Salt dissolving system and method for heat storage system of high-altitude photo-thermal power station

Abstract

The invention provides a salt dissolving system and method for a heat storage system of a high-altitude photo-thermal power station. The system comprises a feeding system, a preheating system, a combustion system, a salt dissolving tank, a molten salt heating furnace, a hot salt tank and a control system. The feeding system is connected with the salt dissolving tank; the preheating system is arranged in the salt dissolving tank; the combustion system is connected with the salt dissolving tank; the molten salt heating furnace is connected with the salt dissolving tank; the hot salt tank is connected with the molten salt heating furnace; a first temperature measuring point is arranged in the salt dissolving tank, a second temperature measuring point is arranged in the hot salt tank, and the control system is used for controlling the amount of fused salt conveyed from the salt dissolving tank to the combustion system based on the first temperature measuring point and used for controlling the amount of fused salt conveyed from the salt dissolving tank to the fused salt heating furnace based on the temperature difference between the first temperature measuring point and the second temperature measuring point. According to the scheme, the construction requirements of continuous, stable and low-energy-consumption salt dissolving process of a photo-thermal power station in a high-altitude area can be met, fused salt condensation caused by too low environment temperature is prevented, and the insulating capacity is improved to cope with the problem of air resistance reduction caused by low air pressure.

Description

Technical Field

[0001] The present invention relates to the field of salt-forming technology for high-altitude solar thermal power stations, and in particular to a salt-forming system and method for a heat storage system of a high-altitude solar thermal power station. Background Art

[0002] The molten salt salting system is one of the key parts of a solar thermal power station. Its function is to convert solid molten salt into liquid high-temperature molten salt before entering the commissioning operation, and keep it in a molten state throughout the life of the power station. The existing molten salt salting storage system consists of a salting tank, a molten salt tank, and a conveying pipeline connecting the two. The solid powdered molten salt is first heated to a molten state in the salting tank, and then the high-temperature liquid molten salt is transported to the high-temperature molten salt tank through a conveying pipeline by a molten salt pump. However, in the actual working process, especially at the beginning of the molten salt salting, due to the limited heating space of the solid molten salt, a large amount of solid molten salt is difficult to melt synchronously, and the solid molten salt will continue to collapse during the melting process, causing solid-liquid separation. After that, there will be large pieces of solid molten salt floating above the high-temperature liquid molten salt or precipitated in the high-temperature liquid molten salt, which makes the molten salt unevenly heated, and it is difficult for the solid molten salt to further absorb heat and dissolve, which increases the electric heat consumption of the salt and reduces the salting rate. The solid molten salt may also block the conveying pipeline and reduce the working efficiency of the molten salt pump.

[0003] In addition, the molten salt system consumes a lot of energy to completely melt the solid molten salt into liquid molten salt, and in the process of transporting the high-temperature molten salt from the molten salt system to the molten salt storage system, due to the low temperature of the transmission pipeline, the high-temperature molten salt will lose heat during the transmission process, especially in cold areas such as the northwest, where the heat loss is greater, thus affecting the temperature stability of the heat storage molten salt. In the molten salt tank storing high-temperature liquid molten salt in the molten salt storage system of the prior art, as the storage time of the molten salt increases, the temperature of the liquid molten salt in the molten salt tank will gradually decrease, and it cannot provide a temperature-stable heat storage medium for the solar thermal power station.

[0004] On this basis, currently, there is only one solar thermal project under construction in the world with a construction area belonging to a high-altitude area (sea wave height exceeding 3500m), namely the Zabuye project in Tibet. However, as a large-scale, resource-rich, far-reaching, challenging, environmentally friendly, regionally focused, isolated grid-source-grid-load-storage project, the Zabuye project in Tibet has no project experience support. However, since the air in high-altitude areas also has the characteristics of low oxygen content and low air pressure, and the ambient temperature is extremely cold, the project is large in scale, and the molten salt transportation range is wide, especially the project trial operation is in winter, the impact of unfavorable factors such as low external air pressure and extremely low ambient temperature is increased. Therefore, how to ensure the stability, continuity and low energy consumption of the molten salt system of the solar thermal power station is an urgent problem to be solved. Summary of the invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a salt-forming system and method for the heat storage system of a high-altitude solar thermal power station, which can meet the construction requirements of continuous, stable and low-energy consumption of the salt-forming process of solar thermal power stations in high-altitude areas, prevent the condensation of molten salt due to excessively low ambient temperature, and improve the insulation capacity to cope with the problem of decreased air resistance caused by low air pressure.

