U.S. patent application number 12/297653 was filed with the patent office on 2009-03-12 for heat exchange reformer unit and reformer system.
This patent application is currently assigned to TOKYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Kenji Kimura, Takashi Shimazu, Tomohisa Wakasugi.
Application Number | 20090064579 12/297653 |
Document ID | / |
Family ID | 38537793 |
Filed Date | 2009-03-12 |
United States Patent
Application |
20090064579 |
Kind Code |
A1 |
Wakasugi; Tomohisa ; et
al. |
March 12, 2009 |
HEAT EXCHANGE REFORMER UNIT AND REFORMER SYSTEM
Abstract
In a heat exchange reformer unit, a reforming passage supporting
reform catalyst for inducing reforming reactions and a combustion
passage supporting oxidizing catalyst for combustion are disposed
adjacent to each other with a plate portion interposed
therebetween. Heat-exchanging passages of the reforming passage
that produce reformate gas that contains hydrogen from supplied
reformation material, and heat-exchanging passages of the
combustion passage that supply heat, which is generated by
catalytically burning supplied fuel, to the reforming passage
constitute a parallel-flow heat exchanger. Reformation material
guide passages for introducing reformation material into the
heat-exchanging passages in a predetermined direction, and mixed
gas guide passages for introducing fuel into the heat-exchanging
passages in a direction intersecting the gas flow direction in the
reformation material guide passages, are provided upstream of the
heat-exchanging passages in a gas flow direction.
Inventors: |
Wakasugi; Tomohisa;
(Aichi-ken, JP) ; Shimazu; Takashi; (Aichi-ken,
JP) ; Kimura; Kenji; (Aichi-ken, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
TOKYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi ,Aichi-ken
JP
|
Family ID: |
38537793 |
Appl. No.: |
12/297653 |
Filed: |
April 24, 2007 |
PCT Filed: |
April 24, 2007 |
PCT NO: |
PCT/IB2007/001056 |
371 Date: |
October 20, 2008 |
Current U.S.
Class: |
48/76 |
Current CPC
Class: |
C01B 2203/0822 20130101;
Y02P 20/128 20151101; B01J 19/0093 20130101; B01J 2219/2486
20130101; C01B 2203/0827 20130101; B01J 19/249 20130101; B01J
2219/2465 20130101; B01J 2219/2485 20130101; B01J 2219/247
20130101; C01B 2203/0233 20130101; B01J 2219/00835 20130101; C01B
3/384 20130101; B01J 2219/2479 20130101; B01J 2219/2453 20130101;
B01J 2219/2487 20130101; B01J 2219/00873 20130101; B01J 2219/2458
20130101; B01J 2219/1928 20130101; C01B 2203/141 20130101; Y02P
20/10 20151101; B01J 2219/00783 20130101; C01B 2203/066 20130101;
B01J 2219/00822 20130101; B01J 2219/00824 20130101; B01J 2219/2481
20130101; C01B 2203/0811 20130101; C01B 2203/12 20130101 |
Class at
Publication: |
48/76 |
International
Class: |
C10J 3/68 20060101
C10J003/68 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 24, 2006 |
JP |
2006-119751 |
Apr 28, 2006 |
JP |
2006-126407 |
Claims
1-23. (canceled)
24. A heat exchange reformer unit, comprising: a reforming section,
in which reforming catalyst for inducing reforming reactions is
supported, for producing reformate gas, which contains hydrogen,
from supplied reformation material through reforming reactions
including steam-reforming reaction; a heating section, which is
disposed adjacent to the reforming section with a separation wall
interposed between the heating section and the reforming section so
as to cause a gas flow in the same direction as that of a gas flow
in the reforming section, and in which oxidizing catalyst for
catalytic combustion is supported, for supplying, to the reforming
section, heat generated by catalytically burning supplied fuel; a
reformation material-introducing section, one end of which serves
as a supply port of the reformation material, and the other end of
which is integral with a reformation material inflow side of the
reforming section; a fuel-introducing section, one end of which
serves as a supply port of the fuel, and the other end of which is
integral with a fuel inflow side of the heating section, for
introducing the fuel into the heating section in a flow direction
different from a flow direction of the reformation material in the
reformation material-introducing section; and a cross-flow heat
exchanging section which is constituted by the reformation material
introducing section and the fuel-introducing section, and which
does not support a catalyst, wherein a plurality of the reforming
sections and a plurality of the heating sections are provided,
wherein the plurality of the reforming sections and the plurality
of the heating sections are stacked with at least part of the
plurality of the reforming sections being adjacent to at least part
of the plurality of the heating sections.
25. The heat exchange reformer unit according to claim 24, wherein
the entirety of the fuel-introducing section is a region in which
no oxidizing catalyst is supported.
26. The heat exchange reformer unit according to claim 24, wherein
the reformation material-introducing section is provided for each
of the reforming sections, and surface planes of the reformation
material supply ports are substantially on the same plane, and
wherein the fuel-introducing section is provided for each of the
heating sections, and surface planes of the fuel supply ports are
substantially on the same plane.
27. The heat exchange reformer unit according to claim 26, wherein
the heat exchange reformer unit comprises: a plurality of reforming
section-forming plate members each including: a first flat-shaped
plate portion; and a first standing wall provided on the first
flat-shaped plate portion in a standing condition for guiding the
reformation material in a predetermined direction, wherein a first
heat exchanging section constituting the reforming section together
with another plate portion is formed of part of the first
flat-shaped plate portion, and wherein a reformation material guide
section constituting the reformation material-introducing section
together with another plate portion is formed of part of the first
flat-shaped plate portion and the first standing wall that is
formed adjacent to a reformation material supply-side of the first
heat exchanging section; and a plurality of heating section-forming
plate members each including: a second flat-shaped plate portion;
and a second standing wall provided on the second flat-shaped plate
portion in a standing condition for guiding the fuel in a direction
intersecting the predetermined direction, wherein a second heat
exchanging section constituting the heating section together with
another plate portion is formed of part of the second flat-shaped
plate portion, and wherein a fuel guide section constituting the
fuel-introducing section together with another plate portion is
formed of part of the second flat-shaped plate portion and the
second standing wall that is formed adjacent to a fuel supply-side
of the second heat exchanging section, wherein the reforming
section-forming plate members and the heating section-forming plate
members are stacked in a predetermined pattern.
28. The heat exchange reformer unit according to claim 26, further
comprising: a reformation material manifold, defining a collection
space to which the reformation material supply ports of the
plurality of the reformation material-introducing sections are
open, for distributing the reformation material to the plurality of
the reformation material-introducing sections; and a fuel manifold,
defining a collection space to which the fuel supply ports of the
plurality of the fuel-introducing sections are open, for
distributing the fuel to the plurality of the fuel-introducing
sections.
29. The heat exchange reformer unit according to claim 24, further
comprising: a reformate gas-discharging section, one end of which
serves as a discharge port of the reformate gas, and the other end
of which is integral with a reformate gas outflow side of the
reforming section; and a combustion exhaust gas-discharging
section, one end of which serves as a discharge port of combustion
exhaust gas of the heating section, and the other end of which is
integral with a combustion exhaust gas outflow side of the heating
section, for introducing the combustion exhaust gas to the
discharge port of the combustion exhaust gas in a flow direction
different from a flow direction of the reformate gas in the
reformate gas-discharging section.
30. The heat exchange reformer unit according to claim 24, wherein
a plurality of the reforming sections are provided, and the at
least one heating section is provided so that the heating sections
is less in number than the reforming sections.
31. The heat exchange reformer unit according to claim 24, wherein
a plurality of the reforming sections and a plurality of the
heating sections are provided, wherein the plurality of the
reforming sections and the plurality of the heating sections are
stacked so that a surface area of a region in which the reforming
catalyst is supported is greater than a surface area of a region in
which the oxidizing catalyst is supported.
32. The heat exchange reformer unit according to claim 24, wherein
a plurality of the reforming sections and a plurality of the
heating sections are provided, wherein the plurality of the
reforming sections and the plurality of the heating sections are
stacked so that an amount of the reforming catalyst supported is
greater than an amount of the oxidizing catalyst supported.
33. The heat exchange reformer unit according to claim 24, wherein
a plurality of the reforming sections and a plurality of the
heating sections are provided, wherein the plurality of the
reforming sections and the plurality of the heating sections are
stacked so that a total volume of the plurality of the reforming
sections is greater than a total volume of the plurality of heating
sections.
34. A heat exchange reformer unit, comprising: a plurality of
reforming sections for producing reformate gas, in which reforming
catalyst for inducing reforming reactions is supported; and a
plurality of heating sections, in which reforming catalyst for
catalytic combustion is supported, for supplying heat, which is
generated by catalytically burning supplied fuel, to the reforming
sections, wherein a number of the heating sections is less in
number than a number of the reforming sections.
35. The heat exchange reformer unit according to claim 34, wherein
the heat exchange reformer unit includes a part in which two layers
of the reforming sections are stacked per one layer of the heating
section.
36. The heat exchange reformer unit according to claim 34, wherein
the heat exchange reformer unit includes a part in which three
layers of the reforming sections are stacked per one layer of the
heating section.
37. The heat exchange reformer unit according to claim 34, wherein
the heat exchange reformer unit includes a part in which four or
more layers of the reforming sections are stacked per one layer of
the heating section.
38. The heat exchange reformer unit according to claim 34, further
comprising a heat transfer-promoting portion for promoting heat
transfer from the heating section to the adjacent reforming
section.
39. The heat exchange reformer unit according to claim 38, wherein
the heat transfer-promoting portion is provided in any one of or
each of the reforming section and the heating section in a standing
condition, wherein the heat transfer-promoting portion is a
standing wall extending from one of separation walls of adjacent
reforming section and heating section to the other separation
wall.
40. The heat exchange reformer unit according to claim 39, wherein
the standing wall is thicker than the separation wall between the
reforming section and the adjacent heating section.
41. The heat exchange reformer unit according to claim 38, wherein
the heat transfer-promoting portion has a thermal conductivity
greater than that of a material of which separation walls forming
the heating section are made.
42. The heat exchange reformer unit according to claim 38, wherein
the heat transfer-promoting portion is formed near the vicinity of
a supply port of reformation material for producing reformate
gas.
43. A reformer system, comprising: the heat exchange reformer unit
according to claim 34; and a water supply system for supplying
water to the reforming section of the heat exchange reformer
unit.
44. A heat exchange reformer unit, comprising: a plurality of
reforming sections for producing reformate gas, in which reforming
catalyst for inducing reforming reactions is supported; and a
plurality of heating sections, in which reforming catalyst for
catalytic combustion is supported, for supplying heat, which is
generated by catalytically burning supplied fuel, to the reforming
reactions, wherein the plurality of the reforming sections and the
plurality of the heating sections are stacked so that a surface
area of a region in which the reforming catalyst is supported is
greater than a surface area of a region in which the oxidizing
catalyst is supported.
45. The heat exchange reformer unit according to claim 44, wherein
the heat exchange reformer unit includes a part in which two layers
of the reforming sections are stacked per one layer of the heating
section.
46. The heat exchange reformer unit according to claim 44, wherein
the heat exchange reformer unit includes a part in which three
layers of the reforming sections are stacked per one layer of the
heating section.
47. The heat exchange reformer unit according to claim 44, wherein
the heat exchange reformer unit includes a part in which four or
more layers of the reforming sections are stacked per one layer of
the heating section.
48. The heat exchange reformer unit according to claim 44, further
comprising a heat transfer-promoting portion for promoting heat
transfer from the heating section to the adjacent reforming
section.
49. The heat exchange reformer unit according to claim 48, wherein
the heat transfer-promoting portion is provided in any one of or
each of the reforming section and the heating section in a standing
condition, wherein the heat transfer-promoting portion is a
standing wall extending from one of separation walls of adjacent
reforming section and heating section to the other separation
wall.
50. The heat exchange reformer unit according to claim 49, wherein
the standing wall is thicker than the separation wall between the
reforming section and the adjacent heating section.
51. The heat exchange reformer unit according to claim 48, wherein
the heat transfer-promoting portion has a thermal conductivity
greater than that of a material of which separation walls forming
the heating section are made.
52. The heat exchange reformer unit according to claim 48, wherein
the heat transfer-promoting portion is formed near the vicinity of
a supply port of reformation material for producing reformate
gas.
53. A reformer system, comprising: the heat exchange reformer unit
according to claim 44; and a water supply system for supplying
water to the reforming section of the heat exchange reformer
unit.
54. A heat exchange reformer unit, comprising: a plurality of
reforming sections for producing reformate gas, in which reforming
catalyst for inducing reforming reactions is supported; and a
plurality of heating sections, in which reforming catalyst for
catalytic combustion is supported, for supplying heat, which is
generated by catalytically burning supplied fuel, to the reforming
reactions, wherein the plurality of the reforming sections and the
plurality of the heating sections are stacked so that an amount of
the reforming catalyst supported is greater than an amount of the
oxidizing catalyst supported.
55. The heat exchange reformer unit according to claim 54, wherein
the heat exchange reformer unit includes a part in which two layers
of the reforming sections are stacked per one layer of the heating
section.
56. The heat exchange reformer unit according to claim 54, wherein
the heat exchange reformer unit includes a part in which three
layers of the reforming sections are stacked per one layer of the
heating section.
57. The heat exchange reformer unit according to claim 54, wherein
the heat exchange reformer unit includes a part in which four or
more layers of the reforming sections are stacked per one layer of
the heating section.
58. The heat exchange reformer unit according to claim 54, further
comprising a heat transfer-promoting portion for promoting heat
transfer from the heating section to the adjacent reforming
section.
59. The heat exchange reformer unit according to claim 58, wherein
the heat transfer-promoting portion is provided in any one of or
each of the reforming section and the heating section in a standing
condition, wherein the heat transfer-promoting portion is a
standing wall extending from one of separation walls of adjacent
reforming section and heating section to the other separation
wall.
60. The heat exchange reformer unit according to claim 59, wherein
the standing wall is thicker than the separation wall between the
reforming section and the adjacent heating section.
61. The heat exchange reformer unit according to claim 58, wherein
the heat transfer-promoting portion has a thermal conductivity
greater than that of a material of which separation walls forming
the heating section are made.
62. heat exchange reformer unit according to claim 58, wherein the
heat transfer-promoting portion is formed near the vicinity of a
supply port of reformation material for producing reformate
gas.
63. A reformer system, comprising: the heat exchange reformer unit
according to claim 54; and a water supply system for supplying
water to the reforming section of the heat exchange reformer
unit.
64. A heat exchange reformer unit, comprising: a plurality of
reforming sections for producing reformate gas, in which reforming
catalyst for inducing reforming reactions is supported; and a
plurality of heating sections, in which reforming catalyst for
catalytic combustion is supported, for supplying heat, which is
generated by catalytically burning supplied fuel, to the reforming
reactions, wherein the plurality of the reforming sections and the
plurality of the heating sections are stacked so that a total
volume of the plurality of the reforming sections is greater than a
total volume of the plurality of heating sections.
65. The heat exchange reformer unit according to claim 64, wherein
the heat exchange reformer unit includes a part in which two layers
of the reforming sections are stacked per one layer of the heating
section.
66. The heat exchange reformer unit according to claim 64, wherein
the heat exchange reformer unit includes a part in which three
layers of the reforming sections are stacked per one layer of the
heating section.
67. The heat exchange reformer unit according to claim 64, wherein
the heat exchange reformer unit includes a part in which four or
more layers of the reforming sections are stacked per one layer of
the heating section.
68. The heat exchange reformer unit according to claim 64, further
comprising a heat transfer-promoting portion for promoting heat
transfer from the-heating section to the adjacent reforming
section.
