High pressure gas storage device

Abstract

To consume high pressure gas leaked from an inside of a tank as a reducing agent of NOx.SOLUTION: A high pressure gas storage device 10 includes a tank 20 for storing high pressure gas containing vaporized gas having a function of reducing NOx and a function as fuel of an internal combustion engine 110, an outer shell body 30 disposed to form a reserving space S between an outer surface of the tank 20 and the outer shell body 30 so as to surround the tank 20, and a supply unit 80 for supplying the vaporized gas leaked from the tank 20 into the reserving space S into an exhaust unit 130 for discharging exhaust gas from the internal combustion engine 110.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a high-pressure gas storage device. [Background technology]

[0002] Patent Document 1 discloses a combustion device that burns fuel ammonia in a combustor using combustion air. The combustion device includes a catalytic reduction section that reduces nitrogen oxides in the combustion exhaust gas supplied from the combustor. The combustion device supplies at least a portion of the fuel ammonia to the catalytic reduction section as a reducing agent for the nitrogen oxides in the combustion exhaust gas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-162939 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 does not disclose the configuration of a tank for storing fuel ammonia, etc. For example, if the tank for storing fuel ammonia is a conventional tank, there is a risk that the ammonia may be released into the atmosphere if it leaks from the tank. Therefore, measures against gas leaking from the tank are required.

[0005] The present invention was developed in view of the above circumstances, and has an object to make it possible to consume high-pressure gas leaking from inside a tank as a reducing agent for NOx. [Means for solving the problem]

[0006] The high pressure gas storage device of the present invention comprises: A tank for storing high-pressure gas including a vaporized gas having a function of reducing NOx and a function as a fuel for an internal combustion engine; An outer shell surrounding the tank, the outer shell being disposed to leave a storage space between the outer shell and the outer surface of the tank; a supply section that supplies the vaporized gas leaked from the tank to the storage space to an exhaust section that exhausts exhaust gas from the internal combustion engine; Equipped with. Effect of the Invention

[0007] According to this configuration, the high-pressure gas leaking from inside the tank can be consumed as a reducing agent for NOx. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram illustrating a vehicle-mounted system including a high-pressure gas storage device according to a first embodiment. [Diagram 2] Partial cross-sectional side view of a high-pressure gas storage device [Diagram 3] A block diagram illustrating a schematic electrical configuration of an in-vehicle system including a high-pressure gas storage device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] It is preferable to include a concentration sensor that detects the concentration of the vaporized gas in the holding space, an on-off valve that switches between an open state that allows the vaporized gas to pass from the holding space to the exhaust section and a closed state that blocks the vaporized gas from passing from the holding space to the exhaust section, and a control unit that controls the on-off valve to switch from the closed state to the open state when the concentration detected by the concentration sensor reaches a predetermined high level. With this configuration, when the concentration of the vaporized gas in the holding space reaches a predetermined high level, the on-off valve is opened to supply the vaporized gas from the holding space to the exhaust section. This improves the catalytic action of the vaporized gas.

[0010] It is preferable that the supply unit further includes a pump for feeding the vaporized gas from the holding space to the exhaust unit. With this configuration, the vaporized gas in the holding space can be effectively fed to the exhaust unit.

[0011] It is preferable to provide a control valve for sending the vaporized gas from the tank to the holding space. With this configuration, the vaporized gas in the tank can be actively caused to flow into the holding space, thereby increasing the concentration of the vaporized gas supplied to the exhaust section.

[0012] It is preferable that the high pressure gas is ammonia, and the outlet of the vaporized gas to the supply part in the holding space is disposed at the upper end of the outer shell. With this configuration, the vaporized gas remains in a high region in the holding space, and can be reliably sent to the exhaust part.

[0013] <Example 1> A first embodiment of the present invention will be described below with reference to Figs. 1 to 3. In the following description, the F direction in Fig. 2 is defined as the front with respect to the front-rear direction, and the H direction in Fig. 2 is defined as the top with respect to the up-down direction.

