Engine system

Abstract

To provide an engine system that detects abnormalities in response to an increase in the supply of ammonia to a hydrogen production device. [Solution] The engine system comprises a hydrogen production device, a co-firing engine, a hydrogen supply path, a first oxygen supply path, a first ammonia supply path, an oxygen sensor, and a control means. The hydrogen production apparatus comprises a catalyst unit equipped with a combustion catalyst and an ammonia decomposition catalyst, a second ammonia supply path, and a second oxygen supply path. The catalyst unit is connected to the hydrogen supply path upstream of the oxygen sensor. The control means increases the amount of ammonia supplied from the second ammonia supply path to the catalyst unit in accordance with the increase in oxygen detected by the oxygen sensor, and detects an abnormality when the amount of ammonia supplied exceeds a threshold.

Description

Technical Field

[0001] The present invention relates to an engine system.

Background Art

[0002] In recent years, from the viewpoint of environmental protection, engine systems using hydrogen fuel have attracted attention. Such hydrogen fuel is produced, for example, by using an ammonia decomposition catalyst that decomposes ammonia into hydrogen.

[0003] The engine system described in Patent Document 1 below includes an engine, a first flow rate control valve that controls the flow rate of air supplied to the engine, a first fuel supply valve that supplies fuel to the engine, a reformer that reforms ammonia gas to generate reformed gas containing hydrogen, a second fuel supply valve that supplies fuel to the reformer, and an oxygen detection unit. In Patent Document 1 below, based on the oxygen detection result of the oxygen detection unit, when the concentration of oxygen contained in the exhaust gas of the engine is higher than a target value, control is performed to increase the flow rate of ammonia gas supplied to the reformer, thereby maintaining the required air-fuel ratio.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] However, in the engine system of Patent Document 1 mentioned above, the supply amount of ammonia is simply increased according to the increase amount of oxygen, and an abnormality in the reformer cannot be determined. Therefore, a user cannot know that the reformer has failed.

[0006] The present invention provides an engine system that detects an abnormality in response to an increase in the supply amount of ammonia supplied to a hydrogen production apparatus. [Means for solving the problem]

[0007] The present invention [1] includes a hydrogen production apparatus for producing hydrogen, a co-firing engine for co-firing hydrogen, oxygen and ammonia, a hydrogen supply path for supplying hydrogen from the hydrogen production apparatus to the co-firing engine, a first oxygen supply path for supplying oxygen to the co-firing engine, a first ammonia supply path for supplying ammonia to the co-firing engine, an oxygen sensor interposed in the hydrogen supply path, and control means for controlling these, wherein the hydrogen production apparatus includes a catalyst unit comprising a combustion catalyst for burning ammonia and an ammonia decomposition catalyst for decomposing ammonia and producing hydrogen, a second ammonia supply path for supplying ammonia to the catalyst unit, and a second oxygen supply path for supplying oxygen to the catalyst unit, the catalyst unit being connected to the hydrogen supply path upstream of the oxygen sensor, and the control means increasing the amount of ammonia supplied from the second ammonia supply path to the catalyst unit in accordance with the increase in oxygen detected by the oxygen sensor, and detecting an abnormality when the amount of ammonia supplied exceeds a threshold.

[0008] In the engine system described above, ammonia supplied from the second ammonia supply path is burned in the combustion catalyst by oxygen supplied from the second oxygen supply path. Subsequently, the ammonia is decomposed into hydrogen and nitrogen by the ammonia decomposition catalyst, which has reached a temperature at which combustion is optimal, and supplied to the co-firing engine. In the engine system described above, the control means increases the amount of ammonia supplied from the second ammonia supply path to the catalyst unit in accordance with the increase in oxygen detected by the oxygen sensor, and detects an abnormality when the amount of ammonia supplied exceeds a threshold. Therefore, when the amount of oxygen in the hydrogen production device increases to a predetermined amount, a predetermined amount of ammonia is supplied, and an appropriate oxygen concentration can be maintained by using oxygen for the combustion of ammonia. On the other hand, if there is a malfunction in the combustion catalyst or other equipment during the supply of ammonia, and the combustion reaction between ammonia and oxygen does not proceed normally, and the amount (concentration) of ammonia supplied becomes excessive, it will exceed the threshold, and a malfunction in the hydrogen production device can be detected.

[0009] The present invention [2] further includes the engine system described in [1] above, wherein the control means, when it detects an abnormality, suppresses the amount of oxygen supplied from the first oxygen supply path and suppresses the amount of ammonia supplied from the first and / or second ammonia supply path.

