CN108343775B - Power station main steam system top steam discharge electromagnetic relief valve - Google Patents

Abstract

The invention discloses a kind of power station main steam system top steam discharge electromagnetic relief valve, the valve is that major-minor valve is split type, top is in line or top bilateral steam discharge；Main valve clack is made of thermal valve valve and outer flap, and thermal compensation, elastic compensating and Anti-clamping structure are provided on main valve clack；Guide sleeve is fixed using assembling structure, by pressure rack；Condensed water container structure is provided on the upside of main and auxiliary valve sealing surface；Auxiliary valve sealing surface is using spherical surface-cone structure and has thermal compensation slot；Combined sealing structure is used at main and auxiliary valve lumen；Auxiliary valve upper end is provided with vapor-proof escape structure；Region of interest is provided with the partial structurtes that can improve flow field characteristic in valve.Major advantage: the problem of no condensed water and oxidation corrosion product influence valve seal, main and auxiliary valve sealing surface compensation ability is strong, high sealing reliability, main valve clack elastic gap is not easy blocking, main and auxiliary valve lumen is without external leakage, guide sleeve is fixed reliable, conveniently, and when discharge is smaller without steam evolution, vibration and noise.

Description

Power station main steam system top steam discharge electromagnetic relief valve

The application is that application No. is 2014107559134, invention and created names are as follows: power station main steam system uses top row Vapour electromagnetic relief valve, the applying date are as follows: the divisional application of the application for a patent for invention on December 08th, 2014.

Technical field

The present invention relates to a kind of valve mechanisms, and in particular to top row vapour electromagnetism used in a kind of power station main steam system is let out The product structure of pressure valve.

Background technique

Electromagnetic relief valve is the important safety relief valve of one kind of power station main steam (crossing hot vapour) system, is one kind with electricity The driving devices such as magnet driving guide's flap releases steam and the pilot-operated type valve that acts main valve clack.Electromagnetic relief valve is mounted on Before main steam spring safety valve, be main steam safety valve equalizing valve and protection valve, set by popping pressure value The slightly below popping pressure of main steam safety valve is pressed when superpressure occurs in main steam but without the jump of opening for reaching main steam safety valve Electromagnetic relief valve quickly opens discharge steam when force value, and the pressure of system is down to normal value, as avoids main steam safe as possible Valve events keep unit to maintain Performance And Reliability, the use for extending main steam safety valve and the maintenance cycle of safety valve Enough safety assurance abilities and the balance and stable operation for guaranteeing unit, and can be that may be needed together according to unit operation conditions Shi Jinhang's opens turbine by pass fastly, reduces combustion intensity, the control of a series of complex such as steam water-level is maintained to win valuable buffering Time is the important mating valve and critical valves of fired power generating unit.

The actual needs of pressure control when electromagnetic relief valve is according to unit starting and operation, can automatically and manually open Valve can also pass through lock operation state；The control system of electromagnetic relief valve selects high-precision pressure switch (pressure sensor), Controllable blowdown of a safety valve reaches 2%.It is with U.S.'s De Laisai-Kang Suo Reed that solenoid blowout valve products application is more at present (Dresser-Consolidated) and the product of the enterprises such as Crosby (Crosby) is that representative uses main valve clack sealing surface Upward, the product of top row vapour, auxiliary valve fission side assembling structure (see Fig. 1 and Fig. 2).It is main for the electromagnetic relief valve of this structural shape Advantage is that the structure of runner is relatively simple, and valve body of main valve is convenient for being processed using forging, thus be conducive to make valve keep compared with High security reliability.

Due to product structure design, electromagnetic relief valve is had become in the matched all kinds of valves of fired power generating unit institute at present Always exist one of the critical valves of more serious problem.Existing main valve clack upward, top row vapour, auxiliary valve fission side dress electromagnetism let out Pressure valve product existing in use disadvantage and problem have: 1, due to discharge of steam, exhaust pipe and outlet connection The inner cavity of flange can oxidation corrosion quickly, can especially occur quickly in exhaust passage when valve has certain leakage more serious Corrosion phenomena because valve be top steam exhaust structure, the corrosion products such as oxide skin can fall or with condensed water flowing and gather Near main valve clack sealing surface, to can be affected to the sealing of valve；2, top steam exhaust structure can make main valve clack upper end surface There is condensed water to splash drop or accumulate condensed water, and the outside of main valve clack sealing surface is located at valve cavity, directly contacts with high-temperature steam, Thus on the inside of the inside part of main valve clack sealing surface or entire sealing surface with the outside of main valve clack sealing surface can therefore and generate compared with The big temperature difference and be deformed sealing surface position even and crack, the use of valve is caused to be affected；3, the guide of auxiliary valve is close Similarly there are problems that at cover it is above-mentioned this, can constantly have after steam discharge under condensed water seep to sealing surface different parts, make Sealing surface position generates inhomogeneous deformation because of continuous partial cooling, causes electromagnetic relief valve product generally existing in use Auxiliary valve opens rear sealing surface for several times and starts occur leaking the phenomenon that this allows power station user to have a headache very much, and auxiliary valve occurs after leaking again The back pressure deficiency that will lead to main valve clack then causes main valve clack sealing surface to leak；4, main valve clack and guide's valve clack sealing surface Design is mostly the conventional integrated valve valve structure without thermal compensation ability.The main steam temperature of large capacity fired power generating unit is usually 540 ~610 DEG C, for valve in working condition, the outside of valve clack sealing surface is main steam, and temperature is higher, and the inside of valve clack sealing surface Because communicated with atmosphere temperature can be declined thus temperature be lower than valve clack sealing surface outside, internal-external temperature difference is larger to will lead to deformation And influence valve seal；5, main valve clack and pilot valve flap seal face position using no thermal compensation ability conventional monoblock type flap knot Structure, when sealing pair somewhere leaks, the medium leaked out is because sharply swelling heat absorption can make near sealing face leakage point volume Temperature decline, unbalanced temperature change will lead to sealing surface again and generates inhomogeneous deformation to aggravate to leak；6, discharge is steamed When vapour or when auxiliary valve has leakage, auxiliary valve upper end has steam evolution, in addition to that can affect production environment, and influences to drive Outside the functional reliability of device, prior influence is that the high-temperature steam of evolution can make the machinery of the spring on the upside of auxiliary valve valve deck Performance is affected, and elasticity reduces, to influence whether the sealing of auxiliary valve and the reliability of auxiliary valve closing motion, meeting when serious Make to occur leaking greatly or closing valve rod can not at sealing surface；7, the sealing reliability at valve body and valve seat mounting surface is poor, external leakage Problem is more serious.The valve body and valve seat location of Crosby (Crosby) company electromagnetic relief valve product and the valve body of auxiliary valve It is sealed with valve deck position using V-type metal o-ring (as shown in figure 12, piece number 32 is the V-type metal o-ring), And the product of De Laisai-Kang Suo Reed (Dresser-Consolidated) company then uses the sealing of c-type metal o-ring (such as Shown in Figure 13, piece number 33 is c-type metal o-ring), then use soft graphite wound gasket to seal at the valve body valve deck of its auxiliary valve.V Type or c-type metal o-ring generate seal pressure by the elasticity tension and pressure self-sealing effect of itself, but due to following The influence of two factors, sealing reliability can not often be met the requirements: first is that because the valve seat of said two products is adopted Be mounted on valve body with the mode of threaded engagement (see Fig. 1, Fig. 2), metal o-ring pre-pressing and generate initial sealing than pressure be It is realized by screwing valve seat, since metal o-ring is made of stainless steel material, anti-scuffing function is poor, and valve seat Or the anti-scuffing function of the bulk material of valve body is not also strong, thus during screwing seat compression metal o-ring, It is easy to produce scratch phenomenon at sealing ring and the contact surface of valve seat or valve body and influences to seal；Second is that because V-type or c-type metal are close The contact area very little of seal and valve body and valve seat sealing surface, essentially line contact condition, when valve runs on worst hot case When (main steam temperature of large capacity fired power generating unit be 540~610 DEG C), valve body, the intensity of seat material and hardness can decline, mould Property increase, on valve body, valve seat with metal o-ring in line contact condition surface can because be pressurized generate plastic deformation due to it is recessed, make Specific contact pressure decline, causes sealing reliability to reduce.Electromagnetic relief valve product sealing positions such as valve body, valve seat in installing and using External leakage occur is a more typical problem；When needing replacing sealing element, the price of an import metal o-ring can be high Up to four to five Wan Yuan, and Lead Time is up to dozens of days, greatly increases the product repairing cost of power plant, maintenance cycle lengthens, system The difficulty and uncertain increase for determining maintenance project, bring larger impact to the operating maintenance of power station unit.8, existing product Fixed form and structure for the guide sleeve of main valve clack guide-localization in valve be usually by guide sleeve to be interference fitted Mode is partially or completely pressed into and fixes on the support frame or on valve body (Fig. 1, Fig. 2), and disadvantage present in this mode has: one It is poor reliability, the judder and collision, the disturbance of flow at high speed medium and the master that may occur when being easy because of steam discharge The bite of flap and guide sleeve and make guide sleeve deviate from or part deviate from；Second is that assembly and maintenance inconvenience, processing request are high.9, The structure of guide's sealing position: it since electromagnetic relief valve product is for the needs for the response speed for executing switching motion, is used Driving device (generally use solenoid actuated) nominal force it is smaller, along with existing electromagnetic relief valve product is basic On be the drive mechanism that this is not appropriate for using the lesser lever construction of amplification factor to power to transmit the drive of driving device Power, thus so that valve rod is can be obtained thrust and be restricted；It is influenced by this factor, guide's sealing surface of existing product Diameter be all designed smaller；Since guide's sealing surface is mainly to guarantee to seal by top power on the medium after closing, thus Smaller its of sealing surface diameter can be obtained that medium active force is also smaller, sealability is also poorer.The valve rod of existing product and Guide's flap generally uses the design of split, due to smaller (such as existing product valve rod of the size of valve rod, flap and snap ring Diameter at the axle journal of lower part is only less than 7mm), thus valve rod and guide's flap use split and carry out group with assembling structure The mode (Fig. 2) of dress, reliability can be poor, and along with guide's flap is whole hard alloy material, brittleness is very big, is bearing The problems such as being easy to appear fracture at connection structure when returning the moment impact of seat, leads to valve cisco unity malfunction；Crosby (Crosby) design of the product of company valve rod and guide's flap integral type despite the use of, but guide's sealing surface use it is flat The structure (seal f ace width b=1mm) of face sealing, although facilitating the grinding of sealing surface, it is sealed compared with conical surface seal Ability receives certain limitation；10, it is fixed to be used for guide's flap for the electromagnetic relief valve of valve rod and guide's flap split structure Because being restricted by structure at the guide sleeve of position guiding, for pressure release and after opening, through-flow perforated area is less than normal, limits guide Discharge of steam speed when flap is opened is to make Valve opening velocity be affected；11, there are many places to easily lead to for the runner of valve Discharge of steam generates the position of more serious vortex when flowing, the medium on the downside of main valve inner support frame is from entrance side upwards toward support At shunting in frame on the outside of hub, on the upside of main valve clack, near support frame dowel；For swiftly flowing gas medium, stream Once there are more serious vortex in road, vibration and noise caused by media flow can be made to significantly increase, while strong vibration The dynamic functional reliability that can make valve again and service life decline；12, as previously mentioned, existing top row vapour electromagnetic relief valve product Main valve clack is not considered as compensation design, and sealing reliability of the sealing surface in worst hot case can be made to be affected, it is opposite and Speech, Japanese enterprises two sides steam discharge produced, the auxiliary valve integral structure of main valve electromagnetic relief valve product then in main valve flap seal The structure design that joined thermal compensation in the structure in face, can be such that the elevated-temperature seal reliability of valve sealing face is improved.But The main valve valve structure of the electromagnetic relief valve with thermal compensation function in structure design aspect there is also some shortcomings, So that the sealing structure of main valve clack can not give full play to its due effect: be first, at main valve clack sealing surface although set up Thermal compensation and elastic compensating structure, but the tapering of thermal valve valve only at cone end elasticity tongue it is relatively thin, have the elasticity being relatively good Crooked deformability, and tapering becomes larger rapidly with cone angle is up then rigid, thus the reasonability of elastic compensating structure is not good enough, and close Cover position is handled by quench hardening, if relying primarily on cone end and providing elastic bending deflection compensation, is being born back There are some problems for its reliability when seat impact；Secondly, main valve clack sealing surface elastic tongue on the upside of cavity at it is not set outward Through-hole, be closed and will be without high-temperature steam at the cavity when reaching preferable sealing state once flexible deformation gap location because being pressurized It is able to enter, this loses the thermal compensation function that will lead at main valve clack sealing surface substantially；In addition, main valve clack seals surface elastic tongue Locate setting flexible deformation gap, the gap main valve clack open discharge steam when be in open configuration, the opening in gap meet to Medium inflow direction, the small impurity particle (such as small oxide skin, solder joint welding slag and other impurity) being present in discharge medium It is easy to be embedded in flexible deformation gap the sealing condition for making main valve clack sealing surface along the flow direction of media discharge It is affected.

