WO2020193702A1

WO2020193702A1 - Valve device

Info

Publication number: WO2020193702A1
Application number: PCT/EP2020/058555
Authority: WO
Inventors: Andreas Hellmann; Carsten PÜTTBACH; Viktor Schäfer; Olaf Tebbenhoff
Original assignee: Welland & Tuxhorn AG
Priority date: 2019-03-28
Filing date: 2020-03-26
Publication date: 2020-10-01
Also published as: DE102019108090A1; DE102019108090B4

Abstract

The invention relates to a valve device (1), in particular in the form of a control valve for power plants, comprising a housing (3) extending along a central axis (2), an inlet port (4) for introducing a fluid flow (5) into the housing (3), a movable piston (6), a sealing seat (7) paired with the piston (6), a rotationally symmetrical flow element (8), which is arranged in the housing (3), for treating the fluid flow (5), and an injection device (9) for injecting a cooling fluid. The flow element (8) has a plurality of flow channels (10), through which at least part of the fluid flow (5) can be conducted and in the course thereof can be accelerated and in this manner locally converted into atomizing flows (12). The flow element (8) is arranged relative to the injection device (9) such that the cooling fluid can be injected into the atomizing flows (12). The aim of the invention is to provide a robust valve device by means of which a reliable atomization of the coolant fluid is possible for vastly different fluid flow amounts. According to the invention, this is achieved in that the flow element (8) has a circumferential feed section (13) which protrudes into a flow region of the fluid flow (5) and by means of which part of the fluid flow (5) can be collected and fed to flow channels (10) paired with the feed section (13), and an inner wall (14) of the housing (3) has a circumferential annular protrusion (15) which is paired with the feed section (13), extends radially in the direction of the central axis (2), and by means of which at least part of the fluid flow (5) can be deflected in the direction of the feed section (13) of the flow element (8).

Description

Valve device

description

introduction

[01] The present application relates to a valve device according to the preamble of claim 1.

The valve device comprises a housing in which the other components of the valve device are arranged. The housing extends along a central axis and - apart from connecting lines and the like - is typically at least essentially rotationally symmetrical with respect to the central axis. The

The valve device comprises a movable piston which is suitable for sealingly cooperating with an associated sealing seat. In particular, the piston can be transferable between a closed position and an open position, a flow through the valve device being prevented when the piston is in its closed position and a flow limited by the sealing seat when the piston is in its open position

Flow cross-section is released so that a fluid flow can be conducted through the valve device. The piston can preferably be locked in any number of intermediate positions relative to the sealing seat, whereby an amount of the fluid flow can be regulated.

[03] An injection device, by means of which a cooling fluid can be injected into the fluid flow, is arranged inside the housing. Furthermore, the valve device comprises a flow element which comprises a plurality of flow channels. The

The flow element is preferably designed to be rotationally symmetrical and, as a rule, its axis of symmetry is aligned congruently with the central axis of the housing. The flow channels are preferably arranged in a circumferentially distributed manner on the flow element. The fluid flow is locally constricted at the flow channels, accelerated in the process and passed on through the flow channels. Here, at least part of the fluid flow is accelerated and in this way transferred into a number of atomization flows corresponding to the number of flow channels, the

Flow rate is increased. The flow element is arranged relative to the injection device in such a way that the injection of the cooling fluid into the

Atomization flows takes place. This is an atomization of the cooling fluid, the

is typically formed by water. State of the art

[04] Valve devices of the type described at the outset are already known in the prior art. They are used in particular in power plants as so-called bypass valves in order to circulate a fluid flow, which is typically from a pressurized

Steam flow is formed to lead past a turbine of the power plant. The injection of the cooling fluid serves to reduce the thermal energy of the fluid flow, that is to say in particular to lower its temperature. The temperature of the fluid stream is typically in a range between 400 ° C. and 650 ° C. at a pressure of over 50 bar, typically of over 100 bar.

[05] In practice, the problem has arisen that the fluid flow can be laden with small particles. This can occur, for example, as a result of corrosion processes in

Pipelines of the power plant may be the case. As a result of the corrosion, individual particles become detached from the pipelines and are then introduced into the fluid flow with and finally into the valve device. Such particles have a highly abrasive effect in the valve device, so that the valve devices are destroyed comparatively quickly.