[0010] In the engine system described above, when an abnormality is detected, the control means suppresses the amount of oxygen supplied from the first oxygen supply path and the amount of ammonia supplied from the first and / or second ammonia supply path. Therefore, even if the hydrogen production device fails, the engine speed can be reduced and the vehicle can be safely stopped. [Effects of the Invention]

[0011] According to the engine system of the present invention, it is possible to detect malfunctions in the hydrogen production equipment. [Brief explanation of the drawing]

[0012] [Figure 1]Figure 1 is a schematic diagram showing one embodiment of the engine system of the present invention. [Figure 2] Figure 2 is a flowchart illustrating the control of the engine system shown in Figure 1. [Modes for carrying out the invention]

[0013] Referring to Figure 1, one embodiment of the engine system of the present invention will be described in detail. The engine system 1 comprises a hydrogen production device 2, a co-firing engine 3, a hydrogen supply path 10, a first oxygen supply path 11, an ammonia tank 4, a vaporizer 5, a first ammonia supply path 12, an oxygen sensor 6, a check valve 20, a cooler 21, a first oxygen flow rate control valve 22, a first injector 23, a mixture flow rate control valve 24, and a control unit 7.

[0014] <Hydrogen production equipment> The hydrogen production device 2 produces hydrogen. The hydrogen production device 2 is a fuel supply device connected to a co-firing engine 3 that co-fires hydrogen, oxygen, and ammonia. The hydrogen production device 2 comprises a plasma reactor 8, a second ammonia supply path 13, a mixture supply path 14, a second injector 25, a flow path switching valve 26, a second oxygen supply path 15, a second oxygen flow rate control valve 27, and a catalyst unit 9. The hydrogen production device 2 is also equipped with a pump (not shown) at an appropriate location. By driving the pump, ammonia, the mixture (described later), and oxygen can be supplied.

[0015] <Plasma Reactor> The plasma reactor 8 decomposes the ammonia supplied from the ammonia tank 4 (specifically, the third ammonia supply path 13a in the second ammonia supply path 13) into hydrogen and nitrogen.

[0016] The plasma reactor 8 comprises a casing 80 and a plurality of electrodes 81.

[0017] The casing 80 has a hollow cylindrical shape, and is arranged such that its longitudinal direction is along the flow direction of ammonia. The plurality of electrodes 81 are arranged inside the casing 80 along the longitudinal direction of the casing 80. Furthermore, the plurality of electrodes 81 are spaced apart from each other along a direction orthogonal to the longitudinal direction of the casing 80.

[0018] The electrode 81 comprises a conductor (not shown), a dielectric coating the conductor, and an ammonia adsorbing member coating the dielectric.

[0019] Examples of the material for the conductor include tungsten. Examples of the material for the dielectric include alumina.

[0020] The ammonia adsorbing member is a layer formed by coating an ammonia adsorbent on the surface of the dielectric. An example of the ammonia adsorbent is zeolite.

[0021] <second ammonia supply path> The second ammonia supply path 13 comprises a third ammonia supply path 13a and a fourth ammonia supply path 13b.

[0022] The third ammonia supply path 13a supplies ammonia to the plasma reactor 8.

[0023] The upstream end of the third ammonia supply path 13a in the ammonia supply direction is connected to the ammonia tank 4. The downstream end of the third ammonia supply path 13a in the ammonia supply direction is connected to the plasma reactor 8.

[0024] The third ammonia supply path 13a comprises a first pipe 40, a second pipe 41, a third pipe 42, and a fourth pipe 43. In other words, the third ammonia supply path 13a is a path for supplying ammonia from the ammonia tank 4 to the plasma reactor 8 through the first pipe 40, the second pipe 41, the third pipe 42, and the fourth pipe 43.

[0025] The upstream end of the first pipe 40 in the ammonia supply direction is connected to the ammonia tank 4. The downstream end of the first pipe 40 in the ammonia supply direction is connected to the upstream end of the second pipe 41 in the ammonia supply direction.

[0026] The upstream end of the second pipe 41 in the ammonia supply direction is connected to the downstream end of the first pipe 40 in the ammonia supply direction. The downstream end of the second pipe 41 in the ammonia supply direction is connected to the upstream end of the third pipe 42 in the ammonia supply direction.

[0027] The upstream end of the third pipe 42 in the ammonia supply direction is connected to the downstream end of the second pipe 41 in the ammonia supply direction. The downstream end of the third pipe 42 in the ammonia supply direction is connected to the upstream end of the fourth pipe 43 in the ammonia supply direction.

[0028] The upstream end of the fourth pipe 43 in the ammonia supply direction is connected to the downstream end of the third pipe 42 in the ammonia supply direction. The downstream end of the fourth pipe 43 in the ammonia supply direction is connected to the plasma reactor 8.

