Aircraft with a refueling port

Abstract

The invention relates to an aircraft with a refueling port which is in a fluid-technical connection with a tank arranged in the aircraft, wherein the refueling port is arranged in a fuselage (1) of the aircraft, and the refueling port is formed by a connecting part (3) held on the fuselage (1), which has a connection (5) for a coupling piece oriented with respect to a horizontal plane (H) of the aircraft at an angle (D) of greater than 0 degrees but less than 90 degrees from above.

Description

[0001] The present invention relates to an aircraft with a refueling port having the features of the preamble of claim 1.

[0002] Aircraft powered by kerosene usually have their tanks located in the wings, with the refueling ports on the underside of the wings, allowing the aircraft to be refueled from below using a tanker truck and a hose.

[0003] The use of cryogenic fuels, such as liquid hydrogen, presents additional challenges. While the energy density of liquid hydrogen per unit mass is higher than that of kerosene, its energy density per unit volume is four times lower. To compensate for this lower volumetric energy density, hydrogen is stored and refueled in liquid form in aviation, where volume is a critical factor. This liquid state is achieved at a temperature of -253 °C, which corresponds to the boiling point of hydrogen.

[0004] To cool the cryogenic fuel to this low temperature in an energy-efficient manner, a spherical tank would be the ideal shape. However, a spherical tank is not practical in terms of the overall wing architecture, as it would poorly utilize the available space within the wing, or necessitate a correspondingly small tank. Therefore, other tank shapes and types are required, with the ratio of the external surface area to the tank volume being as small as possible for energy-efficient cooling. For example, cylindrical tanks with a circular cross-section are suitable.

[0005] Furthermore, refueling the aircraft with cryogenic fuel, such as hydrogen, requires appropriate insulation of the refueling lines and interfaces. For this purpose, an LH2 coupling has proven effective, featuring a specifically designed insulation concept with various O-rings and thus being specifically designed for a pressure line for conveying a cryogenic liquid.

[0006] Against this background, the invention is based on the objective of providing an aircraft with a refueling port which is designed for improved refueling with a cryogenic fuel.

[0007] To solve the problem, an aircraft with the features of claim 1 is proposed. Further preferred developments can be found in the dependent claims, the figures, and the accompanying description.

[0008] According to the basic concept of the invention, it is proposed that the refueling port be arranged in the fuselage of the aircraft and that the refueling port be formed by a connector held on the fuselage. This connector has a connection for a coupling piece oriented at an angle A greater than 0 degrees but less than 90 degrees from above, relative to a horizontal plane of the aircraft. The orientation of the connection corresponds to the insertion direction of the coupling piece. The coupling piece is thus attached from above at the appropriate angle to create the flow connection for refueling the aircraft. The proposed solution allows contact of the refueling port from above, thereby simplifying the use of an LH2 coupling for refueling with cryogenic propellants. The horizontal plane of the aircraft is the horizontally oriented plane through the fuselage when the aircraft is on the ground.

[0009] It is further proposed that the tank be located in the fuselage. The proposed solution has the advantage that the refueling port located on the fuselage allows the tank itself to be positioned within the fuselage without increasing the number of lines running between the refueling port and the tank. Since the fuselage has significantly larger cavities than the wings, larger cylindrical tanks with a circular cross-section can be used than those in the wings. Overall, this allows for a larger tank with a circular cross-section without fundamentally altering the aircraft's architecture.

[0010] It is further proposed that the connecting piece protrude into the fuselage. This deliberately leaves the fuselage's external geometry unchanged. For refueling, the coupling piece is essentially inserted into the fuselage or its external geometry via a corresponding cutout in the fuselage's external geometry.

[0011] It is further proposed that the connecting part be plate-shaped and fixed to the aircraft fuselage by a first edge section. The plate-shaped connecting part thus itself forms a stop for the coupling piece. The connecting part carries the connector and holds it in a predetermined position for contact with the coupling piece. To ensure that the connecting part itself is fixed in position, it is fixed to the fuselage by a first edge section.

