JP2018076214A - Hydrogen generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen generator which can improve a reformation ability of a reformer.SOLUTION: A hydrogen generator 1 comprises a reaction part 10 which contains reaction material 14, which generates heat by chemical reaction with ammonia supplied from an ammonia tank 2 and releases ammonia when heat is provided, a heat exchange part 11 which heats ammonia by the heat generated by the reaction material 14 and, transfers heat to the reaction material 14, piping 16 and 6 which supplies ammonia heated by the heat exchange part 11 to a reformation catalyst 4, an on-off valve 17 which opens and closes a flow channel for supplying ammonia from the ammonia tank 2 to the reaction part 10, an on-off valve 18 which opens and closes a flow channel for supplying ammonia from the ammonia tank 2 to the reformation catalyst 4, and a valve control part 21 which directs the on-off valve 17 to open and the on-off valve 18 to close at start-up, and also directs the on-off valve 17 to close and the on-off valve 18 to open during a normal operation after the start-up.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydrogen generator.

As a conventional hydrogen generator, for example, an apparatus described in Patent Document 1 is known. The apparatus described in Patent Document 1 is a mixture of an ammonia (NH ₃ ) tank, a vaporizer that vaporizes ammonia supplied from the ammonia tank, and vaporized fuel and air from the vaporizer, and reforms the fuel. A reformer that generates gas and a reactor that is connected in parallel to the vaporizer and has a heat storage material that generates heat or absorbs heat according to the temperature of ammonia. During operation, heat is extracted from the reactor by the reaction between the high pressure ammonia and the heat storage material. The heat stored in the reactor is used to increase the temperature of the vaporizer and the like.

JP 2013-238356 A

  However, in the above prior art, the ammonia from the ammonia tank reacts with the heat storage material of the reactor to generate heat from the reactor, and the ammonia from the ammonia tank is vaporized by the vaporizer and supplied to the reformer. The At this time, ammonia is heated by transferring the heat generated from the reactor to the vaporizer. However, when the system is started, ammonia that is not warmed by the heat generated from the reactor may be supplied to the reformer. In this case, the start-up of the reforming operation is delayed in the reformer, leading to a decrease in reforming performance of the reformer.

  An object of the present invention is to provide a hydrogen generator capable of improving the reforming performance of a reformer.

  One aspect of the present invention is a modified tank that is connected to a tank for storing ammonia, and the tank through a first passage, and decomposes ammonia supplied from the tank to generate reformed gas mainly containing hydrogen and nitrogen. A hydrogen generating device comprising a mass device, which is connected to a tank through a second passage and generates heat by a chemical reaction with ammonia supplied from the tank and from which ammonia is released when heat is applied. A reaction section having a heat exchange section that is connected to the reaction section through the third passage, heats ammonia by the heat generated from the reaction material, and transfers heat to the reaction material, and a heat exchange section and a reformer. A first on-off valve connected to and connected to the reformer for supplying ammonia heated by the heat exchange unit, and a first on-off valve disposed in the second passage for opening and closing a flow path of ammonia supplied from the tank to the reaction unit And in the first passage And a second on-off valve that opens and closes the flow path of ammonia supplied from the tank to the reformer, and at the time of start-up, the first on-off valve is controlled to be opened and the second on-off valve is closed. And a valve control unit that controls to close the first on-off valve and to open the second on-off valve during normal operation after the start is completed.

  In such a hydrogen generator, at the time of start-up, since the first on-off valve is opened and the second on-off valve is closed, ammonia stored in the tank is supplied to the reaction section through the second passage. Then, heat is generated from the reaction material by a chemical reaction between ammonia and the reaction material in the reaction part, and unreacted ammonia is heated by the heat. And the heated ammonia is supplied to a heat exchange part through a 3rd channel | path. Then, in the heat exchange part, ammonia is further heated by the heat generated from the reaction material. The heated ammonia is supplied to the reformer through the fourth passage. Therefore, at the time of starting, sufficiently heated ammonia is supplied to the reformer. Thereby, since the start of reforming operation is quick in the reformer, the reforming performance of the reformer is improved.

  The reaction section and the reformer are arranged so as to be able to exchange heat via the heat exchange section, and the heat exchange section may transmit the heat of the reformer to the reaction material.

