JP2002284506A - Support structure of fuel reforming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple support structure for easing thermal stress concentration and avoiding damage and deterioration of a fuel reforming device and improving durability and efficiency. SOLUTION: In the support structure, the fuel reforming device 10 has a fuel burner 1, a reformer 2, a heat exchanger 3, a CO shift part 4, and a CO selective oxidizing part 5, which are united in a body and inserted in a package body 6, and is adhered to the inner wall 61 of the package body 6 with an elastic mount 81 by a bracket 8 at the joint part 41 between the CO shift part 4 and the heat exchanger 3, where is one point of the part having lower temperature or the necessary of lowering the temperature for the fuel reforming device 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support structure for a fuel reformer in which a fuel burner, a reformer, a heat exchanger, and a CO shift section are integrally formed and inserted into a package body.

[0002]

2. Description of the Related Art When a fuel reformer is packaged in combination with a fuel cell stack, it is necessary to support the fuel reformer in a package body because the weight is as large as 3 to 20 kg. Therefore, a part of the fuel reformer and the package body are connected and supported.

At this time, it is necessary to connect the package main body and a fuel reformer which becomes hot in an operating state, while paying attention to the following matters. While preventing heat dissipation loss,
Prevent lowering of reforming efficiency. Reduces thermal stress concentration and prevents damage and deterioration of the fuel reformer.

A fuel gas reforming apparatus for a fuel cell (Japanese Patent Laid-Open No.
153372) is a catalyst activation temperature range (180 ° C. to 30 ° C.) before the H 2 rich gas (about 600 ° C. to 750 ° C.) containing CO and H 2 O from the reforming section enters the shift section.
Since it is necessary to lower the temperature to about 0 ° C.), it is cooled through a heat exchanger.

At this time, the connecting portion N in FIG.
And heat exchanger C. Here, in the connection portion N, together with the cooling effect by the heat radiation of the gas, the concentration of the thermal stress at the connection portion between the reforming portion B and the heat exchange portion C due to the high-temperature gas is reduced, and the damage and deterioration of the fuel reforming device are prevented. Was something.

[0006] A conventional hydrogen-containing gas generator (JP-A-200
No. 0-159501), by integrating the fuel reforming device on the unit, the contact area between the device and the external air was reduced, and the reduction of the reforming efficiency due to the heat radiation of the fuel reforming device was prevented.

[0007]

The above-described structure of the conventional fuel gas reformer for a fuel cell has the following problems. Since the high-temperature gas passes through the pipe N, the heat transfer area in contact with the external air increases through the pipe. As a result, heat dissipation loss increases, and the reforming efficiency decreases.
In addition, when raising a problem at the time of packaging, it is necessary to hold a heat exchanger in addition to supporting the combustion unit and the reforming unit.

The structure of the above-mentioned conventional hydrogen-containing gas generator has the following two problems. Between the reforming section that requires a high temperature and the shift section that needs to be cooled down by about 400 ° C., it cannot be lowered to the activation temperature of the shift section,
The effect of the shift portion cannot be obtained to the maximum, and the reforming efficiency decreases with a decrease in the conversion rate of the fuel gas to H2 gas. High-temperature gas causes thermal stress concentration at a location where a temperature gradient is large, such as a connection portion between a reforming section and a heat exchange section, which easily leads to breakage and deterioration of the fuel reforming apparatus, thereby increasing durability.

Therefore, the present inventor has proposed a fuel reformer in which a fuel burner, a reformer, a heat exchanger, a CO shift section and a CO selective oxidizing section are integrally formed and inserted into a package body. At one point in the fuel reformer, where its temperature is relatively low or where it needs to be cooled,
Focusing on the technical idea of the present invention of sticking to the package body, further research and development have provided a simple support structure, alleviated thermal stress concentration, and avoided damage and deterioration of the fuel reformer Thus, the present invention has been achieved which achieves the object of increasing durability and efficiency.

