Valve, fluid transfer device and pump comprising such a valve

Abstract

The invention relates to a fluid inlet valve (1), for example for the transfer of a cryogenic fluid such as liquid hydrogen, comprising a valve body extending in a longitudinal direction (A) and having a flared end (2) for sealing with a valve seat (3), characterized in that the flared end (2) comprises at least one channel (4) passing through the flared end (2) and opening on either side of the flared end at two ends offset respectively in the longitudinal direction. Illustration: Fig. 1

Description

Title of the invention: Valve, fluid transfer device and pump comprising such a valve

[0001] The invention relates to a valve, a fluid transfer device and a pump comprising such a valve.

[0002] The invention relates more particularly to a fluid inlet valve, for example for the transfer of a cryogenic fluid such as liquid hydrogen, comprising a valve body extending in a longitudinal direction and provided with a flared end intended to cooperate in a hermetic manner with a valve seat.

[0003] The invention can be applied to a controlled valve, i.e., actuated by a controlled actuating member, or a free valve (i.e., whose openings and closings are caused by the pressure differential between its upstream / downstream sides).

[0004] Conventionally, a fluidic valve is movable between two positions: open and closed. In the closed position, the valve must provide a good seal. In the open, or flowing, position, the valve must have a minimal influence on the pressure drop of the fluid allowed to pass through.

[0005] In the context of pressurization machines (compressors and / or pumps) operating at high pressures, up to several hundred bar, a valve is commonly used to admit fluid into the compression chamber. This is called an inlet valve. A fairly common design is the conical valve, which offers a good contact surface and good pressure resistance.

[0006] In the context of cryogenic pump development, the performance of the inlet valve in the forward direction is particularly critical. Indeed, an excessive pressure drop across the valve can potentially lead to a sudden evaporation, or "flash," phenomenon, which occurs when the pressure reaches the fluid's saturation pressure. This can result in a decrease in mass efficiency because less fluid is then transferred.

[0007] This risk of "flash" is particularly significant at the point of greatest narrowing in the valve's design (at a "neck"-shaped portion). Indeed, at this point, the fluid velocity approaches the critical regime and the pressure drops below the saturation pressure. Proper sizing of the neck and valve lift generally reduces this risk.

[0008] A significant depression can develop in the diverging conical zone between the valve and its seat. This can reduce the valve's lift and therefore its lift towards its opening position. This improper opening degrades the valve's discharge coefficient.

[0009] The flashing phenomenon can also occur during the filling of the intake chamber, downstream of the valve. Indeed, a large angular jet can cause poor filling, leading to the formation of vortex-shaped recirculation pockets in the center of which a strong pressure drop of several tens to several hundred millibars can be observed. Consequently, significant flashing is likely to occur, thus degrading the pump's performance, particularly its mass efficiency.

[0010] One object of the present invention is to overcome all or part of the disadvantages of the prior art noted above.

[0011] To this end, the valve according to the invention, which also conforms to the generic definition given in the preamble above, is essentially characterized in that the flared end comprises at least one channel passing through the flared end and opening on either side of the flared end at the level of two ends offset along the longitudinal direction.

[0012] This configuration ensures communication between the flared (conical) portion of the valve and the downstream volume, which reduces or eliminates the localized depression between the valve and the seat. This improves the valve lift and thus increases its discharge coefficient.

[0013] Furthermore, embodiments of the invention may include one or more of the following features: - the flared end is truncated cone-shaped, - at least one channel is straight and parallel to the longitudinal direction. - at least one channel is straight and inclined with respect to the longitudinal direction tudinal with an angle preferably less than or equal to 15 degrees, - at least one channel has a constant cylindrical cross-section along the longitudinal direction - at least one channel has a cylindrical cross-section that diverges along the longitudinal direction, - The valve comprises several channels, - the valve comprises several channels arranged angularly around an axis central longitudinal of the valve body.

[0014] The invention also relates to a fluid transfer device comprising a sealed volume delimited by at least one wall and provided with a transfer orifice housing a valve according to any one of the characteristics above or below, the orifice defining a seat for the valve, the valve being movably mounted in the orifice between a first sealed closed position of the orifice and a second opening position of the orifice, in the first position, the cooperation of the valve with the seat prevents the entry of fluid or the exit of fluid from the volume through the channel.

[0015] The invention also relates to a pump for fluid, for example for cryogenic fluid, comprising such a transfer device, the sealed volume being a compression chamber comprising an inlet compression element of the pump, for example a movable piston.

[0016] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0017] Other features and advantages will become apparent from the following description, given with reference to the figures in which: Brief description of the figures

[0018] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0019] [Fig-1] is a schematic, partial, schematic cross-sectional view of an example of a detail of a pump comprising a transfer device with a valve according to the invention,

[0020] [Fig.2] is a schematic and partial longitudinal cross-sectional view of a detail of a valve in its seat according to a first possible embodiment,

[0021] [Fig.3] is a schematic and partial longitudinal cross-sectional view of a detail of a valve according to a second possible embodiment,

[0022] [Fig.4] is a schematic and partial perspective view of a valve according to a third possible embodiment,

[0023] [Fig.5] is a schematic and partial perspective view of a valve according to a fourth possible embodiment. Detailed description

[0024] In all figures, the same references refer to the same elements.

[0025] In this detailed description, the following achievements are examples. The fact that the description refers to one or more embodiments does not mean that the features apply only to a single embodiment. Simple features from different embodiments can also be combined and / or interchanged to provide other embodiments.

