CN201306465Y - Up-loading ball valve of handling system for high temperature gas cooled reactor fuel at first nuclear level. - Google Patents

Abstract

The utility model provides a ball valve for a fuel loading and unloading system of a nuclear first-stage top-mounted high-temperature gas-cooled reactor, which solves the technical problems existing in conventional fixed ball valves. The utility model adopts a top-mounted structure, and the valve is composed of core components such as an electric drive device, a valve stem, and a ball; the valve stem adopts a "multi-layer shaft seal"structure; the opening and closing of the ball adopts a double positioning structure; the valve seat is designed as a sleeve type , the adjusting pad adjacent to the valve seat can be rotated to the vacancy where its protruding part is embedded in the shoulder of the valve seat, and the ball can be taken out from the valve body when the valve seat retreats away from the ball; Consists of a plurality of cylindrical helical compression springs placed in a spring retaining ring that presses against the seat shoulder. The utility model is convenient for online disassembly, maintenance and replacement of vulnerable parts, and can replace and repair all internal parts of the valve; it ensures that the external leakage rate is ≤1×10 ^-6 Pa·m ³ /s under the condition of helium, and the internal Leakage rate≤1× ^10-3 Pa·m ³ /s.

Description

Ball valve for fuel loading and unloading system of nuclear first-level top-mounted high-temperature gas-cooled reactor

technical field

The utility model relates to a ball valve, in particular to a ball valve for a fuel loading and unloading system of a nuclear first-stage top-mounted high-temperature gas-cooled reactor.

Background technique

Conventional trunnion ball valves are usually: composed of a left valve body, an upper valve cover, a rotating valve stem, a right valve body, a ball and a lower valve cover. The upper bonnet is connected with the left valve body through bonnet bolts; the left valve body and the right valve body are connected with valve body bolts and nuts. The rotating stem drives the ball to rotate, controlling the opening and closing of the ball valve.

The valve cannot be repaired and replaced on-line; the inner and outer tightness and the positioning accuracy of the valve opening and closing cannot meet the requirements of the ball valve for the nuclear first-level high-temperature gas-cooled reactor fuel handling system;

Contents of the invention

The utility model provides a ball valve for a fuel loading and unloading system of a nuclear first-level top-mounted high-temperature gas-cooled reactor, which adopts a top-mounted structure, a multi-layer shaft seal and a fixed ball structure, and solves the technical problems existing in conventional fixed ball valves.

The technical scheme adopted by the utility model is: the upper half of the ball valve is installed on the lower half of the ball valve from top to bottom; the top of the upper half of the ball valve is a valve cover, and the bottom of the valve cover is an electric drive device; Cartridge seat, the ball is embedded in the center of the sleeve seat, and the inlet sealing structure is installed between the ball and the sleeve seat; the valve stem sealing structure is installed on the upper part of the sleeve seat.

The sealing structure of the valve stem forms a sealing mechanism through a gasket, an O-ring, an upper packing, and a lower packing; The medium (helium) is released to a safe area through the leakage device; the upper packing is pressed against the packing gland, and the packing gland is pressed by the disc spring group.

The opening and closing of the sphere adopts a double positioning structure. In addition to setting the limit part in the electric drive device, a mechanical limit device-limit plate is specially set at the bracket.

The valve seat is designed as a sleeve. The adjusting pad adjacent to the valve seat can be rotated to the vacancy where its protruding part is embedded in the shoulder of the valve seat, the valve seat can withdraw from the ball, and the ball can be taken out from the valve body.

The sealing pretightening specific pressure loading of the inlet sealing structure is composed of a plurality of cylindrical helical compression springs placed in the spring retaining ring and exerting pressure on the shoulder of the valve seat.

Because the utility model adopts the top-mounted structure, the valve seat is designed as a sleeve type, which is convenient for online disassembly, maintenance and replacement of vulnerable parts, and can perform replacement and maintenance of all internal parts of the valve; The structure ensures that the external leakage rate is ≤1×10 ^-6 Pa·m ³ /s and the internal leakage rate is ≤1×10 ^-3 Pa·m ³ /s under the condition of helium.

Description of drawings

The utility model is described in further detail below in conjunction with accompanying drawing and specific embodiment.

Fig. 1 Schematic diagram of the ball valve structure of the fuel loading and unloading system of the first-level nuclear top-loading high-temperature gas-cooled reactor;

Figure 2 Schematic diagram of valve stem sealing structure;

Fig. 3 Schematic diagram of the structure of the middle leakage device;

Figure 4 Schematic diagram of sleeve valve seat structure;

Figure 5 Schematic diagram of the inlet seal structure.

Explanation of the icons in the figure: electric drive device 1, valve stem 2, ball 3, disc spring group 4, packing gland 5, upper packing 6, packing spacer 7, lower packing 8, intermediate leakage device 9, O-ring 10. Gasket 11, bracket 12, mechanical limit device-limit plate 13, adjustment pad 14, valve seat 15, cylindrical helical compression spring 16, spring retaining ring 17.

