Regulating valve with integrated purge function

A valve includes a valve body provided with a plug, connected to an actuation system, an upstream duct, a downstream duct, and a purge duct provided with a shutter. The plug is movable in rotation about a longitudinal axis in the valve body, so that the rotation of the plug according to a first angular sector defines a flow between the upstream duct and the downstream duct, the rotation of the plug according to a second angular sector separate from the first angular sector shuts off the connection between the upstream duct and the downstream duct, and the rotation of the plug according to a third angular sector included in the second angular sector actuates the shutter so as to allow a flow from the upstream duct to the purge duct.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase entry under 35 U.S.C. § 371 of International Application No. PCT/FR2019/050666, filed on Mar. 22, 2019, which claims priority to French Patent Application No. 1852824, filed on Mar. 30, 2018.

FIELD OF THE INVENTION

The present disclosure relates to control valves used in particular for the regulation of the flow rate of a cryogenic fluid of a spacecraft.

STATE OF THE PRIOR ART

The systems for regulating the flow rate of cryogenic propellants used in spacecrafts must allow performing flow rate regulation and purge functions.

These functions are commonly performed by distinct devices. A plug valve performs the flow rate regulation function, while a purge valve performs the purge function. However, such a configuration requires the use of multiple distinct pieces of equipment, which leads to a complexification of the structure (which then comprises in particular two actuation systems and two architectures of associated valve and body), as well as an increase in the associated mass, space requirement and costs.

The present disclosure thus aims to at least partially respond to these issues.

U.S. Pat. No. 3,770,016 A discloses a ball valve provided with a purge duct and suitable for water. Document US 2015/0129788 A1 discloses a ball valve suitable for cold or cryogenic fluids.

PRESENTATION OF THE INVENTION

The present disclosure relates to a valve for controlling the flow rate of a cryogenic fluid in a duct, comprising:a valve body provided with a plug connected to an actuation system,an upstream duct,a downstream duct,a purge duct provided with a shutter,
the upstream duct and the downstream duct opening into the valve body,
the purge duct being connected to the upstream duct, and the shutter being configured so as to be, by default, in a shut-off position of the purge duct,
the plug being movable in rotation along a longitudinal axis in the valve body, so that:the rotation of the plug according to a first angular sector defines a flow between the upstream duct and the downstream duct via the valve body,the rotation of the plug according to a second angular sector separate from the first angular sector shuts off the connection between the upstream duct and the downstream duct (or the internal volume of the valve body),the rotation of the plug according to a third angular sector included in the second angular sector actuates the shutter so as to allow a flow from the upstream duct to the purge duct.

According to one example, the plug is configured such that the flow between the upstream duct and the downstream duct via the valve body regulated by the rotation of the plug according to the first angular sector has pressure drops as a function of the rotation of the plug.

According to one example, the plug has a lug arranged on an outer surface of the plug, the lug being configured, when the plug is driven in rotation in the third angular sector, to come into contact and cause an actuation of the shutter so as to allow a flow from the upstream duct to the purge duct.

According to one example, the plug has an opening whose section increases from a first end to a second end, said opening being arranged about the axis of rotation of the plug.

The present disclosure also relates to a spacecraft comprising such a valve.

In all of the figures, the identical elements are identified by common reference numerals.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

A valve is described hereinafter according to one aspect of the invention with reference to the figures.

FIG. 1represents a view of a valve according to one aspect of the invention,FIG. 2represents a sectional view thereof, andFIG. 3is a detailed sectional view of a specific area of the valve.

The valve1comprises a valve body10in which a plug20is mounted, and to which an upstream duct30, a downstream duct40, a purge duct50, and a shutter55are connected.

The designations “upstream duct” and “downstream duct” are used depending on the operation envisaged for the valve1. The upstream duct30is intended to be connected to a fluid supply source (for example a cryogenic propellant) such as a tank or a turbopump, and the downstream duct40is intended to be connected to a propulsion member of a spacecraft, such as a gas generator.

The upstream duct30and the downstream duct40are thus fluidly connected to an internal volume of the valve body10.

The plug20is mounted in the internal volume of the valve body10, and fulfills a function of selective shut-off of the fluid communication between the upstream duct30and the downstream duct40.

The plug20thus typically has a generally cylindrical shape of revolution about an axis of rotation X-X. It has a through-opening21arranged on its wall, the opening21being adapted to be able to be aligned with the portion of the upstream duct30opening into the internal volume of the valve body10. This opening21arranged in the plug20has a variable section as a function of the angular sector about the axis X-X, typically an opening section increasing from a first end to a second end, so that a rotation of the plug20within the valve body10about the axis X-X allows controlling the fluid flow rate which can pass from the upstream duct30to the internal volume of the valve body10, and therefore more generally from the upstream duct30to the downstream duct40.

