Particle heat sink

Abstract

The present invention relates to the field of heat absorption and heat storage technology, and specifically provides a particle heat absorber for photothermal power generation, comprising: a feed bin for temporarily storing heat-absorbing particles to be heated; a multi-stage plate heat absorption channel that allows particles to flow along a predetermined path under the action of gravity; the multi-stage plate heat absorption channel is composed of multiple plate structures, and the flow direction of particles changes when they flow from one plate structure to the next adjacent plate structure. The particle heat absorber can achieve the temperature increase of heat-absorbing particles with a simple structure, that is, realize the function of converting solar energy into high-temperature thermal energy.

Description

Technical Field

[0001] The present invention relates to the field of heat absorption and energy storage technology, and in particular to a particle heat absorber for photothermal power generation. Background Art

[0002] In a sense, human development is the development of energy utilization. Currently, the world's energy consumption is still dominated by non-renewable energy, among which coal, oil and natural gas account for 84.3%. The consumption of large amounts of fossil energy has caused great harm to the earth's ecological environment. New energy, especially solar energy, has the advantages of huge total amount, cleanliness and safety, which has attracted widespread attention from scientific researchers.

[0003] Specifically, solar power generation technology mainly includes photovoltaic power generation, solar thermal power generation and hot wind power generation, among which solar thermal power generation is a technology that converts collected solar energy into thermal energy for power generation. In the process of solar thermal power generation, using particles as working medium is generally considered by the scientific research community to be one of the new generation of advantageous technologies, which has the following advantages: particles can work stably at 700℃ or even above 1000℃, thereby supporting high-temperature power generation processes, such as supercritical Rankine cycle, supercritical carbon dioxide Brayton cycle power generation, etc.; particles can not only be used as heat absorption medium, but also directly as heat storage medium, thereby reducing heat storage costs and improving system efficiency; particles themselves are easy to obtain and relatively cheap; high-temperature particles themselves can be used not only for power generation, but also for thermochemical processes such as hydrogen production and coal gasification; particles are obviously safer and more stable than molten salts, which have the risks of low-temperature solidification and high-temperature decomposition.

[0004] At present, the component responsible for converting solar energy into thermal energy in solar thermal power generation technology is the absorber, and its operating performance is directly related to the safe, stable and efficient operation of the entire solar thermal power generation system. At present, the more typical types of particle absorbers in the world include free-fall particle absorbers, obstructed flow particle absorbers, centrifugal particle absorbers, quartz tube particle absorbers, mono-inclined plate particle absorbers, etc. Although various particle absorbers have their own advantages and significance, they also have some problems, such as the particle flow rate of the free-fall absorber is too fast, the heating time is short, resulting in insufficient single-pass temperature rise; the obstruction structure of the obstructed flow particle absorber itself is prone to wear and deformation at high temperature; the structure of the centrifugal particle absorber is relatively complex and requires external power drive; the quartz glass of the quartz tube particle absorber itself is fragile and easy to get dirty; the particle layer at the end of the mono-inclined plate particle absorber is too thick and difficult to match the focusing conditions.

[0005] Therefore, how to provide a heat absorber with a simple structure that can achieve the heating of particles and has a relatively controllable temperature, so as to safely and stably convert solar energy into thermal energy within high-temperature particles, is a problem in the prior art. Summary of the invention

[0006] In view of the above problems, the present invention provides a particle heat absorber for photothermal power generation, which can achieve the temperature increase of heat-absorbing particles with a simple structure, that is, realize the function of converting solar energy into high-temperature thermal energy.

[0007] The core component of the particle heat absorber provided by the present invention includes: a feeding silo for temporarily storing the heat-absorbing particles to be heated, and a multi-stage plate-type heat-absorbing channel that allows the heat-absorbing particles to flow along a predetermined path under the action of gravity, wherein the multi-stage plate-type heat-absorbing channel is composed of multiple plate structures, and the flow direction of the heat-absorbing particles changes when flowing from one of the plate structures to the next adjacent plate structure.