  During normal operation after the start, the first on-off valve is closed and the second on-off valve is opened. At this time, since the reaction section and the reformer are arranged so that heat exchange is possible via the heat exchange section, the heat of the reformer is transmitted to the reaction material through the heat exchange section, and ammonia is transferred from the reaction material. The so-called reaction material that is desorbed is regenerated. In this case, the reaction material can be regenerated with a simple configuration.

  The hydrogen generator is configured to open and close a fifth passage for supplying the reformed gas generated by the reformer to the heat exchange section, and a flow path for the reformed gas provided in the fifth passage and supplied to the heat exchange section A heat exchanger that transmits heat of the reformed gas to the reaction material, and the valve controller controls the first on-off valve to open at the time of start-up and the second on-off valve. And the third on-off valve is controlled to be closed. During normal operation, the first on-off valve and the third on-off valve are controlled to be closed and the second on-off valve is opened to remove ammonia from the reactant. When separating, you may control to close a 1st on-off valve, and to open a 2nd on-off valve and a 3rd on-off valve.

  During normal operation after the start is completed, the first on-off valve and the third on-off valve are closed and the second on-off valve is opened. Then, when regenerating the so-called reaction material from which ammonia is desorbed from the reaction material, the third on-off valve is opened. Then, the reformed gas generated by the reformer is supplied to the heat exchange section through the fifth passage. Then, the heat of the reformed gas is transmitted from the heat exchange part to the reaction material, and ammonia is desorbed from the reaction material. For this reason, the reaction material can be regenerated without bringing the reformer into contact with the heat exchange section. Thereby, a reaction part, a heat exchange part, and a reformer can be arranged with space efficiency.

  The hydrogen generator is disposed in the fifth passage and pumps the reformed gas to the heat exchange part, and controls the pump not to operate during start-up and normal operation to desorb ammonia from the reactant. When making it operate, you may further provide the pump control part which controls so that a pump may be operated.

  In this case, when the pump is operated, the reformed gas is forcibly pumped to the heat exchange section by the pump. As a result, when the reaction material is regenerated, the reformed gas is reliably supplied to the heat exchange section through the fifth passage.

  According to the present invention, the reforming performance of the reformer can be improved.

FIG. 1 is a schematic configuration diagram showing a hydrogen generator according to the first embodiment of the present invention. FIG. 2 is a flowchart showing a procedure of control processing executed by the controller shown in FIG. FIG. 3A is a diagram showing a gas flow at start-up in the hydrogen generator shown in FIG. 1, and FIG. 3B is a regeneration of the reactant in the hydrogen generator shown in FIG. It is a figure which shows the flow of the gas at the time. FIG. 4 is a schematic configuration diagram showing a hydrogen generator according to the second embodiment of the present invention. FIG. 5 is a flowchart showing a procedure of control processing executed by the controller shown in FIG. FIG. 6A is a diagram showing a gas flow at start-up in the hydrogen generator shown in FIG. 4, and FIG. 6B is a regeneration of the reaction material in the hydrogen generator shown in FIG. It is a figure which shows the flow of the gas at the time.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic configuration diagram showing a hydrogen generator according to the first embodiment of the present invention. In FIG. 1, a hydrogen generator 1 of this embodiment is a device that generates hydrogen, and is mounted on, for example, a vehicle. Hydrogen generated by the hydrogen generator 1 is used, for example, in a fuel cell, an engine, a gas turbine, or the like.

The hydrogen generator 1 includes an ammonia tank 2, a compressor 3, a reforming catalyst 4 that is a reformer, and an igniter 5. The ammonia tank 2 stores ammonia (NH ₃ ) as a liquefied gas. The compressor 3 pumps air. The ammonia tank 2 and the reforming catalyst 4 are connected via a pipe 6. The pipe 6 constitutes a first passage. Therefore, the reforming catalyst 4 is connected to the ammonia tank 2 via the first passage. The compressor 3 and the reforming catalyst 4 are connected via a pipe 7.

