An on-line fused salt cooling solidification sampler and sampling method

Abstract

The application belongs to the technical field of molten salt energy storage and heat transfer, and relates to an online molten salt cooling and solidification sampler and a sampling method. The upper end of a sampling branch pipe is connected with a molten salt conveying main pipe, and the lower end outlet is connected with a solidification core mold. A sampling valve is arranged at the inlet of the solidification core mold. A cooling sleeve is arranged outside the solidification core mold. An annular cooling channel is formed between the outer side wall of the solidification core mold and the inner side wall of the cooling sleeve. The cooling sleeve is axially sequentially provided with a cooling medium inlet and a cooling medium outlet, forming a closed sampling passage, so that the sampling process is isolated from the external atmosphere, avoiding the absorption of moisture, oxidation or decomposition of the high-temperature molten salt during the sampling process due to contact with air, avoiding sample distortion, and the solidification core mold is used as a receiving and forming container for the molten salt. The annular cooling channel is used to introduce the cooling medium, the internal molten salt is forcibly cooled, the salt ingot after each solidification has a consistent volume shape and cooling rate, the comparability of the analysis results is ensured, and the molten salt is prevented from being blocked due to the stagnation and solidification in the sampling branch.

Description

Technical Field

[0001] This invention belongs to the field of molten salt energy storage and heat transfer technology, and relates to an online molten salt cooling and solidification sampler and sampling method. Background Technology

[0002] In solar thermal power generation and large-scale molten salt thermal storage systems, nitrate-based molten salts (such as solar salt, with a mass ratio of approximately 60% sodium nitrate + 40% potassium nitrate) or chloride-based molten salts are used as heat transfer and storage media, operating in a long-term cycle at high temperatures of approximately 290–565°C. Due to variations in nitrite content, high-temperature decomposition of nitrate ions, enrichment of chloride ions, metal corrosion products and impurities, and alkalinity drift, periodic sampling for composition and impurity analysis is necessary to monitor the aging and deterioration of the medium.

[0003] However, the current sampling method has some problems: First, open-top sampling or liquid sampling: Molten salt is scooped out or poured into a container in liquid form. The high-temperature molten salt comes into direct contact with the air. Nitrates easily absorb moisture and carbon dioxide and undergo oxidative decomposition. Nitrite is oxidized. The sample composition is distorted relative to the actual operating state inside the tube, and the analysis results cannot represent the actual medium.

[0004] Second, sample solidification and adhesion to the container or difficulty in cleaning the container: liquid molten salt adheres to the sampling tool and the inner wall of the container, and solidifies into clumps after cooling, which are difficult to remove. The residual salt will also contaminate the next sampling. Third, inconsistent sample standards: The volume, shape and cooling rate of each sample are inconsistent, and the solidification structure and segregation state are different, resulting in a lack of comparability between the analysis results of different times. Fourth, branch blockage: When sampling branches are not arranged properly, molten salt may solidify and cause blockages in the branches, making it difficult to take samples repeatedly. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of sampling distortion, container cleaning difficulties, impact on secondary sampling, inconsistent sample standards, incomparability of samples, and clogging of the sampling system in the prior art, and to provide an online molten salt cooling and solidification sampler and sampling method.

[0006] To achieve the above objectives, the present invention employs the following technical solution: An online molten salt cooling and solidification sampler includes a sampling branch pipe, the upper end of which is connected to the molten salt conveying main pipe, and the lower end outlet is connected to the solidification core mold. A sampling valve is provided at the inlet of the solidification core mold, and a cooling sleeve is fitted on the outside of the solidification core mold. An annular cooling channel is formed between the outer wall of the solidification core mold and the inner wall of the cooling sleeve. The cooling sleeve has a cooling medium inlet and a cooling medium outlet sequentially arranged axially.

[0007] A further improvement of the present invention is that: The sampling valve is located at the lower end of the sampling branch pipe.

[0008] The lower end of the sampling valve is connected to a quick-release clamp, and the lower end of the quick-release clamp is connected to the upper end of the solidified core mold and the cooling sleeve.

[0009] It also includes an exhaust unit, the inlet of which is connected to the inlet end of the solidified core mold.

[0010] The venting unit includes an venting pipe, the inlet of which extends into the inlet end of the solidified core mold, the outlet of which extends to the outside of the solidified core mold, and an venting valve is provided at the outlet end of the venting pipe.