In order to solve the problems, such as that main valve clack sealing surface position bring due to no thermal compensation ability deforms and leaks this, De Lai Sai-Kang Suo Reed (Dresser-Consolidated) company is outside the main valve clack sealing surface of its electromagnetic relief valve product (Fig. 2) Side increases thermal compensation slot (see Fig. 3), thermal compensation slot increase sealing surface nearby and high-temperature steam contact area and make main valve The Distance Shortened at sealing surface position and high-temperature steam is leaned in valve upper end, thus can have more heat transfers to lean on to main valve clack upper end The position of sealing surface reduces the temperature difference in outside in sealing surface.Main valve clack helps to control by increasing above-mentioned thermal compensation slot The deformation that sealing surface position is generated by the temperature difference, but thus groove depth will receive centainly the intensity due to needing to guarantee sealing surface position Limitation, this is but also the thermal compensation ability of the structure is difficult to really meet the requirements.

Summary of the invention

In order to overcome many shortcomings above-mentioned present in existing structure and technology, the invention proposes one kind not Entering main valve clack sealing surface there are oxidation corrosion product, nearby influence valve seal and condensed water cause main valve and auxiliary valve to seal The problem of face leaks can prevent main valve and lumen external leakage phenomenon, main valve and the auxiliary valve sealing surface of auxiliary valve completely and have More sufficient thermal compensation ability and better seal reliability, main valve clack sealing surface position have stronger elastic compensating ability, Flexible deformation gap at elastic tongue is not easy to be blocked, guide sleeve can be fixed reliably, vibration when discharging steam and Noise is smaller, can effectively prevent steam from auxiliary valve valve deck in valve steam discharge or when certain leakage occurs in the interior sealing of auxiliary valve Upper end escapes outward, and valve is enable preferably to meet the super (super-) critical of the especially modern large capacity of fired power generating unit, high parameter The power station main steam system of the needs of fired power generating unit safe and reliable operation top steam discharge electromagnetic relief valve structure.

To achieve the goals above, the invention adopts the following technical scheme:

A kind of power station main steam system top steam discharge electromagnetic relief valve, the electromagnetic relief valve main valve and auxiliary valve are point Body formula structure, auxiliary valve are installed on the side of main valve, and the exhaust steam end that valve is used to discharge steam is located at the top-of main valve in main valve valve The upper end of body is provided with steam exhaust structure body, and the downside of steam exhaust structure body is connected simultaneously with flange and bolt connection with valve body upper end And compress valve seat；The structural shape of valve body is revolution figure, is welded by upper and lower two parts, is provided in the middle part of valve body For supporting and fixing the support frame of the parts such as main valve clack, embedding upper and lower two parts for being sandwiched in valve body in outer ring of the annular of support frame Between, the circular passage between the interior hub in the middle section-of support frame and the outer ring of support frame passes through from bottom to top for medium, Between interior hub and outer ring and multiple dowels are equipped with, interior hub is made to be supported and be fixed in the intracorporal position of valve.Valve is by driving Dynamic device drives the valve rod of auxiliary valve to act, open guide's sealing structure and open the main valve clack in main valve.Key of the invention Technical solution are as follows: main valve clack uses flap modular construction, and flap component is made of thermal valve valve and outer flap, thermal valve valve and outer flap Be revolution figure part, the two be concentric arrangement, thermal valve valve inside and outer flap outside, the two simultaneously with threaded engagement connection is One；Thermal valve valve upper surface outer circumferential side is the valve clack sealing surface of circular ring shape, and thermal valve valve is provided with cone in the back side of valve clack sealing surface Face, while the adjacent position on outer flap on the outside of the above-mentioned conical surface is also provided with the conical surface of identical taper, in flap group When free state when part is in unassembled, there are small gaps between the above-mentioned two adjacent conical surface, and are in flap component Then two conical surfaces are in contact when work condition state is pressurized；Elastic groove, the elastic groove packet are additionally provided at the conical surface of the thermal valve valve Containing upper and lower step plane and cylindrical surface, with round-corner transition between cylindrical surface and upper and lower step plane.Outer flap is close to valve The vertical height of upper surface at the outer diameter of flap seal face, higher than the vertical height of valve clack sealing surface.Positioned at flap component outside, The guide sleeve of tubular for flap component guide-localization, lower end are installed positioning with cylindrical positioning surface on the support frame, are led It is equipped with step surface to the outer circle of set, the boss lower plane on the outside of valve seat is additionally provided with pressure rack down, and pressure rack is to turn round figure simultaneously The through-flow window of window-of multiple perforations is machined in outer circle, for medium by flowing into inside outside, the upper and lower end face of pressure rack is distinguished On step on boss lower plane on the outside of valve seat and guide sleeve outer circle between plane, after the position of pressure rack is fixed, Guide sleeve is capable of fixing also in installation site simultaneously by the retaining position-limiting action of pressure rack.

Steam exhaust structure body positioned at valve body of main valve upper end can be connected using the connecting flange with upper and lower flange end, upper end Acting flange when installing with the gland steam exhauster of side disposed thereon for connecting.

In order to which expected purpose is better achieved, the present invention also adds following further technical solutions simultaneously:

Steam exhaust structure body positioned at valve body of main valve upper end can also further use new structural shape-triplet type knot Structure, in-between vertical channel shunt to form horizontal channel toward arranged on left and right sides direction upwards, and left and right horizontal channel is in both ends end It being symmetrically arranged with connecting flange, being connected when for installing with the steam discharge elbow of two sides；The material of steam exhaust structure body is stainless steel Material, left and right horizontal channel have the taper being gradually reduced near aperture or aperture to interior diameter at both ends.

