PRESSURIZATION METHOD FOR PRESSURIZING A PROPELLANT TANK, FILLING METHOD, TANK ASSEMBLY, FILLING SYSTEM, AND SPACECRAFT

Abstract

A pressurization method for increasing a pressure within a propellant tank containing hydrogen peroxide H.sub.2O.sub.2. The pressurization method includes irradiating at least some of the hydrogen peroxide H.sub.2O.sub.2 with ultraviolet light emitted by at least one ultraviolet light source. With the UV light, a photolysis is actively provoked which causes the irradiated hydrogen peroxide H.sub.2O.sub.2 to at least partially decompose into water H.sub.2O and gaseous oxygen O.sub.2. Also a filling method for at least partially filling a receiving propellant tank with the pressurization method, a tank assembly, a filling system, and a spacecraft.

Claims

1. A method for increasing a pressure within a propellant tank containing hydrogen peroxide (H.sub.2O.sub.2), the method comprising: irradiating at least some of the hydrogen peroxide with ultraviolet light emitted by at least one ultraviolet light source, thereby provoking a photolysis causing an irradiated hydrogen peroxide (H.sub.2O.sub.2) to at least partially decompose into water (H.sub.2O) and gaseous oxygen (O.sub.2).

2. The method according to claim 1, wherein the at least one ultraviolet light source is at least partially covered with a protection which is transparent for ultraviolet light and made of at least one of: fluorinated ethylene propylene, a perfluoroalkoxy alkane: a transparent metal compatible with hydrogen peroxide; a transparent ceramic compatible with hydrogen peroxide; or any combination thereof.

3. The method according to claim 1, further comprising: controlling the photolysis by selectively switching the at least one ultraviolet light source on or off, or by controlling a dimmer of the at least one ultraviolet light source, or by both.

4. The method according to claim 1, wherein the propellant tank is a plain tank.

5. The method according to claim 1, wherein the propellant tank is a bladder tank with at least one bladder separating an interior of the propellant tank into one or more propellant compartments containing a propellant, or into an ullage containing the hydrogen peroxide (H.sub.2O.sub.2) at least some of which is irradiated, or into both.

6. The method according to claim 5, wherein the propellant is hydrogen peroxide.

7. The method according to claim 1, wherein the propellant tank is installed in a vehicle.

8. A method for at least partially filling a receiving propellant tank, the method comprising: carrying out the method according to claim 1, thereby pressurizing a supplying propellant tank; and urging, with an increased pressure within the supplying propellant tank, at least some of a propellant of the supplying propellant tank through a propellant transfer system into a receiving propellant tank.

9. A tank assembly comprising a propellant tank configured to contain hydrogen peroxide (H.sub.2O.sub.2), and at least one ultraviolet light source configured to emit ultraviolet light irradiating at least some of the hydrogen peroxide (H.sub.2O.sub.2) respectively contained in the propellant tank, thereby provoking a photolysis thereof into water (H.sub.2O) and gaseous oxygen (O.sub.2).

10. The tank assembly according to claim 9, wherein the at least one ultraviolet light source is at least partially covered by a protection which is transparent for ultraviolet light and at least partially made of: fluorinated ethylene propylene; a perfluoroalkoxy alkane; a transparent metal which is compatible with hydrogen peroxide; a transparent ceramic which is compatible with hydrogen peroxide; or any combination thereof.

11. The tank assembly according to claim 9, further comprising: a tank pressure control system configured to arrange for a pressure within the propellant tank being in a predefined range by automatically switching the at least one ultraviolet light source selectively on or off, or by automatically dimming the at least one ultraviolet light source, or by both.

12. The tank assembly according to claim 9, wherein the propellant tank is a plain tank.

13. The tank assembly according to claim 9, wherein the propellant tank is a bladder tank comprising at least one bladder partitioning an interior of the propellant tank into one or more propellant compartments configured to contain a propellant, or into an ullage containing the irradiated hydrogen peroxide (H.sub.2O.sub.2), or into both.

14. A filling system for at least partially filling a receiving propellant tank, the filling system comprising: the tank assembly according to claim 13, whose propellant tank is designated as a supplying propellant tank, and a propellant transfer system connected or configured to connect to at least one of the one or more propellant compartments of the supplying propellant tank of the tank assembly and releasably connected or configured to releasably connect to the receiving propellant tank.

