DE2533519A1 - Combined emergency stop and control valve for steam turbine - has common control rod for both seats producing inverse opening effect - Google Patents

Abstract

The multi-purpose valve is used mainly for a steam turbine and consists of a common housing containing a high speed valve and a control valve with coaxial spindles. It has three successive chambers: inlet (1) outlet (2) and extraction (3). The boiler connects (17) to the inlet, and the turbine to the outlet. The steam blowout valve connects to the extractor chamber (3) which exhausts to the condenser. A control cylinder and piston (20, 21) with biasing spring (22) are positioned at each end of the housing, for axial movement of the rods (4, 5). The valve plugs are connected by the central section of rod, so that their opening and closing movements are interdependent and opposite. Admission of pressurised fluid causes movement in opposition to spring-biasing.

Description

BBC

BROWN, BOVERI & CLE ■ AKTIENGESELLSCHAFT

MANNHEIM BROWN BOVERI

Mp.no. 594/75 Mannheim, July 17, 1975

ZFE / P1- ¥ g / Bt

Very purposeful

The invention relates to a multi-purpose valve, in particular for Steam turbines, with at least one inflow and outflow space for the medium flowing through as well as at least one quick-closing and control valve each, which has a common housing, the valve body of which is arranged coaxially to one another and independently of one another by means of a tappet on a common one Act on the valve seat or on correspondingly assigned separate valve seats.

Between pressure generators and pressure consumers, e.g. between steam boilers and steam turbines, there are often combined quick-action and built-in control valves. The control valve regulates the amount of steam flowing into the turbine, while the Quick-closing valve is used to quickly separate the turbine from the steam boiler if this is necessary for operational reasons should be (CH-PS 303 774). Now there are often considerable in the parts of the system between the quick-acting closing valve and the turbine Amounts of steam are stored, despite rapid closing the control and quick-closing valves flow off via the turbine. It is often desirable to allow this amount of steam to pass through by preventing the turbine. In such cases, the connection between the quick-acting valve and the turbine can be switched off.

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Bladder valve can be connected, in the event of an emergency shut-off is opened and keeps the steam still contained in the shutdown system parts away from the turbine and closes discharges a condenser. Because this blow-off valve tightens the steam condenser from the system during turbine operation must separate, it requires a considerable effort, especially at high steam temperatures and / or steam pressures. The cost of this blow-out valve is in the order of magnitude that of the quick-closing and regulating valve is equivalent to. This is caused by the cost of the valve housing, high quality and therefore high quality for its manufacture expensive materials such as cast steel must be used. On the other hand, this blow-off valve is used during the The life of the turbine is not used very often, it is therefore particularly important its construction costs including the To keep construction costs for the actuators as small as possible.

The invention is now based on the object of a multi-purpose valve of the type mentioned in such a way that it has a simple structure and little additional effort in the case of the Quick closing also for the discharge of the quantities of working medium or steam present in the shut-off system parts can be used. In addition, the valve should be operationally reliable and meet the respective operational requirements.

This object is achieved in that in the Housing a blow-off valve connected to the discharge space is provided, the valve body is coupled to the valve body for quick closing to a shuttle valve in such a way, that when the quick-acting valve is closed, a connection from the discharge chamber to a blow-out chamber is released and when it is open Quick-closing valve is blocked. The arrangement of the

Pat 4 F 1 (6? 0 10000 / KE)

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Blow-out valve in the housing of the multi-purpose valve, the effort compared to separate design of these valves is already considerable reduced and the coupling of the two valve bodies simplifies and also makes their control cheaper.

An advantageous development of the invention now consists in that at least the main directions of movement of the valve body of the blowout valve when opening and the valve body for the Quick closing when closing are the same as each other. Both valve bodies can thus be coupled directly, with the under With the aid of the medium pressure, the valve body closes the valve body of the blow-off valve for quick-closing without significant external effort opens. Since the outflowing medium flows against the sealing side of the discharge valve body, The opening of the blow-out valve is also supported.

To a simple structure of the housing as well as an uncomplicated To achieve coupling of the two valve bodies, it has proven itself when the valve body of the blow-out valve is coaxial to the Valve body for quick closing at the outflow end of the preferably essentially also equiaxed connection between Outflow and exhaust space is provided. To further simplify the structure, it is recommended that the valve body of the blow-off valve and the valve body for quick-closing in the case of equilateral, e.g. coaxial nested arrangement of the tappets, with an extension and with mutual, aligned arrangement of the tappets over the corresponding plunger itself are connected to one another.