[0008] According to the particle heat absorber provided by the present invention, the feed bin itself has a certain capacity, and the heat-absorbing particles can be temporarily stored in the feed bin, thereby playing a buffering role for the particles entering the heat absorber. The multi-stage plate heat absorption channel allows the heat-absorbing particles to flow along a predetermined path inside it under the action of gravity, and in the process of flowing, they are heated by the focused solar energy. The multi-stage plate heat absorption channel composed of multiple plate structures can increase the total distance of the heat-absorbing particles flowing, extend the time of being heated by the focused solar energy, and allow the heat-absorbing particles to fully absorb the heat of the focused solar energy. In addition, the incident light can also undergo multiple absorption and reflection processes between the plate structures at each level, so that the particles can fully absorb the solar energy. Finally, the average length of each level in the multi-stage structure can also be relatively reduced, thereby reducing the inefficient heat absorption area, reducing the thickness of the terminal particle layer and saving space.

[0009] Therefore, the particle heat absorber provided by the present invention can achieve the temperature increase of the heat-absorbing particles with a simple structure, that is, realize the function of converting solar energy into thermal energy at a high temperature level.

[0010] In a preferred technical solution of the present invention, the plurality of plate structures are any one of the following structures: the plurality of plate structures are inclined plates, on which heat-absorbing particles can flow; the plurality of plate structures are interlayers, the interlayers respectively have an upper plate and a lower plate, and the heat-absorbing particles can flow in the interlayers; the plurality of plate structures are composed of a combination of an inclined plate and an interlayer, the interlayer has an upper plate and a lower plate, and the heat-absorbing particles can flow on the inclined plate or in the interlayer.

[0011] According to the preferred technical solution, the present invention refers to the plate structure that is directly exposed to the focused solar energy and thus directly heated by the focused solar energy as a direct plate, and the direct plate includes but is not limited to an inclined plate or a sandwich lower plate. The direct plate itself can be modified to enhance transmission, reflection or absorption to improve the overall absorption efficiency of the absorber for solar energy.

[0012] According to the preferred technical solution, the direct plate can be made of quartz glass, which has a high transmittance and good thermal stability. At this time, most of the focused solar energy irradiated on the direct plate can pass through the direct plate and directly heat the heat-absorbing particles on the back of the direct plate. A small part of the focused solar energy is reflected by the direct plate and the heat-absorbing particles on the back of the direct plate, thereby heating the heat-absorbing particles of the next-level plate structure.

[0013] According to the preferred technical solution, the direct radiation plate can be made of a ceramic reflector plate, which has a high reflectivity and good thermal stability. At this time, most of the focused solar energy irradiated on the direct radiation plate is reflected by the ceramic reflector plate. The reflected focused solar energy can heat the heat-absorbing particles of the next-level plate structure. A small part of the focused solar energy is absorbed by the ceramic reflector plate and converted into thermal energy of the ceramic reflector plate, thereby indirectly heating the heat-absorbing particles on the back of the ceramic reflector plate.

[0014] According to the preferred technical solution, the direct panel can be coated with a high-temperature resistant far-infrared radiation coating, which can increase the absorption rate of the surface of the direct panel and has good thermal stability. At this time, most of the focused solar energy is absorbed by the direct panel and converted into thermal energy of the direct panel, thereby indirectly heating the heat-absorbing particles on the back of the direct panel. In order to improve the indirect heating efficiency, for the modification to enhance the absorption rate, the direct panel should be as thin as possible and should be made of materials with good thermal conductivity.

[0015] According to the preferred technical solution, the three types of modification solutions for the direct-irradiation plate can be used alone or in combination to achieve the best effect.

[0016] In a preferred technical solution of the present invention, a baffle is additionally installed on the plate structure.

[0017] According to the preferred technical solution, taking the inclined plate with the heated upper surface of the particle layer as an example, a baffle is installed on the inclined plate, which only allows heat-absorbing particles above the baffle to pass through, thereby dividing the particle layer into a non-circulating particle layer below the baffle and an effective circulating particle layer above the baffle. After adding the baffle, the thickness of the effective circulating particle layer is reduced, alleviating the problem of the excessively thick particle layer at the end of the inclined plate of the traditional single-stage plate heat absorber.

[0018] In a preferred technical solution of the present invention, a light inlet is provided at a position opposite to the multi-stage plate-type heat absorption channel, and a transparent window is installed at the light inlet in a detachable manner. The material of the transparent window should have high transmittance and thermal stability, including but not limited to quartz glass.