69. The heat exchange reformer unit according to claim 68, wherein
the heat transfer-promoting portion is provided in any one of or
each of the reforming section and heating section in a standing
condition, wherein the heat transfer-promoting portion is a
standing wall extending from one of separation walls of adjacent
reforming section and heating section to the other separation
wall.
70. The heat exchange reformer unit according to claim 69, wherein
the standing wall is thicker than the separation wall between the
reforming section and the adjacent heating section.
71. The heat exchange reformer unit according to claim 68, wherein
the heat transfer-promoting portion has a thermal conductivity
greater than that of a material of which separation walls forming
the heating section are made.
72. The heat exchange reformer unit according to claim 68, wherein
the heat transfer-promoting portion is formed near the vicinity of
a supply port of reformation material for producing reformate
gas.
73. A reformer system, comprising; the heat exchange reformer, unit
according to claim 64; and a water supply system for supplying
water to the reforming section of the heat exchange reformer
unit.
74. A reformer system, comprising: the heat exchange reformer unit
according to claim 24; and a water supply system for supplying
water to the reforming section of the heat exchange reformer unit.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat exchange reformer
unit in which reforming reactions are caused by which reformate gas
that contains hydrogen is obtained from reformation material, such
as hydrocarbon, with heat supplied from a heating section to a
reforming section. The present invention also relates to a reformer
system including such a heat exchange reformer unit.
[0003] 2. Description of the Related Art
[0004] A cross-flow heat exchange fuel reformer is available in
which reforming passages for producing gas that contains hydrogen
by reforming hydrocarbon material and combustion passages for
burning fuel gas to supply heat, which is used in reforming
reactions, to the reforming passages are alternately formed (see
Japanese Patent Application Publication No. 2004-244230
(JP-A-2004-244230)). JP-A-2004-244230 describes a technology for
setting a region in which catalyst is not supported between plates
so that the distribution of heat generation caused by combustion
reactions and the distribution of heat absorption by reforming
reactions in the regions between the plates are adjusted to each
other.
[0005] Although, in the cross-flow heat exchange fuel reformer
according to the related art, the way to match the region in which
a lot of heat is generated by combustion reactions, and the region
in which a lot of heat is absorbed by reforming reactions is
devised, there is room for improvement to enhance the heat exchange
efficiency by matching the endothermic region and the exothermic
region. In addition, because, in a fuel reformer, the difference
between the reaction velocity of the reforming reactions (mainly,
steam reforming reaction) in the reforming passages and the
reaction velocity of the combustion reactions in the combustion
passages is large, that is, the difference in the amount of
reaction per volume between the reforming passages and the
combustion passages is large, there has been a limit to the
improvement in the reforming efficiency of the system when the
configuration is adopted in which the reforming passages and
combustion passages are merely alternately formed in the stacking
direction as described above.
SUMMARY OF THE INVENTION
[0006] The present invention provides a heat exchange reformer unit
of which the efficiency of heat exchange between a heating section
and a reforming section is excellent. The present invention also
provides a heat exchange reformer unit and a reformer system, which
make it possible to improve reforming efficiency.
[0007] A heat exchange reformer unit according to a first aspect of
the present invention includes: a reforming section, in which
reforming catalyst for inducing reforming reactions is supported,
for producing reformats gas, which contains hydrogen, from supplied
reformation material through reforming reactions including
steam-reforming reaction; a heating section, which is disposed
adjacent to the reforming section with a separation wall interposed
between the heating section and the reforming section so as to
cause a gas flow in the same direction as that of a gas flow in the
reforming section, and in which oxidizing catalyst for catalytic
combustion is supported, for supplying, to the reforming section,
heat generated by catalytically burning supplied fuel; a
reformation material-introducing section, one end of which serves
as a supply port of the reformation material, and the other end of
which is integral with a reformation material inflow side of the
reforming section; and a fuel-introducing section, one end of which
serves as a supply port of the fuel, and the other end of which is
integral with a fuel inflow side of the heating section, for
introducing the fuel into the heating section in a flow direction
different from a flow direction of the reformation material in the
reformation material-introducing section.
[0008] In the heat exchange reformer unit according to the first
aspect, reforming reactions are caused (promoted) in the reforming
section by bringing supplied reformation material into contact with
the reforming catalyst with heat supplied from the heating section,
so that reformate gas that contains hydrogen is obtained. Reforming
reactions create a highly endothermic region near the end portion
on the upstream side (on the reformation material supply side) of
the region in which the reforming catalyst is supported. Combustion
reactions create a highly exothermic region near the end portion on
the upstream side (on the fuel supply side) of the region in which
the oxidizing catalyst is supported.
[0009] The direction in which the reformation material (or the
reformate gas) flows in the reforming section, and the direction in
which the fuel or fuel gas flows in the heating section are the
same. In other words, the heating section and the reforming section
constitute a parallel-flow heat exchange reformer unit.
Accordingly, it is possible to create the highly endothermic
region, which is created by the combustion reactions in the heating
section, and the highly exothermic region, which is created by the
reforming reactions in the reforming section, on the same side
(upstream side) of the regions, in which the catalysts are
supported, in the gas flow direction. Thus, it is possible to
locate the region in which a large amount of heat is generated,
close to the region in which endothermic demand is large (that is,
to match the endothermic distribution and the exothermic
distribution).
[0010] In this heat exchange reformer, the reformation
material-introducing section, which is integral with the upstream
side of the reforming section, and the fuel-introducing section,
which is integral with the upstream side of the heating section in
which the gas flow direction is parallel to that in the reforming
passage (that is, the gas inlet ports of the reforming section and
the heating section of, so to speak, the heat exchanger are
positioned at virtually the same position), are constructed so as
to cause gases to flow in directions different from each other. In
other words, the reformation material-introducing section and the
fuel-introducing section constitute a quasi cross-flow section.
Thus, it is possible to allow the supply port of the reformation
material and the supply port of the fuel to be open separately.
Accordingly, it is made possible to separately supply reformation
material and fuel to the same side of the reforming section and the
heating section, and it is possible to construct a parallel-flow
heat exchange reformer unit in which the region, in which a large
amount of heat is generated, is located near the region, in which
endothermic demand is large, as described above.
[0011] As described above, the heat exchange reformer unit
according to the first embodiment has excellent efficiency of heat
exchange between the heating section and the reforming section. In
addition, because heat is exchanged between the reformation
material flowing through the reformation material-introducing
section and the fuel flowing through the fuel-introducing section,
the stability (robustness) of operation is enhanced, and it is made
possible to realize stable operation against fluctuations
(variation in the temperature of the reformation material, for
example).
[0012] In the heat exchange reformer unit according to this aspect,
the entirety of the fuel-introducing section may be a region in
which no oxidizing catalyst is supported.
[0013] In the heat exchange reformer unit according to this aspect,
oxidizing catalyst is not supported in the fuel-introducing
section, and therefore, catalytic combustion does not occur in the
fuel-introducing section. Thus, the situation is prevented in which
heat generated by catalytic combustion is not used in the reforming
section and causes local high-temperature regions to occur. In
particular, even in the case of adopting configurations in which
reforming catalyst is supported in the reformation
material-introducing section, local high-temperature regions can
occur because the position of the highly endothermic region and the
position of the highly exothermic region are not matched when
oxidizing catalyst is supported in the fuel-introducing section,
which, together with the reformation material-introducing section,
forms a quasi cross-flow section described above. However, when
oxidizing catalyst is not supported in the fuel-introducing
section, occurrence of local high-temperature regions is
effectively prevented.
[0014] In the heat exchange reformer unit according to this aspect,
a plurality of the reforming sections and a plurality of the
heating sections may be provided, and may be stacked with at least
part of the plurality of the reforming sections being adjacent to
at least part of the plurality of the heating sections, the
reformation material-introducing section may be provided for each
of the reforming sections, and surface planes of the reformation
material supply ports may be substantially on the same plane, and
the fuel-introducing section may be provided for each of the
heating sections, and surface planes of the fuel supply ports may
be substantially on the same plane.
[0015] In the heat exchange reformer unit according to this aspect,
the plurality of the reforming sections and the plurality of the
heating sections are stacked, and at least part of the reforming
sections are adjacent to at least part of the heating sections. The
number of the heating sections provided may be equal to or less
than that of the reforming sections, and every heating section may
be adjacent to the reforming section on each side of the heating
section in the stacking direction. Because the reformation
material-introducing sections that are open on the same surface
plane are provided in the respective layers of the reforming
sections, and the fuel-introducing sections that are open on the
same surface plane are provided in the respective layers of the
reforming sections, it is possible to separately supply reformation
material and fuel to the same side of the reforming sections and
the heating sections. Thus, it is possible to construct a
parallel-flow heat exchange reformer unit, in which the region in
which a large amount of heat is generated is located close to the
region in which endothermic demand is large, with a multilayer
structure showing excellent heat exchange efficiency.
[0016] In the heat exchange reformer unit according to this aspect,
the heat exchange reformer unit may be constructed by stacking a
plurality of reforming section-forming plate members and a
plurality of heating section-forming plate members in a
predetermined pattern. Each of the reforming section-forming plate
members includes: a first flat-shaped plate portion; and a first
standing wall provided on the first flat-shaped plate portion in a
standing condition for guiding the reformation material in a
predetermined direction, wherein a first heat exchanging section
constituting the reforming section together with another plate
portion is formed of part of the first flat-shaped plate portion,
and wherein a reformation material guide section constituting the
reformation material-introducing section together with another
plate portion is formed of part of the first flat-shaped plate
portion and the first standing wall that is formed adjacent to a
reformation material supply-side of the first heat exchanging
section. Each of the heating section-forming plate members
includes: a second flat-shaped plate portion; and a second standing
wall provided on the second flat-shaped plate portion in a standing
condition for guiding the fuel in a direction intersecting the
predetermined direction, wherein a second heat exchanging section
constituting the heating section together with another plate
portion is formed of part of the second flat-shaped plate portion,
and wherein a fuel guide section constituting the fuel-introducing
section together with another plate portion is formed of part of
the second flat-shaped plate portion and the second standing wall
that is formed adjacent to a fuel supply-side of the second heat
exchanging section.
[0017] In the heat exchange reformer unit according to this aspect,
the reforming section-forming plate members and the heating
section-forming plate members are stacked in a predetermined
pattern, so that the reforming sections and the heating sections
are formed between the heat exchanging sections in the plate
portions, and the reformation material-introducing sections and the
fuel-introducing sections are formed between the reformation
material guide sections and the fuel guide sections in the plate
portions. Specifically, by stacking the reforming section-forming
plate members and the heating section-forming plate members in a
predetermined pattern, the reformation material-introducing
sections and the fuel-introducing sections are integrally formed on
the upstream side of the parallel-flow heat-exchanging sections,
wherein the reformation material-introducing sections and the
fuel-introducing sections have the reformation material supply
ports and the fuel supply ports, respectively, which are open
separately.
[0018] The heat exchange reformer unit according to this aspect may
further include: a reformation material manifold, defining a
collection space to which the reformation material supply ports of
the plurality of the reformation material-introducing sections are
open, for distributing the reformation material to the plurality of
the reformation material-introducing sections; and a fuel manifold,
defining a collection space to which the fuel supply ports of the
plurality of the fuel-introducing sections are open, for
distributing the fuel to the plurality of the fuel-introducing
sections.
[0019] In the heat exchange reformer unit according to this aspect,
the supply ports of the reformation material-introducing sections
for introducing reformation material into the reforming sections of
the respective layers are open to the reformation material
manifold, and the supply ports of the fuel-introducing sections for
introducing fuel into the heating sections of the respective layers
are open to the fuel manifold. Thus, it is possible to evenly
distribute reformation material from the reformation material
manifold to the reforming sections of the respective layers through
the reformation material-introducing sections of the respective
layers. Similarly, it is possible to evenly distribute fuel from
the fuel manifold to the heating sections of the respective layers
through the fuel-introducing sections of the respective layers. In
particular, by providing the fuel manifold with a mixer for mixing
fuel and combustion-supporting gas, it is made possible to supply
mixed gas, which is previously mixed immediately upstream of the
heating sections of the respective layers, to the heating sections
of the respective layers. In this case, occurrence of the regions
in which fuel concentration is locally high is prevented, and thus,
occurrence of local high-temperature regions in the heating
sections is prevented.
[0020] The heat exchange reformer unit according to this aspect may
further include: a reformate gas-discharging section, one end of
which serves as a discharge port of the reformate gas, and the
other end of which is integral with a reformate gas outflow side of
the reforming section; and a combustion exhaust gas-discharging
section, one end of which serves as a discharge port of combustion
exhaust gas of the heating section, and the other end of which is
integral with a combustion exhaust gas outflow side of the heating
section, for introducing the combustion exhaust gas to the
discharge port of the combustion exhaust gas in a flow direction
different from a flow direction of the reformate gas in the
reformate gas-discharging section.
[0021] In this heat exchange reformer according to this aspect, the
reformate gas-discharging section, which is integral with the
downstream side of the reforming section, and the combustion
exhaust gas-discharging section, which is integral with the
downstream side of the heating section in which the gas flow
direction is parallel to that in the reforming passage (that is,
the gas outlet ports of the reforming section and the heating
section of, so to speak, the heat exchanger are positioned at
virtually the same position), are constructed so as to cause gases
to flow in directions different from each other. In other words,
the reformate gas-discharging section and the combustion exhaust
gas-discharging section constitute a quasi cross-flow section.
Thus, it is possible to allow the discharge port of the reformate
gas and the discharge port of the combustion exhaust gas to be open
separately. Accordingly, it is made possible to separately
discharge reformate gas and combustion exhaust gas to the same side
of the reforming section and the heating section, and it is
possible to construct a parallel-flow heat exchange reformer unit
in which the region, in which a large amount of heat is generated,
is located near the region in which endothermic demand is large, as
described above.
[0022] In the configuration in which a plurality of reforming
sections and a plurality of heating sections are stacked so that at
least part of the reforming sections are adjacent to at least part
of the heating sections, the reformate gas-discharging sections may
be provided for the reforming sections of the respective layers,
and the combustion exhaust gas-discharging sections may be provided
for the heating sections of the respective layers. In particular,
in the case of a configuration in which the reforming
section-forming plate members and the heating section-forming plate
members are stacked in a predetermined pattern, the configuration
as described below may be adopted. Specifically, the reformate gas
guide section is formed in the plate portion of the reforming
section-forming plate member on the side of the heat-exchanging
section opposed to the reformation material guide section. On the
reformate gas guide section, the standing walls for guiding
reformate gas in another predetermined direction are provided in a
standing condition, and the reformate gas guide section constitutes
the reformate gas-discharging section together with another plate
portion. Meanwhile, the exhaust gas guide section is formed in the
plate portion of the heating section-forming plate member on the
side of the heat-exchanging section opposed to the fuel guide
section. On the exhaust gas guide section, the standing walls for
guiding combustion exhaust gas in a direction intersecting the
another predetermined direction in the reforming section-forming
plate member are provided in a standing condition, and the exhaust
gas guide section constitutes the combustion exhaust
gas-discharging section together with another plate portion. With
this configuration, by stacking the reforming section-forming plate
members and the heating section-forming plate members in a
predetermined pattern, it is possible to separately provide the
inlet port and the outlet port of the respective gas of a
parallel-flow heat exchanger.
[0023] A heat exchange reformer according to a second aspect of the
present invention includes: a plurality of reforming sections for
producing reformate gas, in which reforming catalyst for inducing
reforming reactions is supported; and a plurality of heating
sections, in which reforming catalyst for catalytic combustion is
supported, for supplying heat, which is generated by catalytically
burning supplied fuel, to the reforming sections, wherein the
number of the heating sections is less than the number of the
reforming sections.
