JP4657351B2 - Reformer - Google Patents

Description

  The present invention relates to a reforming apparatus, and more particularly to a reforming apparatus that prevents a reforming catalyst from dropping even when a member expands or contracts due to a temperature change.

  A fuel cell that is expected to spread in recent years is a device that introduces hydrogen and oxygen and generates electric power through these electrochemical reactions. Fuel cells require hydrogen for power generation, but they are relatively difficult to obtain because the infrastructure for supplying hydrogen itself is not widespread. Therefore, steam reforming of hydrocarbon-based raw materials such as city gas and kerosene is performed. In many cases, a fuel cell system is constructed in which a reformer that generates hydrogen-rich reformed gas is provided in the fuel cell. For example, in a small reformer that is installed in a fuel cell with an output of about 1 kW installed in a home, a plurality of tubes are arranged concentrically at intervals from the request for downsizing, and the inside of the innermost tube A multi-cylinder type that forms a hydrogen-rich reformed gas by forming a combustion chamber and passing the raw material and water vapor between the tubes outside the combustion chamber and contacting the catalyst at a high temperature (For example, refer to Patent Document 1).

JP 2008-63159 A (FIG. 1 etc.)

  In the above-described multi-cylinder reforming apparatus, the catalyst is generally supported on a spherical or cylindrical alumina support and filled in a flow path between the tubes, and the filled catalyst is prevented from falling. A perforated plate through which gas can flow is attached to the bottom of the tube. At this time, due to the structure of the multi-cylindrical reformer, the plurality of tubes arranged concentrically increases in temperature as they are arranged on the inner side. The extending length will be different. For this reason, it is preferable to fix the porous plate for preventing the fall of the catalyst to either one of the inner and outer cylinders forming the flow path. However, even when the perforated plate for preventing the fall of the catalyst is fixed to one of the inner and outer cylinders and not fixed to the other, the packed catalyst becomes a resistance when the cylinder once extended due to thermal expansion contracts as the temperature decreases. As a result, a force to push the porous plate relatively down is generated, the porous plate is bent, and the catalyst may fall out of the flow path between the inner and outer cylinders.

  In view of the above-described problems, an object of the present invention is to provide a reforming device that prevents a reforming catalyst from dropping even when a member expands or contracts due to a temperature change.

  In order to achieve the above object, the reforming apparatus according to the first aspect of the present invention reforms a hydrocarbon-based raw material r to have hydrogen as a main component, for example, as shown in FIGS. A reforming device 10 for generating a hydrogen-containing gas g; a heating device 12 for generating heat used for reforming the raw material r; and a first cylindrical member 16 and a first cylindrical member 16 inside. A flow path forming member 15 having a second cylindrical member 17 accommodated in the first cylindrical member 16, the heat generating device 12 being accommodated in the first cylindrical member 16, and the second cylindrical member 17. A flow path forming member 15 in which a raw material flow path 18 through which the raw material r flows is formed between the cylindrical member 17 and a reforming catalyst RC that promotes reforming of the raw material r, and is filled in the raw material flow path 18 A reforming catalyst RC; a receiving plate 31 that allows fluids r, s, and j to pass through while preventing the reforming catalyst RC from falling; A receiving plate 31 fixed to the cylindrical member 16 and not fixed to the second cylindrical member 17; and a reinforcing member 32 that suppresses deformation of the receiving plate 31 in the axial direction of the flow path forming member 15. A reinforcing member 32 fixed to the first tubular member 16 and the receiving plate 31; a reinforcing plate 32 having a receiving plate fixing portion 32s fixed to the receiving plate 31; and a reforming catalyst RC. It is formed in a flat plate shape having a cylindrical member fixing portion 32t fixed to the first cylindrical member 16 on the filled side.

  If comprised in this way, since it is a reinforcement member which suppresses a deformation | transformation of the receiving plate to the axial direction of a flow-path formation member, Comprising: It equips with a 1st cylindrical member and a receiving plate, By temperature change, Even if the tubular member expands and contracts, the receiving plate can be prevented from being deformed, and the reforming catalyst in the space surrounded by the flow path forming member and the receiving plate can be prevented from falling off. The reinforcing member is formed in a flat plate shape having a receiving plate fixing portion fixed to the receiving plate and a cylindrical member fixing portion fixed to the first cylindrical member on the side filled with the reforming catalyst. Therefore, the heat possessed by the first tubular member that has received the heat from the heat generating device and has risen in temperature can be transmitted to the reforming catalyst via the reinforcing member, and the reforming reaction of the raw material can be promoted. it can.

  Moreover, the reformer according to the second aspect of the present invention is, for example, as shown in FIG. 7, in the reformer 10A according to the first aspect of the present invention, the reinforcing member 32A is a first cylindrical shape. The first cylindrical member 16 is formed of a material having substantially the same linear expansion coefficient as that of the member 16, and the length in the axial direction of the first cylindrical member 16 is configured over the entire portion filled with the reforming catalyst RC.