[0029] The fourth ammonia supply path 13b supplies ammonia to the catalyst unit 9.

[0030] The upstream end of the fourth ammonia supply path 13b in the ammonia supply direction is connected to the ammonia tank 4. The downstream end of the fourth ammonia supply path 13b in the ammonia supply direction is connected to the catalyst unit 9.

[0031] The fourth ammonia supply route 13b comprises a first pipe 40, a second pipe 41, a third pipe 42, a fifth pipe 44, a sixth pipe 45, and a seventh pipe 46. In other words, the fourth ammonia supply route 13b is a route that supplies ammonia from the ammonia tank 4 to the catalyst unit 9 through the first pipe 40, the second pipe 41, the third pipe 42, the fifth pipe 44, the sixth pipe 45, and the seventh pipe 46.

[0032] The upstream end of the fifth pipe 44 in the ammonia supply direction is connected to the connection point between the downstream end of the third pipe 42 in the ammonia supply direction and the upstream end of the fourth pipe 43 in the ammonia supply direction. The downstream end of the fifth pipe 44 in the ammonia supply direction is connected to the upstream end of the sixth pipe 45 in the ammonia supply direction.

[0033] The upstream end of the sixth pipe 45 in the ammonia supply direction is connected to the downstream end of the fifth pipe 44 in the ammonia supply direction. The downstream end of the sixth pipe 45 in the ammonia supply direction is connected to the upstream end of the seventh pipe 46 in the ammonia supply direction.

[0034] The upstream end of the seventh pipe 46 in the ammonia supply direction is connected to the downstream end of the sixth pipe 45 in the ammonia supply direction. The downstream end of the seventh pipe 46 in the ammonia supply direction is connected to the catalyst unit 9.

[0035] <Mixture supply route> The mixture supply path 14 supplies a mixture containing hydrogen, nitrogen, and undecomposed ammonia from the plasma reactor 8 to the catalyst unit 9.

[0036] The upstream end of the mixture supply path 14 in the mixture supply direction is connected to the plasma reactor 8. The downstream end of the mixture supply path 14 in the mixture supply direction is connected to the catalyst unit 9.

[0037] The mixture supply path 14 comprises an eighth pipe 47, a sixth pipe 45, and a seventh pipe 46. In other words, the mixture supply path 14 is a path that supplies the mixture from the plasma reactor 8 to the catalyst unit 9 through the eighth pipe 47, the sixth pipe 45, and the seventh pipe 46.

[0038] The upstream end of the eighth pipe 47 in the mixture supply direction is connected to the plasma reactor 8. The downstream end of the eighth pipe 47 in the mixture supply direction is connected to the connection between the downstream end of the fifth pipe 44 in the ammonia supply direction and the upstream end of the sixth pipe 45 in the ammonia supply direction.

[0039] <Second Injector> The second injector 25 is interposed at the connection point between the second pipe 41 and the third pipe 42. Specifically, the upstream end of the second injector 25 is connected to the downstream end of the second pipe 41, and the downstream end of the second injector 25 is connected near the upstream end of the third pipe 42. The upstream end face of the third pipe 42 is sealed.

[0040] The second injector 25 is a fuel supply device that supplies ammonia. More specifically, the second injector 25 injects (supplies) the ammonia supplied to the second pipe 41 into the third pipe 42. In other words, the second injector 25 adjusts the amount of ammonia supplied to the plasma reactor 8 and the catalyst unit 9.

[0041] <Flow path switching valve> The flow path switching valve 26 is interposed at the connection points of the third pipe 42, the fourth pipe 43, and the fifth pipe 44.

[0042] The flow path switching valve 26 is a known three-way valve. The flow path switching valve 26 switches between the third ammonia supply path 13a and the fourth ammonia supply path 13b. This switches the supply of ammonia to the plasma reactor 8 and the supply of ammonia to the catalyst unit 9.

[0043] <Second oxygen supply pathway> The second oxygen supply path 15 supplies oxygen (air) to the catalyst unit 9.

[0044] The upstream end of the second oxygen supply path 15 in the oxygen supply direction is open to the outside (outside air). The downstream end of the second oxygen supply path 15 in the oxygen supply direction is connected to the catalyst unit 9.

[0045] The second oxygen supply path 15 comprises a ninth pipe 48 and a seventh pipe 46. In other words, the second oxygen supply path 15 is a path that supplies oxygen (air) to the catalyst unit 9 from the outside through the ninth pipe 48 and the seventh pipe 46.

