Cooling valve for a rocket engine with cryogenic propellant and rocket engine equipped with said cooling valve

Abstract

To provide a cooling valve for a rocket engine with an improved cryogenic propellant, a rocket engine with a cryogenic propellant comprising the valve, and a spacecraft comprising the rocket engine.SOLUTION: A cooling valve 10 for a rocket engine includes a casing 12 having a passage 14 extending along an axial direction X, and a valve 16 that is housed in the casing 12 and is movable with respect to the casing 12 along the axial direction X. In the cooling valve 10 for a rocket engine, the valve 16 comprises a stem 16B extending along the axial direction X, and a head portion that is connected to the stem 16B to closely close or open the passage 14. The stem 16B is coupled to the casing 12 by at least one binary metal element 18, 18' which is configured to deform along the axial direction X as a function of the ambient temperature in the passage 14.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a cooling valve for a rocket engine with cryogenic propellant, a rocket engine with cryogenic propellant including such a valve, and a spacecraft equipped with such a rocket engine.

[0002] The term "cooling down" refers to the operation of generally cooling all or part of a rocket engine turbopump or other components to a predetermined temperature so that the turbopump of the rocket engine is under required operating conditions. In particular, a propellant delivery pump for a rocket engine is cooled before the turbopump is started, i.e., when the turbopump is stopped.

[0003] The term "spacecraft" means any vessel intended to be sent into space, including but not limited to a single stage of a space launcher, a space shuttle with a single stage, a satellite, or the like. [Background technology]

[0004] Known cooling systems for rocket engines generally comprise valves controlled by electrical or pneumatic systems. Such valves and associated control devices are generally complex. A first simplification of these control devices consists of controlling the closing / opening of the valve as a function of a predetermined time period, rather than the effective temperature inside the fluid circuit, in order to avoid a feedback loop. However, effective cooling within the fluid circuit is not optimized. In particular, the amount of propellant consumed during the cooling is substantial to ensure cooling to the required temperature under all circumstances. Therefore, a need exists in this field. Summary of the Invention

[0005] One embodiment relates to a cooling valve for a rocket engine, the cooling valve comprising a casing having a passageway extending along an axial direction and a valve housed within the casing and movable relative to the casing along the axial direction, the valve comprising a stem extending along the axial direction and a head portion that closes or opens the passageway connected to the stem, the stem being coupled to the casing by at least one bimetallic element configured to deform along the axial direction as a function of ambient temperature within the passageway.

[0006] In the following, unless otherwise specified, "ambient temperature" is understood to mean the ambient temperature within the passageway, and in the following, unless otherwise specified, "bimetal element" is understood to mean at least one bimetal element.

[0007] The valve head is configured to cooperate with a seat provided in the wall of the passageway such that when the head abuts against the seat the passageway is closed (and thus the valve is closed), and conversely, when the head is away from the seat the passageway is open (and thus the valve is open).

[0008] The bimetallic element can deform continuously as a function of ambient temperature variations, or discontinuously with a threshold effect. The bimetallic element can amplify the movement resulting from thermal expansion, which is useful for opening and closing a valve as a function of ambient temperature.

[0009] It will be appreciated that the bimetallic element cooperates with the casing on the one hand and with the stem on the other hand, and by deforming it in an axial direction it displaces the stem and thus the entire valve in an axial direction, so that the head moves away from or towards the seat so as to open or close the valve.

[0010] The valve may be configured to close when the ambient temperature is below a predetermined temperature, or alternatively, to fully or partially open when the ambient temperature is above a predetermined temperature.

[0011] During a cooling operation, for example, a coolant is circulated in a fluid circuit extending through or near the part or parts to be cooled (which is generally warmer than the coolant), and this cooling circuit includes at least one valve according to the present disclosure, for example, in or downstream of the part to be cooled. The coolant is generally colder than the part to be cooled. As long as the walls of the part to be cooled are not at the same temperature as the coolant, the valve remains open or partially open, causing the part to heat the coolant. When the walls of the part to be cooled reach a predetermined temperature, for example, a temperature ±10% of the initial temperature of the coolant, the bimetallic element deforms axially to close the passage. Once the walls of the part to be cooled have reached the desired temperature, there is no longer any need for coolant flow. Therefore, the valve is closed.

