Solar heat absorption screen control system and control method thereof

Abstract

The invention discloses a solar heat absorption screen control system and a control method thereof, and the system comprises a molten salt system which is configured to store and transport molten salt; the solar heat absorption screen is arranged in a light receiving area of at least one part of pipeline in the molten salt system and is configured to convert light energy into heat energy under a light condensation condition; the control module is configured to detect a real-time illumination condition and generate a corresponding control instruction according to the illumination condition; and the heat preservation adjusting module is operably arranged on the periphery of the solar heat absorption screen and is configured to selectively wrap or expose the solar heat absorption screen in response to the control instruction, so that heat preservation is conducted on the solar heat absorption screen under the condition of no light, and flowing of the fused salt in the pipeline is maintained. And through cooperation of dynamic heat preservation and intelligent control, the quick response capability and reliability of the system are improved. The heat preservation adjusting module can be automatically opened and closed according to illumination changes, heat loss in the absence of illumination is reduced, and the fused salt solidification risk caused by sudden temperature drop of the heat absorption screen is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar thermal utilization, in particular to a solar heat absorption screen control system and a control method thereof. BACKGROUND

[0002] A solar thermal power generation system generally uses a light focusing device to focus solar energy onto a heat absorption screen, which converts light energy into heat energy and stores and converts energy through a heat transfer fluid (such as molten salt). Molten salt is widely used as a heat transfer and storage medium due to its high boiling point and good thermal stability. However, the existing solar thermal power generation system has some inherent technical problems when dealing with changes in light.

[0003] At night or in the absence of light, the temperature of the heat absorption screen drops rapidly, causing the temperature of the molten salt in the pipe connected to it to drop below the freezing point, resulting in the freezing and blocking of the pipe. To prevent this phenomenon, the existing technology usually adopts a method of completely emptying the molten salt in the system, but this brings new problems. Daily emptying and refilling of molten salt not only causes energy waste but also increases the complexity of system operation. Before the system is restarted the next day, the pipe needs to be cleaned and preheated, which consumes time and energy and seriously affects the efficiency and economy of the system.

[0004] Another problem is the heat management of the heat absorption screen itself. The heat absorption screen becomes a heat sink in the absence of light, losing a large amount of heat energy through radiation and convection, while the existing system uses a fixed insulation structure that cannot flexibly adjust the insulation state when the light condition changes, resulting in slow temperature rise of the heat absorption screen at the beginning of light focusing, affecting the overall efficiency of the system. At the same time, the switching of the molten salt circulating pump and the pipe emptying mechanism are imperfect, and the residual molten salt is prone to freeze at local low points, increasing the maintenance cost of the system.

[0005] Therefore, the existing technology lacks an integrated solution that can dynamically adjust the insulation state and molten salt flow according to the light condition, resulting in slow system response, low energy efficiency and insufficient reliability. SUMMARY

[0006] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a solar heat absorption screen control system and a control method thereof to solve the problems of molten salt freezing, system restart difficulty and high energy consumption caused by changes in light in the prior art.

[0007] To solve the above problems, the technical solution adopted by the present application is as follows: In a first aspect, the present application provides a solar heat absorption screen control system, comprising: a molten salt system configured to store and transport molten salt; a solar heat absorption screen arranged in the light receiving area of at least a portion of the pipe of the molten salt system and configured to convert light energy into heat energy under light focusing conditions; a control module configured to detect real-time light conditions and generate corresponding control instructions according to the light conditions; a molten salt flow regulation module configured to regulate the flow of molten salt in the solar heat absorption screen and its related pipelines according to the control instructions to prevent solidification.

[0008] In some embodiments, the system further comprises, a heat preservation adjustment module operatively arranged around the solar heat absorption screen and configured to selectively wrap or expose the solar heat absorption screen in response to the control instructions to preserve heat of the solar heat absorption screen in the absence of light to prevent solidification of molten salt in the pipelines.

[0009] In some embodiments, the heat preservation adjustment module comprises at least two peripheral movable units that cover or expose the solar heat absorption screen through opening and closing movements.

[0010] In some embodiments, the heat preservation adjustment module comprises a mechanical arm unit corresponding to the peripheral movable units, and the mechanical arm unit is configured to control the peripheral movable units to open and close in response to the control instructions.

[0011] In some embodiments, the heat preservation adjustment module further comprises an inner tower movable module arranged inside or at the end of the solar heat absorption screen to block heat convection between the solar heat absorption screen and the inner air flow field.

[0012] In some embodiments, the inner tower movable module is a cover plate structure that can be opened and closed, and the cover plate structure is arranged at the inner end of the solar heat absorption screen to close the inner end of the solar heat absorption screen in the heat preservation state.