[0010]

The supporting structure of the fuel reforming apparatus according to the present invention (first invention according to claim 1) comprises a fuel burner, a reformer, a heat exchanger, a CO shift section, and a CO selective oxidation. In a fuel reformer in which a part is integrally formed and inserted into the package body, the fuel reformer is provided with a package body at one point where the temperature is relatively low or where the temperature needs to be lowered. It is fixed to.

According to a second aspect of the present invention, there is provided a supporting structure for a fuel reforming apparatus, wherein the fuel reforming apparatus according to the first aspect of the present invention is configured such that the fuel reforming apparatus is provided between the CO shift unit and the heat exchanger. In the connection portion, the bracket is fixed to the inner peripheral wall of the package body via an elastic mount by a bracket.

According to a third aspect of the present invention, there is provided a support structure for a fuel reformer, wherein the fuel reformer according to the first aspect of the present invention is configured such that the fuel reformer is elastically supported by a bracket at one end of the fuel burner. The package is fixed to the inner peripheral wall of the package body via a mount.

[0013] In the support structure for a fuel reforming apparatus according to the present invention (fourth aspect of the present invention), in the second aspect, the package body may have a bottom having an opening formed at one end in an axial direction. The fuel burner is constituted by a hollow cylindrical body,
The CO shift unit and the heat exchanger are disposed on the inner peripheral wall, which is disposed at the opening at one end in the axial direction of the package body and is close to the bottom at the other end in the axial direction of the package body, via the bracket. The package is fixed to a connecting portion and configured to release heat generated from the fuel reformer through the opening at one end in the axial direction of the package body.

According to a fifth aspect of the present invention, there is provided a support structure for a fuel reformer according to the fourth aspect, wherein the support structure is provided between a lower portion of the fuel reformer and the bottom of the package body. A spring member is interposed and elastically supports the fuel reformer.

[0015]

According to the first aspect of the present invention, a fuel burner, a reformer, a heat exchanger, a CO shift unit and a CO selective oxidizing unit are integrally formed. In the fuel reformer inserted in the package body, the fuel reformer is fixed to the package body at one point where the temperature is relatively low or where the temperature needs to be lowered. The present invention provides an effective support structure, reduces the concentration of thermal stress, avoids damage and deterioration of the fuel reformer, and increases durability and efficiency. Further, since the fuel reforming device is fixed to the package body at a point where the temperature needs to be lowered, the temperature of the portion can be reduced and the efficiency of fuel reforming can be improved. To play.

According to the second aspect of the present invention, the fuel reformer according to the first aspect, wherein the fuel reformer includes a connecting portion between the CO shift portion having the lowest temperature and the heat exchanger. In the above, since the bracket is fixed to the inner peripheral wall of the package body via an elastic mount, concentration of thermal stress is reduced, and damage to the fuel reformer is prevented.
This has the effect of avoiding deterioration and increasing durability.

The support structure for a fuel reforming apparatus according to the third invention having the above-mentioned structure is characterized in that, in the first invention, the fuel reforming apparatus is configured such that the fuel reformer includes a package at one end of the fuel burner via an elastic mount by a bracket. Since the fuel reformer is fixed to the inner peripheral wall of the main body, the fuel reformer is elastically supported by a simple support structure.

In the supporting structure for a fuel reforming apparatus according to a fourth aspect of the present invention, the package body is a bottomed hollow cylinder having an opening at one end in the axial direction. The fuel burner is disposed in the opening at one end in the axial direction of the package main body, and the inner wall of the package main body near the bottom at the other end in the axial direction is provided with the CO shift portion via the bracket. Since it is fixed to the connection portion with the heat exchanger, the heat generated from the fuel reformer is released from the opening at one end in the axial direction of the package body. This has the effect of avoiding a rise in temperature.