  If comprised in this way, since the length of the reinforcement member in the axial direction of the 1st cylindrical member is comprised over the whole part with which the reforming catalyst is filled, it is from a 1st cylindrical member to a reinforcement member. The amount of heat transferred can be increased, and the reforming reaction of the raw material can be further promoted.

  Further, power generation is performed by an electrochemical reaction between the reformer according to the first or second aspect of the present invention and a hydrogen-containing gas generated by the reformer and an oxidant gas containing oxygen. It is good also as a fuel cell system provided with the fuel cell to perform.

  According to the present invention, since the reinforcing member for suppressing the deformation of the receiving plate in the axial direction of the flow path forming member is provided with the reinforcing member fixed to the first tubular member and the receiving plate, Even if the tubular member expands and contracts, the receiving plate can be prevented from being deformed, and the reforming catalyst in the space surrounded by the flow path forming member and the receiving plate can be prevented from falling off. The reinforcing member is formed in a flat plate shape having a receiving plate fixing portion fixed to the receiving plate and a cylindrical member fixing portion fixed to the first cylindrical member on the side filled with the reforming catalyst. Therefore, the heat possessed by the first tubular member that has received the heat from the heat generating device and has risen in temperature can be transmitted to the reforming catalyst via the reinforcing member, and the reforming reaction of the raw material can be promoted. it can.

It is a longitudinal cross-sectional view of the reformer which concerns on embodiment of this invention. It is a fragmentary longitudinal cross-sectional view around the flow-path formation member of the reformer which concerns on embodiment of this invention. It is the III-III arrow line view in FIG. It is a typical sectional view showing composition of a model of stress analysis. (A) is a figure which shows an Example model, (b) is a figure which shows a comparative example model. It is a stress distribution figure which shows the analysis result of an Example model. It is a stress distribution figure which shows the analysis result of a comparative example model. It is a fragmentary longitudinal cross-sectional view around the flow-path formation member of the modification of the reformer which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or similar members are denoted by the same or similar reference numerals, and redundant description is omitted.

  First, a reformer 10 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of the reformer 10. The reformer 10 is a multi-cylinder reformer in which a plurality of tubes are arranged concentrically at intervals from the viewpoint of achieving compactness, and a flow path through which a fluid passes is formed between the tubes. It is. The reformer 10 includes a burner 12 as a heat generating device for generating reforming heat used for steam reforming of the raw material gas r as a hydrocarbon-based raw material, and a raw material flow path through which the raw material gas r passes while receiving the reforming heat. 18, a reforming catalyst RC filled in the raw material flow path 18, and a receiving plate 31 that prevents the reforming catalyst RC from falling from the raw material flow path 18 (see FIGS. 2 and 3). And a reinforcing member 32 (see FIGS. 2 and 3).

  The raw material flow path 18 filled with the reforming catalyst RC typically constitutes a reforming unit 21. The reforming part 21 is a part that generates a semi-reformed gas j containing steam as a main component but containing about 10% by volume of carbon monoxide by steam reforming the raw material gas r. Downstream of the reforming unit 21, a carbon monoxide reduction unit 22 that generates a reformed gas g as a hydrogen-containing gas with a reduced carbon monoxide concentration from the semi-reformed gas j is provided. The carbon monoxide reducing unit 22 converts the carbon monoxide in the semi-reformed gas j into a modified gas h in which the carbon monoxide is reduced from the semi-reformed gas j, and a carbon monoxide reducing unit 22 in the modified gas h. A selective oxidation unit 24 that selectively oxidizes carbon oxide to generate a reformed gas g in which carbon monoxide is further reduced from the modified gas h. The reforming unit 21 and the carbon monoxide reduction unit 22 constitute a reformed gas generation unit 20.

  The hydrocarbon-based raw material (described in the present embodiment as the raw material gas r) is a general term for a hydrocarbon or a mixture containing hydrocarbon as a main component, and typically includes a chain of methane, ethane, or the like. Hydrocarbons (including natural gas) or hydrocarbon-based raw materials mainly composed of hydrocarbons such as methanol and petroleum products (kerosene, gasoline, naphtha, LPG, etc.). The semi-reformed gas j is a gas containing hydrogen as a main component, and contains 40% by volume or more, typically about 70 to 80% by volume of hydrogen. The hydrogen concentration of the semi-reformed gas j may be 80% by volume or more, for example, as long as it can be generated by an electrochemical reaction with oxygen when supplied to a fuel cell (not shown). The semi-reformed gas j typically contains about 10% by volume of carbon monoxide.

  The burner 12 is configured to generate reforming heat by burning a combustion fuel f as a combustion fuel. The burner 12 is housed inside a combustion chamber compartment cylinder 14 which is a cylindrical member made of stainless steel, and the combustion chamber 13 is formed by the space at the tip of the burner 12 being surrounded by the combustion chamber compartment cylinder 14. The burner 12 and the combustion chamber 13 constitute a combustion section 11. In the present embodiment, the combustion chamber partition tube 14 is disposed so that its axis is substantially vertical. The burner 12 is disposed in the combustion chamber partition tube 14 so that the flame is formed downward. The combustion chamber section cylinder 14 is closed at the upper end 14a and is fixed to the casing, and the lower end is an open end and is a free end so that contraction due to temperature change is not hindered. The side of the burner 12 opposite to where the flame is formed penetrates the upper end 14 a of the combustion chamber partition tube 14 and is connected to the air fuel introduction pipe 29. The air fuel introduction pipe 29 forms a flow path through which the combustion air a and the combustion fuel f flow. The combustion chamber section cylinder 14 is surrounded by a flow path forming member 15 around the side surface.

