CN216951683U - Drainage pneumatic stop valve for power station - Google Patents

Abstract

The utility model relates to a drainage pneumatic stop valve for a power station, which comprises a valve body, wherein a vertical valve cavity is arranged in the valve body, a valve seat and an upper sealing valve seat are arranged in the valve cavity, the valve seat is positioned between a middle cavity and a lower cavity, the upper sealing valve seat is positioned between the upper cavity and the middle cavity, the sealing surface of the valve seat faces upwards, the sealing surface of the upper sealing valve seat faces downwards and respectively forms a valve seal and an upper seal with a lower sealing surface and an upper sealing surface of a valve core, the valve core is positioned in the middle cavity and is in sliding fit with the middle cavity, a valve rod penetrates through the upper cavity, the lower end of the valve rod is connected with the valve core, the upper end of the valve rod is positioned outside the valve body and is used for connecting a driving device, a medium inlet channel of the valve is communicated with the middle cavity, a medium outlet channel of the valve is communicated with the lower cavity, and an anti-scouring throttling sleeve can be arranged in a reducing through hole of the valve body. The utility model has the characteristics of reliable sealing, wear resistance, erosion resistance, simple structure, convenient installation, long service life, convenient field maintenance and the like.

Description

Drainage pneumatic stop valve for power station

Technical Field

The utility model relates to a pneumatic stop valve, in particular to a drainage pneumatic stop valve for a subcritical unit and a supercritical unit of a power station and a high-efficiency supercritical power station, which can be applied to water and steam occasions such as drainage of a main steam pipeline of a steam turbine of a power enterprise, steam exhaust, shutdown of a feed water heater, a drain valve of a boiler, a drain valve of an economizer, a feed water recycling bypass isolation valve of the boiler, a feed water shutdown valve of the boiler, a drain valve of a steam pocket, a regular blowdown valve of the boiler and the like.

Background

From the 80 s of the 20 th century, the domestic main power station main engine and auxiliary engine manufacturing industry successively introduced foreign advanced design technology and manufacturing technology to meet the needs of domestic large-scale power station unit development. Up to now, the main and auxiliary equipments of the subcritical supercritical power plant unit of large power station have been substantially localized, including the important main and auxiliary equipments of 660MW and 1000MW high-efficiency supercritical power plant unit.

In recent years, large-scale power stations develop rapidly, the valve manufacturing industry in China does not follow the development rhythm of power station installation, and most of domestic high-end valves still depend on import. China still has the defects of relatively laggard technology, unstable reliability, complex manufacturing process, difficulty in maintenance and the like of high-end valves, and needs to invest relatively large manpower and maintenance time.

At present, be equipped with in the valve body of domestic pneumatic stop valve disk seat structure and with the case, disk seat and case constitute valve seal pair, and the case is connected with the valve rod, and pneumatic means can drive the valve rod and reciprocate, and then drives the valve and open or turn-off, when being used for high pressure high temperature occasion, often shows that precision and quality grade are not high, wherein mainly have following some structural reasons: the sealing surface adopts surface contact, and the sealing is not tight when the sealing device is used in a high-pressure occasion; the valve core adopts a hook type, and the valve rod of the valve core is positioned at a different position; the sealing surface is easy to erode, and the valve core guiding part is easy to wear.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects in the prior art, the utility model provides the drainage pneumatic stop valve for the power station, which has the characteristics of reliable sealing, wear resistance, erosion resistance, simple structure, convenience in installation, long service life, convenience in field maintenance and the like.

The technical scheme adopted by the utility model is as follows:

a power station drainage pneumatic stop valve comprises a valve body, wherein a vertical valve cavity is arranged in the valve body, a valve seat (or called valve seat or main valve seat) and an upper sealing valve seat are arranged in the valve cavity, the valve seat and the upper sealing valve seat divide the valve cavity into an upper cavity, a middle cavity and a lower cavity, the valve seat is positioned between the middle cavity and the lower cavity (the boundary part of the middle cavity and the lower cavity), the sealing surface of the valve seat faces upwards, the sealing surface of the upper sealing valve seat faces downwards and respectively forms a valve seal and an upper seal with the lower sealing surface and the upper sealing surface of the valve core, the valve core is positioned in the middle cavity and is in sliding (axial sliding) fit with the middle cavity, the valve rod penetrates through the upper cavity, the lower end of the valve core is connected with the valve core, the upper end of the valve core is positioned outside the valve body and is used for connecting a driving device, a medium inlet channel of the valve (or the valve body) is communicated with the middle cavity, and a medium outlet channel of the valve is communicated with the lower cavity. When the valve core moves downwards to seal the lower sealing surface of the valve core with the sealing surface of the valve seat, the medium channel from the middle cavity to the lower cavity is cut off, the valve is closed, when the valve core moves upwards to seal the lower sealing surface of the valve core away from the sealing surface of the valve seat and seal the upper sealing surface of the valve core with the sealing surface of the upper sealing valve seat, the valve is in a fully-opened state, the medium channel from the middle cavity to the upper cavity is cut off, and the medium cannot flow into the upper cavity.

Can adopt prior art to realize the sealing between valve rod and the valve body for the packing of valve rod seal is filled between the inner wall of valve rod and epicoele, and the top of packing can be equipped with gland, reveals from the clearance between valve rod and the valve body in order to prevent to flow into the medium of lumen.

