the pressurized air to the particle fluidizer 7 to fluidize the particles.

[0052] The input end of the particle fluidizer 7 for inputting particles is connected to the particle output end 17 through a pipeline, and is provided with a flow regulating valve 9 for adjusting the particle flow entering the fluidizer according to the incident solar energy intensity to ensure that the particles are heated to the required temperature. The output end of the particle fluidizer 7 is connected to the accommodating shell through a particle fluidizing pipeline 16 for conveying the fluidized particles to the particle distribution area 5 in the accommodating shell. The particle fluidizing pipeline 16 is provided with a check valve 6 for preventing the fluidized particles in the particle distribution area 5 from flowing back.

[0053] The air distribution plate 8 is arranged at the position where the pressurized air of the particle fluidizer 7 is input, and is used to uniformly send the pressurized air into the particle fluidizer 7 to fluidize the particles.

[0054] The cold particles are fluidized by the particle fluidizer 7, and the particles in the fluidized state are output to the containing shell, so that the fluidized particles exchange heat with the heat pipe in the heat exchange space 15, thereby overcoming the disadvantage of poor thermal conductivity of the particles and improving the efficiency of the heat absorber. The particle flow rate and flow velocity can be controlled by the particle fluidizer, thereby improving the stability of the system and solving the problem of low heat absorption efficiency of the existing particle heat absorber.

[0055] The present embodiment is described below through the flow path of the particles: the fluidized particles enter the particle distribution area 5 through the particle fluidization pipe 16, take away part of the heat of the radiation absorption plate 4, and then enter the heat exchange space 15 in the heat exchange pipe 18 along the outer wall of the heat pipe 3 to quickly exchange heat with the heat pipe 3. The particle collector 12 is connected to the heat exchange space 15 to uniformly collect the heated fluidized particles. The cyclone separator 11 is connected to the particle collector 12, and the particles in the collector enter the cyclone separator 11 under pressure drive, and the cyclone separator 11 separates the particles from the gas.

[0056] The specific operation process of the particle heat absorber of this embodiment is further explained below: before the particle heat absorber is operated, the cold particle storage space 14 in the shell 2 has stored cold particles. First, the flow regulating valve 9 and the air compressor 10 are opened to fluidize the cold particles in the particle fluidizer 7, and then the check valve 6 is opened to allow the fluidized particles to enter the particle distribution area 5 through the particle fluidization pipeline 16, and enter the heat exchange space 15 driven by the pressure provided by the air compressor 10. After that, the mirror field is started, and the radiation absorption plate 4 is heated by the solar radiation from the mirror field and transfers the heat to the heat pipe 3 connected thereto. The liquid metal evaporates due to the heat and flows to the condensation end of the heat pipe 3 under the capillary action. At the same time, the fluid in the particle distribution area 5 will also take away part of the heat of the radiation absorption plate 4 to ensure that the temperature of the radiation absorption plate 4 will not exceed the temperature. The fluidized particles enter the heat exchange space 15 through the particle distribution area 5 and quickly exchange heat with the heat pipe 3. The opening of the flow control valve 9 is controlled to ensure that the particles are heated to the design point temperature. The low-temperature particles outside the particle heat exchange channel are in a static state, and the heat exchange coefficient with the heat exchange tube 18 is very low, which effectively plays the role of the insulation layer. In addition, a small part of the energy dissipated outward by the heat exchange tube 18 is also absorbed by the low-temperature particles and finally used for power generation, which significantly improves the energy utilization rate. Subsequently, the high-temperature particles enter the fluidized particle collector 12 for centralized collection and are then transported to the cyclone separator 11. The cyclone separator 11 separates the high-temperature particles from the hot air, and the high-temperature particles enter the corresponding storage tank, while the high-temperature hot air enters the low-temperature cold particle storage space 14 through the exhaust pipe 13 to recover the waste heat.

[0057] Embodiment 2

[0058] A solar power generation system of the present invention includes the particle heat absorber in the above-mentioned embodiment 1. By arranging the heat exchange part in the shell 2, the gap formed by the accommodation shell and a plurality of heat exchange tubes 18 and the shell 2 is used as the cold particle storage space 14, the cold particle storage tank and the heat absorber are integrated into one, and the space outside the heat exchange part is used as the cold particle storage tank, which not only saves the cold particle storage tank and the cold particle buffer tank, but also simplifies the system structure, saves system space, and greatly reduces system cost.

[0059] The embodiments of the present invention are described in detail above in conjunction with 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 protection scope of the present invention.

Claims

1. A particle heat absorber, characterized in that: It comprises a shell (2), a heat absorbing part and a heat exchanging part; The heat absorbing part is in heat transfer contact with the heat exchanging part; The heat exchange portion is arranged in the shell (2), and forms a cold particle storage space (14) between the heat exchange portion and the shell (2); The heat exchange part comprises a heat pipe (3) and a heat exchange cavity; a heat exchange space (15) is provided between the heat pipe (3) and the heat exchange cavity; The heat exchange cavity comprises a particle distribution area (5) and a particle heat exchange area, the particle distribution area (5) being arranged at one end of the shell (2) adjacent to the heat absorption portion, one end of the particle heat exchange area being in communication with the particle distribution area (5), and the other end being in communication with a particle collector (12) outside the shell (2); The evaporation end of the heat pipe (3) is in heat transfer contact with the heat absorption part, and the condensation end is arranged in the particle heat exchange area; It also comprises a particle fluidizing section, the input end of which is in communication with the cold particle storage space (14), and the output end of which is in communication with the particle distribution area, for fluidizing the particles and outputting them into the heat exchange section.

2. The particle heat absorber according to claim 1, characterized in that The heat exchange cavity comprises at least two particle heat exchange zones.

3. The particle heat absorber according to claim 1, characterized in that: The heat absorbing portion is arranged on one side of the shell (2), and the heat absorbing portion is a radiation absorbing plate (4).

4. The particle heat absorber according to claim 1, characterized in that The heat pipe (3) is filled with liquid metal.

5. The particle heat absorber according to claim 1, characterized in that: Also includes a cyclone separator (11); The input end of the cyclone separator (11) is connected to the particle collector (12); The cyclone separator (11) further comprises a first output end for discharging particles and a second output end for discharging gas; the second output end is in communication with the cold particle storage space (14).

6. The particle heat absorber according to claim 1, characterized in that A particle fluidization pipeline (16) is provided between the output end of the particle fluidization section and the particle distribution area, and the particle fluidization pipeline (16) is provided with a check valve (6).

7. The particle heat absorber according to claim 1, characterized in that: The shell (2) is provided with a particle input end (1) and a particle output end (17) which are in communication with the cold particle storage space (14).

8. A solar power generation system, characterized in that: Comprising a particle heat absorber as described in any one of claims 1 to 7.

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