Cavity-main valve condensation water chamber of annular is provided between steam exhaust structure body lower end and valve seat, the main valve is solidifying Room is born water by the platform of plane on boss on the outside of valve seat and the valve seat outer circle on the upside of it and steam exhaust structure body intermediate vertical channel lower end Rank hole is surrounded；Steam exhaust structure body intermediate vertical channel lower end is located at the aperture on the upside of valve seat at adjacent regions and is greater than among valve seat Aperture at the aperture of access opening upper end is stayed between the lumen orifice of steam exhaust structure body intermediate vertical channel lower end at the outer circle of valve seat upper end There is the gap of annular that main valve condensation water chamber is made to be connected with the inner cavity of steam exhaust structure body；It is compressed in valve seat by steam exhaust structure body convex At plane and gasket is provided on platform.

The lower end of auxiliary valve valve deck is provided with guide's valve seat, guide's valve seat is connected and sealed with auxiliary valve valve deck, on auxiliary valve The guide's sealing surface for executing switching motion is set up directly on the lower part of valve rod, and the valve rod with stem lower portion is provided on guide's valve seat The sealing surface of sealing surface pairing；Valve stem seal face is spherical surface, and the sealing surface on guide's valve seat is then the downward conical surface in direction of dehiscing, It is coincide both when closing with tangent state；Back side in valve stem seal face is provided with groove-thermal compensation slot of annular；It is close from valve rod The outer diameter of cover is toward having one section of cylindrical section, and in the cylindrical section, then outer diameter increase is constituted and led for the bearing of valve rod lower end still further below To another section of cylindrical surface, the sealing surface of first guide valve seat is toward being arranged with and the above-mentioned circle for valve rod lower end bearing guiding The cylindrical hole of cylinder cooperation；From between the cylindrical section of the upside and valve stem seal face outer diameter of the above-mentioned cylindrical hole of guide's valve seat down Toroidal cavity it is outside, be drilled with uniformly distributed several through flow holes, be also drilled in valve rod lower end surface toward above-mentioned toroidal cavity uniformly distributed Several through flow holes.

The loudspeaker that diameter increases down is equipped in the lower end of the intermediate exhaust passage for the auxiliary valve valve deck being located on the upside of pilot valve seat The conical surface of the degree of lip-rounding-water guide conical surface, first guide valve seat positioned at the above-mentioned water guide conical surface downside and be equipped with opening up annular The auxiliary valve of groove-condense water chamber, between the steam through flow hole among auxiliary valve condensation water chamber and guide's valve seat, have from auxiliary valve condensed water Water-resisting wall that indoor up extends, circular ring shape is separated by, and the upper end outer diameter of water-resisting wall is less than the internal diameter of water guide conical surface lower end, because And have certain through-flow gap between the upper end of water-resisting wall and the lower end of the water guide conical surface, from the intermediate exhaust passage of auxiliary valve valve deck The condensed water that flows down of hole wall can be flowed into downwards in auxiliary valve condensed water room along the surface of the water guide conical surface.

Sealing at valve body and valve seat mounting surface uses Multiple Combination sealing structure, the Multiple Combination sealing structure packet Metal o-ring and spirotallic gasket containing circular ring shape；The section of the metal o-ring is structure symmetrical above and below, metal sealing Circle is pressure seal section by inner radius, and the pressure seal section includes the circle by cutting out outward in the middle part of metal o-ring internal diameter The pressure-bearing cavity portion of annular, metal o-ring upper and lower surface is between the annular surface and pressure-bearing cavity upper and lower surface of internal side diameter Elastic packing tongue that entity is constituted, metal o-ring upper and lower surface are located at the ring on the outside of elastic packing tongue and being inwardly recessed The thinned recessed portion of shape；Upper and lower surface in the side of the close outer diameter of metal o-ring is provided with the rank for the annular being inwardly recessed Terraced plane is simultaneously placed with spirotallic gasket in the recessed ladder plane；It is located at spirotallic gasket and by internal diameter in metal o-ring Upper and lower surface between the pressure seal section of side is additionally provided with tooth form seal section, and the tooth form seal section is in metal sealing The gold that the wide narrow concentric circles anchor ring that the upper and lower surface of circle leaves after carving the groove equidistantly arranged except several is formed Belong to sealing tooth；The upper-lower seal surface that the elastic packing tongue of pressure seal section is contacted with valve body, valve seat is in not before assembly When pressured state, the sealing surfaces are slightly above the surface for the metal sealing tooth being thinned on the outside of recessed portion.

Sealing between auxiliary valve body and auxiliary valve valve deck on the upside of it uses compound gasket structure, the compound gasket knot Structure is made of tooth profile metal pad+wound gasket, two kinds of gasket concentric arrangements, one inside another on the outside, be placed on auxiliary At the seam allowance plane of valve body upper end.

The upper end of auxiliary valve valve deck is provided with gland, gland is with the inner hole of the outer circle of its lower end and auxiliary valve valve deck upper end With positioning, fixation is installed on auxiliary valve valve deck with screw；Upper section inner hole and valve rod the outer circle cooperation of gland constitute valve rod upper end Support guide surface；The aperture of the lower section inner hole of gland is greater than the outer diameter of a circle of valve rod, is provided in the lower section inner hole of gland The vapor-proof escape structure for preventing steam from escaping from auxiliary valve valve deck upper end when valve stem seal face is opened, the vapor-proof escape knot Structure escapes ring by internal resistance and extrernal resistance ease ring is staggered and constitutes, and when internal diameter processing of internal resistance ease ring is slightly smaller than the outer diameter, outer of valve rod Slightly larger than the internal diameter of the lower section inner hole of gland, the side of two kinds of resistance ease rings are splitted with wire cutting when the outer diameter processing of resistance ease ring And certain spring expanding or contraction can be generated.

At the position at the rear surface of the interior hub of support frame, the medium inlet end of face valve body, be provided with taper, by with The plane tangent of interior hub circular arc revolution be formed by, downwardly projecting lower spreader；At the middle part of the upper surface of thermal valve valve Be provided with taper, by with the upper transverse plane of thermal valve valve it is tangent circular arc revolution be formed by, the shunting of cone cell protruding upward Cone；In addition, the cross sectional shape of hub and the dowel of outer ring is also configured as the oval with low flow resistance characteristic in connecting on support frame Shape.

Electromagnetic relief valve of the present invention, driving device include by electromagnet provide active force driving device, and The driving device of active force is provided by solenoid valve control pneumatic mechanism.

The beneficial effects of the present invention are: 1, using structure described in technical solution of the present invention after, there would not be oxidation The problem of corrosion product and condensed water enter main valve clack sealing surface nearby and influence valve seal；2, the sealing surface of main valve and auxiliary valve Position has more sufficient thermal compensation ability, along with the design of reasonable sealing structure has valve more in work condition state Good sealing reliability；3, the resilient tongue position of main valve clack sealing surface has stronger elastic compensating ability, to be more advantageous to Guarantee that valve can be chronically at zero leakage condition；4, protection of the flexible deformation gap at elastic tongue in set protection structure Under be not easy to be blocked, thus be more advantageous to guarantee valve sealing；5, the condensed water being arranged on the upside of auxiliary valve sealing surface stores knot Structure solves the problems, such as that condensed water present in existing product influences auxiliary valve sealing；6, the lumen sealability energy of main valve and auxiliary valve Access great improvement；Even if external leakage phenomenon occurs in valve lumen under special circumstances, maintenance cost can also drop significantly It is low；7, guide sleeve can be fixed reliably；8, the vapor-proof escape structure of auxiliary valve valve deck upper end setting can effectively protect life Environment is produced, guarantees driving device reliably working, guarantees that the working performance and reliability of spring and auxiliary valve are unaffected；9, steam is arranged When putting, flow field is more reasonable, and vibration and noise is smaller.

Detailed description of the invention

Fig. 1 is the prior art-Crosby company, U.S. top row vapour electromagnetic relief valve schematic diagram.

Fig. 2 is the prior art-De Laisai-Kang Suo Reed company, U.S. top row vapour electromagnetic relief valve schematic diagram.

Fig. 3 is that the main valve clack sealing surface outside of electromagnetic relief valve shown in Fig. 2 increases the schematic diagram of thermal compensation slot.

Fig. 4 is the schematic diagram of product structure of the embodiment of the present invention one.

Fig. 5 is the schematic diagram of product structure of the embodiment of the present invention two.

Fig. 6 is the left-hand cross-sectional view of the primary valve part of embodiment two shown in fig. 5.

Fig. 7 is the structural schematic diagram of the flap component of the embodiment of the present invention.

Fig. 8 is the partial enlargement diagram at flap component sealing surface position.

Fig. 9 is the structural schematic diagram of the pressure rack of the embodiment of the present invention.

Figure 10 is the schematic diagram of the steam exhaust structure body of embodiment two and the condensed water container structure of valve seat location.

Figure 11 is the condensed water container structure of the auxiliary valve bonnet lower of the embodiment of the present invention and the signal of guide's sealing structure Figure.

Figure 12 is the valve body of main valve of Crosby Products and the signal that valve seat location uses V-type metal o-ring to seal Figure.

Figure 13 is that the valve body of main valve of De Laisai-Kang Suo Reed product and valve seat location are sealed using c-type metal o-ring Schematic diagram.

Figure 14 be the valve body of main valve of the embodiment of the present invention, valve seat location Multiple Combination sealing structure schematic diagram.

Figure 15 be the auxiliary valve body of the embodiment of the present invention, valve deck position compound gasket structure schematic diagram.

Figure 16 is the structural schematic diagram of the auxiliary valve valve deck upper end of the embodiment of the present invention.

Figure 17 is the structural schematic diagram of the support frame of the embodiment of the present invention.

