A molten salt recovery system

Abstract

The present application relates to the technical fields of molten salt recovery, in particular to a molten salt recovery system. The molten salt recovery system comprises a molten salt tank, the molten salt tank is connected with a rotary atomizer at the top of a molten salt cooling tower through a pipeline, and the top of the molten salt cooling tower is provided with a cooling air passage; the molten salt cooling tower is connected with a fine powder collector through a pipeline, and the air outlet of the fine powder collector is connected with an induced draft fan through a pipeline. Liquid molten salt in the molten salt tank is transported to the rotary atomizer, in the molten salt cooling tower, the liquid molten salt becomes molten salt droplets under the action of the rotary atomizer, and is cooled into solid fine powder by contacting with air, and enters the fine powder collector with air, and the solid fine powder is collected for subsequent disposal or recovery.

Description

Technical Field

[0001] This invention relates to the field of molten salt recovery technology, and in particular to a molten salt recovery system. Background Technology

[0002] New energy storage technologies currently under development include molten salt energy storage, liquid air energy storage, and compressed air energy storage. Among them, molten salt energy storage technology has broad development prospects due to its advantages such as low cost, high heat capacity, and safety.

[0003] Molten salt energy storage is currently widely used in new energy systems such as solar thermal power generation systems. It utilizes the energy storage characteristics of molten salt to convert solar thermal energy into the internal energy of molten salt for storage and release, realizing the spatial and temporal migration of energy and meeting the grid peak-shaving needs of renewable energy. Besides solar thermal, molten salt energy storage is also applied in heating, steam supply, and flexible retrofitting of thermal power units. It can be combined with existing coal-fired power plants to achieve deep peak shaving, frequency regulation, and external heat supply for coal-fired power plants while providing large-scale energy storage. When using molten salt for thermal storage in solar thermal power plants, a large amount of molten salt is required to ensure the storage duration; for a 100MW solar thermal power plant, approximately 30,000 tons of molten salt are needed.

[0004] In view of this, a molten salt recovery system for a decommissioned molten salt energy storage device is provided. Summary of the Invention

[0005] The purpose of this invention is to provide a molten salt recovery system that can process molten salt in decommissioned molten salt energy storage devices and convert the liquid molten salt into solid fine powder for easy subsequent disposal or recycling.

[0006] This invention provides a molten salt recovery system, including a molten salt tank, which is connected to a rotary atomizer at the top of a molten salt cooling tower via a pipe. The top of the molten salt cooling tower is provided with a cooling air channel. The outlet of the molten salt cooling tower is connected to a fine powder collector via a pipe, and the outlet of the fine powder collector is connected to an induced draft fan via a pipe.

[0007] Furthermore, a regenerator is provided between the molten salt cooling tower and the fine powder collector; the cooling air channel is connected to an air filter through a pipe, and the air filter is connected to the regenerator through a pipe; the air outlet of the cooling air channel is aligned with the spray direction of the rotating atomizer.

[0008] Furthermore, a flow guide component is provided at the air outlet of the cooling air channel, and the air outlet of the flow guide component is aligned with the spray direction of the rotating atomizer.

[0009] Furthermore, it also includes a hot air blowing device, which includes a guide tube. The rotary atomizer is provided with a protective shell, and the guide tube is provided outside the protective shell. The guide tube is connected to an air heater through a pipe, and the air heater is connected to the regenerator through a pipe. The hot air flow channel outlet formed between the guide tube and the protective shell surrounds the atomizing disc of the rotary atomizer.

[0010] Furthermore, a molten salt conditioning system and a molten salt filter are provided between the molten salt tank and the molten salt cooling tower.

[0011] Furthermore, the molten salt tank is equipped with a molten salt pump, which is connected to the molten salt conditioning system via a pipeline.

[0012] Furthermore, an air mixing cooler is provided on the pipe connecting the fine powder collector and the induced draft fan.

[0013] Furthermore, the material outlet of the molten salt cooling tower and the material outlet of the fine powder collector are both connected to a solid conveying device.

[0014] Furthermore, the fine powder collector is a bag filter or an electrostatic precipitator.

