Piston type alkali metal heat pipe quantitative filling device and working method

Abstract

The application discloses a piston type alkali metal heat pipe quantitative filling device and a working method thereof. The device comprises a storage tank, a purification tank, a piston type quantitative barrel, a heat pipe shell and a vacuum valve. The storage tank is used for storing and heating and melting alkali metal. The purification tank removes impurities in liquid alkali metal. The heat pipe shell is used for storing high-purity liquid alkali metal. The vacuum valve is used for controlling the circulation of liquid alkali metal. The application further discloses a working method of the quantitative filling device, which can ensure the quantitative and clean filling of the alkali metal heat pipe during the working medium filling process, and improves the heat transfer performance and service life of the heat pipe.

Description

Technical Field

[0001] This invention relates to the field of phase change heat exchange equipment technology, specifically to a piston-type alkali metal heat pipe quantitative filling device and its working method. Background Technology

[0002] High-temperature heat pipes are heat transfer elements that use alkali metals as the working medium. Due to the very high latent heat of vaporization of alkali metals, a small amount of medium can carry a large amount of heat in high-temperature environments. High-temperature heat pipes possess advantages such as high thermal conductivity, excellent isothermal properties, simple structure, and low cost. They also exhibit strong environmental adaptability, are easy to install and maintain, and can avoid single-point failures, thus improving inherent safety. However, the current processing and manufacturing of alkali metal heat pipes still suffers from problems such as non-standardization and poor cleanliness, making it impossible to guarantee the purity of the alkali metal. This may also introduce impurities and non-condensable gases, reducing the amount of working fluid and posing certain safety hazards.

[0003] Several patents exist regarding the filling of working fluids in high-temperature heat pipes. For example, Chinese patent 202210550310.5 proposes a quantitative filling device and method for high-temperature sodium heat pipes. Its main feature is the use of a known-volume tank of a specific volume for quantitative filling of liquid sodium. Different known-volume tanks are used depending on the volume of liquid sodium to be filled into the heat pipe shell, achieving quantitative filling. A vacuum pump and vacuum gauge are used in the pipeline to evacuate the heat pipe shell, facilitating the pressure difference to draw liquid sodium into the shell. However, on the one hand, the filling circuit designed in this patent is only suitable for high-temperature sodium heat pipes with small filling volumes. For different types of liquid alkali metals, due to their varying densities, using a known-volume tank requires preparation, processing, and tank replacement, resulting in high processing costs and compromised sealing when frequent replacements are needed. On the other hand, using a known-volume tank requires a vacuum system in the circuit, making the circuit more lengthy and difficult to seal. Furthermore, there is a possibility that liquid metal may be drawn into the vacuum circuit, affecting filling accuracy.

[0004] For example, Chinese Patent 202110972295.9 proposes a high-temperature heat pipe quantitative filling device and method. Its key feature is the use of a communicating vessel formed by a calibration tube and a level gauge for liquid level calibration. The liquid working fluid flows simultaneously into both the calibration tube and the level gauge, and the volume of the working fluid in the calibration tube is read from the level gauge. This invention can fill different volumes and types of alkali metals, and the circuit is simple and its sealing is guaranteed. However, because the level gauge and calibration tube in this invention need to ensure accuracy, their diameters and volumes are relatively small. When using vacuum pressure difference to quantitatively fill the working fluid, the flow rate of the liquid working fluid is relatively high. Furthermore, as the level gauge is an electronic device, its response time is time-consuming, making it impossible to guarantee that the liquid level in the calibration tube reaches the required filling accuracy. Summary of the Invention