  2 and 3 together with FIG. 1, the details around the flow path forming member 15 will be described. FIG. 2 is a partial longitudinal sectional view of the flow path forming member 15. 3 is a view taken in the direction of arrows III-III in FIG. The flow path forming member 15 has an inner cylinder 16 as a first cylindrical member and an outer cylinder 17 as a second cylindrical member. Both the inner cylinder 16 and the outer cylinder 17 are formed of stainless steel. The inner cylinder 16 is formed of a cylindrical member that is slightly larger than the combustion chamber section cylinder 14, and is arranged so that its axis substantially coincides with the axis of the combustion chamber section cylinder 14. Thus, an exhaust gas passage 11r is formed between the outer side of the combustion chamber section cylinder 14 and the inner side of the inner cylinder 16 for flowing the exhaust gas e after the combustion fuel f is burned by the burner 12. The inner cylinder 16 has an upper end that extends outward in a cross section perpendicular to the axis and is fixed to another member (a CO reduction catalyst holding cylinder 19c (see FIG. 1 described later) in the present embodiment), and a lower end 16b that is a combustion chamber partition cylinder. It is closed below 14 and has a free end so that shrinkage due to temperature change is not hindered.

  The outer cylinder 17 is formed of a cylindrical member that is slightly larger than the inner cylinder 16, and is arranged so that its axis substantially coincides with the axis of the inner cylinder 16. The outer cylinder 17 has an upper end that extends toward the center in the direction perpendicular to the axis and is fixed to the outer surface of the inner cylinder 16 (see FIG. 1), and a lower end that opens at substantially the same position as the lower end of the inner cylinder 16. It is a free end so that shrinkage due to temperature change is not hindered. The position where the upper end of the outer cylinder 17 is fixed to the outer surface of the inner cylinder 16 is higher than the flame position of the burner 12 (see FIG. 1). By disposing the outer cylinder 17 so as to surround the inner cylinder 16, a raw material flow path 18 is formed between the outer surface of the inner cylinder 16 and the inner surface of the outer cylinder 17. In the present embodiment, the width of the raw material flow path 18 (the distance between the outer surface of the inner cylinder 16 and the inner surface of the outer cylinder 17 in the direction perpendicular to the axis) is formed to be about 5 to 8 mm.

  The raw material flow path 18 is filled with a reforming catalyst RC for promoting the steam reforming reaction of the raw material gas r. The reforming catalyst RC of the present embodiment is configured by filling a plurality of nickel supports or ruthenium supported on a spherical alumina support having a diameter of about 3 mm. By being configured in this way, a gap is formed between the spherical carriers of the reforming catalyst RC in the raw material flow path 18 so that the raw material gas r flows through the raw material flow path 18 through this gap. It has become. The carrier may be formed in a columnar shape or the like other than the spherical shape. The reforming catalyst RC is typically filled over substantially the entire axial length of the outer cylinder 17 (see FIG. 1). The portion filled with the reforming catalyst RC constitutes the reforming unit 21. Since the steam reforming reaction in the reforming unit 21 is an endothermic reaction, the combustion unit 11 is configured to generate reforming heat by burning the combustion fuel f. The positional relationship between the reforming unit 21 and the burner 12 is configured such that the flame of the burner 12 is positioned approximately at the center in the vertical direction of the reforming unit 21. With such a positional relationship, the entire reforming unit 21 can be heated.

  The receiving plate 31 is attached to the lower portion of the inner cylinder 16 so that the reforming catalyst RC configured as described above does not fall from the raw material flow path 18. The receiving plate 31 is formed in a donut shape in which a central portion of a circular flat plate is cut into a circular shape. The receiving plate 31 has a diameter at the center portion that is substantially equal to the outer diameter of the inner cylinder 16, and the outer diameter is larger than the inner diameter of the outer cylinder 17 so that a gap is formed between the outer periphery and the outer cylinder 17. It is formed small. The receiving plate 31 is typically fixed to the lower outer surface of the inner cylinder 16 around the central opening, but may be fixed to the lower end of the inner cylinder 16. On the surface of the receiving plate 31, a plurality of passage holes 31 h that are large enough to allow a fluid such as the raw material gas r to pass but not the reforming catalyst RC.