[0013] In some embodiments, the molten salt system comprises a molten salt pipeline, a high-temperature molten salt storage tank, and a first molten salt pump, the solar heat absorption screen covers at least a portion of the outer surface of the molten salt pipeline, the high-temperature molten salt storage tank is used to store high-temperature molten salt, and the first molten salt pump is used to control the medium transmission between the high-temperature molten salt storage tank and the molten salt pipeline.

[0014] In some embodiments, the molten salt system further comprises a low-temperature molten salt storage tank and a second molten salt pump, and the second molten salt pump is used to control the medium transmission between the low-temperature molten salt storage tank and the molten salt pipeline.

[0015] In some embodiments, the control module is configured to switch the operation of the first and second molten salt pumps when the light conditions change to meet: in the presence of light, the second molten salt pump is opened, the first molten salt pump is closed, and the low-temperature molten salt flows through the solar heat absorption screen for heating; In the absence of light, the first molten salt pump is opened and the second molten salt pump is closed, so that the high-temperature molten salt circulates in the pipeline.

[0016] In some embodiments, a salt-repellent tank, a first salt-repellent pipeline and a second salt-repellent pipeline are further included. The first salt-repellent pipeline connects the pipeline where the first molten salt pump is located to the salt-repellent tank, and the second salt-repellent pipeline connects the pipeline where the second molten salt pump is located to the salt-repellent tank, so as to empty the residual molten salt in the molten salt storage tank when the pump body is closed.

[0017] In the second aspect, a control method applied to the solar heat absorption screen control system is provided, and the control method comprises the following steps: Detecting real-time light conditions; When there is no light or the light intensity is lower than a first threshold value, generating a first instruction to control the heat preservation adjustment module to wrap the solar heat absorption screen to perform heat preservation, and / or to control the molten salt flow regulation module to control the molten salt flow of the molten salt system; When there is light or the light intensity is higher than a second threshold value, generating a second instruction to control the heat preservation adjustment module to expose the solar heat absorption screen to absorb light energy, and to transfer heat from the solar heat absorption screen to the molten salt of the molten salt system.

[0018] In some embodiments, when heat is transferred from the solar heat absorption screen to the molten salt of the molten salt system, the following steps are further included: Opening the second molten salt pump to transport the low-temperature molten salt in the low-temperature molten salt storage tank, so that the low-temperature molten salt exchanges heat with the solar heat absorption screen; Closing the first molten salt pump.

[0019] In some embodiments, after the second instruction is generated, the molten salt circulation path is adjusted to switch from high-temperature molten salt circulation to low-temperature molten salt circulation, so that the low-temperature molten salt flows through the solar heat absorption screen to be heated.

[0020] In some embodiments, when the molten salt circulation path is switched, the molten salt in the circulation branch corresponding to the molten salt storage tank that stops running is emptied.

[0021] In some embodiments, when the molten salt is emptied, the following steps are further included: When the first molten salt pump is closed, the first salt-repellent pipeline is opened; When the second molten salt pump is closed, the second salt-repellent pipeline is opened.

[0022] Compared with the prior art, the present application at least has the following beneficial effects: The application improves the rapid response capability and reliability of the system through the cooperation of dynamic heat preservation and intelligent control. The heat preservation adjustment module can be automatically opened and closed according to the change of light, reduces the heat loss in the absence of light, and avoids the risk of molten salt solidification caused by the sudden drop of the heat absorption screen temperature. The control module integrates environmental perception and adaptive algorithm, optimizes the molten salt flow path, ensures the continuous flow or timely emptying of molten salt in the pipeline, thereby reducing the probability of blockage; controls the heat preservation adjustment module to enter the heat preservation state and maintain the flow of molten salt in the absence of light to prevent solidification, and controls the heat preservation adjustment module to exit the heat preservation state and adjust the molten salt circulation path in the presence of light; At the same time, the cooperation of the tower inner movable module and the peripheral movable unit enhances the comprehensiveness of heat preservation, especially inhibits the heat convection loss inside the heat absorption screen. The overall scheme does not need to rely on a complex auxiliary heating system, and through the innovation of structure design and control logic, the system energy efficiency is improved and the maintenance cost is reduced, which is especially suitable for the intermittent light solar thermal power generation scene; The control module ensures the continuous flow of molten salt in the pipeline by real-time monitoring of environmental conditions and adjusting the molten salt flow path accordingly, effectively preventing molten salt solidification. Especially, low-temperature molten salt is used for circulation in the presence of light, fully utilizing solar energy for heating; high-temperature molten salt is used to maintain flow in the absence of light, delaying the cooling process by utilizing its high initial temperature. This intelligent molten salt path management significantly improves the anti-solidification capability of the system.

[0023] The application will be further described in detail below in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0025] Figure 1 FIG. 1 is a structural schematic diagram of a solar heat absorption screen control system in an embodiment.

[0026] Figure 2 FIG. 2 is a schematic diagram of the overall framework of a solar heat absorption screen control system in an embodiment.

