Fluidized bed direct salt dissolution system utilizing solar energy, and working method thereof

Abstract

Provided are a fluidized bed direct salt dissolution system utilizing solar energy, and a working method thereof. During sunlight hours, a solar thermal collector mirror field (13) concentrates, by means of tracking and control, a large portion of solar energy into a solar fluidized bed (14) for direct salt dissolving, and a small portion of solar energy is concentrated into a heat accumulator (10) and is converted into thermal energy and stored in a heat storage material; and during non-sunlight hours, the thermal energy stored in the heat storage material is used to preheat a gas, and an electric heating device (15) in the solar fluidized bed (14) is started to realize continuous salt dissolution. By using solar energy to directly heat fluidized molten salt particles for salt dissolution, energy transmission links are simplified, the energy transfer efficiency is improved, and the high-efficiency utilization of solar energy is achieved.

Description

A fluidized bed direct salting system utilizing solar energy and its working method Technical Field

[0001] The present invention relates to the technical field of molten salt energy storage, and in particular to a fluidized bed direct salting system utilizing solar energy and a working method thereof. Background Art

[0002] Solar energy utilization is often affected by factors such as weather, geography, and season, limiting the stability and continuity of energy systems. However, solar thermal power generation can utilize physical and chemical methods for low-cost heat storage, achieving peak load shifting and ensuring stable power generation system performance. Therefore, it has the potential to serve as a baseload or peak-shaving unit. Liquid molten salt, with its high stability and good fluidity, is currently widely used as a heat transfer and storage medium for solar thermal power generation and power system peak shaving.

[0003] Molten salt is solid at room temperature and generally has a high melting point, so it needs to be heated before use. Current molten salt systems are mainly divided into molten salt electric heaters and gas-fired molten salt furnaces, depending on the heating method. However, using these solutions for salt formation requires additional electricity or fuel, resulting in high energy consumption and high salt formation costs. A small number of salt formation systems that use solar energy also first convert solar energy into thermal energy of a heat transfer fluid, which is then used to heat the molten salt to achieve salt formation. The excessive number of energy transfer and conversion links and devices results in low energy utilization and poor economic efficiency of the salt formation system.

[0004] Summary of the Invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, embodiments of the present invention provide a fluidized bed direct salt treatment system utilizing solar energy and a working method thereof.

[0007] In one aspect, the present invention provides a fluidized bed direct salt treatment system utilizing solar energy, comprising:

[0008] A solar fluidized bed, wherein an electric heating device is provided inside the solar fluidized bed and a thermometer is provided at the outlet end of the solar fluidized bed;

[0009] a molten salt particle fluidization chamber disposed upstream of the solar fluidized bed;

[0010] A solid-liquid-gas separation device is provided downstream of the solar fluidized bed, wherein the liquid phase outlet of the solid-liquid-gas separation device is connected to the liquid molten salt storage tank, the gas phase outlet of the solid-liquid-gas separation device is connected to the molten salt particle preheater, and the solid phase outlet of the solid-liquid-gas separation device is connected to the molten salt particle fluidization chamber;

[0011] A heat accumulator, wherein the outlet end of the heat accumulator is connected to the molten salt particle fluidization chamber, and a solar thermal collector field provides solar radiation energy to the heat accumulator and the solar fluidized bed;

[0012] The molten salt particle preheater, the particle outlet end of the molten salt particle preheater is connected to the molten salt particle fluidization chamber, a fan is arranged on the gas outlet pipeline of the molten salt particle preheater, and the fan outlet end is connected to the heat accumulator and the molten salt particle fluidization chamber respectively through pipelines.

[0013] In some embodiments, a flow controller is provided at the outlet end of the blower, and the outlet end of the flow controller is connected to the heat accumulator and the molten salt particle fluidization chamber through pipelines.

[0014] In some embodiments, a regulating valve and an air port are provided on the branch pipeline between the molten salt particle preheater and the fan.

[0015] In some embodiments, the flow controller is electrically connected to the thermometer and the regulating valve, and the flow controller adjusts the opening of the regulating valve according to the reading of the thermometer.