The bottom of the lower cavity is closed, and the medium flowing into the lower cavity can only flow out of the medium outlet channel of the valve.

The upper sealing valve seat and the sealing structure of the valve core and the upper sealing valve seat can adopt any suitable existing valve sealing technology.

Other configurations of the valve may be any suitable known technique.

A power station drainage pneumatic stop valve comprises a valve body, wherein the valve body is provided with a vertical reducing round hole (a hole with a circular cross section), the reducing round hole is a blind hole with an open upper end, the aperture of the upper section of the reducing round hole is larger than that of the lower section of the reducing round hole, a reducing part between the upper section and the lower section of the reducing round hole is a valve seat (or a valve seat or a main valve seat), the corresponding part can be set into a valve seat structure to form the valve seat (for example, machining is carried out after surfacing of a valve seat material at the corresponding part), a tubular throttling sleeve (or an anti-scouring throttling sleeve) is arranged in the reducing round hole, the throttling sleeve is positioned at the lower part of the upper section of the reducing round hole, the bottom surface of the throttling sleeve is abutted against the reducing end surface of the reducing round hole (on the reducing end surface between the upper section and the lower section), the outer side surface of the throttling sleeve is matched with the inner wall of the upper section of the reducing round hole to realize the fixation of the throttling sleeve in each plane direction, the inner diameter of the throttling sleeve is larger than the diameter of the lower section of the reducing round hole, so that the inner edge part of a reducing end face between the upper section and the lower section of the reducing round hole is exposed from the inner side (radial inner side) of the inner wall of the throttling sleeve to be provided with a valve seat sealing face matched with a corresponding sealing face at the bottom of the valve core, an expansion section (or called diameter expansion section or expansion section) is further arranged in the reducing round hole, the expansion section is axially positioned between the upper end and the lower end of the throttling sleeve (the upper end is lower than the upper end of the throttling sleeve, the lower end is higher than the lower end of the throttling sleeve), the diameter of the expansion section is larger than the outer diameter of the throttling sleeve, so that an annular gap allowing a medium to flow through is reserved between the inner wall of the expansion section and the throttling sleeve (the outer side face of the throttling sleeve), and a throttling hole (or called throttling through hole) which is communicated with the radial direction of the annular gap (the central axis of the hole is radial direction) is arranged on the side wall of the throttling sleeve, the inner end of a medium inlet channel of the valve body is communicated with the annular gap (or is arranged on the outer wall of the annular gap), the inner end of a medium outlet channel of the valve body is communicated with the lower part of the lower section of the diameter-variable round hole (or is arranged on the lower hole wall of the lower section of the diameter-variable round hole), a valve core (or called valve clack) is arranged in the throttling sleeve, the valve core is in a shape of a revolution (basic shape), is in a waist shape and is provided with a top surface and a bottom surface, the upper part and the lower part of the side surface of the valve core are respectively provided with an upper flange protruding outwards in the radial direction and a lower flange protruding outwards in the radial direction, so that the valve core is in the waist shape, the outer side surface of the upper flange and the outer side surface of the lower flange are both preferably cylindrical surfaces, the main body part (namely the middle part of the valve core) of the outer side surface of the valve core between the upper flange and the lower flange is preferably cylindrical, the outer side surface of the upper flange and the outer side surface of the lower flange are cylindrical surfaces and the cylindrical surfaces of the upper flange and the lower flange have the same diameters, the valve rod is in sliding fit with the inner wall of the throttling sleeve (a matching mode allowing relative sliding, or called axial guiding fit, usually a tiny matching clearance is not provided), an inner flange protruding inwards in the radial direction is arranged at the top opening of the throttling sleeve, sealing surfaces matched with each other are respectively arranged at the top of the valve seat and the bottom of the valve core and used for forming valve sealing, sealing surfaces matched with each other are respectively arranged at the bottom of the inner flange and the top of the valve core and used for forming upper sealing, a packing gland is arranged at the top of the reducing circular hole, the valve rod penetrates through the top opening of the throttling sleeve and a middle hole of the packing gland, the lower end of the valve rod is connected with the valve core, the upper end of the valve rod is located outside the valve body and used for connecting a driving device, a packing chamber used for sealing the valve rod is located between the valve rod and the inner wall of the reducing circular hole in the radial direction and is axially located between the throttling sleeve and the packing gland, the packing chamber is filled with packing for sealing or provided with a sealing element. The degree of compression of the packing gland against the sealing material can be adjusted to achieve an effective seal and allow the valve stem to rotate.

Preferably, the valve core is provided with a valve rod blind hole with an open upper end, the lower end of the valve rod extends into the valve rod blind hole, an annular pin (or called a circular pin, the shape of which is annular in a use state) for connecting the valve rod in the valve rod blind hole and the inner wall of the blind hole is arranged between the valve rod in the valve rod blind hole and the inner wall of the blind hole, and annular grooves corresponding to each other are respectively arranged on the outer side surface of the valve rod in the valve rod blind hole and the inner wall of the blind hole and used for embedding the annular pin.

Preferably, the lower end surface of the valve stem is a convex surface of revolution, for example, a spherical crown surface.

The bottom surface of the valve rod blind hole can be a horizontal plane.

Preferably, the bottom surface of the packing gland is a plane, is positioned in the reducing circular hole and is in close contact with the top of the packing so as to moderately compress the packing.