[0024] In the heat exchange reformer unit according to this aspect,
reformate gas is obtained by bringing supplied reformation material
into contact with the reforming catalyst in the reforming section
with combustion heat supplied from the heating section to cause
(promote) reformation reactions. In the meantime, because the
reaction velocity of reforming reactions is lower than that of
combustion reactions, reforming reactions require a reaction space
(volume) larger than that of combustion reactions. In the heat
exchange reformer unit according to this aspect, the number of
layers of the reforming sections is greater than the number of
layers of the heating sections, the difference in the amount of
reaction per volume between the reforming passages and the
combustion passages is compensated by the difference in the number
of layers thereof (the volume of reaction space). That is, the
amount of reaction is set according to the reaction field, and it
is possible to increase the amount of reformate gas produced
relative to the amount of reformation material supplied, or to the
volume of the heat exchange reformer unit.
[0025] As described above, with the heat exchange reformer unit
according to this aspect, it is possible to increase reforming
efficiency. The reforming section may be a reaction section for
producing reformate gas that contains hydrogen from supplied
reformation material through reforming reactions including the
steam-reforming reaction, for example.
[0026] A heat exchange reformer according to a third aspect of the
present invention includes: a plurality of reforming sections for
producing reformate gas, in which reforming catalyst for inducing
reforming reactions is supported; and a plurality of heating
sections, in which reforming catalyst for catalytic combustion is
supported, for supplying heat, which is generated by catalytically
burning supplied fuel, to the reforming reactions, wherein the
plurality of the reforming sections and the plurality of the
heating sections are stacked so that the surface area of the region
in which the reforming catalyst is supported is greater than the
surface area of the region in which the oxidizing catalyst is
supported.
[0027] In the heat exchange reformer unit according to this aspect,
reformate gas is obtained by bringing supplied reformation material
into contact with the reforming catalyst in the reforming section
with combustion heat supplied from the heating section to cause
(promote) reformation reactions. In the heat exchange reformer unit
according to this aspect, in the area in which heat is exchanged
between the reforming sections and the heating sections, the
surface area of the region in which the reforming catalyst is
supported is greater than the surface area of the region in which
the oxidizing catalyst is supported. For this reason, the amount of
reforming reaction relative to the amount of combustion reaction is
increased, and therefore, the difference in the amount of reaction
between the reforming sections and the combustion sections is
reduced (the difference in the amount of reaction per volume is
compensated). That is, the amount of reaction is set according to
the reaction field, and it is possible to increase the amount of
reformats gas produced relative to the amount of reformation
material supplied, or to the volume of the heat exchange reformer
unit.
[0028] As described above, with the heat exchange reformer unit
according to this aspect, it is possible to increase reforming
efficiency. The reforming section may be a reaction section for
producing reformate gas that contains hydrogen from supplied
reformation material through reforming reactions including the
steam-reforming reaction, for example.
[0029] A heat exchange reformer according to a fourth aspect of the
present invention includes: a plurality of reforming sections for
producing reformate gas, in which reforming catalyst for inducing
reforming reactions is supported; and a plurality of heating
sections, in which reforming catalyst for catalytic combustion is
supported, for supplying heat, which is generated by catalytically
burning supplied fuel, to the reforming reactions, wherein the
plurality of the reforming sections and the plurality of the
heating sections are stacked so that the amount of the reforming
catalyst supported is greater than the amount of the oxidizing
catalyst supported.
[0030] In the heat exchange reformer unit according to this aspect,
reformate gas is obtained by bringing supplied reformation material
into contact with the reforming catalyst in the reforming section
with combustion heat supplied from the heating section to cause
(promote) reformation reactions. In the heat exchange reformer unit
according to this aspect, in the area in which heat is exchanged
between the reforming sections and the heating sections, the amount
of reforming catalyst supported is greater than the amount of
oxidizing catalyst supported. For this reason, the amount of
reforming reaction relative to the amount of combustion reaction is
increased, and therefore, the difference in the amount of reaction
between the reforming sections and the combustion sections is
reduced (the difference in the amount of reaction per volume is
compensated). That is, the amount of reaction is set according to
the reaction field, and it is possible to increase the amount of
reformate gas produced relative to the amount of reformation
material supplied, or to the volume of the heat exchange reformer
unit.
[0031] As described above, with the heat exchange reformer unit
according to this aspect, it is possible to increase reforming
efficiency. The reforming section may be a reaction section for
producing reformats gas that contains hydrogen from supplied
reformation material through reforming reactions including the
steam-reforming reaction, for example.
[0032] A heat exchange reformer according to a fifth aspect of the
present invention includes: a plurality of reforming sections for
producing reformate gas, in which reforming catalyst for inducing
reforming reactions is supported; and a plurality of heating
sections, in which reforming catalyst for catalytic combustion is
supported, for supplying heat, which is generated by catalytically
burning supplied fuel, to the reforming reactions, wherein the
plurality of the reforming sections and the plurality of the
heating sections are stacked so that the total volume of the
plurality of the reforming sections is greater than the total
volume of the plurality of heating sections.
[0033] In the heat exchange reformer unit according to this aspect,
reformate gas is obtained by bringing supplied reformation material
into contact with the reforming catalyst in the reforming section
with combustion heat supplied from the heating section to cause
(promote) reformation reactions. In the meantime, because the
reaction velocity of reforming reactions is lower than that of
combustion reactions, reforming reactions require a reaction space
(volume) larger than that of combustion reactions. In the heat
exchange reformer unit according to this aspect, in the area in
which heat is exchanged between the reforming sections and the
heating sections, the total volume of the plurality of the
reforming sections (volume, that is, passage cross
section.times.passage length.times.number of layers) is greater
than the total volume of the plurality of the combustion sections.
For this reason, the difference in the amount of reaction per
volume between the reforming passages and the combustion passages
is compensated by the difference in the volume of the respective
reaction spaces (volume ratio). That is, the amount of reaction is
set according to the reaction field, and it is possible to increase
the amount of reformate gas produced relative to the amount of
reformation material supplied, or to the volume of the heat
exchange reformer unit.
[0034] As described above, with the heat exchange reformer unit
according to this aspect, it is possible to increase reforming
efficiency. The reforming section may be a reaction section for
producing reformats gas that contains hydrogen from supplied
reformation material through reforming reactions including the
steam-reforming reaction, for example.
[0035] In the heat exchange reformer unit according to this aspect,
the heat exchange reformer unit may include a part in which two
layers of the reforming sections are stacked per one layer of the
heating section.
[0036] The heat exchange reformer unit according to this aspect
includes a part in which the reforming sections and the heating
sections are stacked so that the units are stacked in each of which
two layers of the reforming sections are disposed on the same side
of one layer of the heating section, or so that the units are
stacked in each of which one layer of the heating section is
sandwiched between a pair of layers of the reforming sections, for
example. In such a part, two layers of the reforming sections are
disposed between a pair of the heating sections. Specifically, in
the part in which two layers of the reforming sections are stacked
per one layer of the heating section, at least one side of each
reforming section is adjacent to a heating section. In this way, it
is possible to increase the volume of the reforming sections (the
catalyst-supporting region surface area, or the amount of catalyst
supported) with the heat transport distance between the heating
sections and the reforming sections kept short as compared to that
of the configuration in which the heating sections and the
reforming sections are alternately stacked. For example, while the
ratio of the volume of the reforming sections to the overall volume
of the reformer unit is about 50% in the configuration in which the
heating sections and the reforming sections are alternately
stacked, it is possible to increase the ratio of the volume of the
reforming sections to the overall volume of the reformer unit to
about 67% in the above configuration.
[0037] In the heat exchange reformer unit according to this aspect,
the heat exchange reformer unit may include a part in which three
layers of the reforming sections are stacked per one layer of the
heating section.
[0038] The heat exchange reformer unit according to this aspect
includes a part in which the reforming sections and the heating
sections are stacked so that the units are stacked in each of which
three layers of the reforming sections are disposed on the same
side of one layer of the heating section, for example. In such a
part, three layers of the reforming sections are disposed between a
pair of the heating sections. In this way, while the ratio of the
volume of the reforming sections to the overall volume of the
reformer unit is about 50% in the configuration in which the
heating sections and the reforming sections are alternately
stacked, for example, it is possible to increase the ratio of the
volume of the reforming sections to the overall volume of the
reformer unit to about 75% in the above configuration. It has been
confirmed that, in this configuration, while a reforming section is
formed that is not adjacent to any heating sections (the heat
transport distance is long), the effect caused by the increase in
the reaction space surpasses the effect caused by the increase in
the heat transport distance under the operating conditions in which
the operating temperature is low, for example.
[0039] In the heat exchange reformer unit according to this aspect,
the heat exchange reformer unit may include a part in which four or
more layers of the reforming sections are stacked per one layer of
the heating section.
[0040] The heat exchange reformer unit according to this aspect
includes a part in which the reforming sections and the heating
sections are stacked so that the units are stacked in each of which
four layers of the reforming sections are disposed on the same side
of one layer of the heating section, for example. In such a part,
four layers of the reforming sections are disposed between a pair
of the heating sections. In this way, while the ratio of the volume
of the reforming sections to the overall volume of the reformer
unit is about 50% in the configuration in which the heating
sections and the reforming sections are alternately stacked, for
example, it is possible to increase the ratio of the volume of the
reforming sections to the overall volume of the reformer unit to
about 80% or more in the above configuration. It has been confirmed
that, in this configuration, while a reforming section is formed
that is not adjacent to any heating sections (the heat transport
distance is long), the effect caused by the increase in the
reaction space surpasses the effect caused by the increase in the
heat transport distance under the operating conditions in which the
operating temperature is low, for example.
[0041] The heat exchange reformer unit according to this aspect may
further include a heat transfer-promoting portion for promoting
heat transfer from the heating section to the adjacent reforming
section.
[0042] In the heat exchange reformer unit according to the above
aspect, thermal resistance between the heating sections and the
reforming sections is reduced by the heat transfer-promoting
portions, whereby the heat transport from the heating section to
the reforming section is promoted. Thus, even in the case of the
configuration in which the heat transport distance from part of the
reforming sections is long (the configuration in which heat
transfer-controlled effect is feared), such as in the case of the
configuration in which three reforming sections per heating section
are provided or four or more reforming sections per heating section
are provided, for example, it is possible to efficiently supply
heat to the reforming sections to which the heat transport distance
is long. That is, it is possible to broaden the operating
conditions (the range thereof) in which it is possible to enhance
the reforming efficiency using the configuration in which three
reforming sections per heating section are provided or four or more
reforming sections per heating section are provided. As the heat
transfer-promoting portion, a connecting wall or the like
connecting between the separation walls each separating the
reforming section and the heating section may be used, for
example.
[0043] A reformer system according to a sixth aspect of the present
invention includes: the heat exchange reformer unit according to
the above aspect; and a water supply system for supplying water to
the reforming section of the heat exchange reformer unit.
[0044] In the reformer system according to this aspect, the water
supplied to the reforming section through the water supply system
reacts with the reformation material in the reforming section, and
reforms the reformation material into reformate gas that contains
hydrogen. Specifically, reforming reactions including the
steam-reforming reaction, which is endothermic reaction, occur in
the reforming sections, and the heat required to cause the
steam-reforming reaction is supplied from the heating sections to
the reforming sections. Because the reformer system includes the
heat exchange reformer unit according to the above aspect, the
difference in the amount of reaction per volume between the
reforming passages (reforming sections) and the combustion passages
(heating sections) is compensated, and the reformer system
increases the amount of reformate gas produced relative to the
amount of reformation material supplied, or to the volume of the
heat exchange reformer unit, despite the configuration in which
steam-reforming reaction is caused that has reaction velocities
lower than those of combustion reactions.
[0045] The heat exchange reformer unit and the reformer system
according to the above aspects of the present invention have
excellent efficiency of heat exchange between the heating sections
and the reforming sections, and exhibit the advantageous effect
that the reforming efficiency is enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The foregoing and further objects, features and advantages
of the invention will become apparent from the following
description of preferred embodiments with reference to the
accompanying drawings, wherein like numerals are used to represent
like elements and wherein:
[0047] FIG. 1 is a schematic system flow diagram of a fuel cell
system in which a heat exchange reformer unit according to any one
of first to sixth embodiments of the present invention is used;
[0048] FIG. 2 is an exploded perspective view showing a main part
of the heat exchange reformer unit according to the first
embodiment of the present invention;
[0049] FIG. 3 is a perspective view of the heat exchange reformer
unit according to the first embodiment of the present
invention;
[0050] FIG. 4 is an exploded perspective view showing a
catalyst-supporting region of the heat exchange reformer unit
according to the first embodiment of the present invention;
[0051] FIGS. 5A to 5C are diagrams showing a process in which
catalyst is supported, in the heat exchange reformer unit according
to the first embodiment of the present invention, wherein FIG. 5A
is a schematic diagram showing a state in which a catalyst carrier
is flowing into the heat exchange reformer unit, FIG. 5B is a
schematic diagram showing a state in which the inflow of the
catalyst carrier is stopped, and FIG. 5C is a schematic diagram
showing a state in which the catalyst is introduced;
[0052] FIG. 6 is a diagram showing a temperature distribution in a
combustion passage of the heat exchange reformer unit according to
the first embodiment of the present invention;
[0053] FIGS. 7A to 7C are schematic diagrams showing examples that
are defective in supporting the catalyst;
[0054] FIGS. 8A and 8B are diagrams showing the heat exchange
reformer unit according to the second embodiment of the present
invention, wherein FIG. 8A is a front view, and FIG. 8B is a
partially enlarged front view;
[0055] FIG. 9 is an exploded perspective view showing a main part
of the heat exchange reformer unit according to the second
embodiment of the present invention;
[0056] FIG. 10 is a perspective view showing an external appearance
of the heat exchange reformer unit according to the second
embodiment of the present invention;
[0057] FIG. 11 is a diagram schematically showing the reaction
field of reforming reactions and the reaction field of combustion
reactions in the heat exchange reformer unit according to the
second embodiment of the present invention;
[0058] FIG. 12 is a graph showing the ratio of the volume of the
reforming passages to the volume of a multilayer core unit
constituting the heat exchange reformer unit according to any one
of the embodiments of the present invention;
[0059] FIG. 13 is a graph showing the relation between the area of
the region in which oxidizing catalyst is supported and the area of
the region in which reforming catalyst is supported in the
multilayer core unit constituting the heat exchange reformer unit
according to any one of the embodiments of the present
invention;
[0060] FIG. 14 is a diagram showing actually measured values of the
conversion ratio of the reformation material versus the ratio of
the volume of the reforming passages to the volume of the
multilayer core unit of the heat exchange reformer unit according
to any one of the embodiments of the present invention;
[0061] FIGS. 15A and 15B are diagrams showing the heat exchange
reformer unit according to the third embodiment of the present
invention, wherein FIG. 15A is a front view, and FIG. 15B is a
partially enlarged front view;
[0062] FIGS. 16A and 16B are diagrams showing the heat exchange
reformer unit according to the fourth embodiment of the present
invention, wherein FIG. 16A is a front view, and FIG. 16B is a plan
view;
[0063] FIG. 17 is a schematic diagram in which the multilayer core
unit constituting the heat exchange reformer unit according to the
fourth embodiment of the present invention is modeled as a heat
transfer fin unit;
[0064] FIG. 18 is a graph showing fin efficiency of the multilayer
core unit of the heat exchange reformer unit according to any one
of embodiments of the present invention;
[0065] FIGS. 19A and 19B are diagrams showing the heat exchange
reformer unit according to the fifth embodiment of the present
invention, wherein FIG. 19A is a front view, and FIG. 19B is a plan
view;
[0066] FIG. 20 is a front view showing the heat exchange reformer
unit according to the sixth embodiment of the present
invention;
[0067] FIGS. 21A and 21B are diagrams showing the heat exchange
reformer unit according to the seventh embodiment of the present
invention, wherein FIG. 21A is a front view, and FIG. 21B is a
partially enlarged front view; and
[0068] FIGS. 22A and 22B are diagrams showing the heat exchange
reformer unit according to a comparative example for comparison
with the embodiments of the present invention, wherein FIG. 22A is
a front view, and FIG. 22B is a partially enlarged front view;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0069] A heat exchange reformer unit 10 according to a first
embodiment of the present invention will be described with
reference to FIGS. 1 to 6. First, the overall system configuration
of a fuel cell system 11, in which the heat exchange reformer unit
10 is used, will be described, and then the structural details of
the heat exchange reformer unit 10 will be described.
