JP2020147475A - Reforming system - Google Patents

Abstract

To provide a reforming system in which the amount of fuel gas passing through a reforming unit at start-up can be reduced.SOLUTION: A reforming system 10 comprises a reformer 22 reforming ammonia gas to produce reformed gas containing hydrogen, a gas supply flow channel 14 in which air supplied to the reformer 22 flows, a fuel supply unit 28 supplying the ammonia gas to the reformer 22 through the gas supply flow channel 14, a reformed gas flow channel 17 in which the reformed gas produced by the reformer flows, an electric heater 21 having a heat generating element 23 arranged upstream of the reformer 22 in the gas supply flow channel 14, a housing 25 for housing the reformer 22 and the heat generating element 23, an upstream side on-off valve 19 opening/closing the gas supply flow channel 14, and a downstream side on-off valve 20 opening/closing the reformed gas flow channel 17. The reformer 22 is arranged above the heat generating element 23 in the housing 25.SELECTED DRAWING: Figure 2

Description

The present invention relates to a reforming system.

As a conventional reforming system, for example, the technique described in Patent Document 1 is known. The reforming system described in Patent Document 1 includes an evaporator that vaporizes liquid ammonia, a decomposer that decomposes ammonia vaporized by this evaporator to generate hydrogen, and gaseous ammonia from the evaporator to the decomposer. It is provided with an ammonia supply pipe for supplying the gas, an inflow pipe for supplying air to the decomposer, and an outflow pipe through which hydrogen generated by the decomposer flows.

Japanese Unexamined Patent Publication No. 2014-21115

However, the above-mentioned prior art has the following problems. That is, when the reforming system is started, ammonia (fuel gas) is not stably burned in the cracker until the warming up of the cracker (reformer) is completed. In addition, when the decomposer is warmed up, it is necessary to supply only ammonia to the decomposer or supply ammonia to the decomposer in a state rich in air in order to prevent abnormal oxidation of the catalyst of the decomposer. .. Therefore, ammonia will slip through the decomposer until the warming up of the decomposer is completed. Therefore, a device for post-treatment of ammonia is required.

An object of the present invention is to provide a reforming system capable of reducing the amount of fuel gas that passes through the reforming section at startup.

The reforming system according to one aspect of the present invention has a reforming catalyst that decomposes the fuel gas into hydrogen, reforms the fuel gas to generate a reformed gas containing hydrogen, and reforms. A gas supply flow path through which the oxidizing gas supplied to the section flows, a fuel supply section that supplies fuel gas to the reforming section through the gas supply flow path, and a reforming gas through which the reforming gas generated by the reforming section flows. A first that opens and closes the flow path, the heater part having a heating element arranged on the upstream side of the gas supply flow path from the reforming part, the housing accommodating the reforming part and the heating element, and the gas supply flow path. It includes an on-off valve, a second on-off valve that opens and closes the reformed gas flow path, and a control unit that controls a fuel supply unit, a heater unit, a first on-off valve, and a second on-off valve. The control unit is arranged above the heating element in the above, and after executing the first control process for controlling the heater unit so as to energize the heating element with the first on-off valve and the second on-off valve closed. , A second control process that controls the fuel supply unit, the first on-off valve, and the second on-off valve so as to supply the fuel gas and the oxidizing gas to the reforming unit with the first on-off valve and the second on-off valve open. To execute.

In such a reforming system, when the first on-off valve and the second on-off valve are closed, the flow path between the first on-off valve and the second on-off valve is closed, and the fuel in the flow path is closed. No gas flow occurs. Therefore, when the heating element of the heater unit is energized with the first opening / closing valve and the second opening / closing valve closed when the reforming system is started, an updraft is generated due to the heat generated by the heating element. Here, the reforming portion is arranged above the heating element in the housing. Therefore, the reformed portion is warmed by the heat of the updraft. By warming the reforming section using the updraft generated by the heat generated by the heating element in this way, it is necessary to supply fuel gas to the reforming section in order to transfer the heat of the heating element to the reforming section through the fuel gas. Absent. This reduces the amount of fuel gas that slips through the reforming section when the reforming system is started.

The reforming portion may be arranged at a position directly above the heating element in the housing. In such a configuration, the reformed portion can be efficiently warmed by effectively utilizing the updraft generated by the heat generated by the heating element.