[0019] According to the preferred technical solution, the transparent window can be used to isolate external wind and rain, avoid internal particle loss and reduce heat dissipation loss of the heat absorber. The transparent window is installed at the light entrance in a detachable manner, so that it can be installed or disassembled according to actual needs, thereby maximizing efficiency while ensuring the safe and stable operation of the particle heat absorber.

[0020] In a preferred technical solution of the present invention, the particle heat absorber also includes a temperature control device, a connecting funnel for receiving the heat absorbing particles leaving the multi-stage plate-type heat absorbing channel, and a storage bin connected to the connecting funnel.

[0021] According to the preferred technical solution, the temperature control device can adjust the particle flow rate, particle temperature distribution and outlet particle temperature according to the real-time operating conditions. The connecting funnel is V-shaped and can connect two flow sections with different calibers. The storage bin has a certain capacity and can be used to temporarily store high-temperature heat-absorbing particles after absorption of heat.

[0022] In a preferred technical solution of the present invention, the temperature control device includes a flow control valve, a temperature sensor and a processor. The connecting funnel is connected to the flow control valve, so that the flow control valve can control the particle flow through the corresponding connecting funnel. The temperature sensor is arranged at a temperature measuring point on the connecting funnel and / or the multi-stage plate-type heat absorption channel. The processor receives a temperature signal from the temperature sensor and outputs a control signal to the flow control valve.

[0023] According to the preferred technical solution, temperature sensors are arranged at important temperature measuring points connecting the funnel and / or the multi-stage plate-type heat absorption channel to monitor the temperature of the heat absorbing particles at various locations of the heat absorber and send temperature signals to the processor. The processor outputs a control signal to the flow control valve based on actual working conditions, and the flow control valve is used to adjust the temperature of the heat absorbing particles in various parts of the heat absorber.

[0024] In a preferred technical solution of the present invention, a plurality of connecting funnels are provided, and a plurality of flow control valves are correspondingly provided.

[0025] According to this preferred technical solution, the particle flow through the corresponding connecting funnels can be controlled by flow control valves in different areas, thereby controlling the particle flow in the multi-stage plate-type heat absorption channel facing each connecting funnel, and finally adjusting the particle temperature of each part of the heat absorber. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of a method for utilizing concentrated solar energy according to an embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of the overall structure of a particle heat absorber used for tower-type focusing in an embodiment of the present invention;

[0028] Figure 3is an isometric cross-sectional view of a particle heat absorber for tower-type concentration in an embodiment of the present invention;

[0029] Figure 4 It is a schematic diagram of the internal particle flow and light path of a plate-type structure of a multi-stage plate-type heat absorption channel of a particle heat absorber for tower-type focusing in an embodiment of the present invention;

[0030] Figure 5 is a schematic diagram of internal particle flow and light path of another plate-type structure in an embodiment of the present invention;

[0031] Figure 6 Schematic diagram of internal particle flow and light path of another plate-type structure in an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the solar energy absorption and reflection process at point D based on a quartz glass transmission plate;

[0033] Figure 8 This is a schematic diagram of the solar energy absorption and reflection process at point E based on the ceramic reflector;

[0034] FIG9( a ) is a schematic diagram showing the principle that the end particle layer of a single board is too thick due to a long travel;

[0035] Figure 9(b) is a schematic diagram of the principle of the baffle at the end of the inclined plate;

[0036] Fig.10 Schematic diagram of the horizontal arrangement of the connecting funnel and the flow control valve according to an embodiment of the present invention;

[0037] Fig.11 2 is a control schematic diagram of a temperature control device according to an embodiment of the present invention.

[0038] Reference numerals:

[0039] 1-feeding bin; 2-multi-stage plate heat absorption channel; 20-interlayer; 200-interlayer upper plate; 201-interlayer lower plate; 2010-quartz glass transmission plate; 2011-ceramic reflection plate; 21-inclined plate; 22-baffle; 3-connecting funnel; 4-temperature control device; 40-flow control valve; 41-temperature sensor; 42-processor; 43-electric pumping rod; 5-transparent window; 6-storage bin; 7-heliostat field; 8-heat absorption tower; 9-light inlet; a-particle flow direction; b-sunlight irradiation path; c-heat flow direction; Point D-radiation energy absorption reflection point; Point E-radiation energy absorption reflection point. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0042] Figure 1 It is a schematic diagram of the utilization method of focusing solar energy of the present invention, such as Figure 1 As shown, the device for converting solar energy into thermal energy mainly includes two parts, namely a focusing part and a heat absorption part. After the sunlight is focused by the heliostat field 7, it is concentrated through the light inlet 9 to irradiate the particle heat absorber in the heat absorption tower 8, thereby heating the heat absorption particles inside the heat absorber. The heated heat absorption particles can enter other equipment such as a heat exchanger for heat transfer, thereby further utilizing the heat energy in the particles.