[0014] (In-vehicle system configuration) The high-pressure gas storage device 10 of the first embodiment is used in an in-vehicle system 100, as shown in Fig. 1. The in-vehicle system 100 is mounted on a vehicle. The in-vehicle system 100 is a system that supplies high-pressure gas and combustion air to an internal combustion engine 110 by the high-pressure gas storage device 10.

[0015] The in-vehicle system 100 includes a high-pressure gas storage device 10, an internal combustion engine 110, an intake section 120, and an exhaust section 130. The internal combustion engine 110 is, for example, an engine that generates driving force using high-pressure gas. The intake section 120 is, for example, a natural intake port provided in a vehicle, and introduces combustion air.

[0016] The exhaust section 130 has an exhaust path 131 and an exhaust gas treatment unit 132. The exhaust path 131 exhausts exhaust gas from the internal combustion engine 110. The exhaust path 131 is a passage that guides the exhaust gas discharged from the internal combustion engine 110 to the outside of the vehicle. An exhaust gas treatment unit 132 is provided in the middle of the exhaust path 131. The exhaust gas treatment unit 132 converts harmful substances in the exhaust gas, such as nitrogen oxides (NOx), into harmless components using a catalyst or the like. The exhaust path 131 releases the exhaust gas treated by the exhaust gas treatment unit 132 to the outside of the vehicle.

[0017] (Configuration of high pressure gas storage device) The high-pressure gas storage device 10 is mounted on, for example, a vehicle (not shown) for use. The high-pressure gas storage device 10 is configured to include a tank 20 and an outer shell 30 that surrounds the tank 20. The tank 20 and the outer shell 30 are disposed inside the vehicle (for example, in the luggage compartment) or outside the vehicle (under the floor of the body). The tank 20 is an airtight storage tank for storing high-pressure gas (high-pressure liquefied gas and vaporized gas). Liquefied gas is a gas that is in the vapor phase at room temperature and atmospheric pressure and is phase-transitioned to the liquid phase by pressurization and cooling. High-pressure vaporized gas is a gas generated by evaporation of the liquefied gas.

[0018] The high-pressure gas (liquefied gas and vaporized gas) stored in the high-pressure gas storage device 10 has a function as fuel for the internal combustion engine 110 (gas fuel for a vehicle engine) and a function of reducing NOx. Specifically, the high-pressure gas is ammonia. Since ammonia is a harmful substance, an outer shell body 30 is provided as a measure in the unlikely event that the high-pressure gas (ammonia gas) in the tank 20 leaks out of the tank 20. The outer shell body 30 surrounds the tank 20, leaving a storage space S open for temporarily storing the high-pressure gas.

[0019] 2, the tank 20 has, for example, one tube portion 21 and a pair of dome portions 22, and is capsule-shaped as a whole. The tube portion 21 is a cylindrical portion with its axis oriented horizontally (front-rear direction). The pair of dome portions 22 are approximately hemispherical portions and are arranged so as to close the openings at both ends of the tube portion 21. For example, the tube portion 21 and the pair of dome portions 22 are made of metal members manufactured as separate parts, and are hermetically joined together by welding to be integrated.

[0020] For example, the tank 20 is supported by the outer shell 30 via a plurality of legs (not shown). The plurality of legs (not shown) extend downward from the cylindrical portion 21, for example.

[0021] The outer shell 30 is a capsule-shaped member that airtightly surrounds the entire tank 20 with a gap therebetween. The space between the outer surface of the tank 20 and the inner surface of the outer shell 30 functions as a retention space S for temporarily storing high-pressure gas (vaporized gas) that leaks from the tank 20. The entire outer surface area of ​​the tank 20 and the entire inner surface area of ​​the outer shell 30 face the retention space S.

[0022] The outer shell 30 has, for example, one tubular member 31 and a pair of dome-shaped members 32, and is capsule-shaped as a whole. The tubular member 31 is a cylindrical member with its axis oriented horizontally (front-rear direction), and is disposed coaxially with the tubular portion 21 of the tank 20. The pair of dome-shaped members 32 are portions each having a substantially hemispherical shape, and are disposed so as to close the openings at both ends of the tubular member 31.