[0015] Furthermore, the induced draft fan is connected to an air exhaust device via a pipe.

[0016] In summary, the present invention has the following advantages:

[0017] The technical solution of this invention involves conveying liquid molten salt from a molten salt tank to a rotary atomizer at the top of a molten salt cooling tower. Under the action of the rotary atomizer, the liquid molten salt is transformed into molten salt droplets, which then come into contact with air in the cooling air channel and are cooled into solid fine powder. This solid fine powder is then collected by the air into a fine powder collector for subsequent disposal or recycling. The air separated by the fine powder collector is discharged by an induced draft fan. The induced draft fan ensures that the entire system is under a slight negative pressure, preventing environmental pollution caused by leakage of molten salt fine powder due to poor sealing. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1This is a process flow diagram of the molten salt recovery system in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the rotary atomizer in an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached drawings: 1-Molten salt tank, 2-Molten salt pump, 3-Molten salt cooling tower, 301-Cooling air duct, 302-Flow guide assembly, 4-Rotary atomizer, 401-Protective shell, 402-Flow guide tube, 403-Hot air inlet, 404-Atomizing disc, 405-Hot air outlet, 5-Air filter, 6-Fine powder collector, 7-Air mixing cooler, 8-Exhaust fan, 9-Air exhaust device, 10-Air heater, 11-Molten salt conditioning system, 12-Molten salt filter, 13-Regenerator. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Example

[0026] A molten salt recovery system includes a molten salt tank 1, a molten salt cooling tower 3, a rotary atomizer 4, an air filter 5, a fine powder collector 6, an air mixing cooler 7, and an induced draft fan 8. Figure 1 As shown.

[0027] A rotary atomizer 4 is installed on the top of the molten salt cooling tower 3, and the atomizing disc 404 of the rotary atomizer 4 is located inside the molten salt cooling tower 3. A molten salt pump 2 is installed on the molten salt tank 1, and the molten salt pump 2 is connected to the molten salt conditioning system 11 and the molten salt filter 12 in sequence through pipes. The material outlet of the molten salt filter 12 is connected to the material inlet of the rotary atomizer 4 through a pipe.

[0028] In this embodiment, the molten salt conditioning system 11 employs a screw feeder and a molten salt electric heater connected sequentially via pipelines. Liquid molten salt in the molten salt tank 1 is transported to the screw feeder via the molten salt pump 2. Other molten salt components are added to the screw feeder for mixing before being transported to the molten salt electric heater for thorough mixing. After mixing, the mixture is then transported to the molten salt filter 12, and after filtration, it enters the rotary atomizer 4. The molten salt conditioning system 11 allows for the addition of other molten salt components to the existing liquid molten salt according to the product's molten salt composition requirements, ensuring the overall molten salt meets the usage requirements. The molten salt filter 12 removes solid impurities from the molten salt system.

[0029] The top of the molten salt cooling tower 3 is equipped with a cooling air channel 301, which is connected to an air filter 5 via a pipe. To ensure the quality of the molten salt produced by the molten salt recovery system, the air entering the molten salt cooling tower 3 first passes through the air filter 5 to remove dust and other impurities. The outlet of the molten salt cooling tower 3 is connected to a regenerator 13 via a pipe, and the outlet of the regenerator 13 is connected to a fine powder collector 6 via a pipe. The regenerator 13 is connected to the air filter 5 via a pipe, and the air outlet of the regenerator 13 is connected to an air heater 10 via a pipe. The regenerator 13 is made of tubular metal or fluoroplastic material to recover heat from the high-temperature air at the outlet of the molten salt cooling tower 3, improving the energy efficiency of the system. The hot side of the regenerator 13 is the high-temperature air at the outlet of the molten salt cooling tower 3, and the cold side is the cold air filtered by the air filter 5. After heat exchange through the regenerator 13, the cold air is heated to 100~150℃, and then enters the air heater 10 to be heated to 200-250℃.

[0030] The outlet of the fine powder collector 6 is connected to the air mixing cooler 7 through a pipe, the air mixing cooler 7 is connected to the induced draft fan 8 through a pipe, and the induced draft fan 8 is connected to the air exhaust device 9 through a pipe.