[0006] The present invention provides a salt-forming system for a heat storage system of a high-altitude solar thermal power station, comprising a feeding system, a preheating system, a combustion system, a salt-forming tank, a molten salt heating furnace, a hot salt tank and a control system, wherein the control system is electrically connected to the feeding system, the preheating system, the combustion system, the salt-forming tank, the molten salt heating furnace and the hot salt tank respectively; The feeding system is connected to the salt-forming tank and is used to convey the solid molten salt into the salt-forming tank; The preheating system is built into the salt-forming tank, and is used to heat part / all of the solid molten salt transported into the salt-forming tank by the feeding system to a molten state, so as to obtain molten salt; The combustion system is connected to the salt-forming tank, and is used for exchanging heat between the molten salt transported by the salt-forming tank and the high-temperature flue gas generated by the combustion system to obtain a first high-temperature molten salt, and for transporting the first high-temperature molten salt to the salt-forming tank for heat exchange with the solid molten salt and / or the molten salt to obtain a second high-temperature molten salt. The molten salt heating furnace is connected to the salt-forming tank and is used to heat the second high-temperature molten salt transported by the salt-forming tank to obtain a third high-temperature molten salt; The hot salt tank is connected to the molten salt heating furnace and is used to store the third high-temperature molten salt transported by the molten salt heating furnace; A first temperature measuring point is provided in the salt-forming tank, a second temperature measuring point is provided in the hot salt tank, and the control system is used to control the amount of molten salt transported from the salt-forming tank to the combustion system based on the first temperature measuring point, and to control the amount of molten salt transported from the salt-forming tank to the molten salt heating furnace based on the temperature difference between the first temperature measuring point and the second temperature measuring point; Insulation materials are arranged on the outside of the connecting pipes between the combustion system and the salt-forming tank, between the salt-forming tank and the molten salt heating furnace, between the molten salt heating furnace and the hot salt tank, and inside the combustion system.

[0007] Further, the combustion system includes a molten salt furnace, an air preheater and a second fan, the hot air output end of the air preheater is connected to the first input end of the molten salt furnace, the second input end of the molten salt furnace is connected to the combustible gas, so that the hot air output by the air preheater can assist the combustion of the combustible gas to generate high-temperature flue gas, the molten salt input end of the molten salt furnace is connected to the salt-forming tank, so that the molten molten salt and the high-temperature flue gas are heat-exchanged to obtain the first high-temperature molten salt and medium-temperature flue gas, the molten salt output end of the molten salt furnace is connected to the salt-forming tank, the flue gas output end of the molten salt furnace is connected to the flue gas input end of the air preheater, the cold air input end of the air preheater is connected to the atmosphere, so that the cold air in the atmosphere is heat-exchanged with the medium-temperature flue gas to obtain the hot air and low-temperature flue gas, the flue gas output end of the air preheater is connected to the second fan, and the second fan is also connected to the atmosphere; Among them, the second fan adopts a plateau-type fan, and the matching motor of the second fan adopts a high-power motor.

[0008] Furthermore, it also includes a hot blast furnace, which is connected to the hot salt tank and is used to preheat the hot salt tank; Among them, the supporting fan of the hot blast furnace adopts a plateau-type fan, and the supporting motor adopts a high-power motor.

[0009] Furthermore, the salt-refining tank is provided with an exhaust pipe, the exhaust pipe is connected to the first fan, and a liquid level meter is provided in the salt-refining tank; Among them, the first fan adopts a plateau-type fan, and the matching motor of the first fan adopts a high-power motor.

[0010] Furthermore, a first molten salt pump, a second molten salt pump and a stirring device are also provided in the salt-forming tank. The first molten salt pump is connected to the molten salt furnace, and the second molten salt pump is connected to the molten salt heating furnace.

[0011] Furthermore, the preheating system includes at least one electric heater.