The gas supply flow path has a pipe connected to the housing, and at least a part of the pipe may be arranged below the housing. The gas existing in the flow path between the first on-off valve and the second on-off valve may contain components such as hydrogen and oxygen in addition to the fuel. The specific gravity of oxygen is higher than that of fuel and hydrogen. Therefore, even if oxygen is contained in the gas existing in the flow path between the first on-off valve and the second on-off valve when the first on-off valve and the second on-off valve are closed, the inside of the pipe Oxygen will be accumulated below the housing in. Therefore, oxygen is less likely to be present in the housing, and oxidative deterioration of the reforming catalyst in the reforming portion is prevented.

The reforming system further includes a temperature detecting unit that detects the temperature of the reforming unit, and when the control unit executes the second control process, the temperature of the reforming unit detected by the temperature detecting unit is predetermined. When the temperature exceeds the specified temperature, the fuel supply unit, the first on-off valve and the second on-off valve are opened so as to supply the fuel gas and the oxidizing gas to the reforming part with the first on-off valve and the second on-off valve open. You may control it. In such a configuration, by detecting the temperature of the reforming section, it is easy to properly time the fuel gas and the oxidizing gas to be supplied to the reforming section with the first on-off valve and the second on-off valve open. You can judge.

A flow rate control valve for controlling the flow rate of the oxidizing gas supplied to the reforming unit is provided in the gas supply flow path, and the control unit uses the first on-off valve and the first on-off valve when executing the second control process. The fuel supply unit and the flow rate control valve may be controlled so as to supply the fuel gas and the oxidizing gas to the reforming unit while controlling the opening of the second on-off valve. In such a configuration, since the first on-off valve that opens and closes the gas supply flow path and the flow rate control valve that controls the flow rate of the oxidizing gas supplied to the reforming portion are separate valves, the gas supply flow path It becomes easier to control the opening and closing and the supply amount of oxidizing gas.

According to the present invention, it is possible to reduce the amount of fuel gas that passes through the reformed portion at startup.

It is a schematic block diagram which shows the engine system provided with the reforming system which concerns on one Embodiment of this invention. It is a figure which shows the height positional relationship of the reformer, a gas supply flow path and a reforming gas flow path shown in FIG. It is a block diagram which shows the structure of the control system of the engine system shown in FIG. FIG. 5 is a flowchart showing details of a control processing procedure executed by the start control unit shown in FIG. FIG. 5 is a flowchart showing details of a control processing procedure executed by the stop control unit shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an engine system including a reforming system according to an embodiment of the present invention. In FIG. 1, the engine system 1 is mounted on a vehicle. The engine system 1 includes an ammonia engine 2, an intake passage 3, an exhaust passage 4, a main injector 5, and a main throttle valve 6.

The ammonia engine 2 is an engine that uses ammonia (NH ₃ ) as fuel. The ammonia engine 2 is, for example, a 4-cylinder engine having four combustion chambers. Hydrogen is supplied to the ammonia engine 2 together with ammonia (described later).

The intake passage 3 is connected to the ammonia engine 2. The intake passage 3 is a passage through which the air supplied to the ammonia engine 2 flows. An air cleaner 7 for removing dust and foreign matter such as dust contained in the air is provided in the intake passage 3.

The exhaust passage 4 is connected to the ammonia engine 2. The exhaust passage 4 is a passage through which the exhaust gas generated from the combustion chamber of the ammonia engine 2 flows. An exhaust purification catalyst 8 for removing harmful substances such as nitrogen oxides (NOx) and ammonia contained in the exhaust gas is arranged in the exhaust passage 4. As the exhaust gas purification catalyst 8, for example, a three-way catalyst, an SCR (Selective Catalytic Reduction) catalyst, or the like is used.

The main injector 5 is an electromagnetic type fuel injection valve for injecting ammonia gas (NH ₃ gas) is a fuel gas toward the ammonia engine 2. The main injector 5 injects ammonia gas between the main throttle valve 6 and the ammonia engine 2 in the intake passage 3. The main injector 5 is connected to a vaporizer 12 described later via an ammonia flow path 9.

