Fuel isolation system with ruptured diaphragm

Abstract

The fuel isolation system includes a valve body that defines a flow passage extending from an inlet to an outlet, a rupture diaphragm in the flow passage and fluidly sealing the inlet relative to the outlet, and an actuator positioned adjacent to the rupture diaphragm. The rupture diaphragm is integral with the valve body. The actuator includes a plunger configured to move and cause rupture of the rupture diaphragm and thereby fluidly connect the inlet and the outlet.

Description

Background Art

[0001] Vehicles burn fuel for propulsion and / or orientation adjustment. In some types of vehicles, fuel may be contained within a segregated section of the vehicle's fuel system until "start-up". The segregated section is robust to ensure leak-free control. When starting up, the fuel is released from the segregated section, making the vehicle operable for propulsion and / or orientation adjustment. Summary of the Invention

[0002] According to an example of the present disclosure, a fuel isolation system includes a valve body that defines a flow channel extending from an inlet to an outlet, and a rupture diaphragm integrated with the valve body. The rupture diaphragm is in the flow channel and fluid-seals the inlet relative to the outlet. An actuator is positioned adjacent to the rupture diaphragm. The actuator includes a plunger configured to move and cause rupture of the rupture diaphragm, and thereby fluid-connect the inlet and the outlet. A propellant tank has an inlet attached to or integrated with the valve body.

[0003] In another embodiment of any of the foregoing embodiments, the actuator is a thermal actuator.

[0004] In another embodiment of any of the foregoing embodiments, the actuator is a wax actuator.

[0005] In another embodiment of any of the foregoing embodiments, the plunger is a piston.

[0006] In another embodiment of any of the foregoing embodiments, the plunger is configured to pierce the rupture diaphragm.

[0007] In another embodiment of any of the foregoing embodiments, the rupture diaphragm has at least one score line.

[0008] In another embodiment of any of the foregoing embodiments, the rupture diaphragm is curved.

[0009] Another embodiment of any of the foregoing embodiments includes a blade adjacent to the rupture diaphragm and located on the side of the diaphragm opposite the actuator.

[0010] In another embodiment of any of the foregoing embodiments, the rupture diaphragm is welded to the valve body.

[0011] In another embodiment of any of the foregoing embodiments, the rupture diaphragm is metallic.

[0012] In another embodiment of any of the foregoing embodiments, in addition to the inlet and the outlet, the valve body defines a test port that opens into the flow channel and is fluid-connected to the outlet rather than the inlet.

[0013] In another embodiment of any of the foregoing embodiments, the outlet includes a filter.

[0014] In another embodiment of any of the foregoing embodiments, the outlet includes a venturi tube.

[0015] Another embodiment of any of the foregoing embodiments includes a fuel tank connected to the inlet.

[0016] In another embodiment of any of the foregoing embodiments, the propellant tank contains pressurized hydrazine.

[0017] In another embodiment, the fuel isolation system of any of the foregoing embodiments is in a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] For those skilled in the art, the various features and advantages of the present disclosure will become apparent from the following detailed description. The accompanying drawings, which accompany the detailed description, can be briefly described as follows.

[0019] Figure 1 An example fuel system in a spacecraft is illustrated.

[0020] Figure 2 The isolation valve of the fuel system is illustrated, and the isolation valve is in an actuated state to rupture a rupture diaphragm.

[0021] Figure 3 An isolated view of an example rupture diaphragm is illustrated.

[0022] Figure 4 Another example isolation valve configured with a test port is illustrated.

[0023] Figure 5 Another example isolation valve is illustrated, in which there is a cutting edge adjacent to the diaphragm section. DETAILED DESCRIPTION

[0024] The mechanism for controlling the release of fuel from the isolation section of a fuel system in a vehicle can be relatively complex. Such mechanisms must be reliably controlled and operated to initiate the release of fuel only at the desired time. As can be understood, to meet these requirements, such mechanisms may have a relatively complex design. Although these solutions are effective, they may increase costs, not only from the design itself, but also from the installation steps and quality assurance measures. Along these lines, as will be apparent from the present disclosure, the unique fuel isolation system herein attempts to provide a reliable and cost-effective option for controlling the initiation of fuel release.

[0025] Figure 1 An example fuel system 20 (“system 20”) is schematically illustrated. As shown, system 20 is in a vehicle, which is generally labeled at 22. For example, vehicle 22 is a satellite, although the present disclosure is applicable to other types of vehicles.