[0012] It is further proposed that a retaining plate be provided, which is connected to the fuselage at a first edge section and to a second edge section of the connecting part at a second edge section. The connecting part and the retaining plate thus combine to form a triangular composite in cross-section, with the connecting part forming one wall and the retaining plate the other wall of the composite. If the connecting part projects into the fuselage of the aircraft, the triangular composite simultaneously forms a triangular cavity on the outer geometry of the fuselage, into which the coupling piece for refueling the aircraft can be inserted.

[0013] It is further proposed that the plate-shaped connecting part and the retaining plate form an angle of 90 degrees to each other in the direction of the outside of the hull.

[0014] The angle between the connecting part and the fuselage is preferably larger than the opposite angle between the holding part and the fuselage.

[0015] The invention is explained below with reference to a preferred embodiment and the accompanying figures. Fig. 1 a cross-section of a section of the fuselage with a refueling port, and Fig. 2. An oblique view of the refueling port from the inside of the fuselage.

[0016] In the Fig. Figure 1 shows a section of the fuselage 1 of an aircraft. The fuselage 1 is the central, usually tubular, middle section of the aircraft, oriented in the direction of flight. It serves to house passenger seats, luggage, cargo, the cockpit, and / or the aircraft's central technical systems in general, and therefore has a correspondingly large cavity whose shape is adapted to its function. The wings of the aircraft, or in the case of a single-wing aircraft, the wings themselves, are attached to the fuselage 1. These wings generate lift and are thus aerodynamically shaped.

[0017] The hull 1 contains a tank (not shown) which, for the purpose of energy-optimized cooling with the largest possible volume, is cylindrical with a circular cross-section and serves to hold liquid hydrogen, i.e., a cryogenic fuel, at a temperature of less than minus 253 °C.

[0018] A refueling port is provided on the underside of the fuselage 1. This port is formed by a connector 3 with a centrally located port 5 for connecting an LH2 coupling piece that can be inserted from the outside. The connector 3 is attached to the inside of the fuselage 1 in the area of ​​an edge of a cutout 16 in the fuselage 1, for example, by means of a weld or rivet connection via a first edge section 10. A retaining plate 2 is also provided, which is likewise attached to the opposite edge of the cutout 16 on the inside of the fuselage 1 via a weld or rivet connection via a first edge section 11. The cutout 16 in the fuselage 1 is rectangular, and the connector 3 and the retaining plate 2 are attached to two opposite edges of the cutout 16.

[0019] The connecting part 3 and the retaining plate 2 are connected to each other at an angle C of 90 degrees (i.e., at a right angle) via their second edge sections 12 and 13, which are arranged at opposite ends of the connecting part 3 and the retaining plate 2 with respect to the first edge sections 10 and 11. The connecting part 3 is attached to the edge of the cutout 16 with its first edge section 10 such that the connecting part 3 is aligned at an angle A to an imaginary extension of the fuselage 1 within the cutout 16. The retaining plate 2 is attached to the edge of the cutout 16 with its first edge section 11 such that the retaining plate 2 is aligned at an angle B to an imaginary extension of the fuselage 1 within the cutout.

[0020] The angle A between the connecting part 3 and the imaginary extension of the fuselage 1 in the cutout 16 is larger than the opposite angle B between the retaining plate 2 and the imaginary extension of the fuselage 1 in the cutout 16. Furthermore, the retaining plate 2 has a greater length from the first edge section 11 to the second edge section 13 than the connecting part 3 has from the first edge section 10 to the second edge section 12.

[0021] This geometry results in a insertion direction for the coupling piece at connection 5 in the X-direction, in this case orthogonal to the plate-shaped connection part 3, which is arranged at an angle D between 0 degrees and 90 degrees to a horizontal plane H of the aircraft in a ground-mounted configuration. This means that the coupling piece of the LH2 coupling is inserted obliquely from above into the refueling port located on the underside of the fuselage 1, thus reducing the probability of embrittlement of the O-rings in the LH2 coupling piece and the associated probability of failure.