The reforming catalyst 4 introduces air (or oxygen) from the compressor 3 and decomposes ammonia supplied from the ammonia tank 2, thereby mainly containing hydrogen (H ₂ ) and nitrogen (N ₂ ). Generate reformed gas. The reforming method of the reforming catalyst 4 is, for example, an autothermal reforming (ATR) method. Although not shown in particular, the reforming catalyst 4 oxidizes ammonia by a chemical reaction between ammonia and oxygen in the air to generate heat, and decomposes the ammonia by heat generated in the oxidation part. And a decomposition part that generates hydrogen and nitrogen. That is, a part of ammonia is oxidized in the oxidation part that is the upstream part of the reforming catalyst 4, and the remaining ammonia is hydrogenated in the decomposition part that is the downstream part of the reforming catalyst 4. The compressor 3 supplies an amount of air necessary for the combustion of ammonia. In this embodiment, a ruthenium catalyst or the like is used as the reforming catalyst 4. However, the reforming catalyst 4 is not limited to a ruthenium catalyst, and various precious metal catalysts can be used. Note that the oxidation part that is the upstream part of the reforming catalyst 4 is a part that oxidizes ammonia. Therefore, a catalyst type that is specialized for the oxidation reaction and different from the decomposition part that is the downstream part of the reforming catalyst 4 may be used. . A pipe 8 for supplying the generated reformed gas to the outside is connected to the reforming catalyst 4.

  The igniter 5 includes a reaction unit 10 and a heat exchange unit 11 fixed in contact with the reaction unit 10. The reaction unit 10 is connected to the pipe 6 and the pipe 12. A part of the pipe 6 and the pipe 12 constitute a second passage. Therefore, the reaction unit 10 is connected to the ammonia tank 2 via the second passage.

  The reaction unit 10 includes a container 13 and a reaction material 14 accommodated in the container 13. The container 13 is formed of a metal material (for example, stainless steel) having corrosion resistance against ammonia. The reaction material 14 is a material that generates heat by a chemical reaction with ammonia supplied from the ammonia tank 2 and from which ammonia is released when heat is applied. The reaction material 14 is configured as a particulate or powdery compression molded body.

  As the reaction material 14, a halide represented by the composition formula MaXz is used. M is an alkali metal such as Li or Na, an alkaline earth metal such as Mg, Ca or Sr, a transition metal such as Cr, Mn, Fe, Co, Ni, Cu or Zn, Al, or a combination of these metals. One or more selected cations. X is one or more anions selected from fluoride ion, chloride ion, bromide ion, iodide ion, nitrate ion, thiocyanate ion, sulfate ion, molybdate ion or phosphate ion. X is, for example, Cl, Br, I or the like. a is the number of cations per salt molecule. z is the number of anions per salt molecule.

  The heat exchange unit 11 is disposed between the reaction unit 10 and the reforming catalyst 4. The heat exchange unit 11 is fixed in contact with the reforming catalyst 4. Therefore, the reaction unit 10 and the reforming catalyst 4 are arranged to be able to exchange heat via the heat exchange unit 11. The heat exchange unit 11 is connected to the reaction unit 10 via a pipe 15. The pipe 15 constitutes a third passage. The heat exchange unit 11 has a plurality of heat exchange fins arranged in the housing. The heat exchange part 11 is formed of a metal material (for example, stainless steel) having corrosion resistance against ammonia. The heat exchange unit 11 heats ammonia by the heat generated from the reaction material 14 of the reaction unit 10 and transmits heat of the reforming catalyst 4 to the reaction material 14.

  The heat exchange unit 11 is connected to the pipe 6 and the pipe 16. A part of the pipe 16 and the pipe 6 constitutes a fourth passage that connects the heat exchange unit 11 and the reforming catalyst 4 and supplies ammonia heated by the heat exchange unit 11 to the reforming catalyst 4. The pipes 6, 12, 15, and 16 are also formed of a metal material (for example, stainless steel) having corrosion resistance against ammonia.

  In addition, the hydrogen generator 1 includes an on-off valve 17 disposed on the pipe 12, an on-off valve 18 disposed on the pipe 6, a temperature sensor 19 attached to the pipe 6, and a controller 20. .

  The on-off valve 17 is a first on-off valve that opens and closes a flow path of ammonia supplied from the ammonia tank 2 to the reaction unit 10. The on-off valve 18 is disposed between the connection part S1 and the connection part S2 in the pipe 6. The connection portion S1 is a portion where the pipes 6 and 12 are connected to each other. The connection portion S2 is a portion where the pipes 6 and 16 are connected. The on-off valve 18 is a second on-off valve that opens and closes the flow path of ammonia supplied from the ammonia tank 2 to the reforming catalyst 4.