[0070] FIG. 1 shows a system configuration diagram (process flow
sheet) of the fuel cell system 11. As shown in FIG. 1, the fuel
cell system 11 is constructed using, as main components, a fuel
cell 12 that uses hydrogen to generate electricity, and the heat
exchange reformer unit (reformer) 10 for producing reformate gas
that contains hydrogen to be supplied to the fuel cell 12.
[0071] The fuel cell 12 is constructed with electrolyte (not shown)
interposed between an anode electrode (fuel electrode) 14 and a
cathode electrode (air electrode) 16, and is configured so as to
generate electricity mainly by electrochemically reacting the
hydrogen that is supplied to the anode electrode 14, and the oxygen
that is supplied to the cathode electrode 16. Although various
types of fuel cells may be used as the fuel cell 12, in this
embodiment, a fuel cell having proton conductive electrolyte (such
as a solid polymer fuel cell and a hydrogen membrane fuel cell) is
used, which is operated at medium temperatures (about 300 to
700.degree. C.), and in which water is produced at the cathode
electrode 16 as electricity is generated.
[0072] As shown in FIG. 1, the heat exchange reformer unit 10
includes: a reforming passage 18, which constitutes a reforming
section for producing the reformate gas, which contains hydrogen,
to be supplied to the anode electrode 14 of the fuel cell 12; and a
combustion passage 20, which constitutes a heating section for
supplying heat that is used in the reforming passage 18 to cause
reforming reactions. The reforming passage 18 supports reforming
catalyst 22, so that reformate gas that contains hydrogen is
produced (reforming reactions are caused) by catalytically reacting
hydrocarbon gas (such as gasoline, methanol and natural gas) and
reforming gas (steam), which are supplied.
[0073] The reforming reactions in the reforming passage 18 includes
reactions including the steam-reforming reaction expressed by the
equation (1), as shown by the following equations (1) to (4).
Accordingly, the reformate gas obtained through the reforming
process contains combustible gas, such as hydrogen (H.sub.2),
carbon monoxide (CO), methane (CH.sub.4), decomposed hydrocarbon
and unreacted hydrocarbon material (C.sub.xH.sub.y), and
incombustible gas, such as carbon dioxide (CO.sub.2) and water
(H.sub.2O).
C.sub.nH.sub.m+nH.sub.2O?nCO+(n+m/2)H.sub.2 (1)
C.sub.nH.sub.m+n/2O.sub.2?nCO+m/2H.sub.2 (2)
CO+H.sub.2OCO.sub.2+H.sub.2 (3)
CO+3H.sub.2?CH.sub.4+H.sub.2O (4)
The steam-reforming reaction expressed by the equation (1), which
is the principal reaction among these reforming reactions, is
endothermic reaction, and, in the reforming passage 18, operation
is performed at temperatures equal to or higher than a
predetermined temperature to supply reformate gas to the fuel cell
12 that is operated at medium or high temperatures as described
above. The combustion passage 20 is configured so as to supply heat
used to maintain the reforming reactions and the working
temperature in the reforming passage 18. The combustion passage 20
supports oxidizing catalyst 24, and is disposed adjacent to the
reforming passage 18, so that the combustion passage 20 is
configured so as to bring the supplied fuel and oxygen into contact
with the oxidizing catalyst 24 to cause catalytic combustion. The
partial oxidation reaction expressed by the equation (2) is
exothermic reaction. The heat generated by the partial oxidation
reaction is used in the steam-reforming reaction together with the
heat supplied from the combustion passage 20.
[0074] The heat exchange reformer unit 10 is designed to supply the
combustion heat obtained by catalytically burning fuel in the
combustion passage 20 to the reforming passage 18 through a plate
portion 52 described later. Thus, the heat exchange reformer unit
10 is configured so as to be able to directly supply heat to the
reforming passage 18 without converting the heat into temperature
as in the case of the configuration in which the reforming passage
18 is heated using heating medium (fluid), such as combustion
gas.
[0075] The fuel cell system 11 includes a material pump 26 for
supplying hydrocarbon material to the reforming passage 18. The
discharge port of the material pump 26 is connected to a material
inlet port 18A of the reforming passage 18 through a material
supply line 28. The hydrocarbon material includes a very small
amount of sulfur ingredients (sulfur compounds), which do not
contribute to the reforming reactions described above. The
hydrocarbon material is supplied to the reforming passage 18 in a
gas phase or in an atomized form by a vaporizing device or the like
(not shown), such as a vaporizer and an injector.
[0076] A reformate gas outlet 18B of the reforming passage 18 is
connected to the upstream end of a reformate gas supply line 30,
the downstream end of which is connected to a fuel inlet 14A of the
anode electrode 14. Thus, the reformate gas produced in the
reforming passage 18 is supplied to the anode electrode 14 of the
fuel cell 12. The upstream end of an anode off-gas line 32 is
connected to an off-gas outlet 14B of the anode electrode 14. The
downstream end of the anode off-gas line 32 is connected to a fuel
inlet 33A of a gas mixer 33. The gas mixer 33 substantially
homogeneously mixes the anode off-gas and the coolant off-gas
supplied through a combustion-supporting gas supply line 46
described later. A mixed gas outlet 33B of the gas mixer 33 is
connected to a fuel (mixed gas) inlet 20A of the fuel passage
20.
[0077] In this way, the fuel cell system 11 is designed so that
hydrogen in the reformate gas produced in the reforming passage 18
is used in the fuel cell 12, the remaining components, other than
the used hydrogen, are introduced into the combustion passage 20 as
an anode off-gas, and the combustible components therein (H.sub.2,
CO, HC and CH.sub.4) are used as fuel in the combustion passage 20.
An exhaust gas line 34 for discharging combustion exhaust gas out
of the system is connected to an exhaust gas outlet 20B.
[0078] The fuel cell system 11 includes a cathode air pump 36 for
supplying cathode air to the cathode electrode 16. Connected to the
discharge port of the cathode air pump 36 is the upstream end of a
cathode air supply line 38, the downstream end of which is
connected to an air inlet 16A of the cathode electrode 16. The
upstream end of a steam supply line 40 is connected to an off-gas
outlet 16B of the cathode electrode 16, and the downstream end of
the steam supply line 40 is connected to a steam inlet 18C of the
reforming passage 18. Thus, the cathode off-gas that contains steam
produced by the cathode electrode 16 and oxygen that is not used on
the cathode electrode 16 are supplied to the reforming passage 18.
The steam in the cathode off-gas is used in the steam-reforming
reaction expressed by the equation (1), and oxygen is used in the
partial oxidation reaction expressed by the equation (2). The heat
exchange reformer unit 10 according to the first embodiment is
configured so as to be operated under particular conditions in
which the O/C ratio that is the ratio of the amount of supplied
oxygen to the amount of carbon in the hydrocarbon material is set
to a particular ratio by supplying cathode off-gas that contains
oxygen to the reforming passage 18.
[0079] The fuel cell system 11 includes a cooling air pump 42 for
supplying cooling air to the fuel cell 12. The discharge port of
the cooling air pump 42 is connected to the upstream end of a
cooling air supply line 44, the downstream end of which is
connected to an inlet 12A of the coolant passage (not shown) of the
fuel cell 12. An outlet 12B of the coolant passage is connected to
the upstream end of a combustion-supporting gas supply line 46. The
combustion-supporting gas supply line 46 is connected to a
combustion-supporting gas inlet 33C of the gas mixer 33 so as to
supply coolant off-gas that contains oxygen as
combustion-supporting gas to the gas mixer 33. Thus, in the
combustion passage 20, the mixed gas that is obtained by mixing the
anode off-gas supplied through the anode off-gas line 32 and the
coolant off-gas supplied through the combustion-supporting gas
supply line 46 in the gas mixer 33, is brought into contact with
the oxidizing catalyst 24 that the combustion passage 20 has
therein, thereby causing catalytic combustion. It should be noted
that, instead of the configuration in which the gas mixer 33 is
provided, a configuration may be adopted in which the downstream
end of the anode off-gas line 32 and the downstream end of the
combustion-supporting gas supply line 46 are individually connected
to the combustion passage 20, for example.
[0080] In the above configuration, the fuel cell 12 (cathode
electrode 16) and the steam supply line 40 may be regarded as the
water supply device of the present invention, and the fuel cell
system 11 (more specifically, the part of the fuel cell system 11,
which includes the heat exchange reformer unit 10, the cathode
electrode 16, and the steam supply line 40) may be regarded as the
reformer system of the present invention.
[0081] With regard to the fuel cell system 11, a configuration may
be adopted in which the steam supply line 40 is provided with a
separation membrane (a porous separation membrane made of polyimide
and ceramic, for example) that selectively allows permeation of
only the steam in the cathode off-gas, or in which the steam used
in reforming is introduced from the outside of the system, so that
oxygen is not supplied to the reforming passage 18, or that the
ratio (O/C ratio) of the amount of supplied oxygen to the amount of
carbon in the hydrocarbon material is small. In the case of such
configurations, the main reaction of the reforming reactions in the
heat exchange reformer unit 10 is the steam-reforming reaction, and
therefore, the partial oxidation reaction is not caused, or the
amount of heat generated by the partial oxidation reaction becomes
very small.
[0082] FIG. 2 shows a multilayer core unit 65 of the heat exchange
reformer unit 10 in an exploded perspective view. As shown in FIG.
2, in the heat exchange reformer unit 10, the reforming passages 18
constituting the reforming sections and the combustion passages 20
constituting the heating sections are formed in the form of
separate gas passages between the unit plate members 50 and 51,
which are provided as a plurality of reforming section-forming
plate members and a plurality of heating section-forming plate
members, which are stacked, wherein the reforming passages 18 and
the combustion passages 20 are separated by the plate portions 52
as separation walls, which may be regarded as flat-shaped plate
portions of the unit plate members 50 and 51. In this embodiment,
the reforming passages 18 and the combustion passages 20 are
alternately stacked in the stacking direction (the thickness
direction of the plate portion 52). The reforming passage 18 and
the combustion passage 20 are adjacent to each other with the plate
portion 52 interposed therebetween. Specific description will be
given below.
[0083] The unit plate member 50 includes the plate portion 52
formed in a flat shape. The plate portion 52 is formed by
integrally providing, at both ends in the longitudinal direction of
a parallel flow portion 52 constituting a heat exchanging section
formed in a rectangular shape, flow direction-changing sections 52B
and 52C, when viewed from above. In this embodiment, the flow
direction-changing sections 52B and 52C are formed in a triangular
shape such that the bases thereof are made to coincide with the
corresponding short sides of the parallel flow portion 52A (with a
rectangular shape). Accordingly, the plate portion 52 as a whole is
formed in a substantially hexagonal shape. Each unit plate member
50 includes outer walls 54, which are provided in a standing
condition at edges of the plate portion 52 on the side thereof on
which the reforming passages 18 are formed.
[0084] The outer walls 54 are provided in a standing condition all
around the plate portion 52 except one side portion of each of the
direction-changing sections 52B and 52C, so that the outer walls 54
function as spacers that define the reforming passages 18 between
the stacked unit plate members 50 and 51, and also function as
outer walls that prevent the outflow of gas from the reforming
passages 18, and, at the same time, create a gas inlet 50A on the
flow-direction changing section 52B-side, and a gas outlet 50B on
the flow-direction changing section 52C-side. The gas inlet 50A and
the gas outlet 50B are formed symmetrically with respect to the
centroid of the plate portion 52, and the openings thereof are
oriented in the directions indicated by the arrows C1 and C2 beside
the flow-direction changing sections 52B and 52C, respectively,
which are opposite to the direction of the parallel flow portion
52A, which extends along the longitudinal direction of the outer
walls 54.
[0085] A plurality of standing walls (partition walls) 56 that
divide the reforming passage 18 into a plurality of parallel
passages are provided in a standing condition on the reforming
passage 18-formed-side of the plate portion 52 of the unit plate
members 50. The standing walls 56 are made substantially parallel
with the outer walls 54 from the gas inlet 50A to the gas outlet
50B, and are configured so as to divide the reforming passage 18
into a plurality of divided passages (microchannels) 58. Each
divided passage 58 is formed in a crank-like shape such that the
length of the passages from the gas inlet 50A to the gas outlet 50B
is substantially the same owing to the symmetrical arrangement of
the gas inlet 50A and the gas outlet 50B described above.
[0086] The part of the divided passages 58 in the parallel flow
portion 52A that are separated by partition wall portions 56A of
the standing walls 56 lying along the longitudinal direction of the
parallel flow portions 52A, serve as heat-exchanging passages 58A.
Meanwhile, the part of the divided passages 58 between which inlet
guide walls 56B are provided on the flow-direction changing section
52B in a standing condition, serve as reformation material guide
passages 58B constituting a reformation material guide section. The
inlet guide walls 56B are part of the standing walls 56, and lie
along the direction indicated by the arrow C1. In addition, the
part of the divided passages 58 between which outlet guide walls
56C are provided on the flow-direction changing section 52C in a
standing condition, serve as reformate gas guide passages 58C
constituting a reformate gas guide section. The outlet guide walls
56C are part of the standing walls 56, and lie along the direction
indicated by the arrow C2.
[0087] The unit plate member 51 includes a plate portion 52 that
has the same shape as that of the plate portion 52 constituting the
unit plate member 50, and includes outer walls 60, which are
provided in a standing condition at the periphery of the plate
portion 52 on the side thereof on which the combustion passages 20
are formed. The outer walls 60 are provided in a standing condition
all around the plate portion 52 except one side portion of each of
the direction-changing sections 52B and 52C, so that the outer
walls 60 function as spacers that form the combustion passages 20
between the stacked unit plate members 50 and 51, and also function
as outer walls that prevent the outflow of gas from the combustion
passages 20, and so that the outer walls 60 form a gas inlet 51A on
the flow-direction changing section 52B-side, and a gas outlet 51B
on the flow-direction changing section 52C-side.
[0088] The gas inlet 51A is formed on the same side of a parallel
flow portion 52A in the longitudinal direction as the gas inlet 50A
of the unit plate member 50 (that is, on the side indicated by the
arrow A in FIG. 2) so as to be open toward the direction indicated
by the arrow D1, which is different from the direction indicated by
the arrow C1 (that is, which is symmetric with respect to the
longitudinal axis of the parallel flow portion 52A), toward which
the gas inlet 50A is open. Meanwhile, the gas outlet 5B is formed
on the same side of a parallel flow portion 52A in the longitudinal
direction as the gas outlet 50B of the unit plate member 50 (that
is, on the side indicated by the arrow B in FIG. 2) so as to be
open toward the direction indicated by the arrow D2, which is
different from the direction indicated by the arrow C2 (that is,
which is symmetric with respect to the longitudinal axis of the
parallel flow portion 52A), toward which the gas outlet SOB is
open.
