Self-operated pressure regulating valve for nuclear power plant

Abstract

The self-operated pressure regulating valve comprises a valve body, a valve rod, an executing mechanism and an elastic mechanism, the valve body is provided with a first flow channel and a second flow channel, a valve seat is arranged in the valve body and located between the first flow channel and the second flow channel, and the valve seat is provided with a first through groove and a second through groove which are communicated with each other from top to bottom; the size of the cross section of the first through groove is larger than that of the cross section of the second through groove; the executing mechanism comprises a shell, a top cover and a diaphragm, the top cover is located in the shell, the diaphragm is installed in the shell, an inner cavity of the shell is divided into an upper cavity and a lower cavity by the diaphragm, and part of the structure of the diaphragm is located on the upper surface of the top cover; the upper end of the valve rod is connected with the top cover, and the lower end of the valve rod is provided with a valve element used for being matched with the first through groove of the valve seat. The elastic mechanism is used for being connected with a valve rod. The self-operated pressure regulating valve for the nuclear power plant can effectively prevent frequent contact and collision between the valve core and the valve seat or reduce the collision strength, so that the self-operated pressure regulating valve for the nuclear power plant can adapt to a small-flow working condition.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power, in particular to a self-operated pressure regulating valve for a nuclear power plant. Background Art

[0002] The self-operated pressure regulating valve often has internal leakage problems, which leads to overpressure or low pressure in the downstream equipment, affecting the safe and stable operation of the unit. The main reason is that during the overhaul period, the nitrogen consumption downstream of the valve was large, and the downstream pressure fluctuated frequently, which caused the sealing surfaces of the valve core and valve seat of the self-operated pressure regulating valve to frequently collide, thereby causing damage to the sealing surfaces of the valve core and valve seat. During daily operations, due to damage to the sealing surfaces of the valve core and valve seat, the valve leaked, causing the downstream pressure to be stable within the set pressure range, and overpressure to occur downstream. Analysis shows that the main reason for the frequent collisions between the valve core and the valve seat sealing surface is: in order to meet the maximum flow demand, the self-operated pressure regulating valve is selected to be larger. However, during the overhaul period, the gas consumption was less than the maximum flow, causing the valve core to be frequently opened and closed during pressure regulation, resulting in damage to the valve core and valve seat sealing surface. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a self-operated pressure regulating valve for a nuclear power plant to solve the problem of damage to the valve core and valve seat sealing surface of the self-operated pressure regulating valve in the related art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: construct a self-operated pressure regulating valve for a nuclear power plant, including a valve body, a valve stem, an actuator and an elastic mechanism, the valve body having a first flow channel and a second flow channel, a valve seat being arranged between the first flow channel and the second flow channel in the valve body, the valve seat being respectively provided with a first through groove and a second through groove which are interconnected from top to bottom, the cross-sectional dimension of the first through groove being larger than the cross-sectional dimension of the second through groove;

[0005] The actuator comprises a shell, a top cover and a diaphragm, wherein the top cover is located in the shell, the diaphragm is installed in the shell, the diaphragm divides the inner cavity of the shell into an upper chamber and a lower chamber, and a part of the structure of the diaphragm is located on the upper surface of the top cover;

[0006] The upper end of the valve stem is connected to the top cover, and the lower end of the valve stem is provided with a valve core for matching with the first through groove of the valve seat;

[0007] The elastic mechanism is used to be connected with the valve stem.

[0008] In some embodiments, a plurality of soft seals are provided on the bottom surface of the valve core.

[0009] In some embodiments, a sealing groove is provided on the bottom surface of the valve core, and the soft sealing member is provided in the sealing groove.

[0010] In some embodiments, the upper side of the valve body is provided with a mounting groove;

[0011] The self-operated pressure regulating valve of the nuclear power plant further comprises a valve cover assembly, the valve cover assembly comprises a valve cover and a gland, the valve cover comprises a tubular cover body, an annular convex portion extends outwardly from the lower end of the cover body, the gland is sleeved on the outer periphery of the cover body and the gland is connected to the valve body to restrict the annular convex portion in the mounting groove;

[0012] The valve stem is penetrated through the cover body.

[0013] In some embodiments, an annular limiting portion extends inwardly from the middle of the cover body, and the space above the annular limiting portion of the cover body forms a sealed cavity, in which a sealing component is provided that is sleeved on the outer periphery of the valve stem.