[0011] The sampling branch pipe is located at the lower end of the side wall of the main molten salt transport pipe.

[0012] The solidified core mold is configured as a cylindrical cup body with an open top and a closed bottom wall.

[0013] The cooling medium inlet is located on the side wall near the lower end of the cooling sleeve, and the cooling medium outlet is located on the side wall near the upper end of the cooling sleeve.

[0014] An online molten salt cooling and solidification sampling method based on the sampler described in this invention includes the following steps: With the sampling valve open, the molten salt in the main molten salt delivery pipe enters the solidified core mold through the sampling branch pipe; After the molten salt fills the internal cavity of the solidified core mold, the sampling valve is closed, and the cooling medium is delivered into the annular cooling channel through the cooling medium inlet. The cooling medium flows in the annular channel to cool the molten salt inside the solidified core mold, and finally is discharged through the cooling medium outlet. Once the molten salt inside the solidified core mold has solidified, loosen the quick-release clamps, remove the solidified core mold and cooling sleeve as a whole downwards, and take out the solidified molten salt from inside the solidified core mold to complete the sampling.

[0015] A thermal storage system comprising a high-temperature molten salt circulation pipeline includes an online molten salt cooling and solidification sampler as described in any one of the present invention, wherein the online molten salt cooling and solidification sampler is fixed to the lower end of the side wall of the main molten salt transport pipe via a sampling branch pipe.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses an online molten salt cooling and solidification sampler. The upper end of a sampling branch pipe is connected to the main molten salt delivery pipe, and the lower end is connected to a solidification mandrel. A sampling valve is installed at the inlet of the solidification mandrel, forming a closed sampling passage. This isolates the sampling process from the external atmosphere, preventing the high-temperature molten salt from absorbing moisture, oxidizing, or decomposing due to contact with air during sampling, thus avoiding sample distortion. Furthermore, in this device, the solidification mandrel serves as the receiving and forming container for the molten salt. Each sampling is completed within the inner cavity of the mandrel of the same specification, ensuring that each solidified salt ingot has a consistent composition. The volume and shape of the molten salt are determined, and a cooling medium is introduced through an annular cooling channel to force cooling of the molten salt inside, so that the molten salt solidifies at a similar cooling rate. This ensures that the salt ingots obtained each time have consistent geometric shape and solidification structure, ensuring the comparability of analysis results. In addition, the molten salt solidifies in the solidification mandrel, reducing the probability of it adhering to the inner wall of the sampling branch or valve. Furthermore, the solidification mandrel can be removed after sampling, avoiding the molten salt from remaining and solidifying in the sampling branch and causing blockage. It also facilitates the cleaning and replacement of the solidification mandrel later.

[0017] Furthermore, in this invention, the sampling valve is set at the lower end of the sampling branch pipe, so that the sampling valve is closer to the inlet of the solidified core mold, which shortens the branch length where molten salt may remain after the sampling valve is closed, reduces the amount of molten salt remaining between the sampling valve and the solidified core mold after sampling, and avoids blocking the sampling passage after the residual molten salt in this section cools and solidifies.

[0018] Furthermore, in this invention, the lower end of the sampling valve is connected to a quick-connect clamp, and the lower end of the quick-connect clamp is connected to a solidified core mold, so that the solidified core mold can be quickly and detachably connected to the sampling valve through the quick-connect clamp.

[0019] Furthermore, in this invention, the inlet of the venting unit is connected to the inlet of the solidified core mold, so that when the molten salt flows into the solidified core mold through the sampling branch pipe, the air inside the solidified core mold can be discharged through the venting unit. This avoids the problem of air resistance caused by the inability of gas inside the mold core to be discharged, which would prevent the molten salt from completely filling the inner cavity of the solidified core mold and ensure the consistency of the volume of salt ingots obtained from each sampling.

[0020] Furthermore, in this invention, an exhaust valve is provided at the outlet end of the exhaust pipe. The exhaust valve can be opened during sampling to facilitate the discharge of gas from the cavity, and the exhaust valve can be closed after sampling to seal the solidified core mold, maintain the airtightness of the solidified core mold after sampling, and avoid sample distortion.