The main throttle valve 6 is arranged between the air cleaner 7 and the ammonia engine 2 in the intake passage 3. The main throttle valve 6 is an electromagnetic flow rate control valve that controls the flow rate of air supplied to the ammonia engine 2.

Further, the engine system 1 includes the reforming system 10 of the present embodiment. The reforming system 10 includes an ammonia tank 11, a vaporizer 12, a reforming device 13, a gas supply flow path 14, a reforming throttle valve 15, a reforming injector 16, a reforming gas flow path 17. It includes a cooler 18, an upstream opening / closing valve 19, and a downstream opening / closing valve 20.

The ammonia tank 11 is a tank that stores ammonia in a liquid state. The vaporizer 12 vaporizes the liquid ammonia stored in the ammonia tank 11 to generate ammonia gas.

The reformer 13 has an electric heater 21 and a reformer 22. The electric heater 21 is a heater unit that raises the temperature of the reformer 22. The electric heater 21 has, for example, a heating element 23 having a honeycomb structure, and a power supply 24 connected to the heating element 23 via an electrode terminal (not shown) to energize the heating element 23. When the heating element 23 is energized by the power supply 24, the heating element 23 generates heat.

The reformer 22 is a reforming unit that reforms ammonia gas to generate a reformed gas containing hydrogen. The reformer 22 has, for example, a carrier 22a exhibiting a honeycomb structure. The carrier 22a is coated with a reforming catalyst 22b that decomposes ammonia gas into hydrogen. The reforming catalyst 22b has a function of burning ammonia gas in addition to a function of decomposing ammonia gas into hydrogen. As the reforming catalyst 22b, for example, ruthenium, palladium, rhodium, platinum or the like is used.

As shown in FIG. 2, the reformer 13 has a cylindrical housing 25 that houses the heating element 23 of the electric heater 21 and the reformer 22. Although not particularly shown, the power supply 24 of the electric heater 21 is arranged outside the housing 25, for example. The housing 25 is made of a metal (for example, stainless steel) having corrosion resistance to ammonia gas and reformed gas.

The heating element 23 is arranged on the upstream side of the gas supply flow path 14 with respect to the reformer 22 in the housing 25. The reformer 22 is arranged above the heating element 23 in the housing 25. The upper side here corresponds to the opposite side in the direction of gravity (the G direction in FIG. 2). Specifically, the reformer 22 is arranged at a position directly above (directly above) the heating element 23 in the housing 25. The position directly above the heating element 23 is the position above the heating element 23 in the vertical direction.

The gas supply passage 14 connects the intake passage 3 and the reformer 22. Specifically, one end of the gas supply flow path 14 is branched and connected to a portion of the intake passage 3 between the air cleaner 7 and the main throttle valve 6. The other end of the gas supply flow path 14 is connected to the reformer 22. The gas supply flow path 14 is a flow path through which air, which is an oxidizing gas supplied to the reformer 22, flows.

As shown in FIG. 2, the gas supply flow path 14 includes a gas supply pipe 26 that connects the intake passage 3 and the lower end of the housing 25, a lower end of the housing 25 in the housing 25, and a reformer 22. It consists of a space 25a between them. The gas supply pipe 26 is arranged below the housing 25. The lower side here corresponds to the direction of gravity (the G direction in FIG. 2). The gas supply pipe 26 has a pipe portion 26a extending directly below (directly below) from the lower end of the housing 25, and a pipe portion 26b extending horizontally from the lower end of the pipe portion 26a. The horizontal direction is a direction orthogonal to the direction of gravity.

The reforming throttle valve 15 is arranged in the gas supply pipe 26 of the gas supply flow path 14. The reforming throttle valve 15 is an electromagnetic flow rate control valve that controls the flow rate of air supplied to the reformer 22.

The reforming injector 16 is connected to the vaporizer 12 via an ammonia flow path 27. The reforming injector 16 is an electromagnetic fuel injection valve that injects ammonia gas, which is a fuel gas, toward the reformer 22. The reforming injector 16 injects ammonia gas between the reforming throttle valve 15 and the reforming device 13 in the gas supply flow path 14. The ammonia tank 11, the vaporizer 12, the ammonia flow path 27, and the reforming injector 16 form a fuel supply unit 28 that supplies ammonia gas to the reformer 22 through the gas supply flow path 14.