[0046] The upstream end of the ninth pipe 48 in the oxygen supply direction is open to the outside (outside air). The downstream end of the ninth pipe 48 in the oxygen supply direction is connected to the connection point between the downstream end of the sixth pipe 45 in the ammonia supply direction and the upstream end of the seventh pipe 46 in the ammonia supply direction.

[0047] <Second oxygen flow control valve> The second oxygen flow control valve 27 is located midway through the oxygen supply direction of the ninth pipe 48.

[0048] The second oxygen flow control valve 27 is a flow control valve that adjusts the opening degree of the ninth pipe 48 in order to adjust the flow rate of oxygen supplied from the second oxygen supply path 15.

[0049] <Catalyst Unit> The catalyst unit 9 is connected to the hydrogen supply path 10 upstream of the oxygen sensor 6. The catalyst unit 9 burns hydrogen and oxygen, and also decomposes ammonia into hydrogen and nitrogen.

[0050] More specifically, the catalyst unit 9 is supplied with ammonia from the fourth ammonia supply path 13b and / or the mixture from the mixture supply path 14, and oxygen (air) from the second oxygen supply path 15. The catalyst unit 9 then burns the hydrogen in the mixture supplied from the mixture supply path 14 and the oxygen supplied from the second oxygen supply path 15, and / or decomposes the ammonia supplied from the fourth ammonia supply path 13b and the undecomposed ammonia in the mixture supplied from the mixture supply path 14 into hydrogen and nitrogen.

[0051] The catalyst unit 9 comprises a combustion catalyst 91 and an ammonia decomposition catalyst 92.

[0052] The combustion catalyst 91 is positioned upstream of the ammonia decomposition catalyst 92 in the ammonia supply direction (more specifically, the supply direction of a mixed gas containing hydrogen, oxygen, ammonia, and nitrogen).

[0053] The combustion catalyst 91 is a catalyst for burning hydrogen and ammonia. Examples of combustion catalysts 91 include vanadium oxide, tungsten oxide, and precious metals. Examples of precious metals include palladium, rhodium, and platinum. Precious metals may be supported by alumina, silica, zirconia, titania, etc.

[0054] The ammonia decomposition catalyst 92 is a catalyst for decomposing ammonia into hydrogen and nitrogen. In other words, the ammonia decomposition catalyst 92 decomposes ammonia and produces hydrogen. Examples of the ammonia decomposition catalyst 92 include rhodium (specifically, alumina-supported rhodium, which is alumina on which rhodium is supported).

[0055] <Mixed-fire engine> In the mixed-combustion engine 3, hydrogen, oxygen, and ammonia are mixed-combusted to drive the engine 3.

[0056] <Hydrogen supply routes> The hydrogen supply path 10 supplies hydrogen from the hydrogen production device 2 (catalyst unit 9) to the co-firing engine 3.

[0057] The upstream end of the hydrogen supply path 10 in the hydrogen supply direction is connected to the catalyst unit 9. The downstream end of the hydrogen supply path 10 in the hydrogen supply direction is connected to the co-firing engine 3.

[0058] The hydrogen supply path 10 comprises a 10th pipe 49 and an 11th pipe 50. In other words, the hydrogen supply path 10 supplies hydrogen from the catalyst unit 9 to the co-firing engine 3 through the 10th pipe 49 and the 11th pipe 50.

[0059] The upstream end of the 10th pipe 49 in the hydrogen supply direction is connected to the catalyst unit 9. The downstream end of the 10th pipe 49 in the hydrogen supply direction is connected to the upstream end of the 11th pipe 50 in the hydrogen supply direction.

[0060] The upstream end of the 11th pipe 50 in the hydrogen supply direction is connected to the downstream end of the 10th pipe 49 in the hydrogen supply direction. The downstream end of the 11th pipe 50 in the hydrogen supply direction is connected to the co-firing engine 3.

[0061] <First oxygen supply pathway> The first oxygen supply path 11 supplies oxygen (air) to the co-firing engine 3.

[0062] The upstream end of the first oxygen supply path 11 in the oxygen supply direction is open to the outside (outside air). The downstream end of the first oxygen supply path 11 in the oxygen supply direction is connected to the co-firing engine 3.

[0063] The first oxygen supply path 11 comprises a 12th pipe 51, a 13th pipe 52, and an 11th pipe 50. In other words, the first oxygen supply path 11 supplies oxygen (air) to the mixed-fire engine 3 from the outside through the 12th pipe 51, the 13th pipe 52, and the 11th pipe 50.

[0064] The upstream end of the 12th pipe 51 in the oxygen supply direction is open to the outside (outside air). The downstream end of the 12th pipe 51 in the oxygen supply direction is connected to the upstream end of the 13th pipe 52 in the oxygen supply direction.