15. A spacecraft comprising: the tank assembly according to claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Shown is schematically:

[0038] FIG. 1a is an exemplary embodiment of a tank assembly according to the present invention in a first state;

[0039] FIG. 1b is the tank assembly of FIG. 1a in a second state;

[0040] FIG. 2a is another exemplary embodiment of a tank assembly according to the present invention in a first state;

[0041] FIG. 2b is the tank assembly of FIG. 2a in a second state;

[0042] FIG. 3a is a further exemplary embodiment of a tank assembly according to the present invention in a first state;

[0043] FIG. 3b is the tank assembly of FIG. 3a in a second state; and

[0044] FIG. 4 is a filling system according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] FIGS. 1a and 1b schematically illustrate a tank assembly 1 according to a first embodiment of the present invention in respective situations. The tank assembly 1 comprises a propellant tank 10 configured as a bladder tank, and an ultraviolet light source 20 which is electrically connected to a power source (not shown) by an electric line 21.

[0046] Preferably, a (not shown) protection which is transparent for ultraviolet light (i.e., which unhamperedly lets the ultraviolet light L pass through and which has an ultraviolet light permeability of at least 90% or at least 95% or at least 97%) at least partially covers the ultraviolet light source 20 so as to protect it against damage and/or impacts of hydrogen peroxide H.sub.2O.sub.2 in its vicinity.

[0047] The ultraviolet light source 20 is arranged in an ullage 200 of the propellant tank 10, which ullage 200 is separated by a bladder 11 from a propellant compartment 100 of the propellant tank 10. The bladder preferably is impermeable for ultraviolet light. In particular, it may advantageously comprise pigmented fluorinated ethylene propylene and/or pigmented (black) perfluoroalkoxy alkane.

[0048] A closable propellant transfer system 30, only a portion of which is shown in FIGS. 1a, 1b connects the propellant compartment 100 with another unit (not shown) such as another vessel or a consumer unit (e.g., an engine to be driven by the propellant).

[0049] In the situation depicted in FIG. 1a, the ullage 200 contains hydrogen peroxide H.sub.2O.sub.2, and the propellant compartment 100 is filled with a propellant P which may be further hydrogen peroxide, ethanol, kerosene, or another storable propellant. The ultraviolet light source 20 irradiates at least some of the hydrogen peroxide H.sub.2O.sub.2 within the ullage 200 with ultraviolet light L.

[0050] Thereby, a photolysis is provoked (not visible in FIG. 1a) which causes the hydrogen peroxide H.sub.2O.sub.2 within the ullage 200 to at least partially decompose into gaseous oxygen and water, these decomposition products together having a larger volume than the amount of irradiated hydrogen peroxide H.sub.2O.sub.2 they originate from. As a consequence, a pressure within the propellant tank 10 raises. By selectively switching the ultraviolet light source 20 on or off, a respectively required pressure within the propellant tank 10 can be adjusted.

[0051] FIG. 1b depicts a situation in which the hydrogen peroxide H.sub.2O.sub.2 previously contained in the ullage 200 has (at least almost) completely decomposed into oxygen O.sub.2 and water H.sub.2O now contained in the ullage 200.

[0052] Therein, the pressure increased by the photolysis has been utilized to urge a portion of the propellant P, through the opened propellant transfer system 30, to another unit (not shown). The propellant transfer could be carried out without involvement of a pump. As apparent from a comparison of FIGS. 1a and 1b, it caused a volume reduction of the propellant compartment 100 and a volume raise of the ullage 200.

[0053] FIGS. 2a, 2b similarly illustrate a tank assembly l according to a second embodiment of the present invention in respective situations. The tank assembly 1 comprises a propellant tank 10 configured as a bladder tank which in this case includes two propellant compartments 100a, 100b separated from an ullage 200 by respective bladders 11a, 11b which preferably are impermeable for ultraviolet light.

[0054] In the situation depicted in FIG. 2a, the ullage 200 contains hydrogen peroxide H.sub.2O.sub.2, and the propellant compartments 100a, 100b are filled with a propellant P which may be further hydrogen peroxide, ethanol, kerosene, or another storable propellant. Though not shown in FIGS. 2a, 2b, propellant compartments 100a, 100b of such tank assembly l might even contain different propellants.

[0055] The tank assembly 1 further comprises an ultraviolet light source 20 which in this case is configured as a bar extending into an interior of the ullage 200 and which is connected to a (not shown) power source by an electric line 21. Analogously to what is described above with respect to FIG. 1a, 1b, the ultraviolet light source 20 preferably is at least partially covered with a (not shown) protection which is transparent for ultraviolet light.

[0056] As illustrated in FIG. 2a, the ultraviolet light source 20 irradiates at least some of the hydrogen peroxide H.sub.2O.sub.2 within the ullage 200 with ultraviolet light L.