Preferably, the packing gland is in a shape of a rotor, an annular flange which protrudes outward in the radial direction is arranged at the upper part of the outer side surface of the packing gland, the top surface of the annular flange is in an umbrella shape (or called conical surface), the outer side surface of the annular flange is preferably a cylindrical surface, a pressure plate (or called packing pressure plate) is arranged above the packing gland, a conical concave surface corresponding to the top surface of the annular flange is arranged at the bottom of the pressure plate and presses on the top surface of the annular flange, two mounting lugs symmetrically extend outwards from two sides of the pressure plate (two sides in any straight line direction which is perpendicular to the axis of the reducing circular hole), and a rectangular notch which is opened at the center of the outer end is arranged on each mounting lug. During assembly, a pressing plate fastening bolt can be adopted to penetrate through the rectangular notch on the corresponding side and be fastened on the valve cover of the valve body, and the head or the top nut of the pressing plate fastening bolt is pressed on the mounting lug.

The pressure plate is provided with a middle hole for passing through the valve rod, and the diameter of the middle hole of the pressure plate can be equal to or larger than that of the middle hole of the packing gland.

The valve cover can be screwed or fixedly installed on the top opening of the valve body in other modes (such as bolt fastening), two bolt connecting lugs are symmetrically arranged on two sides (two sides in any straight line direction perpendicular to the axis of the diameter-variable round hole) of the valve cover, the pressure plate fastening bolt is a loose joint bolt, and the loose joint bolt is hinged to the bolt connecting lugs on the corresponding side through a pin shaft.

Preferably, the packing gland adopts a two-split structure and is formed by folding two gland half bodies which are in mirror symmetry relative to any longitudinal section (any plane passing through the axis of the reducing circular hole). The integral gland can be processed firstly, and then the gland is cut into two symmetrical half bodies along any longitudinal section by the modes of linear cutting and the like.

Preferably, the sealing surface of the top of the valve seat and the sealing surface of the bottom of the valve element are both conical (frustum-shaped).

Preferably, an inner edge (radially inner edge) of the sealing surface of the bottom of the valve element is located radially inside an inner edge of the sealing surface of the top of the valve seat, an outer edge (radially outer edge) is located radially outside an outer edge of the sealing surface of the top of the valve seat, and a taper angle of the sealing surface of the bottom of the valve element is greater (slightly greater) than a taper angle of the sealing surface of the top of the valve seat.

Preferably, the sealing surface at the bottom of the inner flange may be a conical surface with a small top and a large bottom, an inner edge (radial inner edge) of the sealing surface is connected to the horizontal bottom surface of the inner flange, an outer edge (radial outer edge) of the sealing surface is connected to the cylindrical inner side surface of the throttle sleeve, and the sealing surface at the top of the valve core may be a convex rotating curved surface, and a generatrix of the convex rotating curved surface may be an arc (e.g., a 90 ° arc) or other suitable curve.

The valve body is preferably a die forging valve body and comprises a filling chamber space positioned at the upper part of the valve cavity and a valve seat positioned at the lower part of the valve cavity, and the threads, the seam allowance positioning, the filling chamber and the valve seat of the valve body are clamped and processed at one time. The valve rod is preferably a die forging valve cover, the lower end of the valve rod is provided with threads and an inner spigot which are matched with the threads of the valve body and the outer spigot respectively so as to automatically center and align, and the upper end of the valve rod is provided with a transition section and a spigot which is connected with a pneumatic actuating device of the valve.

The two sides of the valve cover are provided with lug ends (which can be called as bolt connection lugs), the lug ends are provided with pin holes which are matched with the loose joint bolts, and the loose joint bolts are hinged on the valve cover through pin shafts penetrating through the pin holes.

2 throttling holes are uniformly distributed in the radial direction of the anti-impact throttling sleeve, the top of an inner hole of the throttling sleeve is provided with a reverse sealing taper angle sealed with the valve core, and a conical surface with a taper angle of 120 degrees is formed so as to be sealed with the R at the upper end of the valve core; the inner hole of the anti-impact throttling sleeve is connected with a shaft shoulder (radial flange) of the valve core in a guiding mode, and the top of the inner hole is of a necking down (inner flange) structure to form a smaller inner hole connected with the valve rod in a guiding mode.

And a clearance allowing relative deflection for a certain small angle is reserved between the anti-impact throttling sleeve and the valve core (the upper radial flange and the lower radial flange of the valve core) and the valve rod.

The packing gland is composed of two symmetrical halves, is matched with the packing chamber of the valve body and is used for compressing the packing of the packing chamber; and an inner hole of the packing gland is matched with the valve rod in a guiding way.

The valve rod and the valve core are preferably connected in a tenon-and-mortise structure, the lower end of the valve rod is a tenon-shaped axial outward-extending end, a U-shaped groove matched with the axial outward-extending end in shape is formed in an inner hole of the valve core, the axial outward-extending end and the U-shaped groove are mutually inserted to form a tenon-and-mortise structure node, and a gap enough for enabling the valve core to deflect at a certain angle relative to the valve rod is reserved between the axial outward-extending end and the U-shaped groove.