[0021] Furthermore, in this invention, the sampling branch pipe is set at the lower end of the side wall of the molten salt conveying main pipe, so that the sampling branch pipe is led vertically downward from the bottom of the main pipe, and the molten salt flows naturally into the sampling branch pipe and the solidified core mold by gravity, which simplifies the sampling operation process.

[0022] Furthermore, in this invention, the solidified core mold is configured as a cylindrical cup with an open top and a closed bottom wall, so that the interior of the solidified core mold forms a cylindrical cavity with a fixed geometric shape, which is convenient for subsequent analysis and processing.

[0023] Furthermore, in this invention, the cooling medium inlet is located on the side wall near the lower end of the cooling sleeve, and the cooling medium outlet is located on the side wall near the upper end of the cooling sleeve. The cooling medium can flow from bottom to top in the annular cooling channel to uniformly cool the outer wall of the solidified core mold.

[0024] This invention discloses an online molten salt cooling and solidification sampling method. The upper end of a sampling branch pipe is connected to the main molten salt delivery pipe, and the lower end is connected to a solidification mandrel. A sampling valve is installed at the inlet of the solidification mandrel, forming a closed sampling passage. This isolates the sampling process from the external atmosphere, preventing the high-temperature molten salt from absorbing moisture, oxidizing, or decomposing due to contact with air during sampling, thus avoiding sample distortion. Furthermore, in this device, the solidification mandrel serves as the receiving and forming container for the molten salt. Each sampling is completed within the inner cavity of the mandrel of the same specification, ensuring that each solidified salt ingot has a consistent composition. The volume and shape of the molten salt are determined, and a cooling medium is introduced through an annular cooling channel to force cooling of the molten salt inside, so that the molten salt solidifies at a similar cooling rate. This ensures that the salt ingots obtained each time have consistent geometric shape and solidification structure, ensuring the comparability of analysis results. In addition, the molten salt solidifies in the solidification mandrel, reducing the probability of it adhering to the inner wall of the sampling branch or valve. Furthermore, the solidification mandrel can be removed after sampling, avoiding the molten salt from remaining and solidifying in the sampling branch and causing blockage. It also facilitates the cleaning and replacement of the solidification mandrel later. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a system structure diagram disclosed in an embodiment of the present invention.

[0027] Wherein: 1-Main molten salt conveying pipe; 2-Sampling branch pipe; 3-Sampling valve; 4-Quick-fit clamp; 5-Solidified core mold; 6-Cooling sleeve; 7-Exhaust valve; 8-Cooling medium inlet; 9-Cooling medium outlet. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present 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, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0034] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1This invention discloses an online molten salt cooling and solidification sampler, specifically a sampling device for online closed sampling and cooling solidification of high-temperature molten salt in operating pipelines. It is applicable to process systems containing high-temperature molten salt circulating pipelines, such as solar thermal power generation, molten salt thermal storage, and molten salt reactors, and aims to solve the following technical problems: First, the entire sampling process should be isolated from air to prevent the sample from absorbing moisture and oxidizing, thus avoiding distortion. Second, after sampling, the sample is rapidly cooled and solidified into standardized salt ingots to ensure that the shape of each sample is consistent and easy to compare. Third, the sampling branch relies on gravity to fill with salt, and the sampling mold core can be extracted and replaced as a whole, avoiding molten salt retention and blockage, and facilitating cleaning and reuse.

[0035] Specifically, it includes the following structure: Example 1 This embodiment discloses an online molten salt cooling and solidification sampler. It should be noted that in this embodiment, the online molten salt cooling and solidification sampler is installed on the main molten salt conveying pipe 1, which conveys high-temperature molten salt. Specifically: Molten salt transport main pipe 1 is the process pipeline in the system that transports molten salt, and the molten salt flows along the pipeline within it.

[0036] Sampling branch pipe 2 extends vertically downward from the bottom of molten salt conveying main pipe 1 and connects to the inner cavity of molten salt conveying main pipe 1, allowing molten salt to flow downward into the sampling branch pipe by its own gravity. The lower end of sampling branch pipe 2 is connected to sampling valve 3, which is used to open and close the sampling passage; the solidified core mold 5 is connected to the lower part of sampling valve 3 via quick-release clamp 4.

