JP6222515B2 - Fuel reforming system - Google Patents

Description

  The present invention relates to a fuel reforming system. More specifically, the present invention relates to a fuel reforming system that supplies fuel to recirculated exhaust gas and reforms the fuel to generate reformed gas containing hydrogen.

  Conventionally, there has been proposed a control device for an internal combustion engine capable of protecting a fuel reforming catalyst from sulfur content while performing reforming control as much as possible even when the fuel contains a sulfur content. The control apparatus for an internal combustion engine includes a heating unit, and supplies a fuel reforming catalyst that generates a combustible gas from the reformed fuel by heat of the heating unit and a fuel containing at least gasoline to the fuel reforming catalyst as a reformed fuel. A reformed fuel supply means and a sulfur concentration acquisition means for acquiring the sulfur concentration in the reformed fuel are provided. Further, the control device for the internal combustion engine is configured to reduce the reformed fuel supply amount by the reformed fuel supply unit or the temperature of the fuel reforming catalyst as the sulfur concentration in the reformed fuel increases. The temperature acquisition means for acquiring the lower limit temperature setting means for variably setting the lower limit temperature necessary for the fuel reforming catalyst to operate according to the sulfur concentration in the reformed fuel, and the temperature of the fuel reforming catalyst is the lower limit temperature The reformed fuel supply unit further includes a reformed fuel stop unit that stops the supply of the reformed fuel when the temperature is lower (see Patent Document 1).

JP 2009-121296 A

  However, in the fuel reforming system described in Patent Document 1, in order to suppress deterioration of the fuel reforming catalyst, the load range in which fuel reforming can be used is limited, and the fuel consumption improvement is not sufficient. There was a problem.

  The present invention has been made in view of such problems of the prior art. An object of the present invention is to provide a fuel reforming system capable of realizing excellent fuel efficiency improvement while suppressing deterioration of the fuel reforming catalyst.

The inventors of the present invention have made extensive studies in order to achieve the above object. As a result, the air is supplied by the secondary air supply means or the predetermined secondary air supply means to promote the steam reforming reaction in the fuel reforming catalyst, so that the sulfur component adsorbed on the fuel reforming catalyst is desorbed. The present inventors have found that the above object can be achieved by promoting and suppressing or preventing deterioration of the fuel reforming catalyst, and have completed the present invention.

That is, the fuel reforming system of the present invention is a fuel reforming system that reforms a fuel to generate a reformed gas containing hydrogen, and is provided in the reforming supply channel and the reforming supply channel. A fuel reforming catalyst, a fuel supply means that is disposed upstream of the fuel reforming catalyst in the reforming supply channel, and that supplies fuel to the fuel reforming catalyst, and a fuel reforming catalyst in the reforming supply channel A secondary air supply means or a predetermined secondary air supply means, which is arranged on the upstream side and supplies air to the fuel reforming catalyst, and a control means for controlling the fuel supply means and the secondary air supply means. Then, the control means, the fuel supply means and the secondary air supply means for supplying fuel and air to the fuel reforming catalyst is equal Ru is operated, the fuel and air is burned reaction, steam reforming in the fuel reforming catalyst Promote the reaction.

According to the present invention, a reforming supply channel, a fuel reforming catalyst disposed in the reforming supply channel, and a fuel reforming unit disposed upstream of the fuel reforming catalyst in the reforming supply channel. Fuel supply means for supplying fuel to the catalyst, and secondary air supply means for supplying air to the fuel reforming catalyst, which is disposed upstream of the fuel reforming catalyst in the reforming supply flow path, or predetermined secondary air supply means and, and a control means for controlling fuel supply means and the secondary air supply means, control means, the fuel reforming catalyst in the fuel and air equal to Ru actuates the fuel supply means and the secondary air supply means for supplying Thus , the fuel and air are subjected to a combustion reaction to promote the steam reforming reaction in the fuel reforming catalyst. Therefore, it is possible to provide a fuel reforming system that can realize excellent fuel efficiency improvement while suppressing deterioration of the fuel reforming catalyst.

FIG. 1 is an explanatory diagram showing an outline of a fuel reforming system according to a first embodiment. FIG. 2 is a flowchart showing an example of a control flow in the fuel reforming system according to the first embodiment. FIG. 3 is a flowchart showing another example of the control flow in the fuel reforming system according to the first embodiment. FIG. 4 is a flowchart showing still another example of the control flow in the fuel reforming system according to the first embodiment. FIG. 5 is an explanatory diagram showing an outline of the fuel reforming system according to the second embodiment. FIG. 6 is a flowchart showing an example of a control flow in the fuel reforming system according to the second embodiment. FIG. 7 is an explanatory diagram showing an outline of the fuel reforming system according to the third embodiment. FIG. 8 is a flowchart showing an example of a control flow in the fuel reforming system according to the third embodiment. FIG. 9 is a graph showing the performance change rate in the fuel reforming system according to the first or third embodiment.

  Hereinafter, a fuel reforming system according to an embodiment of the present invention will be described in detail. Further, the fuel reforming system of the present invention includes, for example, hydrogen in the exhaust gas circulation passage of the internal combustion engine by reacting the fuel of the internal combustion engine and at least a part of the exhaust of the internal combustion engine to reform the fuel. A fuel reforming system that generates reformed gas is preferred. Therefore, in the fuel reforming system according to one aspect of the present invention, in the exhaust gas circulation passage of the internal combustion engine, the fuel of the internal combustion engine and at least a part of the exhaust of the internal combustion engine are reacted to reform the fuel. A fuel reforming system that generates reformed gas containing hydrogen will be described as an example.

(First form)
First, the fuel reforming system according to the first embodiment will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing an outline of a fuel reforming system according to a first embodiment.

  As shown in FIG. 1, a fuel reforming system 1A of the present embodiment includes a four-cycle engine 10 that is an example of an internal combustion engine, an intake passage (hereinafter referred to as “intake pipe”) 20, an exhaust passage (hereinafter referred to as “exhaust”). 30 ”, an exhaust gas circulation passage (hereinafter referred to as an“ EGR (Exhaust Gas Recirculation) pipe ”) 40 that is an example of a reforming supply passage, and a controller 50 that is an example of a control means. ing. The engine 10 and the intake pipe 20 are connected by an intake port 12 a of the combustion chamber 12 of the cylinder 11. Further, the engine 10 and the exhaust pipe 30 are connected by an exhaust port 12 b of the combustion chamber 12. Further, the EGR pipe 40 connects the exhaust pipe 30 and the intake pipe 20.