[0043] Figure 2 It is a schematic diagram of the overall structure of the particle heat absorber used for tower-type focusing of the present invention. Figure 3 1 is an isometric cross-sectional view of a particle heat absorber for tower-type focusing in the present invention. Figure 2 and Figure 3 It can be seen that the particle heat absorber provided in the present invention includes: a feeding silo 1 for temporarily storing the heat-absorbing particles to be heated, a multi-stage plate heat absorption channel 2 that allows the particles to flow along a predetermined path under the action of gravity and be heated by the focused solar energy in the process, a connecting funnel 3 connecting the multi-stage plate heat absorption channel 2 and the flow control valve 40, and a storage silo 6 for temporarily storing the outlet high-temperature particles.

[0044] In the particle heat absorber provided in this embodiment, the feed bin 1 itself has a certain capacity. The heat-absorbing particles first enter the feed bin 1 from the outside for buffering and are temporarily stored in the feed bin 1. Then, the heat-absorbing particles enter the multi-stage plate heat absorption channel 2 through a slit (not shown) under the action of gravity, and flow downward step by step along a predetermined path in the multi-stage plate heat absorption channel 2 under the action of gravity. In this process, they are heated by the focused solar energy entering through the transparent window 5. Finally, the heated heat-absorbing particles enter the connecting funnel 3 from the end of the multi-stage plate heat absorption channel 2. The multi-stage structure of the multi-stage plate heat absorption channel 2 can increase the flow distance of the heat-absorbing particles and extend the time of being heated by the focused solar energy, so that the heat-absorbing particles can fully absorb the heat of the focused solar energy. In addition, the incident light can also undergo multiple absorption and reflection processes between the multi-stage structures, so that the particles can fully absorb the solar energy. Finally, the average length of each stage in the multi-stage structure can also be relatively reduced, thereby reducing the inefficient heat absorption area, reducing the thickness of the terminal particle layer and saving space.

[0045] Therefore, the particle heat absorber provided by the present invention can achieve the temperature increase of the heat-absorbing particles with a simple structure, that is, realize the function of converting solar energy into thermal energy at a high temperature level.

[0046] Figure 4-Figure 6 It shows a schematic diagram of the internal particle flow and light path of three plate structures of a multi-stage plate heat absorption channel 2 of a particle heat absorber for tower focusing in an embodiment of the present invention.

[0047] Reference Figure 4 The multi-stage plate heat absorption channel 2 is composed of a plurality of plate structures, which are alternately composed of adjacent inclined plates 21 and interlayers 20. The interlayer 20 has an upper plate 200 and a lower plate 201. The upper plate 200 and the lower plate 201 are adjacently arranged to allow heat absorption particles to pass between the two. Figure 4 When the lower plate 201 is directly incident on the lower side, the lower plate 201 is a direct incident plate. However, the present invention is not limited to Figure 4 In the case where the lower plate 201 is a direct plate, those skilled in the art can understand that the direct plate is a plate structure that is directly exposed to the focused solar energy and directly heated by the focused solar energy. Therefore, based on the technical solution of the present invention, the technicians can select a reasonable position of the direct plate according to the incident angle of the sunlight in actual applications.

[0048] In this embodiment, the heat-absorbing particles pass through the interlayer 20 and the inclined plate 21 in sequence under the action of gravity. The interlayer 20 and the inclined plate 21 are arranged alternately, and the angles of the interlayer 20 and the inclined plate 21 are about 5° larger than the particle repose angle. The arrangement of the inclined plate 21 and the interlayer 20 realizes the multi-level utilization of the focused solar energy and improves the utilization efficiency of the focused solar energy.

[0049] In some embodiments of the present invention, more preferably, the lower plate 201 is made of quartz glass.

[0050] Specifically, the lower plate 201 made of quartz glass is referred to as a quartz glass transmission plate 2010. The quartz glass transmission plate 2010 should have a high transmittance and good thermal stability.