[0012] In some embodiments, the stem is connected to the casing by only two separate bimetallic elements.

[0013] In other words, the valve may comprise exactly two bimetallic elements, which in this example may function on the one hand to displace the stem axially and on the other hand to guide the stem axially. The above arrangement is simple and robust, guarantees good reliability and is economical in terms of costs.

[0014] In some embodiments, the stem has two axially opposed ends, each connected to a single bimetallic element.

[0015] For example, the ends may extend from one end up to 30% of the total length of the rod. By connecting each end to a bimetallic element, perfect retention and guidance of the stem along the axial direction is ensured, which contributes to the reliability of the valve and its proper operation in a mechanical environment that may be destructive, for example, by vibration.

[0016] In some embodiments, the valve comprises at least one sleeve connected to the casing, the sleeve extending axially within the passage and axially slidably housing a stem, the stem being connected to the casing by a single bimetallic element.

[0017] In the following, "sleeve" is understood to mean at least one sleeve, unless otherwise specified.

[0018] In this example, the single bimetallic element can only serve to displace the stem axially, while the sleeve can only be used to guide the stem axially, thereby freeing up the bimetallic element and ensuring better control of the stem's axial position.

[0019] In some embodiments, the valve comprises two sleeves, and the stem has two axially opposed ends, each end engaged with one sleeve.

[0020] By engaging each end with a sleeve, the stem can be completely held and guided along the axial direction, contributing to the reliability of the valve.

[0021] In some embodiments, at least one bi-metallic element has a perforated annular or generally rectangular shape when viewed axially.

[0022] "General shape" is understood as the shape considered as a whole, without necessarily paying attention to slight variations in angles and edges. The above shape is particularly efficient and robust for displacing the stem along the axial direction while leaving sufficient openings for the passage of coolant between the casing and the stem.

[0023] In some embodiments, at least one bimetallic element is configured to deform along an axial direction to close the passageway when exposed to a predetermined ambient temperature between 10°K (10 degrees Kelvin) and 150°K (150 degrees Kelvin), such as a temperature of 20°K±10K (20 degrees Kelvin±10 degrees Kelvin) or 90°K±10K (90 degrees Kelvin±10 degrees Kelvin) or 110°K±10K (100 degrees Kelvin±10 degrees Kelvin).

[0024] The above ambient temperature values ​​are suitable for rocket engine cooling: for example, 20°K ± 10°K is suitable for liquid dihydrogen (H2), 90°K ± 10°K for liquid oxygen (O2), and 110°K ± 10°K for liquid methane (CH4).

[0025] In some embodiments, the bimetallic element is composed of two separate materials, one of which is an iron and nickel-based alloy.

[0026] For example, the iron and nickel-based alloy may be Fe-Ni36% (also known as 64FeNi) or INVAR®. Because these materials have very low temperature sensitivity, this allows for better control over the behavior of the two separate material pairs, and thus the behavior of the bimetallic element, as a function of temperature. Specifically, the deformation of the bimetallic element can be considered a function of only one of the two materials, i.e., the material that is not the iron and nickel-based alloy.

[0027] In some embodiments, the valve comprises a heating element configured to heat at least one bimetallic element.

[0028] For example, the heating element may comprise an electrical resistor, for example, the heating element may be controlled to be on / off.

[0029] The heating element allows the bimetallic element to be heated and the valve to close at ambient temperatures cooler than a predetermined temperature, i.e., the valve remains open or the valve reopens if the predetermined temperature is exceeded.

[0030] Additionally, one embodiment relates to a rocket engine including a cooling valve according to any one of the embodiments described in this disclosure.

[0031] The embodiments also relate to a spacecraft comprising a rocket engine according to any one of the embodiments described in the present disclosure.