[0014] In some embodiments, the valve cover assembly also includes a sealing cover, which is sleeved on the outer periphery of the valve stem, and the sealing cover includes an annular portion and an abutment portion extending from one side of the annular portion, the annular portion is connected to the upper side surface of the cover body, and the abutment portion extends into the sealing cavity to fix the sealing component.

[0015] In some embodiments, the valve cover assembly further includes a guide sleeve, which includes an annular fixing portion and a sleeve body connected to the fixing portion, the fixing portion is restricted on the bottom wall of the mounting groove by the annular protrusion, and the sleeve body is used for the valve stem to pass through.

[0016] In some embodiments, a sealing ring is provided on the bottom surface of the valve stem.

[0017] In some embodiments, the elastic mechanism includes a pressure regulating disk, a spring seat and a spring, the pressure regulating disk is connected to the outer side of the cover body, the spring seat is connected to the partial structure of the valve stem located on the outside of the cover body, the spring is sleeved on the outer periphery of the valve stem, and the two ends of the spring respectively abut the pressure regulating disk and the spring seat.

[0018] In some embodiments, the actuator further comprises a base connected to the lower surface of the housing, and the base is connected to the gland via a column.

[0019] The implementation of the present invention has the following beneficial effects: the self-operated pressure regulating valve of a nuclear power plant can effectively prevent the valve core from frequently contacting and colliding with the valve seat, or reduce the intensity of the collision, so that the self-operated pressure regulating valve of a nuclear power plant can adapt to small flow conditions. The overall service life of the self-operated pressure regulating valve of a nuclear power plant can be increased, and the operating cost of the nuclear power plant can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work. In the drawings:

[0021] Figure 1 It is a structural schematic diagram of a self-operated pressure regulating valve for a nuclear power plant in some embodiments of the present invention;

[0022] Figure 2 It is a schematic diagram of some structural details of a self-operated pressure regulating valve for a nuclear power plant in some embodiments of the present invention. DETAILED DESCRIPTION

[0023] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0024] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0025] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0026] See also Figure 1 to Figure 2 The present invention shows a self-operated pressure regulating valve for a nuclear power plant, which can meet the use requirements of small flow conditions and avoid the self-operated pressure regulating valve for a nuclear power plant from frequently opening and closing and damaging the sealing surface between the valve core 50 and the valve seat 13.

[0027] The self-operated pressure regulating valve for a nuclear power plant comprises a valve body 10 , a valve stem 20 , an actuator 30 and an elastic mechanism 40 .

[0028] The valve body 10 has a first flow channel 11 and a second flow channel 12. The first flow channel 11 can be used to connect an upstream pipeline, and the second flow channel 12 can be used to connect a downstream pipeline. A valve seat 13 is provided between the first flow channel 11 and the second flow channel 12 in the valve body 10. The valve seat 13 can be fixed to the inside of the valve body 10 by fasteners such as bolts. The valve seat 13 is provided with a first through groove 131 and a second through groove 132 that are interconnected from top to bottom. The cross-sectional dimension of the first through groove 131 is larger than the cross-sectional dimension of the second through groove 132, and the bottom surface of the first through groove 131 can form a sealing surface, such as Figure 2 As shown, when the first through groove 131 and the second through groove 132 are substantially cylindrical grooves, the inner diameter of the first through groove 131 is greater than the inner diameter of the second through groove 132. In addition, a sealing gasket 15 may be provided on the bottom surface of the valve seat 13 to improve the sealing performance. The sealing gasket 15 may be a fluororubber gasket or other sealing gaskets, which are not specifically limited here.

[0029] The actuator 30 includes a housing 31, a top cover 32 and a diaphragm 33. The top cover 32 is located in the housing 31. The diaphragm 33 is installed in the housing 31. The diaphragm 33 divides the inner cavity of the housing 31 into an upper chamber 30a and a lower chamber 30b, and part of the structure of the diaphragm 33 is located on the upper surface of the top cover 32. The housing 31 is also provided with a pressure-taking hole 311 connected to the upper chamber 30a. The pressure-taking hole 311 is connected to the downstream pipeline of the self-operated pressure regulating valve of the nuclear power plant through a pressure-conducting pipe. Furthermore, the pressure-taking port 311 is connected to the downstream pipeline through a pressure-conducting pipe and a stop valve.

