Centrifugal reservoir pump used for processing a hydrogen stream in an aircraft

Abstract

A centrifugal reservoir pump for processing a hydrogen stream in an aircraft. In particular, a centrifugal reservoir pump including a pump casing, a hydrogen stream inlet, a rotor being rotatably arranged in the interior part of the pump and including rotor vanes for accelerating the hydrogen stream, and two hydrogen stream outlets. Further provided is a tank unit including the centrifugal reservoir pump and a reservoir for hydrogen. Further provided is an aircraft including a centrifugal reservoir pump or a tank unit. Further provided is a method of processing hydrogen in an aircraft.

Claims

1. A centrifugal reservoir pump, used for processing a hydrogen stream in an aircraft, comprising: a pump casing encompassing an interior part of the pump; a hydrogen stream inlet; a rotor being rotatably arranged in the interior part of the pump and comprising rotor vanes for accelerating the hydrogen stream perpendicular to a rotating axis of the rotor and for accelerating the hydrogen stream in a circumferential direction; and a first hydrogen stream outlet and a second hydrogen stream outlet, wherein the pump casing comprises a pump housing and a cage, wherein the cage is rotatably arranged, and, wherein the cage, being rotatably arranged, comprises through-holes for passing liquid hydrogen into a gap between the pump housing and the cage enabling a hydrostatic bearing.

2. The pump according to claim 1, wherein at least one of a distance of the first hydrogen stream outlet to the rotating axis is larger than a distance of the second hydrogen stream outlet to the rotating axis.

3. The pump according to claim 1, wherein the pump is used for processing the hydrogen stream comprising a liquid hydrogen stream portion and a gaseous hydrogen stream portion and the first hydrogen stream outlet is configured to allow an unloading of the liquid hydrogen stream portion out of the pump and the second hydrogen stream outlet is configured to allow an unloading of the gaseous hydrogen stream portion out of the pump.

4. The pump according to claim 1, wherein at least one of the first hydrogen stream outlet or the second hydrogen stream outlet comprises a pitot tube, wherein the pitot tube vertically faces the circumferential direction.

5. The pump according to claim 1, wherein the rotor vanes represent rotor tubes for passing the hydrogen stream within the rotor tubes from the hydrogen stream inlet into the interior part of the pump.

6. The pump according to claim 1, wherein the rotor comprises a shaft forming a shaft tube connecting the hydrogen stream inlet with the interior part of the pump, and wherein a low pressure mechanical seal is arranged downstream of the hydrogen stream inlet and upstream of the shaft tube.

7. The pump according to claim 4, wherein at least one of the first hydrogen stream outlet or the second hydrogen stream outlet comprising the pitot tube further comprises a final tube portion downstream the pitot tube, wherein the final tube portion is arranged adjacent to the hydrogen stream inlet.

8. A tank unit for the aircraft comprising a reservoir for hydrogen, and the pump according to claim 1.

9. The tank unit according to claim 8, wherein the reservoir for the hydrogen is surrounded by a multilayer insulation.

10. The tank unit according to claim 8, wherein the reservoir for the hydrogen is surrounded by a multilayer insulation configured for thermal isolation between an inner part and an outer part of the reservoir for the hydrogen.

11. An aircraft comprising: a pump comprising: a pump casing encompassing an interior part of the pump; a hydrogen stream inlet; a rotor being rotatably arranged in the interior part of the pump and comprising rotor vanes for accelerating the hydrogen stream perpendicular to a rotating axis of the rotor and for accelerating the hydrogen stream in a circumferential direction; and a first hydrogen stream outlet and a second hydrogen stream outlet, wherein the pump casing comprises a pump housing and a cage, wherein the cage is rotatably arranged, and, wherein the cage, being rotatably arranged, comprises through-holes for passing liquid hydrogen into a gap between the pump housing and the cage enabling a hydrostatic bearing.

12. An aircraft comprising: a tank unit comprising: a reservoir for hydrogen; and, a pump comprising: a pump casing encompassing an interior part of the pump; a hydrogen stream inlet; a rotor being rotatably arranged in the interior part of the pump and comprising rotor vanes for accelerating the hydrogen stream perpendicular to a rotating axis of the rotor and for accelerating the hydrogen stream in a circumferential direction; and a first hydrogen stream outlet and a second hydrogen stream outlet, wherein the pump casing comprises a pump housing and a cage, wherein the cage is rotatably arranged, and, wherein the cage, being rotatably arranged, comprises through-holes for passing liquid hydrogen into a gap between the pump housing and the cage enabling a hydrostatic bearing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics, advantages and application options of the present invention are disclosed in the following description of the exemplary embodiments in the figures. All the described and/or illustrated characteristics per se and in any combination form the subject of the invention, even irrespective of their composition in the individual claims or their interrelationships.

(2) FIG. 1 shows the general principle with examples of potential pitot tube outlets or flush outlets.

(3) FIG. 2 shows the rotating cage pitot tube pump with two pitot outlets.

(4) FIG. 3 shows the pitot tube pump with no rotating body but rotating wings, respectively, impeller blades, forcing the hydrogen stream into a rotational movement.

(5) FIG. 4 shows an alternative of the pump according to FIG. 3, whereupon the rotor extends major parts of the interior of the pump.

(6) FIG. 5. shows a design with pitot tubes, a rotating cage and through-holes within the rotating cage.

(7) FIG. 6 shows an alternative with a sealed cage.

(8) FIG. 7 shows a schematic illustration of an aircraft embodying the principles of the present invention.

