A trough type solar thermal system

Abstract

The application discloses a trough type photo-thermal system, and belongs to the technical field of energy sources. The trough type photo-thermal system comprises a trough type heat collecting device, a hot particle storage tank, a heat releasing device, a cold particle storage tank, a power fan and a waste heat recovery device. The trough type heat collecting device is used for collecting solar light energy and converting the solar light energy into heat energy. The heat carrying particles are used as heat medium. The power fan is used for providing conveying air so that the heat carrying particles flow along the heat collecting channel in the trough type heat collecting device and absorb the heat energy. The heat releasing device is connected with a heat using equipment and is used for releasing the heat energy absorbed by the heat carrying particles to supply heat to the heat using equipment. The waste heat recovery device is connected with the trough type heat collecting device and is used for recovering the heat energy which is not completely absorbed by the heat carrying particles. The waste heat recovery device is also connected with the output end of the power fan and / or the heat using equipment to preheat the conveying air and / or supply heat to the heat using equipment. The application breaks through the temperature upper limit of the traditional trough type photo-thermal system, reduces heat loss, improves heat energy utilization efficiency and heat storage capacity, and reduces the equipment cost.

Description

Technical Field

[0001] This application relates to the field of energy utilization technology, and more specifically, to a trough-type solar thermal system. Background Technology

[0002] With the continuous growth of global energy demand and the increasing severity of environmental problems, solar thermal technology, as a clean and renewable energy utilization method, is gradually becoming an ideal alternative to traditional fossil fuels. Solar trough thermal systems utilize collectors to convert solar radiation energy into heat energy, which is then transferred to the heat medium through a heat exchanger. They are widely used in power generation, heating, and industrial steam production. In recent years, the research and application of solar thermal technology have made continuous progress, especially trough thermal systems, which, due to their high thermal efficiency and large thermal energy storage capacity, have become an important technological direction in the field of solar thermal power generation. With policy support and technological maturity, solar trough thermal systems have broad prospects for future industrial applications and global energy transition.

[0003] The application of parabolic trough solar thermal systems in solar power plants enables long-term thermal energy storage, improving the system's energy utilization rate and providing a continuous and stable heat source for industrial production, especially in scenarios requiring high-temperature steam. However, current parabolic trough solar thermal systems have relatively low upper operating temperature limits and limited total heat storage capacity. Reducing heat loss requires significant costs, greatly limiting the system's economic viability and long-term operational stability. Summary of the Invention

[0004] This application aims to provide a trough-type solar thermal system, which addresses the problems of limited heat storage capacity, high cost, and low reliability in existing systems.

[0005] A parabolic trough solar thermal system, comprising:

[0006] Trough-type solar collectors, hot pellet storage tanks, heat release devices, and cold pellet storage tanks;

[0007] The cold particle storage tank stores heat-carrying particles. The trough-type solar collector has a heat-collecting channel. The inlet end of the heat-collecting channel is connected to the outlet end of the cold particle storage tank, and the outlet end of the heat-collecting channel is connected to the inlet end of the hot particle storage tank. The trough-type solar collector is used to collect solar energy and convert it into heat energy. The heat-carrying particles can flow along the heat-collecting channel and absorb heat energy. The hot particle storage tank is used to temporarily store the heat-carrying particles after absorbing heat energy. The inlet end of the heat release device is connected to the outlet end of the hot particle storage tank, and the outlet end of the heat release device is connected to the inlet end of the cold particle storage tank. The heat release device is connected to heat-using equipment and is used to release the heat energy absorbed by the heat-carrying particles to supply heat to the heat-using equipment.

[0008] A power fan is connected to the outlet end of the cold particle storage tank to provide conveying air for the flow of the heat-carrying particles;

[0009] A waste heat recovery device is connected to the trough-type heat collection device to recover heat energy that is not completely absorbed by the heat-carrying particles; the waste heat recovery device is also connected to the output end of the power fan and / or the heat-using equipment to preheat the conveying air and / or supply heat to the heat-using equipment.

[0010] Optionally, the trough-type heat collection device includes a heat collection inner tube, and the heat collection channel is formed inside the heat collection inner tube;

[0011] The waste heat recovery device includes: a heat recovery sleeve, which is sleeved on the outer periphery of the inner heat collection tube and coaxially arranged with the inner heat collection tube, and the gap between the heat recovery sleeve and the inner heat collection tube forms a heat recovery channel; and a circulating fan, which is connected to the input end of the heat recovery sleeve and is used to provide circulating air to the heat recovery channel, and the circulating air flows through the heat recovery channel and recovers the heat energy of the inner heat collection tube.