[0030] The upper end of the valve stem 20 is connected to the top cover 32, and the lower end of the valve stem 20 is provided with a valve core 50 for matching with the first through groove 131 of the valve seat 13. The valve core 50 may be substantially cylindrical, and the diameter of the valve core 50 is close to the inner diameter of the first through groove 131. The valve core 50 and the valve seat 13 are combined into a sealing structure. The elastic mechanism 40 is used to connect with the valve stem 20 to provide spring force to the valve stem 20.

[0031] The valve seat 13 is provided with the first through groove 131 and the second through groove 132, and the first through groove 131 serves as a buffer zone. When the valve core 50 is closed, before contacting the sealing surface of the valve seat 13, the valve core 50 first enters the cylindrical first through groove 131. At this time, the self-operated pressure regulating valve of the nuclear power plant is almost in a closed state, and the pressure difference on both sides of the sealing surface of the valve core 50 will increase suddenly, providing a sudden increase in resistance for closing the valve, thereby preventing the valve core 50 from frequently contacting and colliding with the valve seat 13, or reducing the intensity of the collision. It can be understood that the self-operated pressure regulating valve of the nuclear power plant can effectively prevent the valve core 50 from frequently contacting and colliding with the valve seat 13, or reduce the intensity of the collision, so that the self-operated pressure regulating valve of the nuclear power plant can adapt to small flow conditions. And it can increase the overall service life of the self-operated pressure regulating valve of the nuclear power plant and reduce the operating cost of the nuclear power plant.

[0032] In some embodiments, the bottom surface of the valve core 50 is provided with a plurality of soft seals 51. Furthermore, the bottom surface of the valve core 50 is provided with a sealing groove, and the soft seal 51 is provided in the sealing groove. The sealing groove may be an annular groove, and the soft seal 51 is an annular structure. The soft seal 51 may include but is not limited to fluororubber. The valve core 50 is added with a soft seal 51, for example, a soft seal material such as fluororubber is embedded therein, so as to achieve a buffering effect when the valve core 50 is closed and contacts the valve seat 13, thereby avoiding collision and damage between the valve core 50 and the valve seat 13 (which is a metal hard seal). Of course, the material and size of the soft seal 51 can also be selected according to actual needs, and are not specifically limited here.

[0033] In some embodiments, the upper side of the valve body 10 is provided with a mounting groove 14; the self-operated pressure regulating valve of the nuclear power plant further comprises a valve cover assembly 60, the valve cover assembly 60 comprises a valve cover 61 and a gland 62, the valve cover 61 comprises a tubular cover body 611, the lower end of the cover body 611 extends outwardly with an annular convex portion 612, the gland 62 is sleeved on the outer periphery of the cover body 611 and the gland 62 is connected to the valve body 10 to limit the annular convex portion 612 in the mounting groove 14; the valve stem 20 is passed through the cover body 611. Preferably, the gland 62 can be connected to the valve body 10 through a fixing member, and the fixing member includes but is not limited to bolts or screws.

[0034] Preferably, the mounting groove 14 may include a first sub-mounting groove and a second sub-mounting groove, and the first sub-mounting groove and the second sub-mounting groove are connected from top to bottom, and the first sub-mounting groove and the second sub-mounting groove may both be cylindrical grooves, and the inner diameter of the first sub-mounting groove is larger than the inner diameter of the second sub-mounting groove, so that the bottom wall of the first sub-mounting groove forms a bearing wall, and the annular protrusion 612 may be abutted and limited on the bearing wall.

[0035] In some embodiments, an annular stopper 613 extends inward from the middle of the cover 611, and the space above the annular stopper 613 of the cover 611 forms a sealed cavity, in which a sealing component 63 sleeved on the outer periphery of the valve stem 20 is provided. The sealing component 63 can be a fluororubber ring or a fluororubber sleeve or other sealing materials, which are not specifically limited here.

[0036] In some embodiments, the valve cover assembly 60 further includes a sealing cover 64, which is sleeved on the outer periphery of the valve stem 20, and includes an annular portion 641 and an abutting portion 642 extending from one side of the annular portion 641. The annular portion 641 is connected to the upper side of the cover body 611 by, for example, a threaded connection, and the abutting portion 642 extends into the sealing cavity to fix the sealing component 63. The inner wall surface and the outer wall surface of the abutting portion 642 may be provided with a sealing member, which includes but is not limited to a sealing ring such as a fluororubber sealing ring, so as to improve the sealing between the valve cover 61 and the valve stem 20. Of course, the sealing member may also be a soft metal sealing member, which is not specifically limited here.