Thus, the rotation of the plug20about the axis X-X via an actuation system (not represented) allows controlling the pressure drops generated by the plug20, and therefore the fluid flow rate passing from the upstream duct30to the downstream duct40. Note however that the opening21extends over an angular sector less than 360°, the remaining angular sector thus allows making a shut-off of the connection between the internal volume of the valve body10and the upstream duct30. The plug20can be connected to the actuation system (not represented) via the end29of the plug20which is opposite to the downstream duct40.

The valve1as proposed exploits this angular sector by positioning therein a lug25extending from the outer surface of the plug20, typically positioned so as to be facing the purge duct50and thus allow actuating a shutter55of the purge duct50as described below.

The purge duct50is formed so as to allow connecting the upstream duct30to a purge line (not represented). The purge duct is thus fluidly connected to the upstream duct30, the connection being made upstream of the junction between the upstream duct30and the internal volume of the valve body10, and therefore upstream of the plug20. A shutter55is slidably mounted in the purge duct50, so as to selectively shut it off. This shutter55is associated with a return element56, typically a spring, ensuring a default holding of the shutter55in the shut-off position.

The shutter55has a rod whose end opens into the internal volume of the valve body10. This rod is positioned so as to be able to be actuated by the lug25formed on the plug20when the rotation of the plug20is made according to a defined angular sector. The lug25then exerts a pushing force on the shutter55to make it slide in the purge duct50while opposing the force exerted by the return element56, and thus allow a passage of fluid from the upstream duct30to the purge duct50.

When the plug20rotates such that the lug25is no longer in contact with the shutter55, the latter is brought back to the shut-off position due to the return element56.

The lug25typically has a central section from which a functional ramp of the lug25extends, such that the continuous rotation in the same direction of the plug20about the axis X-X brings the shutter55into contact with this functional ramp, then with its central section (corresponding to the maximum displacement). Such geometry allows regulating the movement of the shutter55and therefore the opening of the purge duct50.

Thus, the valve1as proposed allows, as a function of the angular position of the plug20, regulating the flow rate passing from the upstream duct30to the downstream duct40, shutting off the passage of the fluid from the upstream duct30to the downstream duct40, or performing a purge of the upstream duct30via the purge duct50.

These different configurations are thus represented inFIGS. 5 to 7. InFIGS. 3 and 5 to 7, in order not to overload the drawing, the various seals ensuring the sealing of the valve1, in particular when it shuts off the passage of the fluid from the upstream duct30to the downstream duct40, are not represented.

In order to illustrate the operation thereof, a diagram is represented inFIG. 8with different angular sectors to schematize the rotation of the plug20and the different configurations of the valve1.

A first angular sector A1is considered, which corresponds to an area of regulation of the flow rate passing from the upstream duct30to the downstream duct40via the plug20, and more specifically thanks to the scalable opening21made in the plug20, which corresponds to the configuration represented inFIG. 5.

A second angular sector A2separate from the first angular sector A1corresponds to the configuration in which the plug20shuts off the upstream duct30. The second angular sector A2and the first angular sector A1are represented as being separated by sealing areas E1and E2.

The sealing area E1defines a margin between the closed position of the valve1and its opening via the opening21of the plug.

The sealing area E2is for its part a non-functional area, which can form an abutment between the position corresponding to the valve1having a maximum or a minimum opening, and the position corresponding to the valve1closed and to the purge duct50open.

The cumulative amplitude of the angular sectors A2, E1and E2contributes to the good mechanical strength of the plug20, and must therefore be sufficient to ensure good rigidity of the plug20.

Within the second angular sector A2, a first sub-sector A21and a second sub-sector A22are distinguished. The first sub-sector A21corresponds to the configuration in which the plug20shuts off the upstream duct30, and the lug25is not in contact with the shutter55(the purge duct50is then shut off), which corresponds to the configuration represented inFIG. 6. The second sub-sector A22corresponds to the configuration in which the plug20shuts off the upstream duct30, and the lug25is in contact with the shutter55in order to control the opening of the purge duct50, which corresponds to the configuration represented inFIG. 7, that is to say a purge action while maintaining the passage from the upstream duct30to the downstream duct40shut off.

Therefore to summarize, the valve1as proposed allows accumulating flow rate regulation and purge functions within a single equipment, by exploiting an angular range of rotation of the plug20which remains unexploited in the existing systems.

It will also be noted that the actuation in rotation of the plug20as described above, and therefore the control of the valve1, can be performed by a single actuation system.

The valve1as proposed or more specifically the valve body10is typically made by additive manufacturing.