Aircraft

Abstract

To provide an air vehicle which enables improvement of occupants' safety.SOLUTION: An air vehicle includes a fuel battery system. The air vehicle has a fuselage part including a passenger compartment. The fuel battery system includes at least one fuel gas tank. A lower end of the fuel gas tank is located below a lower end of the fuselage part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This application relates to air vehicles. [Background technology]

[0002] In recent years, the development of aircraft equipped with fuel cell systems has been progressing. Since the fuel gas tank included in the fuel cell system is a relatively large component, various considerations have been made regarding the location of the fuel gas tank.

[0003] For example, Patent Document 1 discloses that a fuel gas tank is arranged to form part of the skin of the aircraft. Patent Document 2 discloses that a water tank for fuel reforming is provided either under the floor of the aircraft, in the ceiling, or in the center wing. Patent Document 3 discloses that a fuel gas tank is housed in the air steer envelope. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2011-506186 [Patent Document 2] JP 2003-176729 A [Patent Document 3] Special Publication No. 2015-530951 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when an aircraft makes an emergency landing or crashes, a large shock is generated in the cabin, and there is room for improvement in passenger safety.

[0006] Therefore, in view of the above-mentioned circumstances, a main object of the present application is to provide an aircraft capable of improving the safety of passengers. [Means for solving the problem]

[0007] As one means for solving the above problems, the present disclosure provides an aircraft equipped with a fuel cell system, the aircraft having a fuselage section including a passenger compartment, the fuel cell system having at least one fuel gas tank, and the lower end of the fuel gas tank being located below the lower end of the fuselage section.

[0008] In the above aircraft, the fuel gas tank may be disposed in a position that does not prevent the generation of lift of the aircraft. The fuel gas tank may be in close contact with the fuselage so as to be thermally conductive. The fuel gas tank may further include a tank valve that controls the opening and closing of the fuel gas tank, a seal member may be provided inside the tank valve, and the aircraft may include a cover that covers the tank valve. Effect of the Invention

[0009] In the aircraft of the present disclosure, the lower end of the fuel gas tank is located lower than the lower end of the fuselage. This allows the fuel gas tank to hit the ground before the fuselage during an emergency landing or crash, and the fuel gas tank absorbs the impact of the collision, mitigating the impact on the passenger cabin in the fuselage. Therefore, the aircraft of the present disclosure can improve the safety of passengers. [Brief description of the drawings]

[0010] [Figure 1] 1 is a simplified schematic diagram of an aircraft 10. (a) is a front view of the aircraft 10, and (b) is a side view of the aircraft 10 focusing on the fuselage 1 and the fuel gas tank 4. [Diagram 2] 1 is a schematic diagram showing the arrangement of the fuel gas tanks 4 when the aircraft 10 is equipped with multiple fuel gas tanks 4. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The aircraft of the present disclosure will be described using an aircraft 10 as one embodiment. A simplified schematic diagram of the aircraft 10 is shown in Fig. 1. (a) is a front view of the aircraft 10, and (b) is a side view of the aircraft 10 focusing on the fuselage 1 and the fuel gas tank 4. In (b), components such as the wing 2 are shown in a see-through manner for the sake of convenience.

[0012] The aircraft 10 is equipped with a fuel cell system and operates using power generated by the fuel cell system. The aircraft 10 is not particularly limited as long as it is an object that can fly in the air. For example, the aircraft 10 includes general aircraft, as well as aircraft such as Cessnas and drones. FIG. 1 shows the aircraft 10 in the form of an aircraft.

[0013] The aircraft 10 includes a fuselage 1 with a passenger cabin and wing sections 2 provided so as to protrude from the sides of the fuselage 1. Here, the "cabin" refers to a room where passengers board and stay, and the passengers include the pilot and the passengers. In other words, the cabin is a concept that includes not only a general passenger cabin but also a cockpit. The wing section 2 is provided with at least one propeller 3 for generating thrust or lift. In FIG. 1, the propellers 3 are arranged vertically at the tip of the wing section 2. Note that the form of the aircraft 10 in FIG. 1 is merely a schematic diagram and is not limited thereto. As long as the aircraft of the present disclosure has at least a fuselage with a passenger cabin, other members are not particularly limited, and the aircraft can be applied to various types of aircraft. For example, a Cessna or a drone can be mentioned.