[0022] In the Fig.The same refueling port on the fuselage 1 is visible from the perspective of the aircraft's interior. The mounting plate 2 and the connecting part 3 are further stiffened and connected by two reinforcing ribs 7 and 8. Furthermore, the assembly of the connecting part 3 and the mounting plate 2 is completed by two lateral cover plates 14 and 15, forming a closed assembly facing the aircraft's interior. This results in a cutout 16 in the form of a recess in the outer geometry of the fuselage 1, which can be closed by a flap to create a closed cavity 4.

[0023] The connection 5 of the connecting part 3 is designed in the direction of the interior of the aircraft in the form of a short cylindrical extension, on which a pipe section 7 of a tank not shown, located in the interior, is attached by means of a pipe clamp 6.

[0024] Connection 3 is specifically designed here as a refueling port for a coupling piece of an LH2 coupling for cryogenic liquid hydrogen via connection 5. If refueling with a different cryogenic fuel is intended, connection 5 can also be specifically designed for this purpose. Furthermore, other service connections for power supply, water drainage, and / or water supply, and the like, can also be provided on connection 3. Connection 5 can also itself be formed by a coupling half, e.g., of an LH2 coupling.

[0025] The refueling port is located in the lower half of the fuselage 1, whereby the provided connection part 3 and the orientation of the connection 5 thereon still allow the coupling piece to be inserted from above. The orientation of the coupling piece's feed direction can be individually configured by the orientation of the connection part 3, whereby the feed direction is decoupled from the orientation of the fuselage 1 and the local fuselage shape. The solution according to the invention enables the aircraft to be refueled in a direction optimized for service and handling.

[0026] Furthermore, the right-angled connection of the retaining plate 2 and the connecting part 3 at angle C does not restrict the operating range for supplying the coupling piece and contacting the coupling piece with the connection 5, and the enlargement of the cutout 16 in the body 1 can be limited to a minimum. An angle C greater than 90 degrees would not increase the operating range but would only increase the cutout 16 in the body 1, whereas an angle C less than 90 degrees would reduce the cutout 16 but would also reduce the operating range for accessing the coupling piece. Therefore, the proposed angle C of 90 degrees at the connection of the second edge sections 12 and 13 of the connecting part 3 and the retaining plate 2 is optimal with regard to fulfilling both criteria. 1 Hull 2 Mounting plate 3 Connection part 4 cavities 5 connection 6 clamping element 7 pipe sections 8 stiffening rib 9 stiffening rib 10 First marginal section 11 First marginal section 12 Second marginal section 13 Second marginal section 14 Cover plate 15 Cover plate 16 Excerpt Angles A, B, C, D H Horizontal plane X Connection direction

Claims

[1] Aircraft with a refueling port which is in a fluid-flow connection with a tank located in the aircraft, characterized by , that -the refueling port is located in a fuselage (1) of the aircraft, and -the refueling port is formed by a connection part (3) held on the fuselage (1), which has a connection (5) for a coupling piece oriented at an angle (D) of greater than 0 degrees but less than 90 degrees from above in relation to a horizontal plane (H) of the aircraft. [2] Aircraft according to claim 1, characterized by , that -the tank is arranged in the hull (1). [3] Aircraft according to one of claims 1 or 2, characterized by , that -the connecting part (3) protrudes into the hull (1). [4] Aircraft according to any one of claims 1 to 3, characterized by , that -the connecting part (3) is plate-shaped, and -the connecting part (3) is fixed to the fuselage (1) of the aircraft with a first edge section (10). [5] Aircraft according to claim 4, characterized by , that -a retaining plate (2) is provided which -is connected to the hull (1) with a first edge section (11), and -is connected to a second edge section (13) with a second edge section (12) of the connecting part (3). [6] Aircraft according to claim 5, characterized by , that -the plate-shaped connecting part (3) and the retaining plate (2) form an angle (C) of 90 degrees to each other in the direction of the outside of the hull (1). [7] Aircraft according to one of claims 5 or 6, characterized by , that -the angle (A) between the connecting part (3) and the hull (1) is greater than the opposite angle (B) between the holding part (2) and the hull (1).

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