JP2007119315A - Fuel reforming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel reforming apparatus which can be simply controlled. <P>SOLUTION: The fuel reforming apparatus is equipped with a preheating unit 1 for preheating a mixed raw material fluid in which a hydrocarbon fuel to be a raw material to generate reformed gas containing hydrogen, oxygen or oxygen-containing gas and water or steam are mixed, a reforming unit 3 having a combustion catalyst 29 for combusting the mixed raw material fluid preheated at the preheating unit 1, and a reforming catalyst 31 for generating the reformed gas containing hydrogen by reforming the generated gas generated through the combustion catalyst 29, where the preheating unit 1 is thermally isolated from the reforming unit 3, and the mixed raw material fluid having been preheated in the preheating unit 1 is led to the reforming unit 3 from the preheating unit 1 through a mixed raw material fluid channel 9 disposed between the preheating unit 1 and the reforming unit 3. As a result, control of the fuel reforming apparatus can be simplified because the preheating unit 1 doubles the fuel preheater and the oxygen preheater for a reforming reactor, and thermal interference between the preheating unit 1 and the reforming unit 3 can be suppressed mutually. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel reformer, and more particularly to an internal heat type fuel reformer.

  The fuel reformer generates hydrogen necessary for a fuel cell system or the like. As one of the fuel reformers, an internal heat type that supplies heat obtained by burning a part of fuel with oxygen directly as part of heat necessary for a reforming reaction for generating hydrogen from a raw material. There is an internal heating type fuel reformer. The internal heat type fuel reformer includes a fuel preheater, an oxygen preheater for a reforming reactor, a reforming reactor, a carbon monoxide shifter (hereinafter referred to as a CO shifter), and a carbon monoxide selective oxidizer (hereinafter referred to as a carbon monoxide shifter). (Referred to as Patent References 1 to 3).

  The fuel preheater has a combustion catalyst, a heat transfer tube, and the like inside, and burns exhaust gas discharged from the fuel cell by the combustion catalyst, and preheats the fuel flowing through the heat transfer tube with this combustion heat. . Similar to the fuel preheater, the oxygen preheater for the reforming reactor also has a combustion catalyst, a heat transfer tube, etc., and the combustion catalyst burns exhaust gas discharged from the fuel cell, and this combustion heat passes through the heat transfer tube. Preheat the flowing oxygen or oxygen-containing gas. The reforming reactor transfers heat to exchange heat between the combustion catalyst, the reforming catalyst, and the reformed gas that has passed through the combustion catalyst or the reforming catalyst, and water or steam that is the raw material of the reformed gas. It has a heat pipe. Further, a CO shifter is arranged downstream from the reformed gas flow of the reforming reactor, and a CO selective oxidizer is arranged subsequently to the CO shifter.

  In addition, as a conventional fuel reformer, a fuel preheater, an oxygen preheater for reforming reactor, and a reforming reactor are not separately formed as in Patent Document 1, but Patent Documents 2, 3, etc. In order to reduce heat loss and reduce the size of the device, the preheater serves as a fuel preheater and an oxygen preheater for the reforming reactor, and preheats a raw material mixed gas in which fuel and oxygen or an oxygen-containing gas are mixed. It is proposed that the part that becomes the reforming reactor and the part that becomes the reforming reactor are housed in an integrated container, and an electric heater is installed between the part that becomes the preheater and the part that becomes the reforming reactor. ing.

JP 2003-123819 A (5th page, FIG. 1) JP 2001-106513 A (page 3-4, FIG. 2) International Publication No. WO 01/047800 (page 11, FIG. 1)

  By the way, in the fuel reformer having a configuration in which a fuel preheater, an oxygen preheater for reforming reactor, and a reforming reactor are separately formed as in Patent Document 1, a fuel preheater and an air preheater are respectively provided. In addition, the structure is complicated, and heat transfer between the fuel preheater, air preheater, and reforming reactor, in other words, control due to mutual thermal interference End up.

  On the other hand, in a fuel reforming apparatus having a configuration in which a preheater and a reforming reactor are integrally formed, as in Patent Documents 2 and 3, etc., a portion serving as a preheater and a reforming reactor are formed in an integral container. In other words, it is possible to simplify the configuration, for example, by reducing the number of installed combustion catalysts. However, even fuel reformers such as Patent Documents 2 and 3 cannot prevent complicated control due to heat transfer between the preheater and the reforming reactor. For this reason, there is a demand for a fuel reformer that can simplify the control.