[0023] The outer shell 30 (the cylindrical member 31 and the dome-shaped member 32) is configured to include, for example, a metal base member (not shown) and a reinforcing layer attached to the outer surface of the base member. The reinforcing layer is configured by attaching a plurality of elongated reinforcing sheets made of, for example, carbon fiber reinforced plastic (CFRP) in layers to the outer surface of the base member.

[0024] For example, a tube side flange (not shown) provided on the opening edge of the tubular member 31 and a dome side flange (not shown) provided on the opening edge of the dome-shaped member 32 are fastened to each other, thereby integrating the tubular member 31 and the dome-shaped member 32.

[0025] 1, the high-pressure gas storage device 10 further includes a fuel pump 23 and a fuel path 50. The fuel pump 23 is attached to the tank 20. The fuel pump 23 pressure-feeds (supplies) high-pressure gas (e.g., liquefied gas) in the tank 20 to the internal combustion engine 110 via the fuel path 50. The fuel pump 23 is provided, for example, at the bottom of the cylindrical portion 21 of the tank 20. The fuel pump 23 may also be provided at the ceiling portion (upper end portion) of the cylindrical portion 21 of the tank 20. The fuel path 50 is a supply path for high-pressure gas, and is provided between the tank 20 and the internal combustion engine 110.

[0026] 1, the high-pressure gas storage device 10 further includes an air intake passage 60. The air intake passage 60 is a path that supplies combustion air (outside air) introduced from the intake section 120 to the internal combustion engine 110. The air intake passage 60 is provided between the intake section 120 and the internal combustion engine 110. The air intake passage 60 passes through the retention space S. That is, the air intake passage 60 is connected to the retention space S and the internal combustion engine 110.

[0027] The air supply passage 60 has a first path 61 and a second path 62. The first path 61 is provided between the intake section 120 and the retention space S. The first path 61 is a passage that sends the combustion air (outside air) introduced by the intake section 120 to the retention space S. As a result, air is stored in the retention space S. The second path 62 is provided between the retention space S and the internal combustion engine 110. The second path 62 is a passage that sends gas (combustion air and vaporized gas) in the retention space S to the internal combustion engine 110.

[0028] A check valve 63 is provided in the first path 61. The check valve 63 is provided in the first path 61 between the intake section 120 and the retention space S. The check valve 63 regulates the flow of combustion air from the retention space S to the intake section 120.

[0029] A control valve 64 is provided in the second path 62. The control valve 64 is provided in the second path 62 between the retaining space S and the internal combustion engine 110. The control valve 64 is configured as, for example, a solenoid valve. The control valve 64 is switched between a closed state and an open state under the control of a control unit 71, which will be described later. When in the open state, the control valve 64 sends out vaporized gas from the retaining space S to the internal combustion engine 110.

[0030] As shown in Fig. 1, the high-pressure gas storage device 10 further includes a bypass 65. The bypass 65 connects the first path 61 and the second path 62. That is, the bypass 65 sends the combustion air (outside air) introduced from the intake unit 120 from the first path 61 to the second path 62. The bypass 65 is provided with a control valve 66. The control valve 66 is configured as, for example, a solenoid valve. The control valve 66 is switched between a closed state and an open state under the control of a control unit 71 described later.

[0031] 1, the high-pressure gas storage device 10 further includes a control valve 24 and a safety valve 25. The control valve 24 and the safety valve 25 are provided in the tank 20.

[0032] The control valve 24 is configured as, for example, a solenoid valve. The control valve 24 is switched between a closed state and an open state under the control of the control unit 71, which will be described later. The control valve 24 is disposed so as to face the inside of the tank 20 and the inside of the retention space S. An opening on the primary side of the control valve 24 faces the inside of the tank 20. An opening on the secondary side of the control valve 24 faces the inside of the retention space S. The control valve 24 sends out vaporized gas from the tank 20 to the retention space S under the control of the control unit 71.

[0033] The safety valve 25 is disposed so as to face the inside of the tank 20 and the inside of the retention space S. An opening on the primary side of the safety valve 25 faces the inside of the tank 20. An opening on the secondary side of the safety valve 25 faces the inside of the retention space S. The safety valve 25 automatically opens when the pressure in the tank 20 excessively increases, and automatically closes as the pressure in the tank 20 drops.