[0016] In some embodiments, a molten salt particle storage tank is further included, and the outlet end of the molten salt particle storage tank is connected to the particle inlet end of the molten salt particle preheater.

[0017] In some embodiments, the solar thermal collector field focuses incident solar energy onto the solar fluidized bed and the heat accumulator through tracking and regulation, utilizes solar salt in the solar fluidized bed, and converts solar energy into thermal energy for storage in the heat accumulator.

[0018] In some embodiments, the heat accumulator is filled with phase change heat storage material or thermochemical heat storage material, and the surface of the heat accumulator is wrapped with thermal insulation material.

[0019] In some embodiments, the solid-liquid-gas separation device is a cyclone separator.

[0020] In some embodiments, the molten salt particle preheater is a hybrid structure.

[0021] On the other hand, the present invention provides a method for operating a fluidized bed direct salt treatment system utilizing solar energy, comprising the following steps:

[0022] When there is sufficient sunlight, the electric heating device is turned off, and the fan drives air into the molten salt particle fluidization chamber, blowing the molten salt particles into the solar fluidized bed to absorb solar radiation energy and liquefy; the solar collector field collects part of the solar energy into the heat storage tank and converts it into thermal energy for storage;

[0023] When there is insufficient sunlight, the solar collector field is turned off and the electric heating device is turned on. The fan drives the air into the heat storage tank to be heated into high-temperature air. The high-temperature air enters the molten salt particle fluidization chamber and blows the molten salt particles into the solar fluidized bed to absorb the heat energy provided by the electric heating device and liquefy.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention realizes direct solar heating of fluidized molten salt particles for salt formation, simplifies the energy transmission link, improves energy transmission efficiency, and realizes efficient utilization of solar energy.

[0026] The arrangement of the molten salt particle preheater, heat accumulator and electric heating device in the present invention can not only significantly improve the energy utilization rate of the salt-forming system and effectively reduce the operating cost of the salt-forming system, but also achieve long-term continuous operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0028] FIG1 is a schematic diagram of a fluidized bed direct salting system utilizing solar energy according to the present invention;

[0029] Description of reference numerals:

[0030] Molten salt particle storage tank 1, first valve 2, molten salt particle preheater 3, air port 4, second valve 5, fan 6, third valve 7, flow controller 8, fourth valve 9, heat accumulator 10, fifth valve 11, molten salt particle fluidization chamber 12, solar collector mirror field 13, solar fluidized bed 14, electric heating device 15, solid-liquid-gas separation device 16, sixth valve 17, seventh valve 18, liquid molten salt storage tank 19, eighth valve 20. DETAILED DESCRIPTION

[0031] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0032] The following describes a fluidized bed direct salt treatment system utilizing solar energy and its working method according to an embodiment of the present invention with reference to the accompanying drawings.

[0033] As shown in Figure 1, the fluidized bed direct salting system using solar energy of the present invention includes a solar fluidized bed 14, an electric heating device 15, a molten salt particle fluidizing chamber 12, a solid-liquid-gas separation device 16, a solar thermal collector field 13, a heat accumulator 10, a molten salt particle preheater 3, a liquid molten salt storage tank 19 and a molten salt particle storage tank 1.

[0034] An electric heating device 15 is installed within the solar fluidized bed 14. This allows for direct utilization of solar-generated salt. When sufficient sunlight is available, the salt is converted to salt; when insufficient sunlight is available, the electric heating device 15 heats the salt. The installation of the electric heating device 15 within the solar fluidized bed 14 ensures continuous and stable operation of the system, whether in the presence or absence of sunlight. A thermometer is installed at the outlet of the solar fluidized bed 14 to measure the temperature at the outlet.