[0012] Optionally, the number of the heat collection inner tubes is set to multiple, and the multiple heat collection inner tubes are distributed in a two-dimensional array along a first direction and a second direction; along the first direction, multiple heat collection inner tubes in the same column are connected in series through pipelines; along the second direction, multiple columns of heat collection inner tubes are connected in parallel through pipelines.

[0013] Optionally, the heat recovery sleeves are arranged in the same number and position as the heat collection inner tubes; along the first direction, multiple heat recovery sleeves in the same column are connected in series through pipelines; along the second direction, multiple columns of heat recovery sleeves are connected in parallel through pipelines.

[0014] Optionally, the heat recovery sleeves are arranged in the same number and position as the heat collection inner tubes; along the second direction, multiple heat recovery sleeves in the same row are connected in parallel through pipelines; along the first direction, multiple rows of heat recovery sleeves are connected in parallel through pipelines.

[0015] Optionally, the trough-type solar collector further includes a bottom support and a concentrator. The concentrator is mounted on the bottom support, with its concave surface facing the outer wall of the inner solar collector tube. The concentrator is used to receive sunlight and focus the light onto the inner solar collector tube through reflection.

[0016] Optionally, the diameter ratio of the inner heat collection tube to the heat recovery sleeve is 0.5 to 0.9.

[0017] Optionally, the heat release device includes any one of a fluidized bed, a moving bed, and a descending bed.

[0018] Optionally, the heat-carrying particles include any one of alumina, quartz sand, and ceramic particles.

[0019] Optionally, the outer wall of the inner heat-collecting tube is provided with a heat-absorbing material.

[0020] Optionally, the flow direction of the circulating air is the same as or opposite to the flow direction of the heat-carrying particles in the inner tube of the heat collector.

[0021] Optionally, the heat particle storage tank, the heat release device, and the pipeline connecting the inner heat collection pipe are all provided with heat insulation material.

[0022] Optionally, the particle size of the heat-carrying particles is 0μm~120μm, preferably 30μm~80μm.

[0023] Optionally, the flow velocity of the heat-carrying particles in the inner heat-collecting tube is 1.5 m / s to 6 m / s.

[0024] Optionally, the particle concentration of the heat-carrying particles flowing in the inner heat-collecting tube is 100 kg / m³. 3 ~500kg / m 3 .

[0025] Optionally, the temperature of the heat-carrying particles after being heated by the trough-type heat collection device is 350℃~900℃, preferably 750℃~800℃.

[0026] Optionally, the velocity of the circulating air is 0.1 m / s to 1 m / s, preferably 0.2 m / s to 0.5 m / s.

[0027] Beneficial effects:

[0028] The parabolic trough solar thermal system described in this application includes a parabolic trough collector, a hot pellet storage tank, a heat release device, a cold pellet storage tank, a power fan, and a waste heat recovery device. By using heat-carrying pellets as the heat medium, it breaks through the upper limit of the operating temperature of traditional parabolic trough solar thermal systems, enabling the system to operate stably in a higher temperature range of 600℃-900℃, meeting the high-temperature industrial steam demand, and significantly improving thermal energy utilization efficiency and energy storage capacity. The power fan provides conveying air for the flow of heat-carrying pellets, forming a gas-solid flow heat transfer mode. By adjusting the flow rate of heat-carrying pellets, the heat load can be flexibly adjusted according to changes in light intensity, expanding the flexibility of the operating load range and enhancing the stability and adaptability of the system in practical applications. The waste heat recovery device recovers the heat energy that is not completely absorbed by the heat-carrying pellets, which is used for preheating the conveying air or directly for heating the heat-using equipment, optimizing the heat energy recovery and transmission path, reducing heat loss, and improving heat transfer efficiency. The trough-type solar thermal system provided in this application adopts a gas-solid flow heat transfer structure and a simplified system design, which improves thermal efficiency while significantly reducing equipment cost and solves the problems of high cost and low reliability of traditional systems. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the trough-type solar thermal system proposed in Embodiment 1 of this application;

[0031] Figure 2 This is a schematic diagram of the trough-type solar thermal system proposed in Embodiment 2 of this application;

[0032] Figure 3 This is a schematic diagram illustrating the working principle of the trough-type solar collector in a trough-type solar thermal system according to an embodiment of this application.