  Further, the engine 10 includes an intake valve 13 that opens and closes the intake port 12a, an exhaust valve 14 that opens and closes the exhaust port 12b, a piston 15 that reciprocates in the cylinder 11, and an air-fuel mixture in the combustion chamber 12. A spark plug 16 is provided for skipping electric sparks.

  Further, the intake pipe 20 is provided with a main fuel supply device 21 in the vicinity of the intake port 12a, and the air flowing in the intake pipe 20 toward the combustion chamber 12 on the upstream side of the main fuel supply device 21 in the intake direction. An intake control valve 22 for controlling the amount of air is further provided. Here, the main fuel supply device 21 has a function of injecting main fuel into the combustion chamber 12 or the intake pipe 20.

  The exhaust pipe 30 is provided with an exhaust control valve 31 for controlling the exhaust amount of the exhaust gas flowing through the exhaust pipe 30.

  Further, in the EGR pipe 40, a secondary air injection device 41a which is an example of a secondary air supply means in a direction from the upstream side to the downstream side in the exhaust gas flow direction (indicated by an arrow α in the figure), A reforming fuel injection device 42, which is an example of a fuel supply means, a fuel reforming catalyst 43, a temperature detector 44, an EGR cooler 45, and an EGR valve 46 are sequentially arranged. The EGR pipe 40 is for diverting a part of the exhaust from the exhaust pipe 30 to the intake pipe 20, that is, for refluxing. For example, in the fuel reforming system 1A, a part of the exhaust gas that has been stoichiometrically combusted in the combustion chamber 12 is diverted from the exhaust pipe 30 to the EGR pipe 40, and the reforming fuel is injected into the exhaust gas by the reforming fuel injection device 42. In addition, the fuel for reforming can be reformed into reformed gas containing hydrogen by the fuel reforming catalyst 43 and can be returned to the intake pipe 20.

  Here, the secondary air injection device 41a is for accelerating the steam reforming reaction in the fuel reforming catalyst 43 to obtain a reformed gas containing hydrogen, and only the air contained in the exhaust gas. Then, when it is insufficient, it has a function of injecting air into the exhaust gas flowing toward the fuel reforming catalyst 43 through the fuel reforming catalyst 43 or the EGR pipe 40.

  The reforming fuel injection device 42 has a function of injecting reforming fuel into the exhaust gas flowing toward the fuel reforming catalyst 43 through the fuel reforming catalyst 43 or the EGR pipe 40. The reforming fuel may be the same as or different from the main fuel.

  Further, the fuel reforming catalyst 43 has a function of causing the reforming fuel and at least a part of the exhaust to react and reforming the fuel to generate a reformed gas containing hydrogen. Normally, since exhaust gas contains heat and moisture, the fuel reforming catalyst promotes the steam reforming reaction to generate reformed gas containing hydrogen by adding reforming fuel. In particular, when air is further added by the secondary air injection means, a fuel reaction between fuel and air occurs, and the steam reforming reaction is further promoted.

  The temperature detector 44 has a function of measuring the outlet side temperature of the fuel reforming catalyst. A conventionally known temperature detector such as a thermocouple thermometer can be applied.

  Furthermore, the EGR cooler 45 has a function of cooling exhaust gas and reformed gas.

  The EGR valve 46 has a function of controlling the flow rate of exhaust gas and reformed gas.

  Further, the controller 50 including a central processing unit (CPU) and an interface circuit includes a main fuel supply device 21, an intake control valve 22, an exhaust control valve 31, a secondary air injection device 41a, a reforming fuel injection device 42, The temperature detector 44 and the EGR valve 46 are connected to input / output signals relating to control, and these are appropriately operated by executing a predetermined program. The controller 50 is connected to a control unit (not shown) such as the intake valve 13, the exhaust valve 14, and the piston 15, and inputs / outputs signals related to control, and operates them appropriately by executing a predetermined program. You may come to let me.

  In the fuel reforming system 1A of the present embodiment, the controller 50 operates the reforming fuel injection device 42 and the secondary air injection device 41a that supply fuel and air to the fuel reforming catalyst 43. As a result, the fuel and air undergo a combustion reaction and the temperature rises, so that the steam reforming reaction in the fuel reforming catalyst 43 is promoted and the reformed gas concentration in the atmosphere increases. As a result, the desorption of the sulfur component adsorbed on the fuel reforming catalyst 43 can be promoted. In addition, since it is possible to regenerate the fuel reforming catalyst without requiring a means for detecting the performance degradation or performance degradation of the fuel reforming catalyst, it is possible to simplify the in-vehicle system. There are also advantages.

  Further, in the fuel reforming system 1A of the present embodiment, for example, the controller 50 has an outlet side of the fuel reforming catalyst 43 in which the steam reforming reaction in the fuel reforming catalyst 43 acquired in advance by a preliminary experiment or the like is promoted. The outlet side temperature of the fuel reforming catalyst 43 input from the temperature detector 44 is compared with the temperature and the outlet side temperature of the fuel reforming catalyst 43 actually input from the temperature detector 44. When it is determined that the outlet side temperature of the fuel reforming catalyst 43 at which the steam reforming reaction in 43 is promoted, the secondary air injection device 41a that supplies air to the fuel reforming catalyst 43 may be operated. Is preferred. This is because when the temperature on the outlet side of the fuel reforming catalyst is a temperature at which hydrogen generation is not possible by the steam reforming reaction, even if the secondary air is supplied, the reforming containing hydrogen necessary for promoting the desorption of sulfur components is performed. This is because no gas can be obtained and the sulfur component desorption promotion effect may not be sufficiently obtained. On the other hand, when the outlet side temperature of the fuel reforming catalyst reaches a temperature at which hydrogen can be generated by the steam reforming reaction, if secondary air is supplied, hydrogen necessary for promoting the desorption of sulfur components is included. A reformed gas is obtained, and a sulfur component desorption promotion effect is sufficiently obtained.

