ENERGY-GENERATING GONDOLA FOR AN AIRSHIP

Description

FIELD OF INVENTION

[0001] The field of the invention is that of rigid structure electrically propelled airships, designed for the transport of heavy loads, and more particularly that of the mechanical structure of electric power generation nacelles equipping these airships. STATE OF THE ART

[0002] For supplying electrical power to electrically propelled airships, several technological avenues can be considered, including the use of a turbogenerator or a fuel cell.

[0003] For either of these technological approaches to providing an onboard electrical power generation system, the question arises of the airship's safety in the event of a power generation system failure. In particular, when using a turbogenerator, a mechanical failure of the turbine shaft could lead to the high-speed projection of mechanical parts that could strike the airship's main body and endanger it. The risk of fire caused by the operation of a turbogenerator in the event of a fuel leak must also be considered. Similarly, when using a fuel cell, there are technological risks due to the presence of hydrogen gas.

[0004] For these reasons, it is generally planned to locate these electrical power generation systems—which can be very powerful—outside the main body of the airship. This limits the risk of a fire spreading from a turbine generator or of damage to the airship's mechanical structure due to flying mechanical parts. Airship designs already exist that incorporate nacelles housing electrical power systems and are mechanically connected to the airship's body; see WO 2020 / 159402 A1.

[0005] However, the construction of such nacelles poses technical problems when high levels of electrical power are targeted, both for reasons of mass optimization and for the safety of the mechanical link between these nacelles and the body of the airship.

[0006] One objective of the present invention is to solve these problems by proposing a new electrical generation nacelle structure implemented in an electrically propelled airship. DESCRIPTION OF THE INVENTION

[0007] This objective is achieved with a gondola according to claim 1.

[0008] The stay bars or cables may, for example, include a front connecting bar or cable, a rear connecting bar or cable, and a top connecting bar or cable.

[0009] The gondola's mechanical structure can, for example, be constructed as a truss of composite beams / tubes. However, many other materials and techniques can also be used for this mechanical structure, provided they comply with fire safety standards and zonal classifications. Riveted beams, frames, or skins are all possibilities. A molded gondola structure is another option. Furthermore, thermal protection can be incorporated into parts of the gondola's mechanical structure that present a risk of fire exposure.

[0010] A platform may also include winch means for controlling the descent of an electrical power generation unit, said winch means being fixed to the upper part of the platform structure. Ground support equipment (GSE) may also be used for the placement of the electrical power generation units.

[0011] At least one streamlined nacelle may further include an envelope comprising a rigid part which may further include openings for at least one ventilation inlet and at least one ventilation outlet of the nacelle.

[0012] The gondola envelope may further include a semi-rigid part disposed between the main body of the airship and the rigid part, this semi-rigid part being able to include an exhaust outlet for the cooling of an electrical energy storage system and at least one opening for the passage of a bar or cable acting as a stay.

[0013] The gondola envelope may further include a flexible part extending from the rigid part to a distal end of the gondola which is equipped with a positioning light device.

[0014] In a first configuration, the electrical power generation unit(s) may include at least one turbogenerator. In this configuration, the rigid part of the nacelle may also include at least one opening for the exhaust gas outlet of this turbogenerator.

[0015] In a second configuration, the electrical power generation unit(s) may include at least one fuel cell system.

[0016] In another embodiment of a gondola equipping an airship according to the invention, at least one of the streamlined gondolas may further comprise a flexible material envelope stretched over a plurality of hoops surrounding said gondola.

[0017] According to another aspect of the invention, an airship is proposed according to claim 12. BRIEF DESCRIPTION OF THE FIGURES

[0018] There figure 1 This represents a side view of an example of an airship equipped with two electric power generation nacelles. figure 2 illustrates an example of the mechanical coupling of a gondola to the rigid structure of an airship according to the invention. figure 3 illustrates an example of the construction of an enclosure for an electrical power generation nacelle according to the invention. figure 4 illustrates a mechanical structure of an electrical power generation nacelle according to the invention. figure 5 illustrates the placement of the gondola's mechanical structure relative to that of the airship. DETAILED DESCRIPTION

[0019] With reference to the figure 1 , a rigid-structure airship D comprises a set of propulsion units P powered by electrical energy from electrical power generation systems integrated into two external fin-shaped nacelles 1 (only one of which is shown on the figure 1 ).