[0027] Figure 3 FIG. 3 is a schematic diagram of the cooperation of a solar heat absorption screen and a heat preservation adjustment module in an embodiment.

[0028] Figure 4 FIG. 4 is a flow schematic diagram of a solar heat absorption screen control method in an embodiment. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of the present application.

[0030] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present application, when it is described that a specific device is located between a first device and a second device, there can be an intervening device between the specific device and the first device or the second device, or there can be no intervening device. When it is described that a specific device is connected to other devices, the specific device can be directly connected to the other devices without an intervening device, or can not be directly connected to the other devices with an intervening device.

[0032] Techniques, methods, and equipment known to those of ordinary skill in the relevant art can not be discussed in detail, but in appropriate cases, the techniques, methods, and equipment should be considered part of the specification.

[0033] Reference Figures 1 to 3 In a first aspect, the present embodiment provides a solar heat screen control system, comprising: A molten salt system configured to store and transport molten salt; A solar heat screen 10 arranged in the light receiving area of at least part of the pipeline in the molten salt system, configured to convert light energy into heat energy under concentrated light conditions; A control module configured to detect real-time light conditions and generate corresponding control instructions according to the light conditions; A molten salt flow control module that adjusts the flow of molten salt in the solar heat screen 10 and its related pipelines according to the control instructions to prevent solidification.

[0034] It should be noted that in the prior art, molten salt solidification is usually prevented by a single emptying strategy, and there is a lack of active and fine control of the molten salt flow state. The present embodiment solves the problem of extensive management of molten salt state in the traditional scheme by setting a special molten salt flow control module, specifically: The molten salt flow regulation module actively controls the flow rate, flow volume and even flow direction of the molten salt flowing through the solar heat absorption panel 10 and its related pipelines according to the control instruction by adjusting the pump speed, valve opening degree or molten salt flow path and the like. For example, when the real-time detected illumination condition is determined to be no illumination condition or the illumination intensity is lower than the first threshold value, a first instruction is generated because generally in this case the molten salt system is no longer put into operation of the power generation system, in order not to be emptied but to keep the molten salt in the molten salt system from solidifying, the embodiment adopts a dynamic flow mode, that is, the molten salt flow regulation module controls the heat dissipation state of the solar heat absorption panel 10 to reduce the external heat dissipation, and synchronously and continuously drives the molten salt, so that the molten salt does not generate heat loss when passing through the solar heat absorption panel 10, and even can be supplemented and improved. By managing the heat loss of the entire molten salt system, as long as the molten salt flow is maintained, it can be ensured that the molten salt does not solidify. Compared with the traditional on-off control, the dynamic regulation can more accurately maintain the molten salt in a safe flow state and avoid excessive energy consumption.

[0035] Preferably, after detecting the real-time illumination condition, when it is determined that there is no illumination condition or the illumination intensity is lower than the first threshold value, the temperature at a set position in the pipeline is further detected, and when the temperature is close to the solidification point, the flow rate is increased to prevent local stagnation, or the minimum flow rate is maintained in a specific section to avoid the formation of dead zones.

[0036] Preferably, the molten salt flow regulation module adopts a variable frequency pump to realize stepless speed regulation, or realizes accurate flow distribution through coordinated opening degree adjustment of multiple valves.

[0037] The technical advantage of the embodiment is that the control dimension of anti-solidification is improved from the simple binary choice of "heat preservation / non-heat preservation" or "flow / non-flow" to continuous and adaptive management of the flow state itself, so that a more optimal balance between anti-solidification reliability and energy consumption is achieved.

[0038] In combination Figure 1 , as an implementation mode, further comprising: The heat preservation adjustment module 20 is operatively arranged around the solar heat absorption panel 10 and is configured to selectively wrap or expose the solar heat absorption panel 10 in response to the control instruction to heat preserve the solar heat absorption panel 10 in the no-illumination condition to prevent the molten salt from solidifying in the pipeline.

[0039] Optionally, the heat preservation adjustment module 20 is an implementation mode of the molten salt flow regulation module, that is, the molten salt flow regulation module includes a driving module for molten salt flow and the heat preservation adjustment module 20 for molten salt heat preservation.

[0040] More specifically, relying solely on regulating the flow of molten salt may not be sufficient to offset heat dissipation to the environment in extreme environments or long periods of no light, and the anti-freezing effect is limited. By adding an actively movable thermal regulation module 20, a collaborative anti-freezing strategy of "internal flow control and external thermal regulation" is realized.