  Furthermore, in the fuel reforming system 1A of the present embodiment, for example, when the controller 50 stops the operation of the reforming fuel injection device 42 so as not to supply fuel to the fuel reforming catalyst 43, the fuel reforming catalyst. It is preferable to operate the secondary air injection device 41 a that supplies air to the air 43. That is, when the operation of the reforming fuel injection device is stopped, the fuel reforming is performed immediately before, so that the outlet temperature of the fuel reforming catalyst reaches the temperature at which the steam reforming reaction proceeds. When secondary air is supplied in this state, the sulfur component adsorbed on the fuel reforming catalyst during fuel reforming can be desorbed in a timely manner. Further, when the fuel reforming is stopped, the sulfur component adsorbed on the fuel reforming catalyst is desorbed, so that the next fuel reforming can be started quickly when the fuel reforming is started.

  Further, in the fuel reforming system 1A of the present embodiment, for example, when the controller 50 starts the operation of the reforming fuel injection device 42 so as to supply fuel to the fuel reforming catalyst 43, the fuel reforming catalyst. It is preferable to operate the secondary air injection device 41 a that supplies air to the air 43. Usually, in the fuel reforming system of this embodiment, when the operation of the reforming fuel injection device is started, the outlet side temperature of the fuel reforming catalyst reaches the temperature at which the steam reforming reaction proceeds. When secondary air is supplied in this state, the sulfur component adsorbed on the fuel reforming catalyst during fuel reforming can be desorbed in a timely manner. Even when the reforming reaction is not performed until immediately before, the exhaust gas may be circulated in the EGR pipe, and at that time, the sulfur component may be adsorbed on the fuel reforming catalyst. Further, by desorbing the sulfur component adsorbed on the fuel reforming catalyst when starting the fuel reforming, the fuel reforming catalyst can be quickly reformed, and deterioration of the fuel reforming catalyst can be suppressed. .

Further, in the fuel reforming system 1A of the present embodiment, for example, the controller 50 supplies air to the fuel reforming catalyst so as to obtain a stoichiometric to rich atmosphere in which the steam reforming reaction in the fuel reforming catalyst is promoted. It is preferable to operate the secondary air injection device 41a. This is because it may be difficult to obtain a reformed gas containing desired hydrogen in a lean atmosphere. Specifically, the stoichiometric to rich atmosphere includes the number of moles of oxygen (O ₂ ) in the air supplied by the secondary air injector and the reforming fuel supplied by the reforming fuel injector. The ratio of the number of moles of carbon (C) (O ₂ / C) is preferably 0.3 to 1.5.

  In the fuel reforming system 1A of the present embodiment, for example, the controller 50 has a space velocity at which the combustion reaction between the fuel and air in the fuel reforming catalyst and the steam reforming reaction in the fuel reforming catalyst are promoted. It is preferable to operate the secondary air injection device 41a that supplies air to the fuel reforming catalyst. This is because if the space velocity is too high, that is, if the supply amount of air is too large, it may be difficult to obtain a reformed gas containing the desired hydrogen.

  Although not particularly limited, desorption of the sulfur component adsorbed on the fuel reforming catalyst can be further promoted by setting the above-described temperature, atmosphere, and space velocity.

  Here, a control flow in the fuel reforming system of the present embodiment will be described with reference to the drawings. FIG. 2 is a flowchart showing an example of a control flow in the fuel reforming system of the present embodiment (see FIG. 1).

  For example, the control flow is started when fuel reforming is being performed.

  As shown in FIG. 2, in step 1 (indicated as “S1” in the figure. The same applies to the following description), the outlet temperature of the fuel reforming catalyst 43 is equal to or higher than X ° C. Determine whether or not. If it is determined in S1 that the outlet temperature of the fuel reforming catalyst 43 is equal to or higher than X ° C, the process proceeds to S2. On the other hand, if it is determined in S1 that the outlet temperature of the fuel reforming catalyst 43 is not equal to or higher than X ° C., the process returns to S1. In the present invention, “X ° C.” means the outlet side temperature at which the steam reforming reaction in the fuel reforming catalyst is promoted.

  In S2, the operation of the secondary air injection device 41a is started, and the process proceeds to S3.

  In S3, the supply amount of reforming fuel in the reforming fuel injection device 42 is adjusted, and the process proceeds to S4.

In S4, the number of moles of oxygen (O ₂ ) in the air supplied by the secondary air injection device 41a and the number of moles of carbon (C) in the reforming fuel supplied by the reforming fuel injection device 42. It is determined whether or not the ratio (O ₂ / C) is Y or more and Z or less. When (O ₂ / C) is not less than Y and not more than Z in S4, the process proceeds to S5. On the other hand, if (O ₂ / C) is not Y or more and Z or less in S4, the process returns to S3. In the present invention, “O ₂ / C is Y or more and Z or less” means an atmosphere in which the steam reforming reaction in the fuel reforming catalyst is promoted.

  In S5, the sulfur gas adsorbed on the fuel reforming catalyst 43 is desorbed by the generated reformed gas, and the process proceeds to S6.

  In S6, the supply amount of reforming fuel in the reforming fuel injection device 42 is adjusted to a predetermined supply amount, and the process proceeds to S7. In the present invention, the “predetermined supply amount” usually means the supply amount of the reforming fuel supplied when the reforming gas containing hydrogen is generated in the fuel reforming catalyst.

  In S7, the operation of the secondary air injection device 41a is stopped and the control flow is ended.

  FIG. 3 is a flowchart showing another example of the control flow in the fuel reforming system of the present embodiment (see FIG. 1).

  For example, the control flow is started when the fuel reform is to be finished.

  In S11, it is determined whether or not the operation of the reforming fuel injection device 42 is stopped. When it is determined in S11 that the operation of the reforming fuel injection device 42 is stopped, the process proceeds to S12. On the other hand, if it is determined in S11 that the operation of the reforming fuel injection device 42 is not stopped, the process returns to S11.