[0020] A fin-shaped nacelle 1 comprises a mechanical structure 300 made from a lattice of composite material beams and covered with a hull or fairing skin 10. This mechanical structure 300 includes a connecting part 30 between an upper part 31 intended to carry two turbogenerators 84.1,84.2 and a lower part 9.

[0021] The upper part 31 of the mechanical structure is connected to a frame 4 of the main body of the airship via a mechanical interface 3 and three cables 7,70,71.

[0022] The nacelle 1 incorporates two turbogenerator sets 84.1,84.2 mounted suspended from the upper part 31 of the mechanical structure of the nacelle 1, a storage battery system 85, and a floor 5.

[0023] This floor 5 includes an access route 50 from inside the airship D into the gondola 1, and a floor section 52 surrounding the two turbogenerators 84.1, 84.2. Recessed sections 51 are provided in the floor 5 to allow the turbogenerators to be removed by means of winches provided on the upper part 31 of the mechanical structure. It should be noted that the present invention can equally be implemented in a gondola that does not have a floor.

[0024] The two turbogenerators 84.1,84.2 are connected at output to an energy conversion system 85 to a storage battery system 92 which are connected to an electrical distribution system within the airship.

[0025] This nacelle is also equipped with a thermal management system designed to cool the turbogenerators and ventilate the containment structures housing these turbogenerators, as well as cool the energy conversion systems and storage batteries. The nacelle's skin must therefore accommodate all the interfaces between the nacelle's internal systems and the outside, including air intake ducts, gas exhaust ducts, and drains.

[0026] In a practical example of how to build a gondola, illustrated by the figure 3 , the gondola envelope 200 comprises a semi-rigid skin part 110 disposed against the mechanical structure 4 of the airship, a rigid skin part 120 substantially covering the turbogenerators and a flexible skin part 130 covering the fin-shaped distal end of the gondola, this distal end being provided with a position light device 131.

[0027] The rigid skin part 120, made for example from a composite material, has openings 121 to receive air inlet ducts for the ventilation of the nacelle, openings 123 to receive exhaust ducts for the combustion gases of the turbogenerators, and openings 124 to receive ventilation outlet grilles for the nacelle.

[0028] The semi-rigid skin part 110, made for example of a polymer-type material for netting, includes an evacuation grid 111 for cooling a battery system integrated into the gondola, and openings 117, 118, 119 provided to allow passage of the guy wires 7, 70, 71 linking the mechanical structure of the gondola to that of the airship.

[0029] In a particular example of the realization of a gondola's mechanical structure, illustrated by the figures 5and 6, the mechanical structure 300, made by lattice assembly of tubes in composite material, includes a connecting part 30 fixed at its two ends respectively upper and lower by respectively a mechanical connecting interface 3 of the "fail safe" type and a joint 34 to longitudinal structural lattice beams 44,42 whose ends are connected to peripheral lattice beams 41,44 in the structure of the main body of the airship.

[0030] This connecting section 30 is rigidly attached on one side to an upper section 31 designed to support two turbogenerators and their auxiliary equipment, and on the other side to a lower section 9 intended to receive a floor 5 allowing an operator to access the turbogenerators from inside the airship for maintenance purposes. Mechanical structural components 6 are arranged between the upper section 31 and the lower section to stiffen the mechanical structure 300 of the nacelle. The mechanical structure is further connected to the mechanical structure 4 of the airship's main body by means of three cables or rods 7, 70, 71 acting as stays, each of these cables or rods having a first lower end fixed at a point on the upper section of the nacelle structure 300 and a second upper end fixed at a point on the mechanical structure 4 of the airship's main body.