[0065] The upstream end of the 13th pipe 52 in the oxygen supply direction is connected to the downstream end of the 12th pipe 51 in the oxygen supply direction. The downstream end of the 13th pipe 52 in the oxygen supply direction is connected to the connection between the downstream end of the 10th pipe 49 in the hydrogen supply direction and the upstream end of the 11th pipe 50 in the hydrogen supply direction.

[0066] <Ammonia Tank> Ammonia tank 4 is a tank for storing ammonia (liquid).

[0067] <Vaporizer> The vaporizer 5 is a vaporizer that vaporizes the ammonia (liquid) supplied from the ammonia tank 4.

[0068] The vaporizer 5 is located midway along the ammonia supply direction of the first pipe 40.

[0069] <First Ammonia Supply Route> The first ammonia supply route 12 supplies ammonia from the ammonia tank 4 to the co-firing engine 3.

[0070] The upstream end of the first ammonia supply path 12 in the ammonia supply direction is connected to the ammonia tank 4. The downstream end of the first ammonia supply path 12 in the ammonia supply direction is connected to the co-firing engine 3.

[0071] The first ammonia supply route 12 comprises a first pipe 40, a 14th pipe 53, a 13th pipe 52, and an 11th pipe 50. In other words, the first ammonia supply route 12 is a route for supplying ammonia from the ammonia tank 4 to the co-firing engine 3 through the first pipe 40, the 14th pipe 53, the 13th pipe 52, and the 11th pipe 50.

[0072] The upstream end of the 14th pipe 53 in the ammonia supply direction is connected to the connection point between the downstream end of the 1st pipe 40 in the ammonia supply direction and the upstream end of the 2nd pipe 41 in the ammonia supply direction. The downstream end of the 14th pipe 53 in the ammonia supply direction is connected to the connection point between the downstream end of the 12th pipe 51 in the oxygen supply direction and the upstream end of the 13th pipe 52 in the oxygen supply direction.

[0073] <Oxygen Sensor> The oxygen sensor 6 is located in the hydrogen supply path 10, in the direction of hydrogen supply. More specifically, the oxygen sensor 6 is located between the catalyst unit 9 and the check valve 20.

[0074] The oxygen sensor 6 measures the amount of oxygen emitted from the catalyst unit 9. More specifically, it measures the flow rate of unreacted oxygen that is not consumed by the combustion catalyst from the oxygen supplied from the second oxygen supply path 15.

[0075] <Check valve> The check valve 20 is located in the hydrogen supply path 10, in the direction of hydrogen supply. More specifically, the check valve 20 is located between the oxygen sensor 6 and the cooler 21.

[0076] The check valve 20 prevents oxygen (air) from flowing into the catalyst unit 9 via the hydrogen supply path 10. Specifically, by closing the check valve 20 after use of the hydrogen production device 2, the flow of oxygen (air) into the catalyst unit 9 via the hydrogen supply path 10 can be prevented.

[0077] <Cooler> The cooler 21 is interposed in the hydrogen supply direction of the hydrogen supply path 10. More specifically, the cooler 21 is interposed between the check valve 20 and the connection points of the 10th pipe 49, the 11th pipe 50, and the 13th pipe 52.

[0078] The cooler 21 cools the hydrogen in the hydrogen supply path 10. Examples of coolers 21 include known fuel coolers.

[0079] <First oxygen flow control valve> The first oxygen flow control valve 22 is interposed in the oxygen supply direction of the 12th pipe 51. More specifically, the first oxygen flow control valve 22 is interposed upstream in the oxygen supply direction of the connection portion of the 12th pipe 51, the 13th pipe 52, and the 14th pipe 53.

[0080] The first oxygen flow control valve 22 is a flow control valve that adjusts the opening degree of the 12th pipe 51 in order to adjust the flow rate of oxygen supplied from the first oxygen supply path 11.

[0081] <First Injector> The first injector 23 is interposed in the connection portion between the 14th pipe 53 and the 12th pipe 51 and the 13th pipe 52.

[0082] The first injector 23 is a fuel supply device that supplies ammonia. More specifically, the first injector 23 injects (supplies) the ammonia supplied to the 14th pipe 53 into the 13th pipe 52. In other words, the first injector 23 adjusts the amount of ammonia supplied to the mixed-fire engine 3.

[0083] <Mixture flow rate control valve> The mixture flow control valve 24 is interposed in the hydrogen supply direction of the 11th pipe 50. More specifically, the mixture flow control valve 24 is interposed between the connection point of the 10th pipe 49, the 11th pipe 50 and the 13th pipe 52 and the co-firing engine 3.