[0012] Furthermore, the feeding system includes a feeding place, an elevator, a feeding place and a buffer structure, the feeding place is a funnel-shaped structure, the feeding place is an inverted funnel-shaped structure, the lower end of the elevator is connected to the feeding place, and the upper end is connected to the feeding place, one end of the buffer structure is located in the feeding place, and the other end is connected to the feed port of the salt tank.

[0013] Furthermore, the feeding place is provided with a crushing device for crushing the granulated molten salt into powder.

[0014] Furthermore, it also includes a crushing device, which is connected to the feeding place and is used to crush the granulated molten salt into powder and then transport it to the feeding place.

[0015] The present invention also provides a salt-forming method for a heat storage system of a high-altitude solar thermal power station, which is applied to a salt-forming system for a heat storage system of a high-altitude solar thermal power station as described in any one of the above, and the method comprises: The feeding system transports the solid molten salt into the salt tank; The preheating system heats part / all of the solid molten salt in the salt tank to a molten state to obtain the molten salt; The salt tank transports the molten salt into the combustion system based on the first temperature measurement point; The combustion system exchanges heat between the molten salt and the high-temperature flue gas generated by the combustion system to obtain the first high-temperature molten salt; The combustion system transports the first high-temperature molten salt to the salt tank; The first high-temperature molten salt exchanges heat with the solid molten salt and / or the molten salt to obtain the second high-temperature molten salt; The salt-forming tank transports the second high-temperature molten salt to the molten salt heating furnace based on the temperature difference between the first temperature measuring point and the second temperature measuring point; The molten salt heating furnace heats the second high-temperature molten salt to obtain the third high-temperature molten salt; The molten salt heating furnace transports the third high-temperature molten salt into the hot salt tank; The hot salt tank stores the third high-temperature molten salt.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In view of the environmental characteristics of the 4,500-meter plateau area where the salt-making system operates and the challenges faced under low temperature conditions in winter, this invention proposes a set of optimized technical solutions for the salt-making system. By strengthening the ability to cope with low pressure, low temperature and continuous and stable operation under complex working conditions, the salt-making process can be operated efficiently, safely and reliably. The specific technical measures are summarized as follows: 1. Improved control logic to ensure continuous and stable operation in low-temperature environments: In response to the need for stable operation under extremely cold conditions on the plateau, the salt-forming system introduced two sets of negative feedback control logics: the first set of control logic uses the temperature measurement point feedback between the inner wall of the hot salt tank and the salt-forming tank and the control of the second molten salt pump to prevent the salt-forming tank from being overheated and causing excessive injection of high-temperature molten salt into the hot salt tank, thereby causing the hot salt tank to expand due to overheating and causing structural damage; the second set of control logic uses the temperature measurement point of the salt-forming tank and the feedback control of the first molten salt pump to automatically increase the flow rate of the first molten salt pump when the temperature of the salt-forming tank drops too low, and send more molten salt into the molten salt furnace for heating and then recirculate it to the salt-forming tank, thereby preventing the problem of molten salt crystallization and blockage in the tank due to insufficient salt-forming tank temperature.

[0017] 2. Technical measures to deal with low air pressure: In view of the problem of thin air and low external air pressure in plateau areas, the fan is equipped with plateau-specific equipment. This fan has been optimized to improve insulation performance and is specifically designed to resist the problem of decreased air resistance caused by low air pressure. In addition, the supporting motors are all high-power models to compensate for the impact of motor power reduction (reduced load capacity) under plateau conditions, ensuring that the fan and motor can provide sufficient power and operate reliably in high-altitude environments.

[0018] 3. Technical measures to deal with low temperature environment: In order to solve the problem that the extremely low ambient temperature in winter may cause molten salt to condense in the pipeline, an insulation layer is installed on the outside of all pipelines involving the flow of molten salt. The insulation design can effectively isolate the influence of the extremely cold environment on the cooling of the molten salt, and at the same time ensure that the flow temperature drop of the molten salt is controlled within a low range during operation, thereby avoiding the threat of molten salt condensation to the operation of the system. This improvement provides an important guarantee for low temperature conditions in winter.