[0037] In some embodiments, the valve cover assembly 60 further includes a guide sleeve 65, the guide sleeve 65 includes an annular fixing portion 651 and a sleeve body 652 connected to the fixing portion 651, the fixing portion 651 is limited on the bottom wall of the mounting groove 14 by the annular protrusion 612, and the sleeve body 652 is used for the valve stem 20 to pass through. Preferably, the fixing portion 651 is located on the bearing wall and is abutted and limited by the annular protrusion 612, while the sleeve body 652 extends into the inner cavity of the second sub-mounting groove, and the inner diameter of the inner cavity of the sleeve body 652 is similar to the diameter of the portion of the valve stem 20 passing through the sleeve body 652, which can prevent the valve stem 20 from being displaced when moving up and down in the height direction, and improve the centering of the valve stem 20.

[0038] In some embodiments, a sealing ring 21 is provided on the bottom surface of the valve stem 20 to improve the sealing performance. Preferably, the valve core 50 and the axial end surface of the valve stem 20 can be connected by a fastener, which includes but is not limited to a fastening bolt or a fastening screw.

[0039] In some embodiments, the elastic mechanism 40 includes a pressure regulating disk 41, a spring seat 42 and a spring 43, the pressure regulating disk 41 is connected to the outer side of the cover body 611, the spring seat 42 is connected to the partial structure of the valve stem 20 located outside the cover body 611, the spring 43 is sleeved on the outer periphery of the valve stem 20, and the two ends of the spring 43 are respectively against the pressure regulating disk 41 and the spring seat 42, and the elastic mechanism 40 can provide spring force for the valve stem 20. The spring 43 can include but is not limited to a spiral columnar spring.

[0040] In some embodiments, the actuator 30 further includes a base 34 connected to the lower surface of the housing 31 , and the base 34 is connected to the gland 62 via a column 70 , and a plurality of columns 70 may be provided to improve connection stability.

[0041] The self-operated pressure regulating valve of a nuclear power plant is used to control the pressure after the valve. The action mode of the self-operated pressure regulating valve of a nuclear power plant is a pressure-closing type. The principle of the self-operated pressure regulating valve of a nuclear power plant is as follows: the medium flows through the valve body 10 from the upstream pipeline of the valve body 10, and the position of the valve core 50 (i.e., the cross-flow area between the valve core 50 and the valve seat 13) determines the medium flow rate. The controlled downstream pressure is transmitted to the actuator 30 through the pressure pipe and the stop valve to act on the diaphragm 33, forming a positioning force of the valve core 50. The positioning force adjusts the position of the valve core 50 according to the size of the spring force. The size of the spring force is adjusted by the pressure regulating disk 41. When the pressure after the valve is greater than the adjusted set point, the diaphragm 33 will drive the top cover 32 to descend, and then drive the valve stem 20 to move downward, the spring seat 42 compresses the spring 43, and drives the valve core 50 to descend. The opening of the self-operated pressure regulating valve of a nuclear power plant is reduced in proportion to the pressure change. When the pressure after the valve is lower than the set point, the reaction force generated by the spring 43 drives the valve core 50 to move upward, so that the opening of the self-operated pressure regulating valve of the nuclear power plant increases according to the pressure change, thereby achieving the purpose of reducing pressure and stabilizing pressure.

[0042] The self-operated pressure regulating valve of a nuclear power plant has the following beneficial effects: the valve seat of the self-operated pressure regulating valve in the related art is not provided with the first through groove 131 and the second through groove 132, and it will be directly closed when the flow rate is small, while the self-operated pressure regulating valve of a nuclear power plant of the present invention is provided with the first through groove 131 and the second through groove 132, and the valve core 50 will not be completely closed when in contact with the first through groove 131, so the regulating performance under small flow conditions is also very good, and it can effectively adapt to small flow conditions.

[0043] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the scope covered by the claims of the present invention.