[0084] The mixture flow rate control valve 24 is a flow rate control valve that adjusts the opening degree of the 11th pipe 50 in order to adjust the flow rate of the mixture (hydrogen, oxygen, and ammonia) supplied from the hydrogen supply path 10, the first oxygen supply path 11, and the first ammonia supply path 12.

[0085] <Department Head> The control unit 7 is an electronic control unit (e.g., ECU) that performs electrical control in the engine system 1, and is composed of a microcomputer equipped with an arithmetic processing unit and memory. As shown by the dashed lines in Figure 1, the control unit 7 is electrically connected to the vaporizer 5, oxygen sensor 6, plasma reactor 8, check valve 20, cooler 21, first oxygen flow rate control valve 22, first injector 23, mixture flow rate control valve 24, second injector 25, flow path switching valve 26, second oxygen flow rate control valve 27, and pump (not shown). In other words, the control unit 7 is a control means that controls these components. The control unit 7 stores in its memory a program for operating the hydrogen production device 2 and the co-firing engine 3, as well as a program for abnormality detection control, which will be described later.

[0086] <Operation of the hydrogen production device> The operation of hydrogen production device 2 will be described in detail.

[0087] The operation of the hydrogen production device 2 is controlled by the control unit 7.

[0088] First, the control unit 7 starts the plasma reactor 8, and plasma is generated inside the plasma reactor 8.

[0089] Next, the control unit 7 controls the flow path switching valve 26 to connect the third pipe 42 and the fourth pipe 43. Then, the control unit 7 controls the vaporizer 5 and the second injector 25 to supply gaseous ammonia through the first pipe 40, the second pipe 41, the third pipe 42, and the fourth pipe 43. As a result, ammonia is supplied to the plasma reactor 8 via the third ammonia supply path 13a.

[0090] In the plasma reactor 8, a portion of the ammonia supplied to the plasma reactor 8 is decomposed into nitrogen and hydrogen. The decomposition rate of ammonia is, for example, 15% to 40%.

[0091] The mixture of the remaining ammonia (undecomposed ammonia) and hydrogen and nitrogen (hydrogen and nitrogen obtained by the decomposition of the plasma reactor 8) is then supplied to the catalyst unit 9 via the mixture supply path 14.

[0092] Furthermore, the control unit 7 controls a pump (not shown) and a second oxygen flow rate control valve 27 to supply oxygen (air) to the catalyst unit 9 via the second oxygen supply path 15.

[0093] Then, in the catalyst unit 9, hydrogen and oxygen are first combusted in the presence of the combustion catalyst 91. At this time, some ammonia is also combusted as needed. This raises the temperature inside the catalyst unit 9. When the temperature inside the catalyst unit 9 rises, the ammonia decomposition catalyst 92 acts as a catalyst. Through the catalytic action of the ammonia decomposition catalyst 92, ammonia is decomposed into hydrogen and nitrogen. This produces hydrogen.

[0094] Furthermore, once the ammonia decomposition catalyst 92 begins to perform its catalytic action, the control unit 7 stops the operation of the plasma reactor 8 and controls the flow path switching valve 26 to connect the third pipe 42 and the fifth pipe 44. As a result, ammonia is supplied to the catalyst unit 9 via the fourth ammonia supply path 13b. The ammonia is then decomposed into hydrogen and nitrogen in the catalyst unit 9.

[0095] The hydrogen produced by the hydrogen production device 2 is cooled by the cooler 21 via the hydrogen supply path 10 and then supplied to the co-firing engine 3.

[0096] The control unit 7 performs the above-described operations until a stop signal is received for the hydrogen production device 2.

[0097] <Engine System Operation> The operation of engine system 1 will be described in detail.

[0098] The engine system 1 is controlled by the control unit 7.

[0099] More specifically, following the operation of the hydrogen production apparatus 2 described above, the control unit 7 controls the first oxygen flow rate control valve 22, the first injector 23, and the mixture flow rate control valve 24. As a result, hydrogen, oxygen, and ammonia are supplied to the co-firing engine 3 from the hydrogen supply path 10, the first oxygen supply path 11, and the first ammonia supply path 12.

[0100] Furthermore, the control unit 7 controls the hydrogen production device 2, the first oxygen flow rate control valve 22, the first injector 23, and the mixture flow rate control valve 24 to adjust the amount of hydrogen, oxygen, and ammonia supplied to the co-firing engine 3 according to the requirements of the co-firing engine 3.

[0101] In the mixed-combustion engine 3, hydrogen, oxygen, and ammonia are mixed-combusted to drive the engine 3.