[0019] In short, the beneficial effects of the present invention are as follows: (1) Improved system adaptability: By adopting plateau-specific fans and high-power motors, the problem of reduced equipment output efficiency caused by low air pressure in the plateau is effectively overcome, making the system more adaptable to the environment. Whether it is a thin air environment or complex electrical conditions, the equipment can operate safely and stably, providing complete protection for production in extreme environments.

[0020] (2) Enhanced cold resistance of the system: The design of the pipeline insulation layer successfully alleviated the impact of extreme cold weather on the fluidity of molten salt, ensuring that the molten salt always remains in a liquid state under low temperature conditions. By reducing the heat loss of the system and maintaining the stability of the temperature of the molten salt medium, it not only avoids the risk of possible blockage, but also extends the service life of the equipment.

[0021] (3) Ensures the structural strength and stability of the system: The first set of negative feedback control logic dynamically monitors and adjusts the flow rate of the second molten salt pump to strictly control the speed and amount of high-temperature molten salt entering the hot salt tank, so that the thermodynamic state of the hot salt tank within the expansion range can be controlled, effectively preventing damage to the container structure due to excessive thermal expansion, and ensuring the structural reliability of the system during long-term continuous operation.

[0022] (4) Strengthened the low temperature compensation capability of the system: The second set of negative feedback control logic automatically adjusts the flow rate and delivery rate of the molten salt pump according to the real-time temperature changes in the salt tank, and quickly increases the temperature of the circulating molten salt in the salt tank to ensure that the system as a whole remains within the effective working range. This dynamic compensation mechanism not only avoids freezing and blockage, but also effectively improves the continuity and efficiency of the production process in low temperature environments.

[0023] (5) Improved the intelligent operation and safety of the system: The two sets of negative feedback control logic complement each other, realizing a complete set of closed-loop feedback management from real-time monitoring to dynamic adjustment. The entire salt system can accurately identify different abnormal working conditions and quickly take automatic adjustment measures, which significantly reduces the difficulty of manual operation and the risk of misoperation, while ensuring a more intelligent and safe operation process.

[0024] (6) Helps achieve efficient and reliable production goals: Comprehensive technical improvement measures have greatly enhanced the adaptability of the salt system under special conditions (such as low pressure on the plateau and extreme low temperature in winter), thereby ensuring that the production equipment can operate stably and uninterruptedly 24 hours a day. This optimized design not only improves production efficiency, but also significantly reduces the risk of unplanned shutdowns or accidents caused by environmental factors, bringing obvious benefits from the perspective of economic benefits and maintenance costs.

[0025] In summary, this salt system effectively overcomes the adverse effects of low pressure in plateau areas and low temperatures in winter on the production process through reasonable equipment selection, improved insulation measures and innovative control logic design, and significantly improves the adaptability and reliability of the system in special environments. The multiple improvement measures proposed in this technical solution not only reflect the customized design concept for complex working conditions, but also have strong application and promotion value in similar technical fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 A schematic structural diagram of a salt system for a heat storage system of a high-altitude solar thermal power station provided in an embodiment of the present invention.

[0027] In the figure: 1. Loading point; 2. Elevator; 3. Feeding point; 4. Buffer structure; 5. Salt tank; 6. Electric heater; 7. Stirring device; 8. Exhaust pipe; 9. First fan; 10. First molten salt pump; 11. Second molten salt pump; 12. Molten salt furnace; 13. Air preheater; 14. Second fan; 15. Liquid level meter. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0029] Embodiment 1: See also Figure 1 , an embodiment of the present invention provides a salt-forming system for a heat storage system of a high-altitude solar thermal power station, including a feeding system, a preheating system, a combustion system, a salt-forming tank 5, a molten salt heating furnace, a hot salt tank and a control system, wherein the control system is electrically connected to the feeding system, the preheating system, the combustion system, the salt-forming tank 5, the molten salt heating furnace and the hot salt tank respectively; The feeding system is connected to the salt-forming tank 5 and is used to convey the solid molten salt into the salt-forming tank 5; The preheating system is built into the salt-forming tank 5 and is used to heat part / all of the solid molten salt transported into the salt-forming tank 5 by the feeding system to a molten state to obtain molten salt; The combustion system is connected to the salt-forming tank 5, and is used to exchange heat between the molten salt transported by the salt-forming tank 5 and the high-temperature flue gas generated by the combustion system to obtain a first high-temperature molten salt, and to transport the first high-temperature molten salt to the salt-forming tank 5 for heat exchange with solid molten salt and / or molten salt to obtain a second high-temperature molten salt; The molten salt heating furnace is connected to the salt-forming tank 5 and is used to heat the second high-temperature molten salt transported by the salt-forming tank 5 to obtain a third high-temperature molten salt; The hot salt tank is connected to the molten salt heating furnace and is used to store the third high-temperature molten salt delivered by the molten salt heating furnace; A first temperature measuring point is provided in the salt-forming tank 5, and a second temperature measuring point is provided in the hot salt tank. The control system is used to control the amount of molten salt delivered from the salt-forming tank 5 to the combustion system based on the first temperature measuring point, and to control the amount of molten salt delivered from the salt-forming tank 5 to the molten salt heating furnace based on the temperature difference between the first temperature measuring point and the second temperature measuring point; Insulation materials are arranged on the outside of the connecting pipes between the combustion system and the salt-forming tank 5, between the salt-forming tank 5 and the molten salt heating furnace, between the molten salt heating furnace and the hot salt tank, and inside the combustion system.