  In S12, it is determined whether or not the outlet temperature of the fuel reforming catalyst 43 is equal to or higher than X ° C. If it is determined in S12 that the outlet temperature of the fuel reforming catalyst is equal to or higher than X ° C., the process proceeds to S13. On the other hand, if it is determined in S12 that the outlet temperature of the fuel reforming catalyst is not equal to or higher than X ° C., the process returns to S12.

  In S13, the operation of the secondary air injection device 41a is started, and the process proceeds to S14.

  In S14, the supply amount of reforming fuel in the reforming fuel injection device 42 is adjusted, and the process proceeds to S15.

In S15, the number of moles of oxygen (O ₂ ) in the air supplied by the secondary air injector 41a and the number of moles of carbon (C) in the reforming fuel supplied by the reforming fuel injector 42. It is determined whether or not the ratio (O ₂ / C) is Y or more and Z or less. When (O ₂ / C) is not less than Y and not more than Z in S15, the process proceeds to S16. On the other hand, when (O ₂ / C) is not Y or more and Z or less in S15, the process returns to S14.

  In S16, the sulfur component adsorbed on the fuel reforming catalyst 43 is desorbed by the generated reformed gas, and the process proceeds to S17.

  In S17, the operation of the reforming fuel injection device 42 is stopped, and the process proceeds to S18.

  In S18, the operation of the secondary air injection device 41a is stopped and the control flow is ended.

  FIG. 4 is a flowchart showing another example of the control flow in the fuel reforming system of the present embodiment (see FIG. 1).

  For example, when starting fuel reforming, the control flow is started.

  In S21, it is determined whether or not to start the operation of the reforming fuel injection device 42. If it is determined in S21 that the operation of the reforming fuel injection device 42 is started, the process proceeds to S22. On the other hand, if it is determined in S21 that the operation of the reforming fuel injection device 42 is not started, the process returns to S21.

  In S22, it is determined whether or not the outlet side temperature of the fuel reforming catalyst 43 is equal to or higher than X ° C. When it is determined in S22 that the outlet temperature of the fuel reforming catalyst is equal to or higher than X ° C., the process proceeds to S23. On the other hand, if it is determined in S22 that the outlet temperature of the fuel reforming catalyst is not equal to or higher than X ° C., the process returns to S22.

  In S23, the operation of the secondary air injection device 41a is started, and the process proceeds to S24.

  In S24, the supply amount of reforming fuel in the reforming fuel injection device 42 is adjusted, and the process proceeds to S25.

In S25, the number of moles of oxygen (O ₂ ) in the air supplied by the secondary air injection device 41a and the number of moles of carbon (C) in the reforming fuel supplied by the reforming fuel injection device 42. It is determined whether or not the ratio (O ₂ / C) is Y or more and Z or less. If (O ₂ / C) is not less than Y and not more than Z in S25, the process proceeds to S26. On the other hand, when (O ₂ / C) is not Y or more and Z or less in S25, the process returns to S24.

  In S26, the sulfur gas adsorbed on the fuel reforming catalyst 43 is desorbed by the generated reformed gas, and the process proceeds to S27.

  In S27, the supply amount of reforming fuel in the reforming fuel injection device 42 is adjusted to a predetermined supply amount, and the process proceeds to S28.

  In S28, the operation of the secondary air injection device 41a is stopped, and the control flow is ended.

(Second form)
Next, the fuel reforming system according to the second embodiment will be described in detail with reference to the drawings. FIG. 5 is an explanatory diagram showing an outline of the fuel reforming system according to the second embodiment. In addition, about the structure same as the said form, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  As shown in FIG. 5, the fuel reforming system 1B of the present embodiment supplies secondary air to the EGR pipe 40 in the direction from the upstream side to the downstream side in the exhaust gas flow direction (indicated by an arrow α in the figure). A reed valve 41b which is an example of a means, a reforming fuel injection device 42 which is an example of a fuel supply means, a fuel reforming catalyst 43, a temperature detector 44, an EGR cooler 45, and an EGR valve 46 are sequentially provided. The arrangement is different from the fuel reforming system according to the above embodiment.

  Further, in the fuel reforming system 1B of the present embodiment, the configuration in which the reed valve 41b disposed instead of the secondary air injection device is not connected to the controller 50 is the same as the fuel reforming system according to the above embodiment. It is different.

  In the fuel reforming system 1B of the present embodiment, the controller 50 includes the main fuel supply device 21, the intake control valve 22, the exhaust control valve 31, the reforming fuel injection device 42, the temperature detector 44, the EGR cooler 45, It is connected to the EGR valve 46, inputs / outputs signals related to control, and operates them appropriately by executing a predetermined program. The controller 50 is connected to a control unit (not shown) such as the intake valve 13, the exhaust valve 14, and the piston 15, and inputs / outputs signals related to control, and operates them appropriately by executing a predetermined program. You may come to let me.

Here, the reed valve 41b can flow gas only in one direction according to the pressure difference, and has a function of taking in external air when the pressure in the EGR pipe drops below a predetermined value. If it is, it can apply, without being specifically limited. In such a reed valve, since the amount of air taken in depends on the diameter and pressure of the reed valve, adjusting the amount of reforming fuel supplied by the reforming fuel injection device according to the pressure causes There is an advantage that the value of (O ₂ / C) can be easily adjusted within a preferable range. Therefore, by knowing in advance the amount of air taken in by the reed valve by a preliminary experiment or the like, it is only necessary to supply the reforming fuel corresponding to it. In addition, such a reed valve has an advantage that no special control is required. Further, the predetermined value can be set as appropriate in a preliminary experiment using the applied engine. Furthermore, in the present invention, it may be interlocked with control in which the pressure drops below a predetermined value.

  In the fuel reforming system 1B of the present embodiment, the pressure in the EGR pipe 40 is lowered by the pressure reducing means that reduces the pressure in the EGR pipe 40. As a result, external air is taken into the EGR pipe 40 by the reed valve 41b, and the fuel and air undergo a combustion reaction and the temperature rises, so that the steam reforming reaction in the fuel reforming catalyst 43 is promoted and the atmosphere is improved. The quality gas concentration becomes high. As a result, the desorption of the sulfur component adsorbed on the fuel reforming catalyst 43 can be promoted. In addition, since it is possible to regenerate the fuel reforming catalyst without requiring a means for detecting the performance degradation or performance degradation of the fuel reforming catalyst, it is possible to simplify the in-vehicle system. There are also advantages.