According to a fifth aspect of the present invention, there is provided a supporting structure for a fuel reformer according to the fourth aspect, wherein a spring member is interposed between a lower portion of the fuel reformer and the bottom of the package body. Since the fuel reformer is elastically supported, the fuel reformer is more stably and elastically supported.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

(First Embodiment) As shown in FIGS. 1 to 4, the support structure of the fuel reforming apparatus of the first embodiment has a fuel burner 1, a reformer 2, a heat exchanger 3, a CO shift Part 4
And the CO selective oxidizing section 5 are integrally formed, and the fuel reforming apparatus 10 is inserted into the package main body 6. At a connection portion 41 between the portion 4 and the heat exchanger 3, an elastic mount 8 is provided by a bracket 8.
1 and is fixed to the inner wall 61 of the package body 6 through the first through-hole 1.

As shown in FIG. 2, the fuel reforming apparatus according to the first embodiment comprises a fuel burner 1 for burning 13A gas for fuel and combustion air, a reforming material and steam by combustion of the fuel burner. The reformer 2 for reforming the raw material, and the reforming raw material and steam in which water has been heat-exchanged with the exhaust gas in the evaporator 31 are heated in advance by the heat of the reforming gas discharged from the reformer 2. The heat exchanger 3 comprises a CO shift unit 4 made of a copper / zinc catalyst to which the heat-exchanged reformed gas is supplied, and a ruthenium catalyst after the shift. CO is produced by an oxidation reaction between the oxidized air and the reformed gas. Reduce CO
And a selective oxidation section 5.

The flange 41, which is the connection between the inlet of the CO shift unit 4 and the outlet of the heat exchange unit 3 in the fuel reformer 10, is bolted to the inner end 81 of the rectangular support bracket 8. And the outer end 82 opposite to the bracket 8 is fixed to the package body 6.

That is, the inner peripheral wall 6 of the package body 6
1, a flange portion 62 is integrally formed, and the flange portion 62 and the outer end portion 82 of the bracket 8 are fixed via a rubber mount 83.

As shown in FIGS. 3 and 4, the fuel reforming apparatus 10 is provided at one position of a flange portion 41 which is a connection portion between the inlet of the CO shift portion 4 and the outlet of the heat exchange portion 3 as shown in FIGS. The bracket is rigidly fixed to the package body 6 at two places on the left and right sides of the flange portion, and is not rigidly fixed to the package body 6 at two or more places on the left and right sides of the flange section 41 described above. .

As shown in FIG. 1, the package body 6 comprises a hollow body 60 having a bottom and an opening 63 formed at one end in the axial direction, and the opening at one end in the axial direction of the package body 6. On the inner wall near the part 63,
As shown in FIG. 3 and FIG. 4, the fuel reformer 10 is fixed to the connection portions 41 on both sides of the CO shift portion 4 and the heat exchanger 3 via the two rectangular brackets 8. I have.

Thus, regardless of the thermal expansion up to the reforming section 2 and the heat exchanging section 3 of the fuel reforming apparatus 10, the thermal stress is relaxed after the CO shift section 4 and the fuel reforming apparatus 10 10 is connected and supported with the package body 6.

The CO of about 650 ° C. which has exited from the reforming section 2
Before the H 2 -rich gas containing H 2 and H 2 O enters the CO shift section 4, the catalyst activation temperature range is from 180 ° C. to 3 ° C.
Since it is necessary to lower the temperature to about 00 ° C., it is cooled through the heat exchanger 3. The reformer 2 and the heat exchanger 3
The high temperature gas passes through the connection portion at the inlet of the thermal expansion.

On the other hand, the connection part 41 between the outlet of the heat exchange part 3 and the inlet of the CO shift part 4 has a lower temperature than the connection part 41.
Since the gas of about 50 ° C. passes, the package reformer 10 having a low temperature and the fuel reformer 10 having a high temperature in an operation state
Can be connected at a place where the temperature difference is small, and the fuel reformer 10 is supported at a place where the temperature needs to be lowered.