The reforming gas flow path 17 connects the reformer 22 and the intake passage 3. Specifically, one end of the reforming gas flow path 17 is connected to the reformer 22. The other end of the reformed gas flow path 17 is branched and connected to a portion of the intake passage 3 between the main throttle valve 6 and the ammonia engine 2. The reformed gas flow path 17 is a flow path through which the reformed gas generated by the reformer 22 flows.

As shown in FIG. 2, the reformed gas flow path 17 includes a reformed gas pipe 29 connecting the intake passage 3 and the upper end of the housing 25, the upper end of the housing 25 in the housing 25, and the reformer. It consists of a space 25b between 22 and 22. The reforming gas pipe 29 includes a pipe portion 29a extending directly upward from the upper end of the housing 25, a pipe portion 29b bent in an L shape from the upper end of the pipe portion 29a and extending downward, and the pipe portion 29b. It has a pipe portion 29c extending in the horizontal direction from the lower end. The pipe portion 29c is arranged at the same height as the pipe portion 26b of the gas supply pipe 26, for example.

The cooler 18 is arranged in the reformed gas flow path 17. Specifically, as shown in FIG. 2, the cooler 18 is arranged in the pipe portion 29b of the reformed gas pipe 29. The cooler 18 cools the reformed gas supplied to the ammonia engine 2. The cooler 18 cools the reformed gas by, for example, heat exchange with the engine cooling water. By cooling the reformed gas with the cooler 18, the volume expansion of the reformed gas is suppressed, so that the reformed gas easily enters the combustion chamber of the ammonia engine 2.

The upstream opening / closing valve 19 is arranged between the reforming throttle valve 15 and the reforming device 13 in the gas supply flow path 14. More specifically, the upstream on-off valve 19 is arranged between the reforming injector 16 and the reforming device 13 in the gas supply flow path 14. The upstream opening / closing valve 19 is an electromagnetic first opening / closing valve that opens / closes the gas supply flow path 14. As shown in FIG. 2, the upstream opening / closing valve 19 is arranged in the pipe portion 26b of the gas supply pipe 26.

The downstream opening / closing valve 20 is arranged in the reformed gas flow path 17. Specifically, the downstream opening / closing valve 20 is arranged between the cooler 18 and the intake passage 3 in the reformed gas flow path 17. The downstream opening / closing valve 20 is an electromagnetic second opening / closing valve that opens / closes the reformed gas flow path 17. As shown in FIG. 2, the downstream opening / closing valve 20 is arranged in the pipe portion 29c of the reformed gas pipe 29.

Further, the reforming system 10 includes a temperature sensor 30 and a controller 31. The temperature sensor 30 is a temperature detection unit that detects the temperature of the reformer 22. The temperature sensor 30 detects, for example, the temperature of the reforming catalyst 22b of the reformer 22.

The controller 31 is composed of a CPU, RAM, ROM, an input / output interface, and the like. The ignition switch 32 (IG switch) and the starter motor 33 are connected to the controller 31. The ignition switch 32 is a manually operated switch for instructing the driver of the vehicle to start and stop the ammonia engine 2. The starter motor 33 is a motor for starting the ammonia engine 2.

As shown in FIG. 3, the controller 31 has a start control unit 34 and a stop control unit 35.

When the ammonia engine 2 is started, the start control unit 34 has the main injector 5, the main throttle valve 6, the reforming throttle valve 15, and the fuel supply unit 28 based on the operation signal of the ignition switch 32 and the detected value of the temperature sensor 30. Controls the reforming injector 16, the power supply 24 of the electric heater 21, the upstream opening / closing valve 19, the downstream opening / closing valve 20, and the starter motor 33.

The start control unit 34 executes a first control process for controlling the power supply 24 so as to energize the heating element 23 of the electric heater 21 with the upstream opening / closing valve 19 and the downstream opening / closing valve 20 closed, and then the upstream side. A reforming injector 16, a reforming throttle valve 15, an upstream opening / closing valve 19 and a downstream opening / closing valve 20 so as to supply ammonia gas and air to the reformer 22 with the on-off valve 19 and the downstream on-off valve 20 open. The second control process for controlling the above is executed.