[0102] <Anomaly detection and control> Referring to Figure 2, the control in the engine system 1 based on oxygen detection by the oxygen sensor 6 will be explained.

[0103] First, after the co-firing engine 3 is driven, hydrogen, oxygen, and ammonia are supplied to the co-firing engine 3 as needed (S1). More specifically, the supply amounts of hydrogen, oxygen, and ammonia are controlled by the control unit 7 until the co-firing engine 3 reaches the required rotational speed. Each gas is supplied to the co-firing engine 3 from the hydrogen supply path 10, the first oxygen supply path 11, and the first ammonia supply path 12.

[0104] Next, the control unit 7 determines whether the amount of oxygen detected by the oxygen sensor 6 is above a threshold (S2). If the amount of oxygen detected is below the threshold (S2: No), the supply of gas continues in accordance with the requirements of the co-firing engine 3.

[0105] If the detected oxygen level is above a threshold (S2: Yes), the control unit 7 controls the second injector 25, and the ammonia supply amount is increased according to the detected oxygen level (for example, set value + 1%) (S3). More specifically, the increase in the discharge rate of the second injector 25 increases the amount of ammonia supplied to the catalyst unit 9 through the fourth ammonia supply path 13b. In other words, the control unit 7 increases the amount of ammonia supplied from the second ammonia supply path 13 to the catalyst unit 9 according to the increase in oxygen detected by the oxygen sensor.

[0106] Subsequently, the control unit 7 determines again whether the amount of oxygen detected by the oxygen sensor 6 is above the threshold (S4). If the amount of oxygen detected is below the threshold (S4: No), it means that the oxygen has been consumed in the combustion of ammonia due to the increase in the supply amount of ammonia. In this case, the control unit 7 learns the increase in ammonia (supply amount) (S5) and supplies ammonia according to the learned amount.

[0107] If the detected oxygen level is above the threshold (S4: Yes), then it is determined whether the ammonia supply amount (increase) is above the threshold (S6). If the ammonia supply amount is below the threshold (S6: No), the control unit 7 controls the second injector 25 again, and the ammonia supply amount increases (S3). Then, it is determined again whether the oxygen level detected by the oxygen sensor 6 is above the threshold (S4).

[0108] If the ammonia supply amount is above the threshold (S6: Yes), the control unit 7 detects an abnormality (S7). More specifically, if the oxygen detection amount is above the threshold despite an increase in the ammonia supply amount, it is determined that the combustion reaction between ammonia and oxygen is not occurring normally, and therefore the hydrogen production device 2 is malfunctioning. In other words, the control unit 7 detects an abnormality when the ammonia supply amount exceeds the threshold.

[0109] If the control unit 7 detects an abnormality, it will issue a warning through an alarm sound from an alarm device (not shown) or by displaying an alarm on a monitor or other device. This allows the user to be aware of any abnormality (malfunction) in the hydrogen production device 2.

[0110] After detecting an abnormality, the control unit 7 controls the first oxygen flow rate control valve 22, thereby suppressing the oxygen supply (S8). In other words, when the control unit 7 detects an abnormality, it suppresses the amount of oxygen supplied from the first oxygen supply path 11 to the co-firing engine 3.

[0111] Next, the control unit 7 controls the first injector 23 and / or the second injector 25 to suppress the supply of ammonia (S9). In this case, since it is sufficient to suppress the supply of ammonia to the co-firing engine 3, only one of the first injector 23 or the second injector 25 may be controlled. Alternatively, both the first injector 23 and the second injector 25 may be controlled. In other words, when the control unit 7 detects an abnormality, it suppresses the supply of oxygen supplied to the co-firing engine 3 from the first ammonia supply path 12 and / or the supply of ammonia supplied to the catalyst unit 9 from the second ammonia supply path 13.

[0112] Furthermore, the control unit 7 controls the second oxygen flow rate control valve 27, thereby controlling the amount of oxygen supplied (S10). In other words, when the control unit 7 detects an abnormality, it suppresses the amount of oxygen supplied from the second oxygen supply path 15 to the catalyst unit 9.

[0113] Furthermore, the above process suppresses the supply of ammonia and oxygen to the catalyst unit 9, thereby suppressing the amount of hydrogen produced by ammonia decomposition. In other words, when the control unit 7 detects an abnormality, it suppresses the supply of hydrogen from the hydrogen supply path 10 to the co-firing engine 3.

[0114] The above process after detecting an abnormality suppresses the supply of hydrogen, oxygen, and ammonia to the co-firing engine 3. In other words, the rotational speed of the co-firing engine 3 is suppressed. Subsequently, the control unit 7 maintains the above state (amount of gas supply) so that the vehicle can travel to the evacuation center (S11), and then the co-firing engine 3 is stopped (S12).