[06] It follows that in order to increase the service life of a respective

Valve device generally a construction must be produced which is more robust than the previous valve devices. The requirement for greater robustness led to the consideration of reducing the use of parts that could move relative to one another. In valve devices of the prior art, it is common to have a

To achieve regulation of the fluid flow by means of a specific configuration of the piston, which can be positioned in various positions relative to the sealing seat. Here, depending on the position of the piston in relation to the sealing seat, a different cross-sectional area, which is available to the fluid flow as a whole for passing through the sealing seat, is released. The movement of the piston is therefore used to regulate the amount of fluid flow through the valve device. This known solution has proven to be unsuitable in view of the high abrasive wear, since the piston, which is in particular equipped with a perforated cylinder, is the abrasive

Was not able to withstand stresses in tests.

With the abolition of the regulation option described, which was then dispensed with, it had turned out to be problematic to provide a satisfactory atomization of the injected cooling fluid for different amounts of the fluid flow. By means of the regulation option in the prior art,

Flow channels that are responsible for generating corresponding atomization flows a proportion of atomizing current can be specifically assigned so that the problem did not occur in the same way.

task

[08] Therefore, the task arose of providing a robust valve device by means of which reliable atomization of the cooling fluid is possible for widely differing amounts of fluid flow.

solution

[09] The underlying object is achieved according to the invention by means of a valve device with the features of claim 1. Advantageous refinements result from subclaims 2 to 14.

The valve device according to the invention is characterized in that the flow element has a protruding into a flow area of the fluid flow,

has circumferential feed section, by means of which part of the fluid flow can be captured and can be directed specifically to the flow channels assigned to the feed section. In addition, an inner wall of the housing has a circumferential annular projection assigned to the feed section and extending radially in the direction of the central axis, by means of which at least part of the fluid flow can be directed away from the inner wall of the housing in the direction of the feed section of the flow element.

In other words, the invention provides that the fluid flow is directed specifically to a feed section of the flow element, which over a plurality of

Has flow channels. These flow channels serve to accelerate the respective portion of the fluid flow (“atomization flow edge”) that is fed to the feed section and to convert it into the atomization flows. Using the

According to the invention, the geometry of the feed section is matched to the formation of the annular projection of the inner wall of the housing, the possibility is now created of the fluid flow to a reliably high proportion of the flow channels

Feed section so that the processed by means of the feed section

Atomization flow portion of the fluid flow is accelerated appreciably. The coordination of the geometries of the inner wall of the housing and the supply section of the

Flow elements also cause the feed section itself to be a

a sufficiently large atomization flow component is supplied when the total amount of fluid flow which flows through the valve device is comparatively low. Thus, it has been shown in tests that the atomization flow component caused by the Flow channels of the supply section is passed, regardless of the amount of the total fluid flow can be kept above 20% of the fluid flow.

The atomization flow component is advantageously greater with a relatively low amount of fluid flow than with a larger amount of fluid flow. Ideally, an absolute mass flow of the atomizing flow component is at least essentially constant regardless of the amount of the total fluid flow. This ensures that the fluid flow is accelerated sufficiently strongly in any case by means of the flow channels of the supply section and consequently provides the desired atomizing effect for the injected cooling fluid.

In a particularly advantageous embodiment of the invention

Valve device, the annular projection - viewed in the direction of flow of the fluid flow - is designed to be curved or “swung”. This configuration has the advantage that the fluid flow, which flows along the inner wall of the housing at least substantially parallel to the central axis of the housing, when it hits the

The ring projection does not suddenly strike a discontinuously protruding wall, but is received as a result of the continuously curved design of the ring projection and is directed to the feed section while maintaining an at least substantially directed flow characteristic. In particular, the formation of

Recirculation areas and dead water areas are reduced. A corresponding configuration results from the exemplary embodiment listed below.