[0034] 1, the high-pressure gas storage device 10 further includes a concentration sensor 33 and a safety valve 34. The concentration sensor 33 and the safety valve 34 are provided in the outer shell 30.

[0035] The concentration sensor 33 detects the concentration of the vaporized gas in the holding space S. The detection result of the concentration sensor 33 (concentration value of the vaporized gas in the holding space S) is input to the control unit 71 and the external control unit 141 described later. The concentration sensor 33 is provided, for example, on the ceiling part (upper end part) of the holding space S (the cylindrical member 31 of the outer shell body 30). For example, air, which is a gas with a higher specific gravity than the vaporized gas (ammonia gas, etc.), may be stored. In this case, the leaked vaporized gas rises in the holding space S, so that the leakage of the vaporized gas can be detected by the concentration sensor 33 at an early stage.

[0036] The safety valve 34 is disposed so as to face the inside of the retention space S and the outside of the shell body 30. The primary side opening of the safety valve 34 faces the inside of the retention space S. The secondary side opening of the safety valve 34 faces the outside of the shell body 30. The safety valve 34 automatically opens when the pressure in the retention space S increases excessively, and automatically closes as the pressure in the retention space S drops.

[0037] 1, the high-pressure gas storage device 10 further includes a supply unit 80. The supply unit 80 supplies the vaporized gas leaked from the tank 20 into the retention space S to the exhaust unit 130. The supply unit 80 includes a supply path 81, an on-off valve 82, and a pump 83.

[0038] The supply path 81 is a passage that sends the vaporized gas in the retention space S to the exhaust path 131. The supply path 81 is provided between the retention space S and the exhaust section 130. More specifically, one end of the supply path 81 is connected to the cylindrical member 31 of the outer shell body 30. The other end of the supply path 81 is connected to the exhaust gas treatment section 132.

[0039] The cylindrical member 31 of the outer shell body 30 is provided with an outlet 35 for the vaporized gas to the supply unit 80. The outlet 35 is disposed at the upper end (ceiling portion) of the cylindrical member 31 of the outer shell body 30. The outlet 35 is connected to one end of a supply path 81.

[0040] The on-off valve 82 is provided in the supply path 81. The on-off valve 82 is configured as, for example, a solenoid valve. The on-off valve 82 is switched between a closed state and an open state under the control of the control unit 71, which will be described later. When in the open state, the on-off valve 82 allows the passage of the vaporized gas from the retention space S to the exhaust section 130. When in the closed state, the on-off valve 82 blocks the passage of the vaporized gas from the retention space S to the exhaust section 130.

[0041] The pump 83 is provided in the supply path 81. The pump 83 sends the vaporized gas from the retention space S to the exhaust section 130. The pump 83 adjusts the amount of the vaporized gas supplied from the retention space S to the exhaust section 130 (more specifically, the exhaust gas treatment section 132) under the control of the control section 71, which will be described later.

[0042] (Electrical configuration of in-vehicle system) 3 is a block diagram illustrating a schematic electrical configuration of the in-vehicle system 100. As shown in FIG. 3, the in-vehicle system 100 includes an external control unit 141 and a high-pressure gas storage device 10.

[0043] The external control unit 141 is configured as, for example, an in-vehicle ECU (electronic control unit). The external control unit 141 is an information processing device having an information processing function and the like. The external control unit 141 is configured mainly with, for example, a microcomputer, and has an arithmetic device such as a CPU (Central Processing Unit), and a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and the like. The external control unit 141 controls the amount of high-pressure gas supplied from the tank 20 to the internal combustion engine 110. For example, the external control unit 141 controls the fuel pump 23 based on a signal related to the operation amount of the accelerator pedal of the vehicle, and controls the amount of fuel (high-pressure gas) supplied. More specifically, the external control unit 141 controls the fuel pump 23 based on the detection result of the concentration sensor 33, and adjusts the amount of high-pressure gas supplied from the tank 20 to the internal combustion engine 110.