[0033] Figure 4 This is a schematic diagram of the flow relationship between heat-carrying particles and circulating air in a trough-type solar thermal system proposed in one embodiment of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Trough-type solar collector; 101. Inner collector tube; 102. Bottom support; 103. Concentrating mirror; 2. Hot pellet storage tank; 3. Heat release device; 4. Cold pellet storage tank; 5. Power fan; 61. Circulating fan; 62. Heat recovery sleeve; 63. Circulating air duct; 7. Gas-solid transport pipeline; 8. Particle transport pipeline; 9. Evaporation heat exchange tube bundle; 10. Steam drum; 11. Steam pressure reducing station; 12. Steam turbine generator set; 13. Heat exchanger; A. Heat-carrying pellet inlet; B. Heat-carrying pellet outlet; C. Circulating air inlet; D. Circulating air outlet. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] In related technologies, parabolic trough solar thermal systems, by arranging collector tubes in a trough shape and using concentrators to focus solar radiation onto the surface of the collector tubes, transfer heat to the heat transfer medium. They are widely used in solar power generation and industrial heat supply. However, parabolic trough solar thermal systems still face some technical bottlenecks in practical applications. First, traditional parabolic trough solar thermal systems mostly use heat transfer oil as the heat transfer medium. However, due to the low boiling point of heat transfer oil, generally not exceeding 380℃, the system's operating temperature is limited, failing to meet the demands of high-temperature industrial steam, and the total heat storage capacity is limited. Second, to reduce heat loss, existing systems mostly use vacuum collector tubes. Although this improves thermal efficiency, its high cost and low reliability limit the system's economic efficiency and long-term operational stability. Furthermore, parabolic trough solar thermal systems have low operating load flexibility, making it difficult to cope with rapid load fluctuations when sunlight intensity changes.

[0038] In view of this, this application proposes a trough-type photothermal system.

[0039] Example 1

[0040] The parabolic trough solar thermal system provided in this embodiment is applied in a medium-sized chemical plant to provide high-temperature industrial steam to meet the thermal energy requirements of its production process.

[0041] See Figure 1A trough-type solar thermal system includes: a trough-type solar collector 1, a hot particle storage tank 2, a heat release device 3, and a cold particle storage tank 4; the cold particle storage tank 4 stores heat-carrying particles; the trough-type solar collector 1 has a heat collection channel, the inlet end of which is connected to the outlet end of the cold particle storage tank 4, and the outlet end of which is connected to the inlet end of the hot particle storage tank 2; the trough-type solar collector 1 is used to collect solar energy and convert it into heat energy; the heat-carrying particles can flow along the heat collection channel and absorb heat energy; the hot particle storage tank 2 is used to temporarily store the heat-carrying particles after absorbing heat energy; the inlet end of the heat release device 3 is connected to the outlet end of the cold particle storage tank 4. The outlet end of the hot particle storage tank 2 is connected to the outlet end of the heat release device 3, which is connected to the inlet end of the cold particle storage tank 4. The heat release device 3 is connected to the heat-using equipment and is used to release the heat energy absorbed by the heat-carrying particles to supply heat to the heat-using equipment. The power fan 5 is connected to the outlet end of the cold particle storage tank 4 and is used to provide conveying air for the flow of the heat-carrying particles. The waste heat recovery device is connected to the trough-type heat collection device 1 and is used to recover the heat energy that was not completely absorbed by the heat-carrying particles. The waste heat recovery device is also connected to the output end of the power fan 5 and / or the heat-using equipment and is used to preheat the conveying air and / or supply heat to the heat-using equipment.

[0042] Specifically, the trough-type solar collector 1 can collect solar energy and convert it into heat energy. The trough-type solar collector 1 has heat collection channels for the flow of a heat exchange medium. The heat exchange medium absorbs heat energy by exchanging heat with the medium as it flows through the heat collection channels. In this embodiment, the heat exchange medium uses heat-carrying particles, which, compared to heat transfer oil in traditional systems, can achieve higher operating temperatures, enabling the system to operate stably in a higher temperature range of 600℃ to 900℃.

[0043] Cold particle storage tank 4 and hot particle storage tank 2 are connected to the inlet and outlet ends of the heat collection channel, respectively, via a gas-solid transport pipeline 7. Cold particle storage tank 4 stores the heat-carrying particles to absorb heat energy, while hot particle storage tank 2 temporarily stores the heat-carrying particles after absorbing heat energy. A power fan 5 is connected to the outlet end of cold particle storage tank 4 to provide transport air, ensuring that the heat-carrying particles remain in a flowing state throughout the transport process. After the power fan 5 is turned on, the heat-carrying particles, under the action of the transport air, can flow from cold particle storage tank 4 along the gas-solid transport pipeline 7 into the heat collection channel. During the flow along the heat collection channel, they absorb heat energy and their temperature rises. Then, they flow out of the heat collection channel and enter the hot particle storage tank 2 for temporary storage. Thus, using heat-carrying particles as the heat medium, heat energy is collected and stored through gas-solid flow heat transfer.