When the start control unit 34 executes the second control process, when the temperature of the reformer 22 detected by the temperature sensor 30 becomes equal to or higher than a predetermined predetermined temperature, the upstream open / close valve 19 and the downstream open / close valve 20 is controlled to open, and the reforming injector 16 and the reforming throttle valve 15 are controlled so as to supply ammonia gas and air to the reformer 22.

When the ammonia engine 2 is stopped, the stop control unit 35 sets the main injector 5, the main throttle valve 6, the reforming throttle valve 15, the reforming injector 16, the upstream opening / closing valve 19 and the downstream based on the operation signal of the ignition switch 32. Controls the side open / close valve 20.

FIG. 4 is a flowchart showing details of a control processing procedure executed by the start control unit 34. Before the execution of this process, the main injector 5, the main throttle valve 6, the reforming throttle valve 15, and the reforming injector 16 are in a closed state with the upstream opening / closing valve 19 and the downstream opening / closing valve 20 closed.

In FIG. 4, the start control unit 34 first determines whether or not the ignition switch 32 has been turned ON based on the operation signal of the ignition switch 32 (procedure S101). When the start control unit 34 determines that the ignition switch 32 has been turned on, the start control unit 34 controls the power supply 24 so as to energize the heating element 23 of the electric heater 21 (procedure S102).

Subsequently, the start control unit 34 determines whether or not the temperature of the reformer 22 is equal to or higher than the specified temperature based on the detected value of the temperature sensor 30 (procedure S103). The specified temperature is a temperature at which ammonia gas can be burned, and is, for example, about 200 ° C. When the start control unit 34 determines that the temperature of the reformer 22 is equal to or higher than the specified temperature, the start control unit 34 controls the power supply 24 so as to stop the energization of the heating element 23 (procedure S104).

Then, the start control unit 34 controls to open the upstream opening / closing valve 19 and controls to open the downstream opening / closing valve 20 (procedure S105). Then, the start control unit 34 controls the reforming throttle valve 15 to open, and controls the reforming injector 16 so as to inject ammonia gas from the reforming injector 16 (procedure S106). As a result, ammonia gas and air are supplied to the reformer 22.

Subsequently, the start control unit 34 controls the starter motor 33 so as to crank the ammonia engine 2 (procedure S107). As a result, the ammonia engine 2 is started. Then, the start control unit 34 controls to open the main throttle valve 6 (procedure S108). As a result, air is supplied to the ammonia engine 2. Then, the start control unit 34 controls the main injector 5 so as to inject ammonia gas from the main injector 5 (procedure S109). As a result, ammonia gas is supplied to the ammonia engine 2.

Here, the procedures S101 and S102 function as the first control process described above. Steps S103 to S106 function as the second control process described above.

FIG. 5 is a flowchart showing details of a control processing procedure executed by the stop control unit 35. Before the execution of this process, the main injector 5, the main throttle valve 6, the reforming throttle valve 15, and the reforming injector 16 are in an open state with the upstream opening / closing valve 19 and the downstream opening / closing valve 20 open.

In FIG. 5, the stop control unit 35 first determines whether or not the ignition switch 32 has been turned off based on the operation signal of the ignition switch 32 (procedure S111). When the stop control unit 35 determines that the ignition switch 32 has been turned off, the stop control unit 35 controls the main injector 5 so as to stop the injection of ammonia gas from the main injector 5 (procedure S112). As a result, the supply of ammonia gas to the ammonia engine 2 is stopped. Then, the stop control unit 35 controls to close the main throttle valve 6 (procedure S113). As a result, the supply of air to the ammonia engine 2 is stopped.

Subsequently, the stop control unit 35 controls to close the reforming throttle valve 15 (procedure S114). As a result, the supply of air to the reformer 22 is stopped. Then, the stop control unit 35 controls the reforming injector 16 so as to stop the injection of the ammonia gas from the reforming injector 16 (procedure S115). As a result, the supply of ammonia gas to the reformer 22 is stopped.

Subsequently, the stop control unit 35 controls to close the upstream opening / closing valve 19 and also controls to close the downstream opening / closing valve 20 (procedure S116).