[0041] The thermal regulation module 20 dynamically adjusts its heat dissipation conditions by changing its wrapping area or tightness around the solar heat absorption screen 10. When heat absorption is needed (such as during the day), it is fully opened to ensure the concentration efficiency; when thermal insulation is needed (such as at night or on cloudy days), it is closed to significantly reduce convective and radiative heat dissipation. This adjustable concept of heat loss management for thermal insulation state is one of the key innovations of this embodiment, breaking the traditional design idea of fixed thermal insulation layer. In implementation, the wrapping and exposure actions can be achieved through various mechanical ways such as translation, rotation or folding. Its beneficial effect lies in that it directly deals with the freezing risk from the perspective of reducing heat loss, and forms a more solid anti-freezing defense line with flow regulation.

[0042] Preferably, the thermal regulation module 20 includes at least two peripheral movable units that cover or expose the solar heat absorption screen 10 through opening and closing movements. The overall thermal insulation structure is divided into multiple peripheral movable units that can move independently or cooperatively, realizing modular design. Each peripheral movable unit is combined into different opening and closing states through relative movement (such as split, sliding, louvered rotation, etc.) between them. This modular design has the advantage of enabling local control or gradient thermal insulation, with more precise control.

[0043] Preferably, the thermal regulation module 20 includes a mechanical arm unit 21 corresponding to the peripheral movable units, and the mechanical arm unit 21 is configured to control the peripheral movable units to open and close in response to control instructions. Using the mechanical arm unit 21 (which can be an industrial robot arm, a customized hydraulic or electric push rod mechanism, etc.) as the driving source gives the system high flexibility and control accuracy. The mechanical arm unit 21 can perform complex three-dimensional trajectory movements, thereby optimizing the opening and closing path of the peripheral movable units, ensuring the tightness of the seal, and avoiding interference during movement.

[0044] In addition, the mechanical arm unit 21 has position feedback, which facilitates closed-loop control of the control module to accurately control the opening and closing angle or sealing pressure. Compared with simple hinges or guide rail mechanisms, the mechanical arm solution, although more expensive, offers better performance and adaptability, especially for scenarios in large power stations where reliability is extremely important.

[0045] As an implementation, the thermal regulation module 20 also includes an inner tower movable module arranged inside or at the end of the solar heat absorption screen 10, for blocking the thermal convection between the solar heat absorption screen 10 and the inner air flow field.

[0046] It should be noted that the present embodiment further realizes that there is a very easy-to-overlook heat loss path in the inner side or end of the solar heat absorption screen 10. Because in the concentrated solar power tower system, the solar heat absorption screen 10 is installed on the top of the tower, and its inner side or end is often connected with the tower structure to form a channel with the air space in the tower. The air in the tower can flow due to the chimney effect, and can take away a large amount of heat from the inner side of the heat absorption screen. The tower inner movable module (such as a heat insulation baffle, a sealing skirt, etc.) acts when heat preservation is needed, and closes or reduces these channels to effectively block the forced or natural convection heat dissipation generated thereby. This targeted blocking of the “invisible” heat loss path further improves the heat management efficiency and perfects the heat preservation system. The tower inner movable module and the peripheral movable unit jointly reshape the solar heat absorption screen 10 and its associated pipelines from a passive, transient energy converter into an active, time-span integrated heat storage unit.

[0047] Further, there is a technical effect that in the case of no light or light intensity lower than the first threshold, since the molten salt system has accumulated a certain amount of heat in the early stage, at this time, through the action of the peripheral movable unit and the tower inner movable module, the solar heat absorption screen 10 is converted from a heat absorption state under light or strong light conditions to a heat storage state under no light or weak light conditions. In the long time span from night to day, the molten salt in the molten salt system also presents different relative heat states when flowing through the region of the solar heat absorption screen 10, and therefore it is necessary to manage the heat in time sequence, such as: In the initial stage of no light or weak light, although the molten salt system has stored high-temperature molten salt due to daytime operation, the heat absorption screen itself as a huge metal body exposed to the environment will quickly lose its own stored sensible heat through radiation and convection (especially the strong convection of the “chimney effect” formed by its inner side and the air in the tower). The rapid loss of this part of heat not only causes the temperature of the heat absorption screen body to drop sharply, but also accelerates the cooling of the pipelines in contact with it and the molten salt in the pipelines, greatly increasing the energy burden required to maintain the flow of the molten salt.

[0048] By the joint action of the movable module inside the tower and the peripheral activity unit, the inside end and the outside of the heat absorbing screen are closed, greatly inhibiting the convective heat transfer caused by air flow, and the heat insulation material adopted by the movable module itself also effectively reduces the radiation and conduction heat loss. This significantly reduces the heat dissipation rate of the heat absorbing screen body and the connected pipeline during no light, so that the heat absorbing screen-pipeline system can retain the heat (in the form of sensible heat) absorbed and stored during the light period for a longer time inside itself. At this time, the entire heat absorbing screen-pipeline system is no longer just a heat transfer component, but plays the role of a short-term heat storage body. It provides a pre-heated flow channel with a temperature higher than the ambient temperature for the molten salt flowing through it, greatly reducing the temperature drop of the molten salt during flow due to heat dissipation to the environment. The state can be further divided into: 1. High temperature maintenance stage (initial stage of no light) At the initial stage of night or overcast day, due to the closure of the heat preservation module, the sensible heat stored in the heat absorbing screen-pipeline system begins to release slowly. At this time, the high-temperature molten salt pumped from the high-temperature molten salt storage tank 30 and flowing through this area not only does not dissipate heat to the environment, but also may obtain a small amount of heat supplement from the heat absorbing screen and pipeline wall surface still having residual heat. At this time, the temperature difference between the molten salt flowing into and out of the area is very small, and the system efficiency is very high.