[0014] The fuel cell system provided in the aircraft 10 is not particularly limited, and a known fuel cell system for aircraft can be adopted. For example, the fuel cell system includes at least a fuel cell, a fuel gas supplying means for supplying a fuel gas (e.g., hydrogen gas) to the fuel cell, and an oxidizing gas supplying means for supplying an oxidizing gas (e.g., air) to the fuel cell. This configuration is similar to that of a general fuel cell system and is known. The fuel cell system also includes at least one fuel gas tank 4. In FIG. 1, two fuel gas tanks 4 are disposed below the fuselage 1. The fuel gas tanks 4 store the fuel gas to be supplied to the fuel cell. As the fuel gas tank 4, a known fuel gas tank provided in an aircraft can be used. For example, a fuel gas tank having a cylindrical plastic liner wrapped with carbon fiber to improve its strength can be used.

[0015] The fuel gas tank 4 is provided at one end with a tank valve 5 that controls the opening and closing of the fuel gas tank 4, and the tank valve 5 is provided with a seal member for preventing fuel gas leakage. The type of seal member is not particularly limited, and a known seal member such as an O-ring can be used. In FIG. 1, the tank valve 5 is arranged facing the front side of the aircraft 10, but this is not limited thereto, and various arrangements of the fuel gas tank 4 can be applied as shown in FIG. 2 described later. However, when a cover 7 described later is provided, it is preferable to arrange the fuel gas tank 4 so that the tank valve faces the front side.

[0016] Here, one feature of the aircraft 10 is that the lower end of the fuel gas tank 4 is located lower than the lower end of the fuselage 1. As a result, in the event of an emergency landing or crash, the fuel gas tank 4 hits the ground before the fuselage 1, and the fuel gas tank 4 absorbs the impact of the impact, mitigating the impact on the passenger compartment provided in the fuselage 1. In addition, when landing on water, the buoyancy of the fuel gas tank 4 can prevent the aircraft 10 from sinking. Furthermore, during normal flight, the weight of the fuel gas tank 4 can position the center of gravity of the aircraft 10 downward, enabling stable flight. Therefore, the aircraft 10 can improve the safety of passengers.

[0017] In order to achieve the above effect, it is sufficient that the lower end of the fuel gas tank 4 is located below the lower end of the fuselage 1, but preferably the lower end of the fuel gas tank 4 is located 200 mm or more, more preferably 400 mm or more below the lower end of the fuselage 1 (see X in FIG. 1(b)). This ensures that the fuel tank comes into contact with the ground, further improving passenger safety. There is no particular upper limit, but taking into consideration the maneuverability of the aircraft 10, the lower end of the fuel gas tank 4 is located 800 mm or less, preferably 600 mm or less, from the lower end of the fuselage 1.

[0018] Furthermore, the fuel gas tank 4 may be disposed in a position that does not interfere with the generation of lift of the aircraft 10. For example, the fuel gas tank 4 may not be disposed below the propeller 3, which is the lift generating source of the aircraft 10. This makes it easier to ensure lift.

[0019] The fuel gas tank 4 may also be located in the center of the front direction of the aircraft 10. This can suppress an increase in the yaw moment of inertia and make it difficult to hinder the turning of the aircraft 10. Here, the center refers to a region in the width direction of the front direction of the aircraft that is within a range of 40 to 60% when the length from one end to the other end is taken as 100%.

[0020] When the aircraft 10 is equipped with multiple fuel gas tanks 4, a preferred arrangement of the fuel gas tanks 4 is shown in Fig. 2. However, the arrangement shown in Fig. 2 is merely an example, and the arrangement of the fuel gas tanks 4 is not limited to this.

[0021] 1(a) shows an embodiment in which the fuel gas tanks 4 are arranged with their orientations staggered. If the orientation of the fuel gas tanks 4 is constant, i.e., if the tank valves 5 of each fuel gas tank 4 are arranged in the same direction, there is a risk that the weight of the tank valves 5 will upset the weight balance of the aircraft 10. Therefore, by arranging the fuel gas tanks 4 with their orientations staggered as in 1(a), it is possible to suppress a decrease in the weight balance of the aircraft 10 due to the weight of the tank valves 5.

[0022] Also, (b) shows an embodiment in which an upper fuel gas tank group is arranged approximately perpendicular to a lower fuel gas tank group in which multiple fuel gas tanks 4 are arranged. This can improve the buoyancy provided by the fuel gas tanks 4.

