Fuel supply system and vehicle

Abstract

To provide a fuel tank capable of suitably delivering liquid ammonia from the fuel tank without requiring a fuel pump for delivering the liquid ammonia.SOLUTION: A fuel tank for an internal combustion engine using hydrogen gas or liquid ammonia as fuel, in which the hydrogen gas and the liquid ammonia are stored, includes a first delivery port as a delivery port of the hydrogen gas, and a second delivery port as a delivery port of the liquid ammonia.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed in this specification relates to a fuel tank and a vehicle equipped with the same.

Background Art

[0002] Patent Document 1 discloses an engine that uses liquid ammonia as fuel. In Patent Document 1, liquid ammonia stored in a fuel tank is supplied to a cylinder and burned to generate combustion gas, and the combustion gas is used as power for the engine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a fuel tank used for an engine, generally, a fuel pump for boosting the liquid ammonia stored inside and discharging it to the outside is provided. In this specification, a technology is provided that can preferably discharge liquid ammonia from a fuel tank without requiring a fuel pump for discharging liquid ammonia.

Means for Solving the Problems

[0005] This specification discloses, as a first aspect, a fuel tank for an internal combustion engine that uses hydrogen gas or liquid ammonia as fuel. The hydrogen gas and the liquid ammonia are stored in the fuel tank, and the fuel tank includes a first discharge port that is a discharge port for the hydrogen gas and a second discharge port that is a discharge port for the liquid ammonia.

[0006] In the fuel tank described above, both hydrogen gas and liquid ammonia are stored inside. Since the hydrogen gas in the fuel tank is under high pressure, the pressure of the hydrogen gas acts on the liquid ammonia. Therefore, when liquid ammonia is discharged from the second outlet, the pressure of the hydrogen gas causes the liquid ammonia to be discharged at high pressure from the fuel tank. Thus, this fuel tank can discharge high-pressure liquid ammonia without requiring a fuel pump to pressurize and discharge it. Furthermore, hydrogen gas can be discharged from the first outlet in this fuel tank. Therefore, the hydrogen gas stored in the fuel tank can be used directly as fuel.

[0007] In a second embodiment, the ratio of hydrogen gas to liquid ammonia stored in the fuel tank may be changed according to the ambient temperature, as in the first embodiment. In regions or seasons with low ambient temperatures, the combustion efficiency of liquid ammonia decreases. For this reason, for example, in regions with low ambient temperatures, the combustion efficiency can be improved by increasing the ratio of hydrogen gas stored in the fuel tank and using hydrogen gas as fuel.

[0008] This specification also discloses, in a third aspect, a vehicle comprising an internal combustion engine that uses hydrogen gas or liquid ammonia as fuel, and a fuel tank for storing the hydrogen gas and the liquid ammonia. The fuel tank comprises a first outlet which is the outlet for the hydrogen gas, and a second outlet which is the outlet for the liquid ammonia. The first and second outlets are connected to the internal combustion engine.

[0009] The vehicle described above is equipped with a fuel tank that stores both hydrogen gas and liquid ammonia internally. Because the hydrogen gas in the fuel tank is under high pressure, the liquid ammonia is also affected by the hydrogen gas pressure. Therefore, when liquid ammonia is discharged from the second outlet, the hydrogen gas pressure causes the liquid ammonia to be discharged from the fuel tank at high pressure. Consequently, the vehicle can supply high-pressure liquid ammonia to the internal combustion engine without requiring a fuel pump to pressurize and discharge the liquid ammonia. Furthermore, hydrogen gas can be discharged from the first outlet of this fuel tank. Therefore, the vehicle can also run using the hydrogen gas stored in the fuel tank directly as fuel.

[0010] In a fourth embodiment, in the third embodiment, when the fuel tank is mounted on the vehicle, the first outlet of the fuel tank may be located above the second outlet. Hydrogen gas has a lower specific gravity than liquid ammonia. Therefore, when the fuel tank is mounted on the vehicle, by positioning the first outlet from which hydrogen gas is discharged above the second outlet from which liquid ammonia is discharged, hydrogen gas and liquid ammonia can be stably supplied to the internal combustion engine.