Detailed ways

The utility model is used in the fuel loading and unloading system of the "pebble bed modular high temperature gas-cooled reactor nuclear power plant" to ensure the integrity of the pressure boundary, the isolation of pipelines during atmosphere switching and equipment maintenance.

As shown in Figure 1, the upper half of the ball valve is installed on the lower half of the ball valve from top to bottom; the core components are the electric drive device 1, the valve stem 2, and the ball 3, and the working method is: the valve stem 2 is driven by the electric drive device 1 The ball 3 rotates, thereby realizing the opening and closing of the valve.

As shown in Figure 2, the sealing structure of the valve stem ensures that its external leakage rate is ≤1×10 ^-6 Pa·m ³ /s under the condition of helium. The valve stem 2 is composed of a sealing gasket 11, an O-ring 10, an upper packing 6 and a lower packing 8 to form a sealing mechanism to prevent leakage during the working rotation; Spacer ring 7. The packing gland 5 is compressed by the disc spring group 4 to ensure the sealing specific pressure required for compressing the packing, so that the packing pressing force remains basically constant.

The sphere adopts a double positioning structure. In addition to setting the limiting parts in the electric drive device 1 (see FIG. 1 ), the bracket 12 is specially provided with a mechanical limiting device - a limiting plate 13 . The double positioning structure can ensure the precise control of the opening and closing position of the valve, and the valve channel is smooth and unobstructed.

As shown in Figure 3, an intermediate leakage device 9 is provided on the packing spacer ring 7, and the medium leaked into the stuffing box is discharged to a safe area through the leakage device 9.

As shown in Figure 4, the valve seat 15 is designed as a sleeve type. During maintenance, the adjustment pad 14 adjacent to the valve seat 15 is rotated to the vacancy where its protruding part is embedded in the shoulder of the valve seat 15, and the valve seat 15 can be retracted. From the sphere 3, after the sphere 3 is taken out, the replacement and maintenance of all internal parts of the valve can be carried out.

As shown in Figure 5, the seal pretightening specific pressure loading of the inlet seal structure is composed of a plurality of cylindrical helical compression springs 16 placed in the spring retaining ring 17 and exerting pressure on the shoulder of the valve seat 15, and the spring force is evenly applied to the seal. On the vice, ensure the pre-tightening sealing specific pressure required by the sealing surface of the valve.

The ball valve of the fuel loading and unloading system of the nuclear first-stage top-mounted high-temperature gas-cooled reactor of the utility model adopts a multi-layer shaft seal and a fixed ball structure to ensure that its external leakage rate is less than or equal to 1×10 ^-6 Pa·m ³ /s under the condition of helium Leakage rate ≤1×10 ^-3 Pa·m ³ /s nuclear primary ball valve.

Claims (7)

1 A ball valve for nuclear first-level top-mounted high-temperature gas-cooled reactor fuel loading and unloading system, including valve body, valve cover, electric drive device, valve stem, ball, valve seat and other core components, characterized in that: the upper half of the ball valve and its top It is the bonnet, under the bonnet is the electric drive device; the bottom of the lower half of the ball valve is a sleeve-type valve seat, the ball is embedded in the center of the sleeve-type valve seat, and the inlet sealing structure is assembled between the ball and the sleeve-type valve seat; the sleeve The upper part of the valve seat is equipped with a stem sealing structure; the upper part of the ball valve is installed on the lower part of the ball valve from top to bottom. 2. According to claim 1, the ball valve of nuclear first-stage top-loading high-temperature gas-cooled reactor fuel handling system is characterized in that: the sealing structure of the valve stem is a sealing mechanism composed of a gasket, an O-ring, an upper packing, and a lower packing. 3 According to claim 2, the ball valve of the first-stage nuclear top-loading high-temperature gas-cooled reactor fuel loading and unloading system is characterized in that: a packing spacer is placed between the upper packing and the lower packing, and an intermediate leakage device is installed. 4. According to claim 2, the ball valve of nuclear first-stage top-mounted high-temperature gas-cooled reactor fuel loading and unloading system is characterized in that: the packing gland is pressed on the top packing, and the packing gland is pressed by a disc spring group. 5. According to claim 1, the ball valve of nuclear first-stage top-mounted high-temperature gas-cooled reactor fuel loading and unloading system is characterized in that: the opening and closing of the ball adopts a double positioning structure. A mechanical limit device-limit plate is specially set up. 6. According to claim 1, the ball valve of nuclear first-stage top-mounted high-temperature gas-cooled reactor fuel loading and unloading system is characterized in that: the sleeve-type valve seat, the adjustment pad adjacent to the valve seat can be rotated until its protruding part is embedded in the valve seat With the vacancy of the shoulder, the valve seat can retreat away from the ball, and the ball can be taken out from the valve body. 7. According to claim 1, the ball valve of the first-level nuclear top-mounted high-temperature gas-cooled reactor fuel handling system is characterized in that: the seal pretightening specific pressure loading of the inlet sealing structure is placed in the spring retaining ring to exert pressure on the shoulder of the valve seat Composed of multiple cylindrical helical compression springs.

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