Exhaust Duct for Battery in Aircraft

Abstract

The present invention relates to an exhaust duct (10) and an aircraft (100) having such an exhaust duct (10), which protects a battery (130) from external influences and protects the systems around the battery (130) from the electrolyte emerging from the battery. The exhaust duct (10) for a battery (130) in an aircraft (100) has: a first pipe section (12) that can be connected to the battery, the first pipe section having an inlet end (14) and a first flange (16); a separate second pipe section (18), the second pipe section having a second outlet end (20) and a second flange. Additionally, the exhaust duct (10) has an inner sleeve (24) and an outer sleeve (26). The inner sleeve and the outer sleeve are made of non-conductive materials. The inner sleeve (24) is positioned outside (28, 29) the first flange (16) and the second flange (22). The outer sleeve (26) surrounds the first flange (16), the second flange (22), and the inner sleeve (24). The first flange (16) and the second flange (22) are fastened to each other such that at least the second pipe section (18) is electrically insulated by the inner sleeve (24) and the outer sleeve (26), and the combination of the inner sleeve (24) and the outer sleeve (26) is heat-resistant up to a temperature of at least 1100 °C and pressure-resistant up to a pressure of at least 8 bar, respectively, for a duration of at least 120 s.

Description

Field of the Invention

[0001] The present invention relates to an exhaust duct and an aircraft having such an exhaust duct. Background Art

[0002] Electrification in the aviation industry plays an increasingly important role. In this context, it is important that the battery meets the safety requirements for frictionless use in an aircraft.

[0003] In this context, it is particularly desirable to design the exhaust duct of the battery in such a way that it still protects the surrounding aircraft systems even in the event of a battery failure or damage. In the event of a battery failure in an aircraft, an exhaust flow with a high temperature may be generated, which needs to be safely discharged from the aircraft. For the integration of different types of batteries, many regulations (such as EASA, FAR and others) are related to ensuring the highest possible safety.

[0004] DE 20 2016 001 797 U1 discloses a transport device for lithium batteries in an aircraft (especially in a cargo hold). The transport device has a container and a cover, wherein the lithium battery is arranged in the container and the cover closes the container when transporting the lithium battery. The released electrolyte can be guided out of the aircraft through a duct. Summary of the Invention

[0005] When arranging the duct leading outwards from the aircraft, attention should be paid to ensuring sufficient safety against lightning strikes (which may damage the battery). In addition, the duct should be designed in such a way that sufficient temperature stability is achieved within the relevant regulations.

[0006] The object of the present invention is therefore to provide a device by means of which the battery is protected from external influences and the systems around the battery are protected from the escaping electrolyte.

[0007] This object is achieved by the features of the present invention. Preferred improvements are the subject of the following description.

[0008] According to a first aspect of the present invention, an exhaust duct for a battery in an aircraft is proposed. The exhaust duct has: a first pipe section connected to the battery, the first pipe section having an inlet end and a first flange; and a separate second pipe section, the second pipe section having a second outlet end and a second flange, as well as an inner sleeve and an outer sleeve. The inner sleeve and the outer sleeve are made of a non-conductive material. The inner sleeve is positioned outside the first flange and the second flange. The outer sleeve surrounds the first flange, the second flange, and the inner sleeve. The first flange and the second flange are fastened to each other such that at least the second pipe section is electrically insulated by the inner sleeve and the outer sleeve and the combination of the inner sleeve and the outer sleeve is heat-resistant up to a temperature of at least 1100 °C and pressure-resistant up to a pressure of at least 8 bar for a duration of at least 120 s, respectively.

[0009] The exhaust duct relates to a duct for transporting battery exhaust.

[0010] The first pipe section forms part of the exhaust duct, and this part only extends inside the aircraft in the installed state. The first flange is arranged at the end of the first pipe section facing away from the battery. The first flange can be implemented only in the form of a pipe end. Optionally, the first flange can also have a cantilever or other, especially outward-facing, shape features that result in an improved placement of the inner sleeve and / or the outer sleeve.

[0011] Preferably, the first pipe section is welded to the electrolyte outlet of the battery. Alternatively, the first pipe section can also be connected to the electrolyte outlet by a threaded connection. In one example, the electrolyte outlet can be formed as a flange. Another flange is provided at the second end of the first pipe section, i.e., the end facing the battery, in order to connect the first pipe section to the electrolyte outlet by a threaded connection.