  An object of the present invention is to simplify the control of a fuel reformer.

  The fuel reformer of the present invention includes a preheating unit for preheating a hydrocarbon fuel that is a raw material for generating a reformed gas containing hydrogen, a raw material mixed fluid in which oxygen or a gas containing oxygen, and water or steam are mixed. A combustion catalyst for combusting the raw material mixed fluid preheated by the preheating unit, and a reforming unit having a reforming catalyst for reforming the generated gas generated by the combustion catalyst to generate a reformed gas containing hydrogen. The preheating unit and the reforming unit are thermally isolated from each other, and the raw material mixed fluid preheated by the preheating unit is separated from the preheating unit via a raw material mixed fluid channel provided between the preheating unit and the reforming unit. The above-described problem is solved by adopting a configuration that is guided to the reforming unit.

  With such a configuration, a preheating unit that serves as both a fuel preheater and an oxygen preheater for the reforming reactor can be obtained, and heat exchange between the preheating unit and the reforming unit, in other words, thermal interference between each other. And the control of the fuel reformer can be simplified.

  Further, the reforming unit has heat exchange means for exchanging heat with the reformed gas from the reforming catalyst, and water or steam supplied to the preheating unit for the raw material mixed fluid is The heat exchange means guides the preheating unit. As a result, the heat of the reformed gas from the reforming catalyst of the reforming unit can be recovered in the water or steam supplied to the preheating unit for the raw material mixed fluid, so that the heat balance of the reforming unit 3 can be achieved. Thus, the control of the fuel reformer can be further simplified.

  Furthermore, water or steam supplied to the preheating unit for the raw material mixed fluid is guided to the preheating unit through the heat exchange means of the reforming unit, and preheated without passing through the heat exchange means of the reforming unit. It is set as the structure which has the water introduction flow path which leads directly to a unit. With such a configuration, it is possible to achieve a predetermined steam carbon ratio while suppressing the temperature of the reformed gas on the outlet side of the reforming catalyst of the reforming unit from becoming lower than a predetermined value or a predetermined range.

  Also, the fuel is combined with the air supplied to the preheating unit in a direction perpendicular to the direction of the air flow, and further, water vapor is combined with the gas mixed with the air and the raw material. A mixed fluid is formed. Thereby, the mixability of the air, fuel, and water used as a raw material mixed fluid can be improved.

  Further, at least one of a hydrocarbon fuel for the raw material mixed fluid, oxygen or a gas containing oxygen, and water or steam recovers heat released from at least one of the preheating unit and the reforming unit. It is set as the structure guide | induced to a preheating unit from a means. As a result, the surface temperature of the preheating unit can be lowered, and the thermal efficiency can be improved even when the fuel reformer is housed in one package.

  According to the present invention, the control of the fuel reformer can be simplified.

(First embodiment)
Hereinafter, a first embodiment of a fuel reformer to which the present invention is applied will be described with reference to FIGS. 1 to 3. FIG. 1 is a diagram schematically showing, in cross section, a preheating unit and a reforming unit in a schematic configuration of a fuel reformer to which the present invention is applied. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a cross-sectional view schematically showing the structure of the raw material mixed fluid conduit of the fuel reformer to which the present invention is applied.

  As shown in FIGS. 1 and 2, the fuel reformer of this embodiment is an internal heat type fuel reformer, a preheating unit 1 serving as a preheater for preheating the raw material, and a raw material by reforming reaction. A reforming unit 3 serving as a reformer for generating hydrogen from the carbon, a carbon monoxide shifter (hereinafter referred to as a CO shifter) 5, and a carbon monoxide selective oxidizer (hereinafter referred to as a CO selective oxidizer). ) 7 etc. The preheating unit 1 and the reforming unit 3 are installed at intervals to reduce heat transfer, that is, thermal interference. Between the preheating unit 1 and the reforming unit 3, fuel, air, and water are provided. Alternatively, a raw material mixed gas in which raw materials such as water vapor are mixed is connected by a raw material mixed fluid pipe 9 that leads the preheating unit 1 to the reforming unit 3.

