JP5677513B2 - Kerosene reformer - Google Patents

Description

  The present invention relates to a reformer that reforms kerosene to produce a reformed gas containing hydrogen.

  In recent years, fuel cell cogeneration systems that can convert input energy into heat and electricity have been developed against the background of global environmental conservation. In this system, a hydrocarbon fuel such as kerosene is steam reformed by a reformer, and the produced reformed gas is supplied to a fuel cell to generate electricity. Further, in order to effectively use the heat generated by power generation, it is required to install this system in the vicinity of the user. Therefore, reducing the installation location by downsizing the system is also an important development factor.

  In general, when the fuel cell is a solid oxide fuel cell, the reformer includes a combustion section for supplying reforming heat, and a reforming section for performing a steam reforming reaction between hydrocarbon and steam. Yes. In order to improve the thermal efficiency and miniaturization of the reformer, an integrated reformer in which the components of the reforming unit are integrated has been proposed. For example, a multi-cylinder structure reformer is disclosed ( Patent Document 1).

JP 2003-300703 A

  In a conventional multi-cylindrical structure reformer, a reforming unit that performs an endothermic reaction is disposed outside a combustion cylinder that forms a high-temperature combustion unit, so that heat from the combustion unit is absorbed by the reforming unit. It had a cylindrical structure. Therefore, there has been a problem that the diameter of the reformer becomes large.

  An object of the present invention is to provide a fuel reformer having a multi-cylindrical structure that can be further downsized.

  The present invention provides the following kerosene reformer.

1) A reformer that reforms kerosene to produce reformed gas,
A combustor for burning kerosene;
A combustion cylinder having a cylindrical shape that forms a region through which combustion gas generated in the combustor flows;
A hollow cylindrical reforming catalyst layer disposed coaxially with the combustion cylinder inside the combustion cylinder; and
Including a first partition wall, which is a partition wall having a cylindrical portion disposed inside the inner peripheral surface of the reforming catalyst layer, for partitioning the region through which the combustion gas flows and the reforming catalyst layer,
The combustor is a surface combustion burner having a circular combustion surface;
Inner diameter of the cylindrical portion of the first partition wall, rather smaller than the diameter of the circular combustion surface,
Having a gap between the outer peripheral surface of the reforming catalyst layer and the inner peripheral surface of the combustion cylinder,
A second partition wall, which is a partition wall having a cylindrical shape, partitions the reforming catalyst layer and the space so that the outlet end of the reforming catalyst layer and the space can communicate with each other;
A water evaporator having a heat exchange structure that vaporizes water by heat exchange between the combustion gas and water, adjacent to the combustion cylinder on the downstream side of the reforming catalyst layer with respect to the flow direction of the combustion gas,
The water evaporator has a cylindrical shape and is arranged coaxially with the combustion cylinder;
The outer peripheral surface of the water evaporator and the outer peripheral surface of the cylindrical part of the first partition have the same diameter,
The outer peripheral surface of the water evaporator has a water vapor discharge hole that is a hole for discharging water vapor from the water evaporator,
A steam channel wall that is a wall connected to the outer peripheral surface of the water evaporator and the combustion cylinder, forming a steam channel that is a channel for supplying steam to the reforming catalyst layer from the steam discharge hole;
The water vapor channel wall includes a cylindrical portion having an inner peripheral surface having the same diameter as the inner peripheral surface of the second partition, and an annular portion serving also as a kerosene vaporization plate,
The kerosene reformer, wherein the heat exchange structure of the water evaporator includes a combustion gas passage extending in the axial direction of the water evaporator and a water evaporation region surrounding the combustion gas passage .

2 ) A gas dispersion plate is provided between the steam discharge hole and the reforming catalyst layer in the steam channel.
1 ) A kerosene reformer as described.

3 ) having a plurality of the gas dispersion plates,
Each of the plurality of gas dispersion plates has a plurality of holes coaxially with the combustion cylinder,
The number of the plurality of holes is larger in the upstream gas dispersion plate than in the flow of water vapor.
2) Kerosene reformer as described.
4 ) having a kerosene vaporization plate made of brass that vaporizes kerosene upstream of the dispersion plate in the water vapor flow path in the water vapor flow path;
A reformer for kerosene as described in 2 ) or 3 ).

  The present invention provides a fuel reformer having a multi-cylindrical structure that can be further downsized.