  The reinforcing member 32 is a member provided to prevent the receiving plate 31 from peeling off from the inner cylinder 16. The reason why the reinforcing member 32 is provided is as follows. In the reformer 10, a member that is at room temperature (ambient environmental temperature) when stopped is raised to a temperature suitable for a process in which the raw material gas r is reformed to the reformed gas g during operation. In particular, the reforming section 21 generally rises to about 800 ° C. At this time, the temperature of the inner cylinder 16 closer to the combustion unit 11 becomes higher than the temperature of the outer cylinder 17 disposed outside via the raw material flow path 18 (the raw material gas r that performs endothermic reaction flows), A temperature difference occurs between the inner cylinder 16 and the outer cylinder 17. Therefore, in consideration of thermal expansion and the temperature difference between the inner cylinder 16 and the outer cylinder 17, the flow path forming member 15 is configured at the lower end at the free end, and the receiving plate 31 is fixed to the inner cylinder 16. The cylinder 17 is not fixed. However, even if such measures against thermal expansion are taken, the receiving plate 31 may be peeled off from the inner cylinder 16 and the reforming catalyst RC may drop off. Although it is difficult to specify the cause clearly, the present inventors have conducted intensive research. As a result, when the reforming device 10 is operated and the operating temperature rises, the inner cylinder 16 and the outer cylinder 17 are thermally expanded. Accordingly, the position of the receiving plate 31 is lowered and the reforming catalyst RC is also lowered by gravity. When the reforming apparatus 10 is stopped and the temperature is lowered from this state, the inner cylinder 16 and the outer cylinder 17 contract. Along with this, the position of the receiving plate 31 is raised, and the position of the reforming catalyst RC supported by the receiving plate 31 is also raised, but the rise is prevented between the spherical carriers of the filled reforming catalyst RC. Is generated, and the stress to cause the rising receiving plate 31 to be relatively pushed down (stress that causes the portion where the receiving plate 31 is fixed to the inner cylinder 16 to be damaged) is internal like a cantilever beam. 1 of the cause that occurs in the part fixed to the tube 16 To obtain a finding that is considered to.

  In view of the above circumstances, the reinforcing member 32 includes a receiving plate fixing side 32s as a receiving plate fixing portion fixed to the receiving plate 31, and a cylinder as a cylindrical member fixing portion fixed to the outer surface of the inner cylinder 16. It is formed in a flat plate shape having a fixed member fixing side 32t. The receiving plate fixing side 32s and the cylindrical member fixing side 32t are not only strictly linear sides but can be viewed as linear sides as a whole even if there are protrusions in the middle (mostly linear) Which is the side of). In the present embodiment, the reinforcing member 32 is formed in a rectangular flat plate shape. This is because, in the present embodiment, the upper surface of the receiving plate 31 and the outer surface of the inner cylinder 16 are orthogonal to each other, and processing is easy when the rectangular flat plate shape is used. However, as long as the reinforcing member 32 has the receiving plate fixing side 32s and the cylindrical member fixing side 32t, the reinforcing member 32 may be formed on a flat plate other than a rectangle, for example, a triangle or other polygons. By being formed in a flat plate, it is possible to reduce the hindrance of filling the reforming catalyst RC into the raw material flow path 18 and the flow of the raw material gas r.

  Further, eight reinforcing members 32 are provided so as to equally divide the raw material flow path 18 in the circumferential direction in a plan view (see FIG. 3). By attaching the reinforcing member 32 equally in the circumferential direction, the stress generated in the receiving plate 31 when the inner cylinder 16 contracts can be evenly dispersed. Note that the number of reinforcing members 32 to be installed is not limited to eight, and may be appropriately determined in consideration of the size of the raw material flow path 18 and the length that the inner cylinder 16 extends due to thermal stress.

  A typical construction procedure around the flow path forming member 15 is as follows. First, the cylindrical member fixing side 32t of the reinforcing member 32 is fixed to the lower outer surface of the inner cylinder 16. Next, the outer cylinder 17 is put on the inner cylinder 16, and the upper portion of the outer cylinder 17 is fixed to the outer surface of the inner cylinder 16. Thereafter, the inner cylinder 16 to which the outer cylinder 17 is attached is turned upside down, and the formed raw material flow path 18 is filled with the reforming catalyst RC. Then, the receiving plate 31 is placed on the receiving plate fixing side 32s of the reinforcing member 32 and fixed to the outer surface of the inner cylinder 16 and the receiving plate fixing side 32s. The receiving plate 31 may be fixed to the reinforcing member 32 by welding using the passage hole 31h of the receiving plate 31. For example, a protrusion that can pass through the passage hole 31h is formed on the receiving plate fixing side 32s of the reinforcing member 32, and when the receiving plate 31 is placed on the reinforcing member 32, the protrusion protrudes from the passage hole 31h. It is preferable to weld the protruding protrusions so as to melt the reinforcing member 32 and the receiving plate 31 firmly. Further, the fixing of the receiving plate 31 to the inner cylinder 16 is typically performed by spot-welding midpoints between adjacent reinforcing members 32 (with this embodiment, spot welding is performed at eight locations). Will be). By using spot welding, the labor of welding can be reduced. Alternatively, from the viewpoint of further reducing the generated stress on the receiving plate 31 at the connection portion with the inner cylinder 16, the number of spot weldings may be increased or all-around welding may be performed.