[0012] The second pipe section forms another part of the exhaust duct, and this part also only extends inside the aircraft in the installed state. The second flange is arranged at the end of the second pipe section facing the first flange. The second flange can be implemented only in the form of a pipe end. Optionally, the second flange can also have a cantilever or other, especially outward-facing, shape features that result in an improved placement of the inner sleeve and / or the outer sleeve.

[0013] The term "flange" can also be referred to as a connection end. The first and second flanges respectively constitute the two pipe ends of the first and second pipe sections to be connected.

[0014] The term "inner sleeve" relates to a preferably cylindrical object having an annular cross-section. The inner diameter of the inner sleeve at least corresponds to the outer diameter of the two flanges and is preferably slightly larger in order to push the inner sleeve through the first and second flanges. The length of the inner sleeve at least corresponds to the spacing between the two pipe ends and is preferably longer in order to be able to be safely placed on the pipe ends.

[0015] The term "outer sleeve" preferably also refers to a cylindrical object having an annular cross-section. The inner diameter of the outer sleeve is greater than the inner diameter of the inner sleeve, such that the outer sleeve can be plugged into the inner sleeve located thereon through the first pipe section and the second pipe section.

[0016] The axial direction refers to the direction along the exhaust duct. The radial direction refers to the direction transverse to the exhaust duct.

[0017] It is known that the combination of the inner sleeve and the outer sleeve can achieve a heat resistance of at least 1100 °C over a predetermined period of time, even though the inner sleeve and the outer sleeve alone can only withstand lower temperatures. For example, the inner sleeve or the outer sleeve can only withstand temperatures up to approximately 200 °C. The arrangement of the two sleeves separated from each other (optionally may include an intermediate space relative to each other) results in a significantly improved heat resistance. Thus, the proposed arrangement can significantly improve the heat resistance without using a conductive material.

[0018] Similarly, the combination of the inner sleeve and the outer sleeve can improve the pressure resistance over a predetermined period of time. By using a non-conductive material, the exhaust duct is also electrically insulated and especially protected from lightning strikes. Thereby, the introduction of external current into the battery is avoided. Here, at least the second pipe section is electrically insulated from the first pipe section, such that the current caused by a lightning strike hitting the second pipe section cannot reach the first pipe section and thus cannot reach the battery and damage the battery.

[0019] According to an advantageous embodiment, the exhaust duct has two spacer holders, which are arranged, preferably welded, at the first flange or the second flange in order to space the inner sleeve and the outer sleeve from each other in the radial direction. The spacer holders are also implemented as sleeve-shaped components surrounding the respective flange at a certain distance. The outer diameter of the inner sleeve is preferably set such that the outer side of the inner sleeve abuts against the inner side of the respective spacer holder. Thereby, the inner sleeve is held in the radial direction by the spacer holder. The inner sleeve is thus located between the respective flange and the spacer holder arranged thereon. The inner sleeve and the outer sleeve are spatially separated from each other by the spacer holder. The spacer holder can also fix the inner sleeve in the axial direction.

[0020] This ensures that the first pipe section and the second pipe section are protected from the outside and are comprehensively protected at the connection position of the first and second pipe sections. The first flange and the second flange are spatially separated from each other by a spacing in the axial direction of the exhaust duct, such that current cannot be transmitted from the second pipe section to the first pipe section.

[0021] According to another advantageous embodiment, these spacer retainers are designed such that the inner sleeve extends at least along the spacing predefined by the spacer retainers. In combination with the outer sleeve located radially thereon, the exhaust duct at the connection position of the first and second flanges is heat-resistant up to at least 1100 °C and pressure-resistant up to at least 8 bar. Outside the connection position, higher values exist in terms of pressure resistance and heat resistance.

[0022] The spacer retainers preferably have an L-shaped profile. The ends of the shorter legs of the L-shape are respectively welded to the outer side of the corresponding pipe section or to the flange involved. The longer legs of the spacer retainers can be straight or slightly curved.

[0023] The length of the inner sleeve is designed, for example, such that the inner sleeve is held axially by the inner side of the shorter leg of each spacer retainer. This ensures that the inner sleeve is firmly positioned axially.

[0024] In another conceivable embodiment, the inner sleeve directly provides the spacing between the first and second flanges. In this instance, the inner sleeve has a radial protrusion in the middle part, which has a known width along the axial direction in order to create an insulating spacing between the first and second flanges. The radial protrusion has a radial extension dimension that at least corresponds to the wall thickness of the first and second flanges.