It is a longitudinal cross-sectional view which shows the basic composition of one Embodiment of the kerosene reformer of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. The kerosene reformer shown in FIG. 1 can perform not only reforming but also water evaporation and kerosene vaporization. In other words, the water evaporator and kerosene vaporizer are integrated into the reformer in a compact manner.

  The kerosene reformer has a combustor 1 for burning kerosene and a combustion cylinder 2 having a cylindrical shape. A combustion cylinder forms the area | region 3 which distribute | circulates the combustion gas generated with a combustor. The kerosene reformer has a hollow cylindrical reforming catalyst layer 4 inside the combustion cylinder. This reforming catalyst layer is disposed coaxially with the combustion cylinder. The kerosene reformer has a partition wall (referred to as a first partition wall) 5 that partitions a region through which combustion gas flows and a reforming catalyst layer. The first partition has a cylindrical portion 5a disposed inside the inner peripheral surface (the peripheral surface of the hollow portion) of the reforming catalyst layer. In the form shown in FIG. 1, the portion other than the cylindrical portion of the first partition is an annular portion 5 b. In this way, a multi-cylindrical structure is formed.

  In the reforming catalyst layer, endotherm occurs. That is, the reforming catalyst layer performs steam reforming or performs autothermal reforming in which the endotherm due to steam reforming exceeds the heat generation due to partial oxidation. A reformed gas containing hydrogen is produced by steam reforming or autothermal reforming.

  The catalyst used in the reforming catalyst layer can be appropriately selected from known catalysts that can promote such reforming reaction. For example, a Ni-based reforming catalyst or a Ru-based reforming catalyst is used as the type of catalyst. Examples of the shape of the reforming catalyst include a granular shape, a cylindrical shape, and a honeycomb shape.

  A cylindrical combustor 1 is provided at the upper portion of the combustion cylinder 2 and burns fuel so that the flame of the combustor is formed downward toward the inside of the combustion cylinder. In FIG. 1, the kerosene reformer is arranged in this way, and the upper side of the drawing coincides with the vertical upper side. The combustor is provided coaxially with the combustion cylinder 2. Kerosene is supplied to the combustor as combustion fuel. Combustion air is also appropriately supplied to the combustor.

  For example, a cylindrical premixed combustion type combustor having a kerosene vaporizer inside can be used as the combustor. This kerosene vaporizer is configured to vaporize kerosene for combustion by a heater provided in contact with the kerosene vaporizer or by combustion heat after the start of combustion. Furthermore, after forming the gas mixture of vaporization kerosene and combustion air, it is comprised so that combustion may be maintained by supplying a gas mixture to a combustion surface. This combustor is a surface combustion burner, and its combustion surface is circular.

  It is preferable to flow the reformed gas discharged from the reforming catalyst layer outside the reforming catalyst layer. Therefore, the kerosene reformer preferably has a gap (reformed gas flow path) 6 between the outer peripheral surface of the reforming catalyst layer and the inner peripheral surface of the combustion cylinder, and the reforming catalyst layer and the gap 6 Partition walls (referred to as second partition walls) 14. The second partition has a cylindrical shape. The second partition partitions the reforming catalyst layer and the gap 6 so that the outlet end of the reforming catalyst layer and the gap 6 can communicate with each other. In the form shown in FIG. 1, the lower end of the second partition wall is in contact with the bottom surface of the combustion cylinder 2, but the upper end of the second partition wall is not in contact with the first partition wall, and the annular portion of the first partition wall. A gap 13 is formed between 5b and the second partition wall and the reforming catalyst layer. With such a structure, the reforming catalyst layer outlet end (upper end) and the gap 6 can communicate with each other. A reforming catalyst is filled between the first partition and the second partition to form a reforming catalyst layer.

  With such a structure, the reformed gas generated in the reforming catalyst layer can be passed through the reformed gas channel (gap 6) formed outside the reforming catalyst layer. As a result, the sensible heat of the reformed gas can be transferred to the reforming catalyst layer via the second partition. Therefore, the reforming catalyst layer can be heated by the combustion gas from the inner periphery side of the reforming catalyst layer, and the reforming catalyst layer can be heated by the reforming gas from the outer periphery side of the reforming catalyst layer, which is an endothermic reaction. The amount of heat necessary for the reforming reaction can be efficiently given to the reforming catalyst layer.