[0030] Specifically, corresponding temperature monitoring devices are provided at the first temperature measuring point and the second temperature measuring point; when the temperature in the salt-forming tank 5 is too low, that is, the temperature indicated by the first temperature measuring point is lower than the first preset threshold value, the control system increases the amount of molten salt transported from the salt-forming tank 5 to the combustion system, transports more molten salt to the combustion system for heating and circulates back to the salt-forming tank 5, to prevent the temperature of the salt-forming tank 5 from being too low and causing the molten salt in the tank to crystallize; when the temperature difference between the wall surface temperature of the hot salt tank and the temperature of the salt-forming tank 5 is too large (usually manifested as the temperature of the salt-forming tank 5 is too high), that is, the difference between the second temperature measuring point and the first temperature measuring point is lower than the second preset threshold value, the control system reduces the amount of molten salt transported from the salt-forming tank 5 to the molten salt heating furnace, and when the temperature difference exceeds the protection value, closes the molten salt transport pipeline from the salt-forming tank 5 to the molten salt heating furnace, to prevent excessive high-temperature molten salt from entering the hot salt tank excessively, causing the hot salt tank to expand excessively and cause structural damage; Regarding the selection of insulation materials, for core high-temperature molten salt transmission pipelines, aerogel + aluminum silicate fiber composite solutions are preferred, and for medium and low temperature auxiliary pipelines, rock wool, composite silicate or polyurethane foam are preferred as the main materials.

[0031] In a specific embodiment, the salt-making system for the heat storage system of a high-altitude solar thermal power station further includes a hot air furnace, which is connected to a hot salt tank and is used to preheat the hot salt tank; The combustion system includes a molten salt furnace 12, an air preheater 13 and a second fan 14, the hot air output end of the air preheater 13 is connected to the first input end of the molten salt furnace 12, the second input end of the molten salt furnace 12 is connected to the combustible gas, so that the hot air output by the air preheater 13 helps to burn the combustible gas to generate high-temperature flue gas, the molten salt input end of the molten salt furnace 12 is connected to the salt tank 5, so that the molten molten salt and the high-temperature flue gas are heat-exchanged to obtain the first high-temperature molten salt and medium-temperature flue gas, the molten salt output end of the molten salt furnace 12 is connected to the salt tank 5, the flue gas output end of the molten salt furnace 12 is connected to the flue gas input end of the air preheater 13, the cold air input end of the air preheater 13 is connected to the atmosphere, so that the cold air in the atmosphere is heat-exchanged with the medium-temperature flue gas to obtain hot air and low-temperature flue gas, the flue gas output end of the air preheater 13 is connected to the second fan 14, and the second fan 14 is also connected to the atmosphere; The salt tank 5 is provided with an exhaust pipe 8, which is connected to the first fan 9 for exhausting air to prevent the structure from being damaged by excessive pressure in the salt tank 5. The salt tank 5 is provided with a liquid level meter 15 for displaying the molten salt level in the salt tank 5. The salt tank 5 is also provided with a first molten salt pump 10, a second molten salt pump 11 and a stirring device 7. The first molten salt pump 10 is connected to the molten salt furnace 12, and the second molten salt pump 11 is connected to the molten salt heating furnace. The preheating system includes at least one electric heater 6; preferably, the preheating system includes a plurality of electric heaters 6, and the plurality of electric heaters 6 are evenly distributed; The feeding system includes a feeding place 1, an elevator 2, a feeding place 3 and a buffer structure 4. The feeding place 1 is a funnel-shaped structure, and the feeding place 3 is an inverted funnel-shaped structure. The lower end of the elevator 2 is connected to the feeding place 1, and the upper end is connected to the feeding place 3. One end of the buffer structure 4 is located in the feeding place 3, and the other end is connected to the feeding port of the salt tank 5; preferably, the buffer structure 4 is a trough-shaped structure; Among them, the first fan 9, the second fan 14, and the supporting fans of the hot air blower all adopt plateau-type fans, and the supporting motors of the first fan 9, the second fan 14, the first molten salt pump 10, the second molten salt pump 11, the hot air blower and other equipment all adopt high-power motors.