[0032] The subject matter of the present disclosure and its advantages will be better understood upon reading the following detailed description of different embodiments, illustrated by way of non-limiting examples, which description refers to the attached drawings, in which: [Brief explanation of the drawings]

[0033] [Figure 1] Figure 1 shows a spacecraft equipped with a rocket engine. [Figure 2] FIG. 2 shows a valve of the cooling circuit of the rocket engine of FIG. [Figure 3] FIG. 3 is an axial view of the bimetallic element of the valve of FIG. [Figure 4] FIG. 4 shows a variation of the bimetallic element of FIG. [Figure 5] FIG. 5 shows a variation of the valve of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0034] 1 represents a spacecraft 100 equipped with a rocket engine 50 powered by a tank 60 for cryogenic propellant. The cryogenic propellant contained in the tank 60 can be used, on the one hand, for cooling the rocket engine 50, but, on the other hand, can also be used as fuel for the operation of the rocket engine 50. The propellant used for cooling can be fully or partially recycled, for example, re-injected into the tank 60 or discharged elsewhere. In the following, "fluid" is understood as "cooling fluid", unless otherwise specified.

[0035] The rocket engine 50 comprises a cooling circuit, not shown and known to those skilled in the art. The rocket engine 50 comprises, for example, in the cooling circuit a cooling valve 10 for the rocket engine. Figure 2 shows a schematic diagram of the cooling valve 10.

[0036] The cooling valve 10 includes a casing 12 having a passage 14 extending along an axial direction X. In this example, the casing 12 also extends along the axial direction X. The passage 14 has a fluid inlet 14A (or inlet 14A) and a fluid outlet 14B (or outlet 14B), and fluid can flow from the inlet 14A to the outlet 14B. A valve 16 (or valve body 16) is housed within the casing 12 and is movable along the axial direction X relative to the casing 12 to close or open the passage 12. The valve 16 has a head portion 16A configured to cooperate with a wall of the passage 14 to close or open the passage 14, and a stem 16B extending along the axial direction X. The head portion 16A and the stem 16B are disposed within the passage 12. In this example, the head portion 16A has the shape of a disk having an axis X and extending transversely to the axis X. Head portion 16A is configured to abut seat 13 formed by the wall of the casing that defines passageway 14. Seat 13 is formed by an annular shoulder that separates wide portion 14C from narrow portion 14D of passageway 14. Wide portion 14C is wider than narrow portion 14D, and conversely, narrow portion 14D is narrower than wide portion 14C. In this example, inlet 14A opens into wide portion 14C, while narrow portion 14D opens into outlet 14B.

[0037] The stem 16B is connected to the casing 12 by at least one bimetallic element 18 configured to deform along the axial direction X as a function of the ambient temperature in the passage 14. In this example, the stem 16B is connected to the casing 12 via a single bimetallic element 18. In this example, the stem 16B has two opposite ends 16B1 and 16B2 along the axial direction X, and each end 16B1 and 16B2 is slidably received along the axial direction X in a sleeve 20 connected to the casing 12. Each sleeve 20 extends along the axial direction X in the passage 14. In other words, each sleeve 20 lies on the axis X. In a variant, the valve 10 has more than two sleeves 20 or only one sleeve 20, and the sleeves can be more or less long along the axial direction X. Each sleeve 20 is connected to the casing 12 via a radial arm 20A.

[0038] The bimetallic element 18 engages on the one hand in the annular groove 16B3 of the stem 16B and on the other hand in the annular groove 12A of the casing 12. In this example, the annular groove 16B3 opens radially outward from the valve 10, whereas the annular groove 12A opens radially inward from the valve 10.