[0044] The outlet of the hot pellet storage tank 2 is connected to the heat release device 3 via a pellet conveying pipe 8. The heat release device 3 is connected to the heat-using equipment. When the heat-carrying pellets that have absorbed heat energy enter the heat release device 3, they can release the absorbed heat, thereby providing heat to the heat-using equipment. In this embodiment, the heat-using equipment is a steam generator. The heat release device 3 can transfer heat to the steam generator to produce high-temperature steam. The steam quality is stable, ensuring the efficient utilization of steam in the factory.

[0045] The outlet of the heat release device 3 is connected to the cold particle storage tank 4 via the particle conveying pipe 8. After releasing heat, the temperature of the heat-carrying particles decreases, and they return to the cold particle storage tank 4 for continued participation in the next round of heat exchange, thus enabling recycling. Both the hot particle storage tank 2 and the cold particle storage tank 4 are equipped with exhaust structures to promptly discharge the gas that enters the storage tank along with the heat-carrying particles.

[0046] The waste heat recovery device is connected to the trough-type solar collector 1 to recover heat energy in the trough-type solar collector 1 that has not been fully absorbed by the heat-carrying particles. The output end of the heat recovery sleeve 62 can be connected to the output end of the power fan 5 via the heat exchanger 13, enabling preheating of the conveying air. This heat is transferred to the flowing heat-carrying particles, increasing their initial temperature before entering the trough-type solar collector 1, which in turn helps to increase the temperature of the heat-carrying particles in the heat release device 3, thus improving heating efficiency. Alternatively, the output end of the heat recovery sleeve 62 can be directly connected to the heat-using equipment to directly heat it. Therefore, the system not only recovers the residual heat in the trough-type solar collector 1 but also avoids energy waste caused by heat loss. Through this reuse of circulating heat energy, the overall system efficiency is greatly improved, and dependence on external energy sources is effectively reduced.

[0047] See Figure 3 In this embodiment, the trough-type heat collection device 1 includes a heat collection inner tube 101, a bottom support 102, and a concentrator 103. The concentrator 103 is installed at a certain angle on the bottom support 102 to maximize the collection of sunlight. The concave surface of the concentrator 103 faces the outer wall surface of the heat collection inner tube 101. The concentrator 103 can receive sunlight and concentrate the light to the heat collection inner tube 101 through reflection, thereby collecting solar energy and converting it into heat energy. The heat collection channel is formed inside the heat collection inner tube 101, which allows the heat-carrying particles to flow.

[0048] Optionally, in this embodiment, the waste heat recovery device includes a heat recovery sleeve 62 and a circulating fan 61. The heat recovery sleeve 62 is sleeved on the outer periphery of the inner heat collection tube 101 and is coaxial with the inner heat collection tube 101. The gap between the heat recovery sleeve 62 and the inner heat collection tube 101 forms a heat recovery channel. The circulating fan 61 is connected to the input end of the heat recovery sleeve 62 and is used to provide circulating air to the heat recovery channel. The circulating air flows through the heat recovery channel and exchanges heat with the inner heat collection tube 101, thereby realizing the recovery of waste heat from the inner heat collection tube 101.

[0049] Optionally, the number of inner heat collection tubes 101 is set to multiple, and the multiple inner heat collection tubes 101 are distributed in a two-dimensional array along a first direction and a second direction; the first direction is the axial direction of the inner heat collection tubes 101, and the second direction is the direction perpendicular to the axial direction of the inner heat collection tubes 101; along the first direction, multiple inner heat collection tubes 101 in the same column are connected in series sequentially through a gas-solid transport pipe 7; along the second direction, multiple columns of inner heat collection tubes 101 are connected in parallel through a gas-solid transport pipe 7. With the above arrangement, the inner heat collection tubes 101 are rationally arranged, which can improve the heat collection efficiency and reduce heat loss.