[0089] A plurality of standing walls (partition walls) 62 that
divide the combustion passage 20 into a plurality of parallel
passages are provided in a standing condition on the combustion
passage 20-formed-side of the plate portion 52 of the unit plate
members 51. The standing walls 62 are made substantially parallel
with the outer walls 60 from the gas inlet 51A to the gas outlet
51B, and are configured so as to divide the combustion passage 20
into a plurality of divided passages (microchannels) 64. Each
divided passage 64 is formed in a crank-like shape such that the
length of the passages from the gas inlet 51A to the gas outlet 51B
is substantially the same owing to the symmetrical arrangement of
the gas inlet 51A and the gas outlet 51B described above.
[0090] The part of the divided passages 64 in the parallel flow
portion 52A that are separated by partition wall portions 62A of
the standing walls 62 lying along the longitudinal direction of the
parallel flow portions 52A, serve as heat-exchanging passages 64A.
Meanwhile, the part of the divided passages 64 between which inlet
guide walls 62B are provided on the flow-direction changing section
52B in a standing condition, serve as mixed gas guide passages 64B
constituting a fuel guide section. The inlet guide walls 62B are
part of the standing walls 62, and lie along the direction
indicated by the arrow D1. In addition, the part of the divided
passages 64 between which outlet guide walls 62C are provided on
the flow-direction changing section 52C in a standing condition,
serve as combustion exhaust gas guide passages 64C constituting a
combustion exhaust gas guide section. The outlet guide walls 62C
are part of the standing walls 62, and lie along the direction
indicated by the arrow D2.
[0091] In the heat exchange reformer unit 10 described above, the
gas inlets 50A and 51A are positioned on the same side (that is, on
the side indicated by the arrow A) of the parallel flow portion 52A
(the heat-exchanging passages 58A and 64A), and the gas outlets SOB
and SIB are positioned on the same side (that is, on the side
indicated by the arrow B) of the parallel flow portion 52A as
described above, so that the directions in which gas flows in the
heat-exchanging passages 58A and 64A on the respective layers are
set to the same direction (the direction indicated by the arrow
F).
[0092] In each of the unit plate members 50 and 51 described above,
the portions (the plate portion 52, the outer walls 54 and the
standing walls 56; or the plate portion 52, the outer walls 60 and
the standing walls 62) are integrally formed of metallic materials,
such as stainless steel, or solid (not porous) ceramics, for
example. The plurality of the unit plate members 50 and the
plurality of the unit plate members 51 constitute the multilayer
core unit 65 of the heat exchange reformer unit 10, wherein the
plate members 52 and the outer walls 54 and 60 (the standing walls
56 and 62) are airtightly joined by brazing using brazing filler or
by diffusion bonding, for example. As shown in FIG. 3, in the heat
exchange reformer unit 10, in this embodiment, a flat-shaped plate
portion 52 (cover) on which the outer walls 54 or the like are not
provided in a standing condition is placed on the top of the heat
exchange reformer unit 10 so as to close the reforming passage
18.
[0093] As shown in FIG. 3, a reformation inlet manifold 66 that
defines a collection space to which the gas inlets 50A of the
respective layers are open is connected to the multilayer core unit
65. In addition, a reformation outlet manifold 68 that defines a
collection space to which the gas outlets 50B of the respective
layers are open is connected to the multilayer core unit 65.
Moreover, a combustion inlet manifold 70 that defines a collection
space to which the gas inlets 51A of the respective layers are open
is connected to the multilayer core unit 65. Furthermore, a
combustion outlet manifold 72 that defines a collection space to
which the gas outlets 51B of the respective layers are open is
connected to the multilayer core unit 65. Bach of the manifolds 66,
68, 70 and 72 is formed in a rectangular tube shape, and one open
end thereof is joined to the end portions of the top and bottom
plate portions 52, and the end portions of the outer walls 54 and
60 of the respective layers by brazing, for example.
[0094] The material inlet 18A and the steam inlet 18C for
introducing reformation material (hydrocarbon) and steam (cathode
off-gas), respectively, are provided in the reformation inlet
manifold 66, and the reformats gas outlet 18B for discharging
reformate gas is provided in the reformation outlet manifold 68.
Meanwhile, the fuel inlet 20A for introducing mixed gas from the
gas mixer 33 is provided in the combustion inlet manifold 70, and
the exhaust gas outlet 20B for discharging combustion exhaust gas
is provided in the combustion outlet manifold 72.
[0095] In the heat exchange reformer unit 10 (multilayer core unit
65) described above, the reforming catalyst 22 is supported on the
inner surface of the divided passages 58 on the unit plate member
50, and the oxidizing catalyst 24 is supported on the inner surface
of the divided passages 64 on the unit plate member 51. As shown in
FIG. 4, which is an exploded plan view in which the illustration of
the standing walls 56 and 62 is omitted, the reforming catalyst 22
is supported in the divided passages 58 (reforming passage 18) in a
predetermined region thereof that does not include part of the
divided passages 58 on the gas inlet 50A-side, and the oxidizing
catalyst 24 is supported in the divided passages 58 (combustion
passage 20) in a predetermined region thereof that does not include
part of the divided passages 64 on the gas inlet 51A-side.
[0096] More specifically, as shown in FIG. 4, with regard to the
reforming catalyst 22, an upstream-side supporting region end 22A
that is the end on the upstream side (that is, on the side
indicated by the arrow A) in the gas flow direction in which the
reformation material is supplied, substantially coincides with the
border between the heat-exchanging passages 58A (parallel flow
sections 52A) and the reformation material guide passages 58B (flow
direction-changing sections 521) of the divided passages 58. With
regard to the oxidizing catalyst 24, an upstream-side supporting
region end 24A that is the end on the upstream side (that is, on
the side indicated by the arrow A) in the gas flow direction in
which the fuel is supplied, substantially coincides with the border
between the heat-exchanging passages 64A (parallel flow sections
52A) and the mixed gas guide passages 64B (flow-direction changing
sections 52B) of the divided passages 64. It should be noted that
the upstream-side supporting region end 24A of the oxidizing
catalyst 24 coincides with the upstream-side supporting region end
22A of the reforming catalyst 22, or is positioned a bit further
downstream than the upstream-side supporting region end 22A.
[0097] With regard to the heat exchange reformer unit 10, as shown
in FIGS. 5A and 5B, a catalyst carrier is applied on the divided
passages 58 of the reforming passage 18 and the divided passages 64
of the combustion passage 20 by immersing the multilayer core unit
65, from the end thereof on the gas outlet 50B-side, or 51B-side,
into a slurry-like catalyst carrier 75 stored in a storage tank 76.
Then, the catalyst carrier 75 applied on the divided passages 58
and 64 is caused to support the reforming catalyst 22 and the
oxidizing catalyst 24, respectively. In order to stop the catalyst
carrier at the upstream-side supporting region ends 22A and 24A
(control line), the detection signal from a catalyst sensor or
sensors 74 for detecting the catalyst carrier, which are provided
in representative ones of or all of the divided passages 58 and 64,
is used. A method of producing the heat exchange reformer unit 10
will be specifically described below.
[0098] When the heat exchange reformer unit 10 is produced, as
shown in FIG. 3, the unit plate members 50 and 51 are alternately
stacked, and the free edges of the outer walls 54 and 60 are bonded
to the plate portions 52 of the adjacent unit plate members 51 and
50, respectively. Thus, the multilayer core unit 65 is formed.
Next, as shown in FIG. 5A, the catalyst-supporting region position
sensors 74 are set on the divided passages 58 and 64 of the
multilayer core unit 65. The catalyst-supporting region position
sensor 74 is designed to output an ON signal to a notification
device (not shown), such as a display device and notification
sound-generating device, when the catalyst carrier is brought into
contact with a slurry-detecting portion 74A provided on the tip of
the sensor. Thus, the catalyst-supporting region position sensors
74 are inserted into representative ones of the divided passages 58
and 64 from the gas inlet 50A-side, or 51A-side so that the
slurry-detecting portions 74A are positioned at the desired
positions to which the upstream-side supporting region end 22A of
the reforming catalyst 22 and the upstream-side supporting region
end 24A of the oxidizing catalyst 24 on the divided passages 58 and
64 are controlled.
[0099] The multilayer core unit 65 in which the catalyst-supporting
region position sensors 74 are set is immersed into the catalyst
carrier 75 in the storage tank 76 from the gas outlet-SOB, or
51B-side. In consideration of the fact that, in the multilayer core
unit 65 having a microchannel structure, the level of the surface
of the catalyst carrier 75 in the divided passages 58 and 64
becomes higher than the level thereof in the storage tank 76 due to
the capillary phenomenon, the multilayer core unit 65 is gradually
(slowly) immersed into the catalyst carrier 75 until a notification
is made by the notification device (until the catalyst-supporting
region position sensor(s) 74 detects the catalyst carrier 75), as
shown in FIGS. 5A and 5B. After the activation of the notification
device, the multilayer core unit 65 is drawn out of the storage
tank 76, and the surplus catalyst carrier 75 is removed from the
divided passages 58 and 64 by blowing air thereinto through the gas
inlets 50A and 51A, for example.
[0100] Subsequently, as shown in FIG. 5C, the reforming catalyst 22
is supplied into the divided passages 58 through the gas outlets
50B to cause the catalyst carrier 75 in the divided passages 58 to
support the reforming catalyst 22. Then, the oxidizing catalyst 24
is supplied into the divided passages 64 through the gas outlets
51B to cause the catalyst carrier 75 in the divided passages 64 to
support the oxidizing catalyst 24. Thus, the multilayer core unit
65 is constructed in which the reforming catalyst 22 is supported
in the heat-exchanging passages 58A and the reformate gas guide
passages 58C of the divided passages 58 but is not supported in the
reformation material guide passages 58B, and in which the oxidizing
catalyst 24 is supported in the heat-exchanging passages 64A and
the combustion exhaust gas guide passages 64C of the divided
passages 64 but is not supported in the mixed gas guide passages
64B.
[0101] Then, the reformation inlet manifold 66, the combustion
inlet manifold 70, the reformation outlet manifold 68, and the
combustion outlet manifold 72 are respectively joined to the
opening portions of the gas inlets 50A and 51A, and the gas outlets
50B and 51B of the respective layers of the multilayer core unit
65. Thus, the production process of the heat exchange reformer unit
10 as shown in FIG. 3 is completed.
[0102] Next, operations of the first embodiment will be
described.
[0103] In the fuel cell system 11 with the above construction,
operating the material pump 26 and the cathode air pump 36 causes
hydrocarbon material and steam (cathode off-gas) to be introduced
into the reforming passages 18 of the heat exchange reformer unit
10 through the material supply line 28. In the reforming passages
18 of the heat exchange reformer unit 10, the reforming reactions
including the steam-reforming reaction expressed by the equation
(1) and the partial oxidation reaction expressed by the equation
(2) (see the above equations (1) to (4)) are caused by bringing the
introduced hydrocarbon material and steam into contact with the
reforming catalyst 22 with heat supplied from the combustion
passages 20, so that reformate gas that contains hydrogen in high
concentration is produced.
[0104] The reformate gas produced in the reforming passages 18 is
supplied to the anode electrode 14 through the fuel inlet 14A of
the anode electrode 14. In the fuel cell 12, hydrogen in the
reformate gas supplied to the anode electrode 14 is turned into
protons, and the protons migrate to the cathode electrode 16
through the electrolyte to react with oxygen in the air introduced
onto the cathode electrode 16. As the protons migrate in this way,
electrons flow from the anode electrode 14 toward the cathode
electrode 16 through the external conductor, so that electricity is
generated.
[0105] In the fuel cell 12, the generation of electricity uses
hydrogen in the reformate gas supplied to the anode electrode 14
and oxygen in the cathode air supplied to the cathode electrode 16
in accordance with the amount of electricity generated (the
electric power consumption of a load), and water (steam under
operating temperature conditions) is produced at the cathode
electrode 16. The gas that contains steam is expelled from the
cathode electrode 16 to the steam supply line 40 as cathode off-gas
as described above, and introduced into the reforming passage 18
through the steam inlet 18C.
[0106] The gas resulting after hydrogen in the reformate gas is
used according to the amount of generated electricity as
electricity is generated, is discharged from the anode electrode 14
as anode off-gas. The anode off-gas is supplied to the combustion
passages 20 of the heat exchange reformer unit 10 through the anode
off-gas line 32. In addition, the coolant off-gas after cooling the
fuel cell 12 is supplied to the combustion passages 20 through the
combustion-supporting gas supply line 46. In the combustion
passages 20, catalytic combustion is caused by bringing the
combustible components in the anode off-gas, which is fuel, into
contact with the oxidizing catalyst 24 together with the oxygen in
the coolant off-gas as the combustion-supporting gas. The heat
produced by the catalytic combustion is supplied to the reforming
passages 18 through the plate portions 52. Using the heat, in the
reforming passages 18, the reforming reactions, which are
endothermic reactions, are maintained, and the operating
temperature (reformate gas temperature) is maintained at a
temperature required to bring about reforming reactions.
[0107] In this way, the fuel cell system 11 supplies hydrocarbon
material to the heat exchange reformer unit 10, and effectively
uses various exhaust gases of the fuel cell 12 (the cathode off-gas
that contains steam, the anode off-gas that contains combustible
components, and the coolant off-gas that contains oxygen) to
maintain the operation of the heat exchange reformer unit 10, which
produces hydrogen that is supplied to the fuel cell 12.
[0108] The reforming reactions in the reforming passages 18 have an
endothermic peak on the reformation material inlet side, that is,
on the upstream-side catalyst-supporting region 22A-side of the
region in which the reforming catalyst 22 is supported. The burning
reactions in the combustion passages 20 have an exothermic peak on
the fuel inlet side, that is, on the upstream-side
catalyst-supporting region 24A-side of the region in which the
reforming catalyst 24 is supported. Thus, in cross-flow heat
exchange reformer units, for example, the gas flow directions in a
reforming section and a heating section intersect with each other,
and therefore, there is a problem that local high-temperature
regions occur due to the structure. Meanwhile, in counter-flow heat
exchange reformer units, for example, an endothermic peak and an
exothermic peak in a reforming section and a heating section occur
at opposite end portions with respect to the gas flow direction in
a heat exchanging section, and therefore, counter-flow heat
exchange reformer units are not suitable for the heat exchangers in
reformers.
[0109] With regard to the heat exchange reformer unit 10, a
parallel-flow heat exchanger, in which the gas flow direction in
the heat-exchanging passages 58A of the reforming passage 18 and
the gas flow direction in the heat-exchanging passages 64A of the
combustion passage 20 are the same, is constructed, that is, it is
possible to set an endothermic peak and an exothermic peak on the
same side with respect to the gas flow direction, wherein, in the
reforming reactions, the endothermic peak occurs on the gas inlet
50A-side to which reformation material is supplied, and, in the
combustion reactions, the exothermic peak occurs on the gas inlet
51A-side to which fuel is supplied. Accordingly, the efficiency of
heat exchange between the reforming passages 18 and the combustion
passages 20 is enhanced. Thus, with the heat exchange reformer unit
10, it is possible to efficiently produce hydrogen by reforming,
using heat generated in the combustion passage 20 effectively.
[0110] Thus, in the heat exchange reformer unit 10 according to the
first embodiment, the efficiency of heat exchange between the
combustion passages 20 and the reforming passages 18 is
excellent.
[0111] In addition, in the heat exchange reformer unit 10, the
reformation material guide passages 58B and the mixed gas guide
passages 64B, which are located on the upstream side of the
heat-exchanging passages 58A and 64A substantially constituting a
parallel-flow heat exchanger, constitute a cross-flow heat
exchanging section, so that the heat exchange therein enables
stable operation against fluctuation (robustness is enhanced). An
experimental example is shown in FIG. 6. FIG. 6 is a diagram
showing a temperature distribution at points along the gas flow
direction in the divided passages 64 when the temperature of the
mixed gas supplied is at a constant temperature of 400.degree. C.