  The configuration of the reformer 10 will be described with reference mainly to FIG. 1 again. The lower end of the outer cylinder 17 is an opening. The reforming part 21 communicates with the transformation part 23 through this opening. On the other hand, the upper end of the outer cylinder 17 is closed, and a raw material gas introduction pipe 26 for introducing the raw material gas r into the reforming section 21 is connected to a part of the upper end. A space not filled with the reforming catalyst is formed in the upper part of the reforming unit 21 so that the source gas r introduced through the source gas introduction pipe 26 reaches the entire upper part of the outer cylinder 17. The source gas introduction pipe 26 extends in the direction opposite to the combustion unit 11 (that is, outward). A reforming water pipe 25, which will be described in detail later, is connected to the raw material gas introduction pipe 26.

  The shift section 23 is configured by providing a shift catalyst on the outer periphery of the inner cylinder 16 above the reforming section 21 while leaving the upper portion of the inner cylinder 16. The shift catalyst also covers the upper part of the outer cylinder 17. The portion where the shift catalyst covers the outer cylinder 17 is partitioned by the outer cylinder 17 and is not in contact with the reforming unit 21. As described above, the transformation section 23 communicates with the reforming section 21 through the opening at the lower end of the outer cylinder 17. The shift catalyst is a catalyst that promotes a shift reaction in which carbon monoxide contained in the semi-reformed gas j generated by the steam reforming reaction in the reforming section 21 is reacted with water, and typically iron-chromium. A system shift catalyst, a copper-zinc shift catalyst, a platinum shift catalyst, or the like is used. Further, the shape of the shift catalyst is preferably granular, columnar, honeycomb, or monolithic in order to efficiently perform the shift reaction. The metamorphic reaction shifts carbon monoxide to carbon dioxide. The modification reaction is an exothermic reaction.

  The selective oxidation unit 24 is configured by providing a selective oxidation catalyst on the outer periphery of the inner cylinder 16 above the shift unit 23. The boundary between the selective oxidation unit 24 and the transformation unit 23 may be partitioned by punching metal or the like, but the selective oxidation unit 24 and the transformation unit 23 are configured to communicate with each other. The selective oxidation catalyst is a catalyst that promotes a selective oxidation reaction in which carbon monoxide contained in the shift gas h generated by the shift reaction in the shift section 23 is reacted with oxygen, typically a platinum-based selective oxidation catalyst, A ruthenium-based selective oxidation catalyst, a platinum-ruthenium-based selective oxidation catalyst, or the like is used. Further, the shape of the selective oxidation catalyst is preferably a granular shape, a cylindrical shape, a honeycomb shape, or a monolith shape in order to efficiently perform a selective oxidation reaction. The selective oxidation reaction is an exothermic reaction.

  The shift catalyst and the selective oxidation catalyst are held by a CO reduction catalyst holding cylinder 19c that is a cylindrical member coaxial with the combustion chamber partition cylinder 14 and the like. In other words, the shift catalyst is filled between a part of the inner cylinder 16 and the outer cylinder 17 and the CO reduction catalyst holding cylinder 19c, and selective oxidation is performed between the upper part of the inner cylinder 16 and the CO reduction catalyst holding cylinder 19c. Packed with catalyst. The CO reducing catalyst holding cylinder 19 c extends also below the shift unit 23 and covers the lower part of the reforming unit 21. The CO reducing catalyst holding cylinder 19 c below the shift section 23 is formed to be slightly larger than the outer cylinder 17. The lower end 19b of the CO reducing catalyst holding cylinder 19c is closed. The lower end of the outer cylinder 17 is disposed so as not to contact the lower end 19b of the CO reduction catalyst holding cylinder 19c. As a result, the reforming unit 21 and the transformation unit 23 communicate with each other. A quasi-reformed gas flow path 19 through which the quasi-reformed gas j flows is formed between the outer side of the outer cylinder 17 and the inner side of the CO reduction catalyst holding cylinder 19c below the shift portion 23. The quasi-reformed gas flow path 19 extends radially outward so that the quasi-reformed gas j is distributed directly below the shift catalyst and over the entire lower surface of the shift catalyst. The size of the CO reduction catalyst holding cylinder 19c that is slightly larger than the outer cylinder 17 may be determined as appropriate in consideration of the flow rate of the semi-reformed gas j flowing through the semi-reformed gas flow path 19.

  A selective oxidation air introduction pipe 27 that introduces selective oxidation air c into the selective oxidation unit 24 is connected to the CO reduction catalyst holding cylinder 19 c at the selective oxidation unit 24 immediately adjacent to the shift unit 23. The selective oxidation air introduction pipe 27 extends outward. Further, the reformed gas pipe 28 for leading the reformed gas g is connected to the CO reducing catalyst holding cylinder 19c at the selective oxidation unit 24 on the side opposite to the side adjacent to the shift unit 23. The reformed gas pipe 28 extends outward.