  The pressure reducing means is not particularly limited because it is sufficient to apply various negative pressures generated in the fuel reforming system 1B.

  For example, by cooperating the EGR cooler 45 and the controller 50, it can function as the pressure reducing means described above. Specifically, by cooling the exhaust gas and the reformed gas in the downstream area of the EGR pipe by the EGR cooler 45, the pressure in the downstream area can be reduced, and the pressure in the EGR pipe is lowered. As a result, external air is taken into the EGR pipe 40 by the reed valve 41b.

  Further, for example, by causing the main fuel supply device 21, the reforming fuel injection device 42, the control unit such as the intake valve 13, the exhaust valve 14, the piston 15, and the controller 50 to cooperate with each other, the pressure reduction described above is performed. It can function as a means. Specifically, the cylinder 11 in which all or part of the main fuel supply device 21 of the engine 10 is stopped when the reforming fuel injection device 42 is operating may be used. That is, the pressure in the upstream region of the EGR pipe is set by opening the exhaust valve 14 of the cylinder 11 and closing the intake valve 13 and moving the piston 15 in the direction from the top dead center to the bottom dead center. And the pressure in the EGR pipe is lowered. As a result, external air is taken into the EGR pipe 40 by the reed valve 41b. Needless to say, the piston 15 may be continuously reciprocated.

  Here, a control flow in the fuel reforming system of the present embodiment will be described with reference to the drawings. FIG. 6 is a flowchart showing an example of a control flow in the fuel reforming system of the present embodiment (see FIG. 5).

  For example, the control flow is started when fuel reforming is being performed.

  As shown in FIG. 6, in S31, it is determined whether or not the reforming fuel injection device 42 is operating. If it is determined in S31 that the reforming fuel injection device 42 is operating, the process proceeds to S32. On the other hand, if it is determined in S31 that the reforming fuel injection device 42 is not operating, the process returns to S31.

  In S32, it is determined whether or not the pressure in the EGR pipe 40, which is an example of the reforming supply flow path, has decreased. If it is determined that the pressure in the EGR pipe 40 has decreased, the process proceeds to S33. On the other hand, if it is determined in S32 that the pressure in the EGR pipe 40 has not decreased, the process returns to S32.

  In S33, the operation of the reed valve 41b is started, external air is taken in, and the process proceeds to S34.

  In S34, the generated reformed gas causes the sulfur component adsorbed on the fuel reforming catalyst 43 to be desorbed, and the control flow ends.

(Third form)
Next, a fuel reforming system according to a third embodiment will be described in detail with reference to the drawings. FIG. 7 is an explanatory diagram showing an outline of the fuel reforming system according to the third embodiment. In addition, about the structure same as the said form, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  As shown in FIG. 7, the fuel reforming system 1C of the present embodiment supplies secondary air to the EGR pipe 40 in a direction from the upstream side to the downstream side in the exhaust gas flow direction (indicated by an arrow α in the figure). Secondary air injection device 41a which is an example of the means, reforming fuel injection device 42 which is an example of the fuel supply means, fuel reforming catalyst 43, temperature detector 44, EGR cooler 45, and deterioration degree detection The configuration in which the hydrogen concentration detector 47, which is an example of the means, and the EGR valve 46 are sequentially arranged is different from the fuel reforming system according to the above embodiment.

  Further, in the fuel reforming system 1C of the present embodiment, the controller 50 includes the main fuel supply device 21, the intake control valve 22, the exhaust control valve 31, the secondary air injection device 41a, the reforming fuel injection device 42, the temperature detection. The fuel according to the above-described embodiment is configured to be connected to the detector 44, the EGR valve 46, and the hydrogen concentration detector 47, to input / output signals related to control, and to operate them appropriately by executing a predetermined program. It is different from the reforming system. The controller 50 is connected to a control unit (not shown) such as the intake valve 13, the exhaust valve 14, and the piston 15, and inputs / outputs signals related to control, and operates them appropriately by executing a predetermined program. You may come to let me.

  Here, the hydrogen concentration detector 47 is not particularly limited as long as it has a function of detecting the hydrogen concentration in the downstream region of the fuel reforming catalyst in the EGR pipe.

  In the fuel reforming system 1C of the present embodiment, the controller 50 operates the reforming fuel injection device 42 and the secondary air injection device 41a for supplying fuel and air to the fuel reforming catalyst 43, and in advance. Secondary air supply amount-degradation recovery degree map data indicating the relationship between the acquired secondary air supply amount of the secondary air supply means and the deterioration recovery degree of the fuel reforming catalyst, and the input from the deterioration degree detection means Then, the secondary air supply means for supplying air to the fuel reforming catalyst is operated so as to supply a secondary air supply amount of air for recovering the degree of deterioration of the fuel reforming catalyst. As a result, the fuel and air undergo a combustion reaction and the temperature rises, so that the steam reforming reaction in the fuel reforming catalyst 43 is promoted and the reformed gas concentration in the atmosphere increases. As a result, desorption of the sulfur component adsorbed on the fuel reforming catalyst 43 can be further promoted. Note that this operation can be repeated when the controller 50 determines that the deterioration recovery is not sufficient by the input from the hydrogen concentration detector 47. As a result, the sulfur component adsorbed on the fuel reforming catalyst 43 can be sufficiently desorbed.

  Here, a control flow in the fuel reforming system of the present embodiment will be described with reference to the drawings. FIG. 8 is a flowchart showing an example of a control flow in the fuel reforming system of the present embodiment (see FIG. 7).

  For example, the control flow is started when fuel reforming is being performed.

  As shown in FIG. 8, in S41, it is determined whether or not the outlet side temperature of the fuel reforming catalyst 43 is equal to or higher than X ° C. If it is determined in S41 that the outlet temperature of the fuel reforming catalyst 43 is equal to or higher than X ° C., the process proceeds to S42. On the other hand, if it is determined in S41 that the outlet side temperature of the fuel reforming catalyst 43 is not equal to or higher than X ° C., the process returns to S41.