[0035] The solid-liquid-gas separation device 16 is disposed downstream of the solar fluidized bed 14, and the outlet of the solar fluidized bed 14 is connected to the inlet of the solid-liquid-gas separation device 16. The solid-liquid-gas separation device 16 has three different outlets, namely, a gas phase outlet, a liquid phase outlet, and a solid phase outlet. The gas phase outlet of the solid-liquid-gas separation device 16 is connected to the gas inlet of the molten salt particle preheater 3 via an eighth valve 20, the liquid phase outlet of the solid-liquid-gas separation device 16 is connected to the inlet of the liquid molten salt storage tank 19 via a seventh valve 18, and the solid phase outlet of the solid-liquid-gas separation device 16 is connected to the inlet of the molten salt particle fluidization chamber 12 via a sixth valve 17.

[0036] The solid-liquid-gas separation device 16 is a hydrocyclone separator, which realizes gas separation through density difference and pressure difference, and realizes separation of solid and liquid through centrifugal force.

[0037] The molten salt particle fluidization chamber 12 is arranged upstream of the solar fluidized bed 14 , and the outlet end of the molten salt particle fluidization chamber 12 is connected to the inlet end of the solar fluidized bed 14 . The molten salt particles form a fluidized state in the molten salt particle fluidization chamber 12 and then enter the solar fluidized bed 14 .

[0038] The outlet of the heat accumulator 10 is connected to a molten salt particle fluidization chamber 12. The heat accumulator 10 is filled with a phase-change thermal storage material or a thermochemical thermal storage material. The surface of the heat accumulator 10 is coated with an insulating material, enabling long-term heat storage. This heat can also be used to preheat the molten salt particles when solar energy is insufficient, reducing electricity consumption. A solar collector field 13 provides solar radiation energy to the heat accumulator 10 and the solar fluidized bed 14. The solar collector field 13 focuses incident solar energy onto the solar fluidized bed 14 and the heat accumulator 10 through tracking and regulation. The solar energy is then converted into thermal energy for storage in the heat accumulator 10 using the solar-induced salt in the solar fluidized bed 14. During periods of sunlight, the solar thermal collector field 13 collects most of the solar energy into the solar fluidized bed 14 for direct salt formation through tracking and regulation, and collects a small amount of solar energy into the heat storage tank 10 and converts it into heat energy stored in the heat storage material. During periods of no sunlight, the heat energy stored in the heat storage material is used to preheat the gas, and the electric heating device 15 in the solar fluidized bed 14 is turned on to achieve continuous salt formation.

[0039] The molten salt particle storage tank 1 is used to store molten salt particles. The outlet end of the molten salt particle storage tank 1 is connected to the particle inlet end of the molten salt particle preheater 3 through a first valve 2.

[0040] The molten salt particle preheater 3 has two outlets, namely a particle outlet and a gas outlet. The particle outlet of the molten salt particle preheater 3 is connected to the molten salt particle fluidization chamber 12 via a third valve 7. After the high-temperature gas flowing out of the gas phase outlet of the solid-liquid-gas separation device 16 exchanges heat with the molten salt particles in the molten salt particle preheater 3, the molten salt particles are preheated. The preheated molten salt particles enter the molten salt particle fluidization chamber 12 from the particle outlet of the molten salt particle preheater 3. A fan 6 is provided on the gas outlet pipeline of the molten salt particle preheater 3. A flow controller 8 is provided on the outlet end of the fan 6. The outlet end of the flow controller 8 is connected to the heat accumulator 10 and the molten salt particle fluidization chamber 12 via pipelines. A fourth valve 9 is provided on the pipeline between the flow controller 8 and the heat accumulator 10, and a fifth valve 11 is provided on the pipeline between the flow controller 8 and the molten salt particle fluidization chamber 12. A regulating valve and a gas port 4 are provided on the branch line between the molten salt particle preheater 3 and the fan 6. Exhaust and replenishment of air are performed through the gas port 4. The regulating valve is the second valve 5. A flow controller 8 is electrically connected to the thermometer and the regulating valve. The flow controller 8 adjusts the opening of the regulating valve based on the thermometer reading, thereby actively regulating the flow of molten salt entering the solar fluidized bed 14.