[0011] In a fifth embodiment, the fuel tank may be configured to be detachable from the vehicle in the third or fourth embodiment. In such a configuration, for example, the fuel tank can be removed (i.e., carried separately) and filled with hydrogen gas or liquid ammonia. Furthermore, even if there is no means of refueling, the user can continue to operate the vehicle by replacing the fuel tank with a spare fuel tank, thus improving user convenience. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic diagram showing the configuration of a fuel tank and internal combustion engine according to an embodiment. [Modes for carrying out the invention]

[0013] The fuel tank 2 of this embodiment will now be described with reference to the drawings. The fuel tank 2 is mounted together with the internal combustion engine 3, for example, in a vehicle 10. As shown in Figure 1, hydrogen gas 4 and liquid ammonia 5 are stored inside the fuel tank 2. The fuel tank 2 shown in Figure 1 corresponds to the orientation when it is actually mounted and used in a vehicle 10. That is, the vertical direction of the fuel tank 2 in Figure 1 corresponds to the vertical direction. Hydrogen gas 4 has a lower specific gravity than liquid ammonia 5. Therefore, as shown in Figure 1, liquid ammonia 5 occupies the space below the fuel tank 2, and hydrogen gas 4 occupies the space above the fuel tank 2.

[0014] The fuel tank 2 has a first discharge port 8 and a second discharge port 9. The first discharge port 8 is located on the upper surface 2a of the fuel tank 2. The second discharge port 9 is located on the lower part of the side surface 2b of the fuel tank 2. The space within the fuel tank 2 that is in contact with the first discharge port 8 is filled with hydrogen gas 4, and the space that is in contact with the second discharge port 9 is filled with liquid ammonia 5. In other words, the fuel tank 2 is configured so that hydrogen gas 4 is discharged to the outside from the first discharge port 8 and liquid ammonia 5 is discharged to the outside from the second discharge port 9. The positions of the first discharge port 8 and the second discharge port 9 may be adjusted as appropriate according to the ratio (volume) of hydrogen gas 4 and liquid ammonia 5 stored inside the fuel tank 2.

[0015] Furthermore, the fuel tank 2 is configured to be detachable from the vehicle 10. Therefore, for example, it is possible to fill the inside of the fuel tank 2 with hydrogen gas 4 or liquid ammonia 5 while the fuel tank 2 is removed, or to replace the fuel tank 2 with a spare fuel tank 2.

[0016] The internal combustion engine 3 includes a cylinder 11 having a combustion chamber 11a inside, a hydrogen gas supply device 12 that supplies hydrogen gas 4 into the combustion chamber 11a, an ammonia supply device 13 that supplies liquid ammonia 5 into the combustion chamber 11a, an intake device 14 that supplies air into the combustion chamber 11a, an ignition device 15 that generates a spark in the combustion chamber 11a, and an exhaust device 16 that discharges exhaust gas after combustion from the combustion chamber 11a.

[0017] The cylinder 11 includes a cylindrical cylinder liner 11b, a cylinder head 11c covering the upper opening of the cylinder liner 11b, a piston 11d reciprocating within the cylinder liner 11b, and a crank 11e connected to the piston 11d. The space enclosed by the cylinder liner 11b, the cylinder head 11c, and the piston 11d is the combustion chamber 11a. Therefore, the combustion chamber 11a is compressed to a high-pressure state when the piston 11d moves upward in the figure. Furthermore, by burning hydrogen gas 4 or liquid ammonia 5 in this combustion chamber 11a and causing the piston 11d to reciprocate, a driving force is transmitted that rotates the crank 11e.