  The preheating unit 1 preheats fuel, oxygen or oxygen-containing gas, water, or steam as raw materials, and has a combustion catalyst 11 and a heat transfer tube 13 as heat exchange means in an internal space 1a. Further, the preheating unit 1 is in a state where the space 1 a inside the preheating unit 1 is covered with a heat insulating material 15. The preheating unit 1 is connected to a fuel introduction pipe 17 for introducing fuel, an air introduction pipe 19 for introducing air as oxygen or an oxygen-containing gas, and a water introduction pipe 21 for introducing water. 19 and 21 are connected to the heat transfer tube 13. Further, the preheating unit 1 includes a combustion catalyst air introduction pipe 23 for introducing air to the combustion catalyst as oxygen or an oxygen-containing gas, and anode exhaust gas from a fuel cell (not shown) to which the fuel reformer supplies hydrogen. An anode exhaust gas introduction pipe 25 and the like are also connected.

  In the present embodiment, the air introduction conduit 19 joins the fuel introduction conduit 17 at a portion of the fuel introduction conduit 17 located outside the preheating unit 1. The water introduction pipe 21 is connected to an inlet portion of the heat transfer pipe 13 in which the fuel introduction pipe 17 is connected to the heat transfer pipe 13. A plurality of the heat transfer tubes 13 are installed between the inlet portion and the outlet portion, and are branched into two in FIGS. 1 and 2. The space 1a inside the preheating unit 1 is divided into two spaces by the combustion catalyst 11, and a heat transfer tube 13 is installed in one space. The combustion catalyst air introduction line 23 and the anode exhaust gas introduction line 25 communicate with the other space, that is, the space side where the heat transfer pipe 13 is not installed. One end of the raw material mixed fluid conduit 9 is connected to the outlet portion of the heat transfer tube 13.

  Further, the preheating unit 1 is connected with an exhaust gas conduit 27 for discharging combustion exhaust gas generated by combustion of anode exhaust gas by the combustion catalyst 11 in a portion of the space 1a on the side where the heat transfer tube 13 is installed. Yes.

  The reforming unit 3 generates hydrogen from the raw material mixed gas preheated by the preheating unit 1, and has a combustion catalyst 29, a reforming catalyst 31, a heat transfer tube 33 and the like in an internal space 3a. Further, the reforming unit 3 is in a state where the space 3 a inside the reforming unit 3 is covered with a heat insulating material 35. The reforming unit 3 is connected to a water introduction pipe 37 for introducing water, an end of the raw material mixed fluid pipe 9 opposite to the side connected to the preheating unit 1, and the like.

  In this embodiment, the space 3a inside the reforming unit 3 is divided into two spaces by the combustion catalyst 29 and the reforming catalyst 31, and the heat transfer tube 33 is installed in one space portion. Yes. And the other space part, ie, the space part on the side where the heat transfer pipe 33 is not installed, communicates with the end of the raw material mixed fluid pipe 9 opposite to the side connected to the preheating unit 1.

  As shown in FIG. 3, the raw material mixed fluid pipe 9 of the present embodiment is constructed by applying a heat insulating material around the outer surface of the inner pipe portion 9 a made of flexible piping and covering it with the heat insulating material portion 9 b. Thus, the raw material mixed fluid pipe 9 of the present embodiment allows the pipe to be thermally expanded and contracted due to a temperature change by using the inner pipe portion 9a as a flexible pipe. Moreover, it coat | covers with the heat insulating material part 9b, and also has the state which the outer pipe | tube part 9c coat | covered the outer side, and is covering with the heat insulating material part 9b, and is reducing the heat dissipation loss. In addition, by covering with the heat insulating material portion 9b or the like, even if a gas leak occurs in the inner pipe portion 9a, the heat insulating material portion 9b can suppress the gas leakage to the outside and improve safety.

  In the reforming unit 3, the combustion catalyst 29 and the reforming catalyst 31 pass through the raw material mixed fluid pipe 9 and the gas flowing into the space 3 a inside the reforming unit 3 in order from the combustion catalyst 29 to the reforming catalyst 31. It is installed to do. In other words, the reforming catalyst 31 is installed on the side of the space 3a where the heat transfer tube 33 is installed, and the combustion catalyst 29 is installed on the side of the space 3a where the heat transfer tube 33 is not installed.