The solid line represents the case where the temperature of the
reformation material supplied to the divided passages 58 is
600.degree. C., and the dashed line represents the case where the
temperature of the reformation material supplied to the divided
passages 58 is 400.degree. C. From this figure, it can be seen
that, even when the temperature of the gas flowing into the divided
passages 58 varies by 200.degree. C., the increase in the highest
temperature in the divided passages 64 is restricted to 30.degree.
C. That is, the heat exchange reformer unit 10 makes it possible to
effectively suppress sharp variation in the temperature of the
reaction field depending on the gas inlet temperature.
[0112] In the heat exchange reformer unit 10, the reforming
catalyst 22 and the oxidizing catalyst 24 are not supported in the
cross-flow heat exchanging section, which is constituted of the
reformation material guide passages 58B and the mixed gas guide
passages 64B, and therefore, neither a reforming reaction nor a
combustion reaction occurs in the reformation material guide
passages 58B and the mixed gas guide passages 64B. Accordingly, the
occurrence of local high-temperature regions due to the unbalance
between the positions of the endothermic region and the exothermic
region is prevented, which is a problem arising when a cross-flow
heat exchange reformer unit is used. Experimental results have been
obtained that show that, while, in the case where the reforming
catalyst 22 and the oxidizing catalyst 24 are supported in the
reformation material guide passages 58B and the mixed gas guide
passages 64B, respectively, the maximum temperature in the
reformation material guide passages 58B is about 800.degree. C.
when the temperature of the reformate gas discharged from the
divided passages 58 (reformation outlet manifold 68) is controlled
at 650.degree. C., the maximum temperature in the reformation
material guide passages 58B in the heat exchange reformer unit 10
is about 180.degree. C. under the same conditions.
[0113] Thus, by providing the cross-flow heat exchanging section
(quasi-cross-flow section), which is constituted of the reformation
material guide passages 58B and the mixed gas guide passages 64B,
upstream of the parallel-flow heat-exchanging section, which is
constituted of the heat-exchanging passages 58A and the
heat-exchanging passages 64A, it is made possible to realize an
ideal reaction field (thermal balance) in the reforming passages 18
and the combustion passages 20, and in addition, the improvement in
the robustness of the system is achieved.
[0114] In addition, because the region in which the catalyst
carrier 75 is provided, that is, the region in which the reforming
catalyst 22 and the oxidizing catalyst 24 are supported, is
controlled using the catalyst-supporting region position sensor 74,
it is possible to accurately form the upstream-side supporting
region ends 22A and 24A of the reforming catalyst 22 and the
oxidizing catalyst 24. Specifically, although, with regard to the
multilayer core unit 65 in which multiple unit plate members 50 and
51 are stacked, it is infeasible to see the inside of the divided
passages 58 and 64, it is possible to prevent the situation where
catalyst is supported in the reformation material guide passages
58B and the mixed gas guide passages 64B as shown in FIG. 7A, the
situation where the amount of catalyst supported in the
heat-exchanging passages 58A and 64A is insufficient as shown in
FIG. 7B, and the situation where the regions in which the reforming
catalyst 22 and the oxidizing catalyst 24 are supported are
significantly different from each other as shown in FIG. 7C, by
using the catalyst-supporting region position sensor 74.
[0115] Moreover, in the multilayer core unit 65 of the heat
exchange reformer unit 10, the reformation material guide passages
58B and the mixed gas guide passages 64B, which are positioned
upstream of the heat-exchanging passages 58A and 64A substantially
constituting a parallel-flow heat exchanger, constitute a
cross-flow (quasi-cross-flow) section, so that it is possible to
form the gas inlets 50A, whose surface planes in the respective
layers are substantially on the same plane, and the gas inlet 51A,
whose surface planes in the respective layers are substantially on
the same plane, in the form of separate opening portions that are
open toward different directions. Thus, a construction is realized,
in which, while a parallel-flow configuration is adopted that shows
an excellent balance between heat generation and heat absorption as
described above, the reformation inlet manifold 66 that defines the
collection space to which the gas inlets 50A of the respective
layers are open is connected to the multilayer core unit 65, and
the combustion inlet manifold 70 that defines the collection space
to which the gas inlets 51A of the respective layers are open is
connected to the multilayer core unit 65. Accordingly, it is
possible to improve the homogeneity of the distribution of the
amount of gas flowing into the divided passages 58 and 64, as
compared to the configuration in which reformation material and
mixed gas (anode off-gas as fuel) are supplied to the gas inlets
50A and 51A of the respective layers individually.
[0116] In particular, when the combustion inlet manifold 70 is
provided, it is made possible to dispose the gas mixer 33, which
supplies mixed gas to the divided passages 64 (combustion passages
20), immediately before the gas inlets 51A. When such a gas mixer
33 is structured in the form of a mixing space provided downstream
of the microchannel structure, which is constructed by alternately
stacking such unit plates as obtained by removing the flow
direction-changing section 52C and the outlet guide walls 56C or
62C from the unit plate members 50 and 51, it is made possible to
dispose, or form, the gas mixer 33 in the combustion inlet manifold
70 (or in a pipe with a rectangular cross-section connected to the
combustion inlet manifold 70).
[0117] In the multilayer core unit 65 of the heat exchange reformer
unit 10, the reformate gas guide passages 58C and the combustion
exhaust gas guide passages 64C, which are positioned downstream of
the heat-exchanging passages 58A and 64A substantially constituting
a parallel-flow heat exchanger, constitute a cross-flow
(quasi-cross-flow) section, so that it is possible to form the gas
outlets 50B and 51B in the form of separate opening portions that
are open toward different directions. Thus, a construction is
realized, in which, while a parallel-flow configuration is adopted
that shows an excellent balance between heat generation and heat
absorption as described above, the reformation outlet manifold 68
that defines the collection space to which the gas outlets 50B of
the respective layers are open is connected to the multilayer core
unit 65, and the combustion outlet manifold 72 that defines the
collection space to which the gas outlets 51B of the respective
layers are open is connected to the multilayer core unit 65.
Accordingly, in cooperation with the effect caused by providing the
reformation inlet manifold 66 and the combustion inlet manifold 70
described above, it is possible to further improve the homogeneity
of the distribution of the amount of gas flowing into the divided
passages 58 and 64, as compared to the configuration in which
reformate gas and combustion exhaust gas are discharged from the
gas outlets 50B and 51B of the respective layers individually.
[0118] In addition, in the above embodiments, examples provided
with the unit plate members 50 and 51 in each of which the
substantially rectangular-parallel flow section 52A (the
heat-exchanging passages 58A and 64A) is integrated with the
substantially triangular-flow direction-changing sections 52B and
52C (the gas guide passages 58B and 58C, and 64B and 64C) are
illustrated. However, the present invention is not limited to these
examples, and the flow direction-changing sections 52B and 52C with
various shapes may be provided. In addition, the configuration of
the guide walls 56B and the like that constitute the gas guide
passages 58B and the like together with the flow direction-changing
section 52B and the like is not limited to a configuration having a
straight shape. The guide walls 56B and the like may have a curved
shape, for example.
[0119] A heat exchange reformer unit 10 according to a second
embodiment of the present invention will be described with
reference to FIGS. 1, 4 and 8A to 11. FIG. 8A shows the multilayer
core unit 65, which is a main component of the heat exchange
reformer unit 10, in a front view in section. FIG. 9 shows the
multilayer core unit 65 in an exploded perspective view. As shown
in these figures, in the multilayer core unit 65 of the heat
exchange reformer unit 10, the reforming passages 18 as the
reforming sections, and the combustion passages 20 as the heating
sections are formed in the form of separate gas passages between
the unit plate members 50 and 51, which are provided as a plurality
of reforming section-forming plate members and a plurality of
heating section-forming plate members, which are stacked, wherein
the reforming passages 18 and the combustion passages 20 are
separated by the plate portions 52 as separation walls, which may
be regarded as flat-shaped plate portions of unit plate members 50
and 51. The multilayer core unit 65 has a configuration in which
the number of layers of the reforming passages 18 and the number of
layers of the combustion passages 20 differ from each other.
Specific description will be given below.
[0120] The unit plate member 50 includes the plate portion 52
formed in a flat shape. As shown in FIG. 9, the plate portion 52 is
formed by providing, at both ends in the longitudinal direction of
the parallel flow portion 52 as the heat exchanging section, which
is formed in the rectangular shape, the flow direction-changing
sections 52B and 52C, individually, in a continuous manner, when
viewed from above. In this embodiment, the flow direction-changing
sections 52B and 52C are formed in a triangular shape such that the
bases thereof are made to coincide with the corresponding short
sides of the parallel flow portion 52A (with a rectangular shape).
Accordingly, the plate portion 52 as a whole is formed in a
substantially hexagonal shape. Each unit plate member 50 includes
the outer walls 54, which are provided in a standing condition at
edges of the plate portion 52 on the side thereof on which the
reforming passages 18 are formed.
[0121] The outer walls 54 are provided in a standing condition all
around the plate portion 52 except one side portion of each of the
direction-changing sections 52B and 52C, so that the outer walls 54
function as spacers that define the reforming passages 18 between
the stacked unit plate members 50 and 51, and also function as
outer walls that prevent the outflow of gas from the reforming
passages 18, and, at the same time, create the gas inlet 50A on the
flow-direction changing section 52B-side, and the gas outlet SOB on
the flow-direction changing section 52C-side. The gas inlet 50A and
the gas outlet 50B are formed symmetrically with respect to the
centroid of the plate portion 52, and the openings thereof are
oriented in the directions indicated by the arrows C1 and C2,
respectively, which are opposite to the direction of the parallel
flow portion 52A, which extends along the longitudinal direction of
the outer walls 54, in the flow-direction changing sections 52B and
52C.
[0122] A plurality of standing walls (partition walls) 56 that
divide the reforming passage 18 into a plurality of parallel
passages are provided in a standing condition on the side of the
plate portion 52 of the unit plate members 50 on which the
reforming passage 18 is formed. The standing walls 56 are made
substantially parallel with the outer walls 54 from the gas inlet
50A to the gas outlet 50B, and are configured so as to divide the
reforming passage 18 into the plurality of divided passages
(microchannels) 58. Each divided passage 58 is formed in a
crank-like shape such that the length of the passages from the gas
inlet 50A to the gas outlet SOB is substantially the same owing to
the symmetrical arrangement of the gas inlet 50A and the gas outlet
50B described above.
[0123] The part of the divided passages 58 in the parallel flow
portion 52A that are separated by partition wall portions 56A of
the standing walls 56 lying along the longitudinal direction of the
parallel flow portions 52A, serve as heat-exchanging passages 58A.
Meanwhile, the part of the divided passages 58 between which inlet
guide walls 56B are provided on the flow-direction changing section
52B in a standing condition, serve as reformation material guide
passages 58B constituting a reformation material guide section. The
inlet guide walls 56B are part of the standing walls 56, and lie
along the direction indicated by the arrow C1. In addition, the
part of the divided passages 58 between which outlet guide walls
56C are provided on the flow-direction changing section 52C in a
standing condition, serve as reformate gas guide passages 58C
constituting a reformate gas guide section. The outlet guide walls
56C are part of the standing walls 56, and lie along the direction
indicated by the arrow C2.
[0124] The unit plate member 51 includes the plate portion 52 that
has the same shape as that of the plate portion 52 constituting the
unit plate member 50, and includes the outer walls 60, which are
provided in a standing condition at the periphery of the plate
portion 52 on the side thereof on which the combustion passages 20
are formed. The outer walls 60 are provided in a standing condition
all around the plate portion 52 except one side portion of each of
the direction-changing sections 52B and 52C, so that the outer
walls 60 function as spacers that form the combustion passages 20
between the stacked unit plate members 50 and 51, and also function
as outer walls that prevent the outflow of gas from the combustion
passages 20, and so that the outer walls 60 form the gas inlet 51A
on the flow-direction changing section 52B-side, and the gas outlet
51B on the flow-direction changing section 52C-side.
[0125] The gas inlet 51A is formed on the same side of a parallel
flow portion 52A in the longitudinal direction as the gas inlet 50A
of the unit plate member 50 (that is, on the side indicated by the
arrow A in FIG. 9) so as to be open toward the direction indicated
by the arrow D1, which is different from the direction indicated by
the arrow C1 (that is, which is symmetric with respect to the
longitudinal axis of the parallel flow portion 52A). Meanwhile, the
gas outlet 51B is formed on the same side of a parallel flow
portion 52A in the longitudinal direction as the gas inlet 50A of
the unit plate member 50 (that is, on the side indicated by the
arrow B in FIG. 9) so as to be open toward the direction indicated
by the arrow D2, which is different from the direction indicated by
the arrow C2 (that is, which is symmetric with respect to the
longitudinal axis of the parallel flow portion 52A), toward which
the gas outlet SOB is open.
[0126] The plurality of standing walls (partition walls) 62 that
divide the combustion passage 20 into a plurality of parallel
passages are provided in a standing condition on the combustion
passage 20-formed-side of the plate portion 52 of the unit plate
members 51. The standing walls 62 are made substantially parallel
with the outer walls 60 from the gas inlet 51A to the gas outlet
51B, and are configured so as to divide the combustion passage 20
into the plurality of divided passages (microchannels) 64. Each
divided passage 64 is formed in a crank-like shape such that the
length of the passages from the gas inlet 51A to the gas outlet 51B
is substantially the same owing to the symmetrical arrangement of
the gas inlet 51A and the gas outlet 511B described above.
[0127] In the divided passages 64, the portions in the parallel
flow portion 52A that are separated by partition wall portions 62A
of the standing walls 62 lying along the longitudinal direction of
the parallel flow portions 52A, are made to serve as
heat-exchanging passages 64A. Meanwhile, the part of the divided
passages 64 that are created by providing, as part of the standing
walls 62, inlet guide walls 62B on the flow-direction changing
section 52B in a standing condition that lie along the direction
indicated by the arrow D1, are made to serve as mixed gas guide
passages 64B constituting a fuel guide section. In addition, the
part of the divided passages 64 that are created by providing, as
part of the standing walls 62, outlet guide walls 62C on a
flow-direction changing section 52C in a standing condition that
lie along the direction indicated by the arrow D2, are made to
serve as combustion exhaust gas guide passages 64C constituting a
combustion exhaust gas guide section.
[0128] In the heat exchange reformer unit 10 described above, the
multilayer core unit 65 is constructed by stacking the unit plate
members 50 and 51 in the following manner: the gas inlets 50A and
51A are positioned on the same side (that is, on the side indicated
by the arrow A) of the parallel flow portion 52A (the
heat-exchanging passages 58A and 64A), and the gas outlets 50B and
51B are positioned on the same side (that is, on the side indicated
by the arrow B) of the parallel flow portion 52A as described
above, so that the directions in which gas flows in the
heat-exchanging passages 58A and 64A on the respective layers are
set to the same direction (the direction indicated by the arrow
F).
[0129] As shown in FIGS. 8A and 9, in this embodiment, the
multilayer core unit 65 is constructed by stacking two unit plate
members 50 (two layers of the reforming passages 18) per one unit
plate member 51 (one layer of the combustion passage 20).
Specifically, in the multilayer core unit 65, by stacking the
units, in each of which two unit plate members 50 are stacked on
the same side of one unit plate member 51, or the units, in each of
which one unit plate member 51 is sandwiched between the unit plate
members 50 in the stacking direction, two layers of the reforming
passages 18 are disposed between a pair of the combustion passages
20 such that a combustion passage 20 is not adjacent to another
combustion passage 20 in the stacking direction, as shown in FIG.