In the engine system 1 as described above, if the ignition switch 32 is turned off while the ammonia engine 2 is operating, the supply of ammonia gas and air to the ammonia engine 2 is stopped. Then, the supply of air and ammonia gas to the reformer 22 is stopped. Then, the upstream opening / closing valve 19 and the downstream opening / closing valve 20 are closed. As a result, the ammonia engine 2 is stopped.

At this time, the flow path between the upstream opening / closing valve 19 and the downstream opening / closing valve 20 becomes a closed flow path C closed by the upstream opening / closing valve 19 and the downstream opening / closing valve 20 (see FIG. 2). Specifically, the closed flow path C is a region between the upstream opening / closing valve 19 and the housing 25 inside the gas supply pipe 26, a housing inside the housing 25, and a housing inside the reformed gas pipe 29. It is formed by a region between the body 25 and the downstream opening / closing valve 20. The inside of the closed flow path C is sealed.

The closed flow path C is filled with ammonia gas in a rich state. Specifically, the closed flow path C is filled with 100% ammonia gas, or is filled with ammonia gas at a high concentration so that oxidation of ammonia does not occur. Ammonia gas does not flow in the closed flow path C.

After that, when the ignition switch 32 is turned ON in order to restart the ammonia engine 2, the heating element 23 of the electric heater 21 is energized and the heating element 23 generates heat. Then, as shown in FIG. 2, an updraft is generated in the heating element 23. The updraft is the flow of the atmosphere upward in the vertical direction. A reformer 22 is arranged directly above the heating element 23. Therefore, the updraft reaches the reformer 22, and the heat of the updraft is transferred to the reformer 22. Therefore, the reformer 22 is warmed by the heat of the updraft, and the reformer 22 rises in temperature.

Then, when the temperature of the reformer 22 reaches the specified temperature, the energization of the heating element 23 is stopped, and the upstream opening / closing valve 19 and the downstream opening / closing valve 20 are opened. Then, the reforming throttle valve 15 opens and the reforming injector 16 injects ammonia gas to supply air and ammonia gas to the reformer 22.

Then, the reforming catalyst 22b of the reformer 22 ignites and burns the ammonia gas, and the heat of combustion further raises the temperature of the reformer 22. Specifically, as shown in the following formula, a chemical reaction (oxidation reaction) occurs between a part of ammonia and oxygen in the air, so that a combustion reaction of ammonia occurs and combustion heat is generated.
NH ₃ + 3/4O ₂ → 1 / 2N ₂ + 3 / 2H ₂ O + Q

Then, when the reformer 22 reaches a temperature at which the reformer 22 can reform the ammonia gas (for example, about 300 ° C. to 400 ° C.), the reformer 22b of the reformer 22 starts reforming the ammonia gas, and hydrogen is generated. A reformed gas containing the above is produced. Specifically, as shown in the following formula, a reforming reaction occurs in which ammonia is decomposed into hydrogen and nitrogen by the heat of combustion of ammonia, and a reforming gas containing hydrogen and nitrogen is generated.
NH ₃ → 3 / 2H ₂ + 1 / 2N ₂ −Q

When the reformer 22 produces a reformed gas in a hydrogen-rich state, the starter motor 33 starts the ammonia engine 2. Then, when the main throttle valve 6 is opened, air is supplied to the ammonia engine 2. Then, the reformed gas burns in the combustion chamber of the ammonia engine 2. Then, the ammonia gas is supplied to the ammonia engine 2 by injecting the ammonia gas from the main injector 5. As a result, the ammonia gas burns together with the hydrogen in the reformed gas in the combustion chamber of the ammonia engine 2. Therefore, the engine system 1 is in steady operation after the warming up of the reformer 22 is completed.

As described above, in the present embodiment, when the upstream opening / closing valve 19 and the downstream opening / closing valve 20 are closed, the flow path between the upstream opening / closing valve 19 and the downstream opening / closing valve 20 is closed. , No flow of ammonia gas occurs in the flow path. Therefore, when the heating element 23 of the electric heater 21 is energized with the upstream opening / closing valve 19 and the downstream opening / closing valve 20 closed when the engine system 1 is started, an updraft is generated due to the heat generated by the heating element 23. Here, the reformer 22 is arranged above the heating element 23 in the housing 25. Therefore, the reformer 22 is warmed by the heat of the updraft. By warming the reformer 22 by utilizing the updraft generated by the heat generated by the heating element 23 in this way, the ammonia gas is transferred to the reformer 22 in order to transfer the heat of the heating element 23 to the reformer 22 through the ammonia gas. There is no need to supply. As a result, the amount of ammonia gas that passes through the reformer 22 when the engine system 1 is started is reduced.