[0018] The intake system 14 includes an intake pipe 14a, one end of which is fixed to the cylinder head 11c, and an intake valve 14b provided inside the intake pipe 14a. The intake valve 14b is configured to be opened and closed by a drive mechanism (not shown), and by opening the intake valve 14b, the inside of the intake pipe 14a and the combustion chamber 11a are connected, and air is supplied from the intake pipe 14a into the combustion chamber 11a.

[0019] The exhaust system 16 includes an exhaust pipe 16a, one end of which is fixed to the cylinder head 11c, and an exhaust valve 16b provided inside the exhaust pipe 16a. The exhaust valve 16b is configured to be opened and closed by a drive mechanism (not shown), and when the exhaust valve 16b is opened, the inside of the exhaust valve 16b and the combustion chamber 11a are connected, and the exhaust gas after combustion in the combustion chamber 11a is discharged from the exhaust valve 16b.

[0020] The ignition device 15 consists of, for example, an ignition plug, and is fixed in a state where the tip is disposed in the combustion chamber 11a at substantially the center of the cylinder head 11c. An ignition portion 15a for generating a spark is provided at the tip of the ignition device 15 at the upper central portion in the combustion chamber 11a.

[0021] The hydrogen gas supply device 12 is, for example, an injector and is connected to the first discharge port 8 of the fuel tank 2. The hydrogen gas supply device 12 is fixed in a state where the tip is disposed in the combustion chamber 11a in the cylinder head 11c. An injection portion 12a for injecting hydrogen gas 4 into the combustion chamber 11a is provided at the tip of the hydrogen gas supply device 12. Although the hydrogen gas supply device 12 is fixed to the cylinder head 11c in a state where the injection portion 12a is disposed in the combustion chamber 11a, instead of or in addition to this, it may be fixed to the intake pipe 14a in a state where the injection portion 12a is disposed in the intake pipe 14a.

[0022] The ammonia supply device 13 is, for example, an injector and is connected to the second discharge port 9 of the fuel tank 2. The ammonia supply device 13 is fixed in a state where the tip is disposed in the combustion chamber 11a in the cylinder head 11c. An injection portion 13a for injecting liquid ammonia 5 into the combustion chamber 11a is provided at the tip of the ammonia supply device 13. Although the ammonia supply device 13 is fixed to the cylinder head 11c in a state where the injection portion 13a is disposed in the combustion chamber 11a, instead of or in addition to this, it may be fixed to the intake pipe 14a in a state where the injection portion 13a is disposed in the intake pipe 14a.

[0023] In the internal combustion engine 3 configured as described above, the hydrogen gas 4 injected from the injection portion 12a or the liquid ammonia 5 injected from the injection portion 13a burns together with air in the combustion chamber 11a by the spark generated by the ignition portion 15a, thereby enabling the crank 11e to perform a rotational motion.

[0024] As described above, in the fuel tank 2 of the present embodiment, hydrogen gas 4 and liquid ammonia 5 are both stored inside. Since the hydrogen gas 4 in the fuel tank 2 is at high pressure, the pressure of the hydrogen gas 4 acts on the liquid ammonia 5. Therefore, when discharging the liquid ammonia 5 from the second discharge port 9, the liquid ammonia 5 is discharged from the fuel tank 2 at high pressure due to the pressure of the hydrogen gas 4. Thus, in the fuel tank 2 of the present embodiment, high-pressure liquid ammonia 5 can be discharged without the need for a fuel pump for boosting the pressure of the liquid ammonia 5. Also, in this fuel tank 2, the hydrogen gas 4 can be discharged from the first discharge port 8. Therefore, the hydrogen gas 4 stored in the fuel tank 2 can be directly used as fuel.

[0025] Also, in the present embodiment, in the state where the fuel tank 2 is mounted on the vehicle 10, the first discharge port 8, which is the discharge port of the hydrogen gas 4, is provided on the upper surface 2a of the fuel tank 2, and the second discharge port 9, which is the discharge port of the liquid ammonia 5, is provided on the side surface 2b of the fuel tank 2. The specific gravity of the hydrogen gas 4 is smaller than that of the liquid ammonia 5. Therefore, in the state where the fuel tank 2 is mounted on the vehicle 10, by positioning the first discharge port 8 from which the hydrogen gas 4 is discharged above the second discharge port 9 from which the liquid ammonia 5 is discharged, the hydrogen gas 4 and the liquid ammonia 5 can be stably supplied to the internal combustion engine 3.