  The temperature sensor 19 is attached, for example, between the connection portion S2 in the pipe 6 and the reforming catalyst 4, and detects the temperature of ammonia after being heated by the heat exchange unit 11. The temperature sensor 19 may detect the temperature of the reforming catalyst 4 instead of the temperature of ammonia.

  The controller 20 includes a CPU, a RAM, a ROM, an input / output interface, and the like. The controller 20 has a valve control unit 21 that controls the on-off valves 17 and 18. The valve control unit 21 controls to open and close the on-off valve 17 and close the on-off valve 18 during startup, and controls to close the on-off valve 17 and closes the on-off valve 17 during normal operation after the start. 18 is controlled to open.

  FIG. 2 is a flowchart showing a procedure of control processing executed by the controller 20. In the initial state, the on-off valves 17 and 18 are closed. The following procedures are all executed by the valve control unit 21.

  In FIG. 2, the controller 20 first determines whether or not the engine has been started based on the output signal of the ignition switch (step S101). When it is determined that the engine has been started, the controller 20 controls to open the on-off valve 17 (step S102).

  Then, the controller 20 determines whether the temperature of ammonia supplied to the reforming catalyst 4 is equal to or higher than the activation temperature based on the detection value of the temperature sensor 19 (step S103). The activation temperature is a temperature at which the reforming catalyst 4 is activated, and is about 175 ° C., for example. The activation temperature varies depending on the catalyst type of the reforming catalyst 4. When it is determined that the temperature of ammonia supplied to the reforming catalyst 4 is equal to or higher than the activation temperature, the controller 20 controls to close the on-off valve 17 and to open the on-off valve 18 (procedure). S104).

In the hydrogen generator 1 as described above, at the time of starting, the on-off valve 17 is opened and the on-off valve 18 is closed. For this reason, as shown in FIG. 3A, ammonia in the ammonia tank 2 is supplied to the reaction unit 10 through a part of the pipe 6 and the pipe 12, and the inside of the reaction material 14 of the reaction part 10 is ammonia. Pass through. Then, a part of the ammonia chemically reacts (chemical adsorption) with the reaction material 14 to generate heat from the reaction material 14. That is, a reaction from the left side to the right side (exothermic reaction) in the following reaction formula (A) occurs. Thereby, ammonia which has not chemically reacted with the reaction material 14 is heated.
Reactive material + NH ₃ ⇔ Reactive material (NH ₃ ) + Heat (A)

  The ammonia heated in the reaction unit 10 is supplied to the heat exchange unit 11 through the pipe 15 and passes through the inside of the heat exchange unit 11. Then, the heat generated from the reaction material 14 is transferred to the ammonia flowing through the heat exchanging unit 11 and the ammonia is further heated. Then, the ammonia heated in the heat exchange unit 11 is supplied to the reforming catalyst 4 through a part of the pipe 16 and the pipe 6. As a result, the reforming catalyst 4 rises to the activation temperature, so that the reforming catalyst 4 generates reformed gas. In order to reliably raise the reforming catalyst 4 to the activation temperature, the reaction material 14 is preferably a material that generates heat above the activation temperature by reaction with ammonia. In this embodiment, magnesium bromide or the like is used as such a material.

  When the reforming catalyst 4 reaches the activation temperature or higher, the on-off valve 17 is closed and the on-off valve 18 is opened. Thereby, the hydrogen generator 1 is in a normal operation, and the ammonia in the ammonia tank 2 is directly supplied to the reforming catalyst 4 through the pipe 6, and the reforming operation by the reforming catalyst 4 continues.

  When the reforming catalyst 4 is activated, as shown in FIG. 3B, the heat of the high-temperature reforming catalyst 4 is given to the reaction material 14 of the reaction unit 10 through the heat exchange unit 11, thereby causing a reaction. Ammonia is desorbed from the material 14. That is, a reaction (regeneration reaction) from the right side to the left side in the above reaction formula (A) occurs. The desorbed ammonia flows through the pipe 15, the heat exchange unit 11, the pipe 16 and the pipe 6 toward the reforming catalyst 4.