[0051] Figure 7 This is a schematic diagram of the solar energy absorption and reflection process based on the D point of the quartz glass transmission plate 2010, wherein a is the particle flow direction, b is the sunlight route, and c is the heat flow direction. Specifically, most of the focused solar energy incident on the quartz glass transmission plate 2010 will heat the heat-absorbing particles in the interlayer 20 through the quartz glass transmission plate 2010, and a small part of the focused solar energy is reflected by the quartz glass transmission plate 2010. Most of the transmitted focused solar energy can be absorbed by the flowing particle layer on the back of the quartz glass transmission plate 2010, and a small part is reflected by the flowing particle layer. Most of the above-mentioned reflected focused solar energy is absorbed by the flowing particle layer on the inclined plate 21 of the next level of the interlayer 20, and a small part escapes after multiple reflections. The lower plate 201 in this embodiment uses the high transmittance characteristic of quartz glass, so that most of the solar energy focused by the heliostat field 7 can be directly absorbed by the heat-absorbing particles through the lower plate 201. Since the heat-absorbing particles need to work stably at 700° C. or even above 1000° C., the higher thermal stability of quartz glass can make the lower plate 201 more resistant to high temperatures, thereby preventing the lower plate 201 from being deformed due to high temperature during operation, which would result in the solar energy being unable to be safely and stably converted into thermal energy for utilization.

[0052] In some other embodiments of the present invention, more preferably, the lower plate 201 may also be composed of a ceramic reflective plate 2011 . The difference from the above embodiment is that the original quartz glass transmission plate 2010 is replaced by the ceramic reflective plate 2011 .

[0053] Figure 8 This is a schematic diagram of the solar energy absorption and reflection process at point E based on the ceramic reflector 2011, wherein a is the particle flow direction, b is the sunlight route, and c is the heat flow direction. Specifically, most of the focused solar energy incident on the ceramic reflector 2011 is reflected by the ceramic reflector 2011, and most of this reflected radiation energy is absorbed by the flowing particle layer on the lower level inclined plate 21 of the interlayer 20, and a small part escapes after multiple reflections. The focused solar energy absorbed by the ceramic reflector 2011 will be converted into the thermal energy of the ceramic reflector 2011, thereby indirectly heating the particles flowing in the interlayer 20.

[0054] Specifically, in this embodiment, the lower plate 201 of the interlayer 20 that carries particles and is directly irradiated by the focused solar energy in the multi-stage plate-type heat absorption channel 2 can be replaced or added with a material that increases reflectivity to guide this part of the solar energy to heat particles at other positions through reflection; transparent materials can also be replaced as this part of the material to transmit solar energy to heat particles that can only be heated indirectly. The above two solutions should be used one or a combination of the two according to actual needs to match the upper focusing incident conditions such as tower focusing.

[0055] In the present invention, in addition to the interlayer lower plate 201, other components can be made of quartz glass or ceramic reflector plates, and can also be made of 310s stainless steel, silicon carbide plates, mullite plates and other high temperature resistant materials according to actual working conditions. In some embodiments of the present invention, preferably, a baffle 22 is installed at the end of the inclined plate 21.

[0056] In this embodiment, the baffle 22 only allows heat-absorbing particles above the baffle 22 to pass through, thereby dividing the particle layer into a non-circulating particle layer below the baffle 22 and an effective circulating particle layer above the baffle 22. After adding the baffle 22, the thickness of the effective circulating particle layer is reduced, alleviating the problem of the excessively thick particle layer at the end of the inclined plate 21 of the traditional single-stage plate-type particle heat absorber.