[0026] System 20 includes an isolation valve 24 that is fluidly connected to an outlet 25 of a fuel tank 26 that may contain a fuel 26a, such as hydrazine. For example, the outlet 25 is attached to or integral with the isolation valve 24. The isolation valve 24 serves to isolate the fuel 26a from the remainder of the fuel system 20, which is generally designated at 28. As will be appreciated, the remainder of the fuel system 28 can include fluid lines, valves, injectors, and other engine or thruster components that are well known in the art.

[0027] The isolation valve 24 is formed by a valve body 30. The valve body 30 is formed of a metal alloy and can have a single-piece or multi-piece construction, so long as it is leak-free under pressure and in the operating conditions. The valve body 30 includes an inlet 32, an outlet 34, and a flow passage 36 that extends from the inlet 32 to the outlet 34. The inlet 32 is welded to the outlet 25 of the fuel tank 26. In this example, the isolation valve has an "elbow" configuration such that the flow passage 36 turns approximately 90 degrees. However, it should be understood that the geometry of the isolation valve 24 and the path of the flow passage 36 can vary.

[0028] The isolation valve 24 also includes a rupture diaphragm 38 located in the flow passage 36 and an actuator 40 positioned adjacent to the rupture diaphragm 38. The rupture diaphragm 38 fluidly seals the inlet 32 relative to the outlet 34. The actuator 40 includes a plunger 40a that is configured to move in an extended manner (as shown by arrow 42). The actuator 40 is positioned such that the plunger 40a can extend over a stroke that intersects the rupture diaphragm 38. For example, the stroke is approximately half an inch and applies a force of approximately 100 pounds. The rupture diaphragm 38 is fragile under the impact of the plunger 40a such that the extension of the plunger 40a causes the rupture of the rupture diaphragm 38.

[0029] In one example, the actuator 40 is a thermal actuator. One example of a thermal actuator is a wax actuator, such as a paraffin wax actuator. The thermal actuator converts thermal energy into mechanical energy in the form of the extension of the plunger 40a. In one paraffin-based example, the actuator 40 includes a heater operable to heat the paraffin to a temperature above the melting temperature of the paraffin (about 176°F). The wax melts and expands, and this expansion causes the extension of the plunger 40a. As will be appreciated, other types of actuators can be used; however, wax actuators have a relatively simple binary on / off operation to activate the heater and are inexpensive.

[0030] Prior to rupture ( Figure 1),The rupture diaphragm 38 seals the inlet 32 relative to the outlet 34, such that the fuel 26a remains isolated within the system 20. When the system 20 is to be activated to release the fuel, the actuator 40 is actuated to extend the plunger 40a, such that the spacecraft 22 becomes operable for propulsion and / or orientation adjustment. As Figure 2 shown, upon actuation, the plunger 40a extends and breaches the rupture diaphragm 38. Once breached, the inlet 32 and the outlet 34 become fluidly connected, thereby allowing the fuel to flow through the isolation valve 24 to the remainder 28 of the system 20 for propulsion and / or orientation adjustment. In another example, the isolation valve 24 can be reused by removing the breached rupture diaphragm 38 and replacing it with a new, unbreached rupture diaphragm 38.

[0031] Figure 3 An isolated view of an example of the rupture diaphragm 38 is illustrated. The rupture diaphragm 38 includes a diaphragm section 38a and an edge 38b. The diaphragm section 38a in this example is metallic and can be formed of titanium or aluminum alloy. In view of this, the rupture diaphragm 38 is generally rigid, although alternatively it can be flexible so long as it can maintain the isolation of the fuel 26a.

[0032] In this example, the diaphragm section 38a is partially spherical and convex (towards the plunger �0a). Such a geometry allows the diaphragm section 38a to be relatively close to the plunger 40a, thereby reducing the stroke length required for breaching. If the design envelope and the stroke length allow, the diaphragm section 38a can alternatively have a conical, pyramidal, or other geometry and can be concave or even planar.

[0033] In the illustrated example, the surface of the diaphragm section 38a has at least one score line 38c. The score line 38c is a groove in the surface that serves to weaken the diaphragm section 38a to facilitate breaching by the plunger 40a. The edge 38b allows the diaphragm 38 to be secured within the valve body 30 of the isolation valve 24 in a leak-free manner. For example, as Figure 1 shown, the diaphragm 38 is integrated into the valve body 30 (i.e., made integral therewith) via the edge 38b that is welded to the flange 32a of the inlet 32. Additionally or alternatively, part or all of the diaphragm 38 is machined within the valve body 30.