The support structure of the fuel reformer of the first embodiment realizes the following advantages from the above. Since the lowest temperature portion of the fuel reformer 10 is supported by the package body 6, which is at a low temperature, the reforming efficiency is prevented from lowering while preventing heat loss. The fuel reformer 1
0 and the package main body 6 are supported at a portion where the temperature difference is the smallest, so that damage and deterioration of the fuel reformer 10 due to relaxation of thermal stress concentration can be prevented.

In the support structure of the fuel reforming apparatus according to the first embodiment, the temperature of the CO shift unit 4 is reduced as described above, so that as shown in FIG. The shift reaction is shifted to the right to reduce the CO concentration and increase the amount of hydrogen.

Embedded image

Further, the CO concentration with respect to the shift catalyst temperature, which is the actually measured value of the CO concentration at the outlet in the CO shift section 4, is as shown in FIG.

Since the support position (mount position) of the fuel reformer 10 in the support structure of the fuel reformer of the first embodiment is a CO shift portion, as shown in Table 1, The temperature is 631 ° C., the outlet temperature of the CO shift unit 4 is 120 ° C., and the thermal efficiency is 73.2%
Met.

[Table 1]

In other words, by mouting in the CO shift unit 4, the reforming loss can be reduced, a decrease in thermal efficiency can be prevented, and the temperature of the CO shift unit 4 can be lowered.

Further, the effect of the combustion direction corresponding to the direction in which the fuel reformer 10 is disposed in the package body 6 will be examined. That is, in the first embodiment, as shown in FIG.
Since the combustion flame is ejected upward, malfunction may occur due to dew condensation, that is, foreign matter falling into the burner due to foreign matter falling, such as heat insulation, and adversely affect ignition performance and complete combustion. give.

(Second Embodiment) As shown in FIG. 5, the support structure of the fuel reformer according to the second embodiment
The first embodiment is different from the first embodiment in that the second embodiment is fixed to the inner peripheral wall 61 of the package body 6 via the elastic mount 81 by the following method.

That is, a plunge portion as a connecting portion which is formed on the outer peripheral wall of the upper end base portion 11 of the combustion burner 1 in the fuel reformer 10 and is fixed to a flange portion 21 as a connecting portion of the reforming portion 2. 12 and the flange portion 21 of the reforming section 2 are fixed to the inner end portion 81 of the bracket 8 by bolts, and the outer end portion 82 of the bracket 8 is connected to the package via an elastic mount 81. It is fixed to a flange 62 projecting from an inner peripheral wall 61 of the main body 6 by a bolt.

The package body 6 is constituted by a bottomed hollow cylindrical body 60 having an opening 63 formed at one end in the axial direction, and an inner peripheral wall close to the opening 63 at one end in the axial direction of the package body 6. In the above, the bracket 8
The fuel reformer 10 is fixed to a flange portion 12 as a connection portion of an upper end base portion 11 of the combustion burner 1 of the fuel reformer 10.

The fuel reformer 10 includes a plunge 12 as a connecting portion of an upper end base 11 of the combustion burner 1.
It is rigidly fixed to the package body 6 at a point.

The support structure of the fuel reforming apparatus according to the second embodiment is configured such that the above-described support structure allows the thermal stress to be relaxed regardless of the thermal expansion of the portion after the reforming section 2 of the fuel reforming apparatus 10. At the same time, the fuel reformer 10 and the package body 6 are connected and supported.

By supporting the fuel reformer 10 in the flange portion 12 which is a relatively low temperature portion near the fuel / air and anode off-gas introduction portion of the fuel burner 1, the following advantages are obtained. Realize.

Since the temperature difference is small even when the package body 6 is connected to the low-temperature package body 6 via the bracket 8, heat loss due to heat transfer can be reduced, and a decrease in reforming efficiency can be prevented.