[0026] Also, in the present embodiment, the fuel tank 2 is configured to be detachable from the vehicle 10. Therefore, when the fuel (hydrogen gas 4 or liquid ammonia 5) in the fuel tank 2 runs out, the vehicle 10 can continue to run by carrying only the fuel tank 2 to fill the fuel or by replacing the fuel tank 2 with a spare (i.e., a fuel tank in which fuel is stored) fuel tank 2, which is highly convenient for the user.

[0027] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above. Below, we list some variations of the embodiments described above.

[0028] In the above-described embodiment, a reformer for vaporizing and reforming liquid ammonia 5 may be further provided. By reforming liquid ammonia 5, a combustion gas containing hydrogen can be produced. Therefore, the combustion gas produced by such a reformer may be used as fuel.

[0029] Alternatively, for example, hydrogen may be extracted from the combustion gas produced by the reformer and supplied to the fuel tank 2. This configuration allows for changes in the ratio of hydrogen gas 4 to liquid ammonia 5 stored in the fuel tank 2. This makes it possible to adjust the pressure of the hydrogen gas 4 in the fuel tank 2.

[0030] Furthermore, the ratio of hydrogen gas 4 to liquid ammonia 5 stored in the fuel tank 2 may be adjusted depending on the outside temperature and season of the sales area of ​​the fuel tank 2. For example, in areas or seasons with low outside temperatures, the combustion efficiency of liquid ammonia 5 decreases. Therefore, for example, in areas with low outside temperatures, increasing the proportion of hydrogen gas 4 stored in the fuel tank 2 allows the easily combustible hydrogen gas 4 to be used primarily as fuel, thereby improving combustion efficiency.

[0031] The technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of symbols]

[0032] 2: Fuel tank, 2a: Top view, 2b: Side view, 3: Internal combustion engine, 4: Hydrogen gas, 5: Liquid ammonia, 8: First discharge port, 9: Second discharge port, 10: Vehicle, 11: Cylinder, 12: Hydrogen gas supply device, 13: Ammonia supply device, 14: Intake device, 15: Ignition device, 16: Exhaust device

Claims

1. A fuel supply device that supplies fuel to an internal combustion engine that uses hydrogen gas or liquid ammonia as fuel, The vehicle is equipped with a fuel tank for storing the hydrogen gas and the liquid ammonia, The fuel tank comprises a first discharge port which is the discharge port for hydrogen gas and a second discharge port which is the discharge port for liquid ammonia. The first discharge port and the second discharge port are connected to the internal combustion engine. A fuel supply system in which a fuel pump is not provided in the flow path of the liquid ammonia that flows from the second discharge port to the internal combustion engine.

2. A fuel supply device according to claim 1, A fuel supply device in which the ratio of hydrogen gas and liquid ammonia stored in the fuel tank can be changed according to the ambient temperature.

3. A vehicle comprising an internal combustion engine that uses hydrogen gas or liquid ammonia as fuel, and a fuel tank for storing the hydrogen gas and the liquid ammonia, The fuel tank comprises a first discharge port which is the discharge port for hydrogen gas and a second discharge port which is the discharge port for liquid ammonia. The first discharge port and the second discharge port are connected to the internal combustion engine. A vehicle in which a fuel pump is not provided in the flow path of the liquid ammonia that flows from the second discharge port to the internal combustion engine.

4. The vehicle according to claim 3, A vehicle in which, when the fuel tank is mounted on the vehicle, the first outlet of the fuel tank is located above the second outlet.

5. A vehicle according to claim 3 or 4, The fuel tank is configured to be detachable from the vehicle.

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