[0049] This stage makes the most of the thermal inertia of the system, realizes "free" heat preservation, and almost no additional energy (only pump power) is needed to maintain the molten salt temperature far above the freezing point.

[0050] 2. Medium temperature transition stage (mid-stage of no light) As time goes on, the sensible heat of the heat absorbing screen-pipeline system is gradually consumed, and its inner wall temperature begins to slowly drop. At this time, the high-temperature molten salt flowing through it begins to slightly dissipate heat to the pipe wall, but its heat dissipation rate is greatly delayed by the heat preservation module. After the molten salt flows through this area, a controllable and small temperature drop is produced.

[0051] This stage is the key period for preventing freezing. The role of the heat preservation module makes the cooling process of the molten salt extremely slow and smooth, leaving sufficient reaction time for system control. If the temperature sensor detects that the outlet temperature of the molten salt approaches the safety threshold, the control module can start fine tuning, such as slightly increasing the flow rate of the molten salt to enhance heat transfer, or starting a low-power auxiliary heating (equipped in some possible embodiments) to maintain the system in a safe state at a minimum energy cost.

[0052] 3. Low temperature freezing prevention stage (end of no light, before dawn) At the end of the lightless period, the ambient temperature is usually the lowest, and the sensible heat of the heat-adsorbing screen-pipe system has been largely released, so the temperature of its inner wall is further reduced. The temperature difference between the flowing molten salt and the pipe wall is reduced, and the heat dissipation rate is further reduced, but the temperature of the molten salt is close to the critical point that needs intervention.

[0053] Even at this stage, due to the effective heat preservation in the early stage, the core temperature of the molten salt may still be significantly higher than the freezing point. The value of the heat preservation module lies in that it reduces the heat required for replenishment at the most severe test (the lowest ambient temperature). The system may only need to invest a small amount of auxiliary energy in the last few hours to safely transition to sunrise. Without this heat preservation design, the system may need to start high-power auxiliary heating as early as midnight, which is a huge energy consumption.

[0054] Preferably, the movable module in the tower is a cover plate structure, which is arranged at the inner side end of the solar heat-adsorbing screen 10 and can close the inner side end of the solar heat-adsorbing screen 10 in the heat preservation state. The cover plate can tightly cover the opening or connecting gap on the inner side of the heat-adsorbing screen through translational, rotational or overturning movement in the heat preservation state. When the cover plate is closed, a continuous and mechanically strong isolation surface can be formed, which not only blocks the airflow but also has certain heat insulation capacity. The cover plate can be made of composite insulation material to simultaneously consider the structural strength and heat insulation performance.

[0055] In combination Figure 2 As an embodiment, the molten salt system comprises a molten salt pipe, a high-temperature molten salt storage tank 30 and a first molten salt pump 31, the solar heat-adsorbing screen 10 covers at least a part of the outer surface of the molten salt pipe, the high-temperature molten salt storage tank 30 is used to store high-temperature molten salt, and the first molten salt pump 31 is used to control the medium transmission between the high-temperature molten salt storage tank 30 and the molten salt pipe. The first molten salt pump 31 is arranged at the outlet of the high-temperature molten salt storage tank 30, the outlet of the first molten salt pump 31 is connected to the inlet of the solar heat-adsorbing screen 10, and the outlet of the solar heat-adsorbing screen 10 is connected to the inlet of the high-temperature molten salt storage tank 30 through a corresponding molten salt pipe to form a circulation. Therefore, under the action of the first molten salt pump 31, the molten salt in the high-temperature molten salt storage tank 30 can flow into the solar heat-adsorbing screen 10 through the molten salt pipe, and the molten salt in the solar heat-adsorbing screen 10 can also flow into the high-temperature molten salt storage tank 30 through the molten salt pipe, thereby realizing a basic circulation loop of molten salt flow control and solving the problems of basic flow power and heat source required for anti-freezing.

[0056] Further, the high-temperature molten salt storage tank 30 plays the role of "heat buffer" and "anti-condensation heat source" here. During the light-off period, the high-temperature molten salt stored therein (usually accumulated during the previous light period) is driven by the first molten salt pump 31 to circulate in the pipeline loop containing the solar heat absorption screen 10. The sensible heat carried by these molten salts can continuously heat the heat absorption screen and the pipeline to maintain their temperature above the freezing point. This basic loop is the core of the system to realize the "anti-condensation with heat" strategy. The technical idea is to cleverly use the heat energy stored by the system itself during operation to deal with the risk of shutdown period, realize the time transfer and self-sufficiency of energy, and reduce the dependence on additional auxiliary heating.