According to a further embodiment of the invention, the plunger or the plunger carrying the valve body for the blow-off valve Extension in the area of the connection in a warehouse.

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In this case it is particularly advantageous if the bearing is mounted centrally in one at the inflow end of the connection and conical projection protruding into the outflow space is provided, with channels machined in the projection Help to form the connection between the discharge space and the discharge space. The conical surface of the projection forms a kind of guide surface for the medium flowing through during normal operation, so that the pressure loss of the valve is reduced. Those incorporated into the projection, preferably directed towards the center of the free cross section of the outflow space Channels also allow the medium to flow away largely without loss when the blow-out valve is open.

Further advantages of the invention emerge from the following description of exemplary embodiments in connection with the drawings, which show the following schematically:

Fig. 1 is a central vertical section through the subject matter of the invention, the plungers on opposite sides Sides of the housing are led out and

FIG. 2 shows the object of FIG. 1 in a central vertical section with plungers lying one inside the other on the same side.

The same parts are given the same reference symbols in the individual figures Mistake.

In the housing 8 of the multi-purpose valve there is an inflow space 1 at the top, in the middle a discharge space 2 and below a discharge space 3 incorporated, the housing and the spaces essentially are designed to be rotationally symmetrical. At the inflow space 1 is a connection 17 for a pressure medium generator, e.g. a steam boiler, provided, the outflow space 2 has a connection

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for a pressure medium consumer, e.g. a turbine, while a blow-out connection 18 is provided on the blow-out space 3 is. When used in steam turbine systems, a steam condenser is connected to the exhaust chamber. All connections In the present exemplary embodiment, have a circular cross-section, the centers of which are in a vertical plane lie, with the connections 17, 18 in the same direction and the connection 19 in the opposite direction. Of the Inflow space 1 is connected to the outflow space via a rotationally symmetrical insert 26 which has a central throughflow opening 29 2 connected. The upper rounded end of the insert 26 carries the valve seats. It can be used for the rule and Quick-closing valve a common valve seat can be provided, which is formed by the upper end of the insert 26, preferably however, two separate valve seats 9, 30 are provided which are let into the insert 26.

A projection 15, which is directed towards the central throughflow opening 29 of the insert 26 and which is formed by channels, protrudes into the outflow space 2 is penetrated, which the connection 12 between the outflow space 2 and the blow-out space 3 when the valve body 11 is open educate. The valve seat of the blow-out valve 10 is provided at the lower end of the connection. In the inflow space 1 is a Valve body 7 provided for the regulation in the form of a pot that is open at the bottom, the sealing edge of which is on the valve seat 9 is directed. Within the valve body 7, a valve body 6 for the quick closing is coaxial and concentric arranged, the sealing edge acts on the associated valve seat.

In the blow-out space 3 there is a valve body 11 for the blow-out provided, the sealing edge of which points towards the sealing edges of the valve body 6, 7, and which cooperates with the valve seat 27. All essential parts of the multi-purpose valve, such as

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the spaces 1, 2, 3, the valve bodies 6, 7, 11, their associated seats, the connections between the individual spaces and the tappets 4, 5 xind the extension 13 are essentially approximately rotational symmetrically formed and provided with a common axis of symmetry 28.

In the embodiment according to Figure 1 are on opposite Ends of the valve housing 8 control cylinder 20 with control piston 21 and compression springs 22 for actuating the in cross section preferably round plungers 4, 5 are provided. The control fluid is fed in via openings 23.

The upper control piston 21 is connected to the valve body 7 for the regulation via the centrally mounted tappet 4. The insertion point into the housing is sealed with a housing cover. The lower control piston 21 is exactly like that upper control piston connected via a plunger 5 to the valve body for the quick closing. The plunger penetrates here the connection 12 and the throughflow opening 29. In addition, it is guided in the bearing 14 provided in the projection 15. on the plunger 5 is still the valve body 11 for the blow-out valve attached so that a rigid coupling between the valve bodies 6 and 11 is made. The distance between the sealing edges the valve body 6 and / i 1 must correspond to the distance between the valve seats 30 and 27 so that when the valve body is seated 6, the valve body 11 is fully open and vice versa.