In figure, 1, valve body；2, support frame；2-1, outer ring；2-2, interior hub；2-3, dowel；2-4, lower spreader；3, main valve Spring；4, guide sleeve；5, flap component；5-1, thermal valve valve；5-2, valve clack sealing surface；5-3, elastic groove；5-4, outer flap；5-5, Aperture；5-6, straight pin；5-7, damping slot；5-8, into pressure passageway；5-9, spreader；5-10, anti-sticking protective edge；6, pressure rack；6-1, Through-flow window；7, Multiple Combination sealing structure；7-1, metal o-ring；7-1-1, pressure-bearing cavity portion；7-1-2, elastic packing tongue Portion；7-1-3, recessed portion is thinned；7-1-4, metal sealing tooth；7-2, spirotallic gasket；8, valve seat；9, wave mode circle；10, gasket；11, Steam exhaust structure body；11-1, main valve condense water chamber；12, connecting tube；13, auxiliary valve body；14, valve rod；14-1, valve stem seal face； 14-2, thermal compensation slot；15, guide's valve seat；15-1, water-resisting wall；15-2, auxiliary valve condense water chamber；16, auxiliary valve valve deck；16-1, water guide The conical surface；17, divided ring；18, compound gasket structure；18-1, metal flute profile pad；18-2, wound gasket；19, lower flange；20, upper method It is blue；21, gland steam exhauster；22, gland；23, auxiliary valve spring；24, support plate；25, column；26, fastening screw nut；27, adjusting cap；28, Push rod；29, driving device；30, internal resistance ease ring；31, extrernal resistance ease ring；32, V-type metal o-ring；33, c-type metal o-ring.

Specific embodiment

Technical solution of the present invention is further elaborated with two embodiments with reference to the accompanying drawing.

Embodiment one

It is the schematic diagram of product structure of the electromagnetic relief valve of the present embodiment as shown in Figure 4.

The side of main valve is arranged in the structure that the electromagnetic relief valve is main valve, auxiliary valve is split type, auxiliary valve, and the two passes through connection Pipe (12) is connected with necessary fixedly connected part, and the exhaust steam end of valve is located on the upside of main valve, is set to valve body of main valve (1) upper end Steam exhaust structure body (11) is the connecting flange with upper and lower flange end, and lower end flanges pass through bolt connection phase with valve body (1) upper end It connects simultaneously and compresses valve seat (8), upper flanges when installing with the gland steam exhauster of side disposed thereon for connecting；In valve body (1) The intracavitary main valve clack for being equipped with truncation and discharging main steam, upward, main valve clack is interior because being equipped in the direction of main valve clack sealing surface Main spool spring (3) thus valve assembly after main valve clack sealing surface can the sealing surface upwards with valve seat (8) lower end be adjacent to.Valve Guide's sealing structure is arranged in auxiliary valve, auxiliary valve body (13) by divided ring (17), lower flange (19) and upper flange (20) with Bolt connection structure is connected with auxiliary valve valve deck (16), is provided with gland steam exhauster outward in the intermediate exhaust passage of auxiliary valve valve deck (16) (21)；The upper end of auxiliary valve valve deck (16) is equipped with auxiliary valve spring (23), and the upper end of auxiliary valve spring (23), which presses against, to be mounted on At the lower end step plane of the support plate (24) on valve rod (14) top, make the close of guide's sealing structure positioned at valve rod (14) lower end Envelope pair is in be adjacent to state after assembly and installation；The upper end of valve rod (14) is provided with adjusting cap (27), adjusting cap after valve assembling (27) with fastening screw nut (26) and tight and fix its position after adjusting axial position；Inside is equipped with the driving dress of electromagnet (29) are set to be fixed on auxiliary valve with three root posts (25).

Main valve clack uses flap modular construction in the technical program.The working principle of valve is as follows: valve is in working condition When, the lumen of valve body (1) full of main steam (crossing hot vapour), steam by the gap between flap component (5) and guide sleeve (4) into Enter the inner space of flap component (5), while and passing through the inner cavity of connecting tube (12) entrance auxiliary valve body (13), high steam Pressure be acting upwardly on flap component (5) valve clack sealing surface (5-2) made to be pressed on the sealing surface of valve seat (8) and make valve Sealing is kept, while the pressure of high steam is also acting upwardly on valve rod (14) lower end and guide's sealing structure is made to keep sealing.When The pressure rise of main steam in superheater header and when being more than the set-pressure of electromagnetic relief valve, it is logical that pressure switch issues signal Crossing control system makes the electromagnet excitation in driving device (29) and acts, and is made on the downside of driving device (29) by transmission mechanism Push rod (28) quickly moves down and the valve stem seal face (14-1) of valve rod (14) lower end is pushed to open, after auxiliary valve is opened, flap The steam of component (5) inner space from auxiliary valve valve deck (16) intermediate exhaust passage and gland steam exhauster (21) rapidly be discharged, flap The upper end of component (5) is from sealing surface diameter to active force downward by steam in the annulus areal extent of flap component (5) outer diameter And open, then the upper surface of entire flap component (5) is reached fully open position rapidly by the down thrust of pressure medium and arranges Put steam；Flap component (5) is being opened and when discharge state, although still have steam from flap component (5) and guide sleeve (4) it Between gap and the space in flap component (5) into pressure passageway (5-8) is flowed to by the lower end outer flap (5-4), but due to valve The through-current capability of the direction will be noticeably greater than the through-current capability of above-mentioned gap location after bar sealing surface (14-1) is opened, and add flap Several are machined in the outer circle of component (5) has damping slot (5-7) (see Fig. 7) energy of retardation of appropriateness to the flowing of steam It is enough that the steam flow of inflow is suitably limited, thus interior be not likely to form of flap component (5) can allow the back pressure of its time seat, Therefore, flap component (5) can be stably maintained at fully open position in discharge state to guarantee the reliable discharge of superpressure steam simultaneously Avoid the vibration and abrasion of part.When main steam pressure is reduced to the preset blow pressure of electromagnetic relief valve, control system System, which issues signal, powers off electromagnet, push rod (28) retraction, under the action of auxiliary valve spring (23) spring force, valve stem seal face (14-1) is closed, gap of the steam between flap component (5) and guide sleeve (4) and by the lower end outer flap (5-4) into pressure Channel (5-8) is again introduced into the space in flap component (5), since the medium of flap component (5) inner cavity is noncurrent medium, Its static pressure can be higher than the static pressure of the swiftly flowing medium on the upside of flap component (5), and upper and lower pressure difference adds main valve bullet The thrust of spring (3) will push flap component (5) closing；After valve is closed, main valve and auxiliary valve will keep close by steam pressure Envelope.

The structural shape of valve body (1) is revolution figure, is welded by upper and lower two parts, at the middle part of valve body (1), if It is equipped with the support frame (2) for supporting and fixing the parts such as flap component (5), the outer ring (2-1) of the annular of support frame (2) is embedding It fills and is clamped between upper and lower two parts of valve body (1), the interior hub in middle section-(2-2) and support frame (2) of support frame (2) Circular passage between outer ring (2-1), passes through from bottom to top for medium；It is additionally provided between interior hub (2-2) and outer ring (2-1) Multiple dowels (2-3) (see Figure 17), make position of the interior hub (2-2) in valve body (1) be supported and be fixed.

In the present embodiment, the structure that attached the flap component (5) of thermal compensation function and elastic compensating function is valve One of main key problem in technology, technical solution are as follows: flap component (5) is by thermal valve valve (5-1) and outer flap (5-4) two parts structure At (Fig. 7), thermal valve valve (5-1) and outer flap (5-4) are revolution figure part, and the two is concentric arrangement, thermal valve valve (5-1) exists Outside, the two is integrated interior and outer flap (5-4) with threaded engagement connection, and is punched, is packed into from the outer circle of outer flap (5-4) Straight pin (5-6) is locking；Thermal valve valve (5-1) upper surface outer circumferential side is the valve clack sealing surface (5-2) of circular ring shape, and sealing surface is plane Seal style (see Fig. 8), thermal valve valve (5-1) is the back side of valve clack sealing surface (5-2) is provided with the conical surface, the semi-cone angle of the conical surface is 55 °, while the adjacent position on outer flap (5-4) on the outside of the above-mentioned conical surface is also provided with the conical surface of identical taper, when When flap component (5) is in the free state for being not loaded into valve, there are small gap, this implementations between the above-mentioned two adjacent conical surface The gap setting is t=0.06~0.08mm in example, and when flap component (5) are assembled on product and bear medium in use After pressure, two conical surfaces are in contact；Elastic groove (5-3), the elastic groove are additionally provided at the conical surface of the thermal valve valve (5-1) (5-3) includes upper and lower step plane and cylindrical surface, with round-corner transition between cylindrical surface and upper and lower step plane.Outer flap (5-4) is being provided with step surface at valve clack sealing surface (5-2) outer diameter, and the vertical height of the upper surface on the outside of the step surface is high In the vertical height of valve clack sealing surface (5-2).