[0025] The spacer retainers preferably also have additional heat-resistant material at least in sections. Thereby, the heat resistance can be further increased, that is, in the temperature range of at least 1100 °C. The spacer retainers can be realized with heat-resistant material approximately in the middle region. The spacer retainers can also consist entirely of heat-resistant material. In addition, the exhaust duct can be supplemented by a ring formed of heat-resistant material, which is placed on the inner sleeve between two spacer retainers.

[0026] According to a preferred embodiment, the outer sleeve is sized to enclose the spacer retainers, the first flange, and the second flange. The non-conductive material is preferably elastic such that it can be pushed onto the spacer retainers.

[0027] Preferably, the non-conductive material is silicone. It has been shown that silicone best meets the requirements in terms of heat resistance, pressure resistance, and electrical conductivity.

[0028] According to one embodiment, the outer sleeve is form-fittingly and / or force-fittingly fastened to the first and second flanges in order to thereby be connected to the first pipe section and the second pipe section. In another instance, the outer sleeve is fastened at the first and second pipe sections, that is, the outer sleeve is sized such that the outer sleeve is arranged in the axial direction of the exhaust duct through the first and second flanges. The length of the outer sleeve in the axial direction can be longer than that of the inner sleeve.

[0029] The outer sleeve is preferably connected to the first and second flanges in a form-fitting manner so as to connect the first pipe section and the second pipe section to each other.

[0030] According to another embodiment, the exhaust duct further has at least two pipe clamps for fastening the outer sleeve to the first pipe section and the second pipe section. Here, one pipe clamp is arranged at each of the first flange and the second flange for fastening the outer sleeve to the first flange and the second flange. In one example, two pipe clamps are arranged at each of the first flange and the second flange. In another example, the outer sleeve is adhesively bonded to the first and second flanges. It is also conceivable that the outer sleeve is sized to be longer and the outer sleeve is respectively arranged at the first pipe section and the second pipe section for fastening the outer sleeve to the first pipe section and the second pipe section respectively. Of course, this variant can be employed with the use of spacer elements. The outer sleeve is then placed flush on the spacer elements.

[0031] According to a second aspect of the present invention, an aircraft is proposed. The aircraft has a fuselage which has a fuselage skin and a bursting disc arranged therein. Furthermore, the aircraft has a battery and an exhaust duct. The inlet end of the first pipe section of the exhaust duct is connected to the battery and the outlet end is connected to the inner side of the bursting disc. The bursting disc is formed to burst at a predetermined pressure within the exhaust duct so as to discharge the exhaust from the aircraft.

[0032] The bursting disc bursts at the latest at a pressure of 2.5 bar. Thereby, the exhaust of the battery can escape from the aircraft starting from a certain pressure. This is usually the case when the battery is damaged. The exhaust duct of the present invention is designed to discharge the exhaust flow generated in this case and having a relatively high pressure from the aircraft such that the aircraft and the surrounding systems are not affected in their operation.

[0033] According to one embodiment, the battery is a lithium-ion battery.

[0034] It should be noted that the features of the embodiments of the system are also applicable to the embodiments of the cabin section and the embodiments of the vehicle, and vice versa. Additionally, the features can also be freely combined with each other even if this is not explicitly mentioned in these features.

[0035] These and other aspects of the present invention can be seen with reference to and in connection with the following embodiments. Description of the Drawings

[0036] The embodiments of the present invention will be described below with reference to the drawings. Shown in the drawings are:

[0037] Figure 1 A schematic cross-sectional view showing an embodiment of the exhaust duct and such a battery (as a connection between the battery and the fuselage skin);

[0038] Figure 2 Another schematic cross-sectional view of an exhaust duct having a spacing retainer according to an embodiment of the present invention is shown;

[0039] Figure 3 A schematic perspective view of the exhaust duct is shown;

[0040] Figure 4 A schematic view of an aircraft having the exhaust duct of the present invention is shown. Detailed Description

[0041] Figure 1 An exhaust duct 10 for a battery 130 in an aircraft 100 is shown. The exhaust duct 10 has: a first pipe section 12 capable of being connected to the battery 130, the first pipe section having an inlet end 14 and a first flange 16; a separate second pipe section 18 having a second outlet end 20 and a second flange 22; and an inner sleeve 24 and an outer sleeve 26. The inner sleeve 24 and the outer sleeve 26 are made of non-conductive materials. The inner sleeve 24 is positioned outside 28, 29 of the first flange 16 and the second flange 22. The outer sleeve 26 surrounds the first flange 16, the second flange 22, and the inner sleeve 24. The first flange 16 and the second flange 22 are fastened to each other such that at least the second pipe section 18 is electrically insulated by the inner sleeve 24 and the outer sleeve 26 and at the same time is heat-resistant up to a temperature of at least 1100 °C and pressure-resistant up to a pressure of at least 8 bar, respectively, for a duration of at least 120 s.