[0050] Correspondingly, the number and position of the heat recovery sleeves 62 are also arranged according to the heat collection inner tubes 101. In this embodiment, the circulating air in the waste heat recovery device adopts a single-stage air intake method. Along the first direction, multiple heat recovery sleeves 62 in the same column are connected in series through the circulating air duct 63; along the second direction, multiple columns of heat recovery sleeves 62 are connected in parallel through the circulating air duct 63. Please refer to [link / reference] for details. Figure 1 , Figure 1 The diagram illustrates a feasible distribution of the inner heat collection tubes 101. The inner heat collection tubes 101 are arranged in a 4-row × 3-column array, and the heat recovery sleeves 62 are also arranged in a 4-row × 3-column array, corresponding to the positions of the inner heat collection tubes 101. Four heat recovery sleeves 62 in the same column are connected in series via a circulating air duct 63, and the three columns of heat recovery sleeves 62 are connected in parallel via the circulating air duct 63. Through this arrangement, three parallel circulating air paths are formed in the waste heat recovery device. Each path corresponds to one column of inner heat collection tubes 101. Along the first direction, all three paths intake air from the heat recovery sleeve 62 corresponding to the bottom row of inner heat collection tubes 101 and exhaust air from the heat recovery sleeve 62 corresponding to the top row of inner heat collection tubes 101. Therefore, for a column of inner heat collection tubes 101 arranged along the first direction, the circulating air for recovering waste heat has only one intake point, which is a single-stage intake; similarly, the exhaust air has only one outlet point, which is a single-stage exhaust.

[0051] Optionally, the flow direction of the circulating air can be the same as or opposite to the flow direction of the heat-carrying particles in the inner tube 101 of the heat collector. In this embodiment, the same flow direction is used. Figure 4As shown, the left end of the inner heat collection tube 101 is the heat-carrying particle inlet A, and the right end of the inner heat collection tube 101 is the heat-carrying particle outlet B. The left end of the heat recovery sleeve 62 is the circulating air inlet C, and the right end of the heat recovery sleeve 62 is the circulating air outlet D. The flow direction of the circulating air is the same as the flow direction of the heat-carrying particles in the inner heat collection tube 101.

[0052] Optionally, the heat release device 3 includes any one of a fluidized bed, a moving bed, and a descending bed. In this embodiment, the heat release device 3 adopts the form of a fluidized bed, with an internal evaporation heat exchange tube bundle 9, which uses the heat of the heat-carrying particles to evaporate water into qualified quality steam.

[0053] Optionally, the heat-carrying particles include any one of alumina, quartz sand, and ceramic particles. In this embodiment, the heat-carrying particles are selected from high-temperature resistant materials such as quartz sand.

[0054] Optionally, the particle size of the heat-carrying particles is 0 μm to 120 μm. In this embodiment, the particle size range of the heat-carrying particles (quartz sand) is preferably 30 μm to 80 μm.

[0055] Optionally, the flow velocity of the heat-carrying particles in the inner heat-collecting tube 101 is 1.5 m / s to 6 m / s. In this embodiment, the flow velocity of the heat-carrying particles, quartz sand, in the trough-type heat collection device 1 is optimized to 3 m / s to ensure efficient absorption and transfer of heat within the limited length of the inner heat-collecting tube 101, while avoiding particle aggregation and overheating.

[0056] Optionally, the particle concentration of the heat-carrying particles flowing in the inner heat-collecting tube 101 is 100 kg / m³. 3 ~500kg / m 3 .

[0057] Optionally, the temperature of the heat-carrying particles after being heated by the trough-type heat collection device 1 is 350℃~900℃, preferably 750℃~800℃. In this embodiment, to ensure that the system can operate stably for a long time at a high temperature, the inner heat collection tube 101 is made of a high-temperature resistant material, and according to design requirements, the temperature of the inner heat collection tube 101 can be stably maintained at 750℃ to ensure sufficient heat energy accumulation.

[0058] Optionally, the diameter ratio of the inner heat collection tube 101 to the heat recovery sleeve 62 is 0.5 to 0.9.

[0059] Optionally, the velocity of the circulating air is 0.1 m / s to 1 m / s, preferably 0.2 m / s to 0.5 m / s.

[0060] Optionally, a heat-absorbing material is provided on the outer wall of the inner heat-collecting tube 101, which can enhance the absorption and transfer efficiency of solar thermal energy reflected by the concentrator 103.

[0061] Optionally, the heat particle storage tank 2, the heat release device 3, and the pipeline connecting the heat collection inner pipe 101 are all provided with heat insulation material to reduce heat loss.