[0115] <Effects and Effects> According to engine system 1, it is possible to detect malfunctions in the hydrogen production equipment.

[0116] More specifically, in engine system 1, if the oxygen level detected by oxygen sensor 6 exceeds a threshold, the ammonia supply is increased. This promotes the combustion reaction between ammonia and oxygen, reducing the amount (concentration) of oxygen in the hydrogen production device. In other words, according to engine system 1, the oxygen level detected by oxygen sensor 6 will fall below the threshold, maintaining an appropriate oxygen concentration. On the other hand, according to engine system 1, if the combustion reaction between ammonia and oxygen does not proceed normally and the ammonia supply exceeds the threshold (excess), an abnormality in the hydrogen production device is detected. Therefore, according to engine system 1, a malfunction in the hydrogen production device can be detected.

[0117] Furthermore, in the engine system 1, if an abnormality is detected, the control unit 7 controls the first oxygen flow control valve 22 and the first injector 23 and / or the second injector 25. In other words, the amount of hydrogen, oxygen, and ammonia supplied to the mixed-combustion engine 3 is suppressed. As a result, the rotational speed of the mixed-combustion engine 3 decreases, allowing the vehicle to travel safely at a low speed to the evacuation center. The engine can then be shut off at the evacuation center.

[0118] Furthermore, in engine system 1, if an abnormality is detected, the second oxygen flow control valve 27 is controlled. In other words, the amount of oxygen supplied to the co-firing engine 3 can be further reduced.

[0119] Thus, according to the engine system 1, if an abnormality in the hydrogen production equipment is detected, the vehicle can be safely stopped.

[0120] <Variation> In the above embodiment, the hydrogen production device 2 operates until the co-firing engine 3 stops. However, if the supply of hydrogen to the co-firing engine 3 is no longer needed, the hydrogen production device 2 may be stopped even while the co-firing engine 3 is running.

[0121] After the hydrogen production device 2 is stopped (after use), the second oxygen flow rate control valve 27 and the check valve 20 are closed. This prevents oxygen (air) from entering the catalyst unit 9 via the second oxygen supply path 15 and the hydrogen supply path 10. As a result, oxidation of the combustion catalyst 91 and the ammonia decomposition catalyst 92 can be suppressed. Even during use, oxidation of the combustion catalyst 91 and the ammonia decomposition catalyst 92 can be suppressed by adjusting the second oxygen flow rate control valve 27 and the check valve 20.

[0122] Furthermore, when the check valve 20 is closed, the supply of gas from the hydrogen production device 2 to the co-firing engine 3 is stopped. Therefore, the co-firing engine 3 is driven by co-firing oxygen supplied from the first oxygen supply path 11 and ammonia supplied from the first ammonia supply path 12. [Explanation of Symbols]

[0123] 1. Engine System 2. Hydrogen production equipment 3. Mixed-fire engine 6. Oxygen Sensor 9. Catalytic Unit 10. Hydrogen supply routes 11. First oxygen supply pathway 12. First Ammonia Supply Route 13. Second Ammonia Supply Route 15. Second oxygen supply pathway 91 Combustion catalyst 92 Ammonia decomposition catalyst

Claims

1. A hydrogen production device that produces hydrogen, A co-combustion engine that burns hydrogen, oxygen, and ammonia together, A hydrogen supply path that supplies hydrogen from the hydrogen production apparatus to the co-firing engine, A first oxygen supply path that supplies oxygen to the aforementioned co-firing engine, A first ammonia supply path that supplies ammonia to the aforementioned co-firing engine, An oxygen sensor interposed in the hydrogen supply path, It includes control means for controlling these, The hydrogen production apparatus, A catalyst unit comprising a combustion catalyst for burning ammonia and an ammonia decomposition catalyst for decomposing ammonia and producing hydrogen, A second ammonia supply path for supplying ammonia to the catalyst unit, The catalyst unit is further provided with a second oxygen supply path that supplies oxygen to the catalyst unit, The catalyst unit is connected to the hydrogen supply path upstream of the oxygen sensor. The control means is In accordance with the increase in oxygen detected by the oxygen sensor, the amount of ammonia supplied from the second ammonia supply path to the catalyst unit is increased. An engine system that detects an abnormality when the supply amount of ammonia exceeds a threshold.

2. Furthermore, when the control means detects an abnormality, The amount of oxygen supplied from the first oxygen supply pathway is suppressed. The engine system according to claim 1, wherein the amount of ammonia supplied from the first and / or second ammonia supply path is suppressed.

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