  The reforming water pipe 25 is arranged as follows. From the upper side of the selective oxidation unit 24, it contacts the outside of the CO reduction catalyst holding cylinder 19 c, and the outer side of the CO reduction catalyst holding cylinder 19 c is spirally wound downward from above the selective oxidation unit 24. When it is spirally wound downward and reaches a position about 2/3 from the top of the transformation section 23, it is separated from the CO reducing catalyst holding cylinder 19c and further turned upward to be connected to the raw material gas introduction pipe 26. To do. The reforming water pipe 25 communicates with the reforming unit 21 by connecting the reforming water pipe 25 to the raw material gas introduction pipe 26. As described above, the reforming water pipe 25 is disposed at a position adjacent to the selective oxidation unit 24 and the shift unit 23 so as to receive heat from the carbon monoxide reduction unit 22 of the reformed gas generation unit 20. When the reforming water pipe 25 is arranged in this way, the reforming water s flows from the side of the selective oxidation unit 24 to the side of the shift unit 23 and before flowing into the raw material gas introduction pipe 26, the selective oxidation unit 24 and the shift unit. It receives heat from 23 and changes from liquid to gas. As shown in FIG. 1, it is assumed that a part of the reforming water pipe 25 is disposed so as to pass through the selective oxidation unit 24 and / or the transformation unit 23 and to contact the inner cylinder 16. This is preferable because the amount of heat increases.

  The outer periphery of the transformation unit 23 and the reforming unit 21 below the lowermost part of the reforming water pipe 25 (in this embodiment, about 2/3 from the top of the transformation unit 23) is covered with a heat insulating material 46. . The outer circumferences of the transformation section 23 and the selective oxidation section 24 above the heat insulating material 46 are covered with a heat insulating material 47. Since each part 21, 23, 24 is covered with the heat insulating materials 46, 47, each part 21, 23, 24 can be maintained at a temperature suitable for reaction during operation, and the temperature of the outer periphery of the reformer 10 Can be made lower than the temperature of each part 21, 23, 24, and contribute to burn prevention and the like. The heat insulating materials 46 and 47 are covered with a surface material 48, and the appearance of the reformer 10 is formed in a substantially cylindrical shape.

  With continued reference to FIGS. 1 to 3, the operation of the reformer 10 will be described. When the reformer 10 starts operation, the combustion fuel f is supplied to the burner 12 in the reformer 10 and the combustion air a is also supplied to the burner 12. When the combustion fuel f and the combustion air a are supplied to the burner 12, the burner 12 is ignited. As a result, the temperature of the reforming unit 21 is increased, and the free end side is extended as the temperature of the combustion chamber partition cylinder 14, the inner cylinder 16, and the outer cylinder 17 is increased. At this time, the inner cylinder 16 and the outer cylinder 17 that are both formed of the same material do not have the same temperature, and therefore the amount of elongation due to thermal expansion is different. However, although the receiving plate 31 is fixed to the inner cylinder 16, Since it is not fixed to the cylinder 17, no thermal stress is generated on the receiving plate 31 due to the temperature difference between the inner cylinder 16 and the outer cylinder 17. The exhaust gas e generated by the combustion in the burner 12 flows through the exhaust gas passage 11r and is discharged out of the system. When the temperature of the reforming apparatus 10 increases, a reforming water pump (not shown) is activated to feed the reforming water s to the reforming water pipe 25.

  The reforming water s receives heat from the carbon monoxide reduction unit 22 through the reforming water pipe 25 and reaches the raw material gas introduction pipe 26 to receive steam (this steam is also reforming water). Therefore, hereinafter, the reforming water s that has become steam is also referred to as “steam s”. When the steam s is supplied to the reforming unit 21 and the inside of the reforming unit 21 is in a steam atmosphere, the source gas r is supplied to the source gas introduction pipe 26. The water vapor s and the raw material gas r introduced into the raw material gas introduction pipe 26 are mixed in the raw material gas introduction pipe 26 and reach the reforming section 21. In the reforming unit 21, the hydrocarbon in the raw material gas r and the steam s vaporized from the reforming water s flow through the gap of the reforming catalyst RC while obtaining reforming heat from the combustion unit 11 (steam reforming). Reaction), semi-reformed gas j containing hydrogen and carbon monoxide is generated. The produced semi-reformed gas j passes through the passage hole 31h of the receiving plate 31 and is sent to the shift unit 23 in order to reduce the carbon monoxide concentration.

  In the semi-reformed gas j sent to the shift unit 23, the generated carbon monoxide reacts with the remaining water vapor (the shift reaction) to become hydrogen and carbon dioxide. That is, in the metamorphic gas h generated in the metamorphic section 23, carbon monoxide is reduced and hydrogen and carbon dioxide are increased compared to the semi-reformed gas j. Although the shift gas h has a lower carbon monoxide concentration than the semi-reformed gas j, it usually contains about 5,000 to 10,000 ppm of carbon monoxide during steady operation, so The shift gas h generated in the shift unit 23 to reduce the carbon oxide concentration is sent to the selective oxidation unit 24. When the modified gas h is sent to the selective oxidation unit 24, the selective oxidation air c is supplied to the selective oxidation unit 24 by a selective oxidation air blower (not shown). In the modified gas h sent to the selective oxidation unit 24, the remaining carbon monoxide reacts with oxygen in the supplied selective oxidation air c (selective oxidation reaction) to become carbon dioxide. The reformed gas g produced by the selective oxidation reaction contains about 10 ppm or less of carbon monoxide in steady operation. The reformed gas g having such a carbon monoxide concentration is typically supplied to a fuel cell (not shown) via the reformed gas pipe 28.