[0057] The irradiation will provoke a photolysis causing the hydrogen peroxide H.sub.2O.sub.2 within the ullage 200 to at least partially decompose into oxygen and water. As a consequence, a pressure within the propellant tank 10 raises. By selectively switching the ultraviolet light source 20 on or off, a respectively required pressure within the propellant tank 10 can be adjusted.

[0058] FIG. 2b depicts a situation in which the hydrogen peroxide H.sub.2O.sub.2 previously contained in the ullage 200 has (at least almost) completely decomposed into oxygen O.sub.2 and water H.sub.2O now contained in the ullage 200.

[0059] Therein, the pressure increased by the photolysis has been utilized to urge a portion of the propellant P, through opened propellant transfer systems 30a, 30b, from the propellant compartments 100a, 100b to at least one further unit (not shown). This propellant transfer could be carried out without involvement of a pump. As apparent from a comparison of FIGS. 2a and 2b, it caused a volume reduction of the propellant compartments 100a, 100b and a volume raise of the ullage 200.

[0060] In FIGS. 3a, 3b a tank assembly 1 according to a further embodiment of the present invention is schematically shown in respective situations. The tank assembly 1 comprises a propellant tank 10 which in this embodiment is a plain tank, and an ultraviolet light source 20 connected to a (not shown) electric power source by an electric line 21. Again, the ultraviolet light source 20 may preferably be at least partially covered with a protection which is transparent for ultraviolet light.

[0061] In the situations shown in FIGS. 3a, 3b, the propellant tank 10 contains hydrogen peroxide H.sub.2O.sub.2 and gaseous oxygen O.sub.2. At least some of the hydrogen peroxide H.sub.2O.sub.2 is irradiated, by the ultraviolet light source 20, with ultraviolet light L.

[0062] FIG. 3a depicts a beginning of the irradiation, and it illustrates a penetration depth d of the ultraviolet light L into the hydrogen peroxide H.sub.2O.sub.2, the penetration depth d depending on a power of the at least one ultraviolet light source 20, and on wavelengths of the ultraviolet light L it emits.

[0063] As apparent from FIG. 3a, a sub-amount of the hydrogen peroxide H.sub.2O.sub.2 which is located beyond the penetration depth d is not reached by the ultraviolet light L. As a consequence, the irradiation will not cause the hydrogen peroxide H.sub.2O.sub.2 of this sub-amount to decompose.

[0064] FIG. 3b illustrates the tank assembly 1 in a more advanced state of the irradiation. In this situation, some of the hydrogen peroxide H.sub.2O.sub.2 has decomposed by the photolysis caused by the irradiation. As a consequence, bubbles of gaseous oxygen O.sub.2 and bubbles of water H.sub.2O have emerged within a decomposition depth D of the hydrogen peroxide, and the gaseous oxygen O.sub.2 has been compressed.

[0065] Thereby, a pressure in the propellant tank 10 has been increased. The pressure raise may then be used to urge at least some of the hydrogen peroxide H.sub.2O.sub.2 through a propellant transfer system 30 to another unit such as an engine of a vehicle (in particular, of a spacecraft, for example) or another vessel (not shown).

[0066] In FIG. 4, a filling system 1.sub.F according to an exemplary embodiment of the present invention is depicted. The filling system 1.sub.F comprises a tank assembly 1 according to an embodiment of the present invention, a propellant tank 10.sub.V serving, in the filling system 1.sub.F, as a receiving propellant tank, and a propellant transfer system 30 connecting the tank assembly 1 and the receiving propellant tank 10.sub.V to which the propellant transfer system 30 is releasably connected.

[0067] The tank assembly 1 comprises a propellant tank 10 which in this case serves as a supplying propellant tank and which is configured as a bladder tank including a propellant compartment 100 and an ullage 200 with are separated from each other by a bladder 11. Preferably, the propellant tank 10 is adapted to be arranged on a logistic transportation vehicle such as a truck, a goods wagon, or a freighter (not shown). The tank assembly 1 further comprises an ultraviolet light source 20 which is connected to a (not shown) electric power source by an electric line 21.

[0068] Also the receiving propellant tank 10.sub.V is configured as a bladder tank, having a bladder 11.sub.V partitioning an interior of the propellant vessel 10.sub.V into a propellant compartment 100.sub.V and an ullage 200.sub.V. The ullage 200.sub.V preferably is filled with gas such as oxygen. The propellant vessel 10.sub.V in particular may be installed in a vehicle such as a spacecraft (not shown).