As shown in figure 8, the setting of clearance t makes the cone end elasticity tongue at thermal valve valve (5-1) sealing surface position be in sealing surface There can be appropriate elastic bending deflection when compression, which can effectively improve the sealing performance of valve；This reality A technical solution is applied relative to two sides steam discharge, the major-minor valve integral structure for using similar thermal compensation and elastic compensating structure Existing electromagnetic relief valve product the increased elastic groove (5-3) of valve flap structure institute, the sky of high-temperature steam is accommodated in addition to can be used as Between to make sealing surface position in high the temperature difference for carrying out effective thermal compensation on the inside of the sealing surface of upper end, reducing sealing surface medial and lateral Deformation when warm operating condition obtains outside control, another effect is that the upper side of elastic groove (5-3) seals thermal valve valve (5-1) Tapering on the downside of face switchs to plane since conical surface middle section, has carried out effectively being thinned since conical surface middle section to the tapering, together When the present embodiment in two sides steam discharge of the thickness than using similar thermal compensation and elastic compensating structure at the elasticity tongue of cone end Existing electromagnetic relief valve product thermal valve valve cone end elasticity tongue at thickness have appropriate increase, make entire elastic groove (5-3) Upside can generate effective elastic bending deflection, rather than only by cone end elasticity tongue provide elastic compensating, elasticity Compensation ability obtains more significant enhancing, and the intensity at sealing surface position is also increased, and has when bearing back seat impact more preferable Reliability.Be set as between the cylindrical surface and side plane of elastic groove (5-3) with round-corner transition, can to avoid stress concentration and It cracks or fracture damage.Due to outer flap (5-4) at the outer diameter close to valve clack sealing surface (5-2) i.e. flexible deformation gap Outside is provided with step surface, and the vertical height of upper surface of the outer flap (5-4) on the outside of the step surface is made to increase and be higher than flap The vertical height of sealing surface (5-2), the upper surface-anti-sticking protective edge (5-10) on the outside of the step surface are higher by valve clack sealing surface (5-2) Height a as shown in Figure 8；With the existing electromagnetic relief valve for the two sides steam discharge for using similar thermal compensation and elastic compensating structure The main valve clack of product when opening discharge steam, meet because of opening to medium inflow direction by the flexible deformation gap in open configuration And be easy to make the small impurity particle in medium be caught in flexible deformation gap cause the sealing condition of main valve clack sealing surface by Unlike influencing, the present embodiment technical solution is provided with the anti-sticking protective edge (5-10) that height is higher than valve clack sealing surface (5-2), makes Flexible deformation gap on the downside of valve clack sealing surface (5-2) is hidden into the step surface on the outside of flexible deformation gap, is not straight It connects in the discharge-channel for being exposed to medium, thus is difficult to be discharged the small impurity particle blocking that may be mingled in medium, make The sealing reliability of valve is enhanced.

In the technical solution of the present embodiment, also at the upper end outer circle of the outer flap (5-4) of flap component (5) and thermal valve The corresponding height of elastic groove (5-3) on valve (5-1) is drilled with the aperture (5-5) (referring to Fig. 7) of multiple uniformly distributed perforations.

Elastic groove (5-3) on thermal valve valve (5-1) can be used as the space for accommodating high-temperature steam on the inside of the sealing surface of upper end Effective thermal compensation is carried out, when valve is in close state, due to being located at the thermal valve valve (5- on the downside of valve clack sealing surface (5-2) 1) the flexible deformation gap between outer flap (5-4) is in closed state because of compression, and high-temperature steam can be difficult to enter at this time It not can enter the space in elastic groove (5-3) completely even, prevent the thermal compensation function of flap component (5) from being played.This In the technical solution of embodiment, at elastic groove (5-3) on the outside of outside flap (5-4) increased perforation aperture (5-5) just It can solve this problem, high-temperature steam can swimmingly enter in elastic groove (5-3), make flap component (5) sealing surface position Thermal compensation function normally played, to make valve that can maintain preferable sealing performance for a long time under worst hot case.

Another key structure in the present embodiment technical solution is installation and the fixed structure of guide sleeve (4).Positioned at valve The outside of valve component (5), for flap component (5) guide-localization tubular guide sleeve (4), propped up with the orifice end of its lower end The circular cylindrical projection stop portion installation positioning (see Fig. 4) of support (2) upper end, the outer circle of guide sleeve (4) are equipped with the Step-edge Junction of annular Structure, the upper side of step structure are annular plane；It is clamped in the outside of valve seat (8), from valve seat (8) in valve body (1) and row On the inside of the lower plane of boss between vapour structural body (11) lower flange down, it is additionally provided with pressure rack (6), pressure rack (6) is revolution figure And the through-flow window of window-(6-1) of multiple uniformly distributed perforations is machined in outer circle, for medium by being flowed into inside outside (see Fig. 9), The upper and lower end face of pressure rack (6) is located at the boss lower plane on the outside of valve seat (8) and the circular ring shape platform in guide sleeve (4) outer circle On rank between plane.In addition, between the boss lower plane on the outside of the upper surface of pressure rack (6) and valve seat (8), and it is equipped with one The wave mode circle (9) of elasticity tension can be generated after compression.

Guide sleeve (4) is placed on support frame (2) upper end when valve assembles and is packed into pressure rack (6) on it, valve seat (8) After being loaded into and clamping between valve body (1) and steam exhaust structure body (11) lower flange, the installation of pressure rack (6) and guide sleeve (4) Position is just completely fixed.When valve steam discharge, steam enters in valve from valve body (1) lower end, passes through the interior hub (2- of support frame (2) 2) channel between outer ring (2-1) is upward, enters to the upper of flap component (5) at the through-flow window (6-1) on pressure rack (6) Side is simultaneously discharged by the access opening of valve seat (8).

Due to needing sufficiently to compress the boss lower plane on the outside of valve seat (8) by middle flange bolt after valve seat (8) assembly With the associated seal of the Multiple Combination sealing structure (7) at the concave mouth of valve body (1) upper end, to ensure the upper hold-carrying of valve body (1) External leakage will not occur for blue place, will not hold out against between the upper surface and valve seat (8) of pressure rack (6) when therefore, it is necessary to guarantee assembly.For Increase vibration and noise when preventing due to pressure rack (6), guide sleeve (4) are not compacted along axial direction in steam discharge, in the upper of pressure rack (6) Wave mode circle (9) are provided between end face and valve seat (8), pressure rack is made by the elastic force of wave mode circle (9) when valve seat (8) compresses (6) it is also moderately compressed simultaneously with guide sleeve (4).

After guide sleeve uses the above-mentioned installation fixed structure directly assembled, used with existing product to be interference fitted indentation Mode compare, the fixation of guide sleeve is more reliable, and assembly is more convenient, quick, and maintenance is also easier to, while the processing request of part Also it decreases.

In the technical solution of the present embodiment, in the lower end of auxiliary valve valve deck (16), it is provided with guide's valve seat (15) (see Figure 11), Guide's valve seat (15) is connected and sealed with auxiliary valve valve deck (16) by screw thread and sealing welding, and the weld seam of sealing welding is located on screw thread At the outer circle at end, auxiliary valve valve deck (16) and guide's valve seat (15) joint surface, guide's sealing surface that switching motion is executed on auxiliary valve is straight The lower part for being arranged on valve rod (14), being located at valve rod (14) is connect, is provided with and the valve of valve rod (14) lower part on guide's valve seat (15) The sealing surface of bar sealing surface (14-1) pairing；Valve stem seal face (14-1) is spherical surface, and the sealing surface on guide's valve seat (15) is then It dehisces the downward conical surface in direction, is coincide both when closing with tangent state, the sealing surface of guide's valve seat (15) in the present embodiment Cone angle is set as 60 °, the processing that the sealing surface of valve stem seal face (14-1) and guide's valve seat (15) passes through built-up welding and heap postwelding It is formed, the high rigidity cobalt-base alloys of equal built-up welding HRC >=50 of two sealing surfaces；The back side of valve stem seal face (14-1) is provided with annular Groove-thermal compensation slot (14-2)；From the outer diameter of valve stem seal face (14-1) toward having one section of cylindrical section, the cylindrical section again The increase of downward then outer diameter constitutes another section of cylindrical surface for valve rod (14) lower end bearing guiding, the sealing of first guide valve seat (15) The past cylindrical hole being arranged with and the above-mentioned cylindrical surface being oriented to for the bearing of valve rod (14) lower end cooperates in face；From guide's valve seat (15) toroidal cavity between the cylindrical section of the upside and valve stem seal face (14-1) outer diameter of above-mentioned cylindrical hole down is outside, bores There are uniformly distributed several through flow holes, is also drilled with uniformly distributed several through flow holes toward above-mentioned toroidal cavity in valve rod (14) lower end surface.

The structure of the split of valve rod and guide's flap relative to existing product, the technical program use above-mentioned valve rod With the overall structure of guide's sealing surface can overcome because the size of connection structure is smaller, guide's flap be fragile material, structure compared with Brought by complexity the problem of poor reliability；Valve stem seal face is formed by the way of built-up welding cobalt base hard alloy, can be made whole Body structure makes guide's sealing structure use reliability with higher, sealing surface while keeping preferable comprehensive mechanical performance The high rigidity cobalt base hard alloy of built-up welding HRC >=50 enables to obtain preferable resistance to compression, against corrosion, scour resistance at sealing surface, To make guide's sealing surface obtain more preferable, more longlasting sealing performance.The sealing surface of guide's valve seat (15) is designed as the conical surface, favorably In sealing surface diameter it is smaller, axial fasten power and also make sealing surface by amplification of the cone structure to power under lesser state Obtain enough seal pressures；The cone angle of usual conical surface seal is sealed by 60 °~70 ° designs, the present embodiment in order to improve guide Sealability at face processes sealing surface by 60 ° of relatively Small Tapers；Sealing pair uses spherical surface-conical surface structure, can make to seal Pair obtains state of more preferably coincideing, for the flat seal of existing product or the conical surface-conical surface sealing structure more Facilitate the sealing performance of improvement product.

The thermal compensation slot (14-2) of valve stem seal face (14-1) back side, by increasing valve stem seal face (14-1) back surface At a distance from the area and reduction high-temperature medium and uper side surface of high-temperature medium contact, more heats can be allowed to be communicated up, It is substantially reduced the temperature difference in the interior outside at sealing surface position, so as to make the uneven heat of valve stem seal face (14-1) at high temperature Deformation is controlled better and then enhances the sealing reliability of auxiliary valve guide sealing position and sealing life.