  In the steady operation of the reformer 10, the reforming unit 21, the shift unit 23, and the selective oxidation unit 24 are in a state where the temperatures are suitable for the reactions in the respective units. The temperature of each part at the time of steady operation is about 550 ° C. to 800 ° C. for the reforming unit 21, about 160 ° C. to 280 ° C. for the transformation unit 23, and about 100 ° C. to 250 ° C. for the selective oxidation unit. When each part 21, 23, 24 has not reached the temperature during steady operation at the start of the reformer 10, the composition of the reformed gas g led to the reformed gas pipe 28 is not stable, Contains high concentrations of carbon monoxide. Therefore, the reformed gas g whose composition is not stable may be guided to the combustion unit 11 and burned as the combustion fuel f.

  When the operation of the reformer 10 is stopped, the supply of the combustion fuel f to the burner 12 is stopped, and the combustion of the burner 12 is stopped. At the same time, the supply of the reforming water s, the raw material gas r, and the selective oxidation air c to the reformer 10 is stopped. When the combustion of the burner 12 is stopped, the heating of the reforming unit 21 is stopped, and the temperature of the inner cylinder 16 and the outer cylinder 17 decreases with time and shrinks. At this time, it is considered that the frictional force of the reforming catalyst RC carrier acts in a direction in which the receiving plate 31 fixed to the lower portion of the shrinking inner cylinder 16 is relatively pushed down, and the connection portion between the receiving plate 31 and the inner cylinder 16 Although the stress is generated, the reinforcement member 32 is provided, so that the deformation of the receiving plate 31 due to the stress is suppressed. As described above, in the reforming apparatus 10 according to the present embodiment, even if expansion and contraction due to thermal stress occurs due to repeated operation and stoppage, the reinforcing member 32 prevents the receiving plate 31 from being damaged, and the reforming catalyst RC is It is prevented from falling off the raw material flow path 18. For reference, an analysis model of stress generated in the receiving plate 31 is shown below.

  FIG. 4 shows a configuration as a model for stress analysis. FIG. 4A is a model according to the present embodiment (hereinafter referred to as “example model”), and FIG. 4B is a model according to a comparative example (hereinafter referred to as “comparative example model”). In the embodiment model shown in FIG. 4A, the protrusion formed on the receiving plate fixing side 32s of the reinforcing member 32 (not shown in FIG. 4, see FIG. 2) is modified from the passage hole 31h of the receiving plate 31. The catalyst RC (see FIG. 2) is ejected to the side not filled, and the projecting projections are welded so as to melt to form welding points W32 (8 locations in total), and the midpoint between the adjacent reinforcing members 32 Are fixed to the inner tube 16 by spot welding at a welding point W16 (total of 8 locations). In the embodiment model shown in FIG. 4A, for convenience, the stress at the welding point W32 is the upper surface of the receiving plate 31 in contact with the receiving plate fixing side 32s (see FIG. 2) (the side where the reforming catalyst RC is filled). Instead, it occurs on the lower surface of the receiving plate 31 (the side not filled with the reforming catalyst RC). On the other hand, in the comparative example model shown in FIG. 4B, the welding point W32 provided in the example model shown in FIG. 4A is not provided, and the receiving plate 31 and the inner cylinder 16 are welded. It is assumed that only point welding is performed at point W16 (total of 8 locations).

  As a premise for analyzing the stress, the pressure p applied to the receiving plate 31 when the receiving plate 31 in the comparative example model shown in FIG. We will estimate. Each analysis model is considered under the following conditions. A fixed portion W16v in the axial direction at the welding point W16 has a length of 0.2 mm and a width of 2.0 mm, and a fixed portion W16h in the radial direction has a length of 0.5 mm and a width of 2.0 mm. Further, the radial fixed portion W32h at the welding point W32 has a length of 1.5 mm and a width of 2.0 mm. Further, the passage hole 31h of the receiving plate 31 is ignored, the shape of the fixing portion of each welding point W16, W32 is not directly considered, and the restraint (fixation) of each welding point W16, W32 is completely fixed. Assume. When the reforming apparatus 10 is operated, the temperature of the reforming unit 21 is 700 ° C., and when the reforming apparatus 10 is stopped, when the operation and the stop are repeated about 1000 times at normal temperature (ambient environment temperature), the receiving plate 31 is Applying the above conditions to the actual result of damage (actual experience), back-calculating the stress and strain acting on the backing plate 31 at this time, assuming a stress-strain diagram, conducting elasto-plastic analysis, and low cycle fatigue The pressure p was searched so as to obtain stress and strain values at the time of breakage. As a result, it was concluded that in the comparative example model shown in FIG. 4B, the failure stress 245 MPa occurs at the welding point W16 when the pressure p applied to the receiving plate 31 is 0.7 MPa. An analysis result of stress generated in the fixed portion (welding point) when the pressure p = 0.7 MPa is applied to the receiving plate 31 is shown below.