  The water introduction pipe 37 is connected to the inlet portion of the heat transfer pipe 33 in the reforming unit 3, and is opposite to the side connected to the preheating unit 1 of the water introduction pipe 21 connected to the preheating unit 1. The end is connected to the inlet portion of the heat transfer tube 33 in the reforming unit 3. Therefore, in this embodiment, water or water vapor flows in the order of the water introduction pipe 37, the heat transfer pipe 33 in the reforming unit 3, the water introduction pipe 21, and the heat transfer pipe 13 in the preheating unit 1. .

  The generated hydrogen-containing gas that has flowed through the portion of the space 3a in which the heat transfer tube 33 is installed in the reforming unit 3 flows in the order of the CO shifter 5, the connecting flow path 38, and the CO selective oxidizer 7. Go. Note that the combustion catalysts 11 and 29, the reforming catalyst 31, the CO shifter 5, the CO selective oxidizer 7 and the like used in the present embodiment are the same as those of the conventional fuel reformer.

The operation of the fuel reformer having such a configuration and the features of the present invention will be described. Here, the hydrogen generation process will be described by taking as an example the case where the fuel of the fuel reformer of this embodiment, which is an internal heat type fuel reformer, is methane, which is the main component of natural gas. The reforming reaction of methane and steam at the reforming catalyst 31 in the reforming unit 3 is a sequential reaction from the left side to the right side of the following formula (1) and the following formula (2) as in the conventional fuel reformer. However, since it is an endothermic reaction as a whole, it is necessary to apply heat to maintain a reaction temperature of about 600 ° C.

CH ₄ + H ₂ O⇔CO + 3H ₂ (endothermic reaction) (1)
CO + H ₂ O ＣＯ CO ₂ + 3H ₂ (exothermic reaction) (2)

  In the internal heat type fuel reformer as in the present embodiment, the heat necessary for the endothermic reaction is combusted by the combustion catalyst 29 of the reforming unit 3 with the raw material fuel, here, a part of methane, by air. Cover with the heat you let me.

  However, unless the combustion amount of methane as a fuel is reduced as much as possible, the amount of generated hydrogen is reduced. On the other hand, when the facility or equipment for supplying hydrogen is a polymer electrolyte fuel cell system (hereinafter referred to as PEFC system), anode exhaust gas containing unreacted hydrogen comes out from the PEFC system body. Therefore, in the internal heat type fuel reformer, the heat of combustion of the anode exhaust gas is fed back to the fuel, air, and water as raw materials, thereby improving the overall thermal efficiency of the fuel reformer. The fuel reformer of this embodiment also includes a preheating unit 1 for feeding back the combustion heat obtained by burning such anode exhaust gas, and air from the combustion catalyst air introduction conduit 23 of the preheating unit 1 is provided. And the combustion catalyst 11 burn the anode exhaust gas from the anode exhaust gas introduction conduit 25, and preheat the fuel, air, and water flowing through the heat transfer tube 13 with the combustion heat.

  At this time, in the fuel reformer of this embodiment, unlike the conventional case, the air introduction pipe 19 joins the fuel introduction pipe 17 outside the preheating unit 1, and the water introduction pipe 21 is in the preheating unit 1. By joining the upstream end of the heat transfer tube 13 at the most upstream portion of the heat transfer tube 13 in the preheating unit 1, all of fuel, air, and water merge to become a raw material mixed fluid, and the heat transfer tube 13 flows in.

  Furthermore, in order to promote the mixing of fuel, air, and water, which are raw material mixed fluids, an air introduction pipe 19 merges perpendicularly to the fuel introduction pipe 17 outside the preheating unit 1, and each flow is In a state where they intersect vertically, fuel with a relatively low flow rate joins with air with a relatively high flow rate. Further, the water introduction pipe 21 from the reforming unit 3 joins the upstream end of the heat transfer pipe 13 in the preheating unit 1, so that air and fuel are mixed, and then the heat transfer pipe 33 of the reforming unit 3. The water from the water introduction pipe 37 which has become steam in the state of steam joins the mixed fluid of fuel and air in the state of steam. Thereby, mixing of these three fluids is promoted.