The structure setting of the technical program makes the lower end of valve rod (14) obtain reliable bearing positioning；It seals and ties in guide The side through flow hole and lower through flow hole that the lower part of structure is arranged simultaneously, with existing product only at guide frame aperture mode phase Than secondary valve flow area required when opening discharge steam is guaranteed, to ensure that the Valve opening velocity of valve can be more preferable Ground meets the needs of unit safety protection.

It is logical in the intermediate steam discharge for the auxiliary valve valve deck (16) being located on the upside of pilot valve seat (15) in the technical solution of the present embodiment The lower end in road is equipped with the conical surface-water guide conical surface (16-1) (Figure 11) for the toroidal that diameter increases down, the water guide conical surface (16-1) For the lesser conical surface of angle of taper, its semi-cone angle is by 7.5 ° of processing in the present embodiment；First guide valve seat (15) is located at above-mentioned lead The downside in water cone face (16-1) and auxiliary valve condensation water chamber (15-2) of the groove-for being equipped with opening up annular, auxiliary valve condensation water chamber Between the intermediate steam through flow hole of (15-2) and guide's valve seat (15), has and up extend on the inside of auxiliary valve condensation water chamber (15-2) , the water-resisting wall (15-1) of circular ring shape be separated by, the upper end outer diameter of water-resisting wall (15-1) is less than the interior of the lower end the water guide conical surface (16-1) Diameter, thus have certain through-flow gap between the upper end of water-resisting wall (15-1) and the lower end of the water guide conical surface (16-1), from auxiliary valve The condensed water that the hole wall of the intermediate exhaust passage of valve deck (16) flows down can flow into downwards along the surface of the water guide conical surface (16-1) In auxiliary valve condensation water chamber (15-2).

After discharge of steam, the steam being deposited in blow-off line and the intermediate exhaust passage of auxiliary valve valve deck (16) can be condensed gradually Condensed water is formed, condensed water will cause the inhomogeneous deformation of sealing surface and cause to leak after flowing back to guide's sealing surface position.This Embodiment condensed water container structure set in the lower end of auxiliary valve valve deck (16) and guide's valve seat (15) may insure to condense Water will not flow at guide's sealing surface: in the condensed water formed in the intermediate exhaust passage of auxiliary valve valve deck (16) and gland steam exhauster (21), This partial coagulation water flowed down along the hole wall of the intermediate exhaust passage of auxiliary valve valve deck (16) can be along the surface of the water guide conical surface (16-1) It fully flows into downwards in auxiliary valve condensation water chamber (15-2), since the bottom end of auxiliary valve condensation water chamber (15-2) is at a distance from sealing surface Relatively close, temperature is higher, thus the condensed water for flowing into auxiliary valve condensation water chamber (15-2) can rapidly or gradually gasify again；In addition a small amount of Suitable valve rod (14) surface decline condensed water, since the temperature of valve rod (14) lower section is higher, thus decline condensed water midway It can gradually gasify and can not reach at the sealing surface of valve rod (14) lower end.Therefore, by above-mentioned condensed water container structure energy It is enough reliably to solve the problems, such as that condensed water present in existing electromagnetic relief valve product influences the sealing of guide's sealing surface.Water guide cone Why face (16-1) is set as the lesser conical surface of angle of taper, is to consider to guarantee that condensation water energy flows downward and energy along the conical surface Enough enter auxiliary valve condensation water chamber (15-2), is flow at guide's sealing surface without dripping.

In the technical solution of the present embodiment, in valve seat (8) and valve body (1) installation position, i.e. the recessed of valve body (1) upper surface stops On the outside of mouth and valve seat (8) at the lower plane of boss, it is sealed using Multiple Combination sealing structure (7) (see Figure 14 and Fig. 4), institute The Multiple Combination sealing structure (7) stated includes the metal o-ring (7-1) and spirotallic gasket (7-2) of circular ring shape.The metal The section of sealing ring (7-1) is structure symmetrical above and below, and the inner radius of leaning on of metal o-ring (7-1) is pressure seal section, described Pressure seal section includes pressure-bearing cavity portion (7-1-1), elastic packing tongue (7-1-2) and thinned recessed portion (7-1-3): pressure-bearing is empty Cavity portion (7-1-1) is the level trough of the circular ring shape cut out in outward direction in the middle part of the internal diameter by metal o-ring (7-1), circular ring shape The top of slot is that the arc-shaped stress to reduce slot root is concentrated, improves reliability；Metal o-ring (7-1) upper and lower surface is close Entity between the annular surface and pressure-bearing cavity upper and lower surface of internal side diameter constitutes elastic packing tongue (7-1-2)；Metal o-ring (7-1) upper and lower surfaces are located at the annular section on the outside of elastic packing tongue and being inwardly recessed and constitute thinned recessed portion (7-1-3). Upper and lower surfaces in the side of the close outer diameter of metal o-ring (7-1) are provided with the ladder plane for the annular being inwardly recessed, and Spirotallic gasket (7-2) is placed in the recessed ladder plane.It is located at spirotallic gasket (7-2) in metal o-ring (7-1) And the upper and lower surface between the pressure seal section of internal diameter side, it is additionally provided with tooth form seal section, the tooth form seal section is It is left after carving the groove equidistantly arranged except several in the upper and lower surface of metal o-ring (7-1) wide narrow concentric The metal sealing tooth (7-1-4) that anchor ring is formed.The elastic packing tongue (7-1-2) of pressure seal section and valve body (1), valve seat (8) the upper-lower seal surface contacted, when being in non-pressured state before assembly, recessed portion is slightly above thinned in the sealing surfaces The surface of metal sealing tooth (7-1-4) on the outside of (7-1-3), the in the present embodiment upper following table of elastic packing tongue (7-1-2) The height that face is higher than the surface metal sealing tooth (7-1-4) is 0.15mm.

After valve assembly, the elastic packing tongue (7-1-2) of metal o-ring (7-1) because being slightly above medial plane, thus Certain elastic bending can be generated after compression and with it is convex on the outside of the concave mouth sealing plane of valve body (1) upper surface and valve seat (8) The lower end sealing plane of platform is adjacent to, and forms initial sealing than pressure；When valve is in running order, it is located at pressure-bearing cavity portion (7- 1-1) high-pressure medium at place pushes elastic packing tongue (7-1-2) to be more closely affixed to valve body (1) and the sealing of valve seat (8) is flat Face generates preferable sealing effect；The purpose that recessed portion (7-1-3) is thinned is set, is to enhance elastic packing tongue (7-1- 2) elastic bending ability.In order to enhance sealing performance and sealing reliability, in addition also set up except above-mentioned pressure seal section Tooth profile metal seal section and wound gasket seal section form multi-sealing structure；The surface groove at the position metal sealing tooth (7-1-4) Effect be to reduce contact area, improve seal pressure to improving sealability；Spirotallic gasket (7- set by outermost 2) wound gasket seal section, the outermost auxiliary sealing structure as Multiple Combination sealing structure are constituted.

Compared with the structure that existing product is sealed using V-type metal o-ring or c-type metal o-ring, Multiple Combination is used instead Sealing structure (7) greatly improves the sealing performance of valve seat (8) and valve body (1) installation position and sealing reliability；Spirotallic gasket With the buying of metal o-ring or manufacturing cost that are formed by machining well below V-type or c-type metal o-ring Import price, along with sealing reliability can improve a lot after use Multiple Combination sealing structure of the invention, thus valve The maintenance cost of door also will be greatly reduced.

Sealing structure at auxiliary valve body, valve deck: as shown in Figure 15 and Fig. 4, auxiliary valve body (13) and the auxiliary valve on the upside of it Sealing between valve deck (16) uses compound gasket structure (18), and the compound gasket structure (18) is by tooth profile metal pad (18- 1)+wound gasket (18-2) composition, two kinds of gasket concentric arrangements, tooth profile metal pad (18-1) exist in inside, wound gasket (18-2) Outside is placed at the seam allowance plane of auxiliary valve body (13) upper end.

Since the diameter of auxiliary valve body, valve bonnet seal position is relatively small, and in work condition state the position temperature Can be lower than valve body of main valve, the temperature at valve base sealing position, thus technical solution of the present invention is in auxiliary valve body, valve bonnet seal position Using above-mentioned relatively simple combination sealing gasket construction.Existing product is wound using V-type metal o-ring or soft graphite Pad as auxiliary valve body, the sealing element at valve bonnet seal position, V-type metal o-ring due to valve body and valve bonnet seal surface Contact area is small (essentially line contact condition), and the hardness decline of valve body, valve bonnet seal surface, connects with metal o-ring when high temperature Decline specific contact pressure because generating plastic deformation at contacting surface, will lead to sealing reliability reduction；And wound gasket be used alone in Its sealing reliability can not generally be met the requirements when high temperature and high pressure condition.Said combination gasket construction uses flute profile pad and twines Around pad side by side use formed dual-seal, sealability and sealing reliability had compared with the sealing structure of existing product it is larger Improve.