[13] Basically regardless of the design of the described

Ring projection, nevertheless in a particularly advantageous manner in combination with the same, the feed section of the flow element is formed equally curved, the curvature of the feed section preferably the curvature of the

Ring projection continues. In particular, the feed section can be locally designed, so to speak, in the shape of a shell, so that it captures the atomization flow portion of the fluid flow directed towards it. Advantageously, the curvature in the area of the feed section - viewed radially in relation to the central axis of the housing - gradually increases from the outside to the inside. The only option for the captured

The atomization flow component to leave the feed section in the flow direction is then provided by the flow channels through which the fluid flow is pressed. In this case, the described acceleration takes place as desired, so that the atomization flow component leaves the flow channels of the flow element as a plurality of atomization flows. The acceleration effect of the flow channels can in particular lead to that a flow velocity of the fluid flow is accelerated locally by several 100 m / s.

[14] The valve device according to the invention is further developed

Flow element together with the housing in such a way that the fluid flow the

Flow element must flow through the valve device in the course of its flow. In other words, the flow element adjoins the housing so that there is no possibility for the fluid flow to leave the valve device without flowing through the flow element. In this way it is avoided that the fluid flow “evades” the flow resistances represented by the flow channels.

Furthermore, such a configuration of the valve device according to the invention is advantageous, in which the annular projection of the housing and the supply section of the

Do not connect flow elements directly to one another, but instead

End edges thereof are spaced apart from one another. In this way, the end edge of the annular projection and the end edge of the feed section together delimit a flow gap through which a part of the fluid flow passes

("NebenstromanteN") can flow past the supply section. Advantageously, the bypass flow component which is not fed to the feed section can then flow through further flow channels of the flow element. By means of the mentioned

Execution creates the possibility of temporarily dividing the fluid flow by means of the flow element into two parts, namely a first part which is directed to the feed section (atomization flow part) and a second part which is directed to the

Feed section flows past (secondary flow portion).

Due to the inventive flow-directing design of the

Inner wall of the housing in combination with that according to the invention

The flow-catching configuration of the feed section is the latter primarily

to a certain extent primarily charged with the fluid flow, so that in principle - and in particular largely independently of an amount of the fluid flow - a

there is a sufficiently pronounced atomization flow component, by means of which, according to the above explanation, the desired atomization of the cooling fluid is subsequently possible. The remaining flow channels of the flow element that are not assigned to the feed section are additionally available for the fluid flow to pass through the flow element.

[17] The diameters of the flow channels of the feed section are advantageously larger, in particular at least twice as large, as the diameters of the flow channels that are not assigned to the feed section. The latter can in particular such be designed that they act as a throttle stage for the fluid flow and in this way contribute to a desired pressure and temperature reduction of the fluid flow.

[18] The flow channels of the flow element which are assigned to the feed section are advantageously designed such that - viewed in the flow direction of the fluid flow - they extend obliquely in the direction of the central axis of the housing. In such a configuration, the flow channels act in such a way that they each impress on the atomization flows generated by their action at least one - in relation to the central axis of the housing - radial directional component. Ideally, the flow channels are aligned at an angle of approximately 45 ° with respect to the central axis. The inclined configuration of the flow channels of the feed section helps to direct the generated atomization flows in a targeted manner “under” the injection device so that the cooling fluid injected by means of the injection device is injected directly into the atomization flows. Preferably, the flow element is relative to the

Injection device arranged that the flow channels of the feed section the

Surround the injection device circumferentially and, due to its inclined configuration, direct the fluid flow circumferentially radially inward under the injection device. A corresponding configuration results from the exemplary embodiment below.

[19] The valve device according to the invention further comprises that

Flow element - viewed in the direction of flow of the fluid flow - circumferentially adjoining the feed section. The cantilever section can in particular adjoin a radially outer end of the feed section and extend from there. The cantilever section, together with the inner wall of the housing, delimits an annular space into which the secondary flow portion of the fluid flow can flow. The cantilever section has a multiplicity of flow channels through which the secondary flow component can then pass, starting from the annular space, in the direction of a central space of the flow element. A feed of a portion of the fluid flow to the annular space can in particular take place through a flow gap described above, which is between mutually associated end edges of the annular projection of the

Housing and the supply section of the flow element is present.

[20] The cantilever section is advantageously designed in such a way that it cooperates tightly with the housing at its end remote from the feed section, that is to say, in particular, is connected to the inner wall of the housing in a sealing manner. In this way it is ensured that the secondary flow portion of the fluid flow located in the annular space can leave the annular space exclusively through the flow channels of the cantilever section. A flow around the flow element is therefore prevented. [21] For the purpose of uniform loading of all flow channels of the cantilever section, it can also be advantageous if the annular space delimited between the housing and the cantilever section tapers when viewed in the direction of flow of the fluid flow. This tapering can be achieved in particular in that the cantilever section is designed in the form of a truncated cone section which widens conically starting from the feed section.