[0032] Specifically, the design parameters of the plateau type fan are as follows: Air volume (Q): 6000 – 25,000 m³ / h; Wind pressure (ΔP): 600 – 6000 Pa; Motor power (P): 0.6 – 65 kW; Operating temperature range: -40℃ to +60℃; Material and protection level: IP66 or higher; Noise level: ≤85 dB(A); Speed ​​(rpm): variable frequency speed regulation; Service life: ≥20 years; The design parameters of high power motors are as follows: Rated voltage (V): 380V – 10kV (with enhanced withstand voltage level); Power (kW): +15%-30% power margin based on standard power; Efficiency (η): >=IE3 / IE4 standard; Frequency (Hz): variable frequency speed regulation; Insulation class: F or H; Protection grade (IP): ≥IP65; Altitude applicable range (m): 3500m and above; Working temperature (℃): -40℃ to +50℃.

[0033] In an optional embodiment, the feeding place 1 is provided with a crushing device for crushing the granulated molten salt into powder.

[0034] In another optional embodiment, the feeding system further includes a crushing device, which is connected to the feeding place 1 and is used to crush the granulated molten salt into powder and then transport it to the feeding place 1.

[0035] Embodiment 2: The present invention further provides a salt-forming method for a heat storage system of a high-altitude solar thermal power station, which is applied to a salt-forming system for a heat storage system of a high-altitude solar thermal power station as described in Example 1, and the method comprises: The feeding system transports the solid molten salt to the salt tank 5; The preheating system heats part / all of the solid molten salt in the salt tank 5 to a molten state to obtain molten salt; The salt tank 5 transports the molten salt to the combustion system based on the first temperature measurement point; The combustion system exchanges heat between the molten salt and the high-temperature flue gas generated by the combustion system to obtain the first high-temperature molten salt; The combustion system transports the first high-temperature molten salt to the salt tank 5; The first high-temperature molten salt exchanges heat with the solid molten salt and / or the molten salt to obtain the second high-temperature molten salt; The salt tank 5 transports the second high-temperature molten salt to the molten salt heating furnace based on the temperature difference between the first temperature measuring point and the second temperature measuring point; The molten salt heating furnace heats the second high-temperature molten salt to obtain a third high-temperature molten salt; The molten salt heating furnace transports the third high-temperature molten salt to the hot salt tank; The hot salt tank stores the third highest temperature molten salt.