[0026] The illustrated valve examples 1 each include a valve body extending along a longitudinal direction A and having a flared end 2 intended to cooperate tightly with a valve seat 3.

[0027] According to an advantageous feature, the flared end 2 comprises at least one channel 4 or drilling (and preferably several) through the flared end 2 and opening out on either side of the flared end at the level of two ends offset respectively along the longitudinal direction A.

[0028] This presence of channel 4 (channels) allows the fluid flow to be uniform at the inlet when opening) and avoiding or minimizing large annular fluid jets responsible for recirculation pockets.

[0029] Known valves comparatively generate more unidirectional axisymmetric fluid jets which cause poor fluid transfer (recirculation pockets causing excessive flashing).

[0030] Fig. 1 illustrates an example of a fluid transfer device comprising such a valve 1. The transfer device in this example is a pump comprising a sealed volume (compression chamber) delimited by at least one wall 5 and provided with a transfer port 6 (inlet) housing a valve 1 as previously mentioned.

[0031] The orifice 6 defines a seat for the valve 1 (flared portion receiving the flared end of the valve 1). The valve 1 is mounted movable in the orifice 6 (for example in translation) between a first position of tight closure of the orifice 6 and a second position of opening of the orifice 6. In the first position, the cooperation of the valve with the seat prevents the entry of fluid or the exit of fluid from the volume 5 through the channel 4 (or channels).

[0032] When the orifice is opened (passage of the soup 1 into the second position), part of the fluid flow admitted to enter the volume 5 passes through the channel or channels 4.

[0033] This fraction of fluid flow that passes along and through the flared end 2 reduces the tendency of the fluid flow to adhere to the wall of the flared end 2 of the valve. During opening, the fluid flow entering volume 5 is better distributed towards and along the wall of the seat 6. The harmful disturbances that create flashing are reduced.

[0034] The valve 1 may have several channels 4 which may be straight and parallel to the longitudinal direction A of the valve 1 (see [Fig. 2]) or slightly inclined with respect to the longitudinal direction A of the valve 1 (see [Fig. 3]). For example, the channels 4 may be inclined towards the central axis of the body of the valve 1.

[0035] This longitudinal direction A can coincide with the direction of movement of valve 1.

[0036] The channels 4 can be of circular cross-section of constant diameter (see [Fig.2]) and / or divergent (see [Fig.3], for example diverging in the direction of the intake chamber).

[0037] As can be seen in [Fig.2] and [Fig.3] several channels can be distributed circularly at equal distances around the central longitudinal axis of the valve, for example near the periphery of the diverging end.

[0038] As illustrated in [Fig. 4], two sets of channels 4 can be distributed circularly at different distances around the central longitudinal axis of the valve. These two sets of channels 4 can be located on different radii around the central longitudinal axis.

[0039] The number and / or size and / or distribution of the 4 channels can be adapted and several 4 channel configurations can be combined.

[0040] The cross-section (in diameter) of the channels 4 can be between 0.1 mm and 2.5 mm depending on the dimensions of the valve 1 to represent, for example, from 0.5% to 12.5% ​​of the largest diameter of the valve 2.

[0041] This valve 1 and the corresponding transfer or inlet device can be used for a cryogenic pump, a liquid pump (cryogenic or otherwise), a multiphase pump, a gas pump or compressor. This can also be applied to an inlet or outlet valve system in a fluid line.

[0042] The invention can be applied in a particular way in applications where the fluid is hydrogen, helium, natural gas or any other fluid or mixture.

Claims

Demands

1. Fluid inlet valve (1), for example for the transfer of a cryogenic fluid such as liquid hydrogen, comprising a valve body extending in a longitudinal direction (A) and having a flared end (2) for cooperating hermetically with a valve seat (3), the flared end (2) comprising at least one channel (4) passing through the flared end (2) and opening out on either side of the flared end at two ends offset respectively in the longitudinal direction, characterized in that the at least one channel (4) has a cylindrical cross-section diverging in the longitudinal direction (A).

2. Valve (1) according to claim 1, characterized in that the flared end (2) is frustoconical in shape.

3. Valve (1) according to claim 1 or 2, characterized in that at least one channel (4) is straight and parallel to the longitudinal direction.

4. Valve (1) according to any one of claims 1 to 3, characterized in that at least one channel (4) is straight and inclined with respect to the longitudinal direction (A) with an angle preferably less than or equal to 15 degrees.

5. Valve (1) according to any one of claims 1 to 4, characterized in that at least one channel (4) has a constant cylindrical cross-section along the longitudinal direction (A).

6. Valve (1) according to any one of claims 1 to 5, characterized in that it comprises several channels (4).

7. Valve (1) according to claim 6, characterized in that it comprises several channels (4) distributed angularly around a central longitudinal axis of the valve body.

8. Valve according to claim 7 characterized in that the valve comprises two sets of channels (4) distributed circularly at different distances around the central longitudinal axis of the valve.

9. A fluid transfer device comprising a sealed volume delimited by at least one wall (5) and having a transfer orifice (6) for a valve (1) according to any one of the preceding claims, the orifice (6) defining a seat for the valve (1), the valve (1) being movably mounted in the orifice (6) between a first sealed closed position of the orifice (6) and a second position opening of the orifice (6), in the first position, the cooperation of the valve with the seat prevents the entry of fluid or the exit of fluid from the volume (5) through the channel (4).

10. Pump for fluid, for example for cryogenic fluid, comprising a transfer device according to claim 9, the sealed volume being a compression chamber comprising an inlet compression element (7) of the pump, for example a movable piston (7).

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