[0057] Based on the problem of too thick particle layer at the end of inclined plate 21 in the traditional single-stage plate particle heat absorber, the reason for the problem of too thick particle layer at the end of inclined plate 21 of the single-stage plate particle heat absorber is explained here in conjunction with the accompanying drawings. FIG9(a) is a schematic diagram of the principle that the particle layer at the end is too thick due to the long stroke of the single plate. Referring to FIG9(a), in order for the particles to flow under the action of gravity, the inclination angle β of the inclined plate 21 should be greater than the repose angle α of the particles. In actual use, the angle difference should be more than 2° to ensure stable flow of particles. Since the inclination angle β of the inclined plate 21 is greater than the repose angle α of the particles, when the particles move slowly in the form of a moving bed, the difference in particle thickness at points A and B with a distance of l is Δd=d1-dd2=l*(tanβ-tanα). Since tanβ-tanα>0, the thickness of the particle layer downward along the inclined plate 21 will gradually increase with the increase of l. Compared with the single-stage plate structure, the multi-stage plate structure divides the heating stroke into multiple stages from top to bottom. While the total heating stroke remains unchanged, the stroke of each stage is reduced, that is, l in Figure 9(a) is reduced, thereby alleviating the problem of an excessively thick particle layer at the end. In addition, the present invention can further reduce the thickness of the particle layer through structural improvement design, that is, adding a baffle 22. Figure 9(b) is a schematic diagram of the principle of the baffle 22 at the end of the inclined plate 21. Referring to Figure 9(b), for the problem of the terminal particle layer being too thick, a baffle 22 with a height of d3 is added at the end of the inclined plate 21, so that only particles higher than the baffle 22 are allowed to pass through, and the particle layer is divided into a non-circulating particle layer below the baffle 22 and an effective circulating particle layer above the baffle 22. The non-circulating particle layer can be theoretically regarded as a thermal insulation material because it will not participate in the working fluid circulation of the system. The effective circulating particle layer obviously reduces the thickness of the circulating particle layer compared to the total particle layer, that is, the thickness of the particle layer at the terminal of the inclined plate after the end baffle 22 is added becomes: D′2=d2-d3. Therefore, the use of a multi-stage plate structure and the addition of a baffle 22 can alleviate the problem of the terminal particle layer being too thick compared to the traditional single-stage plate structure.

[0058] refer to Figure 5 The multi-stage plate-type heat absorption channel 2 is composed of a plurality of plate-type structures, and the plurality of plate-type structures are inclined plates 21, and the heat absorption particles flow on the inclined plates 21. Figure 5 In the case of direct sunlight from below, part of the inclined plate 21 is a direct plate. A baffle 22 is installed on the inclined plate 21. Preferably, the baffle 22 is formed at the end of the inclined plate. The inclined plate 21 set as a direct plate can be made of quartz glass, or can be formed of a ceramic reflector, or coated with a high temperature resistant far infrared radiation coating. Its role and function refer to the above description and will not be repeated.

[0059] refer to Figure 6The multi-stage plate heat absorption channel 2 is composed of a plurality of plate structures, each of which is a sandwich 20, and the sandwich 20 has an upper plate 200 and a lower plate 201, and the upper plate 200 and the lower plate 201 are adjacently arranged to allow heat absorption particles to pass therebetween. Figure 6 In the case of direct sunlight from below, the lower plate 201 is a direct plate. A baffle 22 is installed on the lower plate 201. Preferably, the baffle 22 is formed at the end of the lower plate 201. The lower plate 201 as a direct plate can be made of quartz glass, or can be formed of a ceramic reflector, or coated with a high temperature resistant far infrared radiation coating. Its role and function refer to the above description and will not be repeated.

[0060] Preferably, refer to Figure 1 and Figure 2 A light inlet 9 is provided at a position opposite to the multi-stage plate-type heat absorption channel 2, and the transparent window 5 is detachably mounted on the light inlet 9.

[0061] In this embodiment, the transparent window 5 can be used to isolate external wind and rain, avoid internal particle loss and reduce heat dissipation loss of the heat absorber. The transparent window 5 is installed at the light entrance 9 in a detachable manner, so that it can be installed or disassembled according to actual needs, thereby achieving maximum efficiency while ensuring the safe and stable operation of the particle heat absorber.

[0062] Specifically, in this embodiment, a detachable transparent window 5 is arranged at the light inlet 9, and the material of the transparent window 5 is preferably quartz glass. On the one hand, the transparent window 5 can effectively alleviate the influence of external wind and rain on the normal operation of the internal heat absorber. The detachability of the transparent window 5 and its special quartz glass material can also be used to improve the total efficiency of the heat absorber under different incident radiation intensities. Specifically, when the incident radiation intensity is low, the radiation convection loss of the internal structure of the heat absorber itself accounts for the main part, and the installation of the transparent window 5 can reduce the radiation convection loss and thus improve the total efficiency of the heat absorber; when the incident radiation intensity is high and the radiation convection loss of the internal structure of the heat absorber itself accounts for a low proportion, and the optical loss caused by the reflection of the transparent window 5 at the light inlet 9 of the heat absorber cannot be ignored, removing the transparent window 5 may improve the total efficiency of the heat absorber. The specific choice should be judged according to the specific situation; on the other hand, the transparent window 5 in this embodiment is detachable, so that when the transmittance of the transparent window 5 decreases due to dust, water stains, etc., it can be removed for cleaning and restoration.