The structure of valve deck and valve rod top: the upper end of auxiliary valve valve deck (16) is provided with gland (22) (see Figure 16), gland (22) pacified on auxiliary valve valve deck (16) with the outer circle of its lower end with the inner hole of auxiliary valve valve deck (16) upper end and positioning, with screw Dress is fixed；Upper section inner hole and valve rod (14) the outer circle cooperation of gland (22) constitute the bearing guide surface of valve rod (14) upper end.Gland (22) aperture of lower section inner hole is greater than valve rod (14) outer diameter of a circle, is provided in the lower section inner hole of gland (22) in valve rod The vapor-proof escape structure for preventing steam from escaping from auxiliary valve valve deck (16) upper end when sealing surface (14-1) is opened, the vapor-proof Escape structure is staggered and is constituted by internal resistance ease ring (30) and extrernal resistance ease ring (31), in the present embodiment, is provided with three resistance ease rings, Configuration mode uses: internal resistance ease ring+extrernal resistance ease ring+internal resistance ease ring combination；It is omited when the internal diameter processing of internal resistance ease ring (30) The small outer diameter in valve rod (14), extrernal resistance escape ring (31) outer diameter processing when the slightly larger than lower section inner hole of gland (22) it is interior It is splitted with wire cutting and certain spring expanding or contraction can be generated in the side of diameter, two kinds of resistance ease rings；When Product Assembly, phase The cutting seam of adjacent two resistances ease ring, which is staggered 120 °, to be packed into.

The lower end of valve rod (14) is supported and is determined with the bearing guiding circular hole being arranged on the downside of guide's valve seat (15) conical seal (contact) face Position, upper end is then with the bearing of upper section inner hole and positioning of gland (22).Vapor-proof escape structure is by internal resistance ease ring (30) and extrernal resistance Ease ring (31) is come when preventing discharge of steam and auxiliary valve is just in case steam is from auxiliary valve valve deck (16) and valve rod (14) when leaking It is escaped at the mating surface at end, the lower section inner hole of internal resistance is escaped between ring (30) and valve rod (14), extrernal resistance is escaped ring (31) and gland (22) Between be interference fit very close to each other, steam can be prevented to flow upwards out；Two kinds of resistances ease rings because side by with wire cutting It splits, certain spring expanding or contraction can be generated, the opening and closing of valve rod (14) is influenced due to without causing stuck.With it is existing The structure of product is compared, and the present embodiment increases above-mentioned vapor-proof escape structure in the valve deck upper end of auxiliary valve, can effectively be hindered Only steam escapes, and is mitigated or eliminated on the possible influence of production environment, and increase driving device (29) and auxiliary valve spring (23) functional reliability.

Flow field when in order to make discharge of steam in valve is more reasonable, the interior hub (2-2) of support frame (2) rear surface, The position at the medium inlet end of face valve body (1), be provided with taper, by the plane tangent with interior hub (2-2) circular arc turn round It is formed by, downwardly projecting lower spreader (2-4) (see Figure 17 and Fig. 4)；It is also set at the middle part of the upper surface of thermal valve valve (5-1) Be equipped with taper, by with the upper transverse plane of thermal valve valve (5-1) it is tangent circular arc revolution be formed by, cone cell protruding upward point Flow cone (5-9) (Fig. 7)；In addition, connecting the section shape of interior hub (2-2) and the dowel (2-3) of outer ring (2-1) on support frame (2) Shape is also configured as the kidney ellipsoid with low flow resistance characteristic.

At shunting when the upside in the access road hole of valve body (1), the lower end of support frame (2) they are steam flowings, flap group The upper end of part (5) is that steam liquidates mixing and the position that turns upwards towards radially inward, and the dowel (2-3) of support frame (2) is attached Close is also the more complex position of steam flow field, and steam at high discharge can generate more serious vortex, meeting when flowing through these positions Enhance vibration and noise caused by discharge of steam.The above-mentioned increased flow dividing structure of technical solution institute or fairing ace, Swiftly flowing steam can be guided, vortex intensity when discharge of steam can be obviously reduced, when reducing discharge of steam Vibration and noise.

Embodiment two

It is the schematic diagram of product structure of the electromagnetic relief valve of the present embodiment as shown in Figure 5 and Figure 6.What the present embodiment was addressed Electromagnetic relief valve split type, top bilateral steam discharge electromagnetic relief valve for the auxiliary valve of main valve.The driving device that auxiliary valve top is configured (29), the driving device of active force can be provided using by electromagnet, can also uses and is provided by solenoid valve control pneumatic mechanism The driving device of active force；When valve steam discharge, driving device (29) passes through push rod (28) driving stem (14) movement on the downside of it And make valve opening.

The valve mechanism technical solution of the electromagnetic relief valve of the present embodiment, the only tool of the steam exhaust structure body (11) of main valve upper end Body, which implements the implementation structure of structure and steam exhaust structure body (11) lower end and valve seat (8) junction and embodiment one, larger difference Different, remaining each position is in terms of structure or structural principle and no significant difference in addition to this, therefore the present embodiment only has to aforementioned The specific structure of larger difference makees related discussion, remaining is the same as example 1 or similar structure is then only made summary or do not applied It states.

It in the upside of valve body (1) and valve seat (8), is provided with steam exhaust structure body (11), the centre of steam exhaust structure body (11) is hung down Straight channel lower part is connected by the connecting flange of lower end with bolting connection structure with valve body (1) upper end, while steam exhaust structure body (11) and with the step plane at its lower end surface plane on the boss on the outside of valve seat (8), the centre of steam exhaust structure body (11) are compressed Vertical channel shunts to form triplet type structure toward arranged on left and right sides direction upwards, and left and right horizontal channel is arranged in both ends end symmetric There is connecting flange, the connection of the steam discharge elbow of when for installing and two sides；Steam exhaust structure body (11) left and right horizontal channel is at both ends With the taper being gradually reduced near aperture to interior diameter.Steam exhaust structure body (11) is processed using stainless cast steel part, among it Vertical channel is smoothly transitted using the arced flow path being increasingly turned to the turning point of two sides horizontal channel and on the top for shunting position Hold the shunting cambered surface of self-assembling formation taper.

The present embodiment is simultaneously equipped with condensed water container structure (see Figure 10) between steam exhaust structure body (11) and valve seat (8), institute The condensed water container structure stated is to be provided with annular cavity-main valve between steam exhaust structure body (11) lower end and valve seat (8) to coagulate It bears water room (11-1), main valve condensation water chamber (11-1) is by plane on boss on the outside of valve seat (8) and the valve seat (8) on the upside of it The stepped hole that outer circle is processed with steam exhaust structure body (11) intermediate vertical channel lower end is surrounded；It hangs down among steam exhaust structure body (11) Straight channel lower end is located at the aperture on the upside of valve seat (8) at adjacent regions and is greater than valve seat (8) intermediate channel hole upper end toroidal hole Aperture at mouthful；At the outer circle of valve seat (8) upper end between the lumen orifice of steam exhaust structure body (11) intermediate vertical channel lower end, and there are The gap of annular makes main valve condensation water chamber (11-1) be connected with the inner cavity of steam exhaust structure body (11)；In addition, in valve seat (8) quilt On the boss that steam exhaust structure body (11) compresses at plane, and it is provided with gasket (10).

When valve steam discharge, driving device drives guide's sealing structure in auxiliary valve to act, by the connection of the major-minor valve of connection Pipe (12) makes the flap component (5) in main valve lose back pressure, flap component (5) to open downwards under the action of pressure medium on it Open discharge steam.The steam of discharge is upward through valve seat (8) intermediate channel hole and steam exhaust structure body (11) intermediate vertical channel, is arranging Vapour structural body (11) top turns to left and right horizontal direction, is discharged by the steam discharge elbow that both ends connect.On steam exhaust structure body (11) Portion's turning point is due to having nature due to using arced flow path using the arced flow path being increasingly turned to and shunting position top tape The tapered shunting cambered surface of formation, enables steam olderly flowage, can be avoided steam at shunting position and generates stronger vortex And enhance vibration and noise when steam discharge.Steam discharge when valve restores to closed state, after discharge of steam from muffler down The a large amount of steam retained in pipeline gradually condense after in addition to a part can connect disk by gland steam exhauster condensate and enter drain water piping, by In steam exhaust structure body (11) vapor discharge channel from existing product used by upwards in line mode be improved to be folded to a left side Right horizontal direction and in such a way that steam discharge elbow discharges upwards, and the horizontal channel both ends of steam exhaust structure body (11) have aperture The lower part of the small taper of mouth while steam discharge elbow can have drain nozzle in big, thus connect disk toward lower portion institute from gland steam exhauster condensate The condensed water of generation will not enter at the intermediate vertical channel of steam exhaust structure body (11)；In addition, steam exhaust structure body (11) lumen Generated a small amount of condensed water can pass through outside valve seat (8) upper end along the inner wall in steam exhaust structure body (11) intermediate vertical channel Annular gap and entrance main valve condensation water chamber (11-1) at justifying between steam exhaust structure body (11), since main valve condenses water chamber The surface of the valve seat (8) of (11-1) inner wall is influenced temperature by the heat transfer of lower part high-temperature steam can be higher, thus it is solidifying to enter main valve Bearing water the condensed water in room (11-1) again can gradually vaporize and in disperse to steam exhaust structure body (11) and gland steam exhauster cavity；Valve seat (8) inner hole not will form condensed water because of temperature higher (being higher than 100 DEG C) thus on its surface.

When flap component (5) is in close state, when thering is oxidation corrosion product and impurity to flow down with condensed water, same meeting Enter drain water piping from the drainage hole of steam discharge elbow lower end with condensed water or be trapped in steam discharge elbow, if there is a small amount of oxidation It, also can be with condensed water along steam exhaust structure body (11) intermediate vertical channel when corrosion product etc. is interior into steam exhaust structure body (11) Inner wall is flowed into and is accumulated in main valve condensation water chamber (11-1), without flowing to and being trapped near main valve sealing surface；In this base On plinth, since steam exhaust structure body (11) is processed using stainless cast steel part, thus also no longer there is oxidation corrosion product and fall to master Problem near valve sealing surface.Therefore, technical solution of the present invention eliminates existing top row vapour electromagnetic relief valve product and is easy The problem of existing oxidation corrosion product and impurity bring influence to valve seal.