[0031] For example, we can provide for a first front link cable 7 between a point on the upper part of the mechanical structure of the gondola 300 and a point on the rigid structure 4 of the airship located in front of the gondola, a second upper link cable 70 between a point on the upper part of the mechanical structure of the gondola and a point located on an upper part of the rigid structure of the airship overhanging the gondola, and a third rear link cable 71 between a point on the upper part of the mechanical structure of the gondola and a point on the rigid structure of the airship located behind the gondola.

[0032] In the event of a violent downward force exerted on the gondola, leading to the rupture of the main retaining cable or debris severing this main cable, the "fail-safe" interface 3 performs its function and mechanically switches to "safe" mode by establishing a standby secondary mechanical connection, thus preventing damage to the airship's mechanical structure. The gondola is then held by the stay cables 7, 70, 71, preventing its loss.

[0033] The "fail safe" link interface 3 can for example be made by a bar with a waiting clevis, a mechanical piston 3B and a lightly loaded cable 3A.

[0034] Of course, other embodiments of a mechanical structure for a gondola according to the invention can be considered without departing from the scope of the present invention. In particular, other envelope geometries than the one just described can be considered.

Claims

1. A nacelle (1, 200) for an airship (D) comprising a main body, having a rigid structure (4) surrounding a plurality of containers of a lighter-than-air gas and electric propulsion units, said nacelle (1, 200) comprising at least one electric-power-generating unit (84.1, 84.2) for powering said electric propulsion units, said nacelle (1, 200) being faired and comprising a mechanical structure (300) intended to be connected to the rigid structure (4) of the main body, characterized in that said nacelle (1, 200) comprises: (i) a joint interface (34) of a specific point of a lower part of said mechanical structure relative to the rigid structure, (ii) a "fail safe" interface (3) configured to be arranged between a point of an upper part of said mechanical structure and said rigid structure, intended to maintain a secondary standby mechanical connection beyond a predetermined upper tensile limit, and (iii) at least a rod or a cable (7, 70, 71) functioning as a traction stay between a first point of attachment on the rigid structure (4) of the main body and a second point of attachment on the mechanical structure (300).

2. The nacelle according to the preceding claim, wherein the stay rods or stay cables comprise a front connection rod or cable, a rear connection rod or cable and a top connection rod or cable.

3. The nacelle according to either of the preceding claims, further comprising a shroud (200) having a rigid part (120).

4. The nacelle according to the preceding claim, wherein the rigid part (120) comprises openings for at least one ventilation inlet (121) and at least one ventilation outlet (124) of the nacelle (1).

5. The nacelle according to the preceding claim, wherein the shroud (200) further comprises a semi-rigid part (110) intended to be arranged between the main body of the airship and the rigid part (120).

6. The nacelle according to the preceding claim, wherein the semi-rigid part (110) comprises a discharge outlet (111) for cooling an electrical energy storage system on board the nacelle (1).

7. The nacelle according to either of the two preceding claims, wherein the semi-rigid part (110) further comprises at least one opening (117, 118, 119) for the passage of a rod or of a cable (7, 70, 71) functioning as a stay.

8. The nacelle according to any of claims 3 to 7, characterized in that the shroud (200) further comprises a flexible part (130) extending from the rigid part (120) toward a distal end of said nacelle (200).

9. The nacelle according to any of the preceding claims, wherein the electric-power-generating unit or units (84.1, 84.2) comprise at least one turbogenerator.

10. The nacelle according to one of claims 3 or 4 and claim 9, wherein the rigid part (120) further comprises at least one opening (123) for the outlet of exhaust gases of the at least one turbogenerator.

11. The nacelle according to any of the preceding claims, wherein the electric-power-generating unit or units comprise at least one fuel cell system.

12. An airship comprising a main body having a rigid structure (4) surrounding a plurality of containers of a lighter-than-air gas, a plurality of propulsion units (P) mechanically connected to said rigid structure (4) and each comprising one or more electric motors for driving a pusher propeller, characterized in that it comprises two nacelles according to any of the preceding claims arranged symmetrically on either side of the main body, the electric-power-generating units being provided for powering said electric motors.

13. The airship according to the preceding claim, wherein at least one of the nacelles further comprises a shroud of flexible material stretched over a plurality of hoops surrounding said nacelle.