8B. Accordingly, in the multilayer core unit 65, the reforming
passage 18 of each layer is, on any one side thereof, adjacent to a
combustion passage 20 with a plate portion 52 interposed
therebetween.
[0130] In each of the unit plate members 50 and 51 described above,
the portions (the plate portion 52, the outer walls 54 and the
standing walls 56; or the plate portion 52, the outer walls 60 and
the standing walls 62) are integrally formed of metallic materials,
such as stainless steel, or solid (not porous) ceramics, for
example. The plurality of the unit plate members 50 and the
plurality of the unit plate members 51 constitute the multilayer
core unit 65 of the heat exchange reformer unit 10, wherein the
plate members 52 and the outer walls 54 and 60 (the standing walls
56 and 62) are airtightly joined by brazing using brazing filler or
by diffusion bonding, for example. As shown in FIG. 10, in the heat
exchange reformer unit 10, in this embodiment, a flat-shaped plate
portion 52 (cover) on which the outer walls 54 or the like are not
provided in a standing condition is placed on the top of the heat
exchange reformer unit 10 so as to close the reforming passage
18.
[0131] As shown in FIG. 10, a reformation inlet manifold 66 that
defines a collection space to which the gas inlets 50A of the
respective layers are open is connected to the multilayer core unit
65. In addition, a reformation outlet manifold 68 that defines a
collection space to which the gas outlets 50B of the respective
layers are open is connected to the multilayer core unit 65.
Moreover, a combustion inlet manifold 70 that defines a collection
space to which the gas inlets 51A of the respective layers are open
is connected to the multilayer core unit 65. Furthermore, a
combustion outlet manifold 72 that defines a collection space to
which the gas outlets 51B of the respective layers are open is
connected to the multilayer core unit 65. Each of the manifolds 66,
68, 70 and 72 is formed in a rectangular tube shape, and one open
end thereof is joined to the end portions of the top and bottom
plate portions 52, and the end portions of the outer walls 54 and
60 of the respective layers by brazing, for example.
[0132] Although not shown in the figures, the material inlet 18A
and the steam inlet 18C for introducing reformation material
(hydrocarbon) and steam (cathode off-gas), respectively, are
provided in the reformation inlet manifold 66, and the reformate
gas outlet 19B for discharging reformate gas is provided in the
reformation outlet manifold 68. Meanwhile, the fuel inlet 20A for
introducing mixed gas from the gas mixer 33 is provided in the
combustion inlet manifold 70, and the exhaust gas outlet 20B for
discharging combustion exhaust gas is provided in the combustion
outlet manifold 72.
[0133] In the heat exchange reformer unit 10 (multilayer core unit
65) described above, the reforming catalyst 22 is supported on the
inner surface of the divided passages 58 on the unit plate member
50, and the oxidizing catalyst 24 is supported on the inner surface
of the divided passages 64 on the unit plate member 51. As shown in
FIG. 4, which is an exploded plan view in which the illustration of
the standing walls 56 and 62 is omitted, the reforming catalyst 22
is supported in the divided passages 58 (reforming passage 18) in a
predetermined region thereof that does not include part of the
divided passages 58 on the gas inlet 50A-side, and the oxidizing
catalyst 24 is supported in the divided passages 58 (combustion
passage 20) in a predetermined region thereof that does not include
part of the divided passages 64 on the gas inlet 51A-side.
[0134] More specifically, with regard to the reforming catalyst 22,
an upstream-side supporting region end 22A that is the end on the
upstream side (that is, on the side indicated by the arrow A) in
the gas flow direction in which the reformation material is
supplied, substantially coincides with the border between the
heat-exchanging passages 58A (parallel flow section 52A) and the
reformation material guide passages 58B (flow direction-changing
section 52B) of the divided passages 58. With regard to the
oxidizing catalyst 24, an upstream-side supporting region end 24A
that is the end on the upstream side (that is, on the side
indicated by the arrow A) in the gas flow direction, in which the
fuel is supplied, substantially coincides with the border between
the heat-exchanging passages 64A (parallel flow section 52A) and
the mixed gas guide passages 64B (flow-direction changing section
52B) of the divided passages 64. It should be noted that the
upstream-side supporting region end 24A of the oxidizing catalyst
24 coincides with the upstream-side supporting region end 22A of
the reforming catalyst 22, or is positioned a bit further
downstream than the upstream-side supporting region end 22A.
[0135] Next, the operations of the second embodiment will be
described.
[0136] In the fuel cell system 11 with the above construction,
operating the material pump 26 and the cathode air pump 36 causes
hydrocarbon material and steam (cathode off-gas) to be introduced
into the reforming passages 18 of the heat exchange reformer unit
10 through the material supply line 28. In the reforming passages
18 of the heat exchange reformer unit 10, the reforming reactions
including the steam-reforming reaction expressed by the equation
(1) and the partial oxidation reaction expressed by the equation
(2) (see the above equations (1) to (4)) are caused by bringing the
introduced hydrocarbon material and steam into contact with the
reforming catalyst 22 with heat supplied from the combustion
passages 20, so that reformate gas that contains hydrogen in high
concentration is produced.
[0137] The reformate gas produced in the reforming passages 18 is
supplied to the anode electrode 14 through the fuel inlet 14A of
the anode electrode 14. In the fuel cell 12, hydrogen in the
reformate gas supplied to the anode electrode 14 is turned into
protons, and the protons migrate to the cathode electrode 16
through the electrolyte to react with oxygen in the air introduced
onto the cathode electrode 16. As the protons migrate in this way,
electrons flow from the anode electrode 14 toward the cathode
electrode 16 through the external conductor, so, that electricity
is generated.
[0138] In the fuel cell 12, the generation of electricity uses
hydrogen in the reformate gas supplied to the anode electrode 14
and oxygen in the cathode air supplied to the cathode electrode 16
in accordance with the amount of electricity generated (the
electric power consumption of a load), and water (steam under
operating temperature conditions) is produced at the cathode
electrode 16. The gas that contains steam is expelled from the
cathode electrode 16 to the steam supply line 40 as cathode off-gas
as described above, and introduced into the reforming passage 18
through the steam inlet 18C.
[0139] The gas resulting after hydrogen in the reformate gas is
used according to the amount of generated electricity as
electricity is generated, is discharged from the anode electrode 14
as anode off-gas. The anode off-gas is supplied to the combustion
passages 20 of the heat exchange reformer unit 10 through the anode
off-gas line 32. In addition, the coolant off-gas after cooling the
fuel cell 12 is supplied to the combustion passages 20 through the
combustion-supporting gas supply line 46. In the combustion
passages 20, catalytic combustion is caused by bringing the
combustible components in the anode off-gas, which is fuel, into
contact with the oxidizing catalyst 24 together with the oxygen in
the coolant off-gas as the combustion-supporting gas. The heat
produced by the catalytic combustion is supplied to the reforming
passages 18 through the plate portions 52. Using the heat, in the
reforming passages 18, the reforming reactions, which are
endothermic reactions, are maintained, and the operating
temperature (reformate gas temperature) is maintained at a
temperature required to bring about reforming reactions.
[0140] In this way, the fuel cell system 11 supplies hydrocarbon
material to the heat exchange reformer unit 10, and effectively
uses various exhaust gases of the fuel cell 12 (the cathode off-gas
that contains steam, the anode off-gas that contains combustible
components, and the coolant off-gas that contains oxygen) to
maintain the operation of the heat exchange reformer unit 10, which
produces hydrogen that is supplied to the fuel cell 12.
[0141] Because the combustion reactions in the combustion passage
20 have high reaction velocities, a reaction field is mainly
created on the fuel inlet side, that is, on the upstream-side
supporting region end 24A-side of the region in which the oxidizing
catalyst 24 is supported, as shown in FIG. 11. On the other hand,
the reforming reactions in the reforming passage 18 (the reactions,
the main reaction of which is steam-reforming reaction) have
reaction velocities significantly slower than those of the
combustion reactions, and therefore, a reaction field of reforming
reactions is created (maintained) from the material inlet 18A (the
upstream-side supporting region end 22A of the reforming catalyst
22) up to the vicinity of the reformate gas outlet 18B.
Accordingly, the knowledge that the amount of the reforming
reaction that can be carried out in a unit volume of space is less
than the amount of the combustion reaction that take place in the
unit volume of space has been obtained.
[0142] In the heat exchange reformer unit 10, the number of the
stacked layers (channels) of the reforming passages 18 is larger
than the number of the stacked layers of the combustion passages
20. Thus, the increase in the volume (ratio) of the reforming
passage 18 (divided passages 58) is achieved while keeping the
overall volume (the sum of the total volume of the reforming
passages 18 and the total volume of the combustion passages 20)
unchanged. As a result, in the heat exchange reformer unit 10, the
total amount of the reforming reaction in the reforming passages 18
and the total amount of the combustion reaction in the combustion
passages 20 are matched (the amount of reforming reaction and the
amount of combustion reaction are set according to the reforming
reaction field), which realizes the operation at high space
velocities, Assuming that the overall volume (m.sup.3) of the heat
exchange reformer unit 10 is Va, the feed flow rate of the
reformation material is Qr (m.sup.3/h), the total volume of the
reforming passages 18 (all the divided passages 58) is Vr, and the
total volume of the combustion passages 20 (all the divided
passages 64) is Vc, the space velocity SV is defined by the
equation, SV(1/h)=Qr/Va=Qr/(Vr+Vc). The operations and effects of
the heat exchange reformer unit 10 will be described while
comparing it with a comparative example shown in FIGS. 22A and
22B.
[0143] A heat exchange reformer unit 200 according to the
comparative example shown in FIGS. 22A and 22B is constructed by
alternately stacking reforming passages 18 and combustion passages
20. Accordingly, in the heat exchange reformer unit 200, the ratio
of the volume of the reforming passages 18 to the volume of the
heat exchange reformer unit 200 (overall volume) is about 50% (see
the " 1/1" (layer ratio) bar in the graph of FIG. 12). Meanwhile,
the reforming reactions, which have low reaction velocities as
mentioned above, require a certain reaction space. Accordingly, it
is difficult to achieve a high space velocity for reformation
material by using the heat exchange reformer unit 200.
Specifically, when the amount of reformation material supplied to
the reforming passages 18 is increased to realize operation at high
space velocities, the speed of flow of gas in the reforming
passages 18 is increased. As a result, the time for reaction
(reaction field) of the reforming reactions, which have low
reaction velocities, cannot be secured, and the reforming
efficiency is therefore reduced.
[0144] On the other hand, in the heat exchange reformer unit 10,
two layers of the reforming passages 18 are stacked per one layer
of the combustion passage 20, so that the ratio of the volume of
the reforming passages 18 to the overall volume of the heat
exchange reformer unit 10 increases to about 67% as shown in FIG.
12 (see the "2/1" (layer ratio) bar in the graph). In addition,
because the volume of the reforming passage 18 per layer is
constant in the heat exchange reformer unit 10 in which the
multilayer core unit 65 is formed by stacking the unit plate
members 50 and 51, the inner surface area of the reforming passages
18, that is, the area of the region, in which the reforming
catalyst 22 is supported, that is, the amount of catalyst
supported, increases by about 34% as compared to the heat exchange
reformer unit 200 that has the layer ratio of 1/1 (see the " 1/1"
(layer ratio) bar in the graph of FIG. 13), as shown in FIG. 13
(see the " 2/1" (layer ratio) bar in the graph).
[0145] As described above, with the heat exchange reformer unit 10,
a higher space velocity as compared to that of the heat exchange
reformer unit 200 is achieved, that is, a construction with which
operation at high space velocities (increase in the amount of
reformation material supplied) contributes to the improvement of
the reforming efficiency, is realized. FIG. 14 shows a relation
between the proportion of the region occupied by the reforming
passages 18 (volume, or the surface area of the region in which the
reforming catalyst 22 is supported) and the conversion ratio
(reformation ratio) when the space velocity is constant (about
50000/h). The conversion ratio represents the proportion in which
the hydrocarbon, which is reformation material, is converted into
carbon monoxide, carbon dioxide, or methane. When the
steam-reforming reaction expressed by the above equation (1) is
completely carried out (that is, when the amount of hydrocarbon
other than methane in the reformate gas is zero), the conversion
ratio is defined as one (100%).
[0146] As shown in FIG. 14, under the operating conditions in which
the temperature of the reformate gas at the outlet is 650.degree.
C., the conversion ratio of the heat exchange reformer unit 10 (in
which the ratio of the volume occupied by the reforming passages 18
is 67%) is improved by about 10% as compared to that of the heat
exchange reformer unit 200 (in which the same volume ratio is
50%).
[0147] In this way, the heat exchange reformer unit 10 according to
the second embodiment improves the reforming efficiency.
[0148] Next, other embodiments of the present invention will be
described. It should be noted that basically the same
components/portions as those of the second embodiment, or the
foregoing construction are denoted by the same reference numerals
as those of the second embodiment, or the foregoing construction,
and the description thereof will be omitted. In some cases, the
illustration thereof will also be omitted.
Third Embodiment
[0149] FIG. 15A shows a heat exchange reformer unit 80 according to
a third embodiment in a front view in section corresponding to FIG.
8A. As shown in FIG. 15A, the heat exchange reformer unit 80
differs from the heat exchange reformer unit 10, which includes the
multilayer core unit 65 in which two layers of the reforming
passages 18 are stacked per one layer of the combustion passage 20,
in that the heat exchange reformer unit 80 includes a multilayer
core unit 82 in which three unit plate members 50 (three layers of
the reforming passages 18) are stacked per one unit plate member 51
(one layer of the combustion passage 20).
[0150] Specifically, in the multilayer core unit 82, three layers
of the reforming passages 18 are disposed between a pair of the
combustion passages 20, as shown in FIG. 15B, by stacking the
units, in each of which three unit plate members 50 are stacked on
the same side of one unit plate member 51. Accordingly, in the
multilayer core unit 82, one layer of the reforming passage 18 is
disposed so as to be sandwiched between two layers of the reforming
passages 18 each of which is, on any one side thereof, adjacent to
a combustion passage 20 with a plate portion 52 interposed
therebetween, that is, so as not to be adjacent to the combustion
passage 20 on either side of the reforming passage 18.
[0151] As described above, in the multilayer core unit 82 in which
three layers of the reforming passages 18 are stacked per one layer
of the combustion passage 20, the ratio of the volume of the
reforming passages 18 to the overall volume is about 75% as shown
in FIG. 12 (see the " 3/1" bar in the graph). In addition, because
the volume of one layer of the reforming passage 18 is constant in
the heat exchange reformer unit 80, the inner surface area, that
is, the catalyst-supporting region area (supporting amount), of the
combustion passages 20 is increased by about 50% as compared to
that of the heat exchange reformer unit 200 (see the "1/1" bar
(layer ratio) in the graph).
[0152] In the other points, the configuration of the heat exchange
reformer unit 80 is the same as that of the heat exchange reformer
unit 10. Accordingly, as in the case of the heat exchange reformer
unit 10 according to the second embodiment, the heat exchange
reformer unit 80 according to the third embodiment also makes it
possible to match the total amount of the reforming reaction in the
reforming passages 18 and the total amount of the combustion
reaction in the combustion passages 20 (that is, to set the amount
of reforming reaction and the amount of combustion reaction
according to the reforming reaction field), and high space
velocities are therefore achieved. That is, it is possible to
improve reforming efficiency.