[0023] Furthermore, (c) and (d) show the fuel gas tanks 4 arranged radially. (c) is a view observed from above, and (d) is a view observed from the side. By arranging the fuel gas tanks 4 radially in this way and positioning one end of each fuel gas tank 4 lower than the other end, it is possible to improve the shock absorbing capacity.

[0024] Returning to Fig. 1, the flying object 10 will be further described. In addition to the safety issues mentioned above, the flying object 10 has the following problems. When the fuel gas tank 4 is filled with fuel gas, the tank temperature rises due to compression of the fuel gas, which reduces the filling efficiency and reduces the amount of fuel gas carried.

[0025] To prevent this, the fuel gas tank 4 may be in close contact with the fuselage 1 in the aircraft 10 so as to be thermally conductive. As a result, even if the temperature of the fuel gas tank 4 rises due to compression of the fuel gas when the fuel gas is being filled, the heat of the fuel gas tank 4 is conducted to the fuselage 1, suppressing the rise in temperature of the fuel gas tank 4 and making it possible to suppress a decrease in the filling efficiency and a decrease in the amount of fuel gas filled.

[0026] Here, "the fuel gas tank 4 is in close contact with the body 1 so as to be capable of thermal conduction" means that the fuel gas tank 4 is in close contact with the body 1 directly or via a thermal conductor 6. Preferably, as shown in FIG. 1, the fuel gas tank 4 is in close contact with the body 1 via a thermal conductor 6. The thermal conductor 6 may be made of a material having a thermal conductivity of 1 to 300 W / m / K. For example, the material may be metal such as iron, copper, or aluminum (thermal conductivity: 10 to 300 W / m / K), or thermally conductive grease (thermal conductivity: 1 to 10 W / m / K). By bringing the fuel gas tank 4 into close contact with the body 1 via the thermal conductor 6, the contact area between the fuel gas tank 4 and the body 1 can be increased, and the thermal conductivity between the fuel gas tank 4 and the body 1 can be improved.

[0027] Furthermore, when the aircraft 10 is continuously operated in a cold environment, there is a problem that the sealing performance of the sealing member provided inside the tank valve 5 is deteriorated. Since the sealing member has a role of preventing leakage of the fuel gas, the deterioration of the sealing performance of the sealing member may cause the fuel gas to leak.

[0028] Therefore, the flying vehicle 10 is provided with a cover 7 that covers the tank valve 5. This prevents the tank valve 5 from being cooled, and prevents deterioration of the sealing performance of the seal member inside the tank valve due to continuous use of the flying vehicle in a cold environment.

[0029] The cover 7 is not particularly limited as long as it is made of a material that is rigid enough not to be deformed by wind pressure when the aircraft 10 is in operation. Examples of the material include aluminum alloy, glass fiber, and carbon fiber. These materials are relatively lightweight and have the advantage of being easy to process and attach.

[0030] As shown in Fig. 1, it is preferable that the cover 7 covers the periphery of the tank valve 5. In other words, it is preferable that the cover 7 covers at least a portion of the tank valve 5 and the fuel gas tank 4 when viewed from the front of the aircraft 10 (or the tank valve 5). It is more preferable that the cover 7 covers the entire surfaces of the tank valve 5 and the fuel gas tank 4 when viewed from the front of the aircraft 10 (or the tank valve 5) (see Fig. 1(a)). This can further suppress cooling of the tank valve 5.

[0031] The flying object of the present disclosure has been described above using one embodiment of the flying object 10. The flying object 10 of the present disclosure can improve the safety of passengers. [Explanation of symbols]

[0032] 1. Body 2 Wings 3 Propeller 4 Fuel Gas Tank 5 Tank Valve 6. Thermal Conductors 7 Cover 10 Flying Objects

Claims

1. An aircraft equipped with a fuel cell system, The aircraft has a fuselage with a passenger cabin; the fuel cell system includes at least one fuel gas tank; a lower end of the fuel gas tank is located below a lower end of the body portion, the fuel gas tank and the body portion are in direct contact with each other over the entire surface of the contact area between the fuel gas tank and the body portion, or are in close contact with each other over the entire surface of the contact area between the fuel gas tank and the body portion with a thermal conductor provided therebetween, the fuel gas tank includes a tank valve for controlling opening and closing of the fuel gas tank; A seal member is provided inside the tank valve, The flying vehicle is provided with a cover that covers the tank valve. Flying vehicle.

2. 2. The flying vehicle according to claim 1, wherein the fuel gas tank is disposed at a position that does not interfere with the generation of lift of the flying vehicle.

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