[0063] The transparent window 5 in this embodiment can be made of quartz glass material, or other high temperature resistant and high transmittance materials. In addition, the light inlet 9 in this embodiment is rectangular, so the transparent window 5 is also rectangular. For other shapes of light inlet 9, the transparent window 5 should also be selected in a corresponding shape. The transparent window 5 can be a single quartz glass plate, or it can be composed of multiple quartz glass plates spliced ​​together, as long as it can ensure that most radiation energy enters the heat absorber under the premise of isolating external wind and rain and avoiding the loss of internal particles.

[0064] Fig.10 : is a schematic diagram of the horizontal arrangement of the connecting funnel 3 and the flow control valve 40 according to an embodiment of the present invention, Fig.11 4 is a control schematic diagram of the temperature control device 4 according to an embodiment of the present invention. Fig.10 and Fig.11 The particle heat absorber further comprises a temperature control device 4, a connecting funnel 3 and a storage bin 6 connected to the connecting funnel 3. More preferably, the temperature control device 4 comprises a flow control valve 40, a temperature sensor 41 and a processor 42. The flow control valve 40 can control the particle flow rate. The temperature sensor 41 is arranged at an important temperature measuring point of the connecting funnel 3 and the multi-stage plate heat absorbing channel 2. The processor 42 receives a temperature signal from the temperature sensor 41 and outputs a control signal to the flow control valve 40.

[0065] In this embodiment, the temperature control device 4 can adjust the particle flow, particle temperature distribution and outlet particle temperature according to the real-time operation conditions. The connecting funnel 3 is used to transfer the heat absorbing particles transmitted from the multi-stage plate heat absorbing channel 2 to the flow control valve 40. The storage bin 6 has a certain capacity and can be used to temporarily store the high-temperature heat absorbing particles after heat absorption. The temperature sensor 41 is set at the important temperature measuring point connecting the funnel 3 and the multi-stage plate heat absorbing channel 2 to monitor the particle temperature at various locations of the heat absorber and send the temperature signal to the processor 42. The processor 42 outputs a control signal to the flow control valve 40 in combination with the actual working conditions. The flow control valve 40 is used to adjust the temperature of the heat absorbing particles at various locations of the heat absorber to ensure that the heat absorber can operate safely and stably.

[0066] Specifically, refer to Fig.11 The temperature sensor 41 can monitor the temperature of the particles at the end of the connecting funnel 3 in real time, and transmit the temperature signal to the processor 42. When the monitored particle temperature is higher than the expected particle temperature, the processor 42 instructs the electric pumping rod 43 to shorten the operation, thereby driving the flow control valve 40 to open wider and increase the particle flow through the flow control valve 40. When the particle flow increases, the time the particles spend in the multi-stage plate-type heat absorption channel 2 becomes shorter, so that the average radiation energy absorbed by the particles decreases, thereby reducing the particle temperature until the particle temperature measured by the temperature sensor 41 is close to the expected particle temperature. Otherwise, the opposite operation can be performed.

[0067] The flow control valve 40 in the present embodiment can adopt a pumping plate valve to control the particle flow. It should be noted that other types of valves, such as pneumatic control valves, etc., can also be used according to actual conditions, as long as the function of regulating the particle flow can be played. The temperature sensor 41 in the present embodiment is a sensor that can sense the temperature and convert it into an available output signal, which can be a thermocouple, thermistor, etc. The processor 42 in the present embodiment includes an arithmetic logic component, a register component, an arithmetic unit and a control component, etc., for example, it can be a computer, etc.

[0068] Preferably, refer to Figure 8 There are multiple connecting funnels 3 , and there are correspondingly multiple flow control valves 40 to control the amount of particles flowing through each connecting funnel 3 respectively.

[0069] In this embodiment, the flow control valves 40 in different areas can be used to control the amount of particles in the directly connected connecting funnel 3, thereby controlling the particle flow in the multi-stage plate-type heat absorption channel 2 facing each connecting funnel 3, and finally adjusting the particle temperature of each part.