  In S42, the operation of the secondary air injection device 41a is started, and the process proceeds to S43.

  In S43, the supply amount of reforming fuel in the reforming fuel injection device 42 is adjusted, and the process proceeds to S44.

In S44, the number of moles of oxygen (O ₂ ) in the air supplied by the secondary air injector 41a and the number of moles of carbon (C) in the reforming fuel supplied by the reforming fuel injector 42. It is determined whether or not the ratio (O ₂ / C) is Y or more and Z or less. When (O ₂ / C) is not less than Y and not more than Z in S44, the process proceeds to S45. On the other hand, if (O ₂ / C) is not Y or more and Z or less in S44, the process returns to S43.

  In S45, the sulfur gas adsorbed on the fuel reforming catalyst 43 is desorbed by the generated reformed gas, and the process proceeds to S46.

  In S46, it is determined whether or not the deterioration of the fuel reforming catalyst 43 has been recovered according to the input from the hydrogen concentration detector 47. If it is determined in S46 that the deterioration of the fuel reforming catalyst 43 has been recovered, the process proceeds to S47. On the other hand, if it is determined that the deterioration of the fuel reforming catalyst 43 has not recovered, the process returns to S43.

  In S47, the supply amount of reforming fuel in the reforming fuel injection device 42 is adjusted to a predetermined supply amount, and the process proceeds to S48.

  In S48, the operation of the secondary air injection device 41a is stopped and the control flow is ended.

  FIG. 9 is a graph showing the performance change rate in the fuel reforming system according to the first or third embodiment. As shown in FIG. 9, when there is no supply of secondary air (indicated by the solid line in the figure), the reformed fuel and the sulfur component in the exhaust are affected by adsorption to the fuel reforming catalyst. The hydrogen generation ability of the fuel reforming catalyst is significantly reduced. Further, as shown in FIG. 9, for example, when the secondary air is supplied in the fuel reforming system according to the first embodiment (shown by a one-dot chain line in the figure), it is adsorbed on the fuel reforming catalyst. Desorption of the sulfur component is promoted, and a certain degree of performance change is exhibited. Further, as shown in FIG. 9, when the secondary air is supplied in the fuel reforming system according to the third embodiment (indicated by a two-dot chain line in the figure), the secondary air is selected according to the degree of deterioration. Therefore, the desorption of sulfur components adsorbed on the fuel reforming catalyst is promoted by adjusting the temperature, atmosphere and space velocity according to the degree of deterioration, and by repeating regeneration control. Indicates.

  According to the present invention, in a fuel reforming system for reforming fuel to generate a reformed gas containing hydrogen, a reforming supply passage, a fuel reforming catalyst disposed in the reforming supply passage, A fuel supply means for supplying fuel to the fuel reforming catalyst and upstream of the fuel reforming catalyst in the reforming supply channel; A secondary air supply means for supplying air to the reforming catalyst, and a fuel supply means for controlling the fuel supply means and the secondary air supply means, wherein the control means supplies fuel and air to the fuel reforming catalyst. The means and the secondary air supply means are operated to cause the fuel and air to undergo a combustion reaction to promote the steam reforming reaction in the fuel reforming catalyst. Therefore, it is possible to provide a fuel reforming system that can realize excellent fuel efficiency improvement while suppressing deterioration of the fuel reforming catalyst.

  Further, according to the present invention, in a fuel reforming system for reacting a fuel of an internal combustion engine and at least a part of an exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen, the exhaust of the internal combustion engine A gas circulation channel, a fuel reforming catalyst disposed in the exhaust gas circulation channel, and a fuel that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation channel and supplies fuel to the fuel reforming catalyst A supply means, a secondary air supply means that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation passage and supplies air to the fuel reforming catalyst, and controls the fuel supply means and the secondary air supply means Control means, and the control means operates a fuel supply means and a secondary air supply means for supplying fuel and air to the fuel reforming catalyst to cause a combustion reaction of the fuel and air, and steam reforming in the fuel reforming catalyst In a structure that promotes the reaction Rukoto is preferred. Thus, it is possible to provide a fuel reforming system for an internal combustion engine that can realize excellent fuel efficiency improvement while suppressing deterioration of the fuel reforming catalyst.

  Furthermore, in the present invention, in a fuel reforming system that reacts a fuel of an internal combustion engine and at least a part of the exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen, the exhaust of the internal combustion engine A gas circulation channel, a fuel reforming catalyst disposed in the exhaust gas circulation channel, and a fuel that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation channel and supplies fuel to the fuel reforming catalyst A supply means, a secondary air supply means that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation passage and supplies air to the fuel reforming catalyst, and controls the fuel supply means and the secondary air supply means A control means and a temperature detector for measuring the outlet side temperature of the fuel reforming catalyst, the control means actuates a fuel supply means and a secondary air supply means for supplying fuel and air to the fuel reforming catalyst, Combustion reaction of fuel and air, fuel Further, the steam reforming reaction in the catalyst is promoted, and the fuel reforming catalyst outlet temperature at which the steam reforming reaction in the fuel reforming catalyst acquired in advance is further promoted and input from the temperature detector. The outlet side temperature of the fuel reforming catalyst input from the temperature detector is compared with the outlet side temperature of the fuel reforming catalyst, and the fuel reforming catalyst in which the steam reforming reaction in the fuel reforming catalyst is promoted. It is preferable that the secondary air supply means for supplying air to the fuel reforming catalyst is operated when it is determined that the outlet side temperature has been reached. Thus, it is possible to provide a fuel reforming system for an internal combustion engine that can achieve excellent fuel efficiency improvement while efficiently suppressing deterioration of the fuel reforming catalyst.