Claims

1. A self-operated pressure regulating valve for a nuclear power plant, characterized in that: The invention comprises a valve body (10), a valve stem (20), an actuator (30) and an elastic mechanism (40); the valve body (10) has a first flow channel (11) and a second flow channel (12); a valve seat (13) is provided in the valve body (10) between the first flow channel (11) and the second flow channel (12); the valve seat (13) is provided with a first through groove (131) and a second through groove (132) which are interconnected from top to bottom; the cross-sectional dimension of the first through groove (131) is greater than the cross-sectional dimension of the second through groove (132); The actuator (30) comprises a housing (31), a top cover (32) and a diaphragm (33), wherein the top cover (32) is located in the housing (31), the diaphragm (33) is installed in the housing (31), the diaphragm (33) divides the inner cavity of the housing (31) into an upper chamber (30a) and a lower chamber (30b), and a part of the structure of the diaphragm (33) is located on the upper surface of the top cover (32); The upper end of the valve stem (20) is connected to the top cover (32), and the lower end of the valve stem (20) is provided with a valve core (50) for matching with the first through groove (131) of the valve seat (13); The elastic mechanism (40) is used to be connected to the valve stem (20).

2. The self-operated pressure regulating valve for nuclear power plant according to claim 1, characterized in that: A plurality of soft sealing components (51) are provided on the bottom surface of the valve core (50).

3. The self-operated pressure regulating valve for nuclear power plants according to claim 2, characterized in that: The bottom surface of the valve core (50) is provided with a sealing groove, and the soft sealing member (51) is provided in the sealing groove.

4. The self-operated pressure regulating valve for nuclear power plant according to claim 1, characterized in that: The upper side of the valve body (10) is provided with a mounting groove (14); The self-operated pressure regulating valve for a nuclear power plant further comprises a valve cover assembly (60), wherein the valve cover assembly (60) comprises a valve cover (61) and a gland (62), wherein the valve cover (61) comprises a tubular cover body (611), wherein an annular convex portion (612) extends outwardly from the lower end of the cover body (611), and the gland (62) is sleeved on the outer periphery of the cover body (611) and connected to the valve body (10) to restrict the annular convex portion (612) within the mounting groove (14); The valve stem (20) is inserted into the cover body (611).

5. The self-operated pressure regulating valve for nuclear power plants according to claim 4, characterized in that: An annular limiting portion (613) extends inward from the middle of the cover body (611), and a sealed cavity is formed in the space above the cover body (611) and above the annular limiting portion (613). A sealing component (63) is provided in the sealed cavity and is sleeved on the outer periphery of the valve stem (20).

6. The self-operated pressure regulating valve for nuclear power plant according to claim 5, characterized in that: The valve cover assembly (60) also includes a sealing cover (64), which is sleeved on the outer periphery of the valve stem (20), and the sealing cover (64) includes an annular portion (641) and an abutment portion (642) extending from one side of the annular portion (641), wherein the annular portion (641) is connected to the upper side surface of the cover body (611), and the abutment portion (642) extends into the sealing cavity to fix the sealing component (63).

7. The self-operated pressure regulating valve for nuclear power plants according to claim 6, characterized in that: The valve cover assembly (60) also includes a guide sleeve (65), which includes an annular fixing portion (651) and a sleeve body (652) connected to the fixing portion (651), wherein the fixing portion (651) is restricted on the bottom wall of the mounting groove (14) by the annular protrusion (612), and the sleeve body (652) is used for allowing the valve stem (20) to pass through.

8. The self-operated pressure regulating valve for nuclear power plant according to claim 1, characterized in that: A sealing ring (21) is provided on the bottom surface of the valve stem (20).

9. The self-operated pressure regulating valve for nuclear power plant according to claim 4, characterized in that: The elastic mechanism (40) comprises a pressure regulating disk (41), a spring seat (42) and a spring (43); the pressure regulating disk (41) is connected to the outer side surface of the cover body (611); the spring seat (42) is connected to a partial structure of the valve stem (20) located on the outer side of the cover body (611); the spring (43) is sleeved on the outer periphery of the valve stem (20), and the two ends of the spring (43) respectively abut against the pressure regulating disk (41) and the spring seat (42).

10. The self-operated pressure regulating valve for nuclear power plant according to claim 4, characterized in that: The actuator (30) further comprises a base (34) connected to the lower surface of the housing (31), and the base (34) is connected to the gland (62) via a column (70).

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