[0153] In FIG. 14, results showing that the conversion ratio of the
heat exchange reformer unit 80 (in which the ratio of the volume
occupied by the reforming passages 18 is 75%) (see the open
symbols) is less than that of the heat exchange reformer unit 10
(in which the same volume ratio is 67%) are shown. It is likely
that this results from the fact that the thermal performance of the
heat exchange reformer unit 80 is lower than that of the heat
exchange reformer unit 10 because the heat transport distance from
a combustion passage 20 to the reforming passage 18 that is not
adjacent to any combustion passages 20 on either side of the
reforming passage 18, and at the same time, heat is transported
from one layer of the combustion passage 20 to one and a half layer
of the reforming passages 18 on each side of the combustion passage
20 (to three layers in total). That is, because of the reduction in
the thermal performance (heat transfer-controlled effect), the
conversion ratio is reduced as compared to that of the heat
exchange reformer unit 10 under the operating conditions in which
the space velocity is high and the temperature of the reformate gas
is 650.degree. C.
[0154] It is not illustrated herein but has been experimentally
confirmed that, under the operating conditions in which, for
example, the reforming reaction velocity is low (a larger reaction
space is required), such as when the reformation material
temperature is low, the effect of the increase in the volume of the
reforming passages 18 (the surface area of the region in which the
reforming catalyst 22 is supported) surpasses the effect of the
reduction in the thermal performance, and the conversion ratio of
the heat exchange reformer unit 80 is significantly greater than
the conversion ratio of the heat exchange reformer unit 10.
Fourth Embodiment
[0155] FIG. 16A shows a front view in section of a heat exchange
reformer unit 90 according to a fourth embodiment. FIG. 16B shows a
plan view of the reforming passage 18 (combustion passage 20)
constituting the heat exchange reformer unit 90. As shown in these
figures, the heat exchange reformer unit 90 differs from the heat
exchange reformer unit 80 in including a multilayer core unit 94 in
which such unit plate members 50 and 51 as described below are
stacked. Specifically, in the unit plate member 50, heat
transfer-supporting ribs 92, which constitutes heat
transfer-promoting portions, are provided in a standing condition
between the end portions of the standing walls 56 on the gas inlet
50A-side thereof, and in unit plate members 51, heat
transfer-supporting ribs 92, which constitutes heat
transfer-promoting portions, are provided in a standing condition
between the end portions of the standing walls 62 on the gas inlet
51A-side thereof.
[0156] In the fourth embodiment, the heat transfer-supporting ribs
92 are provided on the plate portions 52 in twos between the
adjacent standing walls 56 (including between an outer wall 54 and
the adjacent standing wall 56) and between the adjacent standing
walls 62 (including between an outer wall 60 and the adjacent
standing wall 62) in a standing condition so that the height of the
standing walls 56 and 62 are equal to each other. The portions at
which the heat transfer-supporting ribs 92 are provided in a
standing condition are set substantially corresponding to the
reaction field in which the combustion reactions mainly occur in
the combustion passages 20, that is, the region in which a large
amount of heat is generated.
[0157] When the plate portions 52 between the layers are regarded
as heat transfer fins, wherein the width of the fin is W, the
thickness of the connecting portions (the standing wall 56, the
standing wall 64 and the heat transfer-supporting rib 92) is d, and
the thermal conductivity is ?, as shown in FIG. 17, providing the
heat transfer-supporting ribs 92 causes the multilayer core unit 94
to have a configuration in which the width W is reduced as compared
to that of the third embodiment. When these are compared in terms
of the fin efficiency shown in FIG. 18, while the fin efficiency of
the multilayer core unit 82 of the heat exchange reformer unit 80
is 0.89, the fin efficiency of the multilayer core unit 94 of the
heat exchange reformer unit 90 is enhanced to 0.98. The arrows in
FIG. 17 show heat transfer paths.
[0158] In the other points, the configuration of the heat exchange
reformer unit 80 is the same as that of the heat exchange reformer
unit 10. Accordingly, as in the case of the heat exchange reformer
unit 10 according to the second embodiment, the heat exchange
reformer unit 90 according to the fourth embodiment also makes it
possible to match the total amount of the reforming reaction in the
reforming passages 18 and the total amount of the combustion
reaction in the combustion passages 20 (that is, to set the amount
of reforming reaction and the amount of combustion reaction
according to the reforming reaction field), and high space
velocities are therefore achieved. That is, it is possible to
improve reforming efficiency.
[0159] In the heat exchange reformer unit 90, the heat
transfer-supporting ribs 92 promote heat transfer from the
combustion passages 20 to the reforming passages 18, especially to
the reforming passages 18 that are not adjacent to the combustion
passages 20 on either side of each reforming passage 18, which
cancels out the reduction in the thermal efficiency (heat-transfer
controlled effect) caused in the case of the third embodiment.
Thus, in the heat exchange reformer unit 90 (in which the ratio of
the volume occupied by the reforming passages 18 is 75%), the
conversion ratio exceeding that of the heat exchange reformer unit
10 is achieved under the operating conditions in which the space
velocity is high and the temperature of the reformate gas is
650.degree. C., as shown by the solid symbols in FIG. 14. That is,
by virtue of the promotion of heat transfer by the heat
transfer-supporting ribs 92, it is achieved to make the increase in
the volume of the reforming passages 18 (the surface area of the
region in which the reforming catalyst 22 is supported) contribute
to the improvement in the conversion ratio. In addition, because
the region in which the heat transfer-supporting ribs 92 are
disposed is limited to the end portions on the gas inlet 50A-side,
or 51A-side, it is made possible to minimize the increase in the
pressure loss relative to that of the heat exchange reformer unit
80.
Fifth Embodiment
[0160] FIG. 19A shows a heat exchange reformer unit 100 according
to a fifth embodiment in a front view in section. FIG. 19B shows
the reforming passages 18 (combustion passages 20) constituting the
heat exchange reformer unit 100 in a plan view. As shown in these
figures, the heat exchange reformer unit 100 differs from the heat
exchange reformer unit 80 in including a multilayer core unit 104
in which such unit plate members 50 and 51 as described below are
stacked. Specifically, in the unit plate members 50 and 51, end
portions of the standing walls 56 on the gas inlet 50A-side, and
end portions of the standing walls 62 on the gas inlet 51A-side are
formed into heat transfer-supporting thick portions 102 as heat
transfer-promoting portions, which are thicker than the remaining
portions of the standing walls 56 and 62.
[0161] The heat transfer-supporting thick portions 102 are set
substantially corresponding to the reaction field in which the
combustion reactions mainly occur in the combustion passages 20,
that is, the region in which a large amount of heat is generated.
Thus, when regarded as heat transfer fins shown in FIG. 17, the
multilayer core unit 94 is rendered to have a configuration in
which the thickness d of the connecting portions between the plate
portions 52 are increased as compared to that of the third
embodiment, by providing the heat transfer-supporting thick
portions 102. When these are compared in terms of the fin
efficiency shown in FIG. 18, while the fin efficiency of the
multilayer core unit 82 of the heat exchange reformer unit 80 is
0.89, the fin efficiency of the multilayer core unit 104 of the
heat exchange reformer unit 100 is enhanced to 0.99.
[0162] In the other points, the configuration of the heat exchange
reformer unit 100 is the same as that of the heat exchange reformer
unit 80. Accordingly, as in the case of the heat exchange reformer
unit 10 according to the second embodiment, the heat exchange
reformer unit 100 according to the fifth embodiment also makes it
possible to match the total amount of the reforming reaction in the
reforming passages 18 and the total amount of the combustion
reaction in the combustion passages 20 (that is, to set the amount
of reforming reaction and the amount of combustion reaction
according to the reforming reaction field), and high space
velocities are therefore achieved. That is, it is possible to
improve reforming efficiency.
[0163] In the heat exchange reformer unit 100, the heat
transfer-supporting thick portions 102 promote heat transfer from
the combustion passages 20 to the reforming passages 18, especially
to the reforming passages 18 that are not adjacent to the
combustion passages 20 on either side of each reforming passage 18,
which cancels out the reduction in the thermal performance
(heat-transfer controlled effect) caused in the case of the third
embodiment. Thus, in the heat exchange reformer unit 100 (in which
the ratio of the volume occupied by the reforming passages 18 is
75%), the conversion ratio exceeding that of the heat exchange
reformer unit 10 is achieved under the operating conditions in
which the space velocity is high and the temperature of the
reformate gas is 650.degree. C., as shown by the solid symbols in
FIG. 14. That is, by virtue of the promotion of heat transfer by
the heat transfer-supporting thick portions 102, it is achieved to
make the increase in the volume of the reforming passages 18 (the
surface area of the region in which the reforming catalyst 22 is
supported) contribute to the improvement in the conversion ratio.
In addition, because the region in which the heat
transfer-supporting thick portions 102 are provided is limited to
the end portions on the gas inlet 50A-side, or 51A-side, it is made
possible to minimize the increase in the pressure loss relative to
that of the heat exchange reformer unit 80.
Sixth Embodiment
[0164] FIG. 20 shows a heat exchange reformer unit 110 according to
a sixth embodiment in a front view in section. As shown in this
figure, the heat exchange reformer unit 110 differs from the heat
exchange reformer unit 80 in including a multilayer core unit 116
that has, instead of part of the plate portions 52 and the standing
walls 56 constituting the unit plate member 50, plate portions 112
and standing walls 114 both constituting heat transfer-promoting
portions made of material (highly heat-conductive steel) having a
thermal conductivity higher than that of the plate portions 52 and
the standing walls 56.
[0165] The plate portion 112 is disposed except at the portions
constituting the combustion passages 20, in other words, so as to
separate the reforming passages 18 that are adjacent to each other
in the stacking direction. The standing walls 114 are disposed at
the positions such that the reforming passage 18 that is adjacent
to a combustion passage 20 is divided into the divided passages 58.
In FIG. 20, only the plate portions 112 and the standing walls 114
out of the components of the unit plate members 50 and 51 are
hatched.
[0166] Thus, when regarded as heat transfer fins shown in FIG. 17,
the multilayer core unit 116 is rendered to have a configuration in
which the thermal conductivity ? of each separation wall between
the reforming passages 18 that are adjacent to each other in the
stacking direction, and connecting portions having the thickness d
is increased as compared to that of the third embodiment, by
providing the plate portions 112 and the standing walls 114. When
these are compared in terms of the fin efficiency shown in FIG. 18,
while the fin efficiency of the multilayer core unit 82 of the heat
exchange reformer unit 80 is 0.89, the fin efficiency of the
multilayer core unit 116 of the heat exchange reformer unit 110 is
enhanced to 0.99.
[0167] In the other points, the configuration of the heat exchange
reformer unit 110 is the same as that of the heat exchange reformer
unit 80. Accordingly, as in the case of the heat exchange reformer
unit 10 according to the second embodiment, the heat exchange
reformer unit 110 according to the sixth embodiment also makes it
possible to match the total amount of the reforming reaction in the
reforming passages 18 and the total amount of the combustion
reaction in the combustion passages 20 (that is, to set the amount
of reforming reaction and the amount of combustion reaction
according to the reforming reaction field), and high space
velocities are therefore achieved.
[0168] In the heat exchange reformer unit 110, the plate portions
112 and the standing walls 114 promote heat transfer from the
combustion passages 20 to the reforming passages 18, especially to
the reforming passages 18 that are not adjacent to the combustion
passages 20 on either side of each reforming passage 18, which
cancels out the reduction in the thermal efficiency (heat-transfer
controlled effect) caused in the case of the third embodiment.
Thus, in the heat exchange reformer unit 110 (in which the ratio of
the volume occupied by the reforming passages 18 is 75%), the
conversion ratio exceeding that of the heat exchange reformer unit
10 is achieved under the operating conditions in which the space
velocity is high and the temperature of the reformate gas is
650.degree. C., as shown by the solid symbols in FIG. 14. That is,
by virtue of the promotion of heat transfer by the plate portions
112 and the standing walls 114, it is achieved to make the increase
in the volume of the reforming passages 18 (the surface area of the
region in which the reforming catalyst 22 is supported) contribute
to the improvement in the conversion ratio. In addition, because
the plate portions 112 and the standing walls 114 do not change of
the cross-sectional area of the reforming passages 18, the increase
in the pressure loss relative to that of the heat exchange reformer
unit 80 is avoided.
Seventh Embodiment
[0169] FIG. 21A shows a heat exchange reformer unit 120 according
to a seventh embodiment in a front view in section corresponding to
FIG. 8A. As shown in this figure, the heat exchange reformer unit
120 differs from the heat exchange reformer unit 10 that includes
the multilayer core unit 65 in which two layers of the reforming
passages 18 are stacked per one unit plate member 50, in including
a multilayer core unit 122 in which four unit plate members 50
(four layers of the reforming passages 18) are stacked per one unit
plate member 51 (one layer of the combustion passage 20).
[0170] Specifically, in the multilayer core unit 122, four layers
of the reforming passages 18 are disposed between a pair of the
combustion passages 20, as shown in FIG. 21B, by stacking the
units, in each of which four unit plate members 50 are stacked on
the same side of one unit plate member 51. Accordingly, in the
multilayer core unit 122, two layer of the reforming passages 18
are disposed so as to be sandwiched between two layers of the
reforming passages 18, each of which is, on any one side thereof,
adjacent to a combustion passage 20 with a plate portion 52
interposed therebetween in the stacking direction, that is, so as
not to be adjacent to the combustion passage 20 on either side of
the concerned reforming passage 18.
[0171] As described above, in the multilayer core unit 122 in which
four layers of the reforming passages 18 are stacked per one layer
of the combustion passage 20, the ratio of volume of the reforming
passages 18 to the overall volume is about 80%. In addition,
because the volume of one layer of the reforming passage 18 is
constant in the heat exchange reformer unit 120, the inner surface
area, that is, the catalyst-supporting region area (supporting
amount), of the combustion passages 20 is increased by about 60% as
compared to that of the heat exchange reformer unit 200.
[0172] In the other points, the configuration of the heat exchange
reformer unit 120 is the same as that of the heat exchange reformer
unit 10. Accordingly, as in the case of the heat exchange reformer
unit 10 according to the second embodiment, the heat exchange
reformer unit 120 according to the seventh embodiment also makes it
possible to match the total amount of the reforming reaction in the
reforming passages 18 and the total amount of the combustion
reaction in the combustion passages 20 (that is, to set the amount
of reforming reaction and the amount of combustion reaction
according to the reforming reaction field), and high space
velocities are therefore achieved. That is, it is possible to
improve reforming efficiency.
[0173] In the heat exchange reformer unit 120, in order to cancel
out the reduction in the thermal performance (heat-transfer
controlled effect) that results from the necessity to transport
heat to two layers of the reforming passages 18 per one layer of
the combustion passage 20, the heat transfer-supporting ribs 92,
the heat transfer-supporting thick portion 102, or both of the
plate portions 112 and the standing walls 114 (heat
transfer-promoting portion) may be provided.
[0174] Although, in the above embodiments, examples are illustrated
in which the heat exchange reformer unit is used in the fuel cell
system, the present invention is not limited to these embodiments.
The present invention is not limited by applications as long as the
heat exchange reformer unit is one of various heat exchange
reformer units for obtaining gas that contains hydrogen from
reformation material. Accordingly, the present invention is not
limited by the configuration of the water supply system. For
example, a configuration in which a water tank, water pipes, water
vaporizer etc. are provided as a water supply system may be
adopted.
[0175] In addition, although, in the above embodiments, examples
are illustrated in which the heat exchange reformer units 10, 80,
90, 100, 110 and 120 are each a parallel-flow heat exchange
reformer unit, the present invention is not limited to the
embodiments. The present invention may be applied to a cross-flow
heat exchange reformer unit, for example.
[0176] Moreover, in the above embodiments, examples are illustrated
in which one layer of the reforming passage 18 and one layer of the
combustion passage 20 have the same volume (cross section of
passage), the present invention is not limited to the embodiments.
A configuration in which one layer of the reforming passage 18 and
one layer of the combustion passage 20 have different volumes
(cross section of passage), for example.
* * * * *