The valve comprises a valve rod, a valve core and a valve core, wherein the valve rod is provided with a valve rod annular groove, the valve core is provided with a valve core annular groove matched with the valve rod annular groove, the valve core is provided with a pin hole, the pin hole is communicated with the valve core annular groove, the axis of the pin hole and the central line of the valve core annular groove are positioned on the same cross section of the valve core and are tangent, the pin hole penetrates through the single side wall of the valve core, and a round pin which basically surrounds one circle is arranged between the valve rod annular groove and the valve core annular groove through the pin hole on the valve core during assembly.

The utility model has the beneficial effects that:

1) because the reverse sealing (upper sealing) structure relative to the valve seal is arranged, the sealing function is realized at the full-open position of the valve, the pressure at the packing position of the valve is reduced, and the service life of the packing is prolonged.

2) The sealing pair adopts linear sealing, the sealing specific pressure is high, the sealing is reliable, and the sealing surface adopts cobalt-based hard alloy surfacing, so that the sealing pair is wear-resistant and erosion-resistant.

3) Due to the adoption of the integral die forging of the valve body, the flow rate is good, materials are saved, the problem of inner leakage caused by secondary sealing is solved in the built-in packing chamber and the valve body, the valve body and the valve cover are of a split structure, the inner cavity of the valve body is short, the inner diameter of the valve body is increased, the selection of a mechanical cutter is facilitated, the machining difficulty of the valve body is reduced, the problem that a deep hole is difficult to build up welding is solved, and the labor production efficiency is effectively improved.

4) Due to the adoption of the anti-impact throttling sleeve structure, the matched guide of the shaft shoulder of the valve core and the inner hole of the anti-impact throttling sleeve and the guide of the valve rod and the upper part of the anti-impact throttling sleeve are effectively ensured; the valve core and the sleeve are effectively ensured to be aligned, and the valve rod and the sleeve are aligned; the valve core and the valve rod are connected by adopting mortise and tenon joints, enough clearance is reserved, the valve core and the valve rod are in floating connection by a round pin, the valve core can have certain swinging amount relative to the valve rod, and enough adjustment amount is provided for the contact between the valve core and the sealing surface of the valve seat, so that the valve core can be automatically centered and aligned; the valve core and the valve seat of the stop valve are both contained in the throttling sleeve, so that the scouring of a medium to a sealing surface is effectively reduced, and the service lives of the valve core and the valve seat are prolonged.

5) Because the gland of packing adopts two to open the structure, after the gland takes out, need not to dismantle the valve gap, only need to drive case valve rod scour protection throttle cover, filler and take out in the lump, effective valve dismouting time.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a cross-sectional view of the packing gland and valve cover of FIG. 1;

FIG. 3 is an enlarged view of the valve core, valve seat, and anti-impingement flow sleeve of FIG. 1

FIG. 4 is a cross-sectional view of the ring pin of FIG. 3;

FIG. 5 is an enlarged view of the valve cartridge of FIG. 1 when open;

FIG. 6 is a schematic structural view of one embodiment of a packing gland;

FIG. 7 is a bottom view of FIG. 6;

FIG. 8 is a schematic structural view of one embodiment of a platen;

FIG. 9 is a bottom view of FIG. 8;

fig. 10 is an enlarged view of the valve cartridge of fig. 1 during opening.

Detailed Description

Referring to fig. 1-10, the utility model provides a supercritical hydrophobic pneumatic stop valve which can be widely applied to large-scale subcritical, supercritical and high-efficiency supercritical power station units. Including die forging's valve body 9, die forging's valve gap 3, set up in disk seat 12 in the valve body, anti-scouring throttle cover 5, with the disk seat constitutes sealed vice case 13 and the valve rod 18 that drives the straight line of case and go up and down, its the case is solid of revolution structure, and the sealed face 31 and the case guide part all build-up welding of case down with disk seat complex on the case are stellite, and the case adopts annular round pin 6 to link with the valve rod, and the head (lower terminal surface) 44 of valve rod is the arc shape, can look for the center automatically with the case assembly back, effectively prevents the washing away of fluid medium under the protection of anti-scouring throttle cover.

The valve body is integrally formed by die forging, so that the material is saved, the leakage points are few, and the quality is good, which is mainly shown in the following steps: the die forging valve body has the advantages of uniform wall thickness, high surface quality, small machining allowance, light weight, hardness, chemical components, mechanical properties and the like, and can well ensure various properties required by the valve body material. The excircle of the upper end of the valve body is provided with a thread and a spigot, and a packing chamber and a valve seat (a valve seat sealing surface) are arranged inside the valve body; the threads are machined with the inner cavity to ensure concentricity between the two. Because the valve body is provided with the anti-impact throttling sleeve, the inner cavity is large, the mechanical processing is convenient, and the welding is convenient.

The valve cover 3 adopts a die forging structure, has the advantages of high forging strength, good mechanical property, simple structure, light weight and the like, and effectively ensures various performances required by the valve cover. The lower end of the valve cover is provided with an internal thread and an internal spigot which are respectively matched with the external thread and the external spigot of the valve body, and the valve cover can automatically center; the upper end of the valve cover is provided with a spigot used for being connected with a pneumatic actuating mechanism; the ear parts (bolt connection lugs) 14 on the two sides of the valve cover are provided with pin holes, and are hinged with loose joint bolts 16 through pin shafts 15 arranged in the pin holes, so that the valve is convenient to disassemble and assemble.