As a result, the post-treatment of the ammonia gas discharged to the outside of the engine system 1 becomes unnecessary, so that the physique of the exhaust gas purification catalyst 8 as the post-treatment device can be reduced. Further, it is not necessary to provide an adsorber or the like for adsorbing ammonia as another post-treatment device. Further, the reformer 22 can be warmed without using a special component or the like for transferring heat to the reformer 22. As described above, it is possible to reduce the cost of the engine system 1.

Further, in the present embodiment, the reformer 22 is arranged at a position directly above the heating element 23 in the housing 25. Therefore, the reformer 22 can be efficiently warmed by effectively utilizing the updraft generated by the heat generated by the heating element 23.

Further, in the present embodiment, the gas supply flow path 14 has a gas supply pipe 26 connected to the housing 25, and the gas supply pipe 26 is arranged below the housing 25. The gas existing in the flow path between the upstream opening / closing valve 19 and the downstream opening / closing valve 20 may contain hydrogen, oxygen, nitrogen and water in addition to ammonia. The specific gravity of oxygen is higher than the specific gravity of ammonia, hydrogen, nitrogen and water. Therefore, when the upstream opening / closing valve 19 and the downstream opening / closing valve 20 are closed, oxygen is contained in the gas existing in the flow path between the upstream opening / closing valve 19 and the downstream opening / closing valve 20. However, oxygen will be accumulated below the housing 25 in the gas supply pipe 26. Therefore, since oxygen is less likely to be present in the housing 25, oxidative deterioration of the reforming catalyst 22b of the reformer 22 is prevented.

Further, in the present embodiment, by detecting the temperature of the reformer 22, the appropriate timing for supplying ammonia gas and air to the reformer 22 with the upstream opening / closing valve 19 and the downstream opening / closing valve 20 open. Can be easily determined.

Further, in the present embodiment, the upstream opening / closing valve 19 that opens / closes the gas supply flow path 14 and the reforming throttle valve 15 that controls the flow rate of the air supplied to the reformer 22 are separate valves, so that the gas It becomes easier to control the opening / closing of the supply flow path 14 and the amount of air supplied.

Further, in the present embodiment, by warming the reformer 22 by utilizing the updraft generated by the heat generated by the heating element 23, only ammonia gas is not supplied to the reformer 22 when the engine system 1 is started, so that the starter is used. The motor 33 does not have to immediately crank the ammonia engine 2. Therefore, the energy saving of the engine system 1 can be achieved.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the reformer 22 is arranged at a position directly above the heating element 23 in the housing 25, but the position of the reformer 22 is not particularly limited to that form and generates heat. As long as it is above the body 23, it may be located diagonally above the heating element 23.

Further, in the above embodiment, the gas supply pipe 26 is arranged below the housing 25 as a whole, but the present invention is not particularly limited to that form, and only a part of the gas supply pipe 26 is below the housing 25. May also be located on the lower side. Further, when the amount of oxygen contained in the gas existing in the flow path between the upstream opening / closing valve 19 and the downstream opening / closing valve 20 is extremely small, the gas supply pipe 26 is below the housing 25. It does not have to be placed in.

Further, in the above embodiment, the timing of opening the upstream opening / closing valve 19 and the downstream opening / closing valve 20 is controlled based on the detected value of the temperature sensor 30, but the embodiment is not particularly limited. For example, since the temperature of the reformer 22 can be estimated from the flow rate of ammonia gas, the flow rate of air, the time, the room temperature, etc., the upstream opening / closing valve is based on the time since the ignition switch 32 is turned on. The timing of opening 19 and the downstream opening / closing valve 20 may be controlled.

Further, in the above embodiment, the downstream opening / closing valve 20 is arranged between the cooler 18 and the intake passage 3 in the reformed gas flow path 17, but is not particularly limited to that form. For example, when the downstream opening / closing valve 20 has high heat resistance, the downstream opening / closing valve 20 may be arranged between the reformer 13 and the cooler 18 in the reforming gas flow path 17.