[0039] As can be seen in Figure 3, in this example, when viewed in the axial direction X, the bimetallic element 18 has a perforated annular shape, i.e., several holes 17 for the passage of a fluid, with the inner annular edge 18A engaged in the annular groove 16B3, while the outer annular edge 18B is engaged in the annular groove 12A. In the variant shown in Figure 4, when viewed in the axial direction X, the bimetallic element 18' has a substantially rectangular shape, with the short sides of the rectangle engaged in the annular groove 12A. The rectangular shape has a central hole that accommodates the stem 16B, with the edge of this central hole engaging in the annular groove 16B3. Between the long sides of the rectangular shape and the wall forming the passage 12, there is provided a space 17' for the passage of a fluid.

[0040] FIG. 1 depicts valve 10 in an open position. In operation, fluid flows through valve 10, following arrow F, from inlet 12A to outlet 12B, which serves to push head portion 16A toward a closed position, i.e., toward seat 13. Bimetallic element 18 deforms along axial direction X, following arrow D, as a function of fluid temperature, which has the effect of moving head portion 16A closer to or further from seat 13, thereby closing or opening passageway 12. In this example, bimetallic element 18 is configured to deform along axial direction X such that bimetallic element 18 closes passageway 12 when exposed to a predetermined environmental temperature between 10° K and 150° K. In this example, the bimetallic element 18 is comprised of two separate materials 19A and 19B, where one of the two separate materials, e.g., material 19B, is an iron and nickel-based alloy, e.g., Fe-Ni 36% (also known as 64FeNi) or INVAR®, and the other of the two separate materials, e.g., material 19A, is a 300-series austenitic stainless steel. In this example, as shown in FIG. 3 , the valve 10 includes a heating element 22 configured to heat the bimetallic element 18 so as to modify the effective temperature of closure of the bimetallic element 18. In this example, the heating element is an electrical resistor 22 bonded to one side of the bimetallic element 18.

[0041] 5, the valve 10' does not include a sleeve 20, but includes a plurality of bimetallic elements 18, in this example two bimetallic elements 18. The bimetallic element 18' described above can be used instead of the bimetallic element 18, or a combination of bimetallic elements 18, 18' can be used.

[0042] 5, stem 16B is connected to casing 12 by only two separate bimetallic elements 18, with each end 16B1 and 16B2 being bonded to a single bimetallic element 18. Each bimetallic element 18 cooperates with stem 16B and casing 12 in a manner similar to that described above. Operation of valve 10' is similar to that of valve 10.

[0043] While the present invention has been described with reference to particular embodiments, it will be apparent that modifications and variations may be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of different embodiments shown or mentioned may be combined in additional embodiments. Accordingly, the above description and drawings should be considered in an illustrative sense, rather than a restrictive one.

[0044] It is also clear that all features described with reference to a method, either alone or in any combination, can be substituted for the apparatus, and conversely, all features described with reference to an apparatus, either alone or in any combination, can be substituted for the method. The present disclosure also includes the following inventions. The first aspect is A cooling valve (10) for a rocket engine, The cooling valve is a casing (12) having a passage (14) extending along an axial direction (X); a valve (16) accommodated in the casing (12) and movable relative to the casing (12) along the axial direction (X); The cooling valve (10) for a rocket engine includes a stem (16B) extending along an axial direction (X) and a head portion that tightly closes or opens the passage (16B) connected to the stem (16B), and the stem (16B) is connected to the casing (12) by at least one bimetallic element (18, 18') configured to deform along the axial direction (X) as a function of the ambient temperature in the passage (14). The second aspect is A cooling valve (10') in a first embodiment, wherein the stem (16B) is connected to the casing (12) only by two separate bimetallic elements (18, 18'). The third aspect is In a second embodiment of the cooling valve (10'), the stem (16B) has two opposite ends (16B1, 16B2) along the axial direction (X), and each of the two ends (16B1, 16B2) is connected to a single bimetallic element (18, 18'). The fourth aspect is The cooling valve (10) is a cooling valve (10) in a first aspect, which comprises at least one sleeve (20) connected to the casing (12), the at least one sleeve (20) extending along the axial direction (X) within the passage (14) and accommodating the stem (16B) slidably along the axial direction (X), and the stem (16B) is connected to the casing (12) by a single bimetallic element (18, 18'). The fifth aspect is The cooling valve (10) is a cooling valve (10) in a fourth aspect, which has two sleeves (20), and the stem (16B) has two opposite ends (16B1, 16B2) along the axial direction (X), each of the two ends (16B1, 16B2) engaging with one sleeve (20). The sixth aspect is The cooling valve (10, 10') according to any one of the first to fifth aspects, wherein the at least one bimetallic element (18, 18') has a perforated annular or substantially rectangular shape when viewed in the axial direction (X). A seventh aspect is The cooling valve (10, 10') of any one of the first to sixth aspects, wherein the at least one bimetallic element (18, 18') is configured to deform along the axial direction (X) to close the passage (14) when the at least one bimetallic element (18, 18') is exposed to an ambient temperature between 10°K and 150°K, for example, an ambient temperature of 20°K±10°K, or 90°K±10°K, or 110°K±10°K. The eighth aspect is A cooling valve (10, 10') according to any one of the first to seventh aspects, wherein the at least one bimetallic element (18, 18') is made of two separate materials, one of the two separate materials being an iron and nickel-based alloy. A ninth aspect is The cooling valve (10, 10') of any one of the first to eighth aspects, wherein the at least one bimetallic element (18, 18') comprises a heating element (22) configured to heat the at least one bimetallic element (18, 18'). A tenth aspect is A rocket engine (50) including the cooling valve (10, 10') according to any one of the first to ninth aspects.