(9) FIG. 8 shows a schematic illustration of a tank embodying the principles of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(10) In FIG. 1, the general principle is shown. The view is parallel to the hydrogen stream introduced into the pump, i.e., the hydrogen stream inlet 1 points perpendicularly into the paper plane. The rotor 16 (FIG. 2) accelerates the hydrogen stream in the interior of the pump, such that the liquid hydrogen 3 having a higher density compared to the gaseous hydrogen 2 is forced towards the wall of the cage. As a consequence, the hydrogen flows in circumferential direction. Hydrogen gas bubbles 6 in the liquid hydrogen 3 phase are forced to the interface 7 of the liquid hydrogen 3 and the gaseous hydrogen 2. The shown general principle represents an example which may use pitot tube 4a, 5a outlets or flush outlets as examples for non-pitot tube 4b, 5b outlets.

(11) FIG. 2 shows, in a cross-sectional view along the rotational axis, the rotating cage pitot tube pump with two pitot tube 4a, 5a outlets leading through tubes 8,9 to hydrogen stream outlets 10,11. The pitot tube 5a gathers the liquid hydrogen 3 at a position away from the rotational axis and close to the wall of the rotating cage. The rotating cage 14 assists in moving the liquid hydrogen 3 in circumferential direction. A beneficial effect associated with this exemplary pump refers to the fact that the lower pressure of the gaseous pitot tube 4a outlet assists in a re-pressurization of the tank operating as a low pressure tank. Simultaneously, the liquid hydrogen pitot 5a outlet increases pressure for the distribution to the consumer (e.g., engine). In this exemplary pump, the rotor vanes 17 have the form of tubes. There is a dynamic seal 13 between the rotating cage and inlet/outlet tubes.

(12) The pitot tube pump in FIG. 3 shows an exemplary embodiment with no rotating body but rotating wings, respectively impeller blades, forcing the hydrogen stream into a rotational movement. There is a bearing 12 associated with the hydrogen stream inlet 1 tube and the rotor vanes 17. This exemplary pump avoids the use of dynamic seals in cryogenic, i.e., liquid hydrogen atmosphere.

(13) In FIG. 4, an alternative of the pump according to FIG. 3 is shown, whereupon the rotor fills the interior of the pump. This exemplary embodiment does not allow pitot tube 4a, 5a outlets to be positioned in the interior of the pump, as the rotor vanes would collide with them. This exemplary embodiment thus makes use of non-pitot tube 4b, 5b outlets as, e.g., flush outlets. This exemplary embodiment can be put into practice if the hydrogen in the gap between the pump housing 15 and the rotor vanes 17 does not show excessive turbulence which limits the rotational movement of the hydrogen.

(14) FIG. 5 shows a pump design with pitot tubes, a rotating cage and through-holes within the rotating cage. The cage 14 is a rotating cage having through-holes 18 for passing liquid hydrogen 3 into the gap between the pump housing 15 and the cage 14. The pump housing 15 and the cage 14 together form the pump casing. The liquid hydrogen 3 in the gap forms a hydrostatic bearing. The rotor of this exemplary embodiment is formed of a slotted architecture in order to provide a maximum increase of velocity of the liquid hydrogen 3. In doing so, the pressure in the liquid hydrogen pitot 5a tube may attain a high level. The hydrogen stream inlet 1 and the hydrogen stream outlets 10, 11 are arranged in the center of the pump. There is no dynamic seal at the outside portion of the pump. The seal is between cage and outer portion of the tubes.

(15) FIG. 6 shows an alternative with a sealed cage. The rotating cage is carried by bearings and is sealed against its surrounding. The difference to the exemplary embodiment as shown in FIG. 5 is that the leakage of these seals can be tolerated. It is expected that the gaseous hydrogen 2 surrounding the rotating cage has a low viscosity such that temperature increase due to the rotation of the cage is not observed as a detrimental effect.

(16) As an alternative to the exemplary embodiments shown in FIGS. 2 to 5, multiple outlets, i.e., more than one outlet, can be accomplished in the pumps.

(17) FIG. 7 schematically shows an aircraft 62 comprising a pump 15 as described above.

(18) FIG. 8 schematically shows a tank unit 40 for an aircraft 62 comprising a reservoir 42 for hydrogen and the pump 15 as described above. By use of a centrifugal reservoir pump or a pitot tube pump, preferably by a pump according to the invention, the liquid hydrogen from the reservoir 42 can be separated from the gaseous hydrogen, whereupon the liquid hydrogen is passed to a rotational pump 46 for further passing liquid hydrogen with increased pressure to an engine 48 of the aircraft 62, or the liquid hydrogen is directly passed to an engine 48 of the aircraft 62. The reservoir 42 for hydrogen is surrounded by a multilayer insulation 44, preferably a multilayer insulation configured to provide thermal isolation between the inner part and the outer part of the reservoir 42 for hydrogen. Such multilayer insulations are known by a skilled person. The multilayer insulation enables a keeping of the heat exchange as low as possible.

(19) 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

(20) 1 Hydrogen stream inlet 2 Gaseous hydrogen 3 Liquid hydrogen 4a Gaseous hydrogen pitot tube/outlet 4b Gaseous hydrogen non-pitot tube/outlet 5a Liquid hydrogen pitot tube/outlet 5b Liquid hydrogen non-pitot tube/outlet 6 Hydrogen gas bubbles 7 Interface of the gaseous hydrogen and the liquid hydrogen 8 Final tube portion gaseous outlet 9 Final tube portion liquid outlet 10 First (gaseous) hydrogen stream outlet 11 Second (liquid) hydrogen stream outlet 12 Bearing or hydrostatic bearing 13 Dynamic seal 14 Cage 15 Pump housing 16 Canned motor 17 Rotor vanes 18 Through-holes 42 Reservoir 44 Multilayer insulation 46 Rotational pump 48 Engine 62 Aircraft