  In addition, in order to balance the heat of the reforming unit 3 such as setting the reformed gas flowing into the CO shifter 5 to an appropriate temperature, and for changing the water necessary for the reforming reaction in the reforming unit 3 to steam. A heat transfer pipe 33 is provided for recovering the heat of the gas that has passed through the reforming catalyst 31 of the reforming unit 3, that is, the reformed gas that exits from the outlet side of the reforming catalyst 31. The water from the water becomes steam by flowing through the heat transfer tube 33, and the water vapor generated in the heat transfer tube 33 is guided to the heat transfer tube 13 in the preheating unit 1 through the water introduction pipe 21.

  The raw material mixed gas preheated by flowing through the heat transfer tube 13 of the preheating unit 1 in this way flows into the reforming unit 3 via the raw material mixed fluid conduit 9. The raw material mixed gas that has flowed into the reforming unit 3 generates heat by burning part of the fuel by the air in the combustion catalyst 29 of the reforming unit 3, so that the reforming reaction also occurs and part of the fuel is hydrogen. Is converted to Thereafter, the gas from the combustion catalyst 29 flows into the reforming catalyst 31 to promote the reforming reaction, and becomes a hydrogen-rich reformed gas. Then, the hydrogen-rich reformed gas generated by the reforming unit 3 passes through the CO shift unit 5, the CO selective oxidizer 7, and the like, and is then guided to equipment and facilities such as a PEFC system that supplies hydrogen.

  In the preheating unit 1, the combustion gas generated by the combustion of the anode exhaust gas and air by the combustion catalyst 11 gives heat to the heat transfer tube 13, and then is released to the atmosphere as the combustion exhaust gas through the exhaust gas pipe 27. . Further, in the reforming unit 3, as the heat insulating material 35 surrounding the reforming unit 3, in order to reinforce the heat insulation more than the conventional fuel reforming device, the heat insulating material used in the conventional fuel reforming device is used. A heat insulating material with low thermal conductivity is used, or measures such as increasing the thickness of the heat insulating material are taken.

  Thus, in the fuel reforming apparatus of the present embodiment, the preheating unit 1 is configured to serve as both a fuel preheater and a reforming reactor oxygen preheater. The preheating unit 1 and the reforming unit 3 Are connected via a raw material mixed fluid conduit 9 through which the raw material mixed gas preheated by the preheating unit 1 flows, and is thermally isolated. Therefore, complicated heat transfer between the preheating unit 1 and the reforming unit 3, in other words, mutual thermal interference can be suppressed, and control of the fuel reformer can be simplified.

  Furthermore, in the fuel reformer of this embodiment, since the control of the fuel reformer can be simplified, the operation can be simplified and the controllability can be improved. In addition, in the fuel reforming apparatus of the present embodiment, the reforming unit 3 includes a heat transfer tube 33 serving as a heat exchanging means for exchanging heat with the reformed gas from the reforming catalyst 31, and mixing raw materials Water or steam supplied to the preheating unit 1 for fluid is led from the heat transfer pipe 33 of the reforming unit 3 to the preheating unit 1 through the water introduction pipe 37. Therefore, the heat of the reformed gas from the reforming catalyst 31 of the reforming unit 3 is recovered in the water or steam supplied to the preheating unit 1 for the raw material mixed fluid, so that the heat balance of the reforming unit 3 is achieved. Therefore, the control of the fuel reformer can be simplified.

  In addition, since the reforming unit 3 has a heat transfer tube 33 serving as a heat exchange means for exchanging heat with the reformed gas from the reforming catalyst 31, reforming in the reforming unit 3 is performed. The water necessary for the reaction, in other words, the water supplied to the preheating unit 1 is converted into the heat of combustion in the combustion catalyst 11 of the preheating unit 1 and the heat of the reformed gas from the reforming catalyst 31 of the reforming unit 3. Both heats can be changed to steam, and water necessary for the reforming reaction in the reforming unit 3 can be more reliably vaporized into steam. However, the heat of combustion of the anode exhaust gas can be used to obtain the latent heat of evaporation sufficient to change almost all the water necessary for the reforming reaction, that is, the raw material water, into steam, or the reforming catalyst 31 of the reforming unit 3. When it is not necessary to lower the temperature of the reformed gas from the water, the heat transfer pipe 33 is not provided in the reforming unit 3, and water or water vapor is directly guided from the water introduction pipe 37 to the heat transfer pipe 13 of the preheating unit 1. You can also

  By the way, in the conventional internal combustion type fuel reformer, since the steam flows around the reforming catalyst, there is a problem that the temperature distribution of the reforming catalyst is likely to occur, and a mixed fluid of fuel and air as a raw material is reduced. There is a problem in the mixing of raw materials due to the structure in which water is combined after preheating and the condition of laminar flow area. If there is a problem with the mixing property of the raw materials in this way, it becomes a factor of reducing the hydrogen generation capability of the fuel reformer.