[0042] In addition, Figure 1 An exemplary section of the battery 130 (where the inlet end 14 of the first pipe section 12 is fastened to the battery) and the fuselage skin 110 is shown, which section has a rupture disk 120 to which the outlet end 20 of the second pipe section 18 is connected.

[0043] The inner sleeve 24 is arranged at the first pipe section 12 and the second pipe section 18 (see the dashed line). The inner sleeve 24 spans the spacing between the first and second flanges 16, 22 here. It is possible that stoppers (not shown) are provided on the outer sides of the first and second pipe sections 12, 18 to position the inner sleeve in the desired position. By these stoppers, it is ensured that the inner sleeve 24 spans or fills the spacing between the first and second flanges 16, 22. The outer sleeve 26 serves as an additional connection between the first and second pipe sections 12, 18.

[0044] Figure 2Another embodiment of the exhaust duct 10 with two spacing retainers 30 is shown. The spacing retainers 30 are welded at the first flange 16 and the second flange 22 so as to space the inner sleeve 24 and the outer sleeve 26 radially from each other at these two flanges 16 and 22. The spacing retainers 30 preferably have one or more L-shaped retainers. The shorter legs are welded to the outer sides of the first flange 16 or the second flange 22 respectively. The longer legs of the spacing retainers are straight or slightly curved.

[0045] In the example shown here, the spacing retainer 30 is designed in such a way that the inner sleeve 24 spans the spacing predefined by the spacing retainer 30 between the first and second flanges 16, 22.

[0046] Furthermore, the spacing retainer also has additional heat-resistant material 31 at least in the section 31. According to the embodiment shown here, the heat-resistant material 31 extends in such a way that the heat-resistant material 31 additionally covers the spacing between the flanges 16 and 22. This heat-resistant material can thus be a ring made of heat-resistant material placed on the inner sleeve 24.

[0047] In another embodiment not shown here, the spacing retainer 30 consists of heat-resistant material. In another embodiment not shown here, the spacing retainer is not made of heat-resistant material.

[0048] According to an example not shown here, the outer sleeve 26 is sized such that the first flange 16, the second flange 22 and the spacing retainer 30 are enclosed. This non-conductive material is silicone for example.

[0049] In one example, the outer sleeve 26 is connected to the first and second flanges 16, 22 in a form-fitting and / or force-fitting manner so as to be connected to the first pipe section 12 and the second pipe section 18 thereby. According to the example shown here, the exhaust duct 10 also has at least two pipe clamps 32, 33 so as to fasten the outer sleeve 26 to the first pipe section 12 and the second pipe section 18 or to the spacing retainer 30 located thereon. In the example shown, the outer sleeve 26 is fixed with two pipe clamps 32.

[0050] Figure 3 The exhaust duct 10 is shown in a perspective view. The installation process of the inner sleeve 24 and the outer sleeve 26 in or on the first and second pipe sections 12, 18 is explained here. The inner sleeve 24 is partially inserted into the first flange 16 such that a part also projects beyond the first flange 16. The inner sleeve thus lies between the first flange 16 and the spacing retainer 30 located thereon.

[0051] Preferably, the portion of the inner sleeve 24 inserted onto the first flange 16 is similar in length to the portion of the inner sleeve 24 extending beyond the first flange 16. Then, the outer sleeve 26 is directly inserted onto the second pipe section 18, directly inserted onto the spacer 30, and pushed onto the spacer 30 such that the outer sleeve 26 no longer extends beyond the second sleeve 18. In the next step, the inner sleeve 24 at the first flange 16 and the second flange 18 is arranged such that the inner sleeve 24 is inserted into the annular gap between the second flange 18 and the spacer 30 located thereon. In another step not shown in detail, the outer sleeve 26 is finally pushed through the assembly formed by the spacer 30 and the inner sleeve 24. Here, the outer sleeve 26 is symmetrically arranged at the first and second pipe sections 12, 18 with respect to the center line 40 in the manner shown in Figure 1 or Figure 2 . Then, as a final step, this assembly is fastened.