[0044] The high-pressure gas storage device 10 includes a control unit 71, a fuel pump 23, a control valve 24, a concentration sensor 33, and an alarm unit 72. The control unit 71 is an information processing device having an information processing function, etc. The control unit 71 is mainly composed of, for example, a microcomputer, and has an arithmetic unit such as a CPU (Central Processing Unit), and a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory). The control unit 71 controls the entire high-pressure gas storage device 10. The control unit 71 controls the fuel pump 23, the control valve 24, the concentration sensor 33, the control valve 64, the control valve 66, and the alarm unit 72.

[0045] The control unit 71 controls the on-off valve 82 of the supply unit 80 to switch from a closed state to an open state when the concentration (detected concentration) detected by the concentration sensor 33 reaches a predetermined high level. The high level of the detected concentration is, for example, a state in which the detected concentration exceeds a predetermined threshold value, a state in which the rate of increase of the detected concentration exceeds a predetermined threshold value, etc. This makes it possible to increase the concentration of the vaporized gas supplied from the reserve space S to the exhaust unit 130 when the on-off valve 82 is in the open state.

[0046] The notification unit 72 is a warning lamp displayed on the instrument panel of the vehicle, a speaker that emits an alarm sound inside the cabin of the vehicle, etc. The notification unit 72 operates based on a control signal (anomaly detection signal) from the control unit 71. The notification unit 72 performs a notification operation, for example, when the concentration of vaporized gas in the retention space S detected by the concentration sensor 33 exceeds a preset threshold value.

[0047] (Function of high pressure gas storage device) Next, the operation of the high-pressure gas storage device 10 of the present embodiment 1 will be described. The tank 20 that stores high-pressure gas is entirely surrounded by an airtight shell body 30. A retention space S is provided between the tank 20 and the shell body 30 to temporarily store vaporized gas that leaks from the tank 20. As a result, even if the high-pressure gas in the tank 20 leaks outside the tank 20, the leaked vaporized gas remains in the retention space S.

[0048] The high-pressure gas storage device 10 includes a supply unit 80 that supplies the vaporized gas leaked from the tank 20 into the retention space S to the exhaust unit 130. With this configuration, the vaporized gas leaked from the tank 20 into the retention space S is sent to the exhaust unit 130 via the supply unit 80 and consumed as a reducing agent for NOx in the exhaust gas exhausted from the internal combustion engine 110. This prevents the NOx in the exhaust gas from being released into the atmosphere. In addition, since the internal pressure of the retention space S does not increase due to the vaporized gas leaking from the tank 20, the outer shell 30 does not need to have excessive strength, making it possible to reduce the weight and size.

[0049] For example, when the vaporized gas in the retaining space S is to be supplied to the internal combustion engine 110 and the exhaust gas treatment unit 132, the control unit 71 opens the control valve 64 and the on-off valve 82 and operates the pump 83. At this time, for example, the control unit 71 closes the control valve 66 of the bypass 65. Also, when the vaporized gas in the retaining space S is to be supplied only to the exhaust gas treatment unit 132, the control unit 71 opens the on-off valve 82, operates the pump 83, and closes the control valve 64. At this time, the control unit 71 opens the control valve 66 in order to supply combustion gas (outside air) to the internal combustion engine 110.

[0050] In the high-pressure gas storage device 10, the control unit 71 controls the on-off valve 82 to switch from a closed state to an open state when the concentration detected by the concentration sensor 33 reaches a predetermined high level. According to this configuration, when the concentration of the vaporized gas in the retention space S reaches a predetermined high level, the on-off valve 82 is opened to supply the vaporized gas from the retention space S to the exhaust unit 130. This can improve the catalytic action of the vaporized gas.

[0051] The high-pressure gas storage device 10 is provided with a pump 83 that is provided in the supply section 80 and sends the vaporized gas from the retention space S to the exhaust section 130. With this configuration, the vaporized gas in the retention space S can be effectively sent to the exhaust section 130.

[0052] The high-pressure gas storage device 10 includes a control valve 24 that sends out vaporized gas from the tank 20 to the retention space S. With this configuration, the vaporized gas in the tank 20 can be actively caused to flow into the retention space S, thereby increasing the concentration of the gas supplied to the exhaust section 130. In addition, the control valve 24 can be opened when NOx reduction is required.