[0062] Optionally, a regulating valve is installed on the particle conveying pipeline 8 to facilitate control of the conveying volume of heat-carrying particles between the hot particle storage tank 2, the heat release device 3, and the cold particle storage tank 4. In practical applications, to further ensure the smooth conveying of heat-carrying particles between the hot particle storage tank 2, the heat release device 3, and the cold particle storage tank 4, the hot particle storage tank 2, the heat release device 3, and the cold particle storage tank 4 are arranged with a certain height difference. The particle conveying pipeline 8 can be set at an incline, and with the regulating valve open, automatic conveying can be achieved by utilizing the gravity of the heat-carrying particles themselves.

[0063] The parabolic trough solar thermal system provided in this embodiment efficiently collects solar thermal energy during system operation. The heat-carrying particles are maintained within an operating temperature range of 750°C and release heat through the heat release device 3 to supply steam to the steam generator, thus meeting the steam demand of the factory. Simultaneously, excess heat from the parabolic trough collector 1 is recovered through a waste heat recovery device. This waste heat can be used to preheat the conveyor air and heat-carrying particles, or directly to heat the heating equipment, significantly improving the system's thermal energy utilization efficiency. Furthermore, the gas-solid flow heat transfer method allows for flexible adjustment of the heat load by regulating the conveyor air velocity and heat-carrying particle flow rate, enabling the system to effectively cope with different illumination conditions and ensuring a stable supply of steam to the entire factory.

[0064] Example 2

[0065] The parabolic trough solar thermal system provided in this embodiment is applied in a combined heat and power project, aiming to generate electricity from the heat energy provided by solar energy and to drive a generator set to generate electricity through steam.

[0066] See Figure 2 In this embodiment, the basic structure and arrangement of the trough-type heat collection device 1, the hot particle storage tank 2, the heat release device 3, and the cold particle storage tank 4 are the same as in Embodiment 1, and will not be described again here.

[0067] In this embodiment, the waste heat recovery device also includes a heat recovery sleeve 62 and a circulating fan 61. The heat recovery sleeve 62 is sleeved on the outer periphery of the inner heat collection tube 101 and is coaxial with the inner heat collection tube 101. The gap between the heat recovery sleeve 62 and the inner heat collection tube 101 forms a heat recovery channel. The circulating fan 61 is connected to the input end of the heat recovery sleeve 62 and is used to provide circulating air to the heat recovery channel. The circulating air flows through the heat recovery channel and exchanges heat with the inner heat collection tube 101, thereby realizing the recovery of waste heat from the inner heat collection tube 101. The number and position of the heat recovery sleeves 62 also correspond to those of the inner heat collection tubes 101.

[0068] The difference from Embodiment 1 is that in this embodiment, the circulating air in the waste heat recovery device adopts a multi-stage air intake method, such as... Figure 2 As shown, along the second direction, multiple heat recovery sleeves 62 in the same row are connected in parallel via pipelines; along the first direction, multiple rows of heat recovery sleeves 62 are connected in parallel via pipelines. Please refer to [link to details]. Figure 2 , Figure 2 The diagram illustrates a feasible distribution of the inner heat collection tubes 101. The inner heat collection tubes 101 are arranged in a 4-row × 3-column array, and the heat recovery sleeves 62 are also arranged in a 4-row × 3-column array, corresponding to the positions of the inner heat collection tubes 101. Three heat recovery sleeves 62 in the same row are connected in parallel via a circulating air duct 63, and the four rows of heat recovery sleeves 62 are connected in parallel via circulating air ducts 63. Through this arrangement, four sets of parallel circulating air path branches are formed in the waste heat recovery device. Each set of branches corresponds to one row of inner heat collection tubes 101, and each set of branches contains three parallel circulating air path branches, each corresponding to one of the three inner heat collection tubes 101 in the same row. Based on this, the four sets of branches can simultaneously draw air from the heat recovery sleeve 62 positions corresponding to each row of inner heat collection tubes 101. Therefore, for a row of inner heat collection tubes 101 arranged along the first direction, the circulating air for recovering waste heat has multiple air inlet positions, resulting in multi-stage air inlet. Similarly, the air outlet is also a multi-stage air outlet.

[0069] The temperature of the circulating air can be controlled at 280℃. Through multiple entry and exit channels, an efficient heat recovery and reuse path is established, reducing heat loss and maximizing the system's energy efficiency.

[0070] In this embodiment, the heat-carrying particles are made of alumina, which can operate stably within a temperature range of 800°C. By controlling the flow rate and temperature of the heat-carrying particles, it can be ensured that the particles can efficiently absorb heat energy and transfer it to the steam generator.