Two sides of the pressure plate symmetrically extend outwards to form two mounting lugs 21, and rectangular notches 22 with openings in the centers of the outer ends are formed in the mounting lugs. During assembly, a pressure plate fastening bolt can be adopted to penetrate through the rectangular notch on the corresponding side and be fastened on the valve cover of the valve body, and a nut at the head or the top of the pressure plate fastening bolt is pressed on the mounting lug

The valve cavity is internally provided with an anti-scouring throttling sleeve 5, the throttling sleeve adopts a nitriding process, the surface hardness is as high as more than 750HV, and the anti-scouring performance is good. The outer diameter (outer side surface) of the anti-impact throttling sleeve is matched with the valve body, and the inner hole of the throttling sleeve is respectively matched with the valve core and the valve rod, so that the matching precision of the valve core and the valve seat is effectively guaranteed. Because the valve core and the valve seat are both contained in the throttling sleeve, the scouring of media to the sealing surfaces of the valve core and the valve seat is effectively reduced, and the service lives of the valve core and the valve seat are prolonged.

The vertical blind hole on the valve body and the inner hole of the throttling sleeve are mutually communicated to form a valve rod hole, the inner hole of the throttling sleeve is regarded as the valve rod hole in the corresponding area in the axial area provided with the throttling sleeve, the vertical blind hole of the valve body is the valve rod hole in the corresponding area in the axial area without the throttling sleeve, one part of the valve rod hole is used for penetrating through a valve rod, and the other part of the valve rod hole is used as a medium flow passage. The valve rod hole can be regarded as a main body part of the valve cavity, the valve rod hole is divided into an upper section, a middle section and a lower section of cylindrical holes which can be respectively called as an upper cavity, a middle cavity and a lower cavity, the middle cavity also comprises an annular gap positioned outside the throttling sleeve, the annular gap can also be regarded as a medium inlet channel and enters a pressure-equalizing buffer part of the middle cavity in the throttling sleeve, the hole diameters of the upper section and the lower section of cylindrical holes of the valve rod hole are the same, and the capacity expansion of the middle cylindrical hole is increased.

The throttling sleeve 5 is arranged in the middle of the valve rod hole and is provided with two symmetrical throttling holes 40, a medium in an annular gap outside the throttling sleeve flows into the throttling sleeve through the throttling holes, and the bottom surface of an inner flange 38 at the top of the throttling sleeve is provided with an annular conical surface 39 which is a sealing surface and is used for being matched with a sealing surface (an upper sealing surface) at the top of the valve core to form an upper sealing pair.

The valve core 13 is arranged in an inner cavity (or inner hole) of the anti-impact throttling sleeve; the packing gland is characterized in that a packing 4 is arranged between the valve rod and the side wall of the upper cavity of the valve body, the packing is arranged on the anti-impact throttling sleeve, a packing gland 2 sleeved on the valve rod is arranged above the packing, an annular flange 25 is arranged on the upper part of the outer diameter (outer side surface) of the packing gland, a rotary conical surface 26 is arranged on the top surface of the annular flange, and the packing gland is divided into a two-part structure which is divided into a left part and a right part (half bodies). The valve rod is further sleeved with a pressing plate 1, the pressing plate presses the packing gland, the bottom surface of the packing pressing plate is provided with inner rotary conical surfaces (conical concave surfaces) 28 matched with the packing gland, the two rotary conical surfaces are matched, the upper inner hole (or called upper part and lower part of inner hole) and the lower inner hole (or called upper part and middle part of inner hole) of the packing pressing plate are respectively matched with the outer diameters of the upper part and the middle part of the packing gland, packing compression is realized by the packing pressing plate and the packing pressing plate from top to bottom, the packing pressing plate is fastened through a threaded connector, the threaded connector comprises a nut 17, a gasket, a loose joint bolt 16 and a pin shaft (or called pin for short) 15, the loose joint bolt is connected to the ear part of the side end valve cover through a pin, the gasket is arranged on the packing pressing plate, the nut is arranged on the gasket, and compresses the packing through threads.

The packing gland 2 is of a revolving body structure, adopts a two-opening design, can be divided into two halves by linear cutting after the whole processing is finished, and the packing gland adopts a two-opening structure, so that after the gland is taken out, the valve cover does not need to be disassembled, and only the valve core and the valve rod are required to drive the anti-impact throttling sleeve and the packing to be taken out together, so that the disassembly and the assembly are more convenient.

The valve core is designed as follows:

1) the valve core is of a rotary body structure, two annular flanges (an upper flange 34 and a lower flange 32) are arranged at the position of the maximum diameter of the valve core from top to bottom, and the outer side faces of the two annular flanges are preferably cylindrical surfaces and play a double-guide role under the matching of the two annular flanges and the anti-impact throttling sleeve. The clearance between the two annular flanges and the inner hole of the throttling sleeve is controlled in design and processing, so that the concentricity of the valve core and the axis of the valve can be kept in the opening and closing process of the valve core, and the centering performance of the valve core is effectively ensured.

