Molten salt stop valve

Abstract

The utility model relates to a fused salt stop valve, which belongs to the field of fused salt and is important equipment for controlling connection and disconnection of a fused salt medium pipeline and ensuring normal operation of a unit. In the production and machining process of the valve, the machining forming difficulty of the internal structure of the valve body and the surfacing welding difficulty of a sealing surface are relatively large, so that the manufacturing difficulty needs to be properly reduced while the sealing performance and other performance are ensured, and meanwhile, due to the fact that the difference between the viscosity of a fused salt medium and the viscosity of a steam-water medium is large, the energy loss in the medium flowing process is large. In order to solve the problem, according to the scheme, the valve body is divided into the upper valve body and the lower valve body which are fixedly connected through a flange, and the surfacing machining difficulty of the interior of the valve body and the sealing face is effectively reduced; the head of the valve element rod is machined into a spherical surface, medium flow resistance is reduced, and energy loss is reduced; in order to ensure that the reverse sealing performance of the valve is good, a plane is machined on the neck portion of the valve element rod, the valve element rod and the valve cover can form a conical sealing face and a plane sealing face when the valve is opened, the reverse sealing performance is good, and packing is protected from being affected by molten salt media to the maximum extent.

Description

Technical Field

[0001] The utility model relates to a molten salt stop valve, belonging to the field of molten salt. Background Art

[0002] The globe valve is installed on the molten salt pipeline of a thermal power unit as an opening and closing device. It is an important device to ensure the normal operation of the unit. The valve stem is driven by an electric device or manual mechanism to make linear motion to achieve the flow or blockage of the medium.

[0003] As the temperature and pressure of the media in the molten salt valve field become higher and higher, the internal dimensional accuracy of the valve body becomes higher and higher, and the processing difficulty also increases accordingly. At the same time, various parameters such as the viscosity of the molten salt medium are also quite different from those of the steam-water medium, and the requirements for sealing performance are also getting higher and higher. Summary of the Invention

[0004] In order to solve the defects of the above-mentioned technology, the utility model provides a split stop valve which reduces the processing difficulty to the greatest extent and reduces the flow resistance during the flow of the medium.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: the valve body is divided into two parts, the two parts are connected by flanges, the upper part of the upper valve body is connected to the valve cover by bolts, and the upper and lower parts of the valve body are respectively connected to the valve inlet and outlet pipes through flange structures. The split structure greatly reduces the difficulty of forming the interior of the valve body and processing the sealing surface. The valve disc and the valve stem are processed into one piece to form a valve core rod. At the same time, the head of the valve core rod is processed into a spherical shape, and an annular groove is processed to reduce the flow resistance. A plane is processed on the neck of the valve core rod to form a two-layer inverted sealing structure of a conical surface and a flat surface with the valve cover, which has a better inverted sealing effect than the traditional conical inverted seal; the valve cover inverted sealing part is welded with a sealing pair with a hardness of HRC35-40; the upper valve body is welded with a sealing surface with a conical angle of 74.5°~75°.

[0006] It comprises a lower valve body (1), an upper valve body (2), a valve core rod (3), a valve cover (4), a packing assembly (5), a packing gland (6), a packing pressure plate (7), a pointer (8), a bracket (9), an electric assembly (10), etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a schematic diagram of the structure of a split molten salt stop valve with upper and lower valve bodies.

[0008] Figure 2 This is a schematic diagram of the valve stem head structure

[0009] In the figure, 1. Lower valve body, 2. Upper valve body, 3. Valve core stem, 4. Valve cover, 5. Packing assembly, 6. Packing gland, 7. Packing pressure plate, 8. Pointer, 9. Bracket, 10. Electrical assembly. DETAILED DESCRIPTION

[0010] The molten salt stop valve comprises an upper valve body and a lower valve body, which are connected by a flange and equipped with a spiral wound gasket to ensure sealing. The valve body is machined in two separate parts, effectively reducing the difficulty of machining the valve body interior and sealing surface. By adjusting the valve body structure, the difficulty of machining and sealing surface cladding is reduced, making the processing more convenient. During the machining of the valve body cavity and cladding of the sealing surface, tools or other tools can enter the cavity from the upper part of the upper valve body or the side of the flange, which is less difficult to process than the traditional molten salt stop valve body. The traditional valve disc and valve stem are machined into a single unit to form the valve core stem. The valve core stem head structure is adjusted to ensure good valve sealing performance while reducing medium flow resistance.