[0071] In this embodiment, the heat release device 3 adopts a fluidized bed form and is equipped with an evaporative heat exchange tube bundle 9. The heat released by the heat-carrying particles heats the water and converts it into high-temperature steam. This steam can not only meet the steam needs of the factory, but also drive a generator set to generate electricity through a steam turbine, forming a combined heat and power (CHP) effect. The steam temperature is stabilized at 600℃, which can meet the requirements of the generator set for steam pressure and temperature.

[0072] In this embodiment, the trough-type solar collector 1 collects solar energy and converts it into heat energy, heating the heat-carrying particles to 800°C. The heat-carrying particles release heat through the heat release device 3, generating high-temperature steam in the steam generator. This high-temperature steam drives a steam turbine to generate electricity. Under varying light intensity, the heat load can be flexibly adjusted by regulating the airflow rate and the flow rate of the heat-carrying particles, maintaining a stable power output. Compared to traditional combined heat and power (CHP) systems, this embodiment significantly reduces equipment costs, improves thermal efficiency, and effectively addresses changes in light intensity, ensuring efficient system operation under different weather conditions.

[0073] Example 3

[0074] The trough-type solar thermal system provided in this embodiment is used to provide high-temperature heat energy in a large chemical production base. The chemical plant requires a stable and continuous high-temperature heat source for multiple production processes, including high-temperature reactions, distillation, and drying. The trough-type solar thermal system provided in this embodiment serves as the core heat energy supply equipment for the plant, meeting daily production needs while also providing redundant heat to cope with emergencies.

[0075] In this embodiment, the basic structure and arrangement of the trough-type heat collection device 1, the hot particle storage tank 2, the heat release device 3, the cold particle storage tank 4, the power fan 5, and the waste heat recovery device can all be referred to in Embodiment 1 or Embodiment 2, and will not be repeated here.

[0076] In this embodiment, alumina particles are used as the heat-carrying particles, capable of reaching temperatures up to 900℃. The design of the inner heat-collecting tube 101 takes into account the high-temperature operating environment, therefore employing a high-temperature resistant coating and corrosion-resistant materials to ensure long-term efficient operation. The flow velocity of the heat-carrying particles is optimized and set at 4 m / s, ensuring sufficient heat absorption while preventing excessive particle wear. During the heat-carrying particle transport process, the particle concentration is maintained at 250 kg / m³ to ensure the stability of particle flow and efficient heat transfer.

[0077] In this embodiment, the thermal particle storage tank 2 is designed with a multi-layer insulation structure, which can effectively reduce heat loss.

[0078] Preferably, in this embodiment, an automatic temperature control system is configured for the hot particle storage tank 2 and the cold particle storage tank 4. The automatic temperature control system includes a temperature sensor and a control unit. The temperature sensor is installed inside the storage tank and can monitor the temperature of the heat-carrying particles inside the tank in real time. The control unit is connected to the temperature sensor and to a regulating valve on the particle conveying pipeline 8. It can receive the current temperature data sent by the temperature sensor and control the opening of the regulating valve according to the current temperature data, thereby regulating the conveying flow rate of the heat-carrying particles and ultimately regulating the temperature of the heat-carrying particles in the storage tank to the target temperature. In addition, the control unit can be connected to the power fan 5 and can adjust the conveying airflow speed according to the flow requirements of the heat-carrying particles. The control unit can also be connected to the circulating fan 61 to control the circulating airflow speed as needed.

[0079] In this embodiment, the heat release device 3 adopts a moving bed form to ensure that the heat-carrying particles are evenly distributed when releasing heat. The heat release device 3 is equipped with an evaporative heat exchange tube bundle 9, which can transfer heat to a water or steam generator to produce high-temperature steam. This steam can be used to drive a steam turbine in the plant or directly supplied to the production line for heating reactions.

[0080] In this embodiment, the trough-type solar collector 1 collects solar energy and converts it into heat energy, heating the heat-carrying particles to 900°C. The heat-carrying particles release heat through the heat release device 3, generating high-temperature steam in the steam generator. This high-temperature steam drives a steam turbine to generate electricity. Under varying light intensity, the system can flexibly adjust the heat load by regulating the conveyor wind speed and the flow rate of the heat-carrying particles, maintaining stable power output. Compared to traditional combined heat and power (CHP) systems, the system in this embodiment significantly reduces equipment costs, improves thermal efficiency, and effectively responds to changes in light intensity, ensuring efficient operation under different weather conditions.

[0081] The above three embodiments demonstrate the advantages and feasibility of the parabolic trough solar thermal system provided in this application in different industrial applications, and can achieve efficient solar thermal energy conversion and utilization.