2) The axial distance between two end faces of two annular flanges of the valve core, which are farthest away, is larger than the maximum linear size of an outlet of a medium flowing out of the valve cavity, the annular conical surface at the lower end of the valve core forms a sealing surface (a lower sealing surface), and the lower sealing surface of the valve core and the sealing surface of the valve seat are both contained in the anti-impact throttling sleeve to jointly form a pressure reduction structure of the valve core, so that the scouring of the medium on the sealing surface can be effectively reduced. The specific process is as follows: when the valve core is slightly opened, the medium is subjected to primary pressure reduction through a throttling hole flow channel (flow channel I) 45 of the anti-impact throttling sleeve, then enters a flow channel 46 (flow channel II) between the valve core and the inner wall of the throttling sleeve for secondary pressure reduction, flows to a flow channel 47 (flow channel III) between a sealing surface of the valve seat and a sealing surface (lower sealing surface) of the valve core for tertiary pressure reduction, and enters the downstream (lower cavity) of the valve seat; the valve core is continuously lifted, when the opening degree of a lower flange of the valve core exceeds the lower edge of the flow channel I (the lower edge of the throttling hole), the medium flows into the throttling sleeve, a flow channel II between the valve core (the lower flange) and the inner wall of the throttling sleeve is opened, and the medium flows into the valve seat; under the decompression of the flow channel I, the minimum overflow area of the flow channel II is always smaller than that of the flow channel III, so that a medium erosion area can be effectively transferred from a sealing surface between the valve seat and the valve core to a lower flange area of the valve core, and the erosion of the sealing surface of the valve seat is effectively reduced; similarly, when the valve core is continuously opened to the full-open position, the valve core is completely contained in the anti-scouring throttling sleeve, the medium can not directly scour the sealing surface, the erosion of the sealing surface of the valve core is reduced under the double protection of the pressure reduction through the flow channel I, and the tightness of the valve and the service life of the valve are effectively ensured.

3) The valve rod is connected with the valve core in a mortise and tenon joint structure (an inserting structure), and can also be connected in other movable connection modes allowing small swing. For example, the lower end of the valve rod is a tenon-shaped axial outward-extending end, a U-shaped groove matched with the axial outward-extending end in shape is arranged in the inner hole of the valve core, the axial outward-extending end and the U-shaped groove are mutually inserted to form a tenon-and-mortise structure node, and a gap enough for enabling the valve core to deflect a certain angle relative to the valve rod is reserved between the axial outward-extending end and the U-shaped groove, so that the valve core can keep enough adjustment amount in the action.

For example, an annular groove 42 is formed in the outer diameter of the valve rod, a valve core annular groove 36 matched with the valve rod annular groove is formed in the inner hole wall of the valve core, a pin hole 37 is further formed in the valve core and communicated with the valve core annular groove, the axis of the pin hole and the central line of the valve core annular groove are located on the same cross section of the valve core and tangent to each other, the pin hole penetrates through the single side wall of the valve core, an annular pin (or called round pin) 6 is arranged between the valve rod annular groove and the valve core annular groove, the valve core and the valve rod are in floating connection through the round pin, the head of the valve rod is in an arc shape, a proper gap is formed between the outer diameter of the valve rod and the inner hole of the valve core, the valve core can have a certain swinging amount relative to the valve rod, and has a certain adjusting amount when being in contact with the sealing surface of the valve seat.

4) The upper surface of the valve core is provided with an R arc, the cross section of the R arc is 1/4 circles, an upper sealing surface 33 of the valve core is formed, an inner hole taper angle (annular conical surface) of the anti-impact throttling sleeve and the R arc form an upper sealing pair (or a reverse sealing pair), and the annular conical surface and the R arc can be machined after hard alloy is surfacing welded. In this embodiment, the hole lower limb of scour protection throttle cover is processed into the conical surface that the cone angle is 120, and this conical surface and R cambered surface constitute sealed pair on, and when the valve was in full open position, lumen pressure rose, and annular arch is pressed towards scour protection throttle cover, goes up sealed effect, and the medium pressure that the filler bore is near zero, effectively ensures the sealing of valve rod and filler position, has prolonged filler life.

5) Each sealing surface of the valve core is processed after surfacing of hard alloy, preferably cobalt-based hard alloy is surfaced, the cobalt-based hard alloy is suitable for being used as the sealing surface of the valve working under high temperature and high pressure, an EDCoCr-A-03 (D802) welding rod can be used, manual arc welding is adopted, the hardness of the surfaced sealing surface reaches more than 40HRC, and the valve core can be used in a working environment with PN less than or equal to 60Mpa and t less than or equal to 670 ℃; and using Co104 (wire 112) to carry out surfacing welding, adopting manual argon arc welding or manual oxyacetylene welding, wherein the surfacing welding hardness of a sealing surface reaches 45-50 HRC, and the method can be used in a working environment with PN less than or equal to 80Mpa and t less than or equal to 670 ℃. Practice proves that the cobalt-based hard alloy is adopted as the sealing surface, so that the wear resistance, the erosion resistance and the long service life are realized. The sealing surfaces of the valve seat and the upper valve seat can also be prepared in the same way as the sealing surface of the valve core.

The included angle (cone angle) of the sealing surface of the valve seat is larger than or smaller than the included angle (cone angle) of the sealing surface of the valve core. In this embodiment, the included angle of the sealing surface of the valve seat is 35 ° 30 ', and the included angle of the sealing surface of the valve element is 36 ° 30'. The valve core and the valve seat have an angle difference of 1 degree, and the valve core and the valve seat also have a hardness difference of 6-10 HRC. The valve core and the valve seat form a sealing line with a certain width after elastic deformation, and under the same sealing force, larger sealing specific pressure is generated, and the sealing is easier.