The plunge section 1 of the upper end base 11 of the combustion burner 1 which is a part of the fuel reformer 10 which is a part of the fuel reformer 10 which is a part of the fuel reformer 10 which becomes a high temperature in the operating state.
2 is supported by a support bracket 8, and the outer peripheral end of the support bracket 8 on the opposite side is connected to and supported by the package body 6.

In the second embodiment, since the connection is made at a location where the temperature difference is small, that is, at a location where the temperature is relatively low or needs to be lowered in the fuel reforming apparatus 10, the following connection is required. The benefits are realized. This is to prevent the reforming efficiency from decreasing while preventing the heat loss. At one or more points, a thermal stress relaxation mechanism is provided to prevent the fuel reformer 10 from being damaged or deteriorated. This realizes a rigid mechanism at one place.

Further, since the support position (mount position) of the fuel reformer 10 in the support structure of the fuel reformer of the second embodiment is the reforming section (combustion burner), as shown in Table 1. The temperature of the reformed gas is 604 ° C.
The outlet temperature of the O shift unit 4 is 141 ° C., and the thermal efficiency is 6
7.5%.

That is, by mouting in the combustion burner 1 of the reforming section 2 having a high temperature, heat loss increases and reforming loss decreases.

Further, the effect of the combustion direction corresponding to the direction in which the fuel reformer 10 is disposed in the package body 6 will be examined. That is, in the second embodiment, as shown in FIG.
Since the combustion flame is ejected downward, there is little foreign matter intrusion into the burner, but growth of the combustion flame is suppressed.

(Third Embodiment) The support structure of the fuel reformer according to the third embodiment is the same as that of the second embodiment shown in FIG.
As shown in FIG.
Is changed to a connection part 42 between the CO shift part 4 and the CO selective oxidation part, and a spring member 9 is inserted between a lower part of the fuel reformer 10 and a bottom part of the package body 6, The difference from the first embodiment is that the fuel reformer 10 is elastically supported, and the following description will focus on the differences.

In the third embodiment, as shown in FIG. 7, the inner wall of the package main body 6 is not rigidly fixed to the package main body 6 at two or more locations of the fuel reformer 10. 61 flange 6
2 and the support bracket 8 for supporting the outer peripheral wall of the fuel reformer 10 are fixed rigidly by bolts directly via a ceramics sheet as a heat insulating material without a rubber mount as in the above-described embodiment. It is fixed.

As shown in FIG. 7, the support bracket 8 is constituted by a stay 80 of SS400, and an inner end 81 is provided at the CO shift portion 4 of the fuel reformer 10.
And a metal gasket 45 between the CO selective oxidizing unit 5 and the CO selective oxidizing unit 5.

Further, the CO in the lower part of the fuel reformer 10
Lower surface of selective oxidation section 5 and lower surface 64 of package body 6
A plurality of coil spring members 91 are interposed as spring members 9 between the first and second members, and the lower portion of the fuel reformer 10 is elastically supported.

In the support structure of the fuel reformer of the third embodiment, the fuel reformer 10 is rigidly fixed at the first location and elastically supported at the second location. This has the effect of reducing the concentration of thermal expansion and thermal stress of the device 10.

(Fourth Embodiment) The support structure of the fuel reformer according to the fourth embodiment is the same as that of the third embodiment shown in FIG.
As shown in FIG. 7, the supporting portion on the outer peripheral wall of the fuel reformer 10 supported on the inner peripheral wall of the package body 6 is connected to the connecting portion 41 between the heat exchanger 3 and the CO shift unit 4 as in the first embodiment. The changed points are the differences from the third embodiment, and the following description will focus on the differences.

In the support structure of the fuel reforming apparatus according to the fourth embodiment, the fuel reforming apparatus 10 is fixed to a rigid portion at the first position and elastically supported at the second position.
As in the embodiment, there is an effect that the concentration of thermal expansion and thermal stress of the fuel reformer 10 is reduced.

The above-described embodiments have been described by way of example only, and the present invention is not limited to these embodiments. Those skilled in the art will recognize from the claims, the detailed description of the invention, and the drawings. Modifications and additions are possible without departing from the technical idea of the present invention.