In the embodiment according to FIG. 2, the control cylinders are 20 arranged on the same side of the valve housing. In order to now operate the valve bodies independently of one another can, the plunger 4 is hollow for the coaxial up-

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would take the plunger 5. That is, the plunger 5 is in the plunger 4 slidingly guided. To now the valve body 6 carried by the plunger 5 for the quick closing with the valve body 11 for the To couple blow-out, an extension 13 is provided between the two valve bodies, preferably in the form of a Extension of the ram?. The valve bodies are attached to the associated tappets with nuts and collars.

During operation, the pressure medium flows through the connection 17, the inflow chamber, when the quick-action and control valve is open 1, the throughflow opening 29 and the outflow space 2 to connection 19 for the pressure medium consumer. The flowing pressure medium would like the valve body 7 for the regulation bring it into its closed position, but this is prevented in the middle of the connected control piston 21, which is

so
tion 237 is supplied with control fluid so that the opening width of the valve corresponds to the respective desired flow rate. The pressure of the pressure medium also bears on the valve body 11 of the blow-off valve, but is held in the "closed" position and the quick-action valve ^{in the "open JI" position via the tappet 5 by the associated control piston 21} is tight, no pressure medium can pass into the blow-out space 3.

The outflow of the control fluid is used to trigger the quick-action closure released from the corresponding control cylinder, so that mainly the pressure medium flowing through the valve body 6 brings it into its closed position and thus interrupts the flow. By coupling the valve body β and the blow-out valve 10 is opened and the connection 12 from the outflow space 2 to the blow-out aura 3 is released. the Opening movement of the valve body 11 is caused by the on him onerous pressure of the flowing medium supported. Of the

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Terminal 19 leading to the consumer is thus connected to the terminal 18 connected for blowing out. In the case of the use of the multi-purpose valve according to the invention in turbine systems this means that the steam turbine is inevitably connected to a steam condenser in the event of a quick shutdown which absorbs the steam still present in the supply lines and thus relieves the turbine. Since the blading, large turbines, in particular, store considerable amounts of steam and in the spaces between individual blading parts of a turbine - such as water separators / reheaters - there are additional steam quantities, in addition to relieving the supply line, there is also a braking torque on the Turbine on, as part of the steam stored in or between the blades flows backwards and the Turbine running slows down.

To open the quick-acting valve, we d the control piston 21 of the corresponding control cylinder 20 by means of control fluid raised so that the Yentilkörper 11 of the blowout valve rests on its seat and the valve body 6 releases the flow again for the quick closing.

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Claims (1)

594- / 75 Claims Multipurpose valve, in particular for steam turbines, with at least one inflow and outflow space for the flowing medium Howie at least one quick-acting and control valve each having a common housing, the valve bodies of which are arranged coaxially with one another and independently of one another by means of a tappet on a common valve seat or on correspondingly assigned separate ones Acting valve seats, characterized in that a blow-out valve (10) connected to the outlet space (2) is also provided in the housing (8), the valve body (11) of which is coupled to the valve body (6) for quick-action closing to a shuttle valve in such a way that when the quick-action closing valve is closed, a connection (12) from the outflow space (2) to a blow-out chamber (3) is released and locked when the quick-action closing valve is open. Multipurpose valve according to claim 1, characterized in that that at least the main directions of movement of the valve body (11) of the blowout valve when opening and the The valve body (6) for the quick closing when closing are the same as one another. Multipurpose valve according to Claim 1 or 2, characterized in that the valve body (11) of the blow-out valve coaxially to the valve body (6) for the quick-action closure at the outflow end of the preferably also substantially coaxial connection (12) is provided between the outflow (2) and exhaust space (3). - 10 - INSPECTED Pat 4 F 1 (670.10000 / KE) 709 813/0371 594/75 4. Multi-purpose valve according to claim 3, characterized in that that the valve body (11) of the blowout valve and the Valve body (6) for quick closing in the case of equilateral, e.g. coaxial, nested arrangement the plunger (4,5) with an extension (13) (Fig. 2) and with a mutually aligned arrangement of the plunger (4, 5) are connected to one another via the corresponding plunger (5) itself. 5. Multi-purpose valve according to claim 4, characterized in that that the valve body (11) for the blow-off valve bearing plunger (5) or the extension (13) in the area of the connection (12) in a bearing (14) is. 6. Multipurpose valve according to claim 5, characterized in that the bearing (14) is centered in one, at the inflow end attached to the connection (12) and into the outflow space (2) protruding conical projection (15) is provided, wherein in the projection (15) incorporated channels (16) the connection (12) from the outflow space (2) to the exhaust space (3). Pat 4 F 1 C670.10000 / KE) 7 0 9813/0371