The valve body further comprises a medium inlet branch pipe 7 and a medium outlet branch pipe 10, a medium inlet channel 8 and a medium outlet channel 11 are respectively arranged in the medium inlet branch pipe and the medium outlet branch pipe, the two medium channels are communicated with the valve rod hole, the position where the medium inlet channel is communicated with the valve rod hole is higher than the position where the medium outlet channel is communicated with the valve rod hole, the cross section centers of the outlet of the medium outlet channel and the inlet of the medium inlet channel are located in the same horizontal plane, and the connecting line of the two is a horizontal line.

The central axes of the medium inlet channel and the medium outlet channel are coplanar with the central axis of the valve rod hole (reducing circular hole), the central axes of the two medium channels are parallel and obliquely arranged, and an included angle of 20 degrees is formed between the central axes and the horizontal plane, so that the flow resistance of the valve is reduced to the maximum extent.

The axial span (or height) of the valve core or the distance from the lower edge of the lower flange of the valve core (the lowest point of the lower flange) to the top surface of the valve core is preferably not more than the distance from the bottom surface of the inner flange of the throttle sleeve to the upper edge of the throttle hole (the highest point of the throttle hole). When the valve is opened, the part of the valve core from the lower flange to the upper part is completely higher than the position where the medium inlet channel is communicated with the valve rod hole, the valve core does not influence the medium circulation, and the sealing effect (upper sealing effect) at the position of the valve filler under the full-open state of the valve can be ensured.

The valve seat can be subjected to EDCoCrA-03 surfacing welding, and can be machined for multiple times, so that the valve seat is convenient to repair on line. The surfaces of the valve rod and the valve core can be subjected to hardening treatment, the valve rod and the valve core can be made of materials which are different according to different media and parameters, the materials can be 20Cr13, F316, F304, 25Cr2MoVA, 25Cr2Mo1VA, 22Cr12NiWMoV, X35CrMo17, NO7750, NO7718 and the like, and the valve core can also be made of 12 Setaili as a whole.

The sealing part of the valve rod, which is contacted with the filler, can be subjected to surface treatment such as extrusion polishing treatment, nitriding treatment, carburizing treatment, carbonitriding treatment and the like, so that the wear resistance, scratch resistance and corrosion resistance of the valve rod are effectively enhanced.

The working principle of the utility model is as follows:

when the valve is closed, the valve rod moves downwards under the pushing of the pneumatic actuating mechanism and the acting force of the medium and the friction force of the filler is overcome; when the sealing surfaces are in contact, the valve is closed. The force exerted by the pneumatic actuator (drive) is sufficient to ensure that a sufficient sealing force is always maintained on the sealing surfaces. Since the valve is designed to enter the valve body from above the valve seat, i.e. high in and low out, the maximum force occurs at the moment the valve is opened.

The sealing surface of the base hard alloy is ground, the surface roughness can reach Ra0.1 mu m, the sealing surface is always kept tight under the action of sealing force without internal leakage, and then the filling part only bears the action of medium pressure behind the valve, and the filling is kept sealed by the pressure of the filling gland.

When the valve is opened, under the action of an air source, the pneumatic actuating mechanism generates upward thrust, the direction of the thrust is opposite to that of the medium action, the valve is opened after the medium action and the filler friction are overcome, and the valve is completely opened after the upper sealing R surface of the valve rod is in sealing contact with the anti-impact throttling sleeve.

When the valve is closed, the pneumatic actuating mechanism generates a downward thrust under the action of an air source, and the direction of the downward thrust is consistent with the direction of the action force of the medium; under these two forces, the friction of the packing is overcome, eventually generating sufficient sealing force on the sealing surfaces. After the sealing surface of the valve core is contacted with the valve seat, the sealing surface has an angle difference of 1 degree; the metal on the sealing surface is elastically deformed to form a narrow sealing line, and the narrow sealing line enhances the reliability of valve sealing.

The valve with the novel structure has wide application range, the nominal pressure is increased from PN160bar to PN760bar (equivalent to CL900 to CL 4500) in the prior art, the use temperature is increased from below 540 ℃ to above 615 ℃, and the manufacturing and inspection standards of products are changed from domestic standards to reference and implement foreign advanced manufacturing and acceptance standards.

In the present specification, the terms "upper" and "lower" are used with respect to fig. 1 only for convenience of expressing the relative positional relationship of the respective components, and do not limit the specific structure of the present invention.

The technical means disclosed by the utility model can be combined arbitrarily to form a plurality of different technical schemes except for special description and the further limitation that one technical means is another technical means.

Claims (10)

1. Hydrophobic pneumatic stop valve in power station, including the valve body, its characterized in that be equipped with vertical valve pocket in the valve body, be equipped with disk seat and upper seal disk seat in the valve pocket, disk seat and upper seal disk seat will the valve pocket separates for epicoele, lumen and cavity of resorption, the disk seat is located between lumen and the cavity of resorption, the upper seal disk seat is located between epicoele and the lumen, the sealing surface of disk seat is up, the sealing face of upper seal disk seat is down, constitutes valve seal and upper seal with the lower sealing face and the upper sealing face of case respectively, the case is located the lumen, with lumen sliding fit, the valve rod passes the epicoele, its lower extreme is connected the case, and the upper end is located outside the valve body for connect drive arrangement, the medium passageway intercommunication of advancing of valve the lumen, play medium passageway intercommunication the cavity of resorption.