  Preferably, the kerosene reformer includes the water evaporator 8 at a position adjacent to the combustion cylinder on the downstream side of the reforming catalyst layer in the flow direction of the combustion gas. The water evaporator has a heat exchange structure in which water is vaporized by heat exchange between combustion gas and water. With such a structure, it is possible to generate water vapor necessary for reforming by exchanging heat between the combustion gas transferred to the reforming catalyst layer 4 and water. By introducing this water vapor into the reforming catalyst layer 4, it is possible to increase the thermal efficiency.

  Further, the water evaporator can have a cylindrical shape, and the water evaporator can be arranged coaxially with the combustion cylinder. In particular, the diameter of the outer peripheral surface of the water evaporator 8 and the diameter of the outer peripheral surface of the cylindrical portion 5a of the first partition can be made the same. And the water vapor discharge hole 10 which is a hole which discharges | emits water vapor from a water evaporator can be provided in the outer peripheral surface of a water evaporator. Furthermore, the water vapor channel 11 which is a channel for supplying water vapor from the water vapor discharge hole to the reforming catalyst layer can be formed. For this purpose, it is possible to provide a steam flow path wall 12 which is a wall connected to the outer peripheral surface of the water evaporator and the combustion cylinder.

  With such a structure, water vapor can be supplied to the reforming catalyst layer without being routed by a separate pipe. As a result, it becomes possible to prevent the heat radiation due to the complicated structure and the handling.

  In the embodiment shown in FIG. 1, more specifically, the water evaporator has a shell-and-tube heat exchange structure, the tube side serves as a combustion gas flow path, and water evaporates on the shell side. A water vapor discharge hole 10 is provided in the upper part of the water evaporator. The steam flow path wall 12 connects the outer peripheral surface of the water evaporator and the combustion cylinder. The water vapor channel wall has a cylindrical portion 12a and an annular portion 12b. The inner peripheral surface of the cylindrical portion 12a has the same diameter as the inner peripheral surface of the second partition wall. The water vapor channel wall is provided coaxially with the combustion cylinder.

  Preferably, the kerosene reformer has a gas dispersion plate 7 between the steam discharge hole 10 and the reforming catalyst layer in the steam channel 11. It is preferable to use a plurality of gas dispersion plates. Preferably, the kerosene reformer has a kerosene vaporization plate 9 for vaporizing kerosene (liquid) upstream of the gas dispersion plate in the steam flow path 11 with respect to the flow of water vapor.

  In the illustrated embodiment, the dispersion plate has a plurality of holes coaxially with the combustion cylinder, and among the plurality of dispersion plates, the number of holes increases in the upstream dispersion plate with respect to the flow of water vapor. .

  With such a structure, the kerosene vapor generated in the kerosene vaporization plate 9 is entrained by the water vapor and becomes a mixed gas of water vapor and kerosene vapor. It becomes possible to distribute the layer 4 more evenly.

  Moreover, about the material of the kerosene vaporization board 9, heat conduction is improved by using brass, and it becomes possible to generate | occur | produce kerosene vapor | steam stably.

  In the form shown in FIG. 1, the annular gas dispersion plate 7 is arranged coaxially with the combustion cylinder. The kerosene vaporization plate also serves as the annular portion 12b of the water vapor channel wall. Therefore, the kerosene vaporization plate is annular and is arranged coaxially with the combustion cylinder.

  An inlet for fluid supplied to the kerosene reformer and an outlet for fluid discharged from the kerosene vaporizer can be provided as appropriate. The arrows in the figure indicate the direction of fluid flow.

  As an application form of the present invention, an internal reforming solid oxide fuel cell system having an internal reforming solid oxide fuel cell and the kerosene reformer can be exemplified. The internal reforming solid oxide fuel cell includes a solid oxide fuel cell (SOFC), a reformer that produces reformed gas to be supplied to the SOFC (referred to as an internal reformer), an SOFC, and an internal reforming fuel cell. And a housing for housing the quality device. The kerosene reformer is separate from the internal reformer. The internal reformer is disposed at a position where heat can be received from the SOFC by radiation or the like. The kerosene reformer is connected so that the reformed gas can be supplied to the anode of the SOFC.

  In the internal reforming SOFC system as described above, when the SOFC system is started up, the SOFC system is operated until the temperature of the internal reformer rises to a temperature at which the reforming gas can be generated from the internal reformer. In order to prevent oxidative degradation, it becomes possible to supply the reformed gas from the kerosene reformer to the SOFC. In addition, even when the SOFC system is stopped, after it becomes difficult to produce the reformed gas in the internal reformer, the temperature at which the reducing gas must be supplied to prevent the SOFC from being oxidized (for example, the SOFC temperature is 200 to 700 ° C.). Even when SOFC is present in the temperature range, the reformed gas can be supplied from the kerosene reformer.