[0005] To ensure the standardization of high-temperature sodium heat pipe manufacturing, this invention designs a piston-type alkali metal heat pipe quantitative filling device and its working method. The principle is ingenious, and it can ensure the standardization of the filling medium during the manufacturing of high-temperature sodium heat pipes. This can guarantee the quantitative and cleanliness of the alkali metal heat pipe during the filling process, and ensure the heat transfer performance and service life of the high-temperature alkali metal heat pipe.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A piston-type alkali metal heat pipe quantitative filling device includes a storage tank 1, a purification tank 2, a piston-type quantitative container 3, a heat pipe shell 4, a storage tank lower isolation valve 5, a quantitative container isolation valve 6, and a heat pipe shell isolation valve 7. The outlet of the storage tank 1 is connected to the upper part of the purification tank 2 via a pipeline. The storage tank lower isolation valve 5 is installed in the middle of the pipeline to control the quality of the liquid alkali metal in the purification tank 2. The lower part of the purification tank 2 is connected to a bend, which is connected to the piston-type quantitative container 3 via the quantitative container isolation valve 6. The quantitative container isolation valve 6 is used to ensure the quality of the clean liquid alkali metal in the quantitative container. The lower part of the piston-type quantitative container 3 is connected to the heat pipe shell isolation valve 7, and is connected to the heat pipe shell 4 via a pipeline. The heat pipe shell isolation valve 7 is used to ensure the filling quality. Heating wires 8 and thermocouples are arranged on the outside of the storage tank 1, purification tank 2, piston-type quantitative container 3, and pipeline to ensure the melting of alkali metal and temperature monitoring. A connecting pipe 11 is provided at the upper part of the storage tank 1, which is connected to the upper part of the piston-type quantitative container 3.

[0008] The piston-type metering container 3 uses a piston structure to perform metering of liquid alkali metal. The piston-type metering container 3 is equipped with a piston 10 and a piston push rod 9 connected to each other. External force is used to press the liquid alkali metal into the heat pipe shell 4 using the piston 10. The piston push rod 9 is designed with a scale, and a marking line is arranged at the inlet of the piston push rod 9. The volume of liquid alkali metal is calculated by the downward pressing distance of the piston push rod 9, so as to realize the metering of alkali metal.

[0009] The piston-type metering container 3 employs a metal hard seal, rubber seal, or PTFE seal for the sealing of the piston 10 and piston push rod 9 to ensure the sealing and compatibility of the liquid alkali metal. The internal vacuum leakage rate of the piston-type metering container 3 is not less than 10%. -9 Pa·m3 / s.

[0010] The storage tank 1, purification tank 2, piston-type metering tank 3, and pipelines are made of 316 stainless steel to ensure compatibility during the alkali metal melting and flow process.

[0011] The storage tank bottom isolation valve 5, metering tank isolation valve 6, and heat pipe shell isolation valve 7 are high-temperature vacuum valves, and the sealing methods of the high-temperature vacuum valves are metal hard seals, rubber seals, or PTFE seals.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] The filling device used in this invention features high vacuum and good sealing, ensuring the cleanliness of the alkali metal. This device utilizes the fluidity of liquid alkali metal and relies on gravity for purification, offering good applicability and guaranteeing the purity of the liquid metal. A piston-type metering tank is used to quantify the alkali metal based on pressure, resulting in high metering accuracy and fast response, suitable for various filling needs. The piston-type metering tank ensures that the alkali metal can be quantitatively dispensed in liquid form and filled into the heat pipe, allowing the heat pipe to be properly wetted after filling. The design directly removes air from the heat pipe shell, preventing the alkali metal from being oxidized.

[0014] This invention proposes a piston-type quantitative filling device for high-temperature alkali metal heat pipes, which can ensure quantitative and clean filling of alkali metal heat pipes during the working fluid filling process, thereby improving the heat transfer performance and service life of the heat pipes. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the piston-type alkali metal heat pipe quantitative filling device of the present invention. Detailed Implementation

[0016] To better illustrate the present invention, it will now be further described in conjunction with examples and accompanying drawings:

[0017] like Figure 1 As shown, this invention discloses a piston-type alkali metal heat pipe quantitative filling device, comprising a storage tank 1, a purification tank 2, a piston-type quantitative container 3, a heat pipe shell 4, a storage tank lower isolation valve 5, a quantitative container isolation valve 6, and a heat pipe shell isolation valve 7. The outlet of the storage tank 1 is connected to the upper part of the purification tank 2 via a pipe. The storage tank lower isolation valve 5 is installed in the middle of the pipe to control the quality of the liquid alkali metal in the purification tank 2. A bend is connected to the lower part of the purification tank 2, which is connected to the piston-type quantitative container 3 via the quantitative container isolation valve 6. The quantitative container isolation valve 6 ensures the quality of the clean liquid alkali metal in the quantitative container. The lower part of the piston-type quantitative container 3 is connected to the heat pipe shell isolation valve 7, which is connected to the heat pipe shell 4 via a pipe. The heat pipe shell isolation valve 7 ensures the filling quality. Heating wires 8 and thermocouples are arranged on the outside of the storage tank 1, purification tank 2, and piston-type quantitative container 3, as well as the pipes, to ensure the melting of the alkali metal and temperature monitoring. A connecting pipe 11 is provided at the upper part of the storage tank 1, connecting to the upper part of the piston-type quantitative container 3.

[0018] In a preferred embodiment of the present invention, the piston-type metering container 3 uses a piston structure to perform the metering action of liquid alkali metal. External force is used to press the liquid alkali metal into the heat pipe shell 4 using the piston 10. The piston push rod 9 is designed with a scale, and a marking line is arranged at the inlet of the piston push rod 9. The volume of liquid alkali metal is calculated by the downward pressing distance of the piston push rod 9, thereby realizing the metering of alkali metal.

[0019] In a preferred embodiment of the present invention, the piston 10 and piston push rod 9 of the piston-type metering tank 3 are sealed using a metal hard seal, rubber seal, or PTFE seal to ensure the sealing performance and compatibility of the liquid alkali metal. The vacuum leakage rate inside the piston-type metering tank 3 is not less than 10%. -9 Pa·m3 / s.

[0020] In a preferred embodiment of the present invention, the storage tank 1, purification tank 2, piston-type metering tank 3, and pipeline are made of 316 stainless steel to ensure compatibility during the melting and flow of alkali metals.

[0021] In a preferred embodiment of the present invention, the storage tank bottom isolation valve 5, the metering tank isolation valve 6, and the heat pipe shell isolation valve 7 are high-temperature vacuum valves, and the high-temperature vacuum valves adopt metal hard seals.

[0022] The working principle of this invention is as follows: The piston 10 inside the piston-type metering tank 3 is pushed to the bottom. The upper part of the storage tank 1 is opened, solid alkali metal is placed inside, all valves are opened, and rare gas is introduced for protection. Then, all valves are closed, and the heating wire 8 is powered to heat the storage tank 1 at a temperature 20°C above the melting point of the alkali metal to ensure complete melting. After the alkali metal is completely melted, the lower isolation valve 5 of the storage tank is opened, and the liquid alkali metal flows into the purification tank 2 to remove impurities and is stored in the purification tank 2. Then, the storage tank is closed. Lower the isolation valve 5, open the metering tank isolation valve 6, and pull the piston push rod 9 upward. Due to the pressure conservation environment provided by the connecting pipe 11, the liquid alkali metal will be drawn into the piston-type metering tank 3. After the liquid alkali metal is full, close the metering tank isolation valve 6, open the heat pipe shell isolation valve 7, record the initial scale of the piston push rod 9, calculate the scale corresponding to the metered alkali metal volume, slowly press the piston push rod 9, observe that the scale on the piston push rod 9 reaches the specified scale, and then close the heat pipe shell isolation valve 7 to complete the metered filling of alkali metal in the heat pipe.