[0057] Preferably, the molten salt system further comprises a low-temperature molten salt storage tank 40 and a second molten salt pump 41 for controlling the medium transmission between the low-temperature molten salt storage tank 40 and the molten salt pipeline.

[0058] The low-temperature molten salt loop of the low-temperature molten salt storage tank 40 and the second molten salt pump 41, and the high-temperature molten salt loop of the high-temperature molten salt storage tank 30 and the first molten salt pump 31 in the previous embodiment form a double-loop system. The low-temperature molten salt loop is mainly used for system operation during sufficient light: the low-temperature molten salt flows through the heated heat absorption screen, absorbs heat to become high-temperature salt, and is transported to the high-temperature molten salt storage tank 30 for storage. The high-temperature molten salt loop is as above, mainly used for anti-condensation circulation during no light. This design decouples the heat absorption function and the anti-condensation function to some extent, allowing the system to intelligently switch to the optimal working mode according to the light conditions, so that each type of molten salt works efficiently within its temperature range, improving the overall system efficiency.

[0059] Further, the control module is configured to switch the operation of the first molten salt pump 31 and the second molten salt pump 41 when the light condition changes, so as to meet: Under light conditions, open the second molten salt pump 41 and close the first molten salt pump 31, so that the low-temperature molten salt flows through the solar heat absorption screen 10 for heating; Under no light conditions, open the first molten salt pump 31 and close the second molten salt pump 41, so that the high-temperature molten salt circulates in the pipeline.

[0060] The control logic of the control module is closely related to the core variable of the light condition. The purpose of "opening the second molten salt pump 41 and closing the first molten salt pump 31 under light conditions" is to make the system enter the "charging" mode, that is, to preferentially store the valuable solar energy into the high-temperature molten salt storage tank 30 through the heating of the low-temperature molten salt. "Opening the first molten salt pump 31 and closing the second molten salt pump 41 under no light conditions" is to start the "anti-condensation mode" and use the stored heat energy to maintain the system temperature. This mode decision based on the light state ensures that the system behavior always matches the current external energy condition, avoiding the invalid operation and waste of energy, which is the key to the efficient and automatic operation of the system.

[0061] As an implementation, it also includes a salt-bleeding tank 50, a first salt-bleeding pipeline 51 and a second salt-bleeding pipeline 52. The first salt-bleeding pipeline 51 connects the pipeline where the first molten salt pump 31 is located to the salt-bleeding tank 50, and the second salt-bleeding pipeline 52 connects the pipeline where the second molten salt pump 41 is located to the salt-bleeding tank 50, for emptying the residual molten salt in the molten salt storage tank when the pump body is closed. The emptying system composed of the salt-bleeding tank 50 and the two salt-bleeding pipelines solves the risk of solidification of the residual molten salt in the branch pipeline and the pump cavity due to stagnation when the molten salt pump is switched (for example, the first molten salt pump 31 is closed), specifically: At the same time or later than the pump closing instruction is issued, the control module opens the corresponding salt-bleeding pipeline valve. Due to the action of gravity or system residual pressure, the residual molten salt in the branch will be discharged through the salt-bleeding pipeline to the dedicated salt-bleeding tank 50. In this way, "shutdown emptying" is achieved, and the possibility of solidification of the static molten salt is fundamentally eliminated. The salt-bleeding tank 50 as a temporary receiving device can return the molten salt or handle it separately before the branch is started again. This emptying mechanism as a supplement and safety backup of the molten salt flow regulation greatly enhances the reliability of the system, especially in the case of frequent start-stop or sudden failure.

[0062] In combination with Figure 4 In a second aspect, the embodiment provides a control method of a solar heat absorption screen control system as described in the above embodiment, comprising: detecting real-time light conditions; generating a first instruction to control the heat preservation adjustment module 20 to wrap the solar heat absorption screen 10 for heat preservation and / or control the molten salt flow regulation module to control the molten salt flow of the molten salt system when there is no light or the light intensity is lower than a first threshold value; generating a second instruction to control the heat preservation adjustment module 20 to expose the solar heat absorption screen 10 to absorb light energy, and use the solar heat absorption screen 10 to transfer heat to the molten salt of the molten salt system when there is light or the light intensity is higher than a second threshold value.