In a further advantageous embodiment of the invention

Valve device, the flow element is arranged downstream of the injection device. The flow element preferably adjoins a lower end of the injection device. It is particularly advantageous if the feed section of the flow element surrounds a lower end of the injection device all the way around, viewed in the direction of flow of the fluid flow. This has the advantage that the flow channels assigned to the feed section are as close as possible to the

Injection device are arranged so that the conversion of the atomization flow portion of the fluid flow effected by means of the flow channels into individual

Atomization flows as close as possible to the injection device. In this way it is achieved that the flow velocity of the atomizing streams in one

Injection area in which the cooling fluid mixes with the fluid flow is as large as possible. Accordingly, the atomizing effect of the atomizing streams is as great as possible in the desired manner.

Regardless of the configuration of the flow element, such a valve device can also be particularly advantageous in which the inlet connector is assigned a particularly rotationally symmetrical perforated cylinder which surrounds the piston circumferentially and has a large number of flow channels. The perforated cylinder serves to equalize the inflow of the fluid flow through the inlet nozzle, so that the inflow of the piston or the sealing seat is as uniform as possible. With regard to the most robust possible design of the valve device, this is advantageous, since an asymmetrical flow onto certain areas of the valve device is avoided and consequently a load on the material of the valve device is evened out.

In addition, it can be particularly advantageous if the flow channels of the

Valve device are formed countersunk regardless of their affiliation to individual components of the same. Here, a diameter of a respective flow channel is expanded in a funnel-shaped manner in a front end region, viewed in the direction of flow of the fluid flow. This configuration helps to at least partially provide inner lateral surfaces of the flow channels with a coating that has a resistance of the respective affected component increased against abrasive wear. In particular, it is conceivable to provide the individual components of the valve device with a chromium carbide coating.

Embodiments

[25] The invention is explained in more detail below using an exemplary embodiment that is illustrated in the figures. It shows:

1: A schematic cross section through an inventive

Valve device and

2: A schematic detail of a flow element of the valve device according to FIG. 1. [26] An exemplary embodiment, which is shown in FIGS. 1 and 2, comprises a valve device 1 according to the invention. This comprises a housing 3 which is at least essentially rotationally symmetrical with respect to a central axis 2 is formed. An inlet nozzle 4 is connected to the housing 3, by means of which the valve device 1 can be supplied with a fluid flow 5. The fluid stream 5 first flows into an inlet space 34, within which an axially movable piston 6 is arranged. Said piston 6 serves to cooperate in a sealing manner with a sealing seat 7 assigned to it. The piston 6 can be moved between different positions relative to the sealing seat 7, and depending on the position of the piston 6, an amount of the fluid flow 5 which flows through the valve device 1 can be regulated. In the example shown, there is a in the entry space 34

Perforated cylinder 22 is arranged, which has a plurality of flow channels 23. The perforated cylinder 22 surrounds both the piston 6 and the sealing seat 7, so that it is only possible to pass through the sealing seat 7 after the flow channels 23 of the perforated cylinder 22 have flowed through. The perforated cylinder 22 acts to a certain extent as a throttle stage, which achieves an equalization of the flow to both the piston 6 and the sealing seat 7. After passing through the sealing seat 7, the fluid flow 5 reaches a central space 35 of the valve device 1, the central space 35 in the example shown being a

Throttle stage 28 is assigned. This comprises a plurality of flow channels 29 through which the fluid flow 5 must flow in the course of flowing through the valve device 1. The flow channels 29 cause a pressure reduction and a

Lowering the temperature of the fluid flow 5. Depending on the specification, the valve device 1 can be equipped with a plurality of throttle stages 28 in order to achieve a desired one

To achieve a reduction in pressure and temperature of the respective fluid flow 5.