[0034] Figure 4Another example isolation valve 124 is illustrated. In the present disclosure, like reference numerals denote like elements where appropriate, and reference numerals with a hundred or multiple thereof added denote modified elements, which are understood to incorporate the same features and benefits of the corresponding elements. In this example, the isolation valve 124 is configured for flow testing. In view of this, in addition to the inlet 32 and the outlet 34, the valve body 30 further defines a test port 46 that opens into the flow passage 36, and the test port 46 is fluidly connected to the outlet 34 rather than the inlet 32 (at least prior to the rupture of the rupture diaphragm 38). The test port 46 can be adapted to the desired form of a connector for attaching various test equipment. The outlet 34 includes a filter 48 and a venturi tube 50. The filter 48 functions to facilitate the removal of impurities in the test fluid, and the venturi tube helps to reduce water hammer.

[0035] Figure 5 Another example isolation valve 224 is illustrated. In this example, the isolation valve 224 includes at least one cutting edge 52 adjacent to the rupture diaphragm 38. The cutting edge 52 is located on the side of the rupture diaphragm 38 opposite to the plunger 140a of the actuator 40. When the plunger 140a extends, it deflects the diaphragm section 38a towards the cutting edge 52. When an impact occurs between the cutting edge 52 and the diaphragm section 38a, the cutting edge 52 ruptures the diaphragm section 38a. This rupture can occur by cutting, piercing, tearing, or other means sufficient to rupture the rupture diaphragm 38, such that the inlet 32 and the outlet 34 become fluidly connected, thereby allowing fuel to flow through the isolation valve 224 for propulsion and / or orientation adjustment.

[0036] Although the combination of features is shown in the illustrated examples, not all features need to be combined to achieve the benefits of the various embodiments of the present disclosure. In other words, a system designed in accordance with an embodiment of the present disclosure will not necessarily include all the features shown in any one figure or all the parts schematically shown in the figures. Additionally, selected features of one example embodiment can be combined with selected features of other example embodiments.

[0037] The foregoing description is exemplary in nature and not restrictive. Variations and modifications to the disclosed examples may become apparent to those skilled in the art, and these variations and modifications do not necessarily depart from the present disclosure. The scope of legal protection afforded to the present disclosure can only be determined by studying the following claims.

Claims

1. A fuel isolation system, comprising: a valve body that defines a flow passage extending from an inlet to an outlet; a rupture diaphragm that is integrated with the valve body, the rupture diaphragm being located in the flow passage and fluid-tightly sealing the inlet relative to the outlet; an actuator positioned adjacent to the rupture diaphragm, the actuator including a plunger configured to move and cause rupture of the rupture diaphragm, and thereby fluidly connect the inlet and the outlet; and a propellant tank having an inlet attached to or integrated with the inlet of the valve body; the actuator includes paraffin wax and a heater operable to melt the paraffin wax, wherein the paraffin wax is configured to expand when melted and cause extension of the plunger to cause rupture of the rupture diaphragm; in addition to the inlet and the outlet, the valve body defines a test port that opens into the flow passage and is fluidly connected to the outlet rather than the inlet, the test port being positioned opposite to the outlet.

2. The fuel isolation system according to claim 1, wherein The actuator is a thermal actuator.

3. The fuel isolation system according to claim 1, wherein The plunger is a piston.

4. The fuel isolation system according to claim 1, wherein, The plunger is configured to pierce the rupture diaphragm.

5. The fuel isolation system according to claim 1, wherein The rupture diaphragm has at least one score line.

6. The fuel isolation system according to claim 1, wherein, The rupture diaphragm is curved.

7. The fuel isolation system according to claim 1, further comprising a cutting edge adjacent to the rupture diaphragm, and the cutting edge is located on a side of the diaphragm opposite to the actuator.

8. The fuel isolation system according to claim 1, wherein The rupture diaphragm is welded to the valve body.

9. The fuel isolation system according to claim 1, wherein, The rupture diaphragm is metallic.

10. The fuel isolation system according to claim 1, wherein, The outlet includes a filter.

11. The fuel isolation system according to claim 10, wherein, The outlet includes a venturi tube.

12. The fuel isolation system according to claim 1, further comprising a fuel tank connected to the inlet.

13. The fuel isolation system according to claim 12, wherein, The propellant tank contains pressurized hydrazine.

14. A vehicle comprising the fuel isolation system according to claim 1.

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