[0070] Specifically, if Fig.10 As shown, three connecting funnels 3 are arranged in the left, middle and right directions, three flow control valves 40 are arranged in the left, middle and right directions, and three sets of temperature control devices 4 are arranged in the left, middle and right directions. The processor 42 can be shared to deal with the problem of uneven incident light spot in the lateral direction. In this embodiment, the specific working method is explained by taking the higher energy flow density in the middle and the lower energy flow density on the left and right sides as the actual working conditions: at this time, since the energy flow density in the middle part is higher and the energy flow density on both sides is lower, the temperature of the particles in the middle is higher, while the temperature of the particles on the left and right sides is lower. The temperature values ​​at the ends of the three connecting funnels 3 in the left, middle and right directions are monitored in real time, and the three flow control valves 40 in the left, middle and right directions are adjusted according to the specific working method of the above-mentioned temperature control device 4, so as to adjust the particle temperature values ​​at the ends of the three connecting funnels 3 in the left, middle and right directions to a state that is relatively uniform and close to the expected temperature value.

[0071] In addition, it should be noted that the particle heat absorber is also provided with an insulation structure (not shown) to increase the particle temperature and the efficiency of the heat absorber. The insulation structure in the particle heat absorber can be an insulation cover. First, the insulation cover (not shown) in the particle heat absorber is made of a high-temperature resistant aluminum silicate ceramic fiber blanket. It can be understood by those skilled in the art that although the insulation cover described in the preferred embodiment is made of a high-temperature resistant aluminum silicate ceramic fiber blanket, it can be understood that the technician can also select other materials and structures with insulation effects according to actual use requirements. Secondly, the heat absorbing particles in this embodiment are bauxite ceramsite sand and iron-manganese oxide particles. Because bauxite ceramsite sand is cheap and easy to obtain, and has good high temperature resistance, the doping of iron-manganese oxide can increase the overall specific heat of the working fluid, thereby reducing the subsequent heat storage space and heat storage cost. Although bauxite ceramsite sand and iron-manganese oxide particles are used as working fluids in this embodiment, it is not limited to this. Obviously, the technician can also select other particles with high absorption rate and high temperature resistance according to actual use requirements.

[0072] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A particle heat absorber, characterized in that: include: Feeding silo, used to temporarily store heat-absorbing particles to be heated; The multi-stage plate-type heat absorption channel allows the heat absorption particles to flow along a predetermined path under the action of gravity. The multi-stage plate-type heat absorption channel is composed of a plurality of plate-type structures, and the flow direction of the heat absorption particles changes when flowing from one of the plate-type structures to the next adjacent plate-type structure. The plurality of plate structures are all inclined plates and / or interlayers, and the heat absorbing particles can flow on the inclined plates and / or in the interlayers, and the interlayers have an upper plate and a lower plate; The sunlight is directly irradiated from the bottom of the particle heat absorber to the direct plate, which is a plate-type structure exposed to the solar energy and directly focused and heated. The direct plate is the inclined plate or the lower plate. The directing plate has a modification for enhancing transmission, and / or a modification for enhancing reflection, and / or a modification for enhancing absorption; A baffle is installed at the end of the plate structure.

2. The particle heat absorber according to claim 1, characterized in that A light inlet is arranged at a position opposite to the multi-stage plate-type heat absorption channel, and a transparent window is detachably mounted on the light inlet, wherein the material of the transparent window includes quartz glass.

3. The particle heat absorber according to claim 1, characterized in that: It also includes a temperature control device, a connecting funnel for receiving heat absorbing particles from the multi-stage plate-type heat absorbing channel, and a storage bin connected to the connecting funnel.

4. The particle heat absorber according to claim 3, characterized in that: The temperature control device includes a flow control valve, a temperature sensor and a processor. The flow control valve is configured to control the amount of particles flowing through the connecting funnel. The temperature sensor is arranged at a temperature measuring point of the connecting funnel and / or the multi-stage plate-type heat absorption channel. The processor receives a temperature signal from the temperature sensor and outputs a control signal to the flow control valve.

5. The particle heat absorber according to claim 4, characterized in that: The connecting funnel is provided in plurality, and the flow control valve is correspondingly provided in plurality to respectively control the particle flow through the corresponding connecting funnel, thereby adjusting the particle temperature of each part of the particle heat absorber.

Images