  As described above, in the present embodiment, at the time of start-up, the on-off valve 17 is opened and the on-off valve 18 is closed, so that the ammonia stored in the ammonia tank 2 passes through the pipes 6, 12 to the reaction unit 10. Supplied. Then, heat is generated from the reaction material 14 by a chemical reaction between the ammonia and the reaction material 14 in the reaction unit 10, and unreacted ammonia is heated by the heat. The heated ammonia is supplied to the heat exchange unit 11 through the pipe 15. Then, in the heat exchange unit 11, the ammonia is further heated by the heat generated from the reaction material 14. The heated ammonia is supplied to the reforming catalyst 4 through the pipes 16 and 6. Therefore, at the time of starting, sufficiently heated ammonia is supplied to the reforming catalyst 4. As a result, the reforming catalyst 4 has its reforming operation started quickly, so that the reforming performance of the reforming catalyst 4 is improved.

  In the present embodiment, the opening / closing valve 17 is closed and the opening / closing valve 18 is opened during normal operation after the start is completed. At this time, since the reaction unit 10 and the reforming catalyst 4 are arranged so as to be able to exchange heat via the heat exchange unit 11, the heat of the reforming catalyst 4 is transmitted to the reaction material 14 through the heat exchange unit 11. The so-called reaction material 14 is regenerated in which ammonia is desorbed from the reaction material 14. In this case, regeneration of the reaction material 14 can be realized with a simple configuration.

  Further, in this embodiment, heat is generated from the reaction material 14 by a chemical reaction between ammonia and the reaction material 14 and the ammonia is heated using the heat. Therefore, unlike the case where an electric heater is used, the electric power is supplied at the time of starting. Ammonia heating can be carried out without the need.

  FIG. 4 is a schematic configuration diagram showing a hydrogen generator according to the second embodiment of the present invention. In FIG. 4, the hydrogen generator 30 of the present embodiment is similar to the first embodiment in that the ammonia tank 2, the compressor 3, the reforming catalyst 4 that is a reformer, the reaction unit 10, and the heat exchange. And an igniter 5 having a portion 11. The heat exchange unit 11 is fixed in contact with the reaction unit 10. The reforming catalyst 4 is arranged away from the heat exchange unit 11.

  The hydrogen generator 30 includes a pipe 31 that connects the pipe 8 and the pipe 15, and an on-off valve 32 and a regeneration pump 33 that are disposed in the pipe 31. A part of the pipe 31 and the pipe 15 constitutes a fifth passage for supplying the reformed gas generated by the reforming catalyst 4 to the heat exchange unit 11. For example, the temperature of the reformed gas is about 400 ° C to 500 ° C. The on-off valve 32 is a third on-off valve that opens and closes the flow path of the reformed gas supplied to the heat exchange unit 11. The regeneration pump 33 is disposed on the downstream side (on the heat exchanging unit 11 side) of the on-off valve 32 in the pipe 31. The regeneration pump 33 pumps the reformed gas to the heat exchange unit 11.

  In addition, the hydrogen generator 30 includes a controller 34 instead of the controller 20 in the first embodiment. The controller 34 includes a valve control unit 35 that controls the on-off valves 17, 18, and 32 and a pump control unit 36 that controls the regeneration pump 33.

  The valve control unit 35 controls the open / close valve 17 to be opened and controls the open / close valves 18 and 32 to be closed at the time of starting, and closes the open / close valves 17 and 32 at the time of normal operation after the start is completed. In addition, when controlling the opening / closing valve 18 to open and desorbing ammonia from the reaction material 14 (regeneration of the reaction material 14), the opening / closing valve 17 is controlled and the opening / closing valves 18, 32 are controlled. Control to open. The pump control unit 36 performs control so that the regeneration pump 33 is not operated (turned OFF) during start-up and normal operation, and activates the regeneration pump 33 when desorbing ammonia from the reaction material 14 ( To turn on).

  FIG. 5 is a flowchart showing a procedure of control processing executed by the controller 34. In the initial state, the on-off valves 17, 18, and 32 are in a closed state, and the regeneration pump 33 is in an OFF state.