[0036] In a specific embodiment, the method comprises: The granulated molten salt is crushed into powder by a crushing device and then transported to the feeding place 1, or the granulated molten salt is crushed into powder by a crushing device in the feeding place 1; The powdered solid molten salt is lifted to a high position by the elevator 2; The powdered solid molten salt is transported to the salt tank 5 through the feeding place 3 and the buffer structure 4; The electric heater 6 heats part / all of the solid molten salt in the salt tank 5 to a molten state to obtain molten salt; The salt-forming tank 5 transports the molten salt to the molten salt furnace 12 through the molten salt input end of the molten salt furnace 12, and controls the transport speed based on the temperature monitored by the first temperature measuring point. When the temperature indicated by the first temperature measuring point is lower than the first preset threshold value, the control system increases the amount of molten salt transported from the salt-forming tank 5 to the molten salt furnace 12; at the same time, hot air is input to the first input end of the molten salt furnace 12, and combustible gas is input to the second input end, so that the hot air assists the combustion of the combustible gas to generate high-temperature flue gas; wherein the hot air is obtained by heat exchange between the cold air entering the air preheater 13 and the medium-temperature flue gas output by the molten salt furnace 12, and the low-temperature flue gas after heat exchange is discharged through the second fan 14; The molten salt furnace 12 exchanges heat between the molten salt and the high-temperature flue gas generated by itself to obtain a first high-temperature molten salt; The molten salt furnace 12 transports the first high-temperature molten salt to the salt tank 5; The first high-temperature molten salt exchanges heat with the solid molten salt and / or the molten salt to obtain the second high-temperature molten salt; The salt-forming tank 5 transports the second high-temperature molten salt to the molten salt heating furnace, and controls the transport speed based on the temperature difference between the second temperature measuring point and the first temperature measuring point. When the difference between the second temperature measuring point and the first temperature measuring point is lower than the second preset threshold, the control system reduces the amount of molten salt transported from the salt-forming tank 5 to the molten salt heating furnace, and closes the molten salt transport pipeline transporting from the salt-forming tank 5 to the molten salt heating furnace when the temperature difference exceeds the protection value; The molten salt heating furnace heats the second high-temperature molten salt to obtain a third high-temperature molten salt; The molten salt heating furnace transports the third high-temperature molten salt to the hot salt tank; The hot salt tank stores the third highest temperature molten salt.

[0037] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be arbitrarily combined with each other.

Claims

1. A salt-removing system for a heat storage system of a high-altitude solar thermal power station, characterized in that: It comprises a feeding system, a preheating system, a combustion system, a salt-forming tank (5), a molten salt heating furnace, a hot salt tank and a control system, wherein the control system is electrically connected to the feeding system, the preheating system, the combustion system, the salt-forming tank (5), the molten salt heating furnace and the hot salt tank respectively; The feeding system is connected to the salt-forming tank (5) and is used to convey solid molten salt into the salt-forming tank (5); The preheating system is built into the salt-forming tank (5) and is used to heat part / all of the solid molten salt transported into the salt-forming tank (5) by the feeding system to a molten state, so as to obtain molten salt; The combustion system is connected to the salt-forming tank (5) and is used for exchanging heat between the molten salt transported by the salt-forming tank (5) and the high-temperature flue gas generated by the combustion system to obtain a first high-temperature molten salt, and for transporting the first high-temperature molten salt to the salt-forming tank (5) to exchange heat with the solid molten salt and / or the molten salt to obtain a second high-temperature molten salt; The molten salt heating furnace is connected to the salt-forming tank (5) and is used to heat the second high-temperature molten salt transported by the salt-forming tank (5) to obtain a third high-temperature molten salt; The hot salt tank is connected to the molten salt heating furnace and is used to store the third high-temperature molten salt transported by the molten salt heating furnace; A first temperature measuring point is provided in the salt-forming tank (5), a second temperature measuring point is provided in the hot salt tank, and the control system is used to control the amount of molten salt transported from the salt-forming tank (5) to the combustion system based on the first temperature measuring point, and to control the amount of molten salt transported from the salt-forming tank (5) to the molten salt heating furnace based on the temperature difference between the first temperature measuring point and the second temperature measuring point; Insulation materials are provided on the outside of the connecting pipes between the combustion system and the salt-forming tank (5), between the salt-forming tank (5) and the molten salt heating furnace, between the molten salt heating furnace and the hot salt tank, and inside the combustion system.