[0053] In the high-pressure gas storage device 10, the high-pressure gas stored in the tank 20 is, for example, ammonia. Outside air can be introduced into the retention space S via the first path 61 of the air supply passage 60. This allows air to be stored in the retention space S. The outlet 35 for the vaporized gas to the supply section 80 in the retention space S is disposed at the upper end (ceiling section) of the cylindrical member 31 of the outer shell body 30. With this configuration, the vaporized gas remains in a high region within the retention space S, and can be reliably sent to the exhaust section 130.

[0054] <Other Examples> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the present invention. In the first embodiment, the liquefied gas and the vaporized gas are stored in the tank 20, but only the high-pressure vaporized gas may be stored in the tank 20. This high-pressure vaporized gas is not a gas generated by evaporation of the liquefied gas, but a gas that maintains a gas phase similar to that under atmospheric pressure during the pressurization process. In the first embodiment, the gas stored in the holding space S may have a lower specific gravity than the vaporized gas. In this case, the outlet 35 connected to the supply unit 80 and the concentration sensor 33 are preferably disposed at the lower end of the holding space S. In the first embodiment, the intake section 120 is a natural intake port. However, in the case where the internal combustion engine is a supercharged internal combustion engine, the intake section 120 may be a device that compresses and sends out the intake air. In the first embodiment, the check valve 63 may be a control valve that is controlled to open and close by the control unit 71. This control valve is closed, for example, when the concentration of the vaporized gas flowing out from the tank 20 into the holding space S is to be increased. In the first embodiment, the air supply passage 60 may not pass through the retaining space S. That is, the vaporized gas in the retaining space S may be supplied only to the exhaust gas treatment unit 132. In the first embodiment, the fuel pump 23 is given as an example of the adjusting unit. However, a control valve provided in the fuel passage 50 may also be used. In the first embodiment, the control unit 71 and the external control unit 141 may be configured as one and the same control unit. [Explanation of symbols]

[0055] 10: High pressure gas storage device 20: Tank 21: Cylinder part 22: Dome section 23: Fuel pump 24: Control valve 25: Safety valve 30: Exoskeleton 31: Cylindrical member 32: Dome-shaped member 33: Concentration sensor 34: Safety valve 35: Outlet 50: Fuel path 60: Air supply path 61: First Route 62: Second Route 63: Check valve 64: Control valve 65: Bypass 66: Control valve 71: Control section 72: Information Department 80: Supply section 80: Exhaust section 81: Supply route 82: On-off valve 83: Pump 100: In-vehicle systems 110: Internal combustion engine 120: Intake section 130: Exhaust section 131: External control unit 131: Exhaust duct 132: Exhaust gas treatment unit 141: External control unit S: Holding space

Claims

1. A tank for storing high-pressure gas including a vaporized gas having a function of reducing NOx and a function as a fuel for an internal combustion engine; An outer shell surrounding the tank, the outer shell being disposed to leave a storage space between the outer shell and the outer surface of the tank; a supply section that supplies the vaporized gas leaked from the tank to the storage space to an exhaust section that exhausts exhaust gas from the internal combustion engine; A high-pressure gas storage device comprising:

2. a concentration sensor for detecting a concentration of the vaporized gas in the holding space; an on-off valve that switches between an open state that allows the vaporized gas to pass from the holding space to the exhaust unit and a closed state that blocks the vaporized gas from passing from the holding space to the exhaust unit; a control unit that controls the on-off valve to switch from the closed state to the open state when the concentration detected by the concentration sensor reaches a predetermined high level; The high pressure gas storage device according to claim 1 .

3. 3. The high-pressure gas storage device according to claim 1, further comprising a pump provided in the supply section for feeding the vaporized gas from the reserve space to the exhaust section.

4. 3. The high-pressure gas storage device according to claim 1, further comprising a control valve for sending the vaporized gas from the tank to the storage space.

5. the propellant is ammonia, 3. The high-pressure gas storage device according to claim 1, wherein an outlet port for the vaporized gas to the supply portion in the storage space is disposed at an upper end of the outer shell.

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