  On the other hand, in the fuel reformer of the embodiment, among the fuel, air, and water that are the raw material mixed fluid, the direction of the flow of the fuel having a relatively low flow rate relative to the air having a relatively high flow rate The raw material mixed gas is mixed by combining water vapor with the gas in which the air and the fuel are mixed. For this reason, the mixability with the fuel, air, and water which are raw materials can be improved. In addition, the raw material mixed fluid flows into the combustion catalyst 29 and the reforming catalyst 31 of the reforming unit 3 in a state where the mixing property with the fuel, air, and water as raw materials is improved, so that the combustion catalyst 29 is improved. The temperature distribution in the direction perpendicular to the flow direction of the raw material mixed fluid of the catalyst 31 can be reduced. Further, since the temperature distribution in the direction perpendicular to the flow direction of the raw material mixed fluid between the combustion catalyst 29 and the reforming catalyst 31 can be reduced, the life of the combustion catalyst and the reforming catalyst can be extended.

  Furthermore, in a conventional internal combustion fuel reformer, when heating a fuel / air mixed gas, it is necessary to ensure safety against self-ignition, flashback, hydrocarbon fuel decomposition, etc., so a fuel preheater And an air preheater are formed separately, and each has a combustion part. For this reason, when the fuel preheater and the air preheater are formed separately, the number of component devices is relatively large. As described above, in the conventional internal combustion type fuel reformer, in order to improve safety against self-ignition, flashback and hydrocarbon fuel decomposition, the fuel preheater and the air preheater are individually separated. However, in such a configuration, there is a problem that the device configuration becomes complicated.

  On the other hand, as a result of various studies, the present inventors, when heating a mixed gas of fuel and air, which is a necessary condition for an internal heat type fuel reformer, must be a predetermined temperature or higher. It has been found that self-ignition and flashback do not occur, and that hydrocarbon fuel does not decompose if the composition ratio is optimized by adding fuel, air, water or steam. The fuel reformer of the present embodiment has a configuration corresponding to such knowledge, and since the fuel preheater and the air preheater can be made into one preheating unit 1, self-ignition, flashback, hydrocarbon fuel The device configuration can be simplified while improving the safety against disassembly and the like. Moreover, since the safety | security with respect to decomposition | disassembly of a hydrocarbon fuel, etc. can be improved, stability of hydrogen generation capability can be improved more. In addition, in the fuel reforming apparatus of the present embodiment, the number of component devices can be reduced and the apparatus configuration can be simplified, so that maintenance work for the fuel reforming apparatus can be simplified. Furthermore, since the control and the device configuration can be simplified, the cost can be reduced and the entire device can be made compact.

  In the present embodiment, the total amount of water or water vapor as a raw material is guided to the preheating unit 1 after flowing through the heat transfer tube 33 of the reforming unit 3. However, when almost the entire amount of water required for the reforming reaction is changed to steam, a certain amount of heat can be provided only by the combustion heat of the anode exhaust gas from the anode exhaust gas introduction pipe 25, that is, the raw material water is originally steam. Or the amount of heat obtained from the combustion heat of the anode exhaust gas, or depending on the extent to which the temperature of the reformed gas from the reforming catalyst 31 of the reforming unit 3 is lowered, It is also possible to adopt a configuration in which only a part of water or water vapor used as a raw material is passed through the heat transfer tube 33 without passing through the heat transfer tube 33.

(Second Embodiment)
Hereinafter, a second embodiment of the fuel reformer to which the present invention is applied will be described with reference to FIG. FIG. 4 is a diagram schematically showing, in cross section, a preheating unit and a reforming unit as a schematic configuration of a fuel reforming apparatus to which the present invention is applied. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and components different from those in the first embodiment are described.