2. The salt-removing system for a heat storage system of a high-altitude solar thermal power station according to claim 1, characterized in that: The combustion system comprises a molten salt furnace (12), an air preheater (13) and a second fan (14); the hot air output end of the air preheater (13) is connected to the first input end of the molten salt furnace (12); the second input end of the molten salt furnace (12) is connected to the combustible gas, so that the hot air output by the air preheater (13) assists the combustion of the combustible gas to generate high-temperature flue gas; the molten salt input end of the molten salt furnace (12) is connected to the salt tank (5), so that the molten salt exchanges heat with the high-temperature flue gas to obtain the a first high-temperature molten salt and a medium-temperature flue gas, wherein the molten salt output end of the molten salt furnace (12) is connected to the salt tank (5), the flue gas output end of the molten salt furnace (12) is connected to the flue gas input end of the air preheater (13), the cold air input end of the air preheater (13) is connected to the atmosphere, so that the cold air in the atmosphere exchanges heat with the medium-temperature flue gas to obtain the hot air and the low-temperature flue gas, the flue gas output end of the air preheater (13) is connected to the second fan (14), and the second fan (14) is also connected to the atmosphere; The second fan (14) is a plateau-type fan, and the matching motor of the second fan (14) is a high-power motor.

3. The salt-removing system for a heat storage system of a high-altitude solar thermal power station according to claim 1 or 2, characterized in that: It also includes a hot blast furnace, which is connected to the hot salt tank and is used to preheat the hot salt tank; Among them, the supporting fan of the hot blast furnace adopts a plateau-type fan, and the supporting motor adopts a high-power motor.

4. The salt-removing system for a heat storage system of a high-altitude CSP power station according to claim 2, characterized in that: The salt-removing tank (5) is provided with an exhaust pipe (8), the exhaust pipe (8) is connected to a first fan (9), and a liquid level meter (15) is provided in the salt-removing tank (5); The first fan (9) is a plateau-type fan, and the motor matched with the first fan (9) is a high-power motor.

5. The salt-removing system for a heat storage system of a high-altitude CSP power station according to claim 4, characterized in that: A first molten salt pump (10), a second molten salt pump (11) and a stirring device (7) are also provided in the salt-forming tank (5); the first molten salt pump (10) is connected to the molten salt furnace (12); and the second molten salt pump (11) is connected to the molten salt heating furnace.

6. The salt-removing system for a heat storage system of a high-altitude solar thermal power station according to claim 1, characterized in that: The preheating system comprises at least one electric heater (6).

7. The salt-removing system for a heat storage system of a high-altitude solar thermal power station according to claim 1, characterized in that: The feeding system comprises a feeding place (1), an elevator (2), a feeding place (3) and a buffer structure (4); the feeding place (1) is a funnel-shaped structure, the feeding place (3) is an inverted funnel-shaped structure, the lower end of the elevator (2) is connected to the feeding place (1), and the upper end is connected to the feeding place (3); one end of the buffer structure (4) is located in the feeding place (3), and the other end is connected to the feed port of the salt tank (5).

8. The salt-removing system for a heat storage system of a high-altitude solar thermal power station according to claim 7, characterized in that: The feeding point (1) is provided with a crushing device for crushing the granulated molten salt into powder.

9. The salt-removing system for a heat storage system of a high-altitude solar thermal power station according to claim 7, characterized in that: It also includes a crushing device, which is connected to the feeding place (1) and is used to crush the granulated molten salt into powder and then transport it to the feeding place (1).

10. A salt-forming method for a heat storage system of a high-altitude solar thermal power station, applied to a salt-forming system for a heat storage system of a high-altitude solar thermal power station as claimed in any one of claims 1 to 9, characterized in that: The method comprises: The feeding system transports the solid molten salt into the salt-forming tank (5); The preheating system heats part / all of the solid molten salt in the salt-forming tank (5) to a molten state, so as to obtain the molten salt; The salt tank (5) transports the molten salt into the combustion system based on the first temperature measurement point; The combustion system exchanges heat between the molten salt and the high-temperature flue gas generated by the combustion system to obtain the first high-temperature molten salt; The combustion system transports the first high-temperature molten salt to the salt-forming tank (5); The first high-temperature molten salt exchanges heat with the solid molten salt and / or the molten salt to obtain the second high-temperature molten salt; The salt-forming tank (5) transports the second high-temperature molten salt to the molten salt heating furnace based on the temperature difference between the first temperature measuring point and the second temperature measuring point; The molten salt heating furnace heats the second high-temperature molten salt to obtain the third high-temperature molten salt; The molten salt heating furnace transports the third high-temperature molten salt into the hot salt tank; The hot salt tank stores the third high-temperature molten salt.

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