[0031] An induced draft fan 8 is installed at the system outlet to maintain a slight negative pressure throughout the system, preventing environmental pollution caused by leakage of molten salt fine powder due to poor sealing. In this embodiment, the air mixing cooler 7 is a Venturi mixer. Through the action of the Venturi tube, cold air is automatically drawn into the air mixing cooler 7, mixed with the high-temperature flue gas from the outlet of the fine powder collector 6, and then introduced into the induced draft fan 8 after meeting emission standards.

[0032] In this embodiment, a flow guiding component 302 is installed at the air outlet at the bottom of the cooling air channel 301. The air outlet of the flow guiding component 302 is aligned with the spray direction of the rotating atomizer 4 to ensure that the sprayed molten salt droplets quickly turn into molten salt fine powder. The flow guiding component 302 can be a flow guiding plate or a flow guiding pipe as used in the prior art.

[0033] The rotating atomizing disc 404 of the rotary atomizer 4 rotates at 6000-15000 rpm, atomizing molten salt particles with a particle size of 30-100 micrometers. Under the high-speed rotation of the rotary atomizer 4, the liquid molten salt is transformed into extremely small molten salt droplets, which then come into contact with the air entering through the cooling air channel 301 and cool, becoming solid molten salt fine powder. To ensure that the molten salt does not solidify on the rotating atomizing disc 404 of the rotary atomizer 4, a hot air blowing device is fixedly installed on the outside of the rotary atomizer 4, such as... Figure 2 As shown, the hot air blowing device includes a guide tube 402. A protective shell 401 is fixed to the outside of the rotating atomizer 4. The guide tube 402 is fixedly installed on the outside of the protective shell 401. A hot air inlet 403 is provided at the upper part of the guide tube 402. The hot air inlet 403 is connected to the air heater 10 through a pipe. The hot air flow channel outlet 405 formed by the bottom of the guide tube 402 and the protective shell 401 surrounds the atomizing disc 404. Heated air enters the guide tube 402 through the hot air inlet 403 and comes out from the hot air flow channel outlet 405 formed between the protective shell 401 and the guide tube 402, surrounding the atomizing disc 404. This ensures that the hot air completely surrounds the atomizing disc 404, guaranteeing that the temperature of the atomizing disc 404 is higher than the solidification temperature of the molten salt, and preventing the atomizing disc 404 from directly contacting the cold air, which could cause the molten salt to condense and block the atomizing nozzle. The hot air blowing device avoids direct contact between high-temperature molten salt droplets and low-temperature air, preventing the formation of scale on the atomizing disc 404. At the same time, the heated air plays a premixing role, which is more conducive to the cooling and condensation of fine powders.

[0034] The material outlets at the bottom of the molten salt cooling tower 3 and the fine powder collector 6 are both connected to a solid conveying device. In this embodiment, the solid conveying device is a belt conveyor, but other types of conveying equipment can also be used. The solid conveying device is connected to the fine powder packaging process, transporting the solid fine powder in the molten salt cooling tower 3 and the fine powder collector 6 to the fine powder packaging process for packaging.

[0035] In this embodiment, the fine powder collector 6 is a bag filter or an electrostatic precipitator, and the air emission device 9 is a chimney.

[0036] The recovery process of the molten salt recovery system provided by this invention is as follows:

[0037] The liquid molten salt in the molten salt tank 1 of the decommissioned solar thermal power plant and molten salt energy storage device is transported to the molten salt conditioning system 11 via the molten salt pump 2. The liquid molten salt is conditioned according to product requirements and then transported to the molten salt filter 12. After filtration, it is transported to the rotary atomizer 4. Simultaneously, air heated by the air heater 10 surrounds the atomizing disc 404 of the rotary atomizer 4 through the hot air outlet 405 of the hot air blowing device to prevent the atomizing disc 404 from directly contacting the cold air and causing molten salt condensation and clogging of the atomizing nozzle. In the molten salt cooling tower 3, the liquid molten salt is transformed into molten salt droplets by the rotary atomizer 4 and comes into contact with the air entering from the cooling air channel 301, cooling it into solid molten salt fine powder. The solid molten salt fine powder in the molten salt cooling tower 3 flows with the air, and part of it... Fine powder is deposited at the bottom of the tower and transported to the fine powder packaging process via a solid conveying device. Another part enters the regenerator 13 with the high-temperature air, where it exchanges heat with the cold air entering the regenerator 13. The cooled gas enters the fine powder collector 6, and the heated cold air (heated to 100~150℃) enters the air heater 10 (heated to 200-250℃) to heat the atomizing disc 404. The molten salt fine powder is collected by the fine powder collector 6 and transported to the fine powder packaging process via the solid conveying device through the bottom hopper. The separated air enters the air mixing cooler 7. In the air mixing cooler 7, the high-temperature air from the molten salt cooling tower 3 and the fine powder collector 6 is mixed with the cold air to about 40℃ and then enters the induced draft fan 8, and is discharged from the system through the air exhaust device 9.

[0038] The molten salt processed and recovered by this system includes halides, nitrates, sulfates, or mixtures thereof, such as sodium nitrate, potassium nitrate, sodium nitrite, or mixtures thereof. This invention addresses the significant molten salt disposal needs arising from the decommissioning of solar thermal power plants and molten salt energy storage devices. The system processes large quantities of liquid molten salt, converting it into solid micro-powders of 30-100 micrometers, avoiding the formation of millimeter-sized molten salt particles. This facilitates subsequent disposal or recovery, greatly improving product quality and added value, and enabling large-scale reuse of molten salt.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A molten salt recovery system, characterized in that, It includes a molten salt tank (1), which is connected to a rotary atomizer (4) at the top of a molten salt cooling tower (3) via a pipe. The top of the molten salt cooling tower (3) is provided with a cooling air channel (301). The outlet of the molten salt cooling tower (3) is connected to a fine powder collector (6) via a pipe. The outlet of the fine powder collector (6) is connected to an induced draft fan (8) via a pipe. A regenerator (13) is provided between the molten salt cooling tower (3) and the fine powder collector (6); the cooling air channel (301) is connected to the air filter (5) through a pipe, and the air filter (5) is connected to the regenerator (13) through a pipe; the air outlet of the cooling air channel (301) is aligned with the spray direction of the rotating atomizer (4); It also includes a hot air blowing device, which includes a guide tube (402). The rotary atomizer (4) is provided with a protective shell (401) outside the protective shell (401). The guide tube (402) is provided outside the protective shell (401). The guide tube (402) is connected to the air heater (10) through a pipe. The air heater (10) is connected to the regenerator (13) through a pipe. The hot air flow channel outlet (405) formed between the guide tube (402) and the protective shell (401) surrounds the atomizing disc (404) of the rotary atomizer (4).

2. The molten salt recovery system according to claim 1, characterized in that, The cooling air channel (301) is provided with a flow guide assembly (302) at the air outlet, and the air outlet of the flow guide assembly (302) is aligned with the spray direction of the rotating atomizer (4).

3. The molten salt recovery system according to claim 1, characterized in that, A molten salt conditioning system (11) and a molten salt filter (12) are provided between the molten salt tank (1) and the molten salt cooling tower (3).

4. The molten salt recovery system according to claim 3, characterized in that, The molten salt tank (1) is equipped with a molten salt pump (2), which is connected to the molten salt conditioning system (11) via a pipeline.

5. The molten salt recovery system according to claim 1, characterized in that, An air mixing cooler (7) is provided on the pipe connecting the fine powder collector (6) and the induced draft fan (8).

6. The molten salt recovery system according to claim 1, characterized in that, The material outlets of the molten salt cooling tower (3) and the fine powder collector (6) are both connected to a solid conveying device.

7. The molten salt recovery system according to claim 1, characterized in that, The fine powder collector (6) is a bag filter or an electrostatic precipitator.

8. The molten salt recovery system according to claim 1, characterized in that, The induced draft fan (8) is connected to the air exhaust device (9) via a pipe.

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