  In FIG. 5, the controller 34 executes steps S <b> 101 to S <b> 104 similarly to the controller 20 described above. Then, the controller 34 determines whether or not a predetermined time has elapsed since the opening / closing valve 18 was controlled to open (step S105). The predetermined time is a time during which the reaction material 14 can be regenerated, and is determined by experiments or calculations.

  When it is determined that a predetermined time has elapsed since the controller 34 controls to open the on-off valve 18, the controller 34 controls to open the on-off valve 32 (step S106). Then, the controller 34 controls the regeneration pump 33 to operate (step S107).

  Here, steps S <b> 101 to S <b> 106 are executed by the valve control unit 35. Steps S105 and S107 are executed by the pump control unit 36.

  In the hydrogen generator 30 as described above, at the time of starting, the on-off valve 17 is opened and the on-off valve 18 is closed. For this reason, as shown in FIG. 6A, ammonia in the ammonia tank 2 is supplied to the reaction unit 10 through a part of the pipe 6 and the pipe 12. Then, ammonia reacts chemically with the reaction material 14 of the reaction unit 10 to generate heat from the reaction material 14, thereby heating unreacted ammonia passing through the inside of the reaction material 14.

  Then, the ammonia heated in the reaction unit 10 is supplied to the heat exchange unit through the pipe 15. Then, the heat generated from the reaction material 14 is transferred to the ammonia flowing through the heat exchanging unit 11 and the ammonia is further heated. Then, the ammonia heated in the heat exchange unit 11 is supplied to the reforming catalyst 4 through a part of the pipe 16 and the pipe 6. As a result, the reforming catalyst 4 rises to the activation temperature, so that the reforming catalyst 4 generates reformed gas.

  When the reforming catalyst 4 reaches the activation temperature or higher, the on-off valve 17 is closed and the on-off valve 18 is opened. As a result, the hydrogen generator 30 is in a normal operation, and the ammonia in the ammonia tank 2 is directly supplied to the reforming catalyst 4 through the pipe 6, and the reforming operation by the reforming catalyst 4 continues.

  When a predetermined time elapses after the on-off valve 18 is opened, the on-off valve 32 is opened and the regeneration pump 33 is operated as shown in FIG. The reformed gas generated by the above is supplied to the heat exchange unit 11 through a part of the pipe 31 and the pipe 15. Then, since the heat of the high-temperature reformed gas is given to the reaction material 14 of the reaction unit 10, ammonia is desorbed from the reaction material 14. The desorbed ammonia flows through the pipe 15, the heat exchange unit 11, and the pipes 16 and 6 toward the reforming catalyst 4. Further, the reformed gas supplied to the heat exchange unit 11 flows through the pipes 16 and 6 toward the reforming catalyst 4.

  As described above, also in the present embodiment, at the time of starting, sufficiently heated ammonia is supplied to the reforming catalyst 4. As a result, the reforming catalyst 4 has its reforming operation started quickly, so that the reforming performance of the reforming catalyst 4 is improved.

  In the present embodiment, the reformed gas generated by the reforming catalyst 4 is supplied to the heat exchange unit 11 through the pipes 31 and 15. Then, the heat of the reformed gas is transmitted from the heat exchange unit 11 to the reaction material 14, and ammonia is desorbed from the reaction material 14. For this reason, the reaction material 14 can be regenerated without bringing the reforming catalyst 4 into contact with the heat exchange section 11. Thereby, the reaction part 10, the heat exchange part 11, and the reforming catalyst 4 can be arrange | positioned with sufficient space efficiency.

  In the present embodiment, when the regeneration pump 33 is operated, the reformed gas is forcibly pumped to the heat exchange unit 11 by the regeneration pump 33. Thereby, when the reaction material 14 is regenerated, the reformed gas is reliably supplied to the heat exchange unit 11 through the pipes 31 and 15.

  In the present embodiment, the regeneration pump 33 that forcibly pumps the reformed gas to the heat exchange unit 11 is disposed. However, the reformed gas is supplied to the heat exchange unit 11 simply by opening the on-off valve 32. In particular, the regeneration pump 33 may not be used.