[27] For the purpose of reducing thermal energy of the fluid flow 5, the valve device 1 further comprises an injection device 9, which is provided with a supply channel 24 for supplying a Cooling fluid 31 cooperates. The feed channel 24 adjoins a nozzle housing 25 of the injection device 9, within which an injection nozzle 36 is arranged. This is pressed against a nozzle seat 27 by means of a spring 26, so that the injection nozzle 36, together with the nozzle seat 27, cooperates in a sealing manner when it is in an otherwise force-free state. In order to trigger the injection nozzle 36, the injection device 9 is charged with the cooling fluid 31. Under the pressure of the latter, a spring force of the spring 26 is overcome, so that the injection nozzle 36 is pressed out of its nozzle seat 27. This releases a flow connection from the supply channel 24 to an interior space of the housing 3, whereupon the cooling fluid 31 is injected into the fluid flow 5. Due to a conically tapering design of the nozzle seat 27, the cooling fluid 31 is injected in a conical shape, as can be seen particularly well with reference to FIG.

[28] So that the cooling fluid 31 evaporates as quickly as possible and in this way the desired cooling of the fluid flow 5 is achieved, the cooling fluid 31 is atomized.

For this purpose, it is injected into atomization streams 12, which is supplied by a

Atomization flow portion 33 of the fluid flow 5 is formed. In order to generate the atomization flows 12, the valve device 1 comprises a flow element 8 which, in the example shown, is pot-shaped. The flow element 8 comprises an upper one

Feed section 13 and a lower cantilever section 19. In the example shown, the feed section 13 adjoins a lower end 37 of the injection nozzle 36 of the injection device 9, viewed in the flow direction of the cooling fluid 31, and extends in the radial direction relative to the central axis 2 of the housing 3 outward. In this way, the feed section 13 protrudes to a certain extent into a flow of the fluid flow 5. The cantilever section 19 adjoins a radially outer end of the feed section 13 on the latter and, starting from the feed section 13, extends in a conically widening manner in the flow direction of the fluid flow 5.

According to the invention, the feed section 13 of the flow element 8 interacts with an annular projection 15 formed on an inner wall 14 of the housing 3.

This is characterized in that it protrudes radially with respect to the central axis 2 inward on the inner wall 14 and in this way has a deflecting effect on the

Fluid flow 5 exerts. In particular, a radially inwardly directed directional component is impressed on the fluid flow 5 by means of the annular projection 15. The annular projection 15 is continuously curved, viewed in the direction of flow of the fluid flow 5, that is to say without a discontinuously projecting projection. What is achieved hereby is that the fluid flow 5 is deflected away from the inner wall 14 over a steering path, without the fluid flow 5 striking a discontinuously protruding baffle surface and thereby becoming a turbulent one Electricity is converted. In the example shown, the feed section 13 of the flow element 8 is designed to be curved in the same way, the feed section 13 continuing the curvature of the annular projection 15. This can be seen particularly well on the basis of the detail according to FIG. 2. A curvature profile is based on FIG

Inner wall 14 up to a radially inner end of the feed section 13 in a steadily increasing manner, with the feed section 13, viewed in cross section, being designed as it were bowl-shaped and capturing the fluid flow 5 in this way. The feed section 13 is connected directly to the injection device 9 at its radially inner end, with the flowing past

Atomization flow portion 33 of the fluid flow 5 at the flow element 8 between the feed section 13 and the injection device 9 is not possible.

[30] In the example shown, the feed section 13 interacts with a plurality of flow channels 10 which allow a flow through the flow element 8. The flow channels 10 intentionally narrow a flow cross-section for the atomization flow portion 33 of the fluid flow 5, so that the atomization flow portion 33 is greatly accelerated in the course of the flow through the flow channels 10. As a result, by means of the plurality of flow channels 10, a plurality of atomization streams 12 is generated, the flow rate of which is compared to a flow rate of the fluid stream 5 on this side

Flow element 8 is greatly increased. The flow channels 10 are oriented obliquely inward relative to the central axis 2 of the housing 3, so that the

Atomization streams 12 receive a radial directional component which is directed towards the central axis 2. In this way, the atomization streams 12 are guided directly below the injection device 9. As a result, the cooling fluid 31 is injected directly into the atomization streams 12, in which there is a high flow velocity. What is achieved hereby is that the cooling fluid 31 is very finely atomized, as a result of which very rapid evaporation of the cooling fluid 31 is achieved.