  Further, according to the present invention, in a fuel reforming system for reacting a fuel of an internal combustion engine and at least a part of an exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen, the exhaust of the internal combustion engine A gas circulation channel, a fuel reforming catalyst disposed in the exhaust gas circulation channel, and a fuel that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation channel and supplies fuel to the fuel reforming catalyst A supply means, a secondary air supply means that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation passage and supplies air to the fuel reforming catalyst, and controls the fuel supply means and the secondary air supply means Control means, and the control means operates a fuel supply means and a secondary air supply means for supplying fuel and air to the fuel reforming catalyst to cause a combustion reaction of the fuel and air, and steam reforming in the fuel reforming catalyst In a structure that promotes the reaction Further, it is preferable that the secondary air supply means for supplying air to the fuel reforming catalyst is operated when the operation of the fuel supply means is stopped so as not to supply the fuel to the fuel reforming catalyst. It is. As a result, the performance of the catalyst can be recovered when fuel reforming is not being performed, so that the fuel reforming system for an internal combustion engine that can realize excellent fuel efficiency improvement while suppressing deterioration of the fuel reforming catalyst in a timely manner. Can be provided.

  Furthermore, in the present invention, in a fuel reforming system that reacts a fuel of an internal combustion engine and at least a part of the exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen, the exhaust of the internal combustion engine A gas circulation channel, a fuel reforming catalyst disposed in the exhaust gas circulation channel, and a fuel that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation channel and supplies fuel to the fuel reforming catalyst A supply means, a secondary air supply means that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation passage and supplies air to the fuel reforming catalyst, and controls the fuel supply means and the secondary air supply means Control means, and the control means operates a fuel supply means and a secondary air supply means for supplying fuel and air to the fuel reforming catalyst to cause a combustion reaction of the fuel and air, and steam reforming in the fuel reforming catalyst In a structure that promotes the reaction Further, it is preferable that the secondary air supply means for supplying air to the fuel reforming catalyst is operated when the operation of the fuel supply means is started so as to supply fuel to the fuel reforming catalyst. It is. As a result, the performance of the catalyst can be recovered when fuel reforming is not being performed, so that the fuel reforming system for an internal combustion engine that can realize excellent fuel efficiency improvement while suppressing deterioration of the fuel reforming catalyst in a timely manner. Can be provided.

  Further, according to the present invention, in a fuel reforming system for reacting a fuel of an internal combustion engine and at least a part of an exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen, the exhaust of the internal combustion engine A gas circulation channel, a fuel reforming catalyst disposed in the exhaust gas circulation channel, and a fuel that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation channel and supplies fuel to the fuel reforming catalyst A supply means, a secondary air supply means that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation passage and supplies air to the fuel reforming catalyst, and controls the fuel supply means and the secondary air supply means Control means, and the control means operates a fuel supply means and a secondary air supply means for supplying fuel and air to the fuel reforming catalyst to cause a combustion reaction of the fuel and air, and steam reforming in the fuel reforming catalyst In a structure that promotes the reaction Further, it is preferable that the secondary air supply means for supplying air to the fuel reforming catalyst is operated so as to obtain a stoichiometric to rich atmosphere in which the steam reforming reaction in the fuel reforming catalyst is promoted. It is. Thus, it is possible to provide a fuel reforming system for an internal combustion engine that can achieve excellent fuel efficiency improvement while efficiently suppressing deterioration of the fuel reforming catalyst.

  Furthermore, in the present invention, in a fuel reforming system that reacts a fuel of an internal combustion engine and at least a part of the exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen, the exhaust of the internal combustion engine A gas circulation channel, a fuel reforming catalyst disposed in the exhaust gas circulation channel, and a fuel that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation channel and supplies fuel to the fuel reforming catalyst A supply means, a secondary air supply means that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation passage and supplies air to the fuel reforming catalyst, and controls the fuel supply means and the secondary air supply means Control means, and the control means operates a fuel supply means and a secondary air supply means for supplying fuel and air to the fuel reforming catalyst to cause a combustion reaction of the fuel and air, and steam reforming in the fuel reforming catalyst In a structure that promotes the reaction Further, the secondary supplying air to the fuel reforming catalyst so as to achieve a space velocity that promotes the combustion reaction between the fuel and air in the fuel reforming catalyst and the steam reforming reaction in the fuel reforming catalyst. It is preferable that the air supply means be activated. Thus, it is possible to provide a fuel reforming system for an internal combustion engine that can achieve excellent fuel efficiency improvement while efficiently suppressing deterioration of the fuel reforming catalyst.

  Further, according to the present invention, in a fuel reforming system for reacting a fuel of an internal combustion engine and at least a part of an exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen, the exhaust of the internal combustion engine A gas circulation channel, a fuel reforming catalyst disposed in the exhaust gas circulation channel, and a fuel that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation channel and supplies fuel to the fuel reforming catalyst A supply means, a reed valve as a secondary air supply means disposed upstream of the fuel reforming catalyst in the exhaust gas circulation passage and supplying air to the fuel reforming catalyst, a fuel supply means and a secondary air supply Control means for controlling the means, and the control means operates the fuel supply means and the secondary air supply means for supplying the fuel and air to the fuel reforming catalyst to cause the fuel and air to undergo a combustion reaction. Promotes steam reforming reaction A configuration for further, it is preferable that the reed valve is configured to reduce the pressure in the reforming supply passage to supply air to the fuel reforming catalyst takes in outside air. Thus, a fuel reforming system for an internal combustion engine capable of realizing excellent fuel efficiency improvement while suppressing deterioration of the fuel reforming catalyst by causing the pressure reducing means having a simple configuration to function in the fuel reforming system is provided. be able to. Further, since the configuration is simple, there is an advantage that an increase in cost can be avoided.

  Furthermore, in the present invention, in a fuel reforming system that reacts a fuel of an internal combustion engine and at least a part of the exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen, the exhaust of the internal combustion engine A gas circulation channel, a fuel reforming catalyst disposed in the exhaust gas circulation channel, and a fuel that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation channel and supplies fuel to the fuel reforming catalyst A supply means, a secondary air supply means that is disposed upstream of the fuel reforming catalyst in the exhaust gas circulation passage and supplies air to the fuel reforming catalyst, and controls the fuel supply means and the secondary air supply means A control means, and a deterioration degree detection means that is disposed downstream of the fuel reforming catalyst in the exhaust gas circulation passage and detects the degree of deterioration of the fuel reforming catalyst, and the control means supplies fuel to the fuel reforming catalyst. And fuel supplier to supply air And the secondary air supply means is operated to cause the fuel and air to undergo a combustion reaction to promote the steam reforming reaction in the fuel reforming catalyst. The degree of deterioration of the fuel reforming catalyst is recovered in accordance with the secondary air supply amount-deterioration recovery degree map data indicating the relationship between the air supply amount and the degree of deterioration recovery of the fuel reforming catalyst and the input from the deterioration degree detecting means. It is preferable that the secondary air supply means for supplying air to the fuel reforming catalyst is operated so as to supply a secondary air supply amount of air. Thus, it is possible to provide a fuel reforming system for an internal combustion engine that can achieve excellent fuel efficiency improvement while efficiently suppressing deterioration of the fuel reforming catalyst.