  In FIG. 5, the analysis result of the stress which arises in the welding points W16 and W32 (refer FIG. 4A) of an Example model is shown. In addition, in the figure, the part of the receiving plate 31 between two adjacent welding points W16 out of the eight welding points W16 is extracted and shown. As can be seen from the figure, in the example model, the stress at the fixed point of the welding point W16 where the greatest stress occurs is 60 MPa. This is less than a quarter of the failure stress (245 MPa). Moreover, the stress of the part of the welding point W32 is about 20 MPa, and is less than 1/10 of the failure stress (245 MPa). As can be seen from the analysis result, the effect of suppressing the breakage of the receiving plate 31 is remarkable in the example model.

  In FIG. 6, the analysis result of the stress which arises in the welding point W16 (refer FIG.4 (b)) of a comparative example model is shown. In the case of this comparative example model, as in the case of the example model (see FIG. 5), the portion of the receiving plate 31 between the two adjacent welding points W16 out of the eight welding points W16 is extracted. Show. As can be seen from the figure, in the comparative example model, the range in which the stress is generated is wider than that in the example model (see FIG. 5), centering on the fixed point portion of the welding point W16 where the maximum stress is 245 MPa. . As can be seen from the analysis result, in the comparative example model, the possibility of the receiving plate 31 being damaged due to repeated operation and stop of the reformer 10 is higher than that in the example model (see FIG. 5).

  Next, with reference to FIG. 7, a reformer 10A according to a modification of the embodiment of the present invention will be described. FIG. 7 is a partial longitudinal sectional view around the flow path forming member 15 of the reforming apparatus 10A. The difference between the reformer 10A and the reformer 10 (see FIG. 2) is that the length of the reinforcing member 32A in the axial direction is filled with the reforming catalyst RC in the axial direction of the flow path forming member 15. It is a point that covers the whole part. Further, the reinforcing member 32A is formed of a material having substantially the same linear expansion coefficient as that of the inner cylinder 16. The material having substantially the same linear expansion coefficient is a material having a relationship that the inner cylinder 16 and the reinforcing member 32A are not damaged by thermal stress even if they thermally expand. In the present embodiment, the inner cylinder 16 and the reinforcing member 32A are formed of the same material. Since the other configuration of the reformer 10A is the same as that of the reformer 10 (see FIG. 2), description thereof is omitted. In the reformer 10A, the length of the reinforcing member 32A formed of the same material as the inner cylinder 16 in the axial direction of the inner cylinder 16 (the length of the cylindrical member fixing side 32At) is filled with the reforming catalyst RC. Since it is over the entire portion, the heat of the inner cylinder 16 can be efficiently transmitted to the reforming catalyst RC via the reinforcing member 32A while avoiding the generation of excessive stress during expansion and contraction due to thermal expansion. The steam reforming reaction of the raw material gas r can be further promoted. The fixing portion of the reinforcing member 32A with the cylindrical member fixing side 32At and the outer surface of the inner cylinder 16 may be the entire longitudinal direction, or may be fixed with an appropriate interval. In any case, from the viewpoint of increasing heat transfer from the inner cylinder 16 to the reinforcing member 32A, it is preferable that the cylindrical member fixing side 32At and the inner cylinder 16 are in contact with each other as much as possible.

10, 10A reformer 12 heat generating device 15 flow path forming member 16 inner cylinder (first cylindrical member)
17 Outer cylinder (second cylindrical member)
18 Raw material flow path 31 Receiving plate 32, 32A Reinforcing member 32s Receiving plate fixed side 32t, 32At Cylindrical member fixed side RC Reforming catalyst g Reforming gas r Raw material gas s Reforming water

Claims (2)

A reformer for reforming a hydrocarbon-based raw material to produce a hydrogen-containing gas mainly containing hydrogen;
A heat generating device for generating heat used for reforming the raw material;
A flow path forming member having a first tubular member and a second tubular member that accommodates the first tubular member therein, wherein the heat generating device is disposed inside the first tubular member. And a flow path forming member in which a raw material flow path through which the raw material flows is formed between the first cylindrical member and the second cylindrical member;
A reforming catalyst for promoting reforming of the raw material, the reforming catalyst filled in the raw material flow path;
A receiving plate that allows fluid to pass through while preventing the reforming catalyst from falling, the receiving plate being fixed to the first cylindrical member and not fixed to the second cylindrical member;
A reinforcing member that suppresses deformation of the receiving plate in the axial direction of the flow path forming member, the reinforcing member being fixed to the first tubular member and the receiving plate;
The reinforcing member has a receiving plate fixing portion fixed to the receiving plate, and a cylindrical member fixing portion fixed to the first cylindrical member on the side filled with the reforming catalyst. A reformer. The reinforcing member is formed of a material having substantially the same linear expansion coefficient as that of the first cylindrical member, and the axial length of the first cylindrical member is filled with the reforming catalyst. Composed throughout;
The reformer according to claim 1.

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