The content that this specification is not described in detail belongs to the prior art well known to professional and technical personnel in the field.

Technical solution of the present invention is illustrated in conjunction with the accompanying drawings and embodiments above, but these attached drawings and explanation are not It makes sense to limit the scope of the present invention.Those skilled in the art should know that the present invention is not by above-mentioned implementation The limitation of example and attached drawing, protection scope is defined by appended claims, any without departing from the claims in the present invention Book define in the range of various changes, modification be formed by technical solution, all without departing from spirit and technology of the invention Essence, still can belong within scope of the presently claimed invention.

Claims (4)

1. a kind of power station main steam system top steam discharge electromagnetic relief valve, the electromagnetic relief valve are the split type knot of major-minor valve Structure, auxiliary valve are installed on main valve side, and the exhaust steam end of valve is located at the top of main valve, and the upper end of valve body of main valve (1) is provided with row The downside of vapour structural body (11), steam exhaust structure body (11) is connected with valve body (1) upper end with flange while and compressing valve seat (8)； Valve body (1) is to turn round three-dimensional-structure, be welded by upper and lower two parts, is equipped with support frame (2) at the middle part of valve body (1), support Between embedding upper and lower two parts for being sandwiched in valve body (1) in outer ring (2-1) of the annular of frame (2), the interior hub in middle section-of support frame (2) Circular passage between (2-2) and outer ring (2-1), passes through from bottom to top for medium, interior hub (2-2) and outer ring (2-1) it Between be equipped with multiple dowels (2-3), so that position of the interior hub (2-2) in valve body (1) is supported and is fixed；Valve is filled by driving It sets and drives auxiliary valve events and open the main valve clack in main valve, it is characterised in that: main valve clack uses flap modular construction, flap group Part (5) is made of thermal valve valve (5-1) and outer flap (5-4), and thermal valve valve (5-1) and outer flap (5-4) are revolution figure part, The two be concentric arrangement, thermal valve valve (5-1) inside and outer flap (5-4) outside, the two is simultaneously integrated with threaded engagement connection；Heat Flap (5-1) upper surface outer circumferential side is the valve clack sealing surface (5-2) of circular ring shape, and thermal valve valve (5-1) is in valve clack sealing surface (5-2) Back side is provided with the conical surface, while the adjacent position on outer flap (5-4) on the outside of the above-mentioned conical surface is also provided with identical cone The conical surface of degree, when free state when flap component (5) are in unassembled, there are between small between the above-mentioned two adjacent conical surface Gap, and then two conical surfaces are in contact when flap component (5) is in work condition state compression；At the conical surface of the thermal valve valve (5-1) It is additionally provided with elastic groove (5-3), the elastic groove (5-3) includes upper and lower step plane and cylindrical surface, cylindrical surface and upper and lower With round-corner transition between step plane；Vertical height of the outer flap (5-4) in the upper surface at valve clack sealing surface (5-2) outer diameter Degree is higher than the vertical height of valve clack sealing surface (5-2)；Positioned at the outside of flap component (5), for flap component (5) guide-localization Tubular guide sleeve (4), lower end installs positioning with cylindrical positioning surface on support frame (2), in the outer circle of guide sleeve (4) Equipped with step surface, the boss lower plane on the outside of valve seat (8) is additionally provided with pressure rack (6) down, and pressure rack (6) is revolution figure and outside The through-flow windows of window-(6-1) of multiple perforations is machined on circle for medium by flowing into inside outside, the upper and lower end face point of pressure rack (6) Not Wei Yu on the step on the boss lower plane and guide sleeve (4) outer circle on the outside of valve seat (8) between plane,

Steam exhaust structure body (11) positioned at valve body of main valve (1) upper end has upper and lower end connecting flange, and upper end connecting flange is for pacifying It is connected when dress with the gland steam exhauster of side disposed thereon,

Steam exhaust structure body (11) positioned at valve body of main valve (1) upper end is triplet type structure, and in-between vertical channel is upwards toward left and right Two side directions shunt to form horizontal channel, and left and right horizontal channel is provided with connecting flange in both ends end symmetric, when for installing It is connected with the steam discharge elbow of two sides；The material of steam exhaust structure body (11) is stainless steel material, and left and right horizontal channel is in both ends band There is the taper being gradually reduced near aperture or aperture to interior diameter；It is set between steam exhaust structure body (11) lower end and valve seat (8) There is cavity-main valve condensation water chamber (11-1) of annular, main valve condensation water chamber (11-1) on boss on the outside of valve seat (8) by putting down The stepped hole of face and valve seat (8) outer circle and steam exhaust structure body (11) intermediate vertical channel lower end on the upside of it is surrounded；Steam discharge knot Structure body (11) intermediate vertical channel lower end is located at the aperture on the upside of valve seat (8) at adjacent regions and is greater than valve seat (8) intermediate channel hole Aperture at the aperture of upper end, at the outer circle of valve seat (8) upper end between the lumen orifice of steam exhaust structure body (11) intermediate vertical channel lower end There are the gaps of annular, and main valve condensation water chamber (11-1) to be made to be connected with the inner cavity of steam exhaust structure body (11)；It is arranged in valve seat (8) At plane and gasket (10) are provided on the boss that vapour structural body (11) compresses；Sealing at valve body (1) and valve seat (8) mounting surface Using Multiple Combination sealing structure (7), the Multiple Combination sealing structure (7) includes the metal o-ring (7-1) of circular ring shape With spirotallic gasket (7-2)；The section of the metal o-ring (7-1) is structure symmetrical above and below, and metal o-ring (7-1's) leans on Inner radius is pressure seal section, and the pressure seal section includes the circle by cutting out outward in the middle part of metal o-ring (7-1) internal diameter The pressure-bearing cavity portion (7-1-1) of annular, metal o-ring (7-1) upper and lower surface is on the annular surface and pressure-bearing cavity of internal side diameter Elastic packing tongue (7-1-2) that entity between lower surface is constituted, that metal o-ring (7-1) upper and lower surface is located at elasticity is close The thinned recessed portion (7-1-3) of flap portion outside and the annular being inwardly recessed；The one of the close outer diameter of metal o-ring (7-1) The upper and lower surface of side is provided with the ladder plane for the annular being inwardly recessed and is placed with wound gasket in the recessed ladder plane Piece (7-2)；It is upper between the pressure seal section positioned at spirotallic gasket (7-2) and by internal diameter side of metal o-ring (7-1) Lower surface is additionally provided with tooth form seal section, and the tooth form seal section removes for the upper and lower surface in metal o-ring (7-1) at quarter The metal sealing tooth (7-1-4) that the wide narrow concentric circles anchor ring left after several grooves equidistantly arranged is formed；Pressure The upper-lower seal surface that the elastic packing tongue (7-1-2) of power seal section is contacted with valve body (1), valve seat (8) is in front of assembly When non-pressured state, the sealing surfaces are slightly above the table for the metal sealing tooth (7-1-4) being thinned on the outside of recessed portion (7-1-3) Face.

2. power station main steam system according to claim 1 top steam discharge electromagnetic relief valve, it is characterised in that: auxiliary valve valve Sealing between body (13) and auxiliary valve valve deck (16) on the upside of it uses compound gasket structure (18), the compound gasket structure (18) be made of tooth profile metal pad (18-1)+wound gasket (18-2), two kinds of gasket concentric arrangements, one inside another Outside is placed at the seam allowance plane of auxiliary valve body (13) upper end.

3. power station main steam system according to claim 1 top steam discharge electromagnetic relief valve, it is characterised in that: in auxiliary valve The upper end of valve deck (16) is provided with gland (22), and gland (22) is matched with the outer circle of its lower end and the inner hole of auxiliary valve valve deck (16) upper end It closes and positions, fixation is installed on auxiliary valve valve deck (16) with screw；The upper section inner hole and valve rod (14) outer circle of gland (22) cooperate Constitute the bearing guide surface of valve rod (14) upper end；The aperture of the lower section inner hole of gland (22) is greater than valve rod (14) outer diameter of a circle, It is provided in the lower section inner hole of gland (22) and prevents steam from auxiliary valve valve deck (16) when valve stem seal face (14-1) is opened The vapor-proof escape structure of evolution is held, the vapor-proof escape structure is by internal resistance ease ring (30) and extrernal resistance ease ring (31) staggered row Column are constituted, and the internal diameter of internal resistance ease ring (30) is slightly smaller than the outer diameter processing of the outer diameter of valve rod (14), extrernal resistance ease ring (31) when processing When the slightly larger than lower section inner hole of gland (22) internal diameter, the sides of two kinds of resistance ease rings are splitted with wire cutting and can generate one Fixed spring expanding or contraction.

4. power station main steam system according to claim 1 top steam discharge electromagnetic relief valve, it is characterised in that: supporting The rear surface of the interior hub (2-2) of frame (2), the medium inlet end of face valve body (1) position, be provided with taper, by with it is interior The circular arc revolution of the plane tangent of hub (2-2) is formed by, downwardly projecting lower spreader (2-4) is in the upper of thermal valve valve (5-1) Be also equipped in the middle part of end face taper, by with the upper transverse plane of thermal valve valve (5-1) it is tangent circular arc revolution be formed by, upwards The spreader (5-9) of the cone cell of protrusion；In addition, connecting the dowel (2-3) of interior hub (2-2) and outer ring (2-1) on support frame (2) Cross sectional shape be also configured as the kidney ellipsoid with low flow resistance characteristic.