2. The power station drainage pneumatic stop valve comprises a valve body and is characterized in that the valve body is provided with a vertical reducing round hole, the reducing round hole is a blind hole with an open upper end, the aperture of the upper section of the reducing round hole is larger than that of the lower section of the reducing round hole, a valve seat is arranged at a reducing part between the upper section and the lower section of the reducing round hole, a cylindrical throttling sleeve is arranged in the reducing round hole, the throttling sleeve is positioned at the lower part of the upper section of the reducing round hole, the bottom surface of the throttling sleeve is abutted against the reducing end surface of the reducing round hole, the outer side surface of the throttling sleeve is matched with the inner wall of the upper section of the reducing round hole, the inner diameter of the throttling sleeve is larger than that of the lower section of the reducing round hole, an expansion section is further arranged in the reducing round hole, the expansion section is positioned between the upper end and the lower end of the throttling sleeve in the axial direction, the aperture of the expansion section is larger than the outer diameter of the throttling sleeve, and an annular gap allowing a medium to flow is reserved between the inner wall of the expansion section and the throttling sleeve, the side wall of the throttling sleeve is provided with a radial throttling hole communicated with the annular gap, the inner end of a medium inlet channel of the valve body is communicated with the annular gap, the inner end of a medium outlet channel of the valve body is communicated with the lower part of the lower section of the reducing circular hole, the throttling sleeve is internally provided with a valve core, the valve core is in a shape of a rotary body, is provided with a top surface and a bottom surface and is in a waist shape, the upper part and the lower part of the side surface of the valve core are respectively provided with an upper flange protruding outwards in the radial direction and a lower flange protruding outwards in the radial direction, the outer side surface of the upper flange and the outer side surface of the lower flange are cylindrical surfaces, the diameters of the upper flange and the lower flange are equal, the upper flange and the lower flange are in sliding fit with the inner wall of the throttling sleeve, a top opening of the throttling sleeve is provided with an inner flange protruding inwards in the radial direction, the top of the valve seat and the bottom of the valve core are respectively provided with mutually matched sealing surfaces, the top of the reducing round hole is provided with a packing gland, the valve rod penetrates through the top opening of the throttling sleeve and the middle hole of the packing gland, the lower end of the valve rod is connected with the valve core, the upper end of the valve rod is positioned outside the valve body, a packing chamber for sealing the valve rod is positioned between the valve rod and the inner wall of the reducing round hole in the radial direction and positioned between the throttling sleeve and the packing gland in the axial direction, and packing for sealing is filled in the packing chamber or a sealing element is arranged in the packing chamber.

3. The station drainage pneumatic stop valve according to claim 2, characterized in that the spool is provided with a blind valve stem hole with an open upper end, the lower end of the valve stem extends into the blind valve stem hole, and an annular pin for connecting the outer side surface of the valve stem in the blind valve stem hole and the inner wall of the blind hole is arranged between the outer side surface of the valve stem and the inner wall of the blind hole.

4. The station trap air operated shut off valve of claim 2 wherein the lower end of said valve stem is a convex surface of revolution.

5. The station drain pneumatic stop valve according to claim 2, characterized in that the packing gland is shaped as a revolution body, the upper part of the outer side surface of the packing gland is provided with an annular flange protruding outwards in the radial direction, the top surface of the annular flange is umbrella-shaped, a pressure plate is arranged above the packing gland, the bottom of the pressure plate is provided with a conical concave surface corresponding to the top surface of the annular flange and presses on the top surface of the annular flange, two mounting lugs symmetrically extend outwards from two sides of the pressure plate, and the mounting lugs are provided with rectangular notches opened in the centers of the outer ends.

6. A power station hydrophobic pneumatic stop valve as claimed in claim 5, characterized in that the valve cover is fixedly mounted on the top opening of the valve body, two bolt connecting lugs are symmetrically arranged on two sides of the valve cover, the pressure plate fastening bolt is a loose joint bolt, and the loose joint bolt is hinged on the bolt connecting lug on the corresponding side through a pin shaft.

7. A hydrophobic pneumatic stop valve for electric power stations according to claim 2, characterised in that the gland is of a two-part construction, consisting of two gland halves which are mirror-symmetrical with respect to any longitudinal section, in a closed configuration.

8. A station trap pneumatic stop valve as in claim 2, characterized in that the sealing surface of the top of the valve seat and the sealing surface of the bottom of the spool are conical.

9. A plant trap pneumatic stop valve as claimed in claim 8, characterised in that the inner edge of the sealing surface of the bottom of the spool is located radially inside the inner edge of the sealing surface of the top of the valve seat and the outer edge is located radially outside the outer edge of the sealing surface of the top of the valve seat, the sealing surface of the bottom of the spool having a greater cone angle than the sealing surface of the top of the valve seat.

10. The station drain pneumatic stop valve according to claim 2, characterized in that the sealing surface at the bottom of the inner flange is a conical surface with a small top and a large bottom, the inner edge of the inner flange is connected with the horizontal bottom surface of the inner flange, the outer edge of the inner flange is connected with the cylindrical inner side surface of the throttling sleeve, and the sealing surface at the top of the valve core is a convex rotating curved surface.

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