[0063] Based on real-time lighting conditions, the heat preservation adjustment module 20 and the molten salt flow control module are cooperatively controlled, and the complex anti-solidification and efficient heat absorption problems are converted into response functions of the key state variable of the lighting conditions. When the light is lower than the threshold value (indicating insufficient energy input, and heat dissipation is dominant), the anti-solidification mode characterized by "heat preservation" and "flow maintenance" is triggered. When the light is higher than the threshold value (indicating sufficient energy input, and effective heating can be performed), the heat absorption mode characterized by "bare heat absorption" is triggered. It is worth noting that "and / or" is used in the instructions, which gives flexibility to the method, allowing a decision to be made whether to start only one measure or both measures simultaneously according to specific conditions (such as temperature drop rate). This preventive and cooperative control based on the state of external energy is more proactive and effective than traditional remedial control based on rear-end temperature feedback.

[0064] As an embodiment, when heat is transferred from the solar heat absorption screen 10 to the molten salt system, it includes: The second molten salt pump 41 is opened to transport the low-temperature molten salt in the low-temperature molten salt storage tank 40, so that the low-temperature molten salt exchanges heat with the solar heat absorption screen 10. The first molten salt pump 31 is closed.

[0065] In the heat absorption mode, the low-temperature molten salt circuit should be used for work. When the low-temperature molten salt contacts the high-temperature solar heat absorption screen 10, it has a larger heat transfer temperature difference, which means that it can absorb more heat and heat up faster in the same heat exchange area and time. At the same time, the high-temperature salt circuit (the first salt pump) is closed to avoid the ineffective circulation of high-temperature molten salt at this time, causing waste of heat energy and loss of pump power, and to ensure the rationality of the energy flow of the system.

[0066] As an embodiment, after the second instruction is generated, the molten salt circulation path is adjusted from high-temperature molten salt circulation to low-temperature molten salt circulation, so that the low-temperature molten salt flows through the solar heat absorption screen 10 to be heated.

[0067] The molten salt circulation path is not simply the start and stop of the pump, but also a series of orderly valve actions and pump start and stop timing control, to ensure that the low-temperature molten salt circulation is switched to under light or strong light.

[0068] Preferably, when the molten salt circulation path is switched, the molten salt in the circulation branch corresponding to the stopped molten salt storage tank is emptied to solve the long-term safety problem of the stopped equipment (pump, local pipeline and tank) during the switching process.

[0069] Because in the planned shutdown state, the residual molten salt is still a potential risk point. By forcibly adding the emptying step in the switching process, it is solidified as a standard operating procedure, which can actively and completely eliminate the risk and lay a foundation for the safe start or long-term standby of the next cycle of the system.

[0070] Specifically, when the molten salt is drained: When the first molten salt pump 31 is closed, the first salt drainage pipeline 51 is opened; when the control logic determines that the first molten salt pump 31 needs to be closed, an instruction to open the first salt drainage pipeline 51 is issued simultaneously or with a delay; When the second molten salt pump 41 is closed, the second salt drainage pipeline 52 is opened; when the control logic determines that the second molten salt pump 41 needs to be closed, an instruction to open the second salt drainage pipeline 52 is issued simultaneously or with a delay.

[0071] This interlocking logic eliminates the possibility of human error and automates and precisely controls the draining operation, which is an important detail for improving the automation level and safety of the system.

[0072] In summary, compared with the prior art, the above-mentioned embodiments have at least the following technical advantages: The present application improves the rapid response capability and reliability of the system through the cooperation of dynamic heat preservation and intelligent control. The heat preservation adjustment module 20 can be automatically opened and closed according to changes in light, reducing heat loss in the absence of light and avoiding the risk of molten salt solidification caused by a sudden drop in the temperature of the heat absorption screen. The control module integrates environmental perception and adaptive algorithms, optimizes the molten salt flow path, and ensures continuous flow or timely drainage of the molten salt in the pipeline, thereby reducing the probability of blockage; At the same time, the cooperation of the tower activity module and the peripheral activity unit enhances the comprehensiveness of heat preservation, especially inhibiting the heat convection loss on the inside of the heat absorption screen. The overall scheme does not rely on a complex auxiliary heating system, and through structural design and control logic innovation, it realizes the improvement of system energy efficiency and the reduction of maintenance cost, and is especially suitable for intermittent light solar thermal power generation scenarios; The control module ensures the continuous flow of molten salt in the pipeline by monitoring environmental conditions in real time and adjusting the molten salt flow path accordingly, effectively preventing molten salt solidification. In particular, low-temperature molten salt is used for circulation when there is light, making full use of solar energy for heating; high-temperature molten salt is used to maintain flow when there is no light, using its high initial temperature to delay the cooling process. This intelligent molten salt path management significantly improves the anti-solidification capability of the system.

[0073] The above-mentioned embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and substitutions made by those skilled in the art based on the present application are within the scope of protection claimed by the present application.