  The difference between the fuel reforming apparatus of the present embodiment and the first embodiment is that the water used for the reforming reaction, that is, the water as the raw material, is added to the water introduction pipe 37 leading to the heat transfer pipe 33 of the reforming unit 3. In other words, a water introduction conduit 39 for guiding water as a raw material is provided on the upstream side of the heat transfer tube 13 of the preheating unit 1. In the fuel reforming apparatus of this embodiment, water and water vapor are guided from the water introduction pipe 37 to the heat transfer pipe 33 of the reforming unit 3 and the heat transfer pipe 13 of the preheating unit 1 through the water introduction pipe 21. In addition to the flow path, if necessary, water as a raw material is directly added to the heat transfer tube 13 of the preheating unit 1 without going through the reforming unit 3. That is, in the fuel reforming apparatus of the present embodiment, a part of the raw water is supplied directly from the water introduction line 39 to the heat transfer pipe 13 of the preheating unit 1 without passing through the heat transfer pipe 33 of the reforming unit 3. Is done.

  Here, the amount of water shared as a raw material for the fuel reformer is the steam carbon ratio of the entire internal heat type fuel reformer, that is, the amount of water vapor relative to the carbon in the fuel necessary to prevent carbon from being deposited. It plays the role of adjustment allowance to maintain the molar ratio within the proper range. In addition, the supply amount of water as a raw material from the water introduction pipe 37, that is, the supply amount of water to the heat transfer pipe 33 of the reforming unit 3, is the amount of reformed gas on the outlet side of the reforming catalyst 31 of the reforming unit 3. It is an amount necessary to keep the temperature within a predetermined value or a predetermined range. That is, the supply amount of water as a raw material from the introduction pipe 37 is determined from a necessary amount for maintaining the temperature of the reformed gas on the outlet side of the reforming catalyst 31 of the reforming unit 3 within a predetermined value or a predetermined range. Therefore, when the supply amount of water as a raw material from the water introduction pipe 37 does not reach a predetermined steam carbon ratio, water is supplied from the water introduction pipe 39 to the heat transfer pipe 13 of the preheating unit 1.

  Thereby, it is possible to achieve a predetermined steam carbon ratio while suppressing the temperature of the reformed gas on the outlet side of the reforming catalyst 31 of the reforming unit 3 from being lower than a predetermined value or a predetermined range.

  As described above, in the fuel reformer of this embodiment, a part of the water as a raw material is directly passed from the water introduction pipe 39 to the preheating unit 1 without passing through the heat transfer pipe 33 of the reforming unit 3 as necessary. The heat transfer tube 13 is supplied. For this reason, in the fuel reformer of this embodiment, the same effect as that of the first embodiment is obtained, and the temperature of the reformed gas at the outlet side of the reforming catalyst 31 of the reforming unit 3 is set to a predetermined value. Alternatively, with the amount of water necessary to maintain the predetermined range, the temperature of the reformed gas on the outlet side of the reforming catalyst of the reforming unit, even under operating conditions where the steam carbon ratio deviates from the predetermined value. Can be set to a predetermined steam carbon ratio while suppressing the lowering of the value from being lower than a predetermined value or a predetermined range. Furthermore, since the steam carbon ratio can be adjusted to a predetermined value, problems caused by carbon deposition can be suppressed, and the range of operating conditions can be expanded.

(Third embodiment)
Hereinafter, a third embodiment of a fuel reformer to which the present invention is applied will be described with reference to FIG. FIG. 5 is a diagram schematically showing, in cross section, a preheating unit and a reforming unit in a schematic configuration of a fuel reforming apparatus to which the present invention is applied. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The components different from those in the first and second embodiments will be described.

  The difference between the fuel reforming apparatus of the present embodiment and the first and second embodiments is that, similarly to the second embodiment, two water flow paths, that is, water introduction pipes 37 and 39 are used. In addition to the provision, an air introduction pipe 41 that is piped so as to collect the heat radiation from the preheating unit 1 is provided to serve as a heat radiation collection means. In the fuel reformer of the present embodiment, the air introduction pipe 41 is provided between both ends of the surface of the preheating unit 1, that is, the combustion catalyst air introduction pipe 23, the anode exhaust gas introduction pipe 25, and the like. It is attached from the end on the side to the end on the side where the exhaust gas pipe 27 and the like are provided. The end of the air introduction pipe 41 on the downstream side with respect to the air flow is connected to the fuel introduction pipe 17 as in the first and second embodiments.