  Although several embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, a check valve that prevents the flow of fluid from the heat exchange unit 11 to the reaction unit 10 may be provided in the pipe 15 that connects the reaction unit 10 and the heat exchange unit 11. In this case, ammonia desorbed from the reaction material 14 is prevented from flowing back from the heat exchange unit 11 to the reaction unit 10.

  In the above embodiment, when the temperature of ammonia supplied to the reforming catalyst 4 or the temperature of the reforming catalyst 4 itself is equal to or higher than a predetermined temperature, the on-off valve 17 is closed and the on-off valve 18 is opened. Thus, the normal operation in which the ammonia in the ammonia tank 2 is directly supplied to the reforming catalyst 4 is performed. However, the present invention is not particularly limited to this mode. For example, when a predetermined time has elapsed since the engine was started. The on-off valve 17 may be closed and the on-off valve 18 may be opened.

  Moreover, you may provide the heat exchanger (vaporizer) in order to return the ammonia gas temperature-reduced by the evaporation heat to normal temperature in the exit part of the piping 6 of the ammonia tank 2. FIG. Further, a heat exchanger (cooler) for cooling the reformed gas to an appropriate temperature may be provided in the pipe 8.

  DESCRIPTION OF SYMBOLS 1 ... Hydrogen generator, 2 ... Ammonia tank (tank), 4 ... Reforming catalyst (reformer), 6 ... Pipe (1st passage, 2nd passage, 4th passage), 10 ... Reaction part, 11 ... Heat Exchange part, 12 ... pipe (second passage), 14 ... reactive material, 15 ... pipe (third passage, fifth passage), 16 ... pipe (fourth passage), 17 ... open / close valve (first open / close valve), DESCRIPTION OF SYMBOLS 18 ... On-off valve (2nd on-off valve), 21 ... Valve control part, 30 ... Hydrogen generator, 31 ... Pipe (5th passage), 32 ... On-off valve (3rd on-off valve), 33 ... Regeneration pump (pump ), 35 ... valve control unit, 36 ... pump control unit.

Claims (4)

A tank for storing ammonia; and a reformer connected to the tank via a first passage and decomposing the ammonia supplied from the tank to generate a reformed gas mainly composed of hydrogen and nitrogen. A hydrogen generator comprising:
A reaction section connected to the tank through a second passage, and having a reaction material that generates heat and is released from the ammonia when heated by a chemical reaction with the ammonia supplied from the tank;
A heat exchanging part connected to the reaction part via a third passage, for heating the ammonia by heat generated from the reaction material and transferring heat to the reaction material;
A fourth passage for connecting the heat exchange unit and the reformer, and supplying the ammonia heated by the heat exchange unit to the reformer;
A first on-off valve disposed in the second passage for opening and closing a flow path of the ammonia supplied from the tank to the reaction unit;
A second on-off valve disposed in the first passage for opening and closing a flow path of the ammonia supplied from the tank to the reformer;
At the time of start-up, the first on-off valve is controlled to be opened and the second on-off valve is controlled to be closed. At the normal operation after the start is finished, the first on-off valve is controlled to be closed and the first on-off valve is closed. And a valve control unit that controls the second on-off valve to open. The reaction section and the reformer are arranged so that heat exchange is possible via the heat exchange section,
The hydrogen generation apparatus according to claim 1, wherein the heat exchange unit transfers heat of the reformer to the reaction material. A fifth passage for supplying the reformed gas generated by the reformer to the heat exchange unit;
A third on-off valve disposed in the fifth passage and configured to open and close a flow path of the reformed gas supplied to the heat exchange unit;
The heat exchanging unit transmits heat of the reformed gas to the reaction material,
The valve control unit controls to open the first on-off valve at the time of starting and controls to close the second on-off valve and the third on-off valve, and at the time of the normal operation, the first on-off valve controls the first on-off valve. The on-off valve and the third on-off valve are controlled to be closed and the second on-off valve is controlled to be opened. When the ammonia is desorbed from the reaction material, the first on-off valve is closed. The hydrogen generating apparatus according to claim 1, wherein the second open / close valve and the third open / close valve are controlled to open. A pump disposed in the fifth passage and pumping the reformed gas to the heat exchange unit;
A pump control unit that controls the pump not to operate at the time of starting and the normal operation, and controls the pump to operate when desorbing the ammonia from the reaction material; The hydrogen generator according to claim 3.

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