[0082] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0083] It should also be noted that, in this document, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor should they be construed as indicating or implying relative importance. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. In the absence of further restrictions, an element defined by the phrase "includes a..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes the element.

[0084] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand this application, and the content of this specification should not be construed as a limitation of this application. Furthermore, for those skilled in the art, there will be different forms of changes in the specific implementation methods and application scope based on this application. It is neither necessary nor possible to exhaustively list all implementation methods here, and obvious changes or modifications derived therefrom are still within the protection scope of this application.

Claims

1. A trough-type solar thermal system, characterized in that, include: Trough-type solar collectors, hot pellet storage tanks, heat release devices, and cold pellet storage tanks; The cold particle storage tank stores heat-carrying particles. The trough-type solar collector has a heat-collecting channel. The inlet end of the heat-collecting channel is connected to the outlet end of the cold particle storage tank, and the outlet end of the heat-collecting channel is connected to the inlet end of the hot particle storage tank. The trough-type solar collector is used to collect solar energy and convert it into heat energy. The heat-carrying particles can flow along the heat-collecting channel and absorb heat energy. The hot particle storage tank is used to temporarily store the heat-carrying particles after absorbing heat energy. The inlet end of the heat release device is connected to the outlet end of the hot particle storage tank, and the outlet end of the heat release device is connected to the inlet end of the cold particle storage tank. The heat release device is connected to heat-using equipment and is used to release the heat energy absorbed by the heat-carrying particles to supply heat to the heat-using equipment. A power fan is connected to the outlet end of the cold particle storage tank to provide conveying air for the flow of the heat-carrying particles; A waste heat recovery device is connected to the trough-type heat collector and is used to recover the heat energy in the trough-type heat collector that is not completely absorbed by the heat-carrying particles; the waste heat recovery device is also connected to the output end of the power fan and / or the heat-using equipment and is used to preheat the conveying air and / or supply heat to the heat-using equipment. The trough-type solar collector includes a solar collector inner tube, and the solar collector channel is formed inside the solar collector inner tube; The waste heat recovery device includes: a heat recovery sleeve, which is sleeved on the outer periphery of the inner heat collection tube and coaxially arranged with the inner heat collection tube, and the gap between the heat recovery sleeve and the inner heat collection tube forms a heat recovery channel; and a circulating fan, which is connected to the input end of the heat recovery sleeve and is used to provide circulating air to the heat recovery channel, and the circulating air flows through the heat recovery channel and recovers the heat energy of the inner heat collection tube.

2. The trough-type solar thermal system according to claim 1, characterized in that: The number of heat collection inner tubes is set to multiple, and the multiple heat collection inner tubes are distributed in a two-dimensional array along a first direction and a second direction; along the first direction, multiple heat collection inner tubes in the same column are connected in series through pipelines; along the second direction, multiple columns of heat collection inner tubes are connected in parallel through pipelines.

3. The trough-type solar thermal system according to claim 2, characterized in that: The heat recovery sleeve is configured in a manner corresponding to the number and position of the heat collection inner tube; Along the first direction, multiple heat recovery sleeves in the same column are connected in series via pipelines; along the second direction, multiple columns of heat recovery sleeves are connected in parallel via pipelines.

4. The trough-type solar thermal system according to claim 2, characterized in that: The heat recovery sleeve is configured in a manner corresponding to the number and position of the heat collection inner tube; Along the second direction, multiple heat recovery sleeves in the same row are connected in parallel via pipelines; along the first direction, multiple rows of heat recovery sleeves are connected in parallel via pipelines.

5. The trough-type solar thermal system according to claim 1, characterized in that: The trough-type solar collector also includes a bottom support and a concentrating mirror. The concentrating mirror is mounted on the bottom support, with its concave surface facing the outer wall of the inner heat collection tube. The concentrating mirror is used to receive sunlight and focus the light onto the inner heat collection tube through reflection.

6. The trough-type solar thermal system according to claim 1, characterized in that: The diameter ratio of the inner heat collection tube to the heat recovery sleeve is 0.5 to 0.

9.

7. The trough-type solar thermal system according to claim 1, characterized in that: The heat release device includes any one of a fluidized bed, a moving bed, or a descending bed.

8. The trough-type solar thermal system according to claim 1, characterized in that: The heat-carrying particles include any one of alumina, quartz sand, and ceramic particles.

9. The trough-type solar thermal system according to claim 1, characterized in that: The outer wall of the inner heat collection tube is provided with heat-absorbing material.

Images