[0037] Cooling sleeve 6 is fitted around the outer periphery of solidified core mold 5. The upper ends of cooling sleeve 6 and solidified core mold 5 are connected by a common upper end flange. The upper end flange is suspended by quick-release clamp 4 directly below sampling valve 3. An annular gap is left between the outer wall of solidified core mold 5 and the inner wall of cooling sleeve 6, forming an upper and lower closed annular cooling channel. Cooling sleeve 6 has a cooling medium inlet 8 at the lower part and a cooling medium outlet 9 at the upper part. Cooling medium enters from the lower cooling medium inlet 8, sweeps over the outer wall and bottom of solidified core mold 5 from bottom to top in the closed annular cooling channel, and is discharged from the cooling medium outlet 9, forming a forced convection heat transfer from bottom to top.

[0038] The exhaust valve 7 is installed at the outlet of the exhaust pipe. The top of the cavity of the solidified core mold 5 is connected to the exhaust valve 7 through the exhaust pipe. When molten salt is filled, the gas in the cavity is discharged through the exhaust pipe and the exhaust valve 7, so that the molten salt fills the cavity and is sealed after sampling.

[0039] Furthermore, in this embodiment, the sampling valve 3 can be a ball valve or a shut-off valve, used to open during sampling and close after sampling to isolate the main pipe. The quick-connect clamp 4 adopts a clamp-type quick-connect connector, which facilitates the quick assembly and disassembly of the solidified core mold 5.

[0040] Furthermore, in this embodiment, the solidified core mold 5 is a hollow, thick-walled cup with an open top and a closed bottom. The upper opening of its cup cavity faces the sampling branch, and molten salt falls freely into the cavity from the cup opening and accumulates and fills from the bottom upwards.

[0041] Furthermore, in this embodiment, the solidified core mold 5 is a metal cup body, which can be made of stainless steel or nickel-based alloy, with a large wall thickness to provide sufficient heat capacity and ensure the demolding strength of the salt ingot.

[0042] Furthermore, in this embodiment, the cooling medium can be compressed air, water, or other heat-conducting media. The cooling medium enters through the cooling medium inlet 8, sweeps over the outer wall of the solidified core mold 5 from bottom to top in the annular cooling channel, and is discharged from the cooling medium outlet 9, forming a forced convection heat transfer from bottom to top.

[0043] Example 2 This embodiment also discloses an online molten salt cooling and solidification sampling method, including the following steps: Open the exhaust valve 7 and sampling valve 3. The molten salt in the main pipe 1 falls by gravity through the sampling branch pipe 2, falls into the open cup cavity of the solidified core mold 5 and accumulates from the bottom to the top. The gas in the cavity is discharged through the exhaust pipe and exhaust valve 7. After the molten salt fills the cup cavity, the sampling valve 3 is closed to isolate the sampler from the main pipe, and the exhaust valve 7 is closed to seal the cup cavity. Then, cooling medium is introduced into the cooling medium inlet 8, and the solidified core mold 5 is forcibly cooled through the annular cooling channel, so that the molten salt in the cavity quickly solidifies into a salt ingot.

[0044] After solidification is complete, stop cooling, loosen the quick-release clamp 4, and pull the jacket assembly consisting of the solidified core mold 5 and the cooling sleeve 6, along with the salt ingot, downwards to eject the standard salt ingot. After cleaning, reassemble and proceed with the next sampling.

[0045] By replacing the jacket mold core components of different specifications, standard salt ingots of different volumes can be obtained; the flow rate and temperature of the cooling medium can be adjusted according to the type of molten salt and the required solidification rate.

[0046] Example 3 This embodiment also discloses a thermal storage system including a high-temperature molten salt circulation pipeline, including the online molten salt cooling and solidification sampler disclosed in Embodiment 1. The online molten salt cooling and solidification sampler is fixed to the lower end of the side wall of the molten salt conveying main pipe 1 through the sampling branch pipe 2.

[0047] This embodiment has the following effects: First, the entire process is enclosed and air-isolated: sampling, salt filling and solidification are all completed in a closed cavity to avoid molten salt absorbing moisture, oxidation and decomposition, and to ensure that the sample composition truly reflects the medium running inside the tube.