Claims

1. A cooling valve (10) for a rocket engine, The cooling valve is a casing (12) having a passage (14) extending along an axial direction (X); a valve (16) accommodated in the casing (12) and movable relative to the casing (12) along the axial direction (X); The cooling valve (10) for a rocket engine, wherein the valve (16) comprises a stem (16B) extending along an axial direction (X) and a head portion that tightly closes or opens the passage (16B) connected to the stem (16B), and the stem (16B) is connected to the casing (12) by at least one bimetallic element (18, 18') configured to deform along the axial direction (X) as a function of the ambient temperature in the passage (14).

2. 2. The cooling valve (10') of claim 1, wherein the stem (16B) is connected to the casing (12) by only two separate bimetallic elements (18, 18').

3. 3. The cooling valve (10') according to claim 2, wherein the stem (16B) has two ends (16B1, 16B2) opposite to each other along the axial direction (X), and each of the two ends (16B1, 16B2) is connected to a single bimetallic element (18, 18').

4. 2. The cooling valve (10) of claim 1, further comprising at least one sleeve (20) connected to the casing (12), the at least one sleeve (20) extending along the axial direction (X) within the passage (14) and accommodating the stem (16B) slidably along the axial direction (X), the stem (16B) being connected to the casing (12) by a single bimetallic element (18, 18').

5. 5. The cooling valve (10) according to claim 4, wherein the cooling valve (10) comprises two sleeves (20), and the stem (16B) has two ends (16B1, 16B2) opposite to each other along the axial direction (X), each of the two ends (16B1, 16B2) being engaged with one sleeve (20).

6. The cooling valve (10, 10') according to any one of claims 1 to 5, wherein the at least one bimetallic element (18, 18') has a perforated annular or substantially rectangular shape when viewed in the axial direction (X).

7. 7. The cooling valve (10, 10') according to any one of claims 1 to 6, wherein the at least one bimetallic element (18, 18') is configured to deform along the axial direction (X) to close the passage (14) when the at least one bimetallic element (18, 18') is exposed to an ambient temperature between 10°K and 150°K.

8. The cooling valve (10, 10') according to any one of claims 1 to 7, wherein the at least one bimetallic element (18, 18') is made of two separate materials, one of the two separate materials being an iron and nickel based alloy.

9. The cooling valve (10, 10') according to any one of claims 1 to 8, wherein the at least one bimetallic element (18, 18') comprises a heating element (22) configured to heat the at least one bimetallic element (18, 18').

10. A rocket engine (50) comprising a cooling valve (10, 10') according to any one of claims 1 to 9.

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