[0041] The molten salt particle preheater 3 adopts a hybrid structure to achieve sufficient gas-solid heat exchange and efficient waste heat recovery, thereby reducing the energy consumption of the device.

[0042] The working method of the fluidized bed direct salting system using solar energy includes the following steps: when there is sufficient sunlight, the electric heating device 15 is turned off, the fan 6 drives air into the molten salt particle fluidization chamber 12, blows the molten salt particles into the solar fluidized bed 14 to absorb solar radiation energy and liquefy; the solar thermal collector field 13 collects part of the solar energy into the heat storage tank 10 and converts it into thermal energy for storage;

[0043] When there is insufficient sunlight, the solar thermal collector field 13 is turned off and the electric heating device 15 is turned on. The fan 6 drives the air into the heat accumulator 10 to be heated into high-temperature air. The high-temperature air enters the molten salt particle fluidization chamber 12 and blows the molten salt particles into the solar fluidized bed 14 to absorb the heat energy provided by the electric heating device 15 and liquefy.

[0044] The specific operating modes when there is sufficient sunlight are as follows:

[0045] The fifth valve 11 is opened, the fourth valve 9 and the electric heating device 15 are closed, and the other valves remain open. The fan 6 drives the air through the flow controller 8 and the fifth valve 11 and then enters the molten salt particle fluidization chamber 12, blowing the molten salt particles from the molten salt particle preheater 3 and the solid-liquid-gas separation device 16 to form a fluidized state and then enter the solar fluidized bed 14; in the solar fluidized bed 14, the molten salt particles absorb the solar radiation energy from the solar collector field 13 and liquefy to form a solid-liquid-gas three-phase flow containing solid molten salt particles, liquid molten salt and high-temperature air;

[0046] At the same time, the solar collector field 13 collects part of the solar energy into the heat storage tank 10 and converts it into thermal energy for storage;

[0047] After the three-phase flow from the solar fluidized bed 14 passes through the solid-liquid-gas separation device 16, the high-temperature gas enters the molten salt particle preheater 3 through the eighth valve 20, and the liquid molten salt enters the liquid molten salt storage tank 19 through the seventh valve 18. The high-temperature molten salt particles return to the molten salt particle fluidization chamber 12 after passing through the sixth valve 17; the high-temperature gas entering the molten salt particle preheater 3 is mixed with the molten salt particles from the molten salt particle storage tank 1 for heat exchange, and the gas enters the fan 6; then the above process is repeated to achieve continuous salting. Among them, the flow controller 8 can adjust the switch of the second valve 5, and the air flow entering the molten salt particle fluidization chamber 12 can be adjusted through the air port 4, thereby adjusting the flow of molten salt particles entering the solar fluidized bed 14, and realizing variable operating condition control.

[0048] The specific operating modes when there is insufficient light are:

[0049] The solar thermal collector field 13 stops working, the fifth valve 11 is closed, the fourth valve 9 and the electric heating device 15 are opened, and the other valves remain open. The fan 6 drives the air through the flow controller 8 and the valve 9 and enters the heat accumulator 10, where the air is heated to high-temperature air. The high-temperature air enters the molten salt particle fluidization chamber 12, blowing and heating the molten salt particles from the molten salt particle preheater 3 and the solid-liquid-gas separation device 16, and then enters the solar fluidized bed 14 after being fluidized.

[0050] In the solar fluidized bed 14, the molten salt particles absorb the heat energy provided by the electric heating device 15 and liquefy, forming a solid-liquid-gas three-phase flow containing solid molten salt particles, liquid molten salt and high-temperature air, which then enters the solid-liquid-gas separation device 16; the three phases are separated in the solid-liquid-gas separation device 16, wherein the high-temperature air enters the molten salt particle preheater 3 through the eighth valve 20, the liquid molten salt enters the liquid molten salt storage tank 19 through the seventh valve 18, and the high-temperature molten salt particles return to the molten salt particle fluidization chamber 12 after passing through the sixth valve 17;

[0051] After the high-temperature gas entering the molten salt particle preheater 3 mixes with the molten salt particles from the molten salt particle storage tank 1 for heat exchange, the gas enters the fan 6. The above process is then repeated to achieve continuous salting. The flow rate of gas entering the molten salt particle fluidization chamber 12 can be controlled by the flow controller 8, the second valve 5, and the gas port 4, thereby regulating the flow rate of molten salt particles entering the solar fluidized bed 14, achieving variable operating mode control.