[0069] In the situation depicted in FIG. 4, the propellant compartment 100 of the tank assembly 1 is filled with a propellant P (such as hydrogen peroxide, ethanol, kerosene, or another storable propellant), and the ullage 200 of the tank assembly 1 contains hydrogen peroxide H.sub.2O.sub.2 at least some of which is irradiated, by the ultraviolet light source 20, with ultraviolet light L.

[0070] As a consequence, a photolysis and, thereby, a decomposition of at least some of the hydrogen peroxide H.sub.2O.sub.2 within the ullage 200 into oxygen and water will be caused (not shown), such that a pressure in the propellant tank 1, in particular in its ullage 200 will increase. The thus increased pressure may then be utilized to urge, preferably without involvement of a propellant pump, at least some of the propellant P through the propellant transfer system 30 into the receiving propellant tank 10.sub.V, in particular, into the propellant compartment 100 thereof.

[0071] In this way, the receiving propellant tank 10.sub.V can be at least partially filled.

[0072] The receiving propellant tank 10.sub.V may preferably comprise a pressurization system (not shown) advantageously facilitating a subsequent extraction of the gas. In particular, the receiving propellant tank 200.sub.V may be constructed analogous to the supplying propellant tank. It may thus be configured to contain hydrogen peroxide in its ullage 200.sub.V, and it may comprise at least one ultraviolet light source configured to irradiate this hydrogen peroxide with ultraviolet light (not shown).

[0073] Disclosed is a pressurization method for increasing a pressure within a propellant tank 10, 10, 10, 10 containing hydrogen peroxide H.sub.2O.sub.2. The pressurization method comprises irradiating at least some of the hydrogen peroxide H.sub.2O.sub.2 with ultraviolet light L emitted by at least one ultraviolet light source 20, 20, 20, 20. Thereby, a photolysis is actively provoked which causes the irradiated hydrogen peroxide H.sub.2O.sub.2 to at least partially decompose into water H.sub.2O and gaseous oxygen O.sub.2.

[0074] Further disclosed are a filling method for at least partially filling a receiving propellant tank 10.sub.V by applying such pressurization method, a tank assembly 1, 1, 1, 1, a filling system 1.sub.F, and a spacecraft.

[0075] The systems and devices described herein may include a controller or a computing device comprising a processing unit and a memory which has stored therein computer-executable instructions for implementing the processes described herein. The processing unit may comprise any suitable devices configured to cause a series of steps to be performed so as to implement the method such that instructions, when executed by the computing device or other programmable apparatus, may cause the functions/acts/steps specified in the methods described herein to be executed. The processing unit may comprise, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, a central processing unit (CPU), an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuits, or any combination thereof.

[0076] The memory may be any suitable known or other machine-readable storage medium. The memory may comprise non-transitory computer readable storage medium such as, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The memory may include a suitable combination of any type of computer memory that is located either internally or externally to the device such as, for example, random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like. The memory may comprise any storage means (e.g., devices) suitable for retrievably storing the computer-executable instructions executable by processing unit.

[0077] The methods and systems described herein may be implemented in a high-level procedural or object-oriented programming or scripting language, or a combination thereof, to communicate with or assist in the operation of the controller or computing device. Alternatively, the methods and systems described herein may be implemented in assembly or machine language. The language may be a compiled or interpreted language. Program code for implementing the methods and systems described herein may be stored on the storage media or the device, for example a ROM, a magnetic disk, an optical disc, a flash drive, or any other suitable storage media or device. The program code may be readable by a general or special-purpose programmable computer for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein.

[0078] Computer-executable instructions may be in many forms, including modules, executed by one or more computers or other devices. Generally, modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically, the functionality of the modules may be combined or distributed as desired in various embodiments.

[0079] It will be appreciated that the systems and devices and components thereof may utilize communication through any of various network protocols such as TCP/IP, Ethernet, FTP, HTTP and the like, and/or through various wireless communication technologies such as GSM, CDMA, Wi-Fi, and WiMAX, is and the various computing devices described herein may be configured to communicate using any of these network protocols or technologies.

[0080] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

REFERENCE SIGNS

[0081] 1, 1, 1, 1 tank assembly [0082] 1.sub.F filling system [0083] 10, 10, 10, 10 propellant tank [0084] 10.sub.V receiving propellant tank [0085] 11, 11a, 11b, 11, 11.sub.V bladder [0086] 20, 20, 20, 20 ultraviolet light source [0087] 21, 21, 21, 21 electric line [0088] 30, 30a, 30b, 30, 30 propellant transfer system [0089] 100, 100a, 100b, 100, 100.sub.V propellant compartment [0090] 200, 200, 200, 200.sub.V ullage [0091] d light penetration depth [0092] D decomposition depth [0093] L ultraviolet light [0094] P propellant