[0052] Figure 4 FIG. 100 shows an aircraft 100. The aircraft 100 has a fuselage 110 which has a fuselage skin and a bursting disc 120 arranged therein. In addition, the aircraft 100 has a battery 130 and an exhaust duct 10. The inlet end 14 (see Figure 1 ) of the first pipe section 12 (see Figure 1 ) of the exhaust duct 10 is connected to the battery 130 and the outlet end 20 (see Figure 1 ) is connected to the inner side of the bursting disc 122 (see Figure 1 ). The bursting disc 120 is formed to burst at a predetermined pressure within the exhaust duct in order to discharge the exhaust from the aircraft.

[0053] The position of the bursting disc 120 in the fuselage 110 depends on the position of the battery 130 in the aircraft. The side of the second pipe section 18 facing the bursting disc 120 is welded to the inner side of the bursting disc 120.

[0054] The above embodiments can be combined in different ways.

[0055] Supplementary, it can be noted that "including" does not exclude other elements or steps, and "a / an" does not exclude a plurality. Furthermore, it can be noted that features already described with reference to one of the above embodiments can also be used in combination with other features or steps of other embodiments described above. The reference numerals in this document should not be regarded as limiting.

Claims

1. An exhaust duct (10) for a battery (130) in an aircraft (100), the exhaust duct having: - a battery (130), - a first pipe section (12) connected to the battery (130), the first pipe section having an inlet end (14) and a first flange (16), - a separate second pipe section (18), the second pipe section having a second outlet end (20) and a second flange (22); - an inner sleeve (24) and an outer sleeve (26), wherein the inner sleeve and the outer sleeve are made of non-conductive material; wherein the inner sleeve (24) is positioned outside (28, 29) the first flange (16) and the second flange (22); wherein the outer sleeve (26) surrounds the first flange (16), the second flange (22) and the inner sleeve (24); wherein the first flange (16) and the second flange (22) are spatially separated from each other by a spacing in the axial direction of the exhaust duct (10) and are fastened to each other such that at least the second pipe section (18) is electrically insulated by the inner sleeve (24) and the outer sleeve (26), such that current cannot be transmitted from the second pipe section (18) to the first pipe section (12) and such that current induced by a lightning strike hitting the second pipe section (18) cannot reach the first pipe section (12) and thus cannot reach the battery (130), and the combination of the inner sleeve (24) and the outer sleeve (26) is heat-resistant up to a temperature of at least 1100 °C and pressure-resistant up to a pressure of at least 8 bar, respectively for a duration of at least 120 s, and wherein spacer holders (30) are respectively arranged at the first flange (16) and the second flange (22) so as to space the inner sleeve (24) and the outer sleeve (26) from each other in the radial direction.

2. The exhaust duct (10) according to claim 1, wherein the spacer holders (30) are sized such that the inner sleeve (24) fills the spacing predefined by the spacer holders (30).

3. The exhaust duct (10) according to claim 1 or 2, wherein the spacer holders (30) also have additional heat-resistant material at least over the spacing defined by the spacer holders (30).

4. The exhaust duct (10) according to claim 1 or 2, wherein the outer sleeve (26) is designed to surround the first flange, the second flange and the spacer holders (30).

5. The exhaust duct (10) according to claim 1 or 2, wherein the non-conductive material is silicone.

6. The exhaust duct (10) according to claim 1 or 2, wherein the outer sleeve (26) is connected to the first and second flanges (16, 22) in a form-fitting and / or force-fitting manner so as to be connected to the first pipe section (12) and the second pipe section (18) thereby.

7. The exhaust duct (10) according to claim 1 or 2, wherein the exhaust duct (10) further has at least two pipe clamps (32, 33) so as to fasten the outer sleeve (26) to the first pipe section (12) and the second pipe section (18).

8. An aircraft (100) having: - A fuselage (110) having a fuselage skin and a rupture disk (120) arranged therein; - An exhaust duct (10) according to any one of claims 1 to 7; wherein the inlet end (14) is connected to the battery (130) and the outlet end (20) is connected to the inside of the rupture disk (122), and wherein the rupture disk (120) is formed to rupture at a predetermined pressure within the exhaust duct (10) so as to discharge the exhaust from the aircraft.

9. The aircraft according to claim 8, wherein the battery (130) is a lithium-ion battery.

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