  According to the present invention, since the reforming portion filled with the reforming catalyst is formed inside the combustion cylinder, the diameter of the reformer can be suppressed. As a result, it is possible to reduce the size of the reformer and to reduce the amount of heat insulating material disposed around the reformer for the purpose of improving the thermal efficiency of the reformer.

  Furthermore, a second partition is provided, and the reformed gas generated from the reforming catalyst layer is circulated between the second partition and the combustion cylinder, so that the sensible heat of the reformed gas is reduced by the second partition. Thus, heat can be transferred to the reforming catalyst layer, and the thermal efficiency of the reformer can be improved.

  In addition, a water evaporator installed on the downstream side of the reforming catalyst layer as viewed from the flow direction of the combustion gas is provided, and heat exchange is performed between the combustion gas transferred to the reforming catalyst layer and water. Thus, it is possible to increase the thermal efficiency by generating water vapor necessary for reforming and introducing this water vapor into the reforming catalyst layer.

DESCRIPTION OF SYMBOLS 1 Combustor 2 Combustion cylinder 3 Area | region 4 through which combustion gas distribute | circulates 4 Reformation catalyst layer 5 1st partition 5a Cylindrical part 5b of 1st partition 1st partition annular part 6 Space | gap (reformed gas flow path)
7 Gas dispersion plate 8 Water evaporator 9 Kerosene vaporization plate 10 Water vapor discharge hole 11 Water vapor flow channel 12 Water vapor flow channel wall 12a Water vapor flow channel wall cylindrical portion 12b Water vapor flow channel wall annular portion 13 Air gap 14 Second partition

Claims (4)

A reformer that reforms kerosene to produce reformed gas,
A combustor for burning kerosene;
A combustion cylinder having a cylindrical shape that forms a region through which combustion gas generated in the combustor flows;
A hollow cylindrical reforming catalyst layer disposed coaxially with the combustion cylinder inside the combustion cylinder; and
Including a first partition wall, which is a partition wall having a cylindrical portion disposed inside the inner peripheral surface of the reforming catalyst layer, for partitioning the region through which the combustion gas flows and the reforming catalyst layer,
The combustor is a surface combustion burner having a circular combustion surface;
Inner diameter of the cylindrical portion of the first partition wall, rather smaller than the diameter of the circular combustion surface,
Having a gap between the outer peripheral surface of the reforming catalyst layer and the inner peripheral surface of the combustion cylinder,
A second partition wall, which is a partition wall having a cylindrical shape, partitions the reforming catalyst layer and the space so that the outlet end of the reforming catalyst layer and the space can communicate with each other;
A water evaporator having a heat exchange structure that vaporizes water by heat exchange between the combustion gas and water, adjacent to the combustion cylinder on the downstream side of the reforming catalyst layer with respect to the flow direction of the combustion gas,
The water evaporator has a cylindrical shape and is arranged coaxially with the combustion cylinder;
The outer peripheral surface of the water evaporator and the outer peripheral surface of the cylindrical part of the first partition have the same diameter,
The outer peripheral surface of the water evaporator has a water vapor discharge hole that is a hole for discharging water vapor from the water evaporator,
A steam channel wall that is a wall connected to the outer peripheral surface of the water evaporator and the combustion cylinder, forming a steam channel that is a channel for supplying steam to the reforming catalyst layer from the steam discharge hole;
The water vapor channel wall includes a cylindrical portion having an inner peripheral surface having the same diameter as the inner peripheral surface of the second partition, and an annular portion serving also as a kerosene vaporization plate,
The kerosene reformer, wherein the heat exchange structure of the water evaporator includes a combustion gas passage extending in the axial direction of the water evaporator and a water evaporation region surrounding the combustion gas passage . The steam flow path, between the steam discharge hole and the reforming catalyst layer, kerosene reformer of claim 1 further comprising a gas distribution plate. A plurality of the gas dispersion plates;
Each of the plurality of gas dispersion plates has a plurality of holes coaxially with the combustion cylinder,
The kerosene reformer according to claim 2, wherein the number of the plurality of holes is larger on the upstream side of the gas dispersion plate with respect to the flow of water vapor. The kerosene reformer according to claim 2 or 3, further comprising a kerosene vaporization plate made of brass that vaporizes kerosene upstream of the dispersion plate in the water vapor flow path.

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