Claims

1. A piston-type alkali metal heat pipe quantitative filling device, characterized in that: The system includes a storage tank (1), a purification tank (2), a piston-type metering container (3), a heat pipe shell (4), a storage tank lower isolation valve (5), a metering container isolation valve (6), and a heat pipe shell isolation valve (7). The outlet of the storage tank (1) is connected to the upper part of the purification tank (2) via a pipeline. A storage tank lower isolation valve (5) is installed in the middle of the pipeline to control the mass of liquid alkali metal in the purification tank (2). The lower part of the purification tank (2) is connected to a bend pipe, which is connected to the piston-type metering container (3) via the metering container isolation valve (6). Used to ensure the quality of clean liquid alkali metal in the metering tank; the lower part of the piston metering tank (3) is connected to a heat pipe shell isolation valve (7), and is connected to the heat pipe shell (4) through a pipe. The heat pipe shell isolation valve (7) is used to ensure the filling quality; heating wires (8) and thermocouples are arranged on the outside of the storage tank (1), purification tank (2), piston metering tank (3) and pipes to ensure the melting of alkali metal and temperature monitoring; a connecting pipe (11) is left at the top of the storage tank (1), which is connected to the top of the piston metering tank (3); The piston-type metering container (3) uses a piston structure to perform the metering action of liquid alkali metal. The piston-type metering container (3) is equipped with a piston (10) and a piston push rod (9) connected to each other. The external force is used to press the liquid alkali metal into the heat pipe shell (4) by the piston (10). The piston push rod (9) is designed with a scale and a marking line is arranged at the inlet of the piston push rod (9). The volume of liquid alkali metal is calculated by the downward pressing distance of the piston push rod (9), so as to realize the metering of alkali metal. The working method of the piston-type alkali metal heat pipe quantitative filling device is as follows: The piston (10) inside the piston-type quantitative tank (3) is pushed to the bottom. The upper part of the storage tank (1) is opened, solid alkali metal is placed in, all valves are opened, and rare gas is introduced for protection. Then, all valves are closed, and the heating wire (8) is powered to heat the storage tank (1). The heating temperature is higher than the melting point of the alkali metal to ensure complete melting of the alkali metal. After the alkali metal is completely melted, the lower isolation valve (5) of the storage tank is opened, and the liquid alkali metal flows into the purification tank (2) to remove impurities and is stored in the purification tank (2). Then, the valve is closed. Open the isolation valve (5) at the bottom of the storage tank, open the isolation valve (6) of the metering tank, and pull the piston push rod (9) upward. Due to the pressure conservation environment provided by the connecting pipe (11), the liquid alkali metal will be sucked into the piston metering tank (3). After the liquid alkali metal is full, close the isolation valve (6) of the metering tank, open the isolation valve (7) of the heat pipe shell, record the initial scale of the piston push rod (9), calculate the scale corresponding to the metered alkali metal volume, slowly press the piston push rod (9), observe that the scale on the piston push rod (9) reaches the specified scale, close the isolation valve (7) of the heat pipe shell, and complete the metered filling of alkali metal in the heat pipe.

2. The piston-type alkali metal heat pipe quantitative filling device according to claim 1, characterized in that: The piston (10) and piston push rod (9) of the piston-type metering container (3) are sealed by metal hard seal, rubber seal or PTFE seal to ensure the sealing performance and compatibility of liquid alkali metal. The vacuum leakage rate inside the piston-type metering container (3) is not less than 10%. -9 Pa·m 3 / s.

3. The piston-type alkali metal heat pipe quantitative filling device according to claim 1, characterized in that: The storage tank (1), purification tank (2), piston-type metering tank (3) and pipeline are made of 316 stainless steel to ensure compatibility during the melting and flow of alkali metals.

4. The piston-type alkali metal heat pipe quantitative filling device according to claim 1, characterized in that: The storage tank bottom isolation valve (5), metering tank isolation valve (6), and heat pipe shell isolation valve (7) use high-temperature vacuum valves. The sealing method of the high-temperature vacuum valve is metal hard seal, rubber seal or PTFE seal.

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