The annular projection 15 and the feed section 13 of the flow element 8 are arranged at a distance from one another, with mutually associated end edges 16, 17 of the annular projection 15 or the feed section 13 jointly delimiting a flow gap 18. A portion of the fluid flow 5 can be conducted past the feed section 13 through this flow gap 18. This portion is referred to here as the secondary flow portion 32. The secondary flow portion 32 flows into an annular space 20, which of the

Housing 3 and the cantilever portion 19 of the flow element 8 is limited. Of the

The cantilever section 19 is frustoconical here, with an in Has a conically widening cross-section when viewed in the direction of flow of the fluid flow 5. At an end facing away from the supply section 13, the cantilever section 19 adjoins the inner wall 14 of the housing 3 in a sealing manner at a contact point 30 (or a circumferential contact ring). As a result, the secondary flow portion 32 of the fluid flow 5 can flow exclusively through flow channels 11 of the flow element 8 which are assigned to the cantilever section 19. Here, the bypass flow portion 32 is in the radial direction based on the central axis 2 of the housing 3 in a central space 21 of the

Flow element 8 supplied.

The interaction of the annular projection 15 and the protruding feed section 13 has the effect that the atomization flow component 33, which is fed to the central space 21 by means of the feed section 13, is relatively independent of an amount of the total

Fluid flow 5 remains the same in relation to the secondary flow portion 32. In particular, it is achieved that even with a comparatively small amount of the fluid flow 5, the atomizing flows 12 exert a sufficient atomizing effect on the cooling fluid 31 so that the latter is finely atomized and consequently evaporated quickly. The valve device 1 according to the invention thus achieves the goal of achieving a fine atomization of the cooling fluid 31 without having to adjust the flow element 8. In particular, it is possible to dispense with providing parts that are movable relative to one another, by means of which an allocation of flow components of the fluid flow to specific flow channels is forced in order to achieve sufficient acceleration of the fluid flow, including the resulting fine atomization of cooling fluid, regardless of the amount of the fluid flow. The inventive

Without such parts that can move relative to one another, valve device 1 is significantly more robust than known valve devices 1 which use such mechanisms.

In order to further improve the robustness of the valve device 1 with respect to abrasive wear, the valve device 1 in the example shown is designed to be coated. In particular, all surfaces that interact directly with the fluid flow 5 are provided with a chromium carbide coating. For this purpose, all flow channels 10, 11, 23, 29 valve device 1 are countersunk in a particularly advantageous manner, with a front inflow area of a respective flow channel widened in a funnel shape when viewed in the flow direction of the fluid flow 5. This configuration of the flow channels 10, 11, 23, 29 has proven to be particularly advantageous for coating inner lateral surfaces of the flow channels 10, 11, 23, 29 with a respective coating. List of reference symbols

1 valve device

2 central axis

3 housing

4 inlet nozzles

5 fluid flow

6 pistons

7 tight fit

8 flow element 9 injection device

10 flow channel 11 flow channel 12 atomization flow 13 feed section 14 inner wall

15 ring projection

16 end edge

17 end edge

18 flow gap 19 cantilever section

20 annulus

21 Middle room

22 perforated cylinders

23 flow channel 24 supply channel

25 nozzle housings

26 spring

27 nozzle seat 28 throttle level

29 flow channel

30 contact point

31 cooling fluid

32 Bypass flow

33 Part of atomization flow

34 Entry room

35 Middle room

36 injector

37 end

Claims

1. Valve device (1), in particular in the form of a control valve for power plants, comprising

a housing (3) extending along a central axis (2), an inlet connection (4) for introducing a fluid flow (5) into the

Housing (3),

a movable piston (6) and a piston (6)

assigned sealing seat (7),

a rotationally symmetrical one arranged in the housing (3)

Flow element (8) for treating the fluid flow (5) and an injection device (9) for injecting a cooling fluid (31), the fluid flow (5) being adjustable by means of the piston (6) in cooperation with the sealing seat (7),

wherein the flow element (8) has a plurality of flow channels (10) through which at least a part of the fluid flow (5) can be guided, accelerated in the course of this and in this way locally in

Atomization streams (12) can be transferred,

wherein the flow element (8) is arranged relative to the injection device (9) in such a way that the cooling fluid can be injected into the atomization flows (12),

characterized in that

the flow element (8) has a circumferential feed section (13) protruding into a flow area of the fluid flow (5), by means of which part of the fluid flow (5) can be caught and flow channels (10) assigned to the feed section (13) can be fed,

wherein an inner wall (14) of the housing (3) has a peripheral annular projection (15) assigned to the feed section (13) and extending radially in the direction of the central axis (2), by means of which at least part of the fluid flow (5) in the direction of the Feed section (13) of the

Flow element (8) is steerable.