[0048] Second, rapid solidification and standardized salt ingots: the annular cooling channel with forced convection cooling from bottom to top allows the salt sample to solidify rapidly; each time it is formed in the same specification mold core, the salt ingot volume and shape are consistent, and samples from different times can be directly compared, improving the comparability and repeatability of the analysis.

[0049] Third, gravity-fed salt filling and reliable structure: The sampling branch pipe is led vertically downward from the bottom of the main pipe and fills with salt by gravity, without the need for additional power or siphon. The structure is simple and the salt filling is sufficient.

[0050] Fourth, quick installation and easy to reuse: The jacket mold core assembly is hoisted by quick-installation clamps and can be pulled out as a whole for ingot removal and cleaning, allowing for rapid replacement and avoiding residual salt contamination and branch blockage.

[0051] Fifth, online operation: sampling can be performed while the system is running without stopping the machine or draining the pipeline.

[0052] Sixth, the structure of the jacket seal is more reliable: the cooling sleeve and the solidified core mold 5 are sealed at both ends to form a sealed jacket. The cooling medium only enters and exits through the cooling medium inlet 8 and the cooling medium outlet 9. The cooling circuit is self-sealed and does not leak.

[0053] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An online molten salt cooling and solidification sampler, characterized in that, Includes a sampling branch pipe (2), the upper end of which is connected to the molten salt conveying main pipe (1), and the lower end outlet is connected to the solidification core mold (5). A sampling valve (3) is provided at the inlet of the solidification core mold (5). A cooling sleeve (6) is sleeved on the outside of the solidification core mold (5). An annular cooling channel is formed between the outer wall of the solidification core mold (5) and the inner wall of the cooling sleeve (6). The cooling sleeve (6) has a cooling medium inlet (8) and a cooling medium outlet (9) sequentially opened in the axial direction.

2. The online molten salt cooling and solidification sampler according to claim 1, characterized in that, The sampling valve (3) is located at the lower end of the sampling branch pipe (2).

3. The online molten salt cooling and solidification sampler according to claim 2, characterized in that, The sampling valve (3) is connected to a quick-release clamp (4) at its lower end, and the quick-release clamp (4) is connected to the upper end of the solidified core mold (5) and the cooling sleeve (6) at its lower end.

4. The online molten salt cooling and solidification sampler according to claim 1, characterized in that, It also includes an exhaust unit, the inlet of which is connected to the inlet end of the solidified core mold (5).

5. The online molten salt cooling and solidification sampler according to claim 4, characterized in that, The exhaust unit includes an exhaust pipe, the inlet of which extends into the inlet end of the solidified core mold (5), the outlet of which extends to the outside of the solidified core mold (5), and an exhaust valve (7) is provided at the outlet end of the exhaust pipe.

6. The online molten salt cooling and solidification sampler according to claim 1, characterized in that, The sampling branch pipe (2) is located at the lower end of the side wall of the molten salt conveying main pipe (1).

7. The online molten salt cooling and solidification sampler according to claim 1, characterized in that, The solidified core mold (5) is configured as a cylindrical cup with an open top and a closed bottom wall.

8. The online molten salt cooling and solidification sampler according to claim 1, characterized in that, The cooling medium inlet (8) is located on the side wall of the cooling sleeve (6) near the lower end, and the cooling medium outlet (9) is located on the side wall of the cooling sleeve (6) near the upper end.

9. A method for online molten salt cooling and solidification sampling based on the sampler described in claim 1, characterized in that, Includes the following steps: Open the sampling valve (3), and the molten salt in the molten salt conveying main pipe (1) enters the solidified core mold (5) through the sampling branch pipe (2); After the molten salt fills the internal cavity of the solidified core mold (5), the sampling valve (3) is closed, and the cooling medium is delivered into the annular cooling channel through the cooling medium inlet (8). The cooling medium flows in the annular channel to cool the molten salt inside the solidified core mold (5), and finally is discharged through the cooling medium outlet (9). After the molten salt inside the solidified core mold (5) has solidified, remove the solidified core mold (5) and cooling sleeve (6), and take out the solidified molten salt from inside the solidified core mold (5) to complete the sampling.

10. A thermal storage system comprising a high-temperature molten salt circulation pipeline, characterized in that, The online molten salt cooling and solidification sampler according to any one of claims 1-8 is fixed to the lower end of the side wall of the molten salt conveying main pipe (1) via a sampling branch pipe (2).

Images