  As mentioned above, although this invention was demonstrated with some forms, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention.

  That is, the configuration described in the fuel reforming system of each embodiment described above is not limited to each embodiment. For example, the configuration of each embodiment may be combined other than each embodiment described above, or the details of the configuration may be changed. You can do it.

  Further, for example, in each of the above-described embodiments, the internal combustion engine is exemplified as the fuel supply target and the exhaust recovery target. However, the present invention is not limited to this and can be applied to a fuel cell or the like.

1A, 1B, 1C Fuel reforming system 10 Engine 11 Cylinder 12 Combustion chamber 12a Intake port 12b Exhaust port 13 Intake valve 14 Exhaust valve 15 Piston 16 Spark plug 20 Intake pipe 21 Main fuel supply device 22 Intake control valve 30 Exhaust pipe 31 Exhaust Control valve 40 EGR pipe 41a Secondary air injection device 41b Reed valve 42 Reforming fuel injection device 43 Fuel reforming catalyst 44 Temperature detector 45 EGR cooler 46 EGR valve 47 Hydrogen concentration detector 50 Controller

Claims (8)

A fuel reforming system for reforming fuel to produce reformed gas containing hydrogen,
A reforming supply channel;
A fuel reforming catalyst disposed in the reforming supply channel;
A fuel supply means disposed on the upstream side of the fuel reforming catalyst in the reforming supply channel and configured to supply fuel to the fuel reforming catalyst;
A secondary air supply means disposed upstream of the fuel reforming catalyst in the reforming supply channel and supplying air to the fuel reforming catalyst;
Control means for controlling the fuel supply means and the secondary air supply means;
With
The secondary air control means has a reed valve,
The control means operates the fuel supply means and the secondary air supply means for supplying the fuel and the air to the fuel reforming catalyst to cause the fuel and the air to undergo a combustion reaction. Promote steam reforming reaction ,
The fuel is characterized in that the control means reduces the pressure in the reforming supply flow path so that the reed valve takes in external air and supplies the air to the fuel reforming catalyst. Reforming system. A fuel reforming system for reforming fuel to produce reformed gas containing hydrogen,
A reforming supply channel;
A fuel reforming catalyst disposed in the reforming supply channel;
A fuel supply means disposed on the upstream side of the fuel reforming catalyst in the reforming supply channel and configured to supply fuel to the fuel reforming catalyst;
A secondary air supply means disposed upstream of the fuel reforming catalyst in the reforming supply channel and supplying air to the fuel reforming catalyst;
Control means for controlling the fuel supply means and the secondary air supply means;
With
Further comprising a deterioration degree detecting means disposed downstream of the fuel reforming catalyst in the reforming supply channel and detecting the degree of deterioration of the fuel reforming catalyst;
The control means operates the fuel supply means and the secondary air supply means for supplying the fuel and the air to the fuel reforming catalyst to cause the fuel and the air to undergo a combustion reaction. Promote steam reforming reaction,
Secondary air supply amount-deterioration recovery degree map data showing the relationship between the secondary air supply amount of the secondary air supply means and the degree of deterioration recovery of the fuel reforming catalyst acquired in advance by the control means; The secondary supplying the air to the fuel reforming catalyst so as to supply a secondary air supply amount of air for recovering the deterioration degree of the fuel reforming catalyst in response to an input from the deterioration degree detecting means. Activating the air supply means
A fuel reforming system characterized by that. The fuel reforming system is a fuel reforming system that reacts a fuel of an internal combustion engine and at least a part of an exhaust of the internal combustion engine to reform the fuel to generate a reformed gas containing hydrogen,
The fuel reforming system according to claim 1 or 2 , wherein the reforming supply channel is an exhaust gas circulation channel of the internal combustion engine. A temperature detector for measuring the outlet side temperature of the fuel reforming catalyst,
The control means obtains the outlet temperature of the fuel reforming catalyst at which the steam reforming reaction in the fuel reforming catalyst acquired in advance is accelerated, and the outlet of the fuel reforming catalyst input from the temperature detector The outlet temperature of the fuel reforming catalyst input from the temperature detector is compared with the outlet temperature of the fuel reforming catalyst at which the steam reforming reaction in the fuel reforming catalyst is accelerated. The fuel reformer according to any one of claims 1 to 3 , wherein the secondary air supply means for supplying the air to the fuel reforming catalyst is operated when it is determined that the fuel reforming catalyst has been reached. Quality system. When the control means stops the operation of the fuel supply means so as not to supply the fuel to the fuel reforming catalyst, the secondary air supply means for supplying the air to the fuel reforming catalyst is operated. The fuel reforming system according to any one of claims 1 to 4, wherein: When the control means starts the operation of the fuel supply means so as to supply the fuel to the fuel reforming catalyst, the secondary air supply means for supplying the air to the fuel reforming catalyst is operated. The fuel reforming system according to any one of claims 1 to 4, wherein: The control means operates the secondary air supply means for supplying the air to the fuel reforming catalyst so as to obtain a stoichiometric to rich atmosphere in which the steam reforming reaction in the fuel reforming catalyst is promoted. The fuel reforming system according to any one of claims 1 to 6, characterized in that The control means causes the fuel reforming catalyst to have a space velocity that promotes a combustion reaction between the fuel and the air in the fuel reforming catalyst and a steam reforming reaction in the fuel reforming catalyst. The fuel reforming system according to any one of claims 1 to 7, wherein the secondary air supply means for supplying air is operated.

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