2. Valve device (1) according to claim 1, characterized in that the annular projection (15) - viewed in the direction of flow of the fluid flow (5) - is curved, with the feed section (13) of the flow element (8) preferably having a curvature of the annular projection ( 15) is designed to be continued.

3. Valve device (1) according to claim 1 or 2, characterized in that the flow element (8) cooperates with the housing (3) in such a way that the fluid flow (5) as it flows through the valve device (1) the flow element (8) must flow through.

4. Valve device (1) according to one of claims 1 to 3, characterized

characterized in that an end edge (16) of the annular projection (15) and an associated end edge (17) of the feed section (13) are arranged at a distance from one another, so that they jointly delimit a flow gap (18) through which part of the fluid flow (5) can flow past the inner wall (14) of the housing (3) along the feed section (13).

5. Valve device (1) according to one of claims 1 to 4, characterized

characterized in that at least the supply section (13) of the

Flow channels (10) assigned to flow element (8) - in

The direction of flow of the fluid flow (5) viewed - to extend obliquely in the direction of the central axis (2) of the housing (3).

6. Valve device (1) according to one of claims 1 to 5, characterized

characterized in that the flow element (8) has a - in

The direction of flow of the fluid flow (5) viewed - has a cantilever section (19) which adjoins the feed section (13) and which, together with the inner wall (14) of the housing (3), delimits an annular space (20), the cantilever section (19) having a plurality of flow channels (11) through which the fluid flow (5), starting from the annular space, can pass into a central space (21) of the flow element (8).

7. Valve device (1) according to claim 6, characterized in that the

The flow element (8) is tightly connected to the inner wall (14) of the housing (3) at an end of the cantilever section (19) facing away from the feed section (13).

8. Valve device (1) according to claim 6 or 7, characterized in that the between the inner wall (14) of the housing (3) and the cantilever portion (19) of the flow element (8) limited annular space (20) - in

Viewed in the direction of flow of the fluid flow (5), it gradually tapers, with the cantilever section (19) preferably being designed in the form of a truncated cone section which, viewed in the flow direction of the fluid flow, widens conically starting from the feed section (13).

9. Valve device (1) according to one of claims 6 to 8, characterized

characterized in that flow channels (10) of the feed section (13) each have a larger diameter than flow channels (11) of the

Cantilever section (19), the diameter of a respective flow channel (10) of the feed section (13) preferably being at least twice as large as the diameter of a respective flow channel (11) of the cantilever section (19).

10. Valve device (1) according to one of claims 1 to 9, characterized

characterized in that the flow element (8) downstream of the

Injection device (9) is arranged, preferably directly adjoins a lower end of the injection device (9).

11. Valve device (1) according to claim 10, characterized in that the feed section (13) is assigned to the lower end of the injection device (9), in particular a lower end (37) of an injection nozzle (36) of the injection device (9), so that an injection of the cooling fluid (31) carried out by means of the injection device (9) can be injected directly into the atomization streams (12) generated by means of the flow channels (10) of the feed section (13).

12. Valve device (1) according to one of claims 1 to 11, characterized

characterized in that the flow channels (10) are arranged in a radially inner edge region of the feed section (13).

13. Valve device (1) according to one of claims 1 to 12, characterized by a rotationally symmetrical one assigned to the inlet connection piece (4)

Perforated cylinder (22) which surrounds the piston (6) and has a plurality of flow channels (23), the fluid stream (5) preferably having to flow through the perforated cylinder (22) to flow through the valve device (1).

14. Valve device (1) according to one of claims 1 to 13, characterized in that at least one flow channel (10, 11, 23, 29), preferably all of the flow channels (10, 11, 23, 29), are countersunk, preferably in their inflow areas.