[0011] exist Figure 2 In the embodiment shown, the valve core rod head is processed into a spherical shape. When the medium flows through the valve core rod head, the spherical structure can effectively reduce the energy loss of the medium and reduce the flow resistance. At the same time, during the opening and closing process, the sealing surface will not be damaged due to the expansion and contraction of the outer diameter, thereby ensuring good sealing.

[0012] exist Figure 2 In the illustrated embodiment, when the valve stem is fully opened, it forms a tapered upper seal with the valve cover, effectively sealing the valve. This prevents high-temperature media from entering the packing chamber through the gap between the valve cover and the stem, potentially damaging the packing and affecting the valve's performance. Simultaneously, the flat surface of the stem neck and the bottom surface of the valve cover form a secondary flat seal, further enhancing the sealing effect, protecting the packing, and extending its service life.

[0013] The upper valve body is welded with a sealing pair to reduce damage to the sealing surface and extend the service life of the valve. The sealing pair cone angle is 74.5°~75°, which can make up for the sealing surface gap caused by manufacturing and installation errors. When the sealing surface is tilted, the sealing surface can contact more evenly, the friction will be greatly reduced, and the service life of the valve will be extended.

[0014] During the use of the valve, due to high temperature and high pressure corrosion factors, the sealing surface is prone to wear and corrosion when the valve is frequently operated, resulting in a decrease in sealing performance. A sealing pair is butt-welded at the contact sealing part between the valve cover and the valve core rod to enhance the sealing of the valve, prevent leakage, and increase the service life of the valve. The sealing surface surfacing hardness HRC = 35~40 forms a hardness difference with the valve core rod. The existence of the hardness difference can make the sealing surface form a better deformation fit when under pressure, thereby enhancing the tightness and durability of the seal.

[0015] exist Figure 2In the embodiment shown, the head of the valve core rod is processed into an "I" shape, and a guide ring surface is formed in the middle to reduce the erosion of the medium on the valve stem; at the same time, the contact area between the valve core rod and the upper valve body is reduced, the friction is reduced, and the force of the valve core rod lifting and lowering is reduced, thereby extending the service life of the valve and reducing the cost of the valve.

Claims

1. A molten salt stop valve, characterized by: The utility model comprises a lower valve body (1), an upper valve body (2), a valve core rod (3), a valve cover (4), a packing assembly (5), a packing pressure cover (6), a packing pressure plate (7), a pointer (8), a bracket (9), and an electric device (10). The lower valve body (1) and the upper valve body (2) are fixedly connected by a flange, the valve core rod (3) is located inside the upper valve body, the valve cover and the upper valve body are connected by bolts, the packing assembly is located inside the valve cover (4), the electric device (10) is connected to the valve cover (4) through the bracket (9), the pointer (8) is fixed on the valve core rod (3), and the lower valve body (1) and the upper valve body (2) are connected to the pipeline through a flange structure.

2. A molten salt stop valve according to claim 1, characterized in that: The head of the valve core rod (3) is spherical.

3. The molten salt stop valve according to claim 1, characterized in that: When the valve core rod (3) rises to the highest point, the valve core rod and the valve cover form a conical surface seal, and the plane of the neck of the valve core rod (3) and the bottom surface of the valve cover can form a second layer of plane seal.

4. The molten salt stop valve according to claim 1, characterized in that: A conical sealing pair is built-up welded on the upper valve body (2), and the angle of the conical surface is 74.5° to 75°.

5. The molten salt stop valve according to claim 1, characterized in that: A sealing pair is built-up welded on the contact portion between the valve cover (4) and the valve stem, and the build-up weld hardness HRC=35-40.

6. The molten salt stop valve according to claim 1, characterized in that: The valve core rod (3) and the upper valve body (2) are machined with an annular guide groove.

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