  Thereby, even when the surface temperature of the preheating unit 1 is lowered and the fuel reformer is housed in one package, that is, when the fuel reformer is housed in one housing or the like, the thermal efficiency can be improved. Furthermore, since the surface temperature of the preheating unit 1 can be lowered, safety can be improved.

  As described above, in the fuel reforming apparatus of the present embodiment, the air introduction pipe 41 that is piped so as to collect the heat released from the preheating unit 1 is provided. For this reason, in the fuel reformer of this embodiment, in addition to the same effects as those of the first and second embodiments, the surface temperature of the preheating unit can be lowered, and one fuel reformer can be provided. Thermal efficiency can be improved even when it is housed in a package. In addition, safety can be improved.

  In the present embodiment, the air introduction pipe 41 is provided so as to collect the heat radiation from the preheating unit 1. However, the heat radiation from the preheating unit 1 may be used instead of the air introduction pipe depending on conditions. The heat radiation recovery means can be formed by piping a water introduction pipe, a fuel introduction pipe, or a combination of these pipes as appropriate.

  In the first and second embodiments, methane, air, and water are used as fuels, but various fuels that can generate hydrogen other than methane, oxygen that is a combustion agent other than air, or a gas containing oxygen. Depending on the fuel reformer, water or steam can be appropriately selected and used.

  The fuel reformer to which the present invention is applied is not limited to the configurations of the first and second embodiments, and can be formed in various configurations.

It is a figure which shows typically the schematic structure of 1st Embodiment of the fuel reformer formed by applying this invention in a cross section of a preheating unit and a reforming unit. It is sectional drawing in the II-II line of FIG. It is sectional drawing which shows typically the structure of the raw material mixing fluid pipe line in 1st Embodiment of the fuel reformer to which this invention is applied. It is a figure which shows typically the schematic structure of 2nd Embodiment of the fuel reformer formed by applying this invention in a cross section of a preheating unit and a reforming unit. It is a figure which shows typically the schematic structure of 3rd Embodiment of the fuel reformer to which this invention is applied in a cross section of a preheating unit and a reforming unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Preheating unit 3 Reforming unit 5 CO shift device 7 CO selective oxidizer 9 Raw material mixed fluid line 11, 29 Combustion catalyst 13, 33 Heat transfer pipe 15, 35 Heat insulating material 17 Fuel introduction line 19 Air introduction line 21, 37 Water introduction line 23 Air introduction line for combustion catalyst 25 Anode exhaust gas introduction line 27 Exhaust gas line 31 Reforming catalyst

Claims (5)

Preheating unit for preheating a hydrocarbon fuel, oxygen or a gas containing oxygen, and a raw material mixed fluid in which water or steam is mixed, and the raw material preheated by the preheating unit A reforming unit having a combustion catalyst for combusting a mixed fluid and a reforming catalyst for reforming a product gas generated by the combustion catalyst to generate a reformed gas containing hydrogen;
The preheating unit and the reforming unit are thermally isolated, and the raw material mixed fluid preheated by the preheating unit passes through a raw material mixed fluid channel provided between the preheating unit and the reforming unit. A fuel reformer led from the preheating unit to the reforming unit. The reforming unit has heat exchange means for exchanging heat with the reformed gas from the reforming catalyst, and water or steam supplied to the preheating unit for the raw material mixed fluid is the reforming unit. 2. The fuel reforming apparatus according to claim 1, wherein the fuel reforming apparatus is led from the unit heat exchange means to the preheating unit. Without introducing the water or water vapor supplied to the preheating unit for the raw material mixed fluid to the preheating unit via the heat exchange means of the reforming unit and the heat exchange means of the reforming unit. The fuel reformer according to claim 2, further comprising a water introduction channel that directly leads to the preheating unit. The fuel is combined with the air supplied to the preheating unit in a direction perpendicular to the direction of the air flow, and further, water vapor is combined with the gas in which the air and the fuel are mixed to mix the raw materials. The fuel reformer according to any one of claims 1 to 3, wherein a fluid is formed. At least one of a hydrocarbon fuel for a raw material mixed fluid, oxygen or a gas containing oxygen, and water or steam recovers heat released from at least one of the preheating unit and the reforming unit. The fuel reforming apparatus according to any one of claims 1 to 4, wherein the fuel reforming apparatus is guided to the preheating unit from a means.

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