[0052] In addition, since the heat accumulator 10 can preheat the molten salt particles to a high temperature, the power consumption of the electric heating device 15 can be greatly reduced, thereby reducing the energy consumption of the system.

[0053] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms may be directed to different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are mutually inconsistent.

[0054] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0055] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A fluidized bed direct salting system utilizing solar energy, characterized in that: include: A solar fluidized bed, wherein an electric heating device is provided inside the solar fluidized bed and a thermometer is provided at the outlet end of the solar fluidized bed; a molten salt particle fluidization chamber disposed upstream of the solar fluidized bed; A solid-liquid-gas separation device is provided downstream of the solar fluidized bed, wherein the liquid phase outlet of the solid-liquid-gas separation device is connected to the liquid molten salt storage tank, the gas phase outlet of the solid-liquid-gas separation device is connected to the molten salt particle preheater, and the solid phase outlet of the solid-liquid-gas separation device is connected to the molten salt particle fluidization chamber; A heat accumulator, wherein the outlet end of the heat accumulator is connected to the molten salt particle fluidization chamber, and a solar thermal collector field provides solar radiation energy to the heat accumulator and the solar fluidized bed; The molten salt particle preheater, the particle outlet end of the molten salt particle preheater is connected to the molten salt particle fluidization chamber, a fan is arranged on the gas outlet pipeline of the molten salt particle preheater, and the fan outlet end is connected to the heat accumulator and the molten salt particle fluidization chamber respectively through pipelines.

2. The system according to claim 1, wherein A flow controller is provided at the outlet end of the blower, and the outlet end of the flow controller is connected to the heat accumulator and the molten salt particle fluidization chamber through pipelines.

3. The system according to claim 2, wherein: A regulating valve and an air port are provided on the branch pipeline between the molten salt particle preheater and the fan.

4. The system according to claim 3, wherein: The flow controller is electrically connected to the thermometer and the regulating valve, and the flow controller adjusts the opening of the regulating valve according to the reading of the thermometer.

5. The system according to claim 1, wherein: It also includes a molten salt particle storage tank, the outlet end of which is connected to the particle inlet end of the molten salt particle preheater.

6. The system according to claim 1, wherein: The solar thermal collector field focuses incident solar energy onto the solar fluidized bed and the heat accumulator through tracking and regulation, utilizes solar salt in the solar fluidized bed, and converts solar energy into thermal energy for storage in the heat accumulator.

7. The system according to claim 6, wherein: The heat accumulator is filled with phase change heat storage material or thermochemical heat storage material, and the surface of the heat accumulator is wrapped with heat insulation material.

8. The system according to claim 1, wherein: The solid-liquid-gas separation device is a hydrocyclone separator.

9. The system according to claim 1, wherein: The molten salt particle preheater is a hybrid structure.

10. A method for operating a fluidized bed direct salt treatment system utilizing solar energy, characterized in that: Utilizing the system according to any one of claims 1 to 9, comprising the following steps: When there is sufficient sunlight, the electric heating device is turned off, and the fan drives air into the molten salt particle fluidization chamber, blowing the molten salt particles into the solar fluidized bed to absorb solar radiation energy and liquefy; the solar collector field collects part of the solar energy into the heat storage tank and converts it into thermal energy for storage; When there is insufficient sunlight, the solar collector field is turned off and the electric heating device is turned on. The fan drives the air into the heat storage tank to be heated into high-temperature air. The high-temperature air enters the molten salt particle fluidization chamber and blows the molten salt particles into the solar fluidized bed to absorb the heat energy provided by the electric heating device and liquefy.

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