Further, in the above embodiment, when the ammonia engine 2 is stopped, the reforming injector 16 stops the injection of ammonia gas from the reforming injector 16 after the reforming throttle valve 15 is controlled to close. It is controlled, but not particularly limited to its form. If the inside of the closed flow path C closed by the upstream opening / closing valve 19 and the downstream opening / closing valve 20 becomes ammonia-rich after the ammonia engine 2 is stopped, the valve closing control and reforming of the reforming throttle valve 15 are performed. Ammonia gas injection stop control from the injector 16 may be performed at the same time.

Further, in the above embodiment, the reforming throttle valve 15 for controlling the flow rate of air is provided, but the reforming throttle valve 15 may not be particularly provided. In this case, the upstream opening / closing valve 19 that opens / closes the gas supply flow path 14 functions to control the air flow. Therefore, the number of valves can be reduced, and the configuration of the reforming system 10 can be simplified.

Further, although the reforming system 10 of the above embodiment is provided in the engine system 1, the present invention is not particularly limited to the engine system, and can be applied to, for example, a turbine system or a fuel cell system. Further, the fuel gas is not particularly limited to ammonia gas, and hydrocarbon gas or the like may be used. Further, the oxidizing gas is not particularly limited to air, and oxygen may be used.

10 ... reforming system, 14 ... gas supply flow path, 15 ... reforming throttle valve (flow control valve), 17 ... reforming gas flow path, 19 ... upstream side on-off valve (first on-off valve), 20 ... downstream side On-off valve (second on-off valve), 21 ... electric heater (heater part), 22 ... reformer (modifying part), 22b ... reforming catalyst, 23 ... heating element, 25 ... housing, 26 ... gas supply piping (Piping), 28 ... Fuel supply unit, 30 ... Temperature sensor (temperature detection unit), 34 ... Start control unit (control unit).

Claims (5)

A reforming unit having a reforming catalyst that decomposes the fuel gas into hydrogen and reforming the fuel gas to generate the reforming gas containing hydrogen.
A gas supply flow path through which the oxidizing gas supplied to the reformer flows, and
A fuel supply unit that supplies the fuel gas to the reforming unit through the gas supply flow path,
A reformed gas flow path through which the reformed gas generated by the reformed portion flows,
A heater part having a heating element arranged on the upstream side of the gas supply flow path from the reforming part,
A housing that houses the modified part and the heating element,
A first on-off valve that opens and closes the gas supply flow path,
A second on-off valve that opens and closes the reformed gas flow path,
A fuel supply unit, a heater unit, a first on-off valve, and a control unit for controlling the second on-off valve are provided.
The reforming portion is arranged above the heating element in the housing.
The control unit executes the first control process for controlling the heater unit so as to energize the heating element with the first on-off valve and the second on-off valve closed, and then the first on-off valve and the first on-off valve. A second control that controls the fuel supply unit, the first on-off valve, and the second on-off valve so as to supply the fuel gas and the oxidizing gas to the reforming unit with the second on-off valve open. A reforming system that performs the process. The reforming system according to claim 1, wherein the reforming portion is arranged at a position directly above the heating element in the housing. The gas supply flow path has a pipe connected to the housing and has a pipe.
The reforming system according to claim 1 or 2, wherein at least a part of the pipe is arranged below the housing. A temperature detection unit for detecting the temperature of the reforming unit is further provided.
When the control unit executes the second control process, when the temperature of the reforming unit detected by the temperature detection unit becomes equal to or higher than a predetermined predetermined temperature, the first on-off valve and the second opening / closing valve and the second Claims 1 to 3 that control the fuel supply unit, the first on-off valve, and the second on-off valve so as to supply the fuel gas and the oxidizing gas to the reforming unit with the on-off valve open. The reforming system according to any one item. A flow rate control valve for controlling the flow rate of the oxidizing gas supplied to the reforming unit is provided in the gas supply flow path.
When the second control process is executed, the control unit controls to open the first on-off valve and the second on-off valve, and supplies the fuel gas and the oxidizing gas to the reforming unit. The reforming system according to any one of claims 1 to 4, wherein the fuel supply unit and the flow rate control valve are controlled so as to be used.

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