In the above-described embodiment, the example of the support structure of the fuel reformer has been described. However, the present invention is not limited to this. For example, as shown in FIG. The support stays are integrally connected to the position offset from the connection part by welding,
As shown in FIG. 13, a reinforcing rib 8R and a radiation fin 8F are formed on the support stay, and a number of circular holes are formed in the support stay as shown in FIG. 14 to promote cooling of the support stay and the shift portion. However, even when a low-temperature refrigerant is used, an embodiment that enables shift cooling while maintaining the active temperature range of the catalyst can be adopted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a support structure of a fuel reformer according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a fuel cell system to which the fuel reformer of the first embodiment is applied.

FIG. 3 is a partial plan view showing a support structure of the fuel reformer of the first embodiment.

FIG. 4 is a partially cutaway sectional view showing a support structure of the fuel reforming apparatus of the first embodiment.

FIG. 5 is a sectional view showing a support structure of a fuel reforming apparatus according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing a support structure of a fuel reformer according to a third embodiment of the present invention.

FIG. 7 is a partially cutaway sectional view showing a support structure of a fuel reformer according to a third embodiment.

FIG. 8 is a sectional view showing a support structure of a fuel reforming apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a diagram showing a relationship between a shift temperature and a CO concentration in the first embodiment.

FIG. 10 shows shift catalyst temperature and C in the first embodiment.
It is a diagram which shows the relationship of O concentration.

FIG. 11 is an explanatory diagram for explaining an influence of a combustion direction in the present embodiment.

FIG. 12 is a partially cutaway sectional view showing another embodiment of the support structure of the fuel reforming apparatus according to the present invention.

FIG. 13 is a partially cutaway sectional view showing another embodiment of the support structure of the fuel reforming apparatus according to the present invention.

FIG. 14 is a partially cutaway sectional view showing another embodiment of the support structure of the fuel reforming apparatus according to the present invention.

FIG. 15 is a sectional view showing a conventional fuel gas reformer for a fuel cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel burner 2 Reformer 3 Heat exchanger 4 CO shift part 5 CO selective oxidation part 6 Package body 8 Bracket 10 Fuel reformer 41 Connection part 61 Inner wall 81 Elastic mount

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G040 EA03 EA06 EB31 EB32 EB42 EB46 4G140 EA03 EA06 EB31 EB32 EB42 EB46 5H027 AA02 BA01 BA17

Claims (5)

[Claims] 1. A fuel reformer, wherein a fuel burner, a reformer, a heat exchanger, a CO shift unit and a CO selective oxidizing unit are integrally formed and inserted into a package body. However, a support structure for a fuel reformer, wherein the support structure is fixed to a package body at one point where the temperature is relatively low or where the temperature needs to be lowered. 2. The package according to claim 1, wherein the fuel reformer is fixed to an inner peripheral wall of the package body via a resilient mount by a bracket at a connection between the CO shift unit and the heat exchanger. A support structure for a fuel reformer. 3. The fuel reformer according to claim 1, wherein the fuel reformer is provided at one end of the fuel burner.
A support structure for a fuel reformer, wherein the bracket is fixed to an inner peripheral wall of the package body via an elastic mount by a bracket. 4. The package body according to claim 2, wherein the package body is formed by a hollow cylinder with a bottom having an opening formed at one end in the axial direction, and the fuel burner is provided at one end in the axial direction of the package body. The package body is fixed to a connection portion between the CO shift unit and the heat exchanger via the bracket on an inner peripheral wall near the bottom at the other end in the axial direction of the package body. A support structure for a fuel reformer, characterized in that heat generated from the fuel reformer is released from the opening at one end in the axial direction. 5. The fuel cell system according to claim 4, wherein a spring member is interposed between a lower portion of the fuel reformer and the bottom of the package body to elastically support the fuel reformer. Characteristic fuel reformer support structure.