Claims

1. A solar thermal absorption screen control system, characterized in that, include: The molten salt system is configured for storing and transporting molten salt; A solar heat absorption screen, disposed in the light-receiving area of ​​at least a portion of the pipes in the molten salt system, is configured to convert light energy into heat energy under concentrated light conditions; The control module is configured to detect real-time lighting conditions and generate corresponding control commands based on those conditions. The molten salt flow control module regulates the flow of molten salt in the solar heat absorption screen and its related pipes according to the control command to prevent it from solidifying.

2. The solar heat absorption screen control system as described in claim 1, characterized in that, It also includes, A heat preservation and adjustment module is operably disposed around the solar heat absorption screen and is configured to selectively wrap or expose the solar heat absorption screen in response to the control command, so as to keep the solar heat absorption screen warm under no-light conditions to prevent molten salt from solidifying inside the pipe.

3. The solar heat absorption screen control system as described in claim 2, characterized in that, The heat preservation and adjustment module includes at least two peripheral moving units, which cover or expose the solar heat absorption screen through opening and closing movements.

4. The solar heat absorption screen control system as described in claim 3, characterized in that, The heat preservation and adjustment module includes a robotic arm unit, which is connected to a peripheral active unit. The robotic arm unit is configured to control the peripheral active unit to open and close in response to the control command.

5. A solar heat absorption screen control system as described in claim 2, characterized in that, The heat preservation and adjustment module also includes an in-tower movable module, which is located inside or at the end of the solar heat absorption screen to block the thermal convection between the solar heat absorption screen and the inner air flow field.

6. A solar heat absorption screen control system as described in claim 5, characterized in that, The movable module inside the tower is an openable and closable cover structure. The cover structure is arranged at the inner end of the solar heat absorption screen and can close the inner end of the solar heat absorption screen under heat preservation conditions.

7. A solar thermal absorption screen control system as described in any one of claims 1 to 6, characterized in that, The molten salt system includes a molten salt pipeline, a high-temperature molten salt storage tank, and a first molten salt pump. The solar heat absorption screen covers at least a portion of the outer surface of the molten salt pipeline. The high-temperature molten salt storage tank is used to store high-temperature molten salt, and the first molten salt pump is used to control the medium transfer between the high-temperature molten salt storage tank and the molten salt pipeline.

8. A solar heat absorption screen control system as described in claim 7, characterized in that, The molten salt system also includes a cryogenic molten salt storage tank and a second molten salt pump, the second molten salt pump being used to control the medium transfer between the cryogenic molten salt storage tank and the molten salt pipeline.

9. A solar heat absorption screen control system as described in claim 8, characterized in that, The control module is configured to switch the operation of the first molten salt pump and the second molten salt pump when the illumination conditions change, in order to satisfy: Under sunlight, turn on the second molten salt pump and turn off the first molten salt pump, so that the low-temperature molten salt flows through the solar heat absorption screen for heating; In the absence of light, turn on the first molten salt pump and turn off the second molten salt pump to circulate the high-temperature molten salt in the pipeline.

10. A solar heat absorption screen control system as described in claim 9, characterized in that, It also includes a salt-free tank, a first salt-free pipeline, and a second salt-free pipeline; The first salt-draining pipeline connects the pipeline where the first molten salt pump is located to the salt-draining tank, and the second salt-draining pipeline connects the pipeline where the second molten salt pump is located to the salt-draining tank, and is used to empty the residual molten salt in the molten salt storage tank when the pump body is turned off.

11. A control method for a solar thermal absorption screen control system as described in any one of claims 2 to 10, characterized in that, include: Detect real-time lighting conditions; When there is no light or the light intensity is below the first threshold, a first instruction is generated to control the heat preservation and adjustment module to wrap the solar heat absorption screen for heat preservation, and / or to control the molten salt flow regulation module to control the molten salt flow of the molten salt system. When there is light or the light intensity is higher than the second threshold, a second instruction is generated to control the exposed solar heat absorption screen of the heat preservation and regulation module to absorb light energy and use the solar heat absorption screen to transfer heat to the molten salt of the molten salt system.

12. The control method as described in claim 11, characterized in that, When using a solar thermal absorber to transfer heat to the molten salt in a molten salt system, the following steps are included: Turn on the second molten salt pump to transfer the low-temperature molten salt in the low-temperature molten salt storage tank, so that the low-temperature molten salt can exchange heat with the solar heat absorption screen; Shut down the first molten salt pump.

13. The control method as described in claim 12, characterized in that, After generating the second instruction, the molten salt circulation path is adjusted, switching from high-temperature molten salt circulation to low-temperature molten salt circulation, so that the low-temperature molten salt flows through the solar heat absorption screen and is heated.

14. The control method as described in claim 13, characterized in that, When switching molten salt circulation paths, the molten salt in the circulation branch corresponding to the stopped molten salt storage tank is emptied.

15. The control method as described in claim 14, characterized in that, During molten salt venting: When the first molten salt pump is shut down, the